WorldWideScience

Sample records for chemical cleaning process

  1. Chemical-cleaning process evaluation: Westinghouse steam generators. Final report

    International Nuclear Information System (INIS)

    Cleary, W.F.; Gockley, G.B.

    1983-04-01

    The Steam Generator Owners Group (SGOG)/Electric Power Research Institute (EPRI) Steam Generator Secondary Side Chemical Cleaning Program, under develpment since 1978, has resulted in a generic process for the removal of accumulated corrosion products and tube deposits in the tube support plate crevices. The SGOG/EPRI Project S150-3 was established to obtain an evaluation of the generic process in regard to its applicability to Westinghouse steam generators. The results of the evaluation form the basis for recommendations for transferring the generic process to a plant specific application and identify chemical cleaning corrosion guidelines for the materials in Westinghouse Steam Generators. The results of the evaluation, recommendations for plant-specific applications and corrosion guidelines for chemical cleaning are presented in this report

  2. Material compatibility and corrosion control of the KWU chemical cleaning process

    International Nuclear Information System (INIS)

    Odar, S.

    1994-01-01

    The concentrations of salt impurities within the deposits on the tube sheet and in the tube to tube-support-plate crevices can induce a variety of corrosion mechanisms on steam generator tubes. One of the most effective ways of counteracting corrosion mechanisms and thus of improving steam generator performance is to clean the steam generators and keep them in a clean condition. As shown by field results chemical cleaning is a way of removing hazardous deposits from steam generators. All available chemical cleaning processes use inhibitors to control the corrosion except the KWU chemical cleaning process. In this article the corrosion control technique of KWU Chemical Cleaning Process without using conventional inhibitors will be explained and the state of the field experience with respect to material compatibility will be presented. (author). 4 figs., 1 tab., 8 refs

  3. Waste processing of chemical cleaning solutions

    International Nuclear Information System (INIS)

    Peters, G.A.

    1991-01-01

    This paper reports on chemical cleaning solutions containing high concentrations of organic chelating wastes that are difficult to reduce in volume using existing technology. Current methods for evaporating low-level radiative waste solutions often use high maintenance evaporators that can be costly and inefficient. The heat transfer surfaces of these evaporators are easily fouled, and their maintenance requires a significant labor investment. To address the volume reduction of spent, low-level radioactive, chelating-based chemical cleaning solutions, ECOSAFE Liquid Volume Reduction System (LVRS) has been developed. The LVRS is based on submerged combustion evaporator technology that was modified for treatment of low-level radiative liquid wastes. This system was developed in 1988 and was used to process 180,000 gallons of waste at Oconee Nuclear Station

  4. Field experience with KWU SG chemical cleaning process

    International Nuclear Information System (INIS)

    Odar, S.

    1989-01-01

    The ingress of corrosion products into PWR steam generators (SG's) their deposition and the subsequent concentration of salt impurities can induce a variety of mechanisms for corrosion attack on SG tubing. Already, some plants have had to replace their steam generators due to severe corrosion damage and others are seriously considering the same costly action in the near future. One of the most effective ways to counteract corrosion mechanisms and thus to reduce the likelihood of SG replacement becoming necessary is to clean the SG's and to keep them clean. For many years, the industry has been involved in developing different types of cleaning techniques. Among these, chemical cleaning has been shown to be especially effective. In this article, the KWU chemical cleaning process, for which there is considerable application experience, is described. The results of field applications will be presented together with material compatibility data and information on cleaning effectiveness. (author)

  5. Chemical cleaning review

    International Nuclear Information System (INIS)

    Dow, B.L.; Thomas, R.C.

    1995-01-01

    Three main chemical processes for cleaning steam generators have evolved from the early work of the industry. Of the more than 50 chemical cleanings carried out to date most have been considered a success by the utilities performing them. (author)

  6. PWR steam generator chemical cleaning. Phase I: solvent and process development. Volume II

    International Nuclear Information System (INIS)

    Larrick, A.P.; Paasch, R.A.; Hall, T.M.; Schneidmiller, D.

    1979-01-01

    A program to demonstrate chemical cleaning methods for removing magnetite corrosion products from the annuli between steam generator tubes and the tube support plates in vertical U-tube steam generators is described. These corrosion products have caused steam generator tube ''denting'' and in some cases have caused tube failures and support plate cracking in several PWR generating plants. Laboratory studies were performed to develop a chemical cleaning solvent and application process for demonstration cleaning of the Indian Point Unit 2 steam generators. The chemical cleaning solvent and application process were successfully pilot-tested by cleaning the secondary side of one of the Indian Point Unit 1 steam generators. Although the Indian Point Unit 1 steam generators do not have a tube denting problem, the pilot test provided for testing of the solvent and process using much of the same equipment and facilities that would be used for the Indian Point Unit 2 demonstration cleaning. The chemical solvent selected for the pilot test was an inhibited 3% citric acid-3% ascorbic acid solution. The application process, injection into the steam generator through the boiler blowdown system and agitation by nitrogen sparging, was tested in a nuclear environment and with corrosion products formed during years of steam generator operation at power. The test demonstrated that the magnetite corrosion products in simulated tube-to-tube support plate annuli can be removed by chemical cleaning; that corrosion resulting from the cleaning is not excessive; and that steam generator cleaning can be accomplished with acceptable levels of radiation exposure to personnel

  7. Steam generators secondary side chemical cleaning at Point Lepreau using the Siemen's high temperature process

    International Nuclear Information System (INIS)

    Verma, K.; MacNeil, C.; Odar, S.

    1996-01-01

    The secondary sides of all four steam generators at the Point Lepreau Nuclear Generating Stations were cleaned during the 1995 annual outage run-down using the Siemens high temperature chemical cleaning process. Traditionally all secondary side chemical cleaning exercises in CANDU as well as the other nuclear power stations in North America have been conducted using a process developed in conjunction with the Electric Power Research Institute (EPRI). The Siemens high temperature process was applied for the first time in North America at the Point Lepreau Nuclear Generating Station (PLGS). The paper discusses experiences related to the pre and post award chemical cleaning activities, chemical cleaning application, post cleaning inspection results and waste handling activities. (author)

  8. Benefits of integrating chemical and mechanical cleaning processes for steam generator sludge removal

    International Nuclear Information System (INIS)

    Varrin, R.D.; Ferriter, A.M.; Oliver, T.W.; Le Surf, J.E.

    1992-01-01

    This paper discusses the benefits of performing in-bundle tubesheet lancing in conjunction with chemical cleaning of PWR and PHWR steam generators in which a hard sludge pile is known to exist. The primary benefits of in-bundle lancing are to: (1) increase the exposed area of the sludge pile by cutting furrows in the surface thereby enhancing dissolution of sludge, (2) reduce the volume of solvents required since material removed by lancing does not have to be dissolved chemically, (3) improve rinsing and removal of residual solvent between iron and copper dissolution steps, and (4) allow for verification of process effectiveness by providing high quality in-bundle visual inspection. The reduction in solvent volumes can lead to a significant reduction in solvent costs and waste processing. A case study which includes an economic evaluation for a combined chemical and mechanical cleaning shows a potential cost saving of up to US$ 300,000 over use of chemical cleaning alone. 14 refs., 2 tabs., 2 figs

  9. Chemical cleaning of UK AGR boilers

    International Nuclear Information System (INIS)

    Rudge, A.; Turner, P.; Ghosh, A.; Clary, W.; Tice, D.

    2002-01-01

    For the first time in their operational lives, UK advanced gas-cooled reactor once-through boilers have been chemically cleaned. Chemical cleaning was necessary to avoid lost output resulting from boiler pressure drops, which had been increasing for a number of years. Chemical cleaning of these boilers presents a number of unique difficulties. These include lack of access to the boilers, highly sensitised 316H superheater sections that cannot be excluded from the cleaning flow path, relatively thin boiler tube walls and an intolerance to boiler tube failure because of the role of the boilers in nuclear decay heat removal. The difficulties were overcome by implementing the clean in a staged manner, starting with an extensive materials testwork programme to select and then to substantiate the cleaning process. The selected process was based on ammoniated citric acid plus formic acid for the principal acid cleaning stage. Materials testwork was followed by an in-plant trial clean of six boiler tubes, further materials testwork and the clean of a boiler tube in a full-scale test rig. An overview is presented of the work that was carried out to demonstrate that the clean could be carried out safely, effectively and without leading to unacceptable corrosion losses. Full-scale chemical cleaning was implemented by using as much of the existing plant as possible. Careful control and monitoring was employed to ensure that the cleaning was implemented according to the specified design, thus ensuring that a safe and effective clean was carried out. Full-scale cleaning has resulted in significant boiler pressure drop recovery, even though the iron burden was relatively low and cleaning was completed in a short time. (orig.)

  10. Pickering Unit 1 chemical cleaning

    International Nuclear Information System (INIS)

    Smee, J.L.; Fiola, R.J.; Brennenstuhl, K.R.; Zerkee, D.D.; Daniel, C.M.

    1995-01-01

    The secondary sides of all 12 boilers at Pickering Unit 1 were chemically cleaned in 1994 by the team of Ontario Hydro, B and W International (Cambridge, Ontario) and B and W Nuclear Technologies (Lynchburg, Virginia). A multi-step EPRI/SGOG process was employed in a similar manner to previous clearings at Units 5 and 6 in 1992 and 1993, respectively. A major innovation with the Unit 1 cleaning was the incorporation of a crevice cleaning step, the first time this had been done on Ontario Hydro plants. In addition, six boilers were cleaned in parallel compared to three at a time in previous Pickering cleanings. This significantly reduced cleaning time. A total of 6,770 kg of sludge was removed through direct chemical dissolution. It consisted of 66% iron/nickel oxides and 28% copper metal. A total of 1,600,000 L (420,000 US gallons) of liquid waste was produced. It was processed through the spent solvent treatment facility located at the Bruce Nuclear Power Development site. Visual inspection performed after the cleaning indicated that the crevices between the boiler tubes and the tube support structure were completely clear of deposit and the general condition of the tubing and lattice bars appeared to be in 'as new' condition. (author)

  11. Chemical cleaning, decontamination and corrosion

    International Nuclear Information System (INIS)

    Gadiyar, H.S.; Das Chintamani; Gaonkar, K.B.

    1991-01-01

    Chemical cleaning of process equipments and pipings in chemical/petrochemical industries is necessitated for improving operation, for preventing premature failures and for avoiding contamination. In developing a chemical formulation for cleaning equipments, the important aspects to be considered include (i) effective removal of corrosion products and scales, (ii) minimum corrosion of the base metal, (iii) easy to handle chemicals and (iv) economic viability. As on date, a wide variety of chemical formulations are available, many of them are either proprietory or patented. For evolving an effective formulation, knowledge of the oxides of various metals and alloys on the one hand and acid concentration, complexing agents and inhibitors to be incorporated on the other, is quite essential. Organic acids like citric acid, acetic acid and formic acid are more popular ones, often used with EDTA for effective removal of corrosion products from ferrous components. The report enumerates some of the concepts in developing effective formulations for chemical cleaning of carbon steel components and further, makes an attempt to suggest simple formulations to be developed for chemical decontamination. (author). 6 refs., 3 fi gs., 4 tabs

  12. ANALYSIS OF SAMPLES FROM TANK 5F CHEMICAL CLEANING

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M.; Fink, S.

    2011-03-07

    The Savannah River Site (SRS) is preparing Tank 5F for closure. The first step in preparing the tank for closure is mechanical sludge removal. Following mechanical sludge removal, SRS performed chemical cleaning with oxalic acid to remove the sludge heel. Personnel are currently assessing the effectiveness of the chemical cleaning. SRS personnel collected liquid samples during chemical cleaning and submitted them to Savannah River National Laboratory (SRNL) for analysis. Following chemical cleaning, they collected a solid sample (also known as 'process sample') and submitted it to SRNL for analysis. The authors analyzed these samples to assess the effectiveness of the chemical cleaning process. The conclusions from this work are: (1) With the exception of iron, the dissolution of sludge components from Tank 5F agreed with results from the actual waste demonstration performed in 2007. The fraction of iron removed from Tank 5F by chemical cleaning was significantly less than the fraction removed in the SRNL demonstrations. The likely cause of this difference is the high pH following the first oxalic acid strike. (2) Most of the sludge mass remaining in the tank is iron and nickel. (3) The remaining sludge contains approximately 26 kg of barium, 37 kg of chromium, and 37 kg of mercury. (4) Most of the radioactivity remaining in the residual material is beta emitters and {sup 90}Sr. (5) The chemical cleaning removed more than {approx} 90% of the uranium isotopes and {sup 137}Cs. (6) The chemical cleaning removed {approx} 70% of the neptunium, {approx} 83% of the {sup 90}Sr, and {approx} 21% of the {sup 60}Co. (7) The chemical cleaning removed less than 10% of the plutonium, americium, and curium isotopes. (8) The chemical cleaning removed more than 90% of the aluminium, calcium, and sodium from the tank. (9) The cleaning operations removed 61% of lithium, 88% of non-radioactive strontium, and 65% of zirconium. The {sup 90}Sr and non-radioactive strontium were

  13. Chemical cleaning for sludge in steam generator of nuclear power plant

    International Nuclear Information System (INIS)

    Zhang Mengqin; Lu Yucheng; Zhang Binyong; Yu Jinghua

    2002-01-01

    The sludge induced corrosion damage to secondary side of tubes of Steam Generator (SG), effect of chemical cleaning technique on maintenance integrity of tubes of SG NPP and use of chemical cleaning technique in SG NPP have been summarized. The engineering technique of chemical cleaning for removing sludge in secondary side of SG NPP has been studied and qualified by CIAE (China Institute of Atomic Energy). Chemical cleaning engineering technique is introduced (main agent is EDTA, temp. <100 degree C), including chemical cleaning technology for tube plate and full tube nest of secondary side of SG, the monitoring technique of chemical cleaning process (effectiveness and safety), the disposal method of wastage of chemical cleaning, the system of chemical cleaning. The method for preventing sludge deposition in secondary side and the research on advanced water chemistry of secondary loop are introduced

  14. Three Mile Island Nuclear Station steam generator chemical cleaning

    International Nuclear Information System (INIS)

    Hansen, C.A.

    1992-01-01

    The Three Mile Island-1 steam generators were chemically cleaned in 1991 by the B and W Nuclear Service Co. (BWNS). This secondary side cleaning was accomplished through application of the EPRI/SGOG (Electric Power Research Institute - Steam Generator Owners Group) chemical cleaning iron removal process, followed by sludge lancing. BWNS also performed on-line corrosion monitoring. Corrosion of key steam generator materials was low, and well within established limits. Liquid waste, subsequently processed by BWNS was less than expected. 7 tabs

  15. Processes of elimination of activated corrosion products. Chemical decontamination - fuel cleaning

    International Nuclear Information System (INIS)

    Viala, C.; Brun, C.; Neuhaus, R.; Richier, S.; Bachet, M.

    2007-01-01

    The abatement of the individual and collective dose of a PWR imposes to control the source term through different processes implemented during the plant exploitation. When the limits of these different optimization processes are reached, the abatement of dose rates requires the implementation of curative processes. The objective is thus to eliminate the contaminated oxides and deposits present on surfaces free of radiation flux, and eventually on surfaces under radiation flux and on the fuel itself. The chemical decontamination of equipments and systems is the main and universal remedy implemented at different levels. On the other hand, the ultrasonic cleaning of fuel assemblies is a promising process. This paper aims at illustrating these different techniques using concrete examples of application in France and abroad (decontamination during steam generator replacement, decontamination of primary pump scroll in hot workshop, decontamination of loop sections, ultrasonic cleaning of fuel). The description of these different operations stresses on their efficiency in terms of dosimetric gain, duration of implementation, generation of wastes, and recontamination following their implementation. (J.S.)

  16. Oxalate Mass Balance During Chemical Cleaning in Tank 5F

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M.; Fink, S.

    2011-07-08

    The Savannah River Site (SRS) is preparing Tank 5F for closure. The first step in preparing the tank for closure is mechanical sludge removal. Following mechanical sludge removal, SRS performed chemical cleaning with oxalic acid to remove the sludge heel. Personnel are currently assessing the effectiveness of the chemical cleaning to determine whether the tank is ready for closure. SRS personnel collected liquid samples during chemical cleaning and submitted them to Savannah River National Laboratory (SRNL) for analysis. Following chemical cleaning, they collected a solid sample (also known as 'process sample') and submitted it to SRNL for analysis. The authors analyzed these samples to assess the effectiveness of the chemical cleaning process. Analysis of the anions showed the measured oxalate removed from Tank 5F to be approximately 50% of the amount added in the oxalic acid. To close the oxalate mass balance, the author collected solid samples, leached them with nitric acid, and measured the concentration of cations and anions in the leachate.

  17. A study on the chemical cleaning process and its qualification test by eddy current testing

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ki Seok; Cheon, Keun Young; Nam, Min Woo [KHNP Central Research Institute, Daejeon (Korea, Republic of); Min, Kyoung Mahn [UMI Inc., Daejeon (Korea, Republic of)

    2013-12-15

    Steam Generator (SG) tube, as a barrier isolating the primary coolant system from the secondary side of nuclear power plants (NPP), must maintain the structural integrity for the public safety and their efficient power generation. So, SG tubes are subject to the periodic examination and the repairs if needed so that any defective tubes are not in service. Recently, corrosion related degradations were detected in the tubes of the domestic OPR-1000 NPP, as a form of axially oriented outer diameter stress corrosion cracking (ODSCC). According to the studies on the factors causing the heat fouling as well as developing corrosion cracking, densely scaled deposits on the secondary side of the SG tubes are mainly known to be problematic causing the adverse impacts against the soundness of the SG tubes. Therefore, the processes of various cleaning methods efficiently to dissolve and remove the deposits have been applied as well as it is imperative to maintain the structural integrity of the tubes after exposing to the cleaning agent. So qualification test (QT) should be carried out to assess the perfection of the chemical cleaning and QT is to apply the processes and to do ECT. In this paper, the chemical cleaning processes to dissolve and remove the scaled deposits are introduced and results of ECT on the artificial crack specimens to determine the effectiveness of those processes are represented.

  18. Medium scale test study of chemical cleaning technique for secondary side of SG in PWR

    International Nuclear Information System (INIS)

    Zhang Mengqin; Zhang Shufeng; Yu Jinghua; Hou Shufeng

    1997-08-01

    The medium scale test study of chemical cleaning technique for removing corrosion product (Fe 3 O 4 ) in secondary side of SG in PWR has been completed. The test has been carried out in a medium scale test loop. The medium scale test evaluated the effect of the chemical cleaning technique (temperature, flow rate, cleaning time, cleaning process), the state of corrosion product deposition on magnetite (Fe 3 O 4 ) solubility and safety of materials of SG in cleaning process. The inhibitor component of chemical cleaning agent has been improved by electrochemical linear polarization method, the effect of inhibitor on corrosion resistance of materials have been examined in the medium scale test loop, the most components of chemical cleaning agent have been obtained, the EDTA is main component in cleaning agent. The electrochemical method for monitor corrosion of materials during cleaning process has been completed in the laboratory. The study of the medium scale test of chemical cleaning technique have had the optimum chemical cleaning technique for remove corrosion product in SG secondary side of PWR. (9 refs., 4 figs., 11 tabs.)

  19. Effectiveness of bone cleaning process using chemical and entomology approaches: time and cost.

    Science.gov (United States)

    Lai, Poh Soon; Khoo, Lay See; Mohd Hilmi, Saidin; Ahmad Hafizam, Hasmi; Mohd Shah, Mahmood; Nurliza, Abdullah; Nazni, Wasi Ahmad

    2015-08-01

    Skeletal examination is an important aspect of forensic pathology practice, requiring effective bone cleaning with minimal artefact. This study was conducted to compare between chemical and entomology methods of bone cleaning. Ten subjects between 20 and 40 years old who underwent uncomplicated medico-legal autopsies at the Institute of Forensic Medicine Malaysia were randomly chosen for this descriptive cross sectional study. The sternum bone was divided into 4 parts, each part subjected to a different cleaning method, being two chemical approaches i.e. laundry detergent and a combination of 6% hydrogen peroxide and powder sodium bicarbonate and two entomology approaches using 2nd instar maggots of Chrysomyia rufifacies and Ophyra spinigera. A scoring system for grading the outcome of cleaning was used. The effectiveness of the methods was evaluated based on average weight reduction per day and median number of days to achieve the average score of less than 1.5 within 12 days of the bone cleaning process. Using maggots was the most time-effective and costeffective method, achieving an average weight reduction of 1.4 gm per day, a median of 11.3 days to achieve the desired score and an average cost of MYR 4.10 per case to reach the desired score within 12 days. This conclusion was supported by blind validation by forensic specialists achieving a 77.8% preference for maggots. Emission scanning electron microscopy evaluation also revealed that maggots especially Chrysomyia rufifacies preserved the original condition of the bones better allowing improved elucidation of bone injuries in future real cases.

  20. Noncontact COS charge analysis for in-line monitoring of wet cleaning processes

    Science.gov (United States)

    Zhang, Xiafang; Juang, Min; Tai, Sung-Shan; Chen, Kuo-in; Wossen, Ejigu; Horner, Gregory

    1998-08-01

    Contamination levels in chemical cleaning equipment and wafer cleanliness in general are very critical to semiconductor manufacturers. In this work, a Keithley Instruments non contact electrical tester (Quantox) is used to measure the mobile ion (Qm) contamination in a variety of cleaning processes. Results show that photoresist strip cleaning process has a higher mobile ion concentration than standard pre-diffusion cleaning process. RCA1, RCA2 and HF solutions mapping measured by the Quantox indicates some negative static charges on the surface after cleaning. This negative field appears to assist Qm removal during wet chemical cleaning. The dependence of flatband voltage and other oxide charges on various cleaning processes has also been investigated using the Quantox. The data suggests that a dipole layer has been formed by a surface reaction during chemical cleaning.

  1. Update-processing steam generator cleaning solvent at Palo Verde

    International Nuclear Information System (INIS)

    Peters, G.

    1996-01-01

    Framatome Technologies Inc.(FTI) recently completed the steam generator chemical cleanings at the Palo Verde Nuclear Generating Station Units 1, 2 and 3. Over 500,000 gallons of low-level radioactive solvents were generated during these cleanings and were processed on-site. Chemical cleaning solutions containing high concentrations of organic chelating wastes are difficult to reduce in volume using standard technologies. The process that was ultimately used at Palo Verde involved three distinct processing steps: The evaporation step was conducted using FTI's submerged combustion evaporator (SCE) that has also been successfully used at Arkansas Nuclear One - Unit 1, Three Mile Island - Unit 1, and Oconee on similar waste. The polishing step of the distillate used ultrafiltration (UF) and reverse osmosis (RO) technology that was also used extensively by Ontario Hydro to assist in their processing of chemical cleaning solvent. This technology, equipment, and operations personnel were provided by Zenon Environmental, Inc. The concentrate from the evaporator was absorbed with a special open-quotes peat mossclose quotes based media that allowed it to be shipped and buried at the Environcare of Utah facility. This is the first time that this absorption media or burial site has been used for chemical cleaning solvent

  2. Chemical-Cleaning Demonstration Test No. 2 in a mock-up steam generator

    International Nuclear Information System (INIS)

    Jevec, J.M.; Leedy, W.S.

    1983-04-01

    This report describes the results of the mockup demonstration test of the first modified baseline process under Contract S-127, Chemical Cleaning of Nuclear Steam Generators. The objective of this program is to determine the feasibility of cleaning the secondary side of nuclear steam generators with state-of-the-art chemical cleaning technology. The first step was to benchmark a baseline process. This process was then modified to attempt to eliminate the causes of unacceptable cleaning performance. The modified baseline process consists of an EDTA/H 2 O 2 -based copper solvent and a near-neutral, EDTA/N 2 H 4 -based magnetite and crevice solvent. This report also presents the results of three inhibitor evaluation mockup runs used in the evaluation of the modified baseline process

  3. Evaluation of boiler chemical cleaning techniques

    International Nuclear Information System (INIS)

    1993-04-01

    The EPRI/SGOG process, which has been selected by Ontario Hydro for use at the Bruce A station, is described. This process consists of alternating iron removal and copper removal steps, the two metals which comprise the bulk of the deposit in the Bruce A SGs. The iron removal solvent consists of ethylenediameinetetraacetic acid (EDTA), hydrazine, ammonium hydroxide and a proprietary corrosion inhibitor CCI-801. The copper removal solvent consists of EDTA, ethylene diamine and hydrogen peroxide. Ontario Hydro proposes to clean a bank of four SGs in parallel employing a total of six copper removal steps and four iron removal steps. Cleaning all eight SGs in a single Bruce A unit will generate 2,200 m 3 of liquid waste which will be treated by a wet air oxidation process. The iron and copper sludges will be buried in a landfill site while the liquid waste will be further treated by the Bruce sewage treatment plant. Some ammonia vapour will be generated through the wet air oxidation process and will be vented through a stack on top of the high bay of the spent solvent treatment plant. With the exception of the proprietary corrosion inhibitor, all chemicals that will be employed in the cleaning and waste treatment operations are standard industrial chemicals which are well characterized. No extraordinary hazards are anticipated with their use as long as adequate safety precautions are taken

  4. Chemical cleaning the service water system at a nuclear power plant

    International Nuclear Information System (INIS)

    Brice, T.O.; Glover, W.A.

    1994-01-01

    Chemical cleaning a large cooling water system in a nuclear power plant presented many unique problems. The selection, qualification, and performance of the cleaning process were done using a phased approach. The piping was inspected to determine the extent of the problem. Deposit samples were removed from the service water system pipe and tested in the laboratory to determine the most effective cleaning solvent for deposit removal. An engineering study was performed to define the design parameters required to implement the system-wide chemical cleaning

  5. Corrosion Behavior of SA508 Coupled with and without Magnetite in Chemical Cleaning Environments

    International Nuclear Information System (INIS)

    Son, Yeong-Ho; Jeon, Soon-Hyeok; Song, Geun Dong; Hur, Do Haeng; Lee, Jong-Hyeon

    2017-01-01

    To mitigate these problems, chemical cleaning process has been widely used. However, the chemical cleaning solution can affect the corrosion of SG structural materials as well as the magnetite dissolution. During the chemical cleaning process, the galvanic corrosion between SG materials and magnetite is also anticipated because they are in electrical connection. However, the corrosion measurement or monitoring for the materials has been performed without consideration of galvanic effect coupled with magnetite during the chemical cleaning process. In this study, the effect of temperature and EDTA concentration on the corrosion behavior of SA508 tubesheet material with and without magnetite was studied in chemical cleaning solutions. The galvanic corrosion behavior between SA508 and magnetite is predicted by using the mixed potential theory and its effect on the corrosion rate of SA508 is also discussed. By newly designed immersion test, it was confirmed that the extent of galvanic corrosion effect between SA508 and magnetite increased with increasing temperature and EDTA concentration. The galvanic corrosion behavior of SA508 coupled with magnetite in chemical cleaning environments was predicted by the mixed potential theory and verified by ZRA and LP technique. Galvanic coupling increased the corrosion rate of SA508 due to the shift in its potential to the anodic direction. Therefore, the galvanic corrosion effect between SA508 and magnetite should be considered when the corrosion measurement is performed during the chemical cleaning process in steam generators.

  6. Service water chemical cleaning at River Bend gets results

    International Nuclear Information System (INIS)

    Brice, T.O.; Glover, W.A.

    1994-01-01

    The largest known Service Water System (SWS) chemical cleaning ever performed at a nuclear plant was successfully completed at, River Bend Station. Corrosion product buildup was observed during system inspections in the first operating cycle and the first refueling outage in 1987. Under deposit corrosion was followed with microbiologically influenced corrosion (MIC) occurring as a later stage under deposits. The heavy corrosion caused blockage of heat exchanger tubes, fouling of valve seats, and general flow blockage throughout the system. Various options were evaluated for restoring the SWS back to an acceptable long term operating condition. The large scale chemical cleaning performed arrested the corrosion by removing the deposits down to the bare metal surfaces and leaving behind a protective passivation layer. After the cleaning, the open recirculating SWS was converted to a closed system. The implementation of a molybdate/nitrate water treatment program with a copper corrosion inhibitor maintained at a high pH (8.5--10.5) has significantly reduced corrosion rates in the closed system. This should extend the life of the SWS piping for the remaining life of the plant. Several field tests were conducted to qualify the process and demonstrate its ability to achieve acceptable cleaning results prior to being used on a larger scale. In the summer of 1992, temporary and permanent modifications were installed to divide the SWS into two separate cleaning loops for the system wide cleaning. The SWS chemical was successfully performed and completed on schedule during the fourth refueling outage. Post cleaning inspections at various locations throughout the Service Water System showed the process to be very effective at complete deposit removal

  7. REVIEW OF ALTERNATIVE ENHANCED CHEMICAL CLEANING OPTIONS FOR SRS WASTE TANKS

    Energy Technology Data Exchange (ETDEWEB)

    Hay, M.; Koopman, D.

    2009-08-01

    A literature review was conducted to support the Task Technical and Quality Assurance Plan for Alternative Enhanced Chemical Cleaning (AECC) for sludge heel removal funded as part of the EM-21 Engineering and Technology program. The goal was to identify potential technologies or enhancements to the baseline oxalic acid cleaning process for chemically dissolving or mobilizing Savannah River Site (SRS) sludge heels. The issues with the potentially large volume of oxalate solids generated from the baseline process have driven an effort to find an improved or enhanced chemical cleaning technology for the tank heels. This literature review builds on a previous review conducted in 2003. A team was charged with evaluating the information in these reviews and developing recommendations of alternative technologies to pursue. The new information in this report supports the conclusion of the previous review that oxalic acid remains the chemical cleaning agent of choice for dissolving the metal oxides and hydroxides found in sludge heels in carbon steel tanks. The potential negative impact of large volumes of sodium oxalate on downstream processes indicates that the amount of oxalic acid used for chemical cleaning needs to be minimized as much as possible or the oxalic acid must be destroyed prior to pH adjustment in the receipt tank. The most straightforward way of minimizing the volume of oxalic acid needed for chemical cleaning is through more effective mechanical cleaning. Using a mineral acid to adjust the pH of the sludge prior to adding oxalic acid may also help to minimize the volume of oxalic acid used in chemical cleaning. If minimization of oxalic acid proves insufficient in reducing the volume of oxalate salts, several methods were found that could be used for oxalic acid destruction. For some waste tank heels, another acid or even caustic treatment (or pretreatment) might be more appropriate than the baseline oxalic acid cleaning process. Caustic treatment of high

  8. OXALATE MASS BALANCE DURING CHEMICAL CLEANING IN TANK 6F

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M.; Fink, S.

    2011-07-22

    The Savannah River Remediation (SRR) is preparing Tank 6F for closure. The first step in preparing the tank for closure is mechanical sludge removal. Following mechanical sludge removal, SRS performed chemical cleaning with oxalic acid to remove the sludge heel. Personnel are currently assessing the effectiveness of the chemical cleaning to determine whether the tank is ready for closure. SRR personnel collected liquid samples during chemical cleaning and submitted them to Savannah River National Laboratory (SRNL) for analysis. Following chemical cleaning, they collected a solid sample (also known as 'process sample') and submitted it to SRNL for analysis. The authors analyzed these samples to assess the effectiveness of the chemical cleaning process. Analysis of the anions showed the measured oxalate removed from Tank 6F to be approximately 50% of the amount added in the oxalic acid. To close the oxalate mass balance, the author collected solid samples, leached them with nitric acid, and measured the concentration of cations and anions in the leachate. Some conclusions from this work are: (1) Approximately 65% of the oxalate added as oxalic acid was removed with the decanted liquid. (2) Approximately 1% of the oxalate (added to the tank as oxalic acid) formed precipitates with compounds such as nickel, manganese, sodium, and iron (II), and was dissolved with nitric acid. (3) As much as 30% of the oxalate may have decomposed forming carbon dioxide. The balance does not fully account for all the oxalate added. The offset represents the combined uncertainty in the analyses and sampling.

  9. Chemical cleaning of Dresden Unit 1: Final report

    International Nuclear Information System (INIS)

    1986-05-01

    The introduction of NS-1 solvent into the full primary system of Dresden Unit-1 nuclear power reactor on September 12, 1984, represented the culmination of several years of development, testing, planning, and construction. The requirement was to dissolve the highly radioactive deposits of primarily nickel ferrite without any corrosion which might compromise the reactor systems. During the actual cleaning with the NS-1 solvent, the chemical condition of the circulating solvent was measured. Iron, nickel, and radioactive cobalt all dissolved smoothly. The amount of copper in solution decreased in concentration, verifying expectations that metallic copper would plate on to clean metal surfaces. A special rinse formulation was employed after the primary cleaning steps and the ''lost'' copper was thus redissolved and removed from the system. After the cleaning was complete and the reactor had been refilled with pure water, radiation levels were measured. The most accurate of these measurements gave decontamination factors ranging well above 100, which indicated a significant removal of the radioactive deposits, and demonstrated the success of this project. Treatment of the radioactive liquid wastes from this operation required volume reduction and water purification. The primary method of processing the spent cleaning solvent and rinse water was evaporation. The resulting concentrate has been stored as a liquid, awaiting solidification to allow burial at a designated site. Water which was separated during evaporation, along with the dilute rinses, was processed by various chemical means, reevaporated, treated with activated carbon, and/or demineralized before its radionuclide and chemical content was low enough to allow it to be returned to Dresden Station for treatment or disposal. 60 figs., 31 tabs

  10. Qualification test of chemical cleaning for secondary side of steam generator in Qinshan Nuclear Power Plant

    International Nuclear Information System (INIS)

    Zhang Mengqin; Zhang Shufeng; Yu Jinghua; Hou Shufeng

    1997-07-01

    The chemical cleaning technique for removing sludge on the secondary side in Qinshan Nuclear Power Plant has been qualified. The chemical cleaning process will carry out during shutdown refuelling. The qualification test has studied the effect of chemical cleaning agent component, cleaning time on dissolution effectiveness of sludge (Fe 3 O 4 ) and to evaluate corrosion situation of main materials of SG in the cleaning process. The main component of cleaning agent is EDTA. The cleaning temperature is 20∼30 degree C. It is determined that allowable remains amount of cleaning agent (EDTA). The technique of cleaning, rinse, passivation for the chemical cleaning in Qinshan Nuclear Power Plant has been made. The qualification test shown that the technique can dissolve Fe 3 O 4 >1 g/L, the corrosion of materials is in allowable value, the allowable remains of EDTA is <0.01%. The technique character is static, ambient temperature. (9 refs., 12 tabs.)

  11. Chemical cleaning of the Bruce A steam generators

    International Nuclear Information System (INIS)

    Le Surf, J.E.; Mason, J.B.; Symmons, W.R.; Yee, F.

    1992-01-01

    Deposits consisting mostly of oxides and salts and copper metal in the secondary side of the steam generators at the Bruce A Nuclear Generating Station have caused instability in the steam flow and loss of heat capacity, resulting in derating of the units and reduction in power production. Attempts to remove the deposits by pressure pulsing were unsuccessful. Water lancing succeeded in restoring stability, but restrictions on access prevented complete lancing of the tube support plate holes. Chemical cleaning using a modified EPRI-SGOG process has been selected as the best method of removing the deposits. A complete chemical cleaning system has been designed and fabricated for Ontario Hydro by Pacific Nuclear, with support from AECL CANDU and their suppliers. The system consists of self contained modules which are easily interconnected on site. The whole process is controlled from the Control Module, where all parameters are monitored on a computer video screen. The operator can control motorized valves, pumps and heaters from the computer key board. This system incorporates all the advanced technologies and design features that have been developed by Pacific Nuclear in the design, fabrication and operation of many systems for chemical decontamination and cleaning of nuclear systems. 2 figs

  12. Chemical cleaning specification: few tube test model

    International Nuclear Information System (INIS)

    Hampton, L.V.; Simpson, J.L.

    1979-09-01

    The specification is for the waterside chemical cleaning of the 2 1/4 Cr - 1 Mo steel steam generator tubes. It describes the reagents and conditions for post-chemical cleaning passivation of the evaporator tubes

  13. Steam Generator Chemical Cleaning Application: Korean Experience in PWR NPP

    International Nuclear Information System (INIS)

    Hwang, In-Ho; Varrin-Jr, Robert-D.; Little, Michael-J.; Oh, Yeon-Ok; Choo, Seong-Jib; Park, Jin-Hyeok

    2012-09-01

    Korea Hydro and Nuclear Power (KHNP) performed an EPRI/SGOG chemical cleaning of the secondary side of the steam generators at Ulchin Unit 3 (UCN3) in March 2011 and at Ulchin Unit 4 (UCN4) in September 2011. The steam generator chemical cleaning (SGCC) was performed with venting at the top-of-tube sheet (TTS) and at tube support plates (TSPs) 4, 5, 6, 7, 8, 9, and 10. A primary objective of this SGCC was to address outer diameter stress corrosion cracking (ODSCC), which has been observed at the TTS and TSPs in the UCN3 SGs. The EPRI/SGOG process has been shown to effectively reduce prevailing ODSCC rates at the TTS and TSPs, particularly when applied with periodic venting in this application. This was the first full-length SGCC campaign with venting performed in Korea. Ulchin Unit 3 commenced commercial operation in August 1998 and Ulchin Unit 4 commenced commercial operation in December 1999. UCN3 and UCN4 are a two-loop pressurized water reactor (PWR) of the Korea Standard Nuclear Plant (KSNP) design. The SGs contain high-temperature mill annealed (HTMA) Alloy 600 tubing and are similar in design to the Combustion Engineering CE-80. The KSNP SGs have been susceptible to outer diameter stress corrosion cracking (ODSCC), which is consistent with operating experience for other SGs containing Alloy 600HTMA tubing material. The UCN3/4 SGs have recently begun to experience ODSCC. Hankook Jungsoo Industries Co., Ltd (HaJI) was selected as the cleaning vendor by KHNP. To date, HaJI has completed five Advanced Scale Conditioning Agent (ASCA) cleaning applications and two EPRI/SGOG Steam Generator Chemical Cleaning (SGCC) campaigns for KHNP. The goal of total deposit removal of the applications were successfully achieved and the amounts are 3,579 kg at UCN3 and 3,786 kg at UCN4 which values were estimated before each cleaning by analysing ECT signal and liquid samples from the SGs. The deposits from the SGs were primarily composed of magnetite. There were no chemical

  14. Steam generator chemical cleaning demonstration test No. 1 in a pot boiler

    International Nuclear Information System (INIS)

    Key, G.L.; Helyer, M.H.

    1981-04-01

    The effectiveness of the Electric Power Research Institute (EPRI Mark I) chemical cleaning solvent process was tested utilizing a 12 tube pot boiler that had previously been fouled and dented under 30 days of high chloride fault chemistry operation. Specifically, the intent of this chemical cleaning test was to: (1) dissolve sludge from the tubesheet, (2) remove non-protective magnetite from dented tube/support crevice regions, and (3) quantify the extent of corrosion of steam generator material during the test. Two laboratory cleaning demonstrations of 191 and 142 hours were performed

  15. Influence of wet chemical cleaning on quantum efficiency of GaN photocathode

    International Nuclear Information System (INIS)

    Wang Xiao-Hui; Gao Pin; Wang Hong-Gang; Li Biao; Chang Ben-Kang

    2013-01-01

    GaN samples 1–3 are cleaned by a 2:2:1 solution of sulfuric acid (98%) to hydrogen peroxide (30%) to de-ionized water; hydrochloric acid (37%); or a 4:1 solution of sulfuric acid (98%) to hydrogen peroxide (30%). The samples are activated by Cs/O after the same annealing process. X-ray photoelectron spectroscopy after the different ways of wet chemical cleaning shows: sample 1 has the largest proportion of Ga, N, and O among the three samples, while its C content is the lowest. After activation the quantum efficiency curves show sample 1 has the best photocathode performance. We think the wet chemical cleaning method is a process which will mainly remove C contamination. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  16. Chemical cleaning as an essential part of steam generator asset management

    International Nuclear Information System (INIS)

    Stiepani, C.; Ammann, F.; Jones, D.; Evans, S.; Harper, K.

    2010-01-01

    Accumulation of deposits is intrinsic for the operation of Steam Generators in PWRs. Such depositions often lead to reduction of thermal performance, loss of component integrity and, in some cases to power restrictions. Accordingly removal of such deposits is an essential part of the asset management of the Steam Generators in a Nuclear Power Plant. Every plant has its individual condition, history and constraints which need to be considered when planning and performing a chemical cleaning. Typical points are: Sludge load amount and constitution of the deposits; Sludge distribution in the steam generator; Existing or expected corrosion problems; Amount and treatment possibilities for the waste generated. Depending on these points the strategy for chemical cleaning shall be evolved. The range of treatment starts with very soft cleanings with a removal of approx 100 kg per steam generator and goes to a full scale cleaning which can remove up to several thousand kilograms of deposits from a steam generator. Depending on the goal to be achieved and the steam generator present an adequate cleaning method shall be selected. Flexible and 'customizable' cleaning methods that can be adapted to the individual needs of a plant are therefore a must. Particular for the application of preventive cleanings where repeated or even regular application are intended, special focus has to be put on low corrosion and easy waste handling. Therefore AREVA has developed the 'C3' concept, Customized Chemical Cleaning concept. This concept covers the entire range of steam generator cleaning. Particular for the preventive maintenance cleanings processes with extreme low corrosion rates and easy waste handling are provided which make repeated applications safe and cost efficient. (author)

  17. Chemical cleaning - essential for optimal steam generator asset management

    International Nuclear Information System (INIS)

    Ammann, Franz

    2009-01-01

    Accumulation of deposits in Steam Generator is intrinsic during the operation of Pressurized Water Reactors. Such depositions lead to reduction of thermal performance, loss of component integrity and, in some cases, to power restrictions. Accordingly, removal of such deposits is an essential part of the asset management program of Steam Generators. Every plant has specific conditions, history and constraints which must be considered when planning and performing a chemical cleaning. Typical points are: -Constitution of the deposits or sludge - Sludge load - Sludge distribution in the steam generator - Existing or expected corrosion problems - Amount and tendency of fouling for waste treatment The strategy for chemical cleaning is developed from these points. The range of chemical cleaning treatments starts with very soft cleanings which can remove approximately 100kg per steam generator and ends with full scale, i.e., hard, cleanings which can remove several thousand kilograms of deposits from a steam generator. Dependent upon the desired goal for the operating plant and the steam generator material condition, the correct cleaning method can be selected. This requires flexible cleaning methods that can be adapted to the individual needs of a plant. Such customizing of chemical cleaning methods is a crucial factor for an optimized asset management program of steam generators in a nuclear power plant

  18. Chemical cleaning of steam generators: application to Nogent 1

    International Nuclear Information System (INIS)

    Fiquet, J.M.; Veysset, J.P.; Esteban, L.; Saurin, P.

    1991-01-01

    EDF has patented a chemical cleaning process for PWR steam generators, based on the use of a mixture or organic acids in order to dissolve iron oxides and copper with a single solution and clean dented crevices. Qualification tests have permitted to demonstrate effectiveness of the solution and its innocuousness related to steam generator materials. The process, the licence of which belongs to SOMAFER RA and Framatome has been implemented in France at Nogent. The goal was to dissolve iron oxides allowing metallic particles, aggregated on the tubesheet, to be released and mechanically removed. The effectiveness was satisfactory and this treatment is to be extended to other units. (author)

  19. Tank 12H Acidic Chemical Cleaning Sample Analysis And Material Balance

    International Nuclear Information System (INIS)

    Martino, C. J.; Reboul, S. H.; Wiersma, B. J.; Coleman, C. J.

    2013-01-01

    A process of Bulk Oxalic Acid (BOA) chemical cleaning was performed for Tank 12H during June and July of 2013 to remove all or a portion of the approximately 4400 gallon sludge heel. Three strikes of oxalic acid (nominally 4 wt % or 2 wt %) were used at 55 deg C and tank volumes of 96- to 140-thousand gallons. This report details the sample analysis of a scrape sample taken prior to BOA cleaning and dip samples taken during BOA cleaning. It also documents a rudimentary material balance for the Tank 12H cleaning results

  20. Development of clean chemical mechanical polishing systems; Clean CMP system

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimura, M.; Hosokawa, M. [Ebara Corp., Tokyo (Japan)

    1998-10-20

    Described herein are clean chemical mechanical polishing (CMP) systems developed by Ebara. A CMP system needs advanced peripheral techniques, in addition to those for grinding adopted by the conventional system, in order to fully exhibit its inherent functions. An integrated design concept is essential for the CMP steps, including slurry supplying, polishing, washing, process controlling and waste fluid treatment. The Ebara has adopted a standard concept `Clean CMP, dry-in and dry-out of wafers,` and provided world`s highest grades of techniques for inter-layer insulating film, shallow trench isolation, plug and wiring. The head for the polishing module is specially designed by FEM, to improve homogeneity of wafers from the center to edges. The dresser is also specially designed, to improve pad surface topolody after dressing. A slurry dipsersing method is developed to reduce slurry consumption. Various washing modules, designed to have the same external shape, can be allocated to various functions. 10 figs.

  1. CHEMICAL AND ENERGETIC CONTENT OF CORN BEFORE AND AFTER PRE-CLEANING

    Directory of Open Access Journals (Sweden)

    Sandra Iara Furtado Costa Rodrigues

    2015-04-01

    Full Text Available The poultry industry normally has little control over the raw material that arrives at the processing plant. This experiment aimed to evaluate chemical and energetic quality of corn obtained in a feed mill before and after pre-cleaning. Twenty samples of 30 kg of corn each were taken from trucks delivering corn to the mill. The trucks were then unloaded and the material passed through a pre-cleaning process when another sample was taken. Samples were graded and physical properties evaluated: density (g/L, grain percentages of foreign material, impurities, fragments, broken, soft, insect damaged, fire-burnt, fermented, damaged, cracked and fine particles, as well as chemical composition analysis: Apparent metabolizable energy for poultry (AME, ether extract (EE, crude fiber (CF, starch (STA, water activity (WA, crude protein (CP, digestible and total lysine, methionine, cystine, threonine, tryptophan, valine, isoleucine, leucine, phenylalanine, histidine and arginine. The experiment was a randomized design with two treatments (before and after pre-cleaning and twenty replications. Data was analyzed using SAS ® and treatment differences obtained using F test. Correlations and principal components were calculated. There was a decrease in density after the pre-cleaning process, which was probably due to the removal of earth and stones rather than grain and its fractions. Significant increases were found for insect damage, fermented and damaged grain while fire-burn was significantly reduced after the pre-cleaning process. Starch increased after pre-cleaning which is a result of contaminants that normally are poor in this carbohydrate, but fiber levels increased too. Apparent metabolizable energy, aminoacids, digestible (P<0.05 and total (P<0.05 histidine, total lysine and methionine (P<0.1 levels were reduced after pre-cleaning. Density was higher when there were fewer impurities such as straw, husk or small grains. Broken corn was positively

  2. Aquaporin based biomimetic membrane in forward osmosis: Chemical cleaning resistance and practical operation

    KAUST Repository

    Li, Zhenyu

    2017-07-27

    Aquaporin plays a promising role in fabricating high performance biomimetic forward osmosis (FO) membranes. However, aquaporin as a protein also has a risk of denaturation caused by various chemicals, resulting in a possible decay of membrane performance. The present study tested a novel aquaporin based biomimetic membrane in simulated membrane cleaning processes. The effects of cleaning agents on water flux and salt rejection were evaluated. The membrane showed a good resistance to the chemical agents. The water flux after chemical cleaning showed significant increases, particularly after cleaning with NaOCl and Alconox. Changes in the membrane structure and increased hydrophilicity in the surrounding areas of the aquaporin may be accountable for the increase in water permeability. The membrane shows stable salt rejection up to 99% after all cleaning agents were tested. A 15-day experiment with secondary wastewater effluent as the feed solution and seawater as the draw solution showed a stable flux and high salt rejection. The average rejection of the dissolved organic carbon from wastewater after the 15-day test was 90%. The results demonstrated that the aquaporin based biomimetic FO membrane exhibits chemical resistance for most agents used in membrane cleaning procedures, maintaining a stable flux and high salt rejection.

  3. Aquaporin based biomimetic membrane in forward osmosis: Chemical cleaning resistance and practical operation

    KAUST Repository

    Li, Zhenyu; Valladares Linares, Rodrigo; Bucs, Szilard; Fortunato, Luca; Hé lix-Nielsen, Claus; Vrouwenvelder, Johannes S.; Ghaffour, NorEddine; Leiknes, TorOve; Amy, Gary

    2017-01-01

    Aquaporin plays a promising role in fabricating high performance biomimetic forward osmosis (FO) membranes. However, aquaporin as a protein also has a risk of denaturation caused by various chemicals, resulting in a possible decay of membrane performance. The present study tested a novel aquaporin based biomimetic membrane in simulated membrane cleaning processes. The effects of cleaning agents on water flux and salt rejection were evaluated. The membrane showed a good resistance to the chemical agents. The water flux after chemical cleaning showed significant increases, particularly after cleaning with NaOCl and Alconox. Changes in the membrane structure and increased hydrophilicity in the surrounding areas of the aquaporin may be accountable for the increase in water permeability. The membrane shows stable salt rejection up to 99% after all cleaning agents were tested. A 15-day experiment with secondary wastewater effluent as the feed solution and seawater as the draw solution showed a stable flux and high salt rejection. The average rejection of the dissolved organic carbon from wastewater after the 15-day test was 90%. The results demonstrated that the aquaporin based biomimetic FO membrane exhibits chemical resistance for most agents used in membrane cleaning procedures, maintaining a stable flux and high salt rejection.

  4. The AREVA customized chemical cleaning C3-concept as part of the steam generator asset management

    International Nuclear Information System (INIS)

    Weiss, Steffen; Drexler, Andreas

    2012-09-01

    In pressurized water reactors corrosion products and impurities are transported into the steam generators by feed water. Corrosion products and impurities are accumulated in the SGs as deposits and scales on the tubes, the tube support structures and the tube sheet. Depending on the location, the composition and the morphology such deposits may negatively affect the performance of the steam generators by reducing the thermal performance, changing the flow patterns and producing localized corrosion promoting conditions. Accordingly removal of deposits or deposit minimization strategies are an essential part of the asset management program of the steam generators in Nuclear Power Plants. It is evident that such a program is plant specific, depending on the individual condition prevailing. Parameters to be considered are for example: - Steam generator and balance of plant design; - Secondary side water chemistry treatment; - Deposit amount and constitution; - Deposit distribution in the steam generator; - Existing or expected corrosion problems. After evaluation of the steam generator condition a strategy for deposit minimization has to be developed. Depending on the individual situation such strategies may span from curative full scale cleanings which are capable of removing the entire sludge inventory in the range of several 1000 kg per SG to preventive cleanings that remove only a portion of the deposits in the range of several 100 kg per SG. But also other goals depending on the specific plant situation, like tube sheet sludge piles or hard scale removal, may be considered. Beside the chemical cleaning process itself also the integration of the process into the outage schedule and considerations about its impact on other maintenance activities is of great importance. It is obvious that all these requirements cannot be met easily by a standardized cleaning method, thus a customisable chemical cleaning technology is required. Based on its comprehensive experience

  5. Effect of Time in Chemical Cleaning of Ultrafiltration Membranes

    NARCIS (Netherlands)

    Levitsky, I.; Naim, R.; Duek, A.; Gitis, V.

    2012-01-01

    Chemical cleaning of ultrafiltration membranes is often considered successful when the flux through a cleaned membrane is much higher than through a pristine one. Here, a novel definition of cleaning intensity is proposed as the product of the concentration of the cleaning agent and the cleaning

  6. Corrosion monitoring during a chemical cleaning

    International Nuclear Information System (INIS)

    Delepine, J.; Feron, D.; Roy, M.

    1994-01-01

    In order to estimate the possible corrosion induced by the chemical cleaning, a corrosion monitoring has been realized during the cleaning of the secondary circuit (including the model boiler) of ORION loop. It included coupons and electrodes and has required a preliminary setting in laboratory. The electrochemical device which was used during the chemical cleaning included two reference electrodes (Ag/AgCl) and eight metallic electrodes (carbon steel, stainless steel, Alloy 600 and Alloy 690) for free corrosion potential monitoring, three other carbon steel electrodes for instantaneous corrosion rate measurements by polarization resistance and three coupling devices with different surface ratios between carbon steel and Alloy 600. The results showed a good agreement between corrosion rates measured by weight losses on coupons or by electrochemistry (polarization resistance), and an increase of the carbon steel corrosion rate when it was coupled with Alloy 600. (authors). 5 figs., 2 tabs., 3 refs

  7. The impact of chemical cleaning on separation efficiency and properties of reverse osmosis membrane

    KAUST Repository

    Baatiyyah, Hani

    2018-04-01

    One of most major concerns from both cost-effective and technical point of view in membrane process industry is membrane cleaning. The aim of the project was to investigate the variations in membrane surface properties and separation efficiency of reverse osmosis membrane. Compativtive analysis have to be performed on four RO membrane before and after exposing the virgin membrane into chemical cleaning to identify and analysis the impact of the chemical cleaning on the performance of RO membrane. Commerical chemical cleaning used in this project were caustic and acidic cleaning agent. The project’s aim is the investigation of simulation software’s precision for the four membranes performance projection at different conditions of the feed water. The assessment of the membranes performance was done in the Innovation Cluster at pilot plant that was industrial in size. The main commercial elements used were the thin-film composite membranes with a spiral-wound of 8-inch polyamide. Ultrafiltration (UF) and seawater RO membrane pretreatment process was done for the red sea sourced feed water. A pressure vessel dimensioned at 8-inch was operated in conjunction with an individual element at 8 -20 m3/hr feed flow rate, with an 8 to 12 % recovery and an average 35,000-42,000 mg/L of total dissolved solids (TDS) composition for the feed water. To achieve the project’s aim in assessing the membranes, three phase experimental stages were completed. The membranes performance was assessed in terms of their water flux, salt rejection, boron rejection, bicarbonate rejection and permeate quality. In addition, the membrane surfaces were characterized after exposing the fresh membranes with a chemical cleaning reagent. The experimental results showed an increase in both permeate flow and salt passage for all studied elements. The changes in the membranes performance were systematically explained based on the changes in the charge density and chemical structure of the membranes

  8. Chemical cleaning of UK AGR boilers

    International Nuclear Information System (INIS)

    Rudge, A.; Turner, P.; Ghosh, S.; Clary, W.; Tice, D.R.

    2002-01-01

    For a number of years, the waterside pressure drops across the advanced gas-cooled reactor (AGR) pod boilers have been increasing. The pressure drop increases have accelerated with time, which is the converse behaviour to that expected for rippled magnetite formation (rapid initial increase slowing down with time). Nonetheless, magnetite deposition remains the most likely cause for the increasing boiler resistances. A number of potential countermeasures have been considered in response to the boiler pressure drop increases. However, there was no detectable reduction in the rate of pressure drop increase. Chemical cleaning was therefore considered and a project to substantiate and then implement chemical cleaning was initiated. (authors)

  9. Effectuality of Cleaning Workers' Training and Cleaning Enterprises' Chemical Health Hazard Risk Profiling.

    Science.gov (United States)

    Suleiman, Abdulqadir M; Svendsen, Kristin V H

    2015-12-01

    Goal-oriented communication of risk of hazards is necessary in order to reduce risk of workers' exposure to chemicals. Adequate training of workers and enterprise priority setting are essential elements. Cleaning enterprises have many challenges and the existing paradigms influence the risk levels of these enterprises. Information on organization and enterprises' prioritization in training programs was gathered from cleaning enterprises. A measure of enterprises' conceptual level of importance of chemical health hazards and a model for working out the risk index (RI) indicating enterprises' conceptual risk level was established and used to categorize the enterprises. In 72.3% of cases, training takes place concurrently with task performances and in 67.4% experienced workers conduct the trainings. There is disparity between employers' opinion on competence level of the workers and reality. Lower conceptual level of importance was observed for cleaning enterprises of different sizes compared with regional safety delegates and occupational hygienists. Risk index values show no difference in risk level between small and large enterprises. Training of cleaning workers lacks the prerequisite for suitability and effectiveness to counter risks of chemical health hazards. There is dereliction of duty by management in the sector resulting in a lack of competence among the cleaning workers. Instituting acceptable easily attainable safety competence level for cleaners will conduce to risk reduction, and enforcement of attainment of the competence level would be a positive step.

  10. Chemical cleaning of PWR steam generators: application at Nogent 1

    International Nuclear Information System (INIS)

    Fiquet, J.M.; Veysset, J.P.; Esteban, L.; Saurin, P.

    1990-01-01

    EDF has developed and patented a chemical cleaning process for PWR steam generators, based on the use of a mixture of organic acids in order to: - dissolve iron oxides and copper with a single solution; - clean dented crevices. Qualification tests have permitted to demonstrate effectiveness of the solution and its inocuousness related to steam generator materials. The process, the license of which belongs to SOMAFER R.A. and FRAMATOME, has been implemented in France at Nogent. The goal was to dissolve iron oxides allowing metallic particles, aggregated on the tubesheet, to be released and mechanically removed. The effectiveness was satisfactory and this treatment is to be extended to other units [fr

  11. Steam generator secondary side chemical cleaning at Gentilly-2

    International Nuclear Information System (INIS)

    Plante, S.

    2006-01-01

    After more than 20 years of operation, the secondary side of the four steam generators at Gentilly-2 were chemically cleaned during the 2005 annual outage. The FRAMATOME ANP high temperature cleaning process used to remove magnetite loading involved stepwise injection of solvent with PHT temperature in the range 160 o C to 175 o C. The heat required to maintain the PHT temperature was provided by the operation of the main PHT pumps and the reactor core residual heat. The temperature control was accomplished by the shutdown cooling system heat exchangers. A total of 1280 kg of magnetite was removed from the four steam generators. A copper-cleaning step was applied after the iron step. The PHT has been cooled down and the steam generators drained to temporary tanks and dried in preparation of the copper step. The process has been applied at room temperature, two boilers at a time. The solvent removed a total of 116 kg of copper. During the iron step, steam flow to the feedwater tank chemically contaminate the Balance Of Plant (BOP) systems. The isolation of this path should have been part of the G2 procedures. Around 700 m3 of water had to be drained to interim storage tanks for subsequent resin treatment before disposal. Visual inspection of BO1 tubesheet and first support plate showed clean surfaces without measurable sludge pile. Upper support plates visual inspection of BO4 revealed that broach holes blockage reported in 2000 is still present in peripheral area. Following the plant restart, the medium range level measurement instability observed since several years for BO3 was no more present. As anticipated, it also has been observed that the medium and wide range level measurements have shifted down as a result of downcomer flow increase after the cleaning. The cleaning objectives were achieved regarding the fouling reduction on the steam generators secondary side but broach holes blockage of the upper support plate is still present in periphery. (author)

  12. Processing method for chemical cleaning liquid on the secondary side of steam generator

    International Nuclear Information System (INIS)

    Nishihara, Yukio; Inagaki, Yuzo.

    1993-01-01

    Upon processing nitrilotriacetate (NTA), Fe liquid wastes mainly comprising Fe and Cu liquid wastes mainly comprising ethylene diamine and Cu generated upon chemical cleaning on the secondary side of a steam generator, pH of the Fe liquid wastes is lowered to deposit and separate NTA. Then, Fe ions in a filtrates are deposited on a cathode by electrolysis, as well as remaining NTA is decomposed by oxidation at an anode by O 2 gas. Cu liquid wastes are reacted with naphthalene disulfate and Ba ions and the reaction products are separated by deposition as sludges. Remaining Cu ions in the filtrates are deposited on the cathode by electrolysis. With such procedures, concentration of COD(NTA), Fe ions and Cu ions can greatly be reduced. Further, since capacity of the device can easily be increased in this method, a great amount of liquid wastes can be processed in a relatively short period of time. (T.M.)

  13. Chemical cleaning an essential part of steam generator asset management

    International Nuclear Information System (INIS)

    Amman, Franz

    2008-01-01

    Chemical Cleaning an essential part of Steam Generator asset management accumulation of deposits is intrinsic for the operation of Steam Generators in PWRs. Such depositions often lead to reduction of thermal performance, loss of component integrity and, in some cases to power restrictions. Accordingly removal of such deposits is an essential part of the asset management of the Steam Generators in a Nuclear Power Plant. Every plant has its individual condition, history and constraints which need to be considered when planning and performing a chemical cleaning. Typical points are: - Sludge load amount and constitution of the deposits - Sludge distribution in the steam generator - Existing or expected corrosion problems - Amount and tendency of fouling for waste treatment Depending on this points the strategy for chemical cleaning shall be evolved. the range of treatment starts with very soft cleanings with a removal of approx 100 kg per steam generator and goes to a full scale cleaning which can remove up to several thousand kilograms of deposits from a steam generator. Depending on the goal to be achieved and the steam generator present an adequate cleaning method shall be selected. This requires flexible and 'customisable' cleaning methods that can be adapted to the individual needs of a plant. Such customizing of chemical cleaning methods is an essential factor for an optimized asset management of the steam generator in a nuclear power plant

  14. Chemical cleaning/disinfection and ageing of organic UF membranes: a review.

    Science.gov (United States)

    Regula, C; Carretier, E; Wyart, Y; Gésan-Guiziou, G; Vincent, A; Boudot, D; Moulin, P

    2014-06-01

    Membrane separation processes have become a basic unit operation for process design and product development. These processes are used in a variety of separation and concentration steps, but in all cases, the membranes must be cleaned regularly to remove both organic and inorganic material deposited on the surface and/or into the membrane bulk. Cleaning/disinfection is a vital step in maintaining the permeability and selectivity of the membrane in order to get the plant to its original capacity, to minimize risks of bacteriological contamination, and to make acceptable products. For this purpose, a large number of chemical cleaning/disinfection agents are commercially available. In general, these cleaning/disinfection agents have to improve the membrane flux to a certain extent. However, they can also cause irreversible damages in membrane properties and performances over the long term. Until now, there is considerably less literature dedicated to membrane ageing than to cleaning/disinfection. The knowledge in cleaning/disinfection efficiency has recently been improved. But in order to develop optimized cleaning/disinfection protocols there still remains a challenge to better understand membrane ageing. In order to compensate for the lack of correlated cleaning/disinfection and ageing data from the literature, this paper investigates cleaning/disinfection efficiencies and ageing damages of organic ultrafiltration membranes. The final aim is to provide less detrimental cleaning/disinfection procedures and to propose some guidelines which should have been taken into consideration in term of membrane ageing studies. To carry out this study, this article will detail the background of cleaning/disinfection and aging membrane topics in a first introductive part. In a second part, key factors and endpoints of cleaning/disinfection and aging membranes will be discussed deeply: the membrane role and the cleaning parameters roles, such as water quality, storing conditions

  15. Development of chemical cleaning formulation for service water system of FBTR

    International Nuclear Information System (INIS)

    Velmurugan, S.; Narasimhan, S.V.; Das, P.C.; Mathur, P.K.

    1995-01-01

    Service water system of Fast Breeder Test Reactor (FBTR) was found to be corroded and at few locations, the corrosion product oxides were choking the smaller diameter pipelines. An attempt was made to develop a chemical cleaning formulation to chemically remove the oxides using a surface conditioner and chelating agents. Of the several complexants tested, hydroxyethylethylene diamine tetraacetic acid (HEDTA) was found to be better than other complexants from the point of view of oxide dissolution efficiency, solubility etc. A two stage chemical cleaning process involving conditioning of the oxide layer with 0.1% tannic acid followed by exposure of the conditioned oxide layer with a formulation containing 1% HEDTA + 0.5% Sodium Gluconate +0.2% hexamine was recommended to remove the corrosion product oxide present in the service water system. (author). 4 refs., 2 tabs

  16. EM-31 Alternative and Enhanced Chemical Cleaning Program

    International Nuclear Information System (INIS)

    King, Bill

    2010-01-01

    King's introduction to his presentation made 5 important points: (1) Numerous SRS tanks scheduled for closure (contract commitments); (2) Cannot remove all sludge by mechanical means due to obstructions; (3) Chemical removal technology needed (likely oxalic acid); (4) Post - dissolution neutralization required prior to transfer to compliant tanks; (5) Sodium oxalate salts precipitate on neutralization and have negative downstream impacts. There were three SRS chemical cleaning programs in 2010: Baseline: 8wt percent OA batch contact, ECC: 1-3 wt. percent OA with oxalate destruction, and the Alternative/Enhanced Chemical Cleaning (EM-31). This talk is on the EM-31 program.

  17. Carbon steel corrosion prevention during chemical cleaning of steam generator secondary side components

    International Nuclear Information System (INIS)

    Fulger, M.; Lucan, D.; Velciu, L.

    2009-01-01

    During operation of a nuclear power plant, many contaminants, such as solid particles or dissolved species are formed in the secondary circuit, go into steam generator and deposit as scales on heat transfer tubing, support plate or as sludge on tube sheet. By accumulation of these impurities, heat transfer is reduced and the integrity of the steam generator tubing is influenced. Chemical cleaning is a qualified, efficient measure to improve steam generator corrosion performance. The corrosion mechanism can be counteracted by the chemical cleaning of the deposits on the tube sheet and the scales on the heat transfer tubing. The major component of the scales is magnetite, which can be dissolved using an organic chelating agent (ethylenediaminetetraacetic acid, EDTA) in combination with a complexing agent such as citric acid in an alkaline reducing environment. As the secondary side of SG is a conglomerate of alloys it is necessary to choose an optimal chemical cleaning solution for an efficient cleaning properties and at the same time with capability of corrosion prevention of carbon steel components during the process. The paper presents laboratory tests initiated to confirm the ability of this process to clean the SG components. The experiments followed two paths: - first, carbon steel samples have been autoclavized in specific secondary circuit solutions of steam generator to simulate the deposits constituted during operation of this equipment; - secondly, autoclavized samples have been cleaned with a solvent composed of EDTA citric acid, hydrazine of pH = 5 and temperature of 85 deg. C. Before chemical cleaning, the oxide films were characterized by surface analysis techniques including optical microscopy, scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). Applied to dissolve corrosion products formed in a steam generator, the solvents based on chelating agents are aggressive toward carbon steels and corrosion inhibitors are

  18. Enhanced Chemical Cleaning: Effectiveness Of The UV Lamp To Decompose Oxalates

    International Nuclear Information System (INIS)

    Ketusky, E.; Huff, T.; Sudduth, C.

    2010-01-01

    Enhanced Chemical Cleaning is a new process scheduled to begin cleaning Savannah River Site High Level Waste Tanks in 2012. It is an improvement over the current chemical cleaning method, in that it minimizes downstream impacts on the High Level Waste System. It is based on a state of the art scale removal process used on the secondary side of nuclear power plants, with modifications to accommodate the unique constraints created by the tanks. Both Enhanced Chemical Cleaning and the scale removal process are founded on dissolving metal oxides/hydroxides using oxalic acid, with subsequent oxalate decomposition via hydroxylation using ozone or peroxide, and UV light as a catalyst. A divergence Enhanced Chemical Cleaning has from nuclear power scale removal is the significantly increased solids concentration during oxalate decomposition. These solids can limit the ability of the UV light to create hydroxyl radicals, either by limiting the ability of the light to penetrate through the solution, or by increasing the fouling rate on the UV light. Both will decrease the overall catalytic effectiveness, thereby decreasing the concentration of formed hydroxyl radicals. The hydroxyl radicals are the driving force behind the oxalate decomposition. To understand the impact of increased solids, testing was performed using a medium pressure UV light inside an ozone supplied Oxalate Decomposition Reactor. Using a dissolved metal sludge simulant with an initial oxalate concentration greater than 12,000 ppm, and an initial pH of about 2.0, the spent acid solution was recirculated through the reactor, while the UV light was allowed to foul. For the first few hours, the oxalate decomposition rate was about 1,300 ppm/hour. After about 3 hours, enough time for the UV lamp to foul, the oxalate decomposition rate decreased to about 500 ppm/hour. The decomposition rate then remained roughly constant for the next 16 hours. Overall, testing showed that the oxalate destruction rate decreased

  19. Innovative technologies on fuel assemblies cleaning for sodium fast reactors: First considerations on cleaning process

    International Nuclear Information System (INIS)

    Simon, N.; Lorcet, H.; Beauchamp, F.; Guigues, E.; Lovera, P.; Fleche, J. L.; Lacroix, M.; Carra, O.; Dechelette, F.; Prele, G.; Rodriguez, G.

    2012-01-01

    Within the framework of Sodium Fast Reactor development, innovative fuel assembly cleaning operations are investigated to meet the GEN IV goals of safety and of process development. One of the challenges is to mitigate the Sodium Water Reaction currently used in these processes. The potential applications of aqueous solutions of mineral salts (including the possibility of using redox chemical reactions) to mitigate the Sodium Water Reaction are considered in a first part and a new experimental bench, dedicated to this study, is described. Anhydrous alternative options based on Na/CO 2 interaction are also presented. Then, in a second part, a functional study conducted on the cleaning pit is proposed. Based on experimental feedback, some calculations are carried out to estimate the sodium inventory on the fuel elements, and physical methods like hot inert gas sweeping to reduce this inventory are also presented. Finally, the implementation of these innovative solutions in cleaning pits is studied in regard to the expected performances. (authors)

  20. Innovative technologies on fuel assemblies cleaning for sodium fast reactors: First considerations on cleaning process

    Energy Technology Data Exchange (ETDEWEB)

    Simon, N.; Lorcet, H.; Beauchamp, F.; Guigues, E. [CEA, DEN, DTN Cadarache, F-13108 Saint-Paul-lez-Durance (France); Lovera, P.; Fleche, J. L. [CEA, DEN, DPC Saclay, F-91191 Gif-sur-Yvette (France); Lacroix, M. [CEA, DEN, DTN Cadarache, F-13108 Saint-Paul-lez-Durance (France); Carra, O. [AREVA / NP, 10 Rue Juliette Recamier, 69003 Lyon (France); Dechelette, F. [CEA, DEN, DTN Cadarache, F-13108 Saint-Paul-lez-Durance (France); Prele, G. [EDF/SEPTEN, 12-14 avenue Dutrievoz, 69628 Villeurbane Cedex (France); Rodriguez, G. [CEA, DEN, DTN Cadarache, F-13108 Saint-Paul-lez-Durance (France)

    2012-07-01

    Within the framework of Sodium Fast Reactor development, innovative fuel assembly cleaning operations are investigated to meet the GEN IV goals of safety and of process development. One of the challenges is to mitigate the Sodium Water Reaction currently used in these processes. The potential applications of aqueous solutions of mineral salts (including the possibility of using redox chemical reactions) to mitigate the Sodium Water Reaction are considered in a first part and a new experimental bench, dedicated to this study, is described. Anhydrous alternative options based on Na/CO{sub 2} interaction are also presented. Then, in a second part, a functional study conducted on the cleaning pit is proposed. Based on experimental feedback, some calculations are carried out to estimate the sodium inventory on the fuel elements, and physical methods like hot inert gas sweeping to reduce this inventory are also presented. Finally, the implementation of these innovative solutions in cleaning pits is studied in regard to the expected performances. (authors)

  1. Final status report in preparation for the chemical cleaning of Dresden-1, DNS-D1-034

    International Nuclear Information System (INIS)

    1981-09-01

    This report discusses the status of all of the activities conducted in preparation for the chemical cleaning of the Dresden-1 Nuclear Power Plant of Commonwealth Edison of Illinois. The metallurgical testing of a solvent and its ability to remove radioactivity are reviewed. Included are all engineering details relating to the modifications to the primary system to be able to perform the chemical cleaning and to rinse the cleaning solvent out of the equipment. A facility to store and process spent cleaning solutions is described in detail. Construction activities and preoperational activities are recounted. Licensing activities, quality assurance, safety, and radiation protection are discussed. The report includes recommendations for future actions for restarting the project when approval is received. All of the efforts discussed in this Final Status Report led to the conclusion that the chemical cleaning, as planned, was feasible. All of the necessary modifications and new equipment are in place and are operational

  2. Power generation from chemically cleaned coals: do environmental benefits of firing cleaner coal outweigh environmental burden of cleaning?

    DEFF Research Database (Denmark)

    Ryberg, Morten W.; Owsianiak, Mikolaj; Laurent, Alexis

    2015-01-01

    Power generation from high-ash coals is a niche technology for power generation, but coal cleaning is deemed necessary to avoid problems associated with low combustion efficiencies and to minimize environmental burdens associated with emissions of pollutants originating from ash. Here, chemical...... beneficiation of coals using acid and alkali–acid leaching procedures is evaluated as a potential coal cleaning technology employing life cycle assessment (LCA). Taking into account the environmental benefits from firing cleaner coal in pulverized coal power plants and the environmental burden of the cleaning...... itself, it is demonstrated that for a wide range of cleaning procedures and types of coal, chemical cleaning generally performs worse than combustion of the raw coals and physical cleaning using dense medium separation. These findings apply for many relevant impact categories, including climate change...

  3. Effectuality of Cleaning Workers' Training and Cleaning Enterprises' Chemical Health Hazard Risk Profiling

    Directory of Open Access Journals (Sweden)

    Abdulqadir M. Suleiman

    2015-12-01

    Conclusion: Training of cleaning workers lacks the prerequisite for suitability and effectiveness to counter risks of chemical health hazards. There is dereliction of duty by management in the sector resulting in a lack of competence among the cleaning workers. Instituting acceptable easily attainable safety competence level for cleaners will conduce to risk reduction, and enforcement of attainment of the competence level would be a positive step.

  4. Is dry cleaning all wet?

    International Nuclear Information System (INIS)

    Ryan, M.

    1993-01-01

    Chemical solvents from dry cleaning, particularly perchloroethylene (perc), have contributed to groundwater contamination, significant levels of air pollution in and around cleaners, and chemical accumulation in food. Questions are being raised about the process of cleaning clothes with chemical, and other less toxic cleaning methods are being explored. The EPA has focused attention on the 50 year old Friedburg method of cleaning, Ecoclean, which uses no dangerous chemicals and achieves comparable results. Unfortunately, the cleaning industry is resistant to change, so cutting back on amount of clothes that need dry cleaning and making sure labels aren't exaggerating when they say dry clean only, is frequently the only consumer option now

  5. ENHANCED CHEMICAL CLEANING: EFFECTIVENESS OF THE UV LAMP TO DECOMPOSE OXALATES

    Energy Technology Data Exchange (ETDEWEB)

    Ketusky, E.; Huff, T.; Sudduth, C.

    2010-01-19

    Enhanced Chemical Cleaning is a new process scheduled to begin cleaning Savannah River Site High Level Waste Tanks in 2012. It is an improvement over the current chemical cleaning method, in that it minimizes downstream impacts on the High Level Waste System. It is based on a state of the art scale removal process used on the secondary side of nuclear power plants, with modifications to accommodate the unique constraints created by the tanks. Both Enhanced Chemical Cleaning and the scale removal process are founded on dissolving metal oxides/hydroxides using oxalic acid, with subsequent oxalate decomposition via hydroxylation using ozone or peroxide, and UV light as a catalyst. A divergence Enhanced Chemical Cleaning has from nuclear power scale removal is the significantly increased solids concentration during oxalate decomposition. These solids can limit the ability of the UV light to create hydroxyl radicals, either by limiting the ability of the light to penetrate through the solution, or by increasing the fouling rate on the UV light. Both will decrease the overall catalytic effectiveness, thereby decreasing the concentration of formed hydroxyl radicals. The hydroxyl radicals are the driving force behind the oxalate decomposition. To understand the impact of increased solids, testing was performed using a medium pressure UV light inside an ozone supplied Oxalate Decomposition Reactor. Using a dissolved metal sludge simulant with an initial oxalate concentration greater than 12,000 ppm, and an initial pH of about 2.0, the spent acid solution was recirculated through the reactor, while the UV light was allowed to foul. For the first few hours, the oxalate decomposition rate was about 1,300 ppm/hour. After about 3 hours, enough time for the UV lamp to foul, the oxalate decomposition rate decreased to about 500 ppm/hour. The decomposition rate then remained roughly constant for the next 16 hours. Overall, testing showed that the oxalate destruction rate decreased

  6. Chemical cleaning of AGR boilers

    International Nuclear Information System (INIS)

    Moore, S.V.; Moore, W.; Rantell, A.

    1978-01-01

    AGR boilers are likely to require post service chemical cleaning to remove accumulated oxides at intervals of 15 - 35 kh. The need to clean will be based on an assessment of such factors as the development of flow imbalances through parallel tubes induced by the formation of rough oxide surfaces, an increasing risk of localised corrosion as the growth of porous oxides proceeds and the risk of tube blockage caused by the exfoliation of steam-grown oxides. The study has shown what heterogeneous multilayer oxides possessing a range of physical and chemical properties form on the alloy steels. They include porous and compact magnetites, chromium spinels and sesquioxide. Ammoniated citric acid has been shown to remove deposited and water-grown magnetites from the carbon and alloy steels but will not necessarily remove the substituted spinels grown on the alloy steels or the potentially spalling steam-grown magnetite on the A1SI 316 superheater. Citric acid supplemented with the reducing agent glyoxal completely removes all oxides from the boiler except the protective inner spinel formed on the 316. Removal of the spinels and compact magnetites occurs more by undercutting and physical detachment than by the dissolution. (author)

  7. Alternatives to Organic Solvents in Industrial Cleaning Processes

    DEFF Research Database (Denmark)

    Jacobsen, Thomas

    1998-01-01

    To control chemical hazards in work places, substitution of harmful substances with less harmful or non-toxic products is now a method used in many countries and in many companies. It has previously been demonstrated that it is desirable and possible to use non-volatile, low-toxic vegetable...... cleaning agents in offset printing companies instead of volatile, toxic organic solvents. The present study is based on a project with the aim of defining other industrial processes, where organic solvents used for cleaning or degreasing can be replaced by non-volatile, low-toxic products, which are based...... on esters from fatty acids of vegetable origin (vegetable esters - VE).The study indicates that industrial cleaning/degreasing with organic solvents may be substituted with VEs on metal surfaces and on some coated surfaces, in manufacture of paints and inks, use of paints, use of inks (printing), metal...

  8. ANALYSIS ON TECHNOLOGICAL PROCESSES CLEANING OIL PIPELINES

    Directory of Open Access Journals (Sweden)

    Mariana PǍTRAŞCU

    2015-05-01

    Full Text Available In this paper the researches are presented concerning the technological processes of oil pipelines.We know several technologies and materials used for cleaning the sludge deposits, iron and manganese oxides, dross, stone, etc.de on the inner walls of drinking water pipes or industries.For the oil industry, methods of removal of waste materials and waste pipes and liquid and gas transport networks are operations known long, tedious and expensive. The main methods and associated problems can be summarized as follows: 1 Blowing with compressed air.2 manual or mechanical brushing, sanding with water or dry.3 Wash with water jet of high pressure, solvent or chemical solution to remove the stone and hard deposits.4 The combined methods of cleaning machines that use water jets, cutters, chains, rotary heads cutters, etc.

  9. Chemical Agents: Personal Cleaning and Disposal of Contaminated Clothing

    Science.gov (United States)

    ... What CDC is Doing Blog: Public Health Matters Chemical Agents: Facts About Personal Cleaning and Disposal of ... on Facebook Tweet Share Compartir Some kinds of chemical accidents or attacks may cause you to come ...

  10. Chemical cleaning of nuclear (PWR) steam generators

    International Nuclear Information System (INIS)

    Welty, C.S. Jr.; Mundis, J.A.

    1982-01-01

    This paper reports on a significant research program sponsored by a group of utilities (the Steam Generator Owners Group), which was undertaken to develop a process to chemically remove corrosion product deposits from the secondary side of pressurized water reactor (PWR) power plant steam generators. Results of this work have defined a process (solvent system and application methods) that is capable of removing sludge and tube-to-tube support plate crevice corrosion products generated during operation with all-volatile treatment (AVT) water chemistry. Considers a plant-specific test program that includes all materials in the steam generator to be cleaned and accounts for the physical locations (proximity and contact) of those materials. Points out that prior to applying the process in an operational unit, the utility, with the participation of the NSSR vendor, must define allowable total corrosion to the materials of construction of the unit

  11. NICE3 SO3 Cleaning Process in Semiconductor Manufacturing

    International Nuclear Information System (INIS)

    Blazek, Steve

    1999-01-01

    This fact sheet explains how Anon, Inc., has developed a novel method of removing photoresist--a light-sensitive material used to produce semiconductor wafers for computers--from the computer manufacturing process at reduced cost and greater efficiency. The new technology is technically superior to existing semiconductor cleaning methods and results in reduced use of hazardous chemicals

  12. Combustion behaviour of ultra clean coal obtained by chemical demineralisation

    Energy Technology Data Exchange (ETDEWEB)

    F. Rubiera; A. Arenillas; B. Arias; J.J. Pis; I. Suarez-Ruiz; K.M. Steel; J.W. Patrick [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

    2003-10-01

    The increasing environmental concern caused by the use of fossil fuels and the concomitant need for improved combustion efficiency is leading to the development of new coal cleaning and utilisation processes. However, the benefits achieved by the removal of most mineral matter from coal either by physical or chemical methods can be annulled if poor coal combustibility characteristics are attained. In this work a high volatile bituminous coal with 6% ash content was subjected to chemical demineralisation via hydrofluoric and nitric acid leaching, the ash content of the clean coal was reduced to 0.3%. The original and treated coals were devolatilised in a drop tube furnace and the structure and morphology of the resultant chars was analysed by optical and scanning electron microscopies. The reactivity characteristics of the chars were studied by isothermal combustion tests in air at different temperatures in a thermogravimetric system. Comparison of the combustion behaviour and pollutant emissions of both coals was conducted in a drop tube furnace operating at 1000{sup o}C. The results of this work indicate that the char obtained from the chemically treated coal presents very different structure, morphology and reactivity behaviour than the char from the original coal. The changes induced by the chemical treatment increased the combustion efficiency determined in the drop tube furnace, in fact higher burnout levels were obtained for the demineralised coal.

  13. Challenges with modifications of the McClean Lake mill to process midwest ore

    International Nuclear Information System (INIS)

    Nguyen, T.T.; Backham, L.

    2010-01-01

    Midwest is a unique uranium deposit with exceptionally high arsenic content. The ore body is located 17 km west of the McClean Lake operation. The McClean Lake mill will be modified to process Midwest ore and handle solid wastes from the Midwest water treatment plant. This paper describes the modifications required of the McClean Lake mill, process challenges associated with treatment of the arsenic, and the possibility of recovering nickel and cobalt as a by-product. It also reviews the complexity in the design of the Midwest water treatment facility which incorporates reverse osmosis technology with conventional physical-chemical water treatment. (author)

  14. Dry Phosphorus silicate glass etching and surface conditioning and cleaning for multi-crystalline silicon solar cell processing

    International Nuclear Information System (INIS)

    Kagilik, Ahmed S.

    2014-01-01

    As an alternative to the wet chemical etching method, dry chemical etching processes for Phosphorus silicate glass [PSG} layer removal using Trifluormethane/Sulfur Hexafluoride (CHF 3 / SF 6 ) gas mixture in commercial silicon-nitride plasma enhanced chemical vapour deposition (SiN-PECVD) system is applied. The dependence of the solar cell performance on the etching temperature is investigated and optimized. It is found that the SiN-PECVD system temperature variation has a significant impact on the whole solar cell characteristics. A dry plasma cleaning treatment of the Si wafer surface after the PSG removal step is also investigated and developed. The cleaning step is used to remove the polymer film which is formed during the PSG etching using both oxygen and hydrogen gases. By applying an additional cleaning step, the polymer film deposited on the silicon wafer surface after PSG etching is eliminated. The effect of different plasma cleaning conditions on solar cell performance is investigated. After optimization of the plasma operating conditions, the performance of the solar cell is improved and the overall gain in efficiency of 0.6% absolute is yielded compared to a cell without any further cleaning step. On the other hand, the best solar cell characteristics can reach values close to that achieved by the conventional wet chemical etching processes demonstrating the effectiveness of the additional O 2 /H 2 post cleaning treatment.(author)

  15. CHEMICAL CLEANING OF NANOFILTRATION MEMBRANES FOULED BY ORGANIC MATTERS

    Directory of Open Access Journals (Sweden)

    CHARLENE C. H. KOO

    2016-07-01

    Full Text Available Membrane fouling is a term to describe non-integral substance on membrane surface which results in rapid decline of permeation flux and deteriorate the performance of membrane. Chemical cleaning agents especially like alkaline cleaners are most widely employed to restore the membrane performance. This research mainly investigated the potential use of sodium hydroxide (NaOH and sodium hypochlorite (NaOCl as the chemical cleaning agents to restore the permeate flux of organically fouled nanofiltration (NF membranes under varying applied pressure and flow condition. The performances of the cleaning protocols were quantified using flux recovery and resistance removal. The results demonstrated that NaOCl is more effective than NaOH. This observation is also in line with FTIR analysis in which the transmittance intensity showed by FTIR spectra of NaOCl is higher than that of NaOH. The results also reported that higher flux recovery and resistance removal were achieved when the fouled NF membranes were cleaned with higher concentration of chemical agents and applied pressure. However, the improvements of flux recovery and resistance removal by increasing the applied pressure were found insignificant at higher applied pressure range (16 to 18 bar than the lower applied pressure range (i.e. 12 to 14 bar. This research plays an important role by identifying the key parameters that could restore the flux of organically fouled NF membranes significantly.

  16. Chemical cleaning's role in tube failure prevention and correction

    International Nuclear Information System (INIS)

    Shields, K.J.; Dooley, R.B.

    2002-01-01

    Properly applied, chemical cleaning is a valuable tool used to prevent tube failures involving overheating and corrosion due to waterside deposits. In many cases, however, cleaning becomes yet an additional cost associated with correction of tube failure incidents. Discussion is focused on approaches taken to appraise tube waterside cleanliness and determine the need to clean, as typically practiced in conventional fossil plants. Also presented is an assessment of the suitability and limitations of these approaches to plants with heat recovery steam generator (HRSG) units. (orig.)

  17. Risk in cleaning: chemical and physical exposure.

    Science.gov (United States)

    Wolkoff, P; Schneider, T; Kildesø, J; Degerth, R; Jaroszewski, M; Schunk, H

    1998-04-23

    Cleaning is a large enterprise involving a large fraction of the workforce worldwide. A broad spectrum of cleaning agents has been developed to facilitate dust and dirt removal, for disinfection and surface maintenance. The cleaning agents are used in large quantities throughout the world. Although a complex pattern of exposure to cleaning agents and resulting health problems, such as allergies and asthma, are reported among cleaners, only a few surveys of this type of product have been performed. This paper gives a broad introduction to cleaning agents and the impact of cleaning on cleaners, occupants of indoor environments, and the quality of cleaning. Cleaning agents are usually grouped into different product categories according to their technical functions and the purpose of their use (e.g. disinfectants and surface care products). The paper also indicates the adverse health and comfort effects associated with the use of these agents in connection with the cleaning process. The paper identifies disinfectants as the most hazardous group of cleaning agents. Cleaning agents contain evaporative and non-evaporative substances. The major toxicologically significant constituents of the former are volatile organic compounds (VOCs), defined as substances with boiling points in the range of 0 degree C to about 400 degrees C. Although laboratory emission testing has shown many VOCs with quite different time-concentration profiles, few field studies have been carried out measuring the exposure of cleaners. However, both field studies and emission testing indicate that the use of cleaning agents results in a temporal increase in the overall VOC level. This increase may occur during the cleaning process and thus it can enhance the probability of increased short-term exposure of the cleaners. However, the increased levels can also be present after the cleaning and result in an overall increased VOC level that can possibly affect the indoor air quality (IAQ) perceived by

  18. Alternative Chemical Cleaning Methods for High Level Waste Tanks: Simulant Studies

    Energy Technology Data Exchange (ETDEWEB)

    Rudisill, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); King, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hay, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jones, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-11-19

    Solubility testing with simulated High Level Waste tank heel solids has been conducted in order to evaluate two alternative chemical cleaning technologies for the dissolution of sludge residuals remaining in the tanks after the exhaustion of mechanical cleaning and sludge washing efforts. Tests were conducted with non-radioactive pure phase metal reagents, binary mixtures of reagents, and a Savannah River Site PUREX heel simulant to determine the effectiveness of an optimized, dilute oxalic/nitric acid cleaning reagent and pure, dilute nitric acid toward dissolving the bulk non-radioactive waste components. A focus of this testing was on minimization of oxalic acid additions during tank cleaning. For comparison purposes, separate samples were also contacted with pure, concentrated oxalic acid which is the current baseline chemical cleaning reagent. In a separate study, solubility tests were conducted with radioactive tank heel simulants using acidic and caustic permanganate-based methods focused on the “targeted” dissolution of actinide species known to be drivers for Savannah River Site tank closure Performance Assessments. Permanganate-based cleaning methods were evaluated prior to and after oxalic acid contact.

  19. Annual report, spring 2015. Alternative chemical cleaning methods for high level waste tanks-corrosion test results

    Energy Technology Data Exchange (ETDEWEB)

    Wyrwas, R. B. [Savannah River Site (SRS), Aiken, SC (United States)

    2015-07-06

    The testing presented in this report is in support of the investigation of the Alternative Chemical Cleaning program to aid in developing strategies and technologies to chemically clean radioactive High Level Waste tanks prior to tank closure. The data and conclusions presented here were the examination of the corrosion rates of A285 carbon steel and 304L stainless steel when interacted with the chemical cleaning solution composed of 0.18 M nitric acid and 0.5 wt. % oxalic acid. This solution has been proposed as a dissolution solution that would be used to remove the remaining hard heel portion of the sludge in the waste tanks. This solution was combined with the HM and PUREX simulated sludge with dilution ratios that represent the bulk oxalic cleaning process (20:1 ratio, acid solution to simulant) and the cumulative volume associated with multiple acid strikes (50:1 ratio). The testing was conducted over 28 days at 50°C and deployed two methods to invest the corrosion conditions; passive weight loss coupon and an active electrochemical probe were used to collect data on the corrosion rate and material performance. In addition to investigating the chemical cleaning solutions, electrochemical corrosion testing was performed on acidic and basic solutions containing sodium permanganate at room temperature to explore the corrosion impacts if these solutions were to be implemented to retrieve remaining actinides that are currently in the sludge of the tank.

  20. Alternative Enhanced Chemical Cleaning Basic Studies Results FY09

    Energy Technology Data Exchange (ETDEWEB)

    Hay, M.; King, W.

    2010-05-05

    Due to the need to close waste storage tanks, chemical cleaning methods are needed for the effective removal of the heels. Oxalic acid is the preferred cleaning reagent for sludge heel dissolution, particularly for iron-based sludge, due to the strong complexing strength of the oxalate. However, the large quantity of oxalate added to the tank farm from oxalic acid based chemical cleaning has significant downstream impacts. Optimization of the oxalic acid cleaning process can potentially reduce the downstream impacts from chemical cleaning. To optimize oxalic acid usage, a detailed understanding of the chemistry of oxalic acid based sludge dissolution is required. Additionally, other acid systems may be required for specific waste components with low solubility in oxalic acid and as a means to reduce oxalic acid usage in general. Solubility tests were conducted using non-radioactive, pure metal phases known to be the primary phases present in High Level Waste sludge. The metal phases studied included the aluminum phases gibbsite and boehmite and the iron phases magnetite and hematite. Hematite and boehmite are expected to be the most difficult iron and aluminum phases to dissolve. These mineral phases have been identified in both SRS and Hanford High Level Waste sludge. Acids evaluated for dissolution included oxalic, nitric, and sulfuric acids. The results of the solubility tests indicate that oxalic and sulfuric acids are more effective for the dissolution of the primary sludge phases. For boehmite, elevated temperature will be required to promote effective phase dissolution in the acids studied. Literature reviews, thermodynamic modeling, and experimental results have all confirmed that pH control using a supplemental proton source (additional acid) is critical for minimization of oxalic acid usage during the dissolution of hematite. These results emphasize the importance of pH control in optimizing hematite dissolution in oxalic acid and may explain the somewhat

  1. Alternative Enhanced Chemical Cleaning Basic Studies Results FY09

    International Nuclear Information System (INIS)

    Hay, M.; King, W.

    2010-01-01

    Due to the need to close waste storage tanks, chemical cleaning methods are needed for the effective removal of the heels. Oxalic acid is the preferred cleaning reagent for sludge heel dissolution, particularly for iron-based sludge, due to the strong complexing strength of the oxalate. However, the large quantity of oxalate added to the tank farm from oxalic acid based chemical cleaning has significant downstream impacts. Optimization of the oxalic acid cleaning process can potentially reduce the downstream impacts from chemical cleaning. To optimize oxalic acid usage, a detailed understanding of the chemistry of oxalic acid based sludge dissolution is required. Additionally, other acid systems may be required for specific waste components with low solubility in oxalic acid and as a means to reduce oxalic acid usage in general. Solubility tests were conducted using non-radioactive, pure metal phases known to be the primary phases present in High Level Waste sludge. The metal phases studied included the aluminum phases gibbsite and boehmite and the iron phases magnetite and hematite. Hematite and boehmite are expected to be the most difficult iron and aluminum phases to dissolve. These mineral phases have been identified in both SRS and Hanford High Level Waste sludge. Acids evaluated for dissolution included oxalic, nitric, and sulfuric acids. The results of the solubility tests indicate that oxalic and sulfuric acids are more effective for the dissolution of the primary sludge phases. For boehmite, elevated temperature will be required to promote effective phase dissolution in the acids studied. Literature reviews, thermodynamic modeling, and experimental results have all confirmed that pH control using a supplemental proton source (additional acid) is critical for minimization of oxalic acid usage during the dissolution of hematite. These results emphasize the importance of pH control in optimizing hematite dissolution in oxalic acid and may explain the somewhat

  2. DEVELOPMENT OF AN INSOLUBLE SALT SIMULANT TO SUPPORT ENHANCED CHEMICAL CLEANING TESTS

    International Nuclear Information System (INIS)

    Eibling, R

    2008-01-01

    The closure process for high level waste tanks at the Savannah River Site will require dissolution of the crystallized salts that are currently stored in many of the tanks. The insoluble residue from salt dissolution is planned to be removed by an Enhanced Chemical Cleaning (ECC) process. Development of a chemical cleaning process requires an insoluble salt simulant to support evaluation tests of different cleaning methods. The Process Science and Engineering section of SRNL has been asked to develop an insoluble salt simulant for use in testing potential ECC processes (HLE-TTR-2007-017). An insoluble salt simulant has been developed based upon the residues from salt dissolution of saltcake core samples from Tank 28F. The simulant was developed for use in testing SRS waste tank chemical cleaning methods. Based on the results of the simulant development process, the following observations were developed: (1) A composition based on the presence of 10.35 grams oxalate and 4.68 grams carbonate per 100 grams solids produces a sufficiently insoluble solids simulant. (2) Aluminum observed in the solids remaining from actual waste salt dissolution tests is probably precipitated from sodium aluminate due to the low hydroxide content of the saltcake. (3) In-situ generation of aluminum hydroxide (by use of aluminate as the Al source) appears to trap additional salts in the simulant in a manner similar to that expected for actual waste samples. (4) Alternative compositions are possible with higher oxalate levels and lower carbonate levels. (5) The maximum oxalate level is limited by the required Na content of the insoluble solids. (6) Periodic mixing may help to limit crystal growth in this type of salt simulant. (7) Long term storage of an insoluble salt simulant is likely to produce a material that can not be easily removed from the storage container. Production of a relatively fresh simulant is best if pumping the simulant is necessary for testing purposes. The insoluble

  3. Mathematical modelling of flux recovery during chemical cleaning of tubular membrane fouled with whey proteins

    Directory of Open Access Journals (Sweden)

    Marković Jelena Đ.

    2009-01-01

    Full Text Available Membrane process efficiency in the dairy industry is impaired by the formation of deposits during filtration processes. This work describes cleaning procedures for ceramic tubular membrane (50 nm fouled with whey proteins. Also, mathematical modelling was performed to obtain models which allow deeper insight into the mechanisms involved during cleaning procedures. The caustic solutions (0.2%w/w, 0.4%w/w and 1.0%w/w NaOH and the mixture of two commercial detergents (0.8%w/w P3-ultrasil 69+0.5% w/w P3-ultrasil 67 and 1.2% P3-ultrasil 69+0.75 P3-ultrasil 67 were used as chemical cleaning agents. The results showed that the best flux recovery was achieved with 0.4%w/w NaOH solution. After analyzing the experimental data, five parameter and six parameter kinetic models were suggested for alkali and detergent cleaning, respectively. The changes of total and specific resistances, as well as the change of the effective pore diameter and deposit thickness during cleaning are estimated by applying these models.

  4. Cleaning of spent solvent and method of processing cleaning liquid waste

    International Nuclear Information System (INIS)

    Ozawa, Masaki; Kawada, Tomio; Tamura, Nobuhiko.

    1993-01-01

    Spent solvents discharged from a solvent extracting step mainly comprise n-dodecane and TBP and contain nuclear fission products and solvent degradation products. The spent solvents are cleaned by using a sodium chloride free detergent comprising hydrazine oxalate and hydrazine carbonate in a solvent cleaning device. Nitric acid is added to the cleaning liquid wastes containing spent detergents extracted from the solvent cleaning device, to control an acid concentration. The detergent liquid wastes of controlled acid concentration are sent to an electrolysis oxidation bath as electrolytes and electrochemically decomposed in carbonic acid gas, nitrogen gas and hydrogen gas. The decomposed gases are processed as off gases. The decomposed liquid wastes are processed as a waste nitric acid solution. This can provide more effective cleaning. In addition, the spent detergent can be easily decomposed in a room temperature region. Accordingly, the amount of wastes can be decreased. (I.N.)

  5. Fabrication of superhydrophilic or superhydrophobic self-cleaning metal surfaces using picosecond laser pulses and chemical fluorination

    Science.gov (United States)

    Zheng, Buxiang; Jiang, Gedong; Wang, Wenjun; Mei, Xuesong

    2016-05-01

    Bioinspired superhydrophilic/phobic self-cleaning surfaces have recently drawn a lot of interest in both fundamental and applied research. A hybrid method to produce the self-cleaning property of micro/nanostructured surface using ultra-fast laser pulses followed by chemical fluorination is proposed. The typical micro/nanocomposite structures that form from microporous arrays and microgroove groups have been processed by picosecond laser on titanium alloy surface. The surface hydrophilic/phobic and self-cleaning properties of micro/nanostructures before and after fluorination with fluoroalkyl-silane were investigated using surface contact angle measurements. The results indicate that surface properties change from hydrophilic to hydrophobic after fluorination, and the micro/nanostructured surface with increased roughness contributes to the improvement of surface hydrophobicity. The micro/nanomodification can make the original hydrophilic titanium alloy surface more hydrophilic or superhydrophilic. It also can make an originally hydrophobic fluorinated titanium alloy surface more hydrophobic or superhydrophobic. The produced micro/nanostructured titanium alloy surfaces show excellent self-cleaning properties regardless of the fluorination treatment, although the fluorinated surfaces have slightly better self-cleaning properties. It is found that surface treatment using ultra-fast laser pulses and subsequent chemical fluorination is an effective way to manipulate surface wettability and obtain self-cleaning properties.

  6. Weld region corrosion during chemical cleaning of PWR [pressurized-water reactor] steam generators: Volume 2, Tests and analyses: Final report

    International Nuclear Information System (INIS)

    Barna, J.L.; Bozeka, S.A.; Jevec, J.M.

    1987-07-01

    The potential for preferential corrosion of steam generator weld regions during chemical cleaning using the generic SGOG solvents was investigated. The investigations included development and use of a corrosion assessment test facility which measured corrosion currents in a realistic model of the steam generator geometry in the vicinity of a specific weld during a simulated chemical dissolution of sludge consisting of essentially pure magnetite. A corrosion monitoring technique was developed and qualified. In this technique free corrosion rates measured by linear polarization techniques are added to corrosion rates calculated from galvanic current measured using a zero resistance ammeter to give an estimate of total corrosion rate for a galvanically corroding material. An analytic modeling technique was developed and proved useful in determining the size requirements for the weld region mockup used in the corrosion assessment test facility. The technique predicted galvanic corrosion rates consistent with that observed in a corrosion assessement test when polarization data used as model input were obtained on-line during the test. The test results obtained during this investigation indicated that chemical cleaning using the SGOG magnetite dissolution solvent can be performed with a small amount of corrosion of secondary side internals and pressure boundary welds. The maximum weld region corrosion measured during a typical chemical cleaning cycle to remove essentially pure magnetite sludge was about 8 mils. However, additional site specific weld region corrosion assessment testing and qualification will be required prior to chemical cleaning steam generators at a specific plant. Recommendations for site specific qualification of chemical cleaning processes and for use of process monitors and on-line corrosion instrumentation are included in this report

  7. Cleaning Process Development for Metallic Additively Manufactured Parts

    Science.gov (United States)

    Tramel, Terri L.; Welker, Roger; Lowery, Niki; Mitchell, Mark

    2014-01-01

    Additive Manufacturing of metallic components for aerospace applications offers many advantages over traditional manufacturing techniques. As a new technology, many aspects of its widespread utilization remain open to investigation. Among these are the cleaning processes that can be used for post finishing of parts and measurements to verify effectiveness of the cleaning processes. Many cleaning and drying processes and measurement methods that have been used for parts manufactured using conventional techniques are candidates that may be considered for cleaning and verification of additively manufactured parts. Among these are vapor degreasing, ultrasonic immersion and spray cleaning, followed by hot air drying, vacuum baking and solvent displacement drying. Differences in porosity, density, and surface finish of additively manufactured versus conventionally manufactured parts may introduce new considerations in the selection of cleaning and drying processes or the method used to verify their effectiveness. This presentation will review the relative strengths and weaknesses of different candidate cleaning and drying processes as they may apply to additively manufactured metal parts for aerospace applications. An ultrasonic cleaning technique for exploring the cleanability of parts will be presented along with an example using additively manufactured Inconel 718 test specimens to illustrate its use. The data analysis shows that this ultrasonic cleaning approach results in a well-behaved ultrasonic cleaning/extraction behavior. That is, it does not show signs of accelerated cavitation erosion of the base material, which was later confirmed by neutron imaging. In addition, the analysis indicated that complete cleaning would be achieved by ultrasonic immersion cleaning at approximately 5 minutes, which was verified by subsequent cleaning of additional parts.

  8. Study of chemical cleaning technique for removing sludge in secondary side of PWR SG

    International Nuclear Information System (INIS)

    Zhang Mengqin; Zhang Shufeng; Pan Qingchun; Yu Jinghua; Hou Shufeng

    1993-12-01

    The effect of components, concentration, pH, temperature, cleaning time and flowrate of chemical cleaning solvent made from EDTA mainly on Fe 3 O 4 solubility and corrosion rate of A3 carbon steel, S271 low alloy steel and 800 alloy are introduced. A small chemical cleaning test loop (30L) was built to study the cleaning technique. The effect of residue of chemical cleaning solvent on anti-corrosion performance of materials has been studied under the simulation condition of PWR (pressure water reactor) SG (steam generator) secondary side. The results show that the chemical solvent (pH = 7, 10% EDTA, 1% assistance solvent and 0.25% inhibitor A) can dissolve Fe 3 O 4 18 ∼23 g/L under the conditions of 93 +- 5 degree C, 8 hours and 112 r/min (1.8 ∼ 2.0 t/h). The corrosion rate of material is low. When the residue of EDTA is less than 0.01% there is no impact on the anti-corrosion performance of materials in PWR SG secondary side at normal operation condition (260 +- 5 degree C)

  9. Method of cleaning oil slicks and chemical spills

    International Nuclear Information System (INIS)

    Billings, L.

    1992-01-01

    This patent describes a method of cleaning a floating chemical spill on a body of water. It comprises: providing a quantity of popular bark-based pelleted or granular product, flotation means and a flexible net having openings generally smaller than the smallest whole pellet dimension of the pelleted product, spreading the net over a chemical spill on the body of water, connecting the floatation means to the net thereby supporting the net adjacent the surface of the body of water, placing the poplar bark-based product on the net, absorbing the floating chemical spill into the product, and removing the chemical soaked product from the body of water

  10. Preventive acid chemical cleaning operation (PACCO) on steam generator in French nuclear power plants

    International Nuclear Information System (INIS)

    Traino, Jules; Ruiz Martinez, Jose Thomas; Rottner, Bernard; Vedova, Eric

    2014-01-01

    Steam Generators (SG) usually present important deposit loading and Tube Support Blockage, resulting from Secondary Side corrosion products. These phenomena modify SG behavior which can lead to safety, heat exchange performance and lifetime problems. In this context, a Chemical Cleaning Process (PACCO) was designed to solve the issue. After almost two years of intensive lab tests, pilot simulation and mock-ups, the chemical process was finally qualified by EDF. The aim of the work was firstly the development in laboratory of a chemical process that could eliminate partially the deposit loading, respecting the integrity of materials and gas emission limits. Secondly, the objective was the design and the implementation of the process on-site. The process has been applied successfully in 3 SG in Dampierre nuclear power plant in France on July 2013. The main results were: - Corrosion < 100 μm. - 40% of the initial deposit loading, removed by SG. (authors)

  11. Tube micro-fouling, boiling and steam pressure after chemical cleaning

    International Nuclear Information System (INIS)

    Hu, M.H.

    1998-01-01

    This paper presents steam pressure trends after chemical cleaning of steam generator tubes at four plants. The paper also presents tube fouling factor that serves as an objective parameter to assess tubing boiling conditions for understanding the steam pressure trend. Available water chemistry data helps substantiate the concept of tube micro-fouling, its effect on tubing boiling, and its impact on steam pressure. All four plants experienced a first mode of decreasing steam pressure in the post-cleaning operation. After 3 to 4 months of operation, the decreasing trend stopped for three plants and then restored to a pre-cleaning value or better. The fourth plant is soil in decreasing trend after 12 months of operation. Dissolved chemicals, such as silica, titanium can precipitate on tube surface. The precipitate micro-fouling can deactivate or eliminate boiling nucleation sites. Therefore, the first phase of the post-cleaning operation suffered a decrease in steam pressure or an increase in fouling factor. It appears that micro fouling by magnetite deposit can activate or create more bubble nucleation sites. Therefore, the magnetite deposit micro-fouling results in a decrease in fouling factor, and a recovery in steam pressure. Fully understanding the boiling characteristics of the tubing at brand new, fouled and cleaned conditions requires further study of tubing surface conditions. Such study should include boiling heat transfer tests and scanning electronic microscope examination. (author)

  12. Tests of an environmental and personnel safe cleaning process for BNL accelerator and storage ring components

    International Nuclear Information System (INIS)

    Foerster, C.L.; Lanni, C.; Lee, R.; Mitchell, G.; Quade, W.

    1996-10-01

    A large measure of the successful operation of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) for over a decade can be attributed to the cleaning of its UHV components during and after construction. A new UHV cleaning process, which had to be environmentally and personnel safe, was needed to replace the harsh, unfriendly process which was still in use. Dow Advanced Cleaning Systems was contracted to develop a replacement process without the use of harsh chemicals and which must clean vacuum surfaces as well as the existing process. Acceptance of the replacement process was primarily based on Photon Stimulated Desorption (PSD) measurements of beam tube samples run on NSLS beam line U10B. One meter long beam tube samples were fabricated from aluminum, 304 stainless steel and oxygen free copper. Initially, coupon samples were cleaned and passed preliminary testing for the proposed process. Next, beam tube samples of each material were cleaned, and the PSD measured on beam line U10B using white light with a critical energy of 487 ev. Prior to cleaning, the samples were contaminated with a mixture of cutting oils, lubricants, vacuum oils and vacuum grease. The contaminated samples were then baked. Samples of each material were also cleaned with the existing process after the same preparation. Beam tube samples were exposed to between 10 22 and 10 23 photons per meter for a PSD measurement. Desorption yields for H 2 , CO, CO 2 , CH 4 and H 2 O are reported for both the existing cleaning and for the replacement cleaning process. Preliminary data, residual gas scans, and PSD results are given and discussed. The new process is also compared with new cleaning methods developed in other laboratories

  13. In-Situ Ion Source Cleaning: Review of Chemical Mechanisms and Evaluation Data at Production Fabs

    International Nuclear Information System (INIS)

    Kaim, R.; Bishop, S.; Byl, O.; Eldridge, D.; Marganski, P.; Mayer, J.; Sweeney, J.; Yedave, S.; Fuchs, D.; Spreitzer, S.; Vogel, J.; Dunn, J.; Lundquist, P.; Rolland, J.; Romig, T.; Newman, D.; Mitchell, M.; Ditzler, K.

    2008-01-01

    Since the concept of chemical in-situ ion implanter cleaning was introduced at IIT2006 [1], evaluations of the XeF 2 cleaning technology have taken place or are ongoing at more than 40 production fabs worldwide. Testing has been focused on assessing effects of cleaning in the source arc chamber and extraction regions. In this paper we describe use of the cleaning technology in a production environment and summarize evaluation data showing advantages of the technology for improving ion source life, reducing glitching, improving beam auto-tuning and avoiding species cross-contamination. More details of the evaluations are given in several separate papers submitted to this Conference. We have supplemented the fab production data with laboratory experiments designed to investigate the reactivity of XeF 2 and fundamental aspects of the source deposition and cleaning processes. These experiments are summarized here, and more details can be found in separate papers submitted to this Conference

  14. PWR steam generator chemical cleaning. Phase I: Final report, Volume I

    International Nuclear Information System (INIS)

    1978-07-01

    Two chemical cleaning solvent systems and two application methods were developed to remove the sludge in nuclear steam generators and to remove the corrosion products in the annuli between the steam generator tubes and the support plates. Laboratory testing plus subsequent pilot testing has demonstrated that, in a reasonable length of time, both solvents are capable of dissolving significant amounts of sludge, and of dissolving tightly packed magnetite in tube/support plate crevices. Further, tests have demonstrated that surface losses of the materials of construction in steam generators can be controlled to acceptable limits for the duration of the required cleaning period. Areas requiring further study and test have been identified, and a preliminary procedure for chemical cleaning nuclear steam generators has been chosen subject to quantification based on additional tests prior to actual in-plant demonstration

  15. Disposal and handling of nuclear steam generator chemical cleaning wastes

    International Nuclear Information System (INIS)

    Larrick, A.P.; Schneidmiller, D.

    1978-01-01

    A large number of pressurized water nuclear reactor electrical generating plants have experienced a corrosion-related problem with their steam generators known as denting. Denting is a mechanical deformation of the steam generator tubes that occurs at the tube support plates. Corrosion of the tube support plates occurs within the annuli through which the tubes pass and the resulting corrosion oxides, which are larger in volume than the original metal, compress and deform the tubes. In some cases, the induced stresses have been severe enough to cause tube and/or support cracking. The problem was so severe at the Turkey Point and Surrey plants that the tubing is being replaced. For less severe cases, chemical cleaning of the oxides, and other materials which deposit in the annuli from the water, is being considered. A Department of Energy-sponsored program was conducted by Consolidated Edison Co. of New York which identified several suitable cleaning solvents and led to in-plant chemical cleaning pilot demonstrations in the Indian Point Unit 1 steam generators. Current programs to improve the technology are being conducted by the Electric Power Research Institute, and the three PWR NSSS vendors with the assistance of numerous consultants, vendors, and laboratories. These programs are expected to result in more effective, less corrosive solvents. However, after a chemical cleaning is conducted, a large problem still remains- that of disposing of the spent wastes. The paper summarizes some of the methods currently available for handling and disposal of the wastes

  16. Preliminary Results of Cleaning Process for Lubricant Contamination

    Science.gov (United States)

    Eisenmann, D.; Brasche, L.; Lopez, R.

    2006-03-01

    Fluorescent penetrant inspection (FPI) is widely used for aviation and other components for surface-breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. Prior to FPI, components are cleaned using a variety of cleaning methods which are selected based on the alloy and the soil types which must be removed. It is also important that the cleaning process not adversely affect the FPI process. There are a variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. To assess the effectiveness of typical cleaning processes on removal of these contaminants, a study was initiated at an airline overhaul facility. Initial results of the cleaning study for lubricant contamination in nickel, titanium and aluminum alloys will be presented.

  17. Preliminary Results of Cleaning Process for Lubricant Contamination

    International Nuclear Information System (INIS)

    Eisenmann, D.; Brasche, L.; Lopez, R.

    2006-01-01

    Fluorescent penetrant inspection (FPI) is widely used for aviation and other components for surface-breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. Prior to FPI, components are cleaned using a variety of cleaning methods which are selected based on the alloy and the soil types which must be removed. It is also important that the cleaning process not adversely affect the FPI process. There are a variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. To assess the effectiveness of typical cleaning processes on removal of these contaminants, a study was initiated at an airline overhaul facility. Initial results of the cleaning study for lubricant contamination in nickel, titanium and aluminum alloys will be presented

  18. Evaluation of EDTA based chemical formulations for the cleaning of monel-400 tubed steam generators

    International Nuclear Information System (INIS)

    Velmurugan, S.; Rufus, A.L.; Sathyaseelan, V.S.; Kumar, P.S.; Veena, S.N.; Srinivasan, M.P.; Narasimhan, S.V.

    1998-01-01

    The Steam Generator (SG) is an important component in any nuclear power plant which contributes significantly for the over all performance of the reactor. The failure of SG tubes occurs mainly by corrosion under accelerated conditions caused by fouling. There is continuous ingress of the corrosion products and ionic impurities from the condenser and feed train of the secondary heat transfer system. The corrosion products accumulate in the stagnant areas near the tube sheet, over the tube support plates and in the tube to tube support plate crevices. These accumulated deposits help to concentrate the aggressive impurities and induce a variety of corrosion processes affecting the structural materials and finally leading to failure of the SG tube. Scale forming impurities can deposit over the tube surfaces and result in reduction of heat transfer efficiency and over heating of the surfaces. Every effort is being made to control the transport of impurities to the steam generator. Increased blow down, installation of condensate polishers and use of all volatile amines have helped to reduce the corrosion product and ionic impurities input into the steam generators of PHWRs. Despite these efforts, failures of SG tubes in PHWRs have been reported. Hence, attempts are being made to develop chemical formulations to clean the deposits accumulated in the steam generators. The EPRI-SGOG chemical cleaning process has been tried with good success in steam generators of different designs including the steam generators of PHWRs. This paper discusses the work on the evaluation of EDTA based chemical cleaning formulations for monel-400 tubed steam generators of PHWRs. (author)

  19. Low-temperature wafer direct bonding of silicon and quartz glass by a two-step wet chemical surface cleaning

    Science.gov (United States)

    Wang, Chenxi; Xu, Jikai; Zeng, Xiaorun; Tian, Yanhong; Wang, Chunqing; Suga, Tadatomo

    2018-02-01

    We demonstrate a facile bonding process for combining silicon and quartz glass wafers by a two-step wet chemical surface cleaning. After a post-annealing at 200 °C, strong bonding interfaces with no defects or microcracks were obtained. On the basis of the detailed surface and bonding interface characterizations, the bonding mechanism was explored and discussed. The amino groups terminated on the cleaned surfaces might contribute to the bonding strength enhancement during the annealing. This cost-effective bonding process has great potentials for silicon- and glass-based heterogeneous integrations without requiring a vacuum system.

  20. Annual Report, Fall 2016: Alternative Chemical Cleaning of Radioactive High Level Waste Tanks - Corrosion Test Results

    International Nuclear Information System (INIS)

    Wyrwas, R. B.

    2016-01-01

    The testing presented in this report is in support of the investigation of the Alternative Chemical Cleaning program to aid in developing strategies and technologies to chemically clean radioactive High Level Waste tanks prior to tank closure. The data and conclusions presented here were the examination of the corrosion rates of A285 carbon steel and 304L stainless steel exposed to two proposed chemical cleaning solutions: acidic permanganate (0.18 M nitric acid and 0.05M sodium permanganate) and caustic permanganate. (10 M sodium hydroxide and 0.05M sodium permanganate). These solutions have been proposed as a chemical cleaning solution for the retrieval of actinides in the sludge in the waste tanks, and were tested with both HM and PUREX sludge simulants at a 20:1 ratio.

  1. Annual Report, Fall 2016: Alternative Chemical Cleaning of Radioactive High Level Waste Tanks - Corrosion Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Wyrwas, R. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-01

    The testing presented in this report is in support of the investigation of the Alternative Chemical Cleaning program to aid in developing strategies and technologies to chemically clean radioactive High Level Waste tanks prior to tank closure. The data and conclusions presented here were the examination of the corrosion rates of A285 carbon steel and 304L stainless steel exposed to two proposed chemical cleaning solutions: acidic permanganate (0.18 M nitric acid and 0.05M sodium permanganate) and caustic permanganate. (10 M sodium hydroxide and 0.05M sodium permanganate). These solutions have been proposed as a chemical cleaning solution for the retrieval of actinides in the sludge in the waste tanks, and were tested with both HM and PUREX sludge simulants at a 20:1 ratio.

  2. Tests of an environmental and personnel safe cleaning process for Brookhaven National Laboratory accelerator and storage ring components

    International Nuclear Information System (INIS)

    Foerster, C.L.; Lanni, C.; Lee, R.; Mitchell, G.; Quade, W.

    1997-01-01

    A large measure of the successful operation of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) for over a decade can be attributed to the cleaning of its ultrahigh vacuum (UHV) components during and after construction. A new UHV cleaning process, which has to be environmentally and personnel safe, is needed to replace the harsh, unfriendly process which is still in use. Dow Advanced Cleaning Systems was contracted to develop a replacement process without the use of harsh chemicals and which must clean vacuum surfaces as well as the existing process. Acceptance of the replacement process was primarily based on photon stimulated desorption (PSD) measurements of beam tube samples run on NSLS beam line U10B. One meter long beam tube samples were fabricated from aluminum, 304 stainless steel, and oxygen-free copper. Initially, coupon samples were cleaned and passed preliminary testing for the proposed process. Next, beam tube samples of each material were cleaned, and the PSD measured on beam line U10B using white light with a critical energy of 487 eV. Prior to cleaning, the samples were contaminated with a mixture of cutting oils, lubricants, vacuum oils, and vacuum grease. The contaminated samples were then baked. Samples of each material were also cleaned with the existing process after the same preparation. Beam tube samples were exposed to between 10 22 and 10 23 photons per meter for a PSD measurement. Desorption yields for H 2 , CO, CO 2 , CH 4 , and H 2 O are reported for both the existing cleaning and for the replacement cleaning process. Preliminary data, residual gas scans, and PSD results are given and discussed. The new process is also compared with new cleaning methods developed in other laboratories. After modification, the new UHV cleaning process was accepted by BNL

  3. EDF feedback on recent EPRI SGOG SG chemical cleanings applications for TSP blockage reduction and heat transfer recover

    International Nuclear Information System (INIS)

    Dijoux, M.; De Bouvier, O.; Mercier, S.; Pages, D.; Bretelle, J.-L.; Leclercq, P.; Mermillod, A.

    2010-01-01

    Between 2007 and 2008, six Steam Generators Chemical Cleanings (SGCC) with the inhibitor free high temperature process were applied on EDF PWR units. The main goal was to reduce the excessive Tube Support Plate blockages observed on several units of the EDF fleet and the consequences on wide range levels and the risk of tube cracks. The heat transfer recovery was the second objective. Despite the correct results obtained, the corrosion impact of the high temperature process on internal metallic surfaces, higher than expected, and the environmental issues led EDF to move to a new cleaning process. The low temperature process developed by EPRI SGOG and applied for many years was selected for the same purpose. Some qualification laboratory tests were performed by Dominion Engineering Inc (DEI) to demonstrate the innocuousness an the efficiency of the process to achieve these goals. The EPRI SGOG process was then applied seven times by Westinghouse on the EDF units Cruas 3, Cruas 2, Belleville 1, Cattenom 1, Cattenom 3, Chinon B3 and Cattenom 4 between 2008 and 2010. All these units operate from the initial start at low AVT pH 25 o C (9,2) in the secondary circuit. Due to copper presence in the deposits to remove, the cleaning sequence 'Copper - Iron - Copper steps' was performed each time. After a short description of the process, including the specific adaptation in France, lessons learned are reported in this paper in the following areas: process monitoring, corrosion, efficiency, liquid and gaseous wastes, chemical pollution during start-up. Based on the 3 first applications in 2008, some modifications of the process were implemented, particularly for the copper step. For the units cleaned, 1100 to 4500 kg of deposits per SG have been removed, including TS sludge lancing. The reduction of TSP blockages was satisfying. The effect on steam pressure improvement and the wide range level is then discussed. The paper concludes on EDF perspectives for soft

  4. Heat exchanger cleaning

    International Nuclear Information System (INIS)

    Gatewood, J.R.

    1980-01-01

    A survey covers the various types of heat-exchange equipment that is cleaned routinely in fossil-fired generating plants, the hydrocarbon-processing industry, pulp and paper mills, and other industries; the various types, sources, and adverse effects of deposits in heat-exchange equipment; some details of the actual procedures for high-pressure water jetting and chemical cleaning of some specific pieces of equipment, including nuclear steam generators. (DN)

  5. Effectiveness of aged graffiti cleaning on granite by chemical and mechanical procedures

    Science.gov (United States)

    Gomes, Vera; Dionísio, Amélia; Santiago Pozo-Antonio, José

    2017-04-01

    Granite is one of the most common building stones in the European Cultural Heritage mainly in Northwest Iberian Peninsula. Nowadays, graffiti when a result of an act of vandalism is one of the most important threat, involving a serious risk to heritage sustainability. The cleaning is expensive and in most of the cases, the complete removal is not achieved. Many cities worldwide spend huge amounts of money in cleaning campaigns and European Commission started to create urban environment policies to prevent and eliminate graffiti and also finance projects to develop new cleaning procedures and antigraffiti coatings1,2. However, in many cases graffiti is applied in monuments and façades without antigraffiti and in real practice, they are only cleaned after being long exposure to the atmosphere, reaction with the environment (rain and atmospheric pollutants) and also with the substrate, leading changes in their physical and chemical properties. However, no scientific studies focused on graffiti aging were found and also on the influence of the aging on the cleaning effectiveness, which is always evaluated with fresh graffiti. Therefore, the need to optimize the cleaning of aged graffiti is urgent. This paper aims to study the influence of the exposition of graffiti paintings to one of the most important urban contaminant SO2 on the cleaning effectiveness of graffiti on the valuable ornamental granite Rosa Porriño. Two different chemical products and two different mechanical procedures based on low pressure projection (wet and dry) were evaluated. Four different colour graffiti paintings (red, black, blue and silver) with different compositions were tested. The criteria for assessing the global cleaning effectiveness was considering the graffiti extraction and also the damage induced on the substrate through changes in the chromatic parameters, static contact angle and surface roughness of the stones, identification of deleterious products and modification of the

  6. PWR steam generator chemical cleaning. Phase II. Final report

    International Nuclear Information System (INIS)

    1980-01-01

    Two techniques believed capable of chemically dissolving the corrosion products in the annuli between tubes and support plates were developed in laboratory work in Phase I of this project and were pilot tested in Indian Point Unit No. 1 steam generators. In Phase II, one of the techniques was shown to be inadequate on an actual sample taken from an Indian Point Unit No. 2 steam generator. The other technique was modified slightly, and it was demonstrated that the tube/support plate annulus could be chemically cleaned effectively

  7. Materials and boiler rig testing to support chemical cleaning of once-through AGR boilers

    International Nuclear Information System (INIS)

    Tice, D.R.; Platts, N.; Raffel, A.S.; Rudge, A.

    2002-01-01

    An extensive programme of work has been carried out to evaluate two candidate inhibited cleaning solutions for possible implementation on plant, which would be the first chemical clean of an AGR boiler. The two candidate cleaning solutions considered were a Stannine-inhibited citric acid/formic acid mixture (GOM106) and inhibited hydrofluoric acid. Citric acid-based cleaning processes are widely used within the UK Power Industry. The GOM106 solution, comprising a mixture of 3% citric acid, 0.5% formic acid and 0.05% Stannine LTP inhibitor, buffered with ammonia to pH 3.5, was developed specifically for the AGR boilers during the 1970's. Although a considerable amount of materials testing work was carried out by British Energy's predecessor companies to produce a recommended cleaning procedure there were some remaining concerns with the use of GOM106, from these earlier studies, for example, an increased risk of pitting attack associated with the removal of thick 9Cr oxide deposits and a risk of unacceptable damage in critical locations such as the upper transition joints and other weld locations. Hence, additional testing was still required to validate the solution for use on plant. Inhibited hydrofluoric acid (HFA) was also evaluated as an alternative reagent to GOM106. HFA has been used extensively for cleaning mild and low'alloy steel boiler tubes in fossil-fired plant in the UK and elsewhere in Europe and is known to remove oxide quickly. Waste treatment is also easier than for the GOM106 process and some protection against damage to the boiler tube materials is provided by complexing of fluoride with ferric ion. Validation of the potential reagents and inhibitors was achieved by assessing the rate and effectiveness of oxide removal from specimens of helical boiler tubing and welds, together with establishing the extent of any metal loss or localised damage. The initial materials testing resulted in the inhibited ammoniated citric / formic acid reagent being

  8. Emerging forward osmosis (FO) technologies and challenges ahead for clean water and clean energy applications

    KAUST Repository

    Chung, Tai-Shung; Li, Xue; Ong, Rui Chin; Ge, Qingchun; Wang, Honglei; Han, Gang

    2012-01-01

    The purpose of this short review is to share our understanding and perspectives with the chemical, environmental, water and osmotic power communities on FO processes in order to conduct meaningful R & D and develop effective and sustainable FO technologies for clean water and clean energy. © 2012 Elsevier Ltd. All rights reserved.

  9. Emerging forward osmosis (FO) technologies and challenges ahead for clean water and clean energy applications

    KAUST Repository

    Chung, Tai-Shung

    2012-08-01

    The purpose of this short review is to share our understanding and perspectives with the chemical, environmental, water and osmotic power communities on FO processes in order to conduct meaningful R & D and develop effective and sustainable FO technologies for clean water and clean energy. © 2012 Elsevier Ltd. All rights reserved.

  10. Review of cleaning techniques and their effects on the chemical composition of foliar samples

    Energy Technology Data Exchange (ETDEWEB)

    Rossini Oliva, S.; Raitio, H.

    2003-07-01

    Chemical foliar analysis is a tool widely used to study tree nutrition and to monitor the impact and extent of air pollutants. This paper reviews a number of cleaning methods, and the effects of cleaning on foliar chemistry. Cleaning may include mechanical techniques such as the use of dry or moistened tissues, shaking, blowing, and brushing, or use various washing techniques with water or other solvents. Owing to the diversity of plant species, tissue differences, etc., there is no standard procedure for all kinds of samples. Analysis of uncleaned leaves is considered a good method for assessing the degree of air contamination because it provides an estimate of the element content of the deposits on leaf surfaces or when the analysis is aimed at the investigation of transfer of elements along the food chain. Sample cleaning is recommended in order (1) to investigate the transfer rate of chemical elements from soil to plants, (2) to qualify the washoff of dry deposition from foliage and (3) to separate superficially absorbed and biomass-incorporated elements. Since there is not a standard cleaning procedure for all kinds of samples and aims, it is advised to conduct a pilot study in order to be able to establish a cleaning procedure to provide reliable foliar data. (orig.)

  11. Development of the ultra-clean dry cleanup process for coal-based syngases: pilot-scale evaluation

    Energy Technology Data Exchange (ETDEWEB)

    R.B. Slimane; P.V. Bush; J.L. Aderhold, Jr.; B.G. Bryan; R.A. Newby; D. A. Horazak; S.C. Jain [Gas Technology Institute, Des Plaines, IL (United States)

    2005-07-01

    This paper reports on a recent successful pilot-scale evaluation of the Ultra-Clean Process performance at a 10-ton/day coal gasifier facility. In these tests, carbonaceous feedstocks were gasified, using GTI's fluidized bed U-GAS{reg_sign} gasification technology, to generate syngas. The raw syngas was then conditioned and fed to the UCP test section for deep cleaning to meet very stringent cleaning requirements for chemical feedstocks or liquid-fuel synthesis applications, or for fuel-cell power generation. Fine particle sorbents for sulfur, halide, and mercury removal were injected into the syngas upstream of two stages of particulate controlled devices, 'barrier filter-reactors', coupling efficient particle capture with an effective entrained and filter cake reaction environment for very effective multiple contaminant removal. The goal of the test program was to confirm sorbent selection, filter-reactor operating parameters and sorbent-to-contaminant ratios, which were previously determined in the laboratory to have potential to reduce contaminant concentrations to very low levels. The pilot-scale data developed are being used to update conceptual evaluations, which have shown the technical feasibility, cost effectiveness and commercial merit for the Ultra-Clean Process compared to conventional, Rectisol-based syngas cleaning. 10 refs., 5 figs.

  12. A Study on an Executive Technique and Activation of Clean Production in Chemical Industry

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Seong Yong; Lee, Hee Seok; Kim, Kang Seok [Korea Environment Institute, Seoul (Korea)

    2000-12-01

    Clean production does not only make the sustainable development possible through preventing the deterioration of the environmental pollution from the expansion of industrialization but also enhance the company's competitiveness. Clean production is required by all industrial fields but is the most important in chemical industry. The Government has made efforts to change the domestic industrial structure to the environmental-friendly structure through developing the research. However, the domestic industry has not yet activated overall except some large companies, which has concretized the activation of clean production. Especially, the medium and small companies are more sluggish due to the inferiority of capital and technology. With recognizing that the main body of clean production is a company, the effort based on the Government and the academic world, without companies' positive, will cannot help being limited in effects. Therefore, it is necessary to trigger the schemes that urge the companies' motivation to show the effects from the support that have concentrated in hardware like technology until now. It seems to be very important that the guidebook for clean production, which a company can easily adopt, is developed and spread. This report provides the guidebook for clean production that managers and engineers can easily understand and approach in a producing field and presents the scheme to promote clean production, for chemical industry that is seriously required clean production. Even if the presented contents are not perfect, they can be applied to the development of the Government's policy and the administrative activities of companies for clean production as a useful data. 53 refs., 5 figs., 30 tabs.

  13. Processing method for cleaning water waste from cement kneader

    International Nuclear Information System (INIS)

    Soda, Kenzo; Fujita, Hisao; Nakajima, Tadashi.

    1990-01-01

    The present invention concerns a method of processing cleaning water wastes from a cement kneader in a case of processing liquid wastes containing radioactive wastes or deleterious materials such as heavy metals by means of cement solidification. Cleaning waste wastes from the kneader are sent to a cleaning water waste tank, in which gentle stirring is applied near the bottom and sludges are retained so as not to be coagulated. Sludges retained at the bottom of the cleaning water waste tank are sent after elapse of a predetermined time and then kneaded with cements. Thus, since the sludges in the cleaning water are solidified with cement, inhomogenous solidification products consisting only of cleaning sludges with low strength are not formed. The resultant solidification product is homogenous and the compression strength thereof reaches such a level as capable of satisfying marine disposal standards required for the solidification products of radioactive wastes. (I.N.)

  14. Steam generators secondary side chemical cleaning at Point Lepreau using the Siemens high temperature process

    International Nuclear Information System (INIS)

    Verma, K.; MacNeil, C.; Odar, S.; Kuhnke, K.

    1997-01-01

    This paper describes the chemical cleaning of the four steam generators at the Point Lepreau facility, which was accomplished as a part of a normal service outage. The steam generators had been in service for twelve years. Sludge samples showed the main elements were Fe, P and Na, with minor amounts of Ca, Mg, Mn, Cr, Zn, Cl, Cu, Ni, Ti, Si, and Pb, 90% in the form of Magnetite, substantial phosphate, and trace amounts of silicates. The steam generators were experiencing partial blockage of broached holes in the TSPs, and corrosion on tube ODs in the form of pitting and wastage. In addition heat transfer was clearly deteriorating. More than 1000 kg of magnetite and 124 kg of salts were removed from the four steam generators

  15. Technological procedure for chemical cleaning prior to re-pyritization of H2O-H2S isotopic exchange installations

    International Nuclear Information System (INIS)

    Stefanescu, I.; Smaranda, D.; Titescu, Gh.

    1996-01-01

    In normal operation the anti-corrosive shielding of the GS installations undergo a slow, irreversible degradation in time so that after 6 - 8 years their protection characteristics break down. In order to put them back in operation the regeneration of anti-corrosive is required. The procedure achieved at ICIS - Rm.Valcea consists in chemical cleaning of the impaired layers and re-pyritization of the interior surface of installations. Chemical cleaning include the following operations: - mechanical cleaning; - water washing; - alkaline washing with sodium hydroxide, tri-sodium phosphate and sodium tri-polyphosphate; - final mechanical cleaning; - neutralizing washing; - chemical cleaning with phosphoric acid solution; - neutralizing washing. After applying this procedure, the surface is prepared for the pyritization regeneration of the anti-corrosive shielding which ensures the prolongation of the equipment service lifetime with another six year period

  16. The importance of chemical components in cleaning agents for the indoor environment

    DEFF Research Database (Denmark)

    Vejrup, Karl Ventzel

    In order to evaluate the importance for the indoor environment of chemical compounds in cleaning agents, the emission of VOCs (Volatile Organic Compounds) from 10 selected cleaning agents and the content of LAS (Linear AlkanbenzeneSulfonate) in dust samples from 7 buildings were investigated.The...... of LAS between smooth floored corridors to carpeted offices, are apparently also of importance for the LAS content in individual rooms.The amounts of LAS found in the dust samples indicated that LAS may be of importance for the indoor environment, but inadequate knowledge about how low concentrations...... investigation of VOC emission from 10 selected cleaning agents showed that it was useful to classify the VOCs into two groups: nonpolar VOCs and polar VOCs.The nonpolar VOCs consisted of several hundred different compounds, mainly terpenes typically used as perfume in cleaning agents. The nonpolar VOC...

  17. Re-establishing filtering capabilities of machined porous beryllium via chemical reduction and cleaning

    International Nuclear Information System (INIS)

    Randall, W.L.

    1975-01-01

    Porous beryllium is furnished in sheets of varying sizes and thickness; it is therefore necessary that it be machined into specified sizes. A chemical reduction and cleaning procedure was devised to remove the disrupted surface, open the sealed pores of the material, and clean entrapped contaminates from the internal structure. Dimensional stability can be closely controlled and material size is of no consequence. (U.S.)

  18. TESTING OF ENHANCED CHEMICAL CLEANING OF SRS ACTUAL WASTE TANK 5F AND TANK 12H SLUDGES

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C.; King, W.

    2011-08-22

    Forty three of the High Level Waste (HLW) tanks at the Savannah River Site (SRS) have internal structures that hinder removal of the last approximately five thousand gallons of waste sludge solely by mechanical means. Chemical cleaning can be utilized to dissolve the sludge heel with oxalic acid (OA) and pump the material to a separate waste tank in preparation for final disposition. This dissolved sludge material is pH adjusted downstream of the dissolution process, precipitating the sludge components along with sodium oxalate solids. The large quantities of sodium oxalate and other metal oxalates formed impact downstream processes by requiring additional washing during sludge batch preparation and increase the amount of material that must be processed in the tank farm evaporator systems and the Saltstone Processing Facility. Enhanced Chemical Cleaning (ECC) was identified as a potential method for greatly reducing the impact of oxalate additions to the SRS Tank Farms without adding additional components to the waste that would extend processing or increase waste form volumes. In support of Savannah River Site (SRS) tank closure efforts, the Savannah River National Laboratory (SRNL) conducted Real Waste Testing (RWT) to evaluate an alternative to the baseline 8 wt. % OA chemical cleaning technology for tank sludge heel removal. The baseline OA technology results in the addition of significant volumes of oxalate salts to the SRS tank farm and there is insufficient space to accommodate the neutralized streams resulting from the treatment of the multiple remaining waste tanks requiring closure. ECC is a promising alternative to bulk OA cleaning, which utilizes a more dilute OA (nominally 2 wt. % at a pH of around 2) and an oxalate destruction technology. The technology is being adapted by AREVA from their decontamination technology for Nuclear Power Plant secondary side scale removal. This report contains results from the SRNL small scale testing of the ECC process

  19. Digital processing of SEM images for the assessment of evaluation indexes of cleaning interventions on Pentelic marble surfaces

    International Nuclear Information System (INIS)

    Moropoulou, A.; Delegou, E.T.; Vlahakis, V.; Karaviti, E.

    2007-01-01

    In this work, digital processing of scanning-electron-microscopy images utilized to assess cleaning interventions applied on the Pentelic marble surfaces of the National Archaeological Museum and National Library in Athens, Greece. Beside mineralogical and chemical characterization that took place by scanning-electron-microscopy with Energy Dispersive X-ray Spectroscopy, the image-analysis program EDGE was applied for estimating three evaluation indexes of the marble micro-structure. The EDGE program was developed by the U.S. Geological Survey for the evaluation of cleaning interventions applied on Philadelphia City Hall. This computer program analyzes scanning-electron-microscopy images of stone specimens cut in cross-section for measuring the fractal dimension of the exposed surfaces, the stone near-surface fracture density, the shape factor (a surface roughness factor) and the friability index which represents the physico-chemical and physico-mechanical stability of the stone surface. The results indicated that the evaluation of the marble surface micro-structure before and after cleaning is achieved by the suggested indexes, while the performance of cleaning interventions on the marble surfaces can be assessed

  20. Decrudding and chemical cleaning of carbon steel components - an evaluation

    International Nuclear Information System (INIS)

    Gaonkar, K.B.; Elayathu, N.S.D.; Shibad, P.R.; Gadiyar, H.S.

    1982-01-01

    Corrosion and accumulation of corrosion products on the surfaces of structural components and plant equipments can cause se vereoperational problems during service. An illustration is the heat exchanger systems in nuclear power stations. Development and standardisation of appropriate chemical cleaning and decontamination procedures and their evaluation hence merit serious consideration. A number of chemical cleaning procedures using formulations based on hydrochloric and citric acid solutions have been examined to study their crud dissolving and derusting ability in addition to the attack on base material. The compositions were chosen: (1) along with complexing agents EDTA and ammonium citrate, (2) with pH control, and (3) with the use of inhibitors acridine, rhodine, hexamine and phenyl-thiourea. The evaluations have been made at 28 and 60 deg C. Rusted carbon steel coupons having a rust of 10-12 mg/cm 2 on the surface have been used for the purpose of the above evaluations. Data on corrosion rates of monel and cupronickel (70:30) in the descaling solutions have also been presented. Results on the above evaluation studies have been discussed. (author)

  1. Substrate Effect on Plasma Clean Efficiency in Plasma Enhanced Chemical Vapor Deposition System

    Directory of Open Access Journals (Sweden)

    Shiu-Ko JangJian

    2007-01-01

    Full Text Available The plasma clean in a plasma-enhanced chemical vapor deposition (PECVD system plays an important role to ensure the same chamber condition after numerous film depositions. The periodic and applicable plasma clean in deposition chamber also increases wafer yield due to less defect produced during the deposition process. In this study, the plasma clean rate (PCR of silicon oxide is investigated after the silicon nitride deposited on Cu and silicon oxide substrates by remote plasma system (RPS, respectively. The experimental results show that the PCR drastically decreases with Cu substrate compared to that with silicon oxide substrate after numerous silicon nitride depositions. To understand the substrate effect on PCR, the surface element analysis and bonding configuration are executed by X-ray photoelectron spectroscopy (XPS. The high resolution inductively coupled plasma mass spectrometer (HR-ICP-MS is used to analyze microelement of metal ions on the surface of shower head in the PECVD chamber. According to Cu substrate, the results show that micro Cu ion and the CuOx bonding can be detected on the surface of shower head. The Cu ion contamination might grab the fluorine radicals produced by NF3 ddissociation in the RPS and that induces the drastic decrease on PCR.

  2. Self Cleaning HEPA Filtration without Interrupting Process Flow

    International Nuclear Information System (INIS)

    Wylde, M.

    2009-01-01

    The strategy of protecting the traditional glass fibre HEPA filtration train from it's blinding contamination and the recovery of dust by the means of self cleaning, pre-filtration is a proven means in the reduction of ultimate disposal volumes and has been used within the Fuel Production Industry. However, there is an increasing demand in nuclear applications requiring elevated operating temperatures, fire resistance, moisture resistance and chemical composition that the existing glass fibre HEPA filtration cannot accommodate, which can be remedied by the use of a metallic HEPA filter media. Previous research (Bergman et al 1997, Moore et al 1992) suggests that the then costs to the DOE, based on a five year life cycle, was $29.5 million for the installation, testing, removal and disposal of glass fibre HEPA filtration trains. Within these costs, $300 was the value given to the filter and $4,450 was given to the peripheral activity. Development of a low cost, cleanable, metallic, direct replacement of the traditional filter train will the clear solution. The Bergman et al work has suggested that a 1000 ft 3 /min, cleanable, stainless HEPA could be commercially available for $5,000 each, whereas the industry has determined that the truer cost of such an item in isolation would be closer to $15,000. This results in a conflict within the requirement between 'low cost' and 'stainless HEPA'. By proposing a system that combines metallic HEPA filtration with the ability to self clean without interrupting the process flow, the need for a tradition HEPA filtration train will be eliminated and this dramatically reduces the resources required for cleaning or disposal, thus presenting a route to reducing ultimate costs. The paper will examine the performance characteristics, filtration efficiency, flow verses differential pressure and cleanability of a self cleaning HEPA grade sintered metal filter element, together with data to prove the contention. (authors)

  3. EPRI/Alberta Research Council Clean Soil Process

    International Nuclear Information System (INIS)

    Spear, C.E.

    1992-12-01

    The EPRI/Alberta Research Council Clean Soil Process can remove hydrocarbon contamination from waste material from manufactured gas plants. The process uses coal as an absorbent to remove hydrocarbons. For petroleum contaminated soils, the process can bring residual concentration of petroleum below 0.1 percent and polycyclic aromatic hydrocarbon (PAH) concentration to 1--5 ppM. For coal tar contaminated soils, the process can reduce tar concentrations to about 0.05-0.5 percent and the PAH concentration to about 10--60 ppM. Additional post-treatment may be required for some precleaned soils. The process yields by-product agglomerates suitable for combustion in industrial boilers. Light hydrocarbons such as benzene are vaporized from the soil, condensed and collected in the Process and disposed of off-site. The Clean Soil Process has been tested at pilot-plant scale. A conceptual design for a 200-tons-per-day plant yielded a capital cost estimated at $3.1 million with a per-ton operating cost of $40

  4. [Assessment of decontamination processes: cleaning, disinfection and sterilization in dental practice in Poland in the years 2011-2012].

    Science.gov (United States)

    Röhm-Rodowald, Ewa; Jakimiak, Bozenna; Chojecka, Agnieszka; Zmuda-Baranowska, Magdalena; Kanclerski, Krzysztof

    2012-01-01

    Effective decontamination of instruments is a key element of infection control and the provision of high quality in dental care. The aim of the study was to evaluate the efficiency of decontamination procedures including cleaning, disinfection and sterilization of re-usable instruments in dental practices in Poland. The efficiency of disinfection and sterilization processes have been evaluated on the results of the questionnaires. The following information were taken into account: setting where disinfection and sterilization had been performed, preparation of dental equipment for sterilization (disinfection, washing and cleaning, packaging), the types of autoclaves and used types of sterilization cycles, routine monitoring and documentation of sterilization processes, treatment of handpieces and the frequency of surface decontamination. Data were collected from 43 dental practices (35 dental offices and 8 clinics). Disinfection and cleaning processes were performed manually in 63% of dental offices and ultrasonic baths were used in 53% of settings. Washer disinfectors were used in 23% of dental practices: in every researched clinic and in a few dental offices. All sterilization processes were performed in steam autoclaves, mainly in small steam sterilizers (81%). Dental handpieces were sterilized in 72% of practices, but only 33% of them performed sterilization in recommended cycle B. Sterilization processes were monitored with chemical indicators in 33% of practices. Biological monitoring of the processes was carried out at different intervals. Incorrect documentation of instruments and surfaces decontamination was recorded in several settings. There is still a need for improvement of decontamination processes in dental practice in Poland. Areas for improvement include: replacement of manual cleaning and disinfection processes with automatic processes, sterilization of dental handpieces after each patient, monitoring of a sterilization process with chemical and

  5. Self-cleaning and surface chemical reactions during hafnium dioxide atomic layer deposition on indium arsenide.

    Science.gov (United States)

    Timm, Rainer; Head, Ashley R; Yngman, Sofie; Knutsson, Johan V; Hjort, Martin; McKibbin, Sarah R; Troian, Andrea; Persson, Olof; Urpelainen, Samuli; Knudsen, Jan; Schnadt, Joachim; Mikkelsen, Anders

    2018-04-12

    Atomic layer deposition (ALD) enables the ultrathin high-quality oxide layers that are central to all modern metal-oxide-semiconductor circuits. Crucial to achieving superior device performance are the chemical reactions during the first deposition cycle, which could ultimately result in atomic-scale perfection of the semiconductor-oxide interface. Here, we directly observe the chemical reactions at the surface during the first cycle of hafnium dioxide deposition on indium arsenide under realistic synthesis conditions using photoelectron spectroscopy. We find that the widely used ligand exchange model of the ALD process for the removal of native oxide on the semiconductor and the simultaneous formation of the first hafnium dioxide layer must be significantly revised. Our study provides substantial evidence that the efficiency of the self-cleaning process and the quality of the resulting semiconductor-oxide interface can be controlled by the molecular adsorption process of the ALD precursors, rather than the subsequent oxide formation.

  6. Superhydrophobic coatings for aluminium surfaces synthesized by chemical etching process

    Directory of Open Access Journals (Sweden)

    Priya Varshney

    2016-10-01

    Full Text Available In this paper, the superhydrophobic coatings on aluminium surfaces were prepared by two-step (chemical etching followed by coating and one-step (chemical etching and coating in a single step processes using potassium hydroxide and lauric acid. Besides, surface immersion time in solutions was varied in both processes. Wettability and surface morphologies of treated aluminium surfaces were characterized using contact angle measurement technique and scanning electron microscopy, respectively. Microstructures are formed on the treated aluminium surfaces which lead to increase in contact angle of the surface (>150°. Also on increasing immersion time, contact angle further increases due to increase in size and depth of microstructures. Additionally, these superhydrophobic coatings show excellent self-cleaning and corrosion-resistant behavior. Water jet impact, floatation on water surface, and low temperature condensation tests assert the excellent water-repellent nature of coatings. Further, coatings are to be found mechanically, thermally, and ultraviolet stable. Along with, these coatings are found to be excellent regeneration ability as verified experimentally. Although aforesaid both processes generate durable and regenerable superhydrophobic aluminium surfaces with excellent self-cleaning, corrosion-resistant, and water-repellent characteristics, but one-step process is proved more efficient and less time consuming than two-step process and promises to produce superhydrophobic coatings for industrial applications.

  7. Overview of shoreline cleaning agents

    International Nuclear Information System (INIS)

    Clayton, J.

    1992-01-01

    Chemical cleaning agents may be used to promote release of stranded oil from shorelines for reasons including biological sensitivity of indigenous fauna and flora to the oil, amenity considerations of the shoreline, or concern about refloating of the oil and subsequent stranding on adjacent shorelines. While use of chemical cleaning agents may be appropriate under proper toxic responses in circumstances, certain limitations should be recognized. The potential for toxic responses in indigenous fauna and flora to the cleaning agents must be considered. Enhanced penetration of oil into permeable shorelines following treatment with chemical cleaning agents also is not desirable. However, if conditions related to toxicity and substrate permeability are determined to be acceptable, the use of chemical cleaning agents for treatment of stranded oil can be considered. Chemical agents for cleaning oiled shorelines can be grouped into three categories: (1) non-surfactant-based solvents, (2) chemical dispersants, and (3) formulations especially designed to release stranded oil from shoreline substrates (i.e., shoreline-cleaning-agents). Depending on the specific circumstances present on an oiled shoreline, it is generally desirable that chemical agents used for cleaning will release oil from shoreline substrate(s) to surface waters. Recovery of the oil can then be accomplished by mechanical procedures such as booming and skimming operations

  8. New, clean handling process introduced to improve cable quality

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, C G

    1990-05-01

    The clean room system introduced by Canada Wire and Cable Limited in its Toronto plant for its cable manufacturing operation is described. While clean room technology is common in the food processing industry, optical and aerospace manufacturing processes, this is the first time it has been applied to wire and cable extrusion in North America. The purpose of the clean compound handling system is to prevent particle contamination in the shielding and cable insulation materials, as part of an effort to prevent premature underground electric cable failures. Two rooms are dedicated to handling different types of insulation compound, two are dedicated to receiving semi-conducting shielding material, and the fifth room functions as an air lock for the two insulation rooms. The atmosphere is highly regulated with programmable logic control. The air supply filters capture 99.97% of all particles 0.3 microns or larger. The system also maintains air temperature, relative humidity and static pressure. The life variability of cross-linked polyethylene primary distribution cable is dependant on five factors: material purity, extra clean compound handling, cable design, manufacturing process, and installation and operation practices. The clean room system is expected to result in cable that is more resistant to water treeing failures. 2 figs.

  9. Occupational radon expositions during cleaning processes of water reservoirs

    International Nuclear Information System (INIS)

    Hingmann, H.; Ehret, V.; Hegenbart, L.; Krieg, K.

    2002-01-01

    According to the new German ''Strahlenschutzverordnung'' (Radiation Protection Directive) the annual dose due to the exposition to radon has to be estimated for employees of water works. This includes employees of service companies. While the job of employees of water works usually covers a broad spectrum of different activities, employees of service companies may spend a considerable amount of time of their total working hours cleaning water reservoirs. This investigation is concerned with this type of employees. The radon exposition of one or more cleaning processes were determined by passive dosimeters. The mean radon concentration was calculated for the duration of the cleaning process. In some cases, members of the project team accompanied cleaning processes and performed stationary radon measurements on site. Sometimes, parallel to the passive dosimeters, electronic dosimeters were used to measure personal exposure. The results - and results from additional laboratory reference measurements - are compared. All results until January 2002 are considered. The project still goes on and will end in summer of 2002. Experiences made during this investigation are described in the end of this report. (orig.)

  10. Method of and apparatus for cleaning garments and soft goods contaminated with nuclear, chemical and/or biological contaminants

    International Nuclear Information System (INIS)

    Fowler, D.E.

    1989-01-01

    A method is described for decontaminating garments, soft good or mixtures thereof contaminated with radioactive particulates, toxin, chemical, and biological contaminants comprising the steps of: (a) depositing contaminated garments, soft goods or mixtures thereof in a cleaning drum; (b) charging the drum with a cleaning solvent in which the chemical contaminants are soluble; (c) agitating the drum during a wash cycle to separate radioactive, toxin, biological particulate matter of mixtures thereof from the garments; (d) draining the drum of the dry cleaning solvent which contains suspended particulate contaminants and dissolved chemical contaminants; (e) contacting the drained solvent with both a neutralizing agent and an oxidizing agent, the neutralizing agent being selected from the group consisting of sodium hydroxide, potassium hydroxide and mixtures thereof and having a concentration greater than one (1.0) normal; (f) rinsing the garments, soft goods or mixtures thereof by circulating clean solvent from a solvent tank through the drum thereby effecting additional removal and flushing of particulate and chemical contaminants; (g) filtering the circulated solvent to remove the particulate material suspended in the solvent prior to addition to the drum; and (h) preferentially adsorbing the chemical contaminants dissolved in the circulated solvent prior to addition to the drum

  11. Alternative, Green Processes for the Precision Cleaning of Aerospace Hardware

    Science.gov (United States)

    Maloney, Phillip R.; Grandelli, Heather Eilenfield; Devor, Robert; Hintze, Paul E.; Loftin, Kathleen B.; Tomlin, Douglas J.

    2014-01-01

    Precision cleaning is necessary to ensure the proper functioning of aerospace hardware, particularly those systems that come in contact with liquid oxygen or hypergolic fuels. Components that have not been cleaned to the appropriate levels may experience problems ranging from impaired performance to catastrophic failure. Traditionally, this has been achieved using various halogenated solvents. However, as information on the toxicological and/or environmental impacts of each came to light, they were subsequently regulated out of use. The solvent currently used in Kennedy Space Center (KSC) precision cleaning operations is Vertrel MCA. Environmental sampling at KSC indicates that continued use of this or similar solvents may lead to high remediation costs that must be borne by the Program for years to come. In response to this problem, the Green Solvents Project seeks to develop state-of-the-art, green technologies designed to meet KSCs precision cleaning needs.Initially, 23 solvents were identified as potential replacements for the current Vertrel MCA-based process. Highly halogenated solvents were deliberately omitted since historical precedents indicate that as the long-term consequences of these solvents become known, they will eventually be regulated out of practical use, often with significant financial burdens for the user. Three solvent-less cleaning processes (plasma, supercritical carbon dioxide, and carbon dioxide snow) were also chosen since they produce essentially no waste stream. Next, experimental and analytical procedures were developed to compare the relative effectiveness of these solvents and technologies to the current KSC standard of Vertrel MCA. Individually numbered Swagelok fittings were used to represent the hardware in the cleaning process. First, the fittings were cleaned using Vertrel MCA in order to determine their true cleaned mass. Next, the fittings were dipped into stock solutions of five commonly encountered contaminants and were

  12. Novel micronized woody biomass process for production of cost-effective clean fermentable sugars.

    Science.gov (United States)

    Fu, Yu; Gu, Bon-Jae; Wang, Jinwu; Gao, Johnway; Ganjyal, Girish M; Wolcott, Michael P

    2018-03-29

    Thermo-chemical pretreatments of biomass typically result in environmental impacts from water use and emission. The degradation byproducts in the resulting sugars can be inhibitory to the activities of enzymes and yeasts. The results of this study showed that combining existing commercial comminution technology can reduce total energy consumption with improved saccharification yield while eliminating chemical use. Impact mill was found to be the most efficient milling for size reduction of forest residual chips from ca. 2 mm to a specific value below 100 µm. The further micronization effectively disrupted the recalcitrance of the woody biomass and produced the highly saccharifiable substrates for downstream processing. In addition, extrusion can be integrated into a clean cellulosic sugar process for further fibrillation in place of the conventional mixing processing. The highest energy efficiency was observed on the impact-milled samples with 0.515 kg sugars kWh -1 . Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. A Facile in Situ and UV Printing Process for Bioinspired Self-Cleaning Surfaces

    Directory of Open Access Journals (Sweden)

    Marina A. González Lazo

    2016-08-01

    Full Text Available A facile in situ and UV printing process was demonstrated to create self-cleaning synthetic replica of natural petals and leaves. The process relied on the spontaneous migration of a fluorinated acrylate surfactant (PFUA within a low-shrinkage acrylated hyperbranched polymer (HBP and its chemical immobilization at the polymer-air interface. Dilute concentrations of 1 wt. % PFUA saturated the polymer-air interface within 30 min, leading to a ten-fold increase of fluorine concentration at the surface compared with the initial bulk concentration and a water contact angle (WCA of 108°. A 200 ms flash of UV light was used to chemically crosslink the PFUA at the HBP surface prior to UV printing with a polydimethylsiloxane (PDMS negative template of red and yellow rose petals and lotus leaves. This flash immobilization hindered the reverse migration of PFUA within the bulk HBP upon contacting the PDMS template, and enabled to produce texturized surfaces with WCA well above 108°. The synthetic red rose petal was hydrophobic (WCA of 125° and exhibited the adhesive petal effect. It was not superhydrophobic due to insufficient concentration of fluorine at its surface, a result of the very large increase of the surface of the printed texture. The synthetic yellow rose petal was quasi-superhydrophobic (WCA of 143°, roll-off angle of 10° and its self-cleaning ability was not good also due to lack of fluorine. The synthetic lotus leaf did not accurately replicate the intricate nanotubular crystal structures of the plant. In spite of this, the fluorine concentration at the surface was high enough and the leaf was superhydrophobic (WCA of 151°, roll-off angle below 5° and also featured self-cleaning properties.

  14. Clean utilization of coal

    International Nuclear Information System (INIS)

    Yueruem, Y.

    1992-01-01

    This volume contains 23 lectures presented at the Advanced Study Institute on 'Chemistry and Chemical Engineering of Catalytic Solid Fuel Conversion for the Production of Clean Synthetic Fuels', which was held at Akcay, Edremit, Turkey, between 21 July and August 3, 1991. Three main subjects: structure and reactivity of coal; cleaning of coal and its products, and factors affecting the environmental balance of energy usage and solutions for the future, were discussed in the Institute and these are presented under six groups in the book: Part 1. Structure and reactivity of coal; Part 2. Factors affecting environmental balance; Part 3. Pre-usage cleaning operations and processes; Part 4. Upgrading of coal liquids and gases; Part 5. Oxygen enriched processes; and Part 6. Probable future solution for energy and pollution problems. Separate abstracts have been prepared for all the lectures

  15. Si-compatible cleaning process for graphene using low-density inductively coupled plasma.

    Science.gov (United States)

    Lim, Yeong-Dae; Lee, Dae-Yeong; Shen, Tian-Zi; Ra, Chang-Ho; Choi, Jae-Young; Yoo, Won Jong

    2012-05-22

    We report a novel cleaning technique for few-layer graphene (FLG) by using inductively coupled plasma (ICP) of Ar with an extremely low plasma density of 3.5 × 10(8) cm(-3). It is known that conventional capacitively coupled plasma (CCP) treatments destroy the planar symmetry of FLG, giving rise to the generation of defects. However, ICP treatment with extremely low plasma density is able to remove polymer resist residues from FLG within 3 min at a room temperature of 300 K while retaining the carbon sp(2)-bonding of FLG. It is found that the carrier mobility and charge neutrality point of FLG are restored to their pristine defect-free state after the ICP treatment. Considering the application of graphene to silicon-based electronic devices, such a cleaning method can replace thermal vacuum annealing, electrical current annealing, and wet-chemical treatment due to its advantages of being a low-temperature, large-area, high-throughput, and Si-compatible process.

  16. Optimization of the process of steel strip perforation and nickel platting for the purpose of elimination of trichloroethylene from the cleaning process of perforated steel strip

    Directory of Open Access Journals (Sweden)

    Petrović Aleksandra B.

    2009-01-01

    Full Text Available In the production of pocket type electrodes for Ni-Cd batteries perforation of proper steel strips and then nickel platting of perforated steel strips were made. In the nickel platting process, the organic solvent, trichloroethylene, has previously been used for cleaning. Due to the carcinogenic nature of trichloroethylene and the many operations previously required during cleaning, it was considered to do cleaning of perforated steel strips without use of the mentioned organic solvent. In the purpose of elimination of trichloroethylene from the cleaning process of perforated steel strips, the tests of perforation of steel strips with use of oils of different viscosity were made. It was shown that there was no dysfunction during the work of the perforation plants, meaning there was no additional heating of the strips, deterring of the steel filings, nor excessive wearing of the perforation apparatus. The perforation percent was the same irrelevant of the viscosity of the used oil. Before being perforated using the oils with different viscosity, the nickel platting steel strips were cleaned in different degreasers (based on NaOH as well as on KOH. It was shown that efficient cleaning without the use of trichloroethylene is possible with the use of oil with smaller viscosity in the perforated steel strips process and the degreaser based on KOH in the cleaning process, before nickel platting. It also appeared that the alkali degreaser based on KOH was more efficient, bath corrections were made less often and the working period of the baths was longer, which all in summary means less quantity of chemicals needed for degreasing of perforated steel strips.

  17. Cleaning and sterilization in biotechnological clean system. Biotechnological clean system no senjo sakkin

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, M.

    1994-02-20

    Despite their usefulness for mankind, many of microorganisms are generally emphasized of the aspect of their harmfulness as decomposable and pathogenic microorganisms, apt to implant people with wrong preconception. Moreover, the food industries have a habitual practice that they leave unexpectedly unclean conditions unattended. This paper indicates such actual circumstances by quoting various examples, and introduces characteristics and test results on commercially available chemicals having excellent cleansing and sterilizing effects. High-pressure and high-temperature sterilization processes fit the purpose of preservation, but secondary contamination may occur in subsequent processing, for example, from the ceiling and walls of a work room, or operators' fingers. Problems exist there that should be considered in biotechnological clean systems. Technologies have been advanced that mix a small amount of chemicals into plastic sheets, wall materials, and floor materials so that their surfaces are kept away from growth of microorganisms for extended periods of time. About 300 kinds of chemicals have been developed, and are available commercially. 3 refs., 8 figs.

  18. Ultrasonic cleaning of electrodes of wire chambers

    International Nuclear Information System (INIS)

    Krasnov, V.A.; Kurepin, A.B.; Razin, V.I.

    1980-01-01

    A technological process of cleaning electrodes and working volume surfaces of wire chambers from contaminations by the simultaneous mechanical action of the energy of ultrasonic oscillations and the chemical action of detergents is discussed. A device for cleaning wire electrodes of proportional chambers of 0.3x0.4 m is described. The device uses two ultrasonic generators with a total power of 0.5 kW. As a detergent use is made of a mixture of ethyl alcohol, gasoline and freon. In the process of cleaning production defects can be detected in the wire chambers which makes it possible to timely remove the defects. Measurements of the surface resistance of fiberglass laminate of printed drift chamber electrodes at a voltage of 2 kV showed that after completing the cleaning process the resistance increases 15-20%

  19. Investigation of the Pulsed Annular Gas Jet for Chemical Reactor Cleaning

    Directory of Open Access Journals (Sweden)

    Zvegintsev Valery Ivanovich

    2012-01-01

    Full Text Available The most economical technology for production of titanium dioxide pigment is plasma-chemical syntheses with the heating of the oxygen. The highlight of the given reaction is formation of a solid phase as a result of interactions between two gases, thus brings the formation of particle deposits on the reactor walls, and to disturbing the normal operation of the technological process. For the solving of the task of reactor internal walls cleaning the pulsed gaseous system was suggested and investigated, which throws circular oxygen jet along surfaces through regular intervals. Study of aerodynamic efficiency of the impulse system was carried by numerical modeling and experimentally with the help of a specially created experimental facility. The distribution of the pulsed flow velocity at the exit of cylindrical reactor was measured. The experimental results have shown that used impulse device creates a pulsed jet with high value of the specified flow rate. It allows to get high velocities that are sufficient for the particle deposits destruction and their removal away. Designed pulsed peelings system has shown high efficiency and reliability in functioning that allows us to recommend it for wide spreading in chemical industry.

  20. Surface modification of titanium membrane by chemical vapor deposition and its electrochemical self-cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.W., E-mail: lynnww@sohu.com [School of Electronic and Information Engieering, Tianjin university, Tianjin, 300072 (China); School of Electronics Information Engieering, Tianjin University of Technology, Tianjin, 300384 (China); Li, J.X. [Tianjin Polytechnic University, Tianjin 300160 (China); Gao, C.Y. [Chinese Peoples Armed Police Forces Academy, Langfang 065000 (China); Chang, M. [School of Electronic and Information Engieering, Tianjin university, Tianjin, 300072 (China); School of Electronics Information Engieering, Tianjin University of Technology, Tianjin, 300384 (China)

    2011-10-15

    Membrane separation is applied widely in many fields, while concentration polarization and membrane fouling, limiting its promotion and application greatly, are the bottlenecks in membrane application. Among which, membrane fouling is irreversible, membrane must be periodically cleaned or even replaced to restore permeability. Membrane cleaning has become one of Key issues in membrane separation areas. Considering incomparable electrochemical advantages of boron-doped diamond (BDD) film electrode over conventional electrode, a new composite membrane Ti/BDD, made by depositing CVD (chemical vapor deposition) boron-doped diamond film on titanium(Ti) membrane to modify porous titanium surface, that can be cleaned electrochemically is proposed. Feasibility of its preparation and application is discussed in this paper. Results shows that based on the unique electrochemical properties of diamond, cleaning level of this composite Ti/BDD membrane is significantly increased, making membrane life and efficiency improved prominently.

  1. Surface modification of titanium membrane by chemical vapor deposition and its electrochemical self-cleaning

    International Nuclear Information System (INIS)

    Li, X.W.; Li, J.X.; Gao, C.Y.; Chang, M.

    2011-01-01

    Membrane separation is applied widely in many fields, while concentration polarization and membrane fouling, limiting its promotion and application greatly, are the bottlenecks in membrane application. Among which, membrane fouling is irreversible, membrane must be periodically cleaned or even replaced to restore permeability. Membrane cleaning has become one of Key issues in membrane separation areas. Considering incomparable electrochemical advantages of boron-doped diamond (BDD) film electrode over conventional electrode, a new composite membrane Ti/BDD, made by depositing CVD (chemical vapor deposition) boron-doped diamond film on titanium(Ti) membrane to modify porous titanium surface, that can be cleaned electrochemically is proposed. Feasibility of its preparation and application is discussed in this paper. Results shows that based on the unique electrochemical properties of diamond, cleaning level of this composite Ti/BDD membrane is significantly increased, making membrane life and efficiency improved prominently.

  2. Significant OH production under surface cleaning and air cleaning conditions: Impact on indoor air quality.

    Science.gov (United States)

    Carslaw, N; Fletcher, L; Heard, D; Ingham, T; Walker, H

    2017-11-01

    We report measurements of hydroxyl (OH) and hydroperoxy (HO 2 ) radicals made by laser-induced fluorescence spectroscopy in a computer classroom (i) in the absence of indoor activities (ii) during desk cleaning with a limonene-containing cleaner (iii) during operation of a commercially available "air cleaning" device. In the unmanipulated environment, the one-minute averaged OH concentration remained close to or below the limit of detection (6.5×10 5  molecule cm -3 ), whilst that of HO 2 was 1.3×10 7  molecule cm -3 . These concentrations increased to ~4×10 6 and 4×10 8  molecule cm -3 , respectively during desk cleaning. During operation of the air cleaning device, OH and HO 2 concentrations reached ~2×10 7 and ~6×10 8  molecule cm -3 respectively. The potential of these OH concentrations to initiate chemical processing is explored using a detailed chemical model for indoor air (the INDCM). The model can reproduce the measured OH and HO 2 concentrations to within 50% and often within a few % and demonstrates that the resulting secondary chemistry varies with the cleaning activity. Whilst terpene reaction products dominate the product composition following surface cleaning, those from aromatics and other VOCs are much more important during the use of the air cleaning device. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. PWR steam generator chemical cleaning, Phase I. Final report

    International Nuclear Information System (INIS)

    Rothstein, S.

    1978-07-01

    United Nuclear Industries (UNI) entered into a subcontract with Consolidated Edison Company of New York (Con Ed) on August 8, 1977, for the purpose of developing methods to chemically clean the secondary side tube to tube support crevices of the steam generators of Indian Point Nos. 1 and 2 PWR plants. This document represents the first reporting on activities performed for Phase I of this effort. Specifically, this report contains the results of a literature search performed by UNI for the purpose of determining state-of-the-art chemical solvents and methods for decontaminating nuclear reactor steam generators. The results of the search sought to accomplish two objectives: (1) identify solvents beyond those proposed at present by UNI and Con Ed for the test program, and (2) confirm the appropriateness of solvents and methods of decontamination currently in use by UNI

  4. Bubble size distribution analysis and control in high frequency ultrasonic cleaning processes

    International Nuclear Information System (INIS)

    Hauptmann, M; Struyf, H; Mertens, P; Heyns, M; Gendt, S De; Brems, S; Glorieux, C

    2012-01-01

    In the semiconductor industry, the ongoing down-scaling of nanoelectronic elements has lead to an increasing complexity of their fabrication. Hence, the individual fabrication processes become increasingly difficult to handle. To minimize cross-contamination, intermediate surface cleaning and preparation steps are inevitable parts of the semiconductor process chain. Here, one major challenge is the removal of residual nano-particulate contamination resulting from abrasive processes such as polishing and etching. In the past, physical cleaning techniques such as megasonic cleaning have been proposed as suitable solutions. However, the soaring fragility of the smallest structures is constraining the forces of the involved physical removal mechanisms. In the case of 'megasonic' cleaningcleaning with ultrasound in the MHz-domain – the main cleaning action arises from strongly oscillating microbubbles which emerge from the periodically changing tensile strain in the cleaning liquid during sonication. These bubbles grow, oscillate and collapse due to a complex interplay of rectified diffusion, bubble coalescence, non-linear pulsation and the onset of shape instabilities. Hence, the resulting bubble size distribution does not remain static but alternates continuously. Only microbubbles in this distribution that show a high oscillatory response are responsible for the cleaning action. Therefore, the cleaning process efficiency can be improved by keeping the majority of bubbles around their resonance size. In this paper, we propose a method to control and characterize the bubble size distribution by means of 'pulsed' sonication and measurements of acoustic cavitation spectra, respectively. We show that the so-obtained bubble size distributions can be related to theoretical predictions of the oscillatory responses of and the onset of shape instabilities for the respective bubbles. We also propose a mechanism to explain the enhancement of both acoustic and cleaning

  5. Generation of dissolved organic matter and byproducts from activated sludge during contact with sodium hypochlorite and its implications to on-line chemical cleaning in MBR.

    Science.gov (United States)

    Cai, Weiwei; Liu, Jiaqi; Zhang, Xiangru; Ng, Wun Jern; Liu, Yu

    2016-11-01

    On-line chemical cleaning of membranes with sodium hypochlorite (NaClO) has been commonly employed for maintaining a constant permeability of membrane bioreactor (MBR) due to its simple and efficient operation. However, activated sludge is inevitably exposed to NaClO during this cleaning process. In spite of the broad applications of on-line chemical cleaning in MBR such as chemical cleaning-in-place (CIP) and chemical enhanced backwash (CEB), little information is currently available for the release of emerging dissolved organic matter (DOM) and byproducts from this prevalent practice. Therefore, in this study, activated sludge suspended in a phosphate buffered saline solution was exposed to different doses of NaClO in order to determine the generation of potential DOM and byproducts. The results showed the occurrence of significant DOM release (up to 24.7 mg/L as dissolved organic carbon) after exposure to NaClO for 30 min. The dominant components of the released DOM were characterized to be humic acid-like as well as protein-like substances by using an excitation-emission matrix fluorescence spectrophotometer. Furthermore, after the contact of activated sludge with NaClO, 19 kinds of chlorinated and brominated byproducts were identified by ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry, eight of which were confirmed and characterized with standard compounds. Many byproducts were found to be halogenated aromatic compounds, including halopyrroles and halo(hydro)benzoquinones, which had been reported to be significantly more toxic than the halogenated aliphatic ones. Consequently, this study offers new insights into the practice of on-line chemical cleaning, and opens up a window to re-examine the current operation of MBR by looking into the generation of micropollutants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. How Clean is Safe? Improving the Effectiveness of Decontamination of Structures and People Following Chemical and Biological Incidents

    Energy Technology Data Exchange (ETDEWEB)

    Vogt (Sorensen), B.M.

    2003-04-03

    This report describes a U.S. Department of Energy, (DOE) Chemical and Biological National Security Program project that sought to establish what is known about decontamination of structures, objects, and people following an exposure to chemical or biological materials. Specifically we sought to identify the procedures and protocols used to determine when and how people or buildings are considered ''clean'' following decontamination. To fulfill this objective, the study systematically examined reported decontamination experiences to determine what procedures and protocols are currently employed for decontamination, the timeframe involved to initiate and complete the decontamination process, how the contaminants were identified, the factors determining when people were (or were not) decontaminated, the problems encountered during the decontamination process, how response efforts of agencies were coordinated, and the perceived social psychological effects on people who were decontaminated or who participated in the decontamination process. Findings and recommendations from the study are intended to aid decision-making and to improve the basis for determining appropriate decontamination protocols for recovery planners and policy makers for responding to chemical and biological events.

  7. Process for cleaning radioactively contaminated metal surfaces

    International Nuclear Information System (INIS)

    Mihram, R.G.; Snyder, G.A.

    1975-01-01

    A process is described for removing radioactive scale from a ferrous metal surface, including the steps of initially preconditioning the surface by contacting it with an oxidizing solution (such as an aqueous solution of an alkali metal permanganate or hydrogen peroxide), then, after removal or decomposition of the oxidizing solution, the metallic surface is contacted with a cleaning solution which is a mixture of a mineral acid and a complexing agent (such as sulfuric acid and oxalic acid), and which preferably contains a corrosion inhibitor. A final step in the process is the treatment of the spent cleaning solution containing radioactive waste materials in solution by adding a reagent selected from the group consisting of calcium hydroxide or potassium permanganate and an alkali metal hydroxide to thereby form easily recovered metallic compounds containing substantially all of the dissolved metals and radioactivity. (auth)

  8. Reactive Ion Etching as Cleaning Method Post Chemical Mechanical Polishing for Phase Change Memory Device

    International Nuclear Information System (INIS)

    Min, Zhong; Zhi-Tang, Song; Bo, Liu; Song-Lin, Feng; Bomy, Chen

    2008-01-01

    In order to improve nano-scale phase change memory performance, a super-clean interface should be obtained after chemical mechanical polishing (CMP) of Ge 2 Sb 2 Te 5 phase change films. We use reactive ion etching (RIE) as the cleaning method. The cleaning effect is analysed by scanning electron microscopy and an energy dispersive spectrometer. The results show that particle residue on the surface has been removed. Meanwhile, Ge 2 Sb 2 Te 5 material stoichiometric content ratios are unchanged. After the top electrode is deposited, current-voltage characteristics test demonstrates that the set threshold voltage is reduced from 13 V to 2.7V and the threshold current from 0.1mA to 0.025mA. Furthermore, we analyse the RIE cleaning principle and compare it with the ultrasonic method

  9. Thermalhydraulic assessment of the Pickering NGS 'B' feed and bleed system for the hot boiler chemical clean (Siemens Process)

    International Nuclear Information System (INIS)

    Lorencez, Carlos M.

    2000-01-01

    The Hot Boiler Chemical Clean (HBCC) process from Siemens, to be used in PNGS, requires that the Heat Transport System (HTS) temperature be maintained in the range 160 to 170 o C for several days. To achieve these thermalhydraulic condition, the core decay power and the pump power of the main circulating pumps in a 3-3 configuration are employed to warm up the HTS from approximately 38 o C to 170 o C. At this point, high Bleed bias is applied to the signal of the HTS pressure controller to provide high Feed and Bleed flows, which are used to control the HTS temperature by means of the Bleed Cooler. To address any concern posed by these infrequently used HTS thermalhydraulic conditions, a detailed thermalhydraulic model of the Feed and Bleed System, that also includes the Gland Supply, Gland Return and Purification systems, was developed for the TUF code to determine the suitability of the Feed and Bleed System to conduct the HBCC. The model was then used to estimate the parameters such as Feed and Bleed flows, valve openings, pressure and temperature distributions throughout the Feed and Bleed System required for the application of HBCC. (author)

  10. TREATMENT TANK CORROSION STUDIES FOR THE ENHANCED CHEMICAL CLEANING PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B.

    2011-08-24

    Radioactive waste is stored in high level waste tanks on the Savannah River Site (SRS). Savannah River Remediation (SRR) is aggressively seeking to close the non-compliant Type I and II waste tanks. The removal of sludge (i.e., metal oxide) heels from the tank is the final stage in the waste removal process. The Enhanced Chemical Cleaning (ECC) process is being developed and investigated by SRR to aid in Savannah River Site (SRS) High-Level Waste (HLW) as an option for sludge heel removal. Corrosion rate data for carbon steel exposed to the ECC treatment tank environment was obtained to evaluate the degree of corrosion that occurs. These tests were also designed to determine the effect of various environmental variables such as temperature, agitation and sludge slurry type on the corrosion behavior of carbon steel. Coupon tests were performed to estimate the corrosion rate during the ECC process, as well as determine any susceptibility to localized corrosion. Electrochemical studies were performed to develop a better understanding of the corrosion mechanism. The tests were performed in 1 wt.% and 2.5 wt.% oxalic acid with HM and PUREX sludge simulants. The following results and conclusions were made based on this testing: (1) In 1 wt.% oxalic acid with a sludge simulant, carbon steel corroded at a rate of less than 25 mpy within the temperature and agitation levels of the test. No susceptibility to localized corrosion was observed. (2) In 2.5 wt.% oxalic acid with a sludge simulant, the carbon steel corrosion rates ranged between 15 and 88 mpy. The most severe corrosion was observed at 75 C in the HM/2.5 wt.% oxalic acid simulant. Pitting and general corrosion increased with the agitation level at this condition. No pitting and lower general corrosion rates were observed with the PUREX/2.5 wt.% oxalic acid simulant. The electrochemical and coupon tests both indicated that carbon steel is more susceptible to localized corrosion in the HM/oxalic acid environment than

  11. Treatment Tank Corrosion Studies For The Enhanced Chemical Cleaning Process

    International Nuclear Information System (INIS)

    Wiersma, B.

    2011-01-01

    Radioactive waste is stored in high level waste tanks on the Savannah River Site (SRS). Savannah River Remediation (SRR) is aggressively seeking to close the non-compliant Type I and II waste tanks. The removal of sludge (i.e., metal oxide) heels from the tank is the final stage in the waste removal process. The Enhanced Chemical Cleaning (ECC) process is being developed and investigated by SRR to aid in Savannah River Site (SRS) High-Level Waste (HLW) as an option for sludge heel removal. Corrosion rate data for carbon steel exposed to the ECC treatment tank environment was obtained to evaluate the degree of corrosion that occurs. These tests were also designed to determine the effect of various environmental variables such as temperature, agitation and sludge slurry type on the corrosion behavior of carbon steel. Coupon tests were performed to estimate the corrosion rate during the ECC process, as well as determine any susceptibility to localized corrosion. Electrochemical studies were performed to develop a better understanding of the corrosion mechanism. The tests were performed in 1 wt.% and 2.5 wt.% oxalic acid with HM and PUREX sludge simulants. The following results and conclusions were made based on this testing: (1) In 1 wt.% oxalic acid with a sludge simulant, carbon steel corroded at a rate of less than 25 mpy within the temperature and agitation levels of the test. No susceptibility to localized corrosion was observed. (2) In 2.5 wt.% oxalic acid with a sludge simulant, the carbon steel corrosion rates ranged between 15 and 88 mpy. The most severe corrosion was observed at 75 C in the HM/2.5 wt.% oxalic acid simulant. Pitting and general corrosion increased with the agitation level at this condition. No pitting and lower general corrosion rates were observed with the PUREX/2.5 wt.% oxalic acid simulant. The electrochemical and coupon tests both indicated that carbon steel is more susceptible to localized corrosion in the HM/oxalic acid environment than

  12. Chemical cleaning and decontamination of equipments in Rajasthan Atomic Power Station-2, Kota, NPCIL

    International Nuclear Information System (INIS)

    Pal, P.K.; Saini, S.L.

    2008-01-01

    Heat exchanger of End Shield Cooling System of RAPS-2 made up of 70:30 cupronickel was cleaned with a cleaning solution containing 5% sulphamic acid for periods of around 10 hours at a temperature of 60 deg C. The cleaning was attempted to remove the deposit inside the tube of heat exchanger to make a path of the probe to go inside the tube for eddy current testing for measurement of wall thinning. During the campaign 20 kg of CaCO 3 and 5 kg of SiO 2 were removed. Pre-cooler of heat transport system of RAPS-2 made up of monel was cleaned with a cleaning solution containing 5% citric acid, 1% ascorbic acid and 1% NTA at 50-60 deg C temperature for about 20 hours. The cleaning was attempted to remove the deposit inside the tube of pre cooler to make a path of the probe to go inside the tube for eddy current testing for measurement of wall thinning. For the pre-cooler a decontamination factor of 2 to 3 was obtained. The paper describes about the analysis of the deposit, the cleaning process, and schematic diagram of the process. (author)

  13. Hot gas cleaning, a targeted project

    Energy Technology Data Exchange (ETDEWEB)

    Romey, I. [University of Essen, Essen (Germany)

    1998-11-01

    Advanced hot gas cleaning systems will play a key role in future integrated combined cycle technologies. IGCC demonstration plants in operation or under construction are at present equipped with conventional wet gas scrubbing and cleaning systems. Feasibility studies for those IGCC plants have shown that the total efficiency of the processes can be improved using hot gas cleaning systems. However, this technology has not been developed and tested at a technical scale. Six well-known European industrial companies and research centres jointly worked together since January 1996 on a Targeted Project `Hot Gas Cleaning` to investigate and develop new hot gas cleaning systems for advanced clean coal power generation processes. In addition project work on chemical analysis and modelling was carried out in universities in England and Germany. The latest main findings were presented at the workshop. The main project aims are summarised as follows: to increase efficiency of advanced power generation processes; to obtain a reduction of alkalis and environmental emissions e.g. SO{sub 2}, NO{sub x}, CO{sub 2} and dust; and to develop the design basis for future industrial plants based on long-term operation of laboratory, pilot and demo-plants. To cover a range of possible process routes for future hot gas cleaning systems the following research programme is under investigation: removal of trace elements by different commercial and self developed sorbents; gas separation by membranes; separation of gas turbine relevant pollutants by hot filter dust and; H{sub 2}S removal and gas dedusting at high temperatures. 13 figs.

  14. Use of a fluorescent chemical as a quality indicator for a hospital cleaning program.

    Science.gov (United States)

    Blue, Jennifer; O'Neill, Cindy; Speziale, Paul; Revill, Jeff; Ramage, Lee; Ballantyne, Lisa

    2008-01-01

    Hamilton Health Sciences is a large teaching hospital with over 1,000 beds and consists of three acute care sites, one Regional Cancer Center and two Rehabilitation/Chronic Care facilities. An environmental cleaning pilot project was initiated at the acute care Henderson site, following an outbreak of vancomycin-resistant Enterococcus (VRE). Healthcare-associated infections (HAI) due to antibiotic-resistant organisms are increasing in Southern Ontario. Environmental cleaning plays a key role in eradicating resistant organisms that live in hospital environments, thereby helping to reduce HAIs. The environmental cleaning practices on the Orthopaedic Unit were identified as a contributing factor to the VRE outbreak after visual assessments were completed using a Brevis GlitterBug product, a chemical that fluoresces under an ultraviolet (UV) lamp. These findings led to a hospital-wide cleaning improvement initiative on all units except critical care areas. The GlitterBug potion was employed by Infection Control and Customer Support Services (CSS) as a tool to evaluate the daily cleaning of patient washrooms as well as discharge cleaning of contact precaution isolation rooms. Over a four-week period, the GlitterBug potion was applied to seven frequently touched standard targets in randomly selected patient bathrooms on each unit and 14 frequently touched targets prior to cleaning in the rooms used for isolation. The targets were then evaluated using the UV lamp to detect objects that were not cleaned and the results were recorded on a standardized form. The rate of targets cleaned versus the targets missed was calculated. The overall rate for daily cleaning of bathrooms and cleaning of isolation rooms was poor with only 23% of the targets cleaned. Based on these findings, several interventions were implemented. This resulted in a significant improvement in cleaning practices during the pilot project. Greater than 80% of the targets were cleaned compared to the baseline

  15. FY1995 development of a clean CVD process by evaluation and control of gas phase nucleation phenomena; 1995 nendo kisokaku seisei gensho no hyoka to seigyo ni yoru clean CVD process no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The purpose of this study is to develop a high-rate and clean chemical vapor deposition (CVD) process as a breakthrough technique to overcome the problems that particles generated in the gas phase during CVD process for preparation of functional thin films cause reduced product yield and deterioration of the films. In the CVD process proposed here, reactant gas and generated particles are electrically charged to control the motion of them with an electric field. In this study, gas-phase nucleation phenomena are evaluated both theoretically and experimentally. A high-rate, ionized CVD method is first developed, in which reactant gas and generated particles are charged with negative ions generated from a radioisotope source and the UV/photoelectron method, and the motion of the charged gas and particles is controlled with an electric field. Charging and transport processes of fine particles are then investigated experimentally and theoretically to develop a clean CVD method in which generated particles are removed with the electric forces. As a result, quantitative evaluation of the charging and transport process was made possible. We also developed devices for measuring the size distribution and concentration of fine particles in low pressure gas such as those found in plasma CVD processes. In addition, numerical simulation and experiments in this study for a TEOS/O{sub 3} CVD process to prepare thin films could determine reaction rates which have not been known so far and give information on selecting good operation conditions for the process. (NEDO)

  16. Extending CO2 cryogenic aerosol cleaning for advanced optical and EUV mask cleaning

    Science.gov (United States)

    Varghese, Ivin; Bowers, Charles W.; Balooch, Mehdi

    2011-11-01

    Cryogenic CO2 aerosol cleaning being a dry, chemically-inert and residue-free process is used in the production of optical lithography masks. It is an attractive cleaning option for the mask industry to achieve the requirement for removal of all printable soft defects and repair debris down to the 50nm printability specification. In the technique, CO2 clusters are formed by sudden expansion of liquid from high to almost atmospheric pressure through an optimally designed nozzle orifice. They are then directed on to the soft defects or debris for momentum transfer and subsequent damage free removal from the mask substrate. Unlike aggressive acid based wet cleaning, there is no degradation of the mask after processing with CO2, i.e., no critical dimension (CD) change, no transmission/phase losses, or chemical residue that leads to haze formation. Therefore no restriction on number of cleaning cycles is required to be imposed, unlike other cleaning methods. CO2 aerosol cleaning has been implemented for several years as full mask final clean in production environments at several state of the art mask shops. Over the last two years our group reported successful removal of all soft defects without damage to the fragile SRAF features, zero adders (from the cleaning and handling mechanisms) down to a 50nm printability specification. In addition, CO2 aerosol cleaning is being utilized to remove debris from Post-RAVE repair of hard defects in order to achieve the goal of no printable defects. It is expected that CO2 aerosol cleaning can be extended to extreme ultraviolet (EUV) masks. In this paper, we report advances being made in nozzle design qualification for optimum snow properties (size, velocity and flux) using Phase Doppler Anemometry (PDA) technique. In addition the two new areas of focus for CO2 aerosol cleaning i.e. pellicle glue residue removal on optical masks, and ruthenium (Ru) film on EUV masks are presented. Usually, the residue left over after the pellicle

  17. 7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

    Science.gov (United States)

    2010-01-01

    ... quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required under... seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for... pertaining to such seed show that it is “Seed for processing,” or, if the seed is in containers and in...

  18. 7 CFR 361.8 - Cleaning of imported seed and processing of certain Canadian-origin screenings.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Cleaning of imported seed and processing of certain... SCREENINGS UNDER THE FEDERAL SEED ACT § 361.8 Cleaning of imported seed and processing of certain Canadian... compliance agreement for the cleaning of imported seed or processing of otherwise prohibited screenings from...

  19. Alternative Chemical Cleaning Methods for High Level Waste Tanks: Actual Waste Testing with SRS Tank 5F Sludge

    Energy Technology Data Exchange (ETDEWEB)

    King, William D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hay, Michael S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-08-30

    Solubility testing with actual High Level Waste tank sludge has been conducted in order to evaluate several alternative chemical cleaning technologies for the dissolution of sludge residuals remaining in the tanks after the exhaustion of mechanical cleaning and sludge sluicing efforts. Tests were conducted with archived Savannah River Site (SRS) radioactive sludge solids that had been retrieved from Tank 5F in order to determine the effectiveness of an optimized, dilute oxalic/nitric acid cleaning reagent toward dissolving the bulk non-radioactive waste components. Solubility tests were performed by direct sludge contact with the oxalic/nitric acid reagent and with sludge that had been pretreated and acidified with dilute nitric acid. For comparison purposes, separate samples were also contacted with pure, concentrated oxalic acid following current baseline tank chemical cleaning methods. One goal of testing with the optimized reagent was to compare the total amounts of oxalic acid and water required for sludge dissolution using the baseline and optimized cleaning methods. A second objective was to compare the two methods with regard to the dissolution of actinide species known to be drivers for SRS tank closure Performance Assessments (PA). Additionally, solubility tests were conducted with Tank 5 sludge using acidic and caustic permanganate-based methods focused on the “targeted” dissolution of actinide species.

  20. Substitution of Organic Solvents in Selected Industrial Cleaning Processes

    DEFF Research Database (Denmark)

    Jacobsen, Thomas; Rasmussen, Pia Brunn

    1997-01-01

    Volatile organic solvents (VOC)are becoming increasingly unwanted in industrial processes. Substitution of VOC with non-volatile, low-toxic compounds is a possibility to reduce VOC-use. It has been successfully demonstrated, that organic solvents used in cleaning processes in sheet offset printing...

  1. Development of Statistical Process Control Methodology for an Environmentally Compliant Surface Cleaning Process in a Bonding Laboratory

    Science.gov (United States)

    Hutchens, Dale E.; Doan, Patrick A.; Boothe, Richard E.

    1997-01-01

    Bonding labs at both MSFC and the northern Utah production plant prepare bond test specimens which simulate or witness the production of NASA's Reusable Solid Rocket Motor (RSRM). The current process for preparing the bonding surfaces employs 1,1,1-trichloroethane vapor degreasing, which simulates the current RSRM process. Government regulations (e.g., the 1990 Amendments to the Clean Air Act) have mandated a production phase-out of a number of ozone depleting compounds (ODC) including 1,1,1-trichloroethane. In order to comply with these regulations, the RSRM Program is qualifying a spray-in-air (SIA) precision cleaning process using Brulin 1990, an aqueous blend of surfactants. Accordingly, surface preparation prior to bonding process simulation test specimens must reflect the new production cleaning process. The Bonding Lab Statistical Process Control (SPC) program monitors the progress of the lab and its capabilities, as well as certifies the bonding technicians, by periodically preparing D6AC steel tensile adhesion panels with EA-91 3NA epoxy adhesive using a standardized process. SPC methods are then used to ensure the process is statistically in control, thus producing reliable data for bonding studies, and identify any problems which might develop. Since the specimen cleaning process is being changed, new SPC limits must be established. This report summarizes side-by-side testing of D6AC steel tensile adhesion witness panels and tapered double cantilevered beams (TDCBs) using both the current baseline vapor degreasing process and a lab-scale spray-in-air process. A Proceco 26 inches Typhoon dishwasher cleaned both tensile adhesion witness panels and TDCBs in a process which simulates the new production process. The tests were performed six times during 1995, subsequent statistical analysis of the data established new upper control limits (UCL) and lower control limits (LCL). The data also demonstrated that the new process was equivalent to the vapor

  2. Textile Dry Cleaning Using Carbon Dioxide : Process, Apparatus and Mechanical Action

    NARCIS (Netherlands)

    Sutanto, S.

    2014-01-01

    Fabrics that are sensitive to water, may wrinkle or shrink when washed in regular washing machines and are usually cleaned by professional dry cleaners. Dry cleaning is a process of removing soils from substrate, in this case textile, using a non-aqueous solvent. The most common solvent in

  3. The AREVA C3 concept. Customized chemical cleaning as an essential part of steam generator asset management

    International Nuclear Information System (INIS)

    Weiss, Steffen

    2011-01-01

    As the nuclear industry moves forward and the world's power demand increases, the continued safe, reliable, and efficient operation of existing plants has become indispensable. For these plants asset management is an essential factor. A crucial part of the plant assets are the steam generators (SG). Not only that the SG tubes are by far the largest boundary between the primary and secondary sides, they are also instrumental in the overall performance of the plant. The main concern for operational lifetime is tube degradation due to either ID or OD corrosion. At the secondary side, sludge and corrosion products accumulate in the SG resulting in the buildup of secondary side deposits. Such deposits can negatively affect the SG performance in different ways, not only by reduction of the heat transfer rates and, thus, by reducing the efficiency of the SG but also as cause or promotion of different types of corrosion phenomena. The cleanliness of the secondary side of SG is of essential interest to all utilities. There is not just one solution for SG asset optimization. The utilities must weigh the pros and cons of SG cleaning, with the associated impact on outage time and cost, versus the potential benefits. Each plant that considers a SG chemical cleaning has different objectives and goals. AREVA has developed the C 3 (Customized Chemical Cleaning - or in short 'C cubed') concept in order to provide the utility with a chemical cleaning method that is tailored to the needs of the individual units and that addresses them directly. (orig.)

  4. The successful of finite element to invent particle cleaning system by air jet in hard disk drive

    Science.gov (United States)

    Jai-Ngam, Nualpun; Tangchaichit, Kaitfa

    2018-02-01

    Hard Disk Drive manufacturing has faced very challenging with the increasing demand of high capacity drives for Cloud-based storage. Particle adhesion has also become increasingly important in HDD to gain more reliability of storage capacity. The ability to clean on surfaces is more complicated in removing such particles without damaging the surface. This research is aim to improve the particle cleaning in HSA by using finite element to develop the air flow model then invent the prototype of air cleaning system to remove particle from surface. Surface cleaning by air pressure can be applied as alternative for the removal of solid particulate contaminants that is adhering on a solid surface. These technical and economic challenges have driven the process development from traditional way that chemical solvent cleaning. The focus of this study is to develop alternative way from scrub, ultrasonic, mega sonic on surface cleaning principles to serve as a foundation for the development of new processes to meet current state-of-the-art process requirements and minimize the waste from chemical cleaning for environment safety.

  5. Characterization and electrolytic cleaning of poly(methyl methacrylate) residues on transferred chemical vapor deposited graphene

    Science.gov (United States)

    Sun, Jianbo; Finklea, Harry O.; Liu, Yuxin

    2017-03-01

    Poly(methyl methacrylate) (PMMA) residue has long been a critical challenge for practical applications of the transferred chemical vapor deposited (CVD) graphene. Thermal annealing is empirically used for the removal of the PMMA residue; however experiments imply that there are still small amounts of residues left after thermal annealing which are hard to remove with conventional methods. In this paper, the thermal degradation of the PMMA residue upon annealing was studied by Raman spectroscopy. The study reveals that post-annealing residues are generated by the elimination of methoxycarbonyl side chains in PMMA and are believed to be absorbed on graphene via the π-π interaction between the conjugated unsaturated carbon segments and graphene. The post-annealing residues are difficult to remove by further annealing in a non-oxidative atmosphere due to their thermal and chemical stability. An electrolytic cleaning method was shown to be effective in removing these post-annealing residues while preserving the underlying graphene lattice based on Raman spectroscopy and atomic force microscopy studies. Additionally, a solution-gated field effect transistor was used to study the transport properties of the transferred CVD graphene before thermal annealing, after thermal annealing, and after electrolytic cleaning, respectively. The results show that the carrier mobility was significantly improved, and that the p-doping was reduced by removing PMMA residues and post-annealing residues. These studies provide a more in-depth understanding on the thermal annealing process for the removal of the PMMA residues from transferred CVD graphene and a new approach to remove the post-annealing residues, resulting in a residue-free graphene.

  6. Nondestructive evaluation of the QT on the SG tubes affected by chemical cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ki Seok Shin; Cheon, Keun Young; Kim, Wang Bae [Central Research Institute, Daejeon (Korea, Republic of); Min, Kyong Mahn [UMI, Daejeon (Korea, Republic of)

    2012-10-15

    The major mechanisms of flaws detected on the currently operating steam generator(SG) tubes are wear and stress corrosion cracking(SCC) defects. Wear defect has continuously occurred in the upper tube bundle imposed to the flow induced vibration at the interaction between tube and its support structure. Meanwhile, SCC has been formed by a variety of mixed mode, such as the corrosion susceptible material, residual stress and secondary side chemical environment of the SG tubes. Recently, corrosion related defects were detected in the domestic OPR 1000 model SG tubes especially in the egg crate tube support plate(TSP), as a form of axially oriented outer diameter stress corrosion cracking (ODSCC). Therefore, the need to take corrective measures against the corrosion defects is required and various studies have been conducted to clarify the main causes of the defects. In general, as a representing SG tube materials, Ni based alloy 600 tubes have been widely applied and also adversely shown weak properties on the corrosion cracking resistivity. According to the studies on the factors developing corrosion cracking, densely accumulated sludge pile on the secondary side of the SG tubes have been mainly attributed to the formation of the corrosion defects. Therefore, it is imperative to secure applicable and efficient sludge removal process. In this paper, the chemical cleaning processes to dissolve and remove the sludge, thus promote the integrity of the SG tubes were introduced and eddy current testing(ECT) results on the pre cracked SG tubes to determine the effectiveness of those processes were represented as well.

  7. Carbon dioxide nucleation as a novel cleaning method for ultrafiltration membranes

    KAUST Repository

    Al Ghamdi, Mohanned

    2016-12-08

    The use of low-pressure membranes, mainly ultrafiltration (UF), has emerged in the last decade and began to show acceptance as a novel pretreatment process for seawater reverse osmosis (SWRO) desalination. This is mainly due to the superior water quality provided by these membranes, in addition to reduction in chemicals consumption compared to conventional methods. However, membrane fouling remains the main drawback of this technology. Therefore, frequent cleaning of these membranes is required to maintain water flux and its quality. Usually, after a series of backwash using UF permeate chemical cleaning is required under some conditions to fully recover the operating flux. Frequent chemical cleaning will probably decrease the life time of the membrane, increase costs, and will have some effects on the environment. The new cleaning method proposed in this study consists of using a solution saturated with carbon dioxide (CO2) to clean UF membranes. Under the drop in pressure, this solution will become in a supersaturated state and bubbles will start to nucleate on the surface of the membrane and its pores from this solution resulting in the removal of the fouling material deposited on the membrane. Different compositions of fouling solutions including the use of organic compounds such as sodium alginate and colloidal 5 silica with different concentrations were studied using synthetic seawater with different concentrations. This cleaning method was then compared to the backwash using Milli-Q water and showed an improved performance compared to it. An operational modification to this cleaning technique was then investigated which includs a series of sudden pressure drop during the backwash process. This enhanced technique showed an even better performance in cleaning the membrane, especially at severe fouling conditions. In most cases, the membrane permeability was fully recovered even at harsh conditions where conventional backwash failed to maintain a stable

  8. Separation of mercury in industrial processes of Polish hard steam coals cleaning

    Directory of Open Access Journals (Sweden)

    Wierzchowski Krzysztof

    2016-01-01

    Full Text Available Coal use is regarded as one of main sources of anthropogenic propagation of mercury in the environment. The coal cleaning is listed among methods of the mercury emission reduction. The article concerns the statistical assessment of mercury separation between coal cleaning products. Two industrial processes employed in the Polish coal preparation plants are analysed: coal cleaning in heavy media vessels and coal cleaning in jigs. It was found that the arithmetic mean mercury content in coarse and medium coal size fractions for clean coal from heavy media vessels, amounts 68.9 μg/kg, and most of the results lay below the mean value, while for rejects it amounts 95.5 μg/kg. It means that it is for around 25 μg/kg greater than in the clean coal. The arithmetic mean mercury content in raw coal smalls amounts around 118 mg/kg. The cleaning of smalls in jigs results in clean coal and steam coal blends characterized by mean mercury content 96.8 μg/kg and rejects with mean mercury content 184.5 μg/kg.

  9. Solar photocatalytic cleaning of polluted water

    International Nuclear Information System (INIS)

    Bockelmann, D.

    1994-01-01

    Alternatively to biological, physical and chemical methods of waste water cleaning, photocatalysis can be employed. In this residue-free method, titanium dioxide particles are brought into contact with polluted water as photocatalysts. Under UV irradiation at wave-lengths below 400 nm, change carriers are generated in the semiconductor particles that act so intensely oxidizing as to completely degrade almost all organic pollutants in waste water. In this process, the ultra-violet part of the solar spectrum can be harnessed to generate oxidation equivalents. Thus, solar photocatalytic waste water cleaning is excellently suited for developing countries. (BWI) [de

  10. Self Cleaning High Efficiency Particulate Air (HEPA) Filtration without Interrupting Process Flow - 59347

    International Nuclear Information System (INIS)

    Chadwick, Chris

    2012-01-01

    The strategy of protecting the traditional glass fibre HEPA filtration train from it's blinding contamination and the recovery of dust by the means of self cleaning, pre-filtration is a proven means in the reduction of ultimate disposal volumes and has been used within the Fuel Production Industry. However, there is an increasing demand in nuclear applications requiring elevated operating temperatures, fire resistance, moisture resistance and chemical composition that the existing glass fibre HEPA filtration cannot accommodate, which can be remedied by the use of a metallic HEPA filter media. Previous research suggests that the then costs to the Department of Energy (DOE), based on a five year life cycle, was $29.5 million for the installation, testing, removal and disposal of glass fibre HEPA filtration trains. Within these costs, $300 was the value given to the filter and $4, 450 was given to the peripheral activity. Development of a low cost, cleanable, metallic, direct replacement of the traditional filter train will the clear solution. The Bergman et al work has suggested that a 1000 ft 3 /min, cleanable, stainless HEPA could be commercially available for $5, 000 each, whereas the industry has determined that the truer cost of such an item in isolation would be closer to $15, 000. This results in a conflict within the requirement between 'low cost' and 'stainless HEPA'. By proposing a system that combines metallic HEPA filtration with the ability to self clean without interrupting the process flow, the need for a tradition HEPA filtration train will be eliminated and this dramatically reduces the resources required for cleaning or disposal, thus presenting a route to reducing ultimate costs. The paper will examine the performance characteristics, filtration efficiency, flow verses differential pressure and cleanability of a self cleaning HEPA grade sintered metal filter element, together with data to prove the contention. (authors)

  11. Determination of a cleaning and decontamination process using solvents

    International Nuclear Information System (INIS)

    Boutot, P.; Schipfer, P.

    1967-03-01

    This work has been carried out on samples of the white cotton serge material of which most of the working overalls of the Nuclear Research Centre are made. The aims are: - to determine,from the decontamination and cleaning points of view, the efficiency of various solvents (white-spirit, trichloroethylene, perchlorethylene and tri-chloro-trifluoroethane) and the role of additives likely to improve the treatment; - to control the textile from the wear and shrinkage points of view; - to try to develop a basic cleaning and decontamination process as a function of the possibilities of each solvent considered. (authors) [fr

  12. Optimizing a cleaning process for multilayer-dielectric- (MLD) diffraction gratings

    Energy Technology Data Exchange (ETDEWEB)

    Ashe, B. [Univ. of Rochester, NY (United States); Giacofei, C. [Univ. of Rochester, NY (United States); Myhre, G. [Univ. of Rochester, NY (United States); Schmid, A. W. [Univ. of Rochester, NY (United States)

    2007-12-20

    An essential component for the OMEGA EP short-pulse petawatt laser system is the grating compressor chamber (GCC). This large (12,375 ft3) vacuum chamber contains critical optics where laser-pulse compression is performed at the output of the system on two 40-cm-sq-aperture, IR (1054-nm) laser beams. Critical to this compression, within the GCC, are four sets of tiled multilayer-dielectric- (MLD) diffraction gratings that provide the capability for producing 2.6-kJ output IR energy per beam at 10 ps. The primary requirements for these large-aperture (43-cm × 47-cm) gratings are diffraction efficiencies greater than 95%, peak-to-valley wavefront quality of less than λ/10 waves, and laser-induced-damage thresholds greater than 2.7 J/cm2 at 10-ps measured beam normal. Degradation of the grating laser-damage threshold due to adsorption of contaminants from the manufacturing process must be prevented to maintain system performance. In this paper we discuss an optimized cleaning process to achieve the OMEGA EP requirements. The fabrication of MLD gratings involves processes that utilize a wide variety of both organic materials (photoresist processes) and inorganic materials (metals and metal oxides) that can affect the final cleaning process. Finally, a number of these materials have significant optical absorbance; therefore, incomplete cleaning of these residues may result in the MLD gratings experiencing laser damage.

  13. Development of advanced coal cleaning process; Kodo sekitan kaishitsu gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Osaka, S [Center for Coal Utilization, Japan, Tokyo (Japan); Akimoto, A; Yamashita, T [Idemitsu Kosan Co. Ltd., Tokyo (Japan)

    1996-09-01

    This paper aims to develop a clean coal production process which excellently removes environmental pollutant, is low-costed, and need no particular systems for distribution of products. The result of the development was described paying attention to column flotation which is a technology to high-efficiently select particulate regions, particulate heavy media cyclone, magnetic separation, and the basic design of the process into which those above were integrated. The two-stage selection process, which is an integration of column flotation and particulate heavy media cyclone into the conventional coal preparation equipment, can produce low-ash clean coal at high separation efficiency and also suppress the rise in processing cost. This process was also effective for removal of sulfur content and trace metal elements. The use of clean coal at power plant can be effective for not only the reduction in ash treatment amount, but the aspect of boiler operation characteristics such as heat transfer efficiency of boiler furnace wall, ash related troubles, loads of electrostatic precipitator, loads of flue gas desulfurization facilities. 17 figs., 5 tabs.

  14. EM-31 Alternative And Enhanced Chemical Cleaning Program For Sludge Heel Removal - 11220

    International Nuclear Information System (INIS)

    King, W.; Hay, M.; Wiersma, B.; Pennebaker, F.

    2010-01-01

    Mixtures of oxalic acid with nitric acid have been shown to be superior to oxalic acid alone for the dissolution of iron-rich High Level Waste sludge heels. Optimized conditions resulting in minimal oxalate usage and stoichiometric iron dissolution (based on added oxalate ion) have been determined for hematite (a primary sludge iron phase) in oxalic/nitric acid mixtures. The acid mixtures performed better than expected based on the solubility of hematite in the individual acids through a synergistic effect in which the preferred 1:1 Fe:oxalate complex is formed. This allows for the minimization of oxalate additions to the waste stream. Carbon steel corrosion rates were measured in oxalic/nitric acid mixtures to evaluate the impacts of chemical cleaning with these solutions on waste tank integrity. Manageable corrosion rates were observed in the concentration ranges of interest for an acid contact timescale of 1 month. Kinetics tests involving hematite and gibbsite (a primary sludge aluminum phase) have confirmed that (ge)90% solids dissolution occurs within 3 weeks. Based on these results, the chemical cleaning conditions recommended to promote minimal oxalate usage and manageable corrosion include: 0.5 wt. % oxalic acid/0.175 M nitric acid mixture, 50 C, 2-3 week contact time with agitation.

  15. Proceedings of the 21st DOE/NRC Nuclear Air Cleaning Conference

    International Nuclear Information System (INIS)

    First, M.W.; Harvard Univ., Boston, MA

    1991-02-01

    Separate abstracts have been prepared for the papers presented at the meeting on nuclear facility air cleaning technology in the following specific areas of interest: air cleaning technologies for the management and disposal of radioactive wastes; Canadian waste management program; radiological health effects models for nuclear power plant accident consequence analysis; filter testing; US standard codes on nuclear air and gas treatment; European community nuclear codes and standards; chemical processing off-gas cleaning; incineration and vitrification; adsorbents; nuclear codes and standards; mathematical modeling techniques; filter technology; safety; containment system venting; and nuclear air cleaning programs around the world. (MB)

  16. 16th DOE nuclear air cleaning conference: proceedings

    International Nuclear Information System (INIS)

    First, M.W.

    1981-02-01

    Major topics discussed during the Sixteenth DOE Nuclear Air Cleaning Conference were: waste treatment, including volume reduction and storage; system and component response to stress and accident conditions; Three Mile Island accident; iodine adsorption; treatment and storage of noble gas: treatment of offgases from chemical processing; aerosol; behavior; containment venting; laboratory and in-place filter-testing methods; and particulate filtration. Volume I of the Proceedings has 49 papers from the following sessions; HEPA filter test methods; noble gas separation; air cleaning system design; containment venting; iodine adsorption; reprocessing offgas cleaning; critical review; filtration; filter testing; and aerosols. Volume II contains 44 papers from the sessions on: nuclear waste treatment; critical review; noble gas treatment; carbon-14 and tritium; air cleaning system response to stress; nuclear standards and safety; round table; open end; and air cleaning technology at Three Mile Island. Abstracts are provided for all of these papers

  17. 16th DOE nuclear air cleaning conference: proceedings

    International Nuclear Information System (INIS)

    First, M.W.

    1981-02-01

    Major topics discussed during the Sixteenth DOE Nuclear Air Cleaning Conference were: waste treatment, including volume reduction and storage; system and component response to stress and accident conditions; Three Mile Island accident; iodine adsorption; treatment and storage of noble gas; treatment of offgases from chemical processing; aerosol behavior; containment venting; laboratory and in-place filter-testing methods; and particulate filtration. Volume I of the Proceedings has 49 papers from the following sessions: HEPA filter test methods; noble gas separation; air cleaning system design; containment venting; iodine adsorption; reprocessing offgas cleaning; critical review; filtration, filter testing, and aerosols. Volume II contains 44 papers from the sessions on: nuclear waste treatment; critical review; noble gas treatment; carbon-14 and tritium; air cleaning system response to stress; nuclear standards and safety; round table; open end; and air cleaning technology at Three Mile Island. Abstracts are provided for all of these papers

  18. Post-CMP cleaning for metallic contaminant removal by using a remote plasma and UV/ozone

    International Nuclear Information System (INIS)

    Lim, Jong Min; Jeon, Bu Yong; Lee, Chong Mu

    2000-01-01

    For the chemical mechanical polishing (CMP) process to be successful, it is important to establish a good post-CMP cleaning process that will remove not only slurry and particles but also metallic impurities from the polished surface. The common metallic contaminants found after oxide CMP and Cu CMP include Cu, K, and Fe. Scrubbing, a popular method for post-CMP cleaning, is effective in removing particles, but removal of metallic contaminants using this method is not so effective. In this study, the removal of Fe metallic contaminants like Fe, which are commonly found on the wafer surface after CMP processes, was investigated using remote-hydrogen-plasma and UV/O 3 cleaning techniques. Our results show that metal contaminants, including Fe, can be effectively removed by using a hydrogen-plasma or UV/O 3 cleaning technique performed under optimal process conditions. In remote plasma H 2 cleaning, contaminant removal is enhanced with decreasing plasma exposure time and increasing rf-power. The optimal process condition for the removal of the Fe impurities existing on the wafer surface is an rf-power of 100 W. Plasma cleaning for 5 min or less is effective in removing Fe contaminants, but a plasma exposure time of 1 min is more appropriate than 5 min in view of the process time, The surface roughness decreased by 30∼50 % after remote-H 2 -plasma cleaning. On the other hand, the highest efficiency of Fe-impurity removal was achieved for an UV exposure time of 30 s. The removal mechanism for the Fe contaminants in the remote-H 2 -plasma and the UV/O 3 cleaning processes is considered to be the liftoff of Fe atoms when the SiO is removed by evaporation after the chemical or native SiO 2 formed underneath the metal atoms reacts with H + and e - to form SiO

  19. Electro-membrane processes for flue gas cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, T. F.

    1997-12-31

    Various techniques for NO removal in Membrane Contactor were considered. However the NO absorption in a liquid adsorbent with chemical enhancement and its ease for regeneration, was selected as the most practicable choice. Various different compounds for chemical enhancement were studied and Fe(II)-chelate enhanced adsorbent was selected for further studies. The technical feasibility of Fe(II)-chelate enhanced adsorbent for obtaining greater than 80% NO removal have been successfully established. Even though the membrane area required for greater than 80% NO removal has been found to be about 500 m{sup 2}/MW{sub c} (compared to 50 - 150 m{sup 2}/MW{sub c}, for 95% SO{sub 2} removal, depending on the membrane characteristics), suitable Membrane Contactor design has been proposed for carrying out the process at an acceptable gas side pressure drop. The electro-membrane processes for the regeneration of adsorbents have been studied both theoretically and experimentally. The theoretical studies have concerned the study of basic functions of both the bipolar membranes and charge laden (anion/cation) membranes. Suitable experimental techniques have been devised for studying of these basic parameters (e.g. charge transport number, salt diffusion through membranes, current-voltage characteristics of bipolar membranes and electrical resistance of charge laden membranes). These parameters have further been utilized in the mechanistic model of combined membranes in an ED cell (electrodialysis). Based on these fundamental studies and analysis of process requirements, suitable configuration of ED cell has been developed and verified by experimental studies. The effect of both the stack design parameters (e.g. number of cells, membrane type and spacer design) and the operational parameters (e.g. temperature, electrolyte concentration, liquid velocity and current density) have been studied for optimization of energy consumption for regeneration of loaded adsorbents. As a result

  20. Ultrasonic and immersion cleaning: a comparison using aqueous and fluorocarbon solvents

    International Nuclear Information System (INIS)

    Bond, R.D.; Kearsey, A.

    1984-11-01

    Decontamination is a necessary process in reducing radiation levels in the working environment in the nuclear industry. Components from active areas which require decontamination for re-use or maintenance operations. In this report, a typical chemical cleaning process using liquid pumping, airagitation and physical movement for agitation is compared with ultrasonic cleaning, now an established cleaning process in many industries. The chosen traditional method is immersion in an agitated solution of warm SDG.3 solution; an established decontaminating reagent. The decontamination effect of this process is compared with the effect of cleaning in an ultrasonic bath containing the same reagent at the same concentration and temperature. Fluorocarbon reagents are of particular interest to the nuclear industry for they offer the ability to clean electrical components without damage, and can clean product contaminated material without the risk of criticality. Such reagents are based on 1,1,2-trichloro, 1,2,2-trifluoroethane and azeotropic mixtures. This reagent and one mixture with 6% methanol were tested under agitation and ultrasonic immersion at the same temperature. Parallel control experiments were conducted using demineralised water as the cleaning media in an agitated bath. SGG3 is a good reagent for general purpose cleaning (it can remove 99% of particulate contamination) using scrubbing, immersion or spraying techniques. There is little evidence to show that ultrasonic cleaning increases its effectiveness. For special purpose fluorocarbon solvents will give satisfactory results when used in an ultrasonic system. (author)

  1. TECHNOLOGY OF REVERSE-BLAST CORROSION CLEANING OF STEEL SHEETS PRIOR TO LASER CUTTING

    Directory of Open Access Journals (Sweden)

    A. N. Zguk

    2017-01-01

    Full Text Available Quality of surface cleaning against corrosion influences on efficiency in realization of a number of technological processes. While using bentonite clays in power fluid reverse-blast cleaning ensures formation of anticorrosion protective coating with light absorbing properties on the cleaned surface and prevents formation of the repeated corrosion. The paper presents results of the investigations pertaining to influence of reverse-blast cleaning parameters of steel sheets on quality of the cleaned surface prior to laser cutting. Processing conditions, applied compositions of power fluid and also properties of the protective film coatings on the cleaned surface have been given in the paper. The paper considers topography, morphology and chemical composition of the given coating while applying complex metal micrographic, X-ray diffraction and electronic and microscopic investigations. A complex of laser cutting (refer to gas lasers with output continuous capacity of 2.5/4.0 kW has been applied for experimental works to evaluate influence of the formed surface quality on efficiency of laser cutting process. Specimens having dimension 120×120 mm, made of steel Ст3пс, with thickness from 3 to 10 mm have been prepared for the experiments. An analysis has shown that the application of reverse-blast cleaning ensures higher speed in laser cutting by a mean of 10–20 %. The investigations have made it possible to determine optimum cleaning modes: distance from a nozzle to the surface to be cleaned, jet velocity, pressure. It has been revealed that after drying of the specimens processed by power fluid based on water with concentrations of bentonite clay and calcined soda a protective film coating with thickness of some 5–7 µm has been formed on the whole cleaned specimen surfaces. Chemical base of the coating has been formed by the elements which are included in the composition of bentonite clay being the basic component of the power fluid. 

  2. Efficient methods of nanoimprint stamp cleaning based on imprint self-cleaning effect

    Energy Technology Data Exchange (ETDEWEB)

    Meng Fantao; Chu Jinkui [Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, 116024 Dalian (China); Luo Gang; Zhou Ye; Carlberg, Patrick; Heidari, Babak [Obducat AB, SE-20125 Malmoe (Sweden); Maximov, Ivan; Montelius, Lars; Xu, H Q [Division of Solid State Physics, Lund University, Box 118, S-22100 Lund (Sweden); Nilsson, Lars, E-mail: ivan.maximov@ftf.lth.se [Department of Food Technology, Engineering and Nutrition, Lund University, Box 117, S-22100 Lund (Sweden)

    2011-05-06

    Nanoimprint lithography (NIL) is a nonconventional lithographic technique that promises low-cost, high-throughput patterning of structures with sub-10 nm resolution. Contamination of nanoimprint stamps is one of the key obstacles to industrialize the NIL technology. Here, we report two efficient approaches for removal of typical contamination of particles and residual resist from stamps: thermal and ultraviolet (UV) imprinting cleaning-both based on the self-cleaning effect of imprinting process. The contaminated stamps were imprinted onto polymer substrates and after demolding, they were treated with an organic solvent. The images of the stamp before and after the cleaning processes show that the two cleaning approaches can effectively remove contamination from stamps without destroying the stamp structures. The contact angles of the stamp before and after the cleaning processes indicate that the cleaning methods do not significantly degrade the anti-sticking layer. The cleaning processes reported in this work could also be used for substrate cleaning.

  3. Application of rapid read-out cleaning indicators for improved process control in hospital sterile services departments.

    Science.gov (United States)

    Nugent, P G; Modi, T; McLeod, N; Bock, L J; Smith, C; Poolman, T M; Warburton, R; Meighan, P; Wells, P; Sutton, J M

    2013-05-01

    Heightened awareness of the importance of cleaning has led to an emphasis on automated systems for the decontamination of re-usable medical devices. The authors have previously described an enzymatic indicator system, based on thermostable adenylate kinases (tAK), for quantitative monitoring of automated cleaning processes within hospital sterile services departments (SSDs). To evaluate tAK indicators for routine process monitoring across a range of SSDs with different cleaning chemistries and different automated washer disinfectors (AWDs). tAK indicator devices and alternative industry test indicators were included in five independent cleaning cycles in each of eight different AWDs. Residual tAK post wash was determined by a coupled luciferase assay using a modified hygiene monitoring system. In all cases, with the exception of a single test, the alternative indicators showed that cleaning had been adequate. They were not able to discriminate between the performance of different processes. In contrast, the tAK indicators were able to resolve differences in the performance of processes across the different SSDs. Where the tAK indicators identified cleaning to the limits of detection of the assay, this demonstrated a log10 enzyme removal factor of >5.69. The results suggest that tAK indicators are suitable for providing improved process control for automated cleaning processes, being able to distinguish between wash performance in different hospital settings and between individual process runs. This technology is believed to be a useful addition to routine AWD performance qualification when used as a daily or weekly test. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  4. Characterization of Carbon-Contaminated B4C-Coated Optics after Chemically Selective Cleaning with Low-Pressure RF Plasma.

    Science.gov (United States)

    Moreno Fernández, H; Rogler, D; Sauthier, G; Thomasset, M; Dietsch, R; Carlino, V; Pellegrin, E

    2018-01-22

    Boron carbide (B 4 C) is one of the few materials that is expected to be most resilient with respect to the extremely high brilliance of the photon beam generated by free electron lasers (FELs) and is thus of considerable interest for optical applications in this field. However, as in the case of many other optics operated at light source facilities, B 4 C-coated optics are subject to ubiquitous carbon contaminations. Carbon contaminations represent a serious issue for the operation of FEL beamlines due to severe reduction of photon flux, beam coherence, creation of destructive interference, and scattering losses. A variety of B 4 C cleaning technologies were developed at different laboratories with varying success. We present a study regarding the low-pressure RF plasma cleaning of carbon contaminated B 4 C test samples via inductively coupled O 2 /Ar, H 2 /Ar, and pure O 2 RF plasma produced following previous studies using the same ibss GV10x downstream plasma source. Results regarding the chemistry, morphology as well as other aspects of the B 4 C optical coating before and after the plasma cleaning are reported. We conclude that among the above plasma processes only plasma based on pure O 2 feedstock gas exhibits the required chemical selectivity for maintaining the integrity of the B 4 C optical coatings.

  5. Cleaning Schedule Operations in Heat Exchanger Networks

    Directory of Open Access Journals (Sweden)

    Huda Hairul

    2018-01-01

    Full Text Available Heat exchanger networks have been known to be the essential parts in the chemical industries. Unfortunately, since the performance of heat exchanger can be decreasing in transferring the heat from hot stream into cold stream due to fouling, then cleaning the heat exchanger is needed to restore its initial performance periodically. A process of heating crude oil in a refinery plant was used as a case study. As many as eleven heat exchangers were used to heat crude oil before it was heated by a furnace to the temperature required to the crude unit distillation column. The purpose of this study is to determine the cleaning schedule of heat exchanger on the heat exchanger networks due to the decrease of the overall heat transfer coefficient by various percentage of the design value. A close study on the process of heat exchanger cleaning schedule in heat exchanger networks using the method of decreasing overall heat transfer coefficient as target. The result showed that the higher the fouling value the more often the heat exchanger is cleaned because the overall heat transfer coefficient decreases quickly.

  6. Prioritizing substitution of organic solvents in industrial cleaning processes

    DEFF Research Database (Denmark)

    Rasmussen, Pia Brunn; Jacobsen, Thomas

    1997-01-01

    A method for prioritizing the substitution of volatile organic compounds (VOC) used in industrial cleaning processes is developed. The result is a matrix, which, if all information can be obtained, gives a comprehensive description of the effects, exposure and emission of VOC, as well as the pros...

  7. Cleaning the soil

    International Nuclear Information System (INIS)

    Stegmann, R.

    1993-01-01

    Volume 6 of the Hamburg Reports contains contributions from scientists from the Special Research Field 188 'Cleaning up Contaminated Soils' of the Technical University of Hamburg-Harburg and the University of Hamburg and of experts from science and from the practical field. The soil science and analytical aspects of the biological and chemical/physical treatment processes are shown and open questions specific to processes are dealt with. Scientific results are compared with practical experience here. The evaluation of treated soils for reuse in the environment is a very important question, which is explained in the first articles here. Examples of case studies are shown in the last part of the volume. (orig.) [de

  8. Mechanical and chemical cleaning of the tubes bundles of the moisture separator reheaters (GSS) of Nuclear power plants

    International Nuclear Information System (INIS)

    Guerra, Patrice; Ruiz, Jose T.; Ureta, Roman; Carreres, Cristina; Virginie, Le-Guerroue

    2012-09-01

    The cleaning operation concerns the 'GSS' system (GSS stands for moisture separator reheaters, MSR) which are classified as 'watch quality guarantee', not classified as safety facility and subjected to Pressure Equipment regulations. The follow-up of the operational GSS (steel carbon) of EDF nuclear power plants CP0 group reveals a clog rate due to a relevant magnetite deposits that could result in equipment damage, loss of availability and loss of plant productivity. The pressure drop between inlet and outlet of the heating steam is close to maximum design criterion. The service consisted in designing, developing, qualifying and carrying out a process which removes clog from the inside of GSS U-tubes bundle located in the vapor circuit and which respects the equipment integrity and ensures the process harmlessness. This cleaning has to enable the complete removal of deposits and oxides (magnetite) in order to recover a passage diameter and a surface finish equivalent to the origin, thus avoiding the replacement of the GSS and obtaining a considerable reduction of costs. To do so, LAINSA and SOLARCA designed, developed, qualified and operated on 14 GSS bundles, by carrying out the following operations: - Cartography of the GSS tubes bundles clogging state; - Pre-Mechanical cleaning to un-block the sealed tubes and release the inside tubes passing; - Isolation of the bundle and check of leaks of the system; - Chemical cleaning with the efficiency and harmlessness parameters follow-up: - Acid Phase by means of weak organic acids to eliminate all the deposits; - Passivation phase; - Final Rinsing respecting the customer criteria; - Drying; - Waste management and waste treatment. The implementation of this operation enables the elimination of the whole deposits (magnetite) and oxides located inside the GSS tube bundle and thus to recover a passage diameter inside the tubes, and a pressure drop close to a new system and therefore to enables the

  9. Chemical hot gas purification for biomass gasification processes; Chemische Heissgasreinigung bei Biomassevergasungsprozessen

    Energy Technology Data Exchange (ETDEWEB)

    Stemmler, Michael

    2010-07-01

    The German government decided to increase the percentage of renewable energy up to 20 % of all energy consumed in 2020. The development of biomass gasification technology is advanced compared to most of the other technologies for producing renewable energy. So the overall efficiency of biomass gasification processes (IGCC) already increased to values above 50 %. Therefore, the production of renewable energy attaches great importance to the thermochemical biomass conversion. The feedstock for biomass gasification covers biomasses such as wood, straw and further energy plants. The detrimental trace elements released during gasification of these biomasses, e.g. KCl, H{sub 2}S and HCl, cause corrosion and harm downstream devices. Therefore, gas cleaning poses an especial challenge. In order to improve the overall efficiency this thesis aims at the development of gas cleaning concepts for the allothermic, water blown gasification at 800 C and 1 bar (Guessing-Process) as well as for the autothermic, water and oxygen blown gasification at 950 C and 18 bar (Vaernamo-Process). Although several mechanisms for KCl- and H{sub 2}S-sorption are already well known, the achievable reduction of the contamination concentration is still unknown. Therefore, calculations on the produced syngas and the chemical hot gas cleaning were done with a thermodynamic process model using SimuSage. The syngas production was included in the calculations because the knowledge of the biomass syngas composition is very limited. The results of these calculations prove the dependence of syngas composition on H{sub 2}/C-ratio and ROC (Relative Oxygen Content). Following the achievable sorption limits were detected via experiments. The KCl containing syngases were analysed by molecular beam mass spectrometry (MBMS). Furthermore, an optimised H{sub 2}S-sorbent was developed because the examined sorbents exceeded the sorption limit of 1 ppmv. The calculated sorption limits were compared to the limits

  10. Impact of operation conditions, foulant adsorption, and chemical cleaning on the nanomechanical properties of ultrafiltraion hollow fiber membranes

    KAUST Repository

    Gutierrez, Leonardo

    2018-04-06

    This study analyzed the change in nanomechanical properties of ultrafiltration hollow fiber membranes harvested from pilot-scale units after twelve months of operation. Quantitative Nanomechanical Mapping technique was used to distinguish between adhesion, dissipation, deformation, and modulus while simultaneously generating a topographic image of membranes. Nanomechanical maps of virgin membranes evidenced surfaces of heterogeneous properties and were described by probability density functions. Operating conditions and feed quality exerted an impact on membranes. Clean harvested membranes showed a higher mean modulus and dissipation, and a lower deformation than virgin membranes, indicating stiffer membranes of lower elastic deformation. A significant fraction of these measurements displayed peak values deviating from the distribution; which represents regions of the membrane with properties highly differing from the probability density function. The membrane polymeric material experienced severe physicochemical changes by foulant adsorption and reaction with cleaning agents. Foulant adsorption on membranes was heterogeneous in both morphology and mechanical properties and could not be statistically described. Foulants, i.e., mainly consisting of polysaccharides and proteinaceous structures, displayed low elastic deformation and high roughness and adhesion. The presence of foulants after chemical cleaning and their high adhesion would be a direct nanoscale evidence of irreversible fouling. By the end of the operation, the Trans-Membrane Pressure experienced a 40% increase. The cleaning process was not able to fully recover the initial TMP, indicating irreversible fouling, i.e., permanent change in membrane characteristics and decrease in performance. These results suggest a link between the macroscopic properties and nanomechanical characteristics of membranes. This study advances our nanoscale understanding of the impact of fouling and operating conditions on

  11. Steam generator cleaning campaigns at Bruce A: 1993-1996

    International Nuclear Information System (INIS)

    Puzzuoli, F.V.; Leinonen, P.J.; Lowe, G.A.

    1997-01-01

    Boiler chemical cleaning (BOCC) and high-pressure water lancing operations were performed during the Bruce A 1993 Unit 3, 1994 Unit 3, 1995 Unit 1 and 1996 Unit 3 outages to remove secondary side deposits. High-pressure water lancing focused on three boiler areas: tube support plates, to remove broached hole deposits, hot leg U-bend supports to dislodge deposits contributing to boiler tube stress corrosion cracking and tube sheets with the aim of removing accumulated sludge piles and post BOCC insoluble residues. The chemical cleaning processes applied were modified versions of the one developed by the Electric Power Research Institute/Steam Generator Owners Group. During these BOCC operations, corrosion for several key boiler materials was monitored and was well below the specified allowances

  12. Cleaning of Sodium in the Cold Trap

    International Nuclear Information System (INIS)

    Kim, Byung Ho; Jeong, Ji Young; Kim, Jong Man; Choi, Byung Hae; Nam, Ho Yun

    2005-01-01

    The purpose of a cleaning process is to remove the residual sodium adhering to the component walls once it has been properly drained. It is necessary to clean and decontaminate a component, especially the large components of the primary coolant system; such as the intermediate heat exchangers and the primary pump. Improper and inadequate cleaning has in a number of cases resulted in problems in the storage, handling, and reuse of components. Several types of failures due to improper cleaning procedures have been defined in the past. Inadequate and incomplete removal of sodium results in residues which may contain metallic sodium and alkaline compounds such as sodium hydroxide, sodium oxide, sodium carbonate, and various types of alcoholates. Reinsertion of components containing these compounds into a high-temperature sodium system can result in either the intergranular penetration characteristic of a high- oxygen sodium or an accelerated corrosion due to oxygen. The methods used for cleaning sodium equipment depend on the condition and types of equipment to be cleaned and whether the equipment is to be reused. Cleaning methods are needed that will avoid a deleterious local overheating, material surface degradation or deposits, chemical, physical, or mechanical damage, and external effects. This paper discusses a steam-nitrogen gas cleaning method for the routine applications that permits the reuse of the cold trap in sodium

  13. Method of manipulating the chemical properties of water to improve the effectiveness of a desired chemical process

    Science.gov (United States)

    Hawthorne, Steven B.; Miller, David J.; Yang, Yu; Lagadec, Arnaud Jean-Marie

    1999-01-01

    The method of the present invention is adapted to manipulate the chemical properties of water in order to improve the effectiveness of a desired chemical process. The method involves heating the water in the vessel to subcritical temperatures between 100.degree. to 374.degree. C. while maintaining sufficient pressure to the water to maintain the water in the liquid state. Various physiochemical properties of the water can be manipulated including polarity, solute solubility, surface tension, viscosity, and the disassociation constant. The method of the present invention has various uses including extracting organics from solids and semisolids such as soil, selectively extracting desired organics from nonaqueous liquids, selectively separating organics using sorbent phases, enhancing reactions by controlling the disassociation constant of water, cleaning waste water, and removing organics from water using activated carbon or other suitable sorbents.

  14. McClean Lake. Site Guide

    International Nuclear Information System (INIS)

    2016-09-01

    Located over 700 kilometers northeast of Saskatoon, Areva's McClean Lake site is comprised of several uranium mines and one of the most technologically advanced uranium mills in the world - the only mill designed to process high-grade uranium ore without dilution. Areva has operated several open-pit uranium mines at the McClean Lake site, and is evaluating future mines at and near the site. The McClean Lake mill has recently undergone a multimillion-dollar upgrade and expansion, which has doubled its annual production capacity of uranium concentrate to 24 million pounds. It is the only facility in the world capable of processing high-grade uranium ore without diluting it. The mill processes the ore from the Cigar Lake mine, the world's second largest and highest-grade uranium mine. The McClean Lake site operates 365 days a year on a week-in/week-out rotation schedule for workers, over 50% of whom reside in northern Saskatchewan communities. Tailings are waste products resulting from milling uranium ore. This waste is made up of leach residue solids, waste solutions and chemical precipitates that are carefully engineered for long-term disposal. The TMF serves as the repository for all resulting tailings. This facility allows proper waste management, which minimizes potential adverse environmental effects. Mining projections indicate that the McClean Lake mill will produce tailings in excess of the existing capacity of the TMF. After evaluating a number of options, Areva has decided to pursue an expansion of this facility. Areva is developing the Surface Access Borehole Resource Extraction (SABRE) mining method, which uses a high-pressure water jet placed at the bottom of the drill hole to extract ore. Areva has conducted a series of tests with this method and is evaluating its potential for future mining operations. McClean Lake maintains its certification in ISO 14001 standards for environmental management and OHSAS 18001 standards for occupational health

  15. New catalysts for clean environment

    Energy Technology Data Exchange (ETDEWEB)

    Maijanen, A; Hase, A [eds.; VTT Chemical Technology, Espoo (Finland)

    1997-12-31

    VTT launched a Research Programme on Chemical Reaction Mechanisms (CREAM) in 1993. The three-year programme (1993-1995) has focused on reaction mechanisms relevant to process industries and aimed at developing novel catalysts and biocatalysts for forest, food, and specialty chemicals industries as well as for energy production. The preliminary results of this programme have already been presented in the first symposium organized in Espoo in September 1994. To conclude the programme the second symposium is organized in Otaniemi, Espoo on January 29 - 30, 1996. Papers by 19 speakers and 17 poster presentations of the 1996 Symposium are included in this book. The Symposium consists of four sessions: Biotechnology for Natural Fibers Processing, New Biocatalysts, Catalysts for Clean Energy, and New Opportunities for Chemical Industry. The CREAM programme has tried to foresee solutions for the problems challenged by the public concern on environmental aspects, especially dealing with industrial processes and novel use of raw materials and energy. The programme has followed the basic routes that can lead to natural and simple solutions to develop processes in the fields of forest, food fine chemicals, and energy industry. This symposium presents the results of the programme to learn and further discuss together with the international experts that have been invited as keynote speakers. (author)

  16. New catalysts for clean environment

    Energy Technology Data Exchange (ETDEWEB)

    Maijanen, A.; Hase, A. [eds.] [VTT Chemical Technology, Espoo (Finland)

    1996-12-31

    VTT launched a Research Programme on Chemical Reaction Mechanisms (CREAM) in 1993. The three-year programme (1993-1995) has focused on reaction mechanisms relevant to process industries and aimed at developing novel catalysts and biocatalysts for forest, food, and specialty chemicals industries as well as for energy production. The preliminary results of this programme have already been presented in the first symposium organized in Espoo in September 1994. To conclude the programme the second symposium is organized in Otaniemi, Espoo on January 29 - 30, 1996. Papers by 19 speakers and 17 poster presentations of the 1996 Symposium are included in this book. The Symposium consists of four sessions: Biotechnology for Natural Fibers Processing, New Biocatalysts, Catalysts for Clean Energy, and New Opportunities for Chemical Industry. The CREAM programme has tried to foresee solutions for the problems challenged by the public concern on environmental aspects, especially dealing with industrial processes and novel use of raw materials and energy. The programme has followed the basic routes that can lead to natural and simple solutions to develop processes in the fields of forest, food fine chemicals, and energy industry. This symposium presents the results of the programme to learn and further discuss together with the international experts that have been invited as keynote speakers. (author)

  17. The role of surface chemical analysis in a study to select replacement processes for TCA vapor degreasing

    Science.gov (United States)

    Lesley, Michael W.; Davis, Lawrence E.; Moulder, John F.; Carlson, Brad A.

    1995-01-01

    The role of surface-sensitive chemical analysis (ESCA, AES, and SIMS) in a study to select a process to replace 1, 1, 1-trichloroethane (TCA) vapor degreasing as a steel and aluminum bonding surface preparation method is described. The effort was primarily concerned with spray-in-air cleaning processes involving aqueous alkaline and semi-aqueous cleaners and a contamination sensitive epoxy-to-metal bondline. While all five cleaners tested produced bonding strength results equal to or better than those produced by vapor degreasing, the aqueous alkaline cleaners yielded results which were superior to those produced by the semi-aqueous cleaners. The main reason for the enhanced performance appears to be a silicate layer left behind by the aqueous alkaline cleaners. The silicate layer increases the polarity of the surface and enhances epoxy-to-metal bonding. On the other hand, one of the semi-aqueous cleaners left a nonpolar carbonaceous residue which appeared to have a negative effect on epoxy-to-metal bonding. Differences in cleaning efficiency between cleaners/processes were also identified. These differences in surface chemistry, which were sufficient to affect bonding, were not detected by conventional chemical analysis techniques.

  18. Application of surface-enhanced Raman spectroscopy (SERS) for cleaning verification in pharmaceutical manufacture.

    Science.gov (United States)

    Corrigan, Damion K; Cauchi, Michael; Piletsky, Sergey; Mccrossen, Sean

    2009-01-01

    Cleaning verification is the process by which pharmaceutical manufacturing equipment is determined as sufficiently clean to allow manufacture to continue. Surface-enhanced Raman spectroscopy (SERS) is a very sensitive spectroscopic technique capable of detection at levels appropriate for cleaning verification. In this paper, commercially available Klarite SERS substrates were employed in order to obtain the necessary enhancement of signal for the identification of chemical species at concentrations of 1 to 10 ng/cm2, which are relevant to cleaning verification. The SERS approach was combined with principal component analysis in the identification of drug compounds recovered from a contaminated steel surface.

  19. Dry cleaning of fluorocarbon residues by low-power electron cyclotron resonance hydrogen plasma

    CERN Document Server

    Lim, S H; Yuh, H K; Yoon Eui Joon; Lee, S I

    1988-01-01

    A low-power ( 50 W) electron cyclotron resonance hydrogen plasma cleaning process was demonstrated for the removal of fluorocarbon residue layers formed by reactive ion etching of silicon dioxide. The absence of residue layers was confirmed by in-situ reflection high energy electron diffraction and cross-sectional high resolution transmission electron microscopy. The ECR hydrogen plasma cleaning was applied to contact cleaning of a contact string structure, resulting in comparable contact resistance arising during by a conventional contact cleaning procedure. Ion-assisted chemical reaction involving reactive atomic hydrogen species generated in the plasma is attributed for the removal of fluorocarbon residue layers.

  20. Petroleum storage tank cleaning using commercial microbial culture products

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, D.R.; Entzeroth, L.C.; Timmis, A.; Whiteside, A.; Hoskins, B.C.

    1995-12-31

    The removal of paraffinic bottom accumulations from refinery storage tanks represents an increasingly costly area of petroleum storage management. Microorganisms can be used to reduce paraffinic bottoms by increasing the solubility of bottom material and by increasing the wax-carrying capacity of carrier oil used in the cleaning process. The economic savings of such treatments are considerable. The process is also intrinsically safer than alternative methods, as it reduces and even eliminates the need for personnel to enter the tank during the cleaning process. Both laboratory and field sample analyses can be used to document changes in tank material during the treatment process. These changes include increases in volatile content and changes in wax distribution. Several case histories illustrating these physical and chemical changes are presented along with the economics of treatment.

  1. Facile Dry Surface Cleaning of Graphene by UV Treatment

    Science.gov (United States)

    Kim, Jin Hong; Haidari, Mohd Musaib; Choi, Jin Sik; Kim, Hakseong; Yu, Young-Jun; Park, Jonghyurk

    2018-05-01

    Graphene has been considered an ideal material for application in transparent lightweight wearable electronics due to its extraordinary mechanical, optical, and electrical properties originating from its ordered hexagonal carbon atomic lattice in a layer. Precise surface control is critical in maximizing its performance in electronic applications. Graphene grown by chemical vapor deposition is widely used but it produces polymeric residue following wet/chemical transfer process, which strongly affects its intrinsic electrical properties and limits the doping efficiency by adsorption. Here, we introduce a facile dry-cleaning method based on UV irradiation to eliminate the organic residues even after device fabrication. Through surface topography, Raman analysis, and electrical transport measurement characteristics, we confirm that the optimized UV treatment can recover the clean graphene surface and improve graphene-FET performance more effectively than thermal treatment. We propose our UV irradiation method as a systematically controllable and damage-free post process for application in large-area devices.

  2. Technical support for the Ohio Clean Coal Technology Program. Volume 2, Baseline of knowledge concerning process modification opportunities, research needs, by-product market potential, and regulatory requirements: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Olfenbuttel, R.; Clark, S.; Helper, E.; Hinchee, R.; Kuntz, C.; Means, J.; Oxley, J.; Paisley, M.; Rogers, C.; Sheppard, W.; Smolak, L. [Battelle, Columbus, OH (United States)

    1989-08-28

    This report was prepared for the Ohio Coal Development Office (OCDO) under Grant Agreement No. CDO/R-88-LR1 and comprises two volumes. Volume 1 presents data on the chemical, physical, and leaching characteristics of by-products from a wide variety of clean coal combustion processes. Volume 2 consists of a discussion of (a) process modification waste minimization opportunities and stabilization considerations; (b) research and development needs and issues relating to clean coal combustion technologies and by-products; (c) the market potential for reusing or recycling by-product materials; and (d) regulatory considerations relating to by-product disposal or reuse.

  3. Controlling the cost of clean air - A new clean coal technology

    International Nuclear Information System (INIS)

    Kindig, J.K.; Godfrey, R.L.

    1991-01-01

    This article presents the authors' alternative to expensive coal combustion products clean-up by cleaning the coal, removing the sulfur, before combustion. Topics discussed include sulfur in coal and the coal cleaning process, the nature of a new coal cleaning technology, the impact on Clean Air Act compliance, and the economics of the new technology

  4. Automated cleaning of electronic components

    International Nuclear Information System (INIS)

    Drotning, W.; Meirans, L.; Wapman, W.; Hwang, Y.; Koenig, L.; Petterson, B.

    1994-01-01

    Environmental and operator safety concerns are leading to the elimination of trichloroethylene and chlorofluorocarbon solvents in cleaning processes that remove rosin flux, organic and inorganic contamination, and particulates from electronic components. Present processes depend heavily on these solvents for manual spray cleaning of small components and subassemblies. Use of alternative solvent systems can lead to longer processing times and reduced quality. Automated spray cleaning can improve the quality of the cleaning process, thus enabling the productive use of environmentally conscious materials, while minimizing personnel exposure to hazardous materials. We describe the development of a prototype robotic system for cleaning electronic components in a spray cleaning workcell. An important feature of the prototype system is the capability to generate the robot paths and motions automatically from the CAD models of the part to be cleaned, and to embed cleaning process knowledge into the automatically programmed operations

  5. Importance of deposit information in the design and execution of steam generator chemical cleaning

    International Nuclear Information System (INIS)

    Flores, O.; Remark, J.

    1997-01-01

    During the planning stages of the chemical cleaning of the San Onofre Nuclear Generating Station (SONGS) units 2 and 3 steam generators, it was determined that an understanding of the steam generator deposit loading and composition was essential to the design and success of the project. It was also determined that qualification testing, preferably with actual deposits from the SONGS steam generators, was also essential. SONGS units 2 and 3 have Combustion Engineering (CE)-designed pressurized water reactors. Each unit has two CE model 3410 steam generators. Each steam generator has 9350 alloy 600 tubes with 1.9-cm (3/4 in.) outside diameter. Unit 2 began commercial operation in 1983, and unit 3, in 1984. The purpose of this technical paper is to explain the effort and methodology for deposit composition, characterization, and quantification. In addition, the deposit qualification testing and design of the cleaning are discussed

  6. Plasma cleaning for waste minimization

    Energy Technology Data Exchange (ETDEWEB)

    Ward, P.P.

    1993-07-01

    Although plasma cleaning is a recognized substitute for solvent cleaning in removing organic contaminants, some universal problems in plasma cleaning processes prevent wider use of plasma techniques. Lack of understanding of the fundamental mechanisms of the process, unreliable endpoint detection techniques, and slow process times make plasma cleaning processes less than desirable. Our approach to address these plasma cleaning problems is described. A comparison of plasma cleaning rates of oxygen and oxygen/sulfur hexafluoride gases shows that fluorine-containing plasmas can enhance etch rates by 400% over oxygen alone. A discussion of various endpoint indication techniques is discussed and compared for application suitability. Work toward a plasma cleaning database is discussed. In addition to the global problems of plasma cleaning, an experiment where the specific mixed-waste problem of removal of machine oils from radioactive scrap metal is discussed.

  7. Late washing filter cleaning cycle demonstration

    International Nuclear Information System (INIS)

    Meyer, M.L.; McCabe, D.J.

    1992-01-01

    The DWPF Late Washing Facility will filter cesium and potassium tetraphenyl borate (TPB) solids using a Mott sintered metal filter, identical to the filter now used in the In-tank Precipitation Facility. The purpose of the late wash step is primarily to remove the nitrite salts from the slurry prior to delivery to DWPF. Periodic chemical cleaning of the filter will be required, presumably after each batch although the actual required frequency could not be determined on the lab-scale. Minimization of chemical cleaning solution volumes is key to maximizing the attainment of the Late Wash facility. This report summarizes work completed in experiments designed to identify minimum cleaning solution requirements

  8. Keeping condensers clean

    Energy Technology Data Exchange (ETDEWEB)

    Wicker, K.

    2006-04-15

    The humble condenser is among the biggest contributors to a steam power plant's efficiency. But although a clean condenser can provide great economic benefit, a dirty one can raise plant heat rate, resulting in large losses of generation revenue and/or unnecessarily high fuel bills. Conventional methods for cleaning fouled tubes range form chemicals to scrapers to brushes and hydro-blasters. This article compares the available options and describes how one power station, Omaha Public Power District's 600 MW North Omaha coal-fired power station, cleaned up its act. The makeup and cooling water of all its five units comes from the Missouri River. 6 figs.

  9. Ecological effectiveness of oil spill countermeasures: how clean is clean?

    International Nuclear Information System (INIS)

    Baker, J.M.

    1999-01-01

    This paper with 94 references examines background levels of hydrocarbons and the difficulty of defining clean. Processes and timescales for natural cleaning, and factors affecting natural cleaning timescales are considered. Ecological advantages and disadvantages of clean-up methods are highlighted, and five case histories of oil spills are summarised. The relationships between ecological and socio-economic considerations, and the need for a net environmental benefit analysis which takes into account the advantages and disadvantages of clean-up responses and natural clean-up are discussed. A decision tree for evaluating the requirement for shore clean-up is illustrated. (UK)

  10. Cleaning, disinfection and sterilization of surface prion contamination.

    Science.gov (United States)

    McDonnell, G; Dehen, C; Perrin, A; Thomas, V; Igel-Egalon, A; Burke, P A; Deslys, J P; Comoy, E

    2013-12-01

    Prion contamination is a risk during device reprocessing, being difficult to remove and inactivate. Little is known of the combined effects of cleaning, disinfection and sterilization during a typical reprocessing cycle in clinical practice. To investigate the combination of cleaning, disinfection and/or sterilization on reducing the risk of surface prion contamination. In vivo test methods were used to study the impact of cleaning alone and cleaning combined with thermal disinfection and high- or low-temperature sterilization processes. A standardized test method, based on contamination of stainless steel wires with high titres of scrapie-infected brain homogenates, was used to determine infectivity reduction. Traditional chemical methods of surface decontamination against prions were confirmed to be effective, but extended steam sterilization was more variable. Steam sterilization alone reduced the risk of prion contamination under normal or extended exposure conditions, but did show significant variation. Thermal disinfection had no impact in these studies. Cleaning with certain defined formulations in combination with steam sterilization can be an effective prion decontamination process, in particular with alkaline formulations. Low-temperature, gaseous hydrogen peroxide sterilization was also confirmed to reduce infectivity in the presence and absence of cleaning. Prion decontamination is affected by the full reprocessing cycle used on contaminated surfaces. The correct use of defined cleaning, disinfection and sterilization methods as tested in this report in the scrapie infectivity assay can provide a standard precaution against prion contamination. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  11. A novel surface cleaning method for chemical removal of fouling lead layer from chromium surfaces

    International Nuclear Information System (INIS)

    Gholivand, Kh.; Khosravi, M.; Hosseini, S.G.; Fathollahi, M.

    2010-01-01

    Most products especially metallic surfaces require cleaning treatment to remove surface contaminations that remain after processing or usage. Lead fouling is a general problem which arises from lead fouling on the chromium surfaces of bores and other interior parts of systems which have interaction with metallic lead in high temperatures and pressures. In this study, a novel chemical solution was introduced as a cleaner reagent for removing metallic lead pollution, as a fouling metal, from chromium surfaces. The cleaner aqueous solution contains hydrogen peroxide (H 2 O 2 ) as oxidizing agent of lead layer on the chromium surface and acetic acid (CH 3 COOH) as chelating agent of lead ions. The effect of some experimental parameters such as acetic acid concentration, hydrogen peroxide concentration and temperature of the cleaner solution during the operation on the efficiency of lead cleaning procedure was investigated. The results of scanning electron microscopy (SEM) showed that using this procedure, the lead pollution layer could be completely removed from real chromium surfaces without corrosion of the original surface. Finally, the optimum conditions for the complete and fast removing of lead pollution layer from chromium surfaces were proposed. The experimental results showed that at the optimum condition (acetic acid concentration 28% (V/V), hydrogen peroxide 8% (V/V) and temperature 35 deg. C), only 15-min time is needed for complete removal of 3 g fouling lead from a chromium surface.

  12. Chemical process hazards analysis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    The Office of Worker Health and Safety (EH-5) under the Assistant Secretary for the Environment, Safety and Health of the US Department (DOE) has published two handbooks for use by DOE contractors managing facilities and processes covered by the Occupational Safety and Health Administration (OSHA) Rule for Process Safety Management of Highly Hazardous Chemicals (29 CFR 1910.119), herein referred to as the PSM Rule. The PSM Rule contains an integrated set of chemical process safety management elements designed to prevent chemical releases that can lead to catastrophic fires, explosions, or toxic exposures. The purpose of the two handbooks, ``Process Safety Management for Highly Hazardous Chemicals`` and ``Chemical Process Hazards Analysis,`` is to facilitate implementation of the provisions of the PSM Rule within the DOE. The purpose of this handbook ``Chemical Process Hazards Analysis,`` is to facilitate, within the DOE, the performance of chemical process hazards analyses (PrHAs) as required under the PSM Rule. It provides basic information for the performance of PrHAs, and should not be considered a complete resource on PrHA methods. Likewise, to determine if a facility is covered by the PSM rule, the reader should refer to the handbook, ``Process Safety Management for Highly Hazardous Chemicals`` (DOE- HDBK-1101-96). Promulgation of the PSM Rule has heightened the awareness of chemical safety management issues within the DOE. This handbook is intended for use by DOE facilities and processes covered by the PSM rule to facilitate contractor implementation of the PrHA element of the PSM Rule. However, contractors whose facilities and processes not covered by the PSM Rule may also use this handbook as a basis for conducting process hazards analyses as part of their good management practices. This handbook explains the minimum requirements for PrHAs outlined in the PSM Rule. Nowhere have requirements been added beyond what is specifically required by the rule.

  13. Proceedings of the 21st DOE/NRC Nuclear Air Cleaning Conference; Sessions 1--8

    Energy Technology Data Exchange (ETDEWEB)

    First, M.W. [ed.] [Harvard Univ., Boston, MA (United States). Harvard Air Cleaning Lab.

    1991-02-01

    Separate abstracts have been prepared for the papers presented at the meeting on nuclear facility air cleaning technology in the following specific areas of interest: air cleaning technologies for the management and disposal of radioactive wastes; Canadian waste management program; radiological health effects models for nuclear power plant accident consequence analysis; filter testing; US standard codes on nuclear air and gas treatment; European community nuclear codes and standards; chemical processing off-gas cleaning; incineration and vitrification; adsorbents; nuclear codes and standards; mathematical modeling techniques; filter technology; safety; containment system venting; and nuclear air cleaning programs around the world. (MB)

  14. Chemical pneumonitis

    Science.gov (United States)

    ... cleaning materials such as chlorine bleach, during industrial accidents, or near swimming pools) Grain and fertilizer dust ... and the A.D.A.M. Editorial team. Chemical Emergencies ... about A.D.A.M.'s editorial policy , editorial process and privacy policy . A.D.A.M. is ...

  15. 太阳能硅料化学清洗研究进展%Development of chemical cleaning for solar energy silicon material

    Institute of Scientific and Technical Information of China (English)

    申燕; 贾艳飞; 姚旭; 张健; 廉佳林

    2016-01-01

    Silicon as the main material of solar photovoltaic power generation in the solar photovoltaic industry, the demand for silicon material cleanliness also gradualy increases under the background of the rapid development of the market. Chemical cleaning is the main method of silicon material cleaning. In this paper, the research progress of the standard cleaning method ( RCA ) and depending on the silicon material by RCA method to develop other chemical cleaning method was reviewed.%多晶硅作为太阳能光伏发电的主要材料,在太阳能光伏产业市场迅速发展的大背景下,对硅料清洁度的需求也逐步增加。化学清洗是目前硅料清洗的主要方法。本文综述了近年来硅料化学清洗的基本方法(RCA)及根据硅料的不同由RCA法发展出的其他化学清洗方法。

  16. Effects of physical and chemical aspects on membrane fouling and cleaning using interfacial free energy analysis in forward osmosis.

    Science.gov (United States)

    Zhang, Wanzhu; Dong, Bingzhi

    2018-05-20

    Natural organic matter (NOM) in micro-polluted water purification using membranes is a critical issue to handle. Understanding the fouling mechanism in the forward osmosis (FO) process, particularly identifying the predominant factor that controls membrane fouling, could have significant effects on exerting the advantages of FO technique. Cellulose triacetate no-woven (CTA-NW) membrane is applied to experiments with a high removal efficiency (> 99%) for the model foulant. Tannic acid (TA) is used as a surrogate foulant for NOM in the membrane fouling process, thus enabling the analysis of the effects of physical and chemical aspects of water flux, retention, and adsorption. The membrane fouling behavior is affected mainly by the combined effects of the osmotic dragging force and the interaction of the pH in the working solution, foulants, and calcium ions, as demonstrated by the water flux loss and the changes of membrane retention and adsorption. The fouled CTA-NW membrane (in PRO mode) could be flux-recovered by > 85% through physical cleaning methods. The interfacial free energy analysis theory was used to analyze the membrane fouling behavior with calculating the interfacial cohesion and adhesion free energies. The cohesion free energy refers to the deposition of foulants (TA or TA combined with calcium ions) on a fouled membrane. In addition, the adhesion free energy could be used to evaluate the interaction between foulants and a clean membrane.

  17. How to Address the Data Quality Issues in Regression Models: A Guided Process for Data Cleaning

    Directory of Open Access Journals (Sweden)

    David Camilo Corrales

    2018-04-01

    Full Text Available Today, data availability has gone from scarce to superabundant. Technologies like IoT, trends in social media and the capabilities of smart-phones are producing and digitizing lots of data that was previously unavailable. This massive increase of data creates opportunities to gain new business models, but also demands new techniques and methods of data quality in knowledge discovery, especially when the data comes from different sources (e.g., sensors, social networks, cameras, etc.. The data quality process of the data set proposes conclusions about the information they contain. This is increasingly done with the aid of data cleaning approaches. Therefore, guaranteeing a high data quality is considered as the primary goal of the data scientist. In this paper, we propose a process for data cleaning in regression models (DC-RM. The proposed data cleaning process is evaluated through a real datasets coming from the UCI Repository of Machine Learning Databases. With the aim of assessing the data cleaning process, the dataset that is cleaned by DC-RM was used to train the same regression models proposed by the authors of UCI datasets. The results achieved by the trained models with the dataset produced by DC-RM are better than or equal to that presented by the datasets’ authors.

  18. Flux recovery of ceramic tubular membranes fouled with whey proteins: Some aspects of membrane cleaning

    Directory of Open Access Journals (Sweden)

    Popović Svetlana S.

    2008-01-01

    Full Text Available Efficiency of membrane processes is greatly affected by the flux reduction due to the deposits formation at the surface and/or in the pores of the membrane. Efficiency of membrane processes is affected by cleaning procedure applied to regenerate flux. In this work, flux recovery of ceramic tubular membranes with 50 and 200 nm pore size was investigated. The membranes were fouled with reconstituted whey solution for 1 hour. After that, the membranes were rinsed with clean water and then cleaned with sodium hydroxide solutions or formulated detergents (combination of P3 Ultrasil 67 and P3 Ultrasil 69. Flux recovery after the rinsing step was not satisfactory although fouling resistance reduction was significant so that chemical cleaning was necessary. In the case of 50 nm membrane total flux recovery was achieved after cleaning with 1.0% (w/w sodium hydroxide solution. In the case of 200 nm membrane total flux recovery was not achieved irrespective of the cleaning agent choice and concentration. Cleaning with commercial detergent was less efficient than cleaning with the sodium hydroxide solution.

  19. Ultrasound in chemical processes

    International Nuclear Information System (INIS)

    Baig, S.; Farooq, R.; Malik, A.H.

    2009-01-01

    The use of ultrasound to promote chemical reactions or sono chemistry is a field of chemistry which involves the process of acoustic cavitations i.e. the collapse of microscopic bubbles in liquid. There are two essential components for the application of sono chemistry, a liquid medium and a source of high-energy vibrations. The liquid medium is necessary because sono chemistry is driven by acoustic cavitations that can only occur in liquids. The source of the vibrational energy is the transducer. The chemical effects of ultrasound include the enhancement of reaction rates at ambient temperatures and striking advancements in stoichiometric and catalytic reactions In some cases, ultrasonic irradiation can increase reactivities by nearly million fold. The ultrasound has large number of applications not only in emending old chemical processes but also in developing new synthetic strategies. Ultrasound enhances all chemical and physical processes e.g., crystallization, vitamin synthesis, preparation of catalysts, dissolution of chemicals, organometallic reactions, electrochemical processes, etc. High-power ultrasonics is a new powerful technology that is not only safe and environmentally friendly in its application but is also efficient and economical. It can be applied to existing processes to eliminate the need for chemicals and/or heat application in a variety of industrial processes. (author)

  20. Cleaning conveyor belts in the chicken-cutting area of a poultry processing plant with 45°c water.

    Science.gov (United States)

    Soares, V M; Pereira, J G; Zanette, C M; Nero, L A; Pinto, J P A N; Barcellos, V C; Bersot, L S

    2014-03-01

    Conveyor belts are widely used in food handling areas, especially in poultry processing plants. Because they are in direct contact with food and it is a requirement of the Brazilian health authority, conveyor belts are required to be continuously cleaned with hot water under pressure. The use of water in this procedure has been questioned based on the hypothesis that water may further disseminate microorganisms but not effectively reduce the organic material on the surface. Moreover, reducing the use of water in processing may contribute to a reduction in costs and emission of effluents. However, no consistent evidence in support of removing water during conveyor belt cleaning has been reported. Therefore, the objective of the present study was to compare the bacterial counts on conveyor belts that were or were not continuously cleaned with hot water under pressure. Superficial samples from conveyor belts (cleaned or not cleaned) were collected at three different times during operation (T1, after the preoperational cleaning [5 a.m.]; T2, after the first work shift [4 p.m.]; and T3, after the second work shift [1:30 a.m.]) in a poultry meat processing facility, and the samples were subjected to mesophilic and enterobacterial counts. For Enterobacteriaceae, no significant differences were observed between the conveyor belts, independent of the time of sampling or the cleaning process. No significant differences were observed between the counts of mesophilic bacteria at the distinct times of sampling on the conveyor belt that had not been subjected to continuous cleaning with water at 45°C. When comparing similar periods of sampling, no significant differences were observed between the mesophilic counts obtained from the conveyor belts that were or were not subjected to continuous cleaning with water at 45°C. Continuous cleaning with water did not significantly reduce microorganism counts, suggesting the possibility of discarding this procedure in chicken processing.

  1. Commercial Cleaning Products for Chemical Decontamination: A Scoping Study

    Science.gov (United States)

    2014-05-01

    and may injure human skin without dilution), although this approach is less favoured in a mass casualty decontamination situation than soap and water...commercial cleaning products, full strength K-O-K® liquid bleach (5.25% aqueous solution of NaOCl), dish-washing detergent Cascade® with Extra...Bleach Action Gel, OxiClean® Versatile Stain Remover Powder, and ZEP® Industrial Purple liquid cleaner (proprietary caustic cleaner containing

  2. Clean slate corrective action investigation plan

    International Nuclear Information System (INIS)

    1996-05-01

    The Clean Slate sites discussed in this report are situated in the central portion of the Tonopah Test Range (TTR), north of the Nevada Test Site (NTS) on the northwest portion of the Nellis Air Force Range (NAFR) which is approximately 390 kilometers (km) (240 miles [mi]) northwest of Las Vegas, Nevada. These sites were the locations for three of the four Operation Roller Coaster experiments. These experiments evaluated the dispersal of plutonium in the environment from the chemical explosion of a plutonium-bearing device. Although it was not a nuclear explosion, Operation Roller Coaster created some surface contamination which is now the subject of a corrective action strategy being implemented by the Nevada Environmental Restoration Project (NV ERP) for the U.S. Department of Energy (DOE). Corrective Action Investigation (CAI) activities will be conducted at three of the Operation Roller Coaster sites. These are Clean Slate 1 (CS-1), Clean Slate 2 (CS-2), and Clean Slate 3 (CS-3) sites, which are located on the TTR. The document that provides or references all of the specific information relative to the various investigative processes is called the Corrective Action Investigation Plan (CAIP). This CAIP has been prepared for the DOE Nevada Operations Office (DOE/NV) by IT Corporation (IT)

  3. Clean slate corrective action investigation plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    The Clean Slate sites discussed in this report are situated in the central portion of the Tonopah Test Range (TTR), north of the Nevada Test Site (NTS) on the northwest portion of the Nellis Air Force Range (NAFR) which is approximately 390 kilometers (km) (240 miles [mi]) northwest of Las Vegas, Nevada. These sites were the locations for three of the four Operation Roller Coaster experiments. These experiments evaluated the dispersal of plutonium in the environment from the chemical explosion of a plutonium-bearing device. Although it was not a nuclear explosion, Operation Roller Coaster created some surface contamination which is now the subject of a corrective action strategy being implemented by the Nevada Environmental Restoration Project (NV ERP) for the U.S. Department of Energy (DOE). Corrective Action Investigation (CAI) activities will be conducted at three of the Operation Roller Coaster sites. These are Clean Slate 1 (CS-1), Clean Slate 2 (CS-2), and Clean Slate 3 (CS-3) sites, which are located on the TTR. The document that provides or references all of the specific information relative to the various investigative processes is called the Corrective Action Investigation Plan (CAIP). This CAIP has been prepared for the DOE Nevada Operations Office (DOE/NV) by IT Corporation (IT).

  4. (Preoxidation cleaning optimization for crystalline silicon)

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    A series of controlled experiments has been performed in Sandia's Photovoltaic Device Fabrication Laboratory to evaluate the effect of various chemical surface treatments on the recombination lifetime of crystalline silicon wafers subjected to a high-temperature dry oxidation. From this series of experiments we have deduced a relatively simple yet effective cleaning sequence. We have also evaluated the effect of different chemical damage-removal etches for improving the recombination lifetime and surface smoothness of mechanically lapped wafers. This paper presents the methodology used, the experimental results obtained, and our experience with using this process on a continuing basis over a period of many months. 7 refs., 4 figs., 1 tab.

  5. A new cleaning process for the metallic contaminants on a post-CMP wafer's surface

    International Nuclear Information System (INIS)

    Gao Baohong; Liu Yuling; Wang Chenwei; Wang Shengli; Zhou Qiang; Tan Baimei; Zhu Yadong

    2010-01-01

    This paper presents a new cleaning process using boron-doped diamond (BDD) film anode electrochemical oxidation for metallic contaminants on polished silicon wafer surfaces. The BDD film anode electrochemical oxidation can efficiently prepare pyrophosphate peroxide, pyrophosphate peroxide can oxidize organic contaminants, and pyrophosphate peroxide is deoxidized into pyrophosphate. Pyrophosphate, a good complexing agent, can form a metal complex, which is a structure consisting of a copper ion, bonded to a surrounding array of two pyrophosphate anions. Three polished wafers were immersed in the 0.01 mol/L CuSO 4 solution for 2 h in order to make comparative experiments. The first one was cleaned by pyrophosphate peroxide, the second by RCA (Radio Corporation of America) cleaning, and the third by deionized (DI) water. The XPS measurement result shows that the metallic contaminants on wafers cleaned by the RCA method and by pyrophosphate peroxide is less than the XPS detection limits of 1 ppm. And the wafer's surface cleaned by pyrophosphate peroxide is more efficient in removing organic carbon residues than RCA cleaning. Therefore, BDD film anode electrochemical oxidation can be used for microelectronics cleaning, and it can effectively remove organic contaminants and metallic contaminants in one step. It also achieves energy saving and environmental protection. (semiconductor technology)

  6. Discussion on cleaning and maintenance of YA system reverse osmosis membrane

    International Nuclear Information System (INIS)

    Zhu Yidong

    2012-01-01

    According to the overproof of pollution data of YA system reverse osmosis membrane in extension project, the daily maintenance company is using chemical cleaning on reverse osmosis unit to eliminate the pollution blindly, the fixed prescription, fixed dosage and high frequency of the chemical cleaning. The writer analyzed the cause of the membrane pollution and commended several chemical cleaning methods by the long-period study of the system, and also some suggestion, according to the status of operational site, for the daily maintenance. (author)

  7. Flue Gas Cleaning With Alternative Processes and Reaction Media

    DEFF Research Database (Denmark)

    Rasmussen, Søren Birk; Huang, Jun; Riisager, Anders

    2007-01-01

    Alternative methods to the traditional industrial NOX and SOXflue gas cleaning processes working at lower temperatures and/orleading to useful products are desired. In this work we presentour latest results regarding the use of molten ionic media inelectrocatalytic membrane separation, ionic liquid...... reversibleabsorption and supported ionic liquid deNOX catalysis. Furtherdevelopment of the methods will hopefully make them suitable forinstallation in different positions in the flue gas duct ascompared to the industrial methods available today....

  8. Surface cleaning and preparation in AlGaN/GaN-based HEMT processing as assessed by X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Gonzalez-Posada, Fernando; Bardwell, Jennifer A.; Moisa, Simona; Haffouz, Soufien; Tang, Haipeng; Brana, Alejandro F.; Munoz, Elias

    2007-01-01

    The chemical composition of the AlGaN/GaN surface during typical process steps in transistor fabrication was studied using X-ray photoelectron spectroscopy (XPS). The steps studied included organic solvent cleaning, 1:1 HCl:H 2 O dip, buffered oxide etch dip, oxygen plasma descum and rapid thermal annealing (RTA). The surface composition was calculated after correction for the interference of the Ga Auger lines in the N 1s portion of the spectra. The buffered oxide etched (BOE) surface showed a greater tendency for Al (compared to Ga) to be oxidized in the surface, under a layer of adventitious carbon. Three different treatments were found to yield a combination of low C and O levels in the surface. Both plasma cleaning and RTA were highly effective at reducing the carbon contamination of the surface, but did increase the oxygen levels. The RTA treated surface was found to have low levels of oxygen incorporation to a depth of 2-6 nm

  9. Identifying optimal cleaning cycles for heat exchangers subject to fouling and ageing

    International Nuclear Information System (INIS)

    Pogiatzis, Thomas; Ishiyama, Edward M.; Paterson, William R.; Vassiliadis, Vassilios S.; Wilson, D. Ian

    2012-01-01

    Fouling of heat exchangers causes reduced heat transfer and other penalties. Regular cleaning represents one widely used fouling mitigation strategy, where the schedule of cleaning actions can be optimised to minimise the cost of fouling. This paper investigates, for the first time, the situation where there are two cleaning methods available so that the mode of cleaning has to be selected as well as the cleaning interval. Ageing is assumed to convert the initial deposit, labelled 'gel', into a harder and more conductive form, labelled 'coke', which cannot be removed by one of the cleaning methods. The second method can remove both the gel layer and the coke layer, but costs more and requires the unit to be off-line longer for cleaning. Experimental data demonstrating the effects of ageing are presented. The industrial application is the comparison of cleaning-in-place methods with off-line mechanical cleaning. A process model is constructed for an isolated counter-current heat exchanger subject to fouling, where ageing is described by a simple two-layer model. Solutions generated by an NLP-based approach prove to be superior to a simpler heuristic. A series of case studies demonstrate that combinations of chemical and mechanical cleaning can be superior to mechanical cleaning alone for certain combinations of parameters.

  10. Design of off-gas and air cleaning systems at nuclear power plants

    International Nuclear Information System (INIS)

    1987-01-01

    The primary purpose of this report is to describe the current design of air and process off-gas cleaning technologies used in nuclear power plants (NPPs). Because of the large inventory of fission products that are produced in the fuel (i.e. in the range of 5x10 19 Bq per GW(e)·a) and the highly restrictive airborne radionuclide release limits being established by Member States, air and process off-gas cleaning technologies are constantly being improved to provide higher airborne radionuclide recovery efficiencies and a smaller probability of malfunction. For various technologies considered an attempt has been made to provide the following information: (a) Process description in terms of principles of off-gas and air cleaning, operating parameters and system performance; (b) Design for normal and accident situations; (c) Design of components with regard to construction materials, size, shape and geometry of the system, resistance to chemical and physical degradation from the operational environment, safety and quality assurance requirements

  11. Permeability recovery of fouled forward osmosis membranes by chemical cleaning during a long-term operation of anaerobic osmotic membrane bioreactors treating low-strength wastewater.

    Science.gov (United States)

    Wang, Xinhua; Hu, Taozhan; Wang, Zhiwei; Li, Xiufen; Ren, Yueping

    2017-10-15

    Anaerobic osmotic membrane bioreactor (AnOMBR) has gained increasing interests in wastewater treatment owing to its simultaneous recovery of biogas and water. However, the forward osmosis (FO) membrane fouling was severe during a long-term operation of AnOMBRs. Here, we aim to recover the permeability of fouled FO membranes by chemical cleaning. Specifically speaking, an optimal chemical cleaning procedure was searched for fouled thin film composite polyamide FO (TFC-FO) membranes in a novel microfiltration (MF) assisted AnOMBR (AnMF-OMBR). The results indicated that citric acid, disodium ethylenediaminetetraacetate (EDTA-2Na), hydrochloric acid (HCl), sodium dodecyl sulfate (SDS) and sodium hydroxide (NaOH) had a low cleaning efficiency of less than 15%, while hydrogen peroxide (H 2 O 2 ) could effectively remove foulants from the TFC-FO membrane surface (almost 100%) through oxidizing the functional group of the organic foulants and disintegrating the colloids and microbe flocs into fine particles. Nevertheless, the damage of H 2 O 2 to the TFC-FO membrane was observed when a high cleaning concentration and a long duration were applied. In this case, the optimal cleaning conditions including cleaning concentration and time for fouled TFC-FO membranes were selected through confocal laser scanning microscope (CLSM) and scanning electron microscopy (SEM) images and the flux recovery rate. The results suggested that the optimal cleaning procedure for fouled TFC-FO membranes was use of 0.5% H 2 O 2 at 25 °C for 6 h, and after that, the cleaned TFC-FO membrane had the same performance as a virgin one including water flux and rejection for organic matters and phosphorus during the operation of AnMF-OMBR. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Process/Equipment Co-Simulation on Syngas Chemical Looping Process

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Liang; Zhou, Qiang; Fan, Liang-Shih

    2012-09-30

    The chemical looping strategy for fossil energy applications promises to achieve an efficient energy conversion system for electricity, liquid fuels, hydrogen and/or chemicals generation, while economically separate CO{sub 2} by looping reaction design in the process. Chemical looping particle performance, looping reactor engineering, and process design and applications are the key drivers to the success of chemical looping process development. In order to better understand and further scale up the chemical looping process, issues such as cost, time, measurement, safety, and other uncertainties need to be examined. To address these uncertainties, advanced reaction/reactor modeling and process simulation are highly desired and the modeling efforts can accelerate the chemical looping technology development, reduce the pilot-scale facility design time and operating campaigns, as well as reduce the cost and technical risks. The purpose of this work is thus to conduct multiscale modeling and simulations on the key aspects of chemical looping technology, including particle reaction kinetics, reactor design and operation, and process synthesis and optimization.

  13. A new multiple-stage electrocoagulation process on anaerobic digestion effluent to simultaneously reclaim water and clean up biogas.

    Science.gov (United States)

    Liu, Zhiguo; Stromberg, David; Liu, Xuming; Liao, Wei; Liu, Yan

    2015-03-21

    A new multiple-stage treatment process was developed via integrating electrocoagulation with biogas pumping to simultaneously reclaim anaerobic digestion effluent and clean up biogas. The 1st stage of electrocoagulation treatment under the preferred reaction condition led to removal efficiencies of 30%, 81%, 37% and >99.9% for total solids, chemical oxygen demand, total nitrogen and total phosphorus, respectively. Raw biogas was then used as a reactant and pumped into the effluent to simultaneously neutralize pH of the effluent and remove H2S in the biogas. The 2nd stage of electrocoagulation treatment on the neutralized effluent showed that under the selected reaction condition, additional 60% and 10% of turbidity and chemical oxygen demand were further removed. The study concluded a dual-purpose approach for the first time to synergistically combine biogas purification and water reclamation for anaerobic digestion system, which well addresses the downstream challenges of anaerobic digestion technology. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Basis for the life cycle assessment (LCA) of cleaning-in-place systems in milk processing plants; Bases para el analisis de ciclo de vida de los sistemas de limpieza in situ en plantas de la industria lactea

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barral, S.; Laca Perez, A.; Gutierrez Lavin, A.; Diaz Fernandez, M.; Rendueles de la Vega, M.; Iglesias Gonzalez, E.

    2006-07-01

    Milk processing requires high hygienic operations in order to assure safe products of high quality and suitable for human diet. The cleaning operations that take place during milk processing, do cause environmental impact, because of the high volume of wastewater generated, which is contaminated with rests of milk, detergents and other chemical products. The life cycle assessment of cleaning operations can be a powerful tool to evaluate the environmental impact associated with different operation methodologies. In this work, two current alternatives are studied, by means of operational data of a dairy plant. (Author) 7 refs.

  15. 40 CFR 262.213 - Laboratory clean-outs.

    Science.gov (United States)

    2010-07-01

    ... eligible academic entity is not required to count a hazardous waste that is an unused commercial chemical..., subpart C) generated solely during the laboratory clean-out toward its hazardous waste generator status... out, the date the laboratory clean-out begins and ends, and the volume of hazardous waste generated...

  16. [Cleaning and disinfection of surfaces in hospitals: Data on structure, process and result in the Frankfurt/Main Metropolitan Area].

    Science.gov (United States)

    Hausemann, A; Hofmann, H; Otto, U; Heudorf, Ursel

    2015-06-01

    In addition to hand hygiene and reprocessing of medical products, cleaning and disinfection of surfaces is also an important issue in the prevention of germ transmission and by implication infections. Therefore, in 2014, the quality of the structure, process and result of surface preparation of all hospitals in Frankfurt am Main, Germany, was monitored. All 17 hospitals transferred information on the quality of structure. Process quality was obtained through direct observation during cleaning and disinfection of rooms and their plumbing units. Result quality was gained using the fluorescent method, i.e. marking surfaces with a fluorescent liquid and testing if this mark has been sufficiently removed by cleaning. Structure quality: in all hospitals the employees were trained regularly. In 12 of them, the foremen had the required qualifications, in 6 hospitals unclarity as to the intersection of the cleaning and care services remained. In 14 hospitals only visible contamination was cleaned on the weekends, whereas complete cleaning was reported to take place in 12 hospitals on Saturdays and in 2 hospitals on Sundays. The contractually stipulated cleaning (observations specified in brackets) averaged 178 m(2)/h (148 m(2)/h) per patient room and 69 m(2)/h (33 m(2)/h) for bathrooms. Process quality: during process monitoring, various hand contact surfaces were prepared insufficiently. Result quality: 63 % of fluorescent markings were appropriately removed. The need for improvement is given especially in the area of the qualification of the foremen and a in a clear definition of the intersection between cleaning and care services, as well as in the regulations for weekends and public holidays.

  17. Automated cleaning and pre-processing of immunoglobulin gene sequences from high-throughput sequencing

    Directory of Open Access Journals (Sweden)

    Miri eMichaeli

    2012-12-01

    Full Text Available High throughput sequencing (HTS yields tens of thousands to millions of sequences that require a large amount of pre-processing work to clean various artifacts. Such cleaning cannot be performed manually. Existing programs are not suitable for immunoglobulin (Ig genes, which are variable and often highly mutated. This paper describes Ig-HTS-Cleaner (Ig High Throughput Sequencing Cleaner, a program containing a simple cleaning procedure that successfully deals with pre-processing of Ig sequences derived from HTS, and Ig-Indel-Identifier (Ig Insertion – Deletion Identifier, a program for identifying legitimate and artifact insertions and/or deletions (indels. Our programs were designed for analyzing Ig gene sequences obtained by 454 sequencing, but they are applicable to all types of sequences and sequencing platforms. Ig-HTS-Cleaner and Ig-Indel-Identifier have been implemented in Java and saved as executable JAR files, supported on Linux and MS Windows. No special requirements are needed in order to run the programs, except for correctly constructing the input files as explained in the text. The programs' performance has been tested and validated on real and simulated data sets.

  18. An efficient, environmentally acceptable, clean up system for well completions

    International Nuclear Information System (INIS)

    Berg, Oe.; Saasen, A.

    1996-01-01

    Evaluation of different casing cleaning fluid systems has been a difficult task due to the lack of a standardised laboratory measurement technique for technical performance. In order to meet the need for a reliable evaluation of different chemicals and fluid systems used in casing cleaning, a laboratory procedure for the evaluation of casing cleaning chemicals has been developed. This procedure has been successfully applied in the development of a new environmentally acceptable casing cleaning fluid system. Two different procedures are presented. An old method where the drilling fluid was displaced down the annulus and up the drill string was found to be ineffective compared to a method where the drilling fluid was displaced up in the annulus. The application of this procedure together with the use of the new chemical additive has reduced the cost of casing cleanup operations in the range of 30-40%. 10 refs., 1 fig., 4 tabs

  19. A novel compound cleaning solution for benzotriazole removal after copper CMP

    International Nuclear Information System (INIS)

    Gu Zhangbing; Liu Yuling; Gao Baohong; Wang Chenwei; Deng Haiwen

    2015-01-01

    After the chemical mechanical planarization (CMP) process, the copper surface is contaminated by a mass of particles (e.g. silica) and organic residues (e.g. benzotriazole), which could do great harm to the integrated circuit, so post-CMP cleaning is essential. In particular, benzotriazole (BTA) forms a layer of Cu-BTA film with copper on the surface, which leads to a hydrophobic surface of copper. So an effective cleaning solution is needed to remove BTA from the copper surface. In this work, a new compound cleaning solution is designed to solve two major problems caused by BTA: one is removing BTA and the other is copper surface corrosion that is caused by the cleaning solution. The cleaning solution is formed of alkaline chelating agent (FA/O II type), which is used to remove BTA, and a surfactant (FA/O I type), which is used as a corrosion inhibitor. BTA removal is characterized by contact angle measurements and electrochemical techniques. The inhibiting corrosion ability of the surfactant is also characterized by electrochemical techniques. The proposed compound cleaning solution shows advantages in removing BTA without corroding the copper surface. (paper)

  20. A Miniature Wastewater Cleaning Plant to Demonstrate Primary Treatment in the Classroom

    Science.gov (United States)

    Ne´el, Bastien; Cardoso, Catia; Perret, Didier; Bakker, Eric

    2015-01-01

    A small-scale wastewater cleaning plant is described that includes the key physical pretreatment steps followed by the chemical treatment of mud by flocculation. Water, clay particles, and riverside deposits mimicked odorless wastewater. After a demonstration of the optimization step, the flocculation process was carried out with iron(III)…

  1. Decreasing Beam Auto Tuning Interruption Events with In-Situ Chemical Cleaning on Axcelis GSD

    International Nuclear Information System (INIS)

    Fuchs, Dieter; Spreitzer, Stefan; Vogl, Josef; Bishop, Steve; Eldridge, David; Kaim, Robert

    2008-01-01

    Ion beam auto tuning time and success rate are often major factors in the utilization and productivity of ion implanters. Tuning software frequently fails to meet specified setup times or recipe parameters, causing production stoppages and requiring manual intervention. Build-up of conductive deposits in the arc chamber and extraction gap can be one of the main causes of auto tuning problems. The deposits cause glitching and ion beam instabilities, which lead to errors in the software optimization routines. Infineon Regensburg has been testing use of XeF 2 , an in-situ chemical cleaning reagent, with positive results in reducing auto tuning interruption events.

  2. Cleaning UF membranes with simple and formulated solutions

    NARCIS (Netherlands)

    Levitsky, I.; Duek, A.; Naim, R.; Arkhangelsky, E.; Gitis, V.

    2012-01-01

    The ultrafiltration membranes fouled by proteins are typically cleaned by consecutive soaking in alkali, surfactant and oxidizing solutions. We combined all three chemicals into a formulated cleaning agent and examined its efficiency to restore the water flux without damaging the membrane or

  3. Acid leaching of coal: to produce clean fuels from Turkish lignite

    Energy Technology Data Exchange (ETDEWEB)

    Seferinoglu, Meryem [Mineral Research and Exploration Directorate (Turkey)], email: meryem_seferinoglu66@yahoo.com; Duzenli, Derya [Ankara Central Laboratory (Turkey)

    2011-07-01

    With the increasing concerns about the environment, energy producers and governments are looking at developing clean energy sources. However, Turkey has limited clean energy resources and is using low grade coal which has high sulphur content as an alternative energy source. The aim of this paper is to study the possibility of generating clean fuel from Edirne Lignite and to get a better understanding of chemical mechanisms involved in coal leaching with hydrofluoric acid (HF) solutions. Leaching was conducted on Edirne Lignite with HF solution at ambient temperature and the effects of parameters such as reaction time and concentration of acid solutions on the process were evaluated. The optimum conditions were found and it was shown that ash levels can be reduced from 28.9% to 10.5% and the calorific value increased by 500kcal/kg with the HF leaching method. This study demonstrated that the production of clean fuel from high sulphur lignite is possible.

  4. Basis of the detection, assessment and cleaning up of sites contaminated with heavy metals

    International Nuclear Information System (INIS)

    Calmano, W.; Foerstner, U.

    1993-01-01

    The cleaning up of sites contaminated with heavy metals is still in its infancy. Depending on the type and extent of the contamination, new methods of treatment must be developed and matched to each situation. A survey is given of the groundwater contamination of soil heavy metals; the binding, availability and mobilisation of heavy metals; geo-chemical concepts for sites contaminated by heavy metals; judging the potential danger; safety measures; cleaning up processes and the reinstatement and renaturing of the soil. (orig.) [de

  5. Processing method of radioactive cleaning drain

    International Nuclear Information System (INIS)

    Otsuka, Shigemitsu; Murakami, Tadashi; Kitao, Hideo

    1998-01-01

    Upon processing of radioactive cleaning drains, contained Co-60 is removed by a selectively adsorbing adsorbent. In addition, after removing suspended materials by a filtering device, Co-60 as predominant nuclides in the drain is selectively adsorbed. The concentration of objective Co-60 is in the order of 0.1 Bq/cc, and non-radioactive metal ions such as Na + ions are present in the order of ppm in addition to Co-60. A granular adsorbent for selectively adsorbing Co-60 is oxine-added activated carbon, and has a grain size of from 20 to 48 mesh. The granular adsorbent is used while being filled in an adsorbing tower. Since a relatively simple device comprising the filtering device and the adsorbing tower in combination is provided, the reduction of the construction cost can be expected. In addition, since no filtering aid is used in the filtering device, the amount of secondary wastes is small. (N.H.)

  6. Investigation of the timesaver process for de-burring and cleaning the plate for the Atlas Tilecalorimeter

    International Nuclear Information System (INIS)

    Guarino, V.; Kocenko, L.; Wood, K.

    1997-01-01

    The Timesaver belt grinding machine has been selected by the Atlas collaboration for deburring the master and spacer plates after die stamping and laser cutting, respectively. However, the question has been raised as to whether or not the plates are sufficiently clean after going through the Timesaver machine to immediately be glued into a submodule assembly. This would greatly enhance the production of submodules because the task of cleaning individual master and spacer plates is labor intensive and time consuming as well as raises environmental issues with the detergent that is used. In order to investigate the possibility of using the Timesaver process to clean the plates as well as debur them, several plates were run through the machine and their cleanliness inspected before and after. In addition, several glue samples were subjected to the same process, glued, and then pulled apart in an attempt to gauge the cleanliness of the plates. From this series of tests it can be concluded that the wet Timesaver machine can adequately prepare the surface of the master and spacer plates as well as clean the plates for gluing. The machine was able to adequately remove all of the oil and grime from the test plates. Also, from the single test on the dry machine it appears that significant cleaning will be required to adequately clean the plates before gluing in order to remove the remaining grit

  7. Results of the secondary side chemical cleaning of the steam generators

    International Nuclear Information System (INIS)

    Doma, A.; Patek, G.

    2001-01-01

    A significant amount of deposit has developed on the secondary side of the heat transfer tubes of the steam generators (SG) of the Paks Nuclear Power Plant units in course of the years. More than 99.5% of the deposit is made up of magnetite (Fe 3 O 4 ) generated in the secondary circuit of the power plant. Those deposits lead to the decrease of the heat transfer. Even more important is its role from the point of view of operational reliability of the steam generators, leak tightness between the primary and secondary sides. The first series of cleaning took place following 8-9 years of operation of the units. Following the first cleaning cycle the transport of the corrosion products into the steam generators did not change, and thus obviously new cleaning was required. Periodical cleaning of the steam generators shall be assured. (R.P.)

  8. Laser cleaning of sulfide scale on compressor impeller blade

    International Nuclear Information System (INIS)

    Tang, Q.H.; Zhou, D.; Wang, Y.L.; Liu, G.F.

    2015-01-01

    Highlights: • The effects of sulfide layers and fluence values on the mechanism of laser cleaning were experimentally established. • The specimen surface with sulfide scale becomes slightly smoother than that before laser cleaning. • The mechanism of laser cleaning the sulfide scale of stainless steel is spallation without oxidization. • It would avoid chemical waste and dust pollution using a fiber laser instead of using nitric acids or sandblasting. - Abstract: Sulfide scale on the surface of a compressor impeller blade can considerably reduce the impeller performance and its service life. To prepare for subsequent remanufacturing, such as plasma spraying, it needs to be removed completely. In the corrosion process on an FV(520)B stainless steel, sulfide scale is divided into two layers because of different outward diffusion rates of Cr, Ni and Fe. In this paper, the cleaning threshold values of the upper and inner layers and the damage threshold value of the substrate were investigated using a pulsed fiber laser. To obtain experimental evidence, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and 3D surface profilometry were employed to investigate the two kinds of sulfide layers on specimens before, during, and after laser cleaning.

  9. Chemical mode control in nuclear power plant decommissioning during operation of technologies in individual radioactive waste processing plants

    International Nuclear Information System (INIS)

    Horvath, J.; Dugovic, L.

    1999-01-01

    Sewage treatment of nuclear power plant decommissioning is performed by system of sewage concentration in evaporator with formation of condensed rest, it means radioactive waste concentrate and breeding steam. During sewage treatment plant operation department of chemical mode performs chemical and radiochemical analysis of sewage set for treatment, chemical and radiochemical analysis of breeding steam condensate which is after final cleaning on ionization filter and fulfilling the limiting conditions released to environment; chemical and radiochemical analysis of heating steam condensate which is also after fulfilling the limiting conditions released to environment. Condensed radioactive concentrate is stored in stainless tanks and later converted into easy transportable and chemically stable matrix from the long term storage point of view in republic storage Mochovce. The article also refer to bituminous plant, vitrification plant, swimming pool decontamination plant of long term storage and operation of waste processing plant Bohunice

  10. Electrochemical cleaning of Sv-08G2S wire surface

    International Nuclear Information System (INIS)

    Kozlov, E.I.; Degtyarev, V.G.; Novikov, M.P.

    1981-01-01

    Results of industrial tests of the Sv-08G2S wire with different state of surface fwith technological lubrication, after mechanical cleaning, with electrochemically cleaned surface) are presented. Advantages of welding-technological properties of the wire with electroe chemically cleaned surface are shown. An operation principle of the electrochemical cleaning facility is described. A brief specf ification f of the facility is given [ru

  11. Solar photocatalytic cleaning of polluted water. Solare Reinigung verschmutzter Waesser mittels Photokatalyse

    Energy Technology Data Exchange (ETDEWEB)

    Bockelmann, D

    1994-01-01

    Alternatively to biological, physical and chemical methods of waste water cleaning, photocatalysis can be employed. In this residue-free method, titanium dioxide particles are brought into contact with polluted water as photocatalysts. Under UV irradiation at wave-lengths below 400 nm, change carriers are generated in the semiconductor particles that act so intensely oxidizing as to completely degrade almost all organic pollutants in waste water. In this process, the ultra-violet part of the solar spectrum can be harnessed to generate oxidation equivalents. Thus, solar photocatalytic waste water cleaning is excellently suited for developing countries. (BWI)

  12. Rapid formation of phase-clean 110 K (Bi-2223) powders derived via freeze-drying process

    Science.gov (United States)

    Balachandran, U.

    1996-06-04

    A process for the preparation of amorphous precursor powders for Pb-doped Bi{sub 2}Sr{sub 2} Ca{sub 2}Cu{sub 3}O{sub x} (2223) includes a freeze-drying process incorporating a splat-freezing step. The process generally includes splat freezing a nitrate solution of Bi, Pb, Sr, Ca, and Cu to form flakes of the solution without any phase separation; grinding the frozen flakes to form a powder; freeze-drying the frozen powder; heating the dried powder to form a dry green precursor powders; denitrating the green-powders; heating the denitrated powders to form phase-clean Bi-2223 powders. The grain boundaries of the 2223 grains appear to be clean, leading to good intergrain contact between 2223 grains. 11 figs.

  13. Cleaning graphene with a titanium sacrificial layer

    International Nuclear Information System (INIS)

    Joiner, C. A.; Roy, T.; Hesabi, Z. R.; Vogel, E. M.; Chakrabarti, B.

    2014-01-01

    Graphene is a promising material for future electronic applications and chemical vapor deposition of graphene on copper is a promising method for synthesizing graphene on the wafer scale. The processing of such graphene films into electronic devices introduces a variety of contaminants which can be difficult to remove. An approach to cleaning residues from the graphene channel is presented in which a thin layer of titanium is deposited via thermal e-beam evaporation and immediately removed. This procedure does not damage the graphene as evidenced by Raman spectroscopy, greatly enhances the electrical performance of the fabricated graphene field effect transistors, and completely removes the chemical residues from the surface of the graphene channel as evidenced by x-ray photoelectron spectroscopy.

  14. Cleaning products and air fresheners: exposure to primary and secondary air pollutants

    DEFF Research Database (Denmark)

    Nazaroff, W.; Weschler, Charles J.

    2004-01-01

    Building occupants, including cleaning personnel, are exposed to a wide variety of airborne chemicals when cleaning agents and air fresheners are used in buildings. Certain of these chemicals are listed by the state of California as toxic air contaminants (TACs) and a subset of these are regulated...... by the US federal government as hazardous air pollutants (HAPs). California's Proposition 65 list of species recognized as carcinogens or reproductive toxicants also includes constituents of certain cleaning products and air fresheners. In addition, many cleaning agents and air fresheners contain chemicals...... that can react with other air contaminants to yield potentially harmful secondary products. For example, terpenes can react rapidly with ozone in indoor air generating many secondary pollutants, including TACs such as formaldehyde. Furthermore, ozone-terpene reactions produce the hydroxyl radical, which...

  15. Chemical and mechanical decontamination processes to minimize secondary waste decommissioning

    International Nuclear Information System (INIS)

    Enda, M.; Ichikawa, N.; Yaita, Y.; Kanasaki, T.; Sakai, H.

    2008-01-01

    In the decommissioning of commercial nuclear reactors in Japan, prior to the dismantling of the nuclear power plants, there are plans to use chemical techniques to decontaminate reactor pressure vessels (RPVs), internal parts, primary loop recirculation systems (PLRs), reactor water clean up systems (RWCUs), etc., so as to minimize radiation sources in the materials to be disposed of. After dismantling the nuclear power plants, chemical and mechanical decontamination techniques will then be used to reduce the amounts of radioactive metallic waste. Toshiba Corporation has developed pre-dismantling and post-dismantling decontamination systems. In order to minimize the amounts of secondary waste, the T-OZON process was chosen for decontamination prior to the dismantling of nuclear power plants. Dismantling a nuclear power plant results in large amounts of metallic waste requiring decontamination; for example, about 20,000 tons of such waste is expected to result from the dismantling of a 110 MWe Boiling Water Reactor (BWR). Various decontamination methods have been used on metallic wastes in preparation for disposal in consideration of the complexity of the shapes of the parts and the type of material. The materials in such nuclear power plants are primarily stainless steel and carbon steel. For stainless steel parts having simple shapes, such as plates and pipes, major sources of radioactivity can be removed from the surface of the parts by bipolar electrolysis (electrolyte: H 2 SO 4 ). For stainless steel parts having complicated shapes, such as valves and pumps, major sources of radioactivity can be removed from the surfaces by redox chemical decontamination treatments (chemical agent: Ce(IV)). For carbon steel parts having simple shapes, decontamination by blasting with zirconia grit is effective in removing major sources of radioactivity at the surface, whereas for carbon steel parts having complicated shapes, major sources of radioactivity can be removed from

  16. Reactive chemicals and process hazards

    International Nuclear Information System (INIS)

    Surianarayanan, M.

    2016-01-01

    Exothermic chemical reactions are often accompanied by significant heat release, and therefore, need a thorough investigation before they are taken to a plant scale. Sudden thermal energy releases from exothermic decompositions and runaway reactions have contributed to serious fire and explosions in several chemical process plants. Similarly, thermal runaway had also occurred in storage and transportation of reactive chemicals. The secondary events of thermal runaway reactions can be rupture of process vessel, toxic spills and release of explosive vapor clouds or combination of these also. The explosion hazards are governed by the system thermodynamics and kinetics of the thermal process. Theoretical prediction of limiting temperature is difficult due to process complexities. Further, the kinetic data obtained through classical techniques, at conditions far away from runaway situation, is often not valid for assessing the runaway behavior of exothermic processes. The main focus of this lecture is to discuss the causes and several contributing factors for thermal runaway and instability and present analyses of the methodologies of the new instrumental techniques for assessing the thermal hazards of reactive chemicals during processing, storage and transportation. (author)

  17. Laser surface cleaning

    International Nuclear Information System (INIS)

    Freiwald, J.G.; Freiwald, D.A.

    1994-01-01

    The objective of this work is a laboratory demonstration that red-lead primer and two-part epoxy paints can be stripped from concrete and metal surfaces using surface cleaning systems based on pulsed-repetition CO 2 lasers. The three goals are to: (1) demonstrate coatings removal, including surface pore cleaning; (2) demonstrate that there is negligible release of ablated contaminants to the environment; and (3) demonstrate that the process will generate negligible amounts of additional waste compared to competing technologies. Phase 1 involved site visits to RMI and Fernald to assess the cleaning issues for buildings and parts. In addition, Phase 1 included detailed designs of a more powerful system for industrial cleaning rates, including laser, articulating optics, ablated-material capture suction nozzle attached to a horizontal raster scanner for floor cleaning, and filtration system. Some concept development is also being done for using robots, and for parts cleaning. In Phase 2 a transportable 6 kW system will be built and tested, with a horizontal surface scanner for cleaning paint from floors. The laboratory tests will again be instrumented. Some concept development will continue for using robots, and for parts cleaning. This report describes Phase 1 results

  18. Plasma-chemical processes and systems

    International Nuclear Information System (INIS)

    Castro B, J.

    1987-01-01

    The direct applications of plasma technology on chemistry and metallurgy are presented. The physical fundaments of chemically active non-equilibrium plasma, the reaction kinetics, and the physical chemical transformations occuring in the electrical discharges, which are applied in the industry, are analysed. Some plasma chemical systems and processes related to the energy of hydrogen, with the chemical technology and with the metallurgy are described. Emphasis is given to the optimization of the energy effectiveness of these processes to obtain reducers and artificial energetic carriers. (M.C.K.) [pt

  19. Private Exploration Primitives for Data Cleaning

    OpenAIRE

    Ge, Chang; Ilyas, Ihab F.; He, Xi; Machanavajjhala, Ashwin

    2017-01-01

    Data cleaning, or the process of detecting and repairing inaccurate or corrupt records in the data, is inherently human-driven. State of the art systems assume cleaning experts can access the data (or a sample of it) to tune the cleaning process. However, in many cases, privacy constraints disallow unfettered access to the data. To address this challenge, we observe and provide empirical evidence that data cleaning can be achieved without access to the sensitive data, but with access to a (no...

  20. Hazardous air pollutant emissions from process units in the synthetic organic chemical manufacturing industry: Background information for proposed standards. Volume 1A. National impacts assessment. Draft report

    International Nuclear Information System (INIS)

    1992-11-01

    A draft rule for the regulation of emissions of organic hazardous air pollutants (HAP's) from chemical processes of the synthetic organic chemical manufacturing industry (SOCMI) is being proposed under the authority of Sections 112, 114, 116, and 301 of the Clean Air Act, as amended in 1990. The volume of the Background Information Document presents the results of the national impacts assessment for the proposed rule

  1. Raman enhancement on ultra-clean graphene quantum dots produced by quasi-equilibrium plasma-enhanced chemical vapor deposition.

    Science.gov (United States)

    Liu, Donghua; Chen, Xiaosong; Hu, Yibin; Sun, Tai; Song, Zhibo; Zheng, Yujie; Cao, Yongbin; Cai, Zhi; Cao, Min; Peng, Lan; Huang, Yuli; Du, Lei; Yang, Wuli; Chen, Gang; Wei, Dapeng; Wee, Andrew Thye Shen; Wei, Dacheng

    2018-01-15

    Graphene is regarded as a potential surface-enhanced Raman spectroscopy (SERS) substrate. However, the application of graphene quantum dots (GQDs) has had limited success due to material quality. Here, we develop a quasi-equilibrium plasma-enhanced chemical vapor deposition method to produce high-quality ultra-clean GQDs with sizes down to 2 nm directly on SiO 2 /Si, which are used as SERS substrates. The enhancement factor, which depends on the GQD size, is higher than conventional graphene sheets with sensitivity down to 1 × 10 -9  mol L -1 rhodamine. This is attributed to the high-quality GQDs with atomically clean surfaces and large number of edges, as well as the enhanced charge transfer between molecules and GQDs with appropriate diameters due to the existence of Van Hove singularities in the electronic density of states. This work demonstrates a sensitive SERS substrate, and is valuable for applications of GQDs in graphene-based photonics and optoelectronics.

  2. Hazardous air pollutant emissions from process units in the synthetic organic chemical manufacturing industry: Background information for proposed standards. Volume 1B. Control technologies. Draft report

    International Nuclear Information System (INIS)

    1992-11-01

    A draft rule for the regulation of emissions of organic hazardous air pollutants (HAP's) from chemical processes of the synthetic organic chemical manufacturing industry (SOCMI) is being proposed under the authority of Sections 112, 114, 116, and 301 of the Clean Air Act, as amended in 1990. The volume of the Background Information Document presents discussions of control technologies used in the industry and the costs of those technologies

  3. Fundamentals and applications of dry CO2 cryogenic aerosol for photomask cleaning

    Science.gov (United States)

    Varghese, Ivin; Balooch, Mehdi; Bowers, Charles W.

    2010-09-01

    There is a dire need for the removal of all printable defects on lithography masks. As the technology node advances, smaller particles need to be efficiently removed from smaller features without any damage or adders. CO2 cryogenic aerosol cleaning is a dry, residue-free and chemically inert technique that doesn't suffer from disadvantages of conventional wet cleaning methods such as transmission/reflectivity loss, phase change, CD change, haze/progressive defects, and/or limitation on number of cleaning cycles. Ultra-pure liquid CO2 when dispensed through an optimally designed nozzle results in CO2 clusters that impart the required momentum for defect removal. Historically nanomachining debris removal has been established with this technique. Several improvements have been incorporated for cleaning of advanced node masks, which has enabled Full Mask Final Clean, a new capability that has been successfully demonstrated. The properties of the CO2 clusters can be captured utilizing the Phase Doppler Anemometry (PDA) and effect of varying process and design parameters can be verified. New nozzles have been designed to widen the cleaning process window for advanced node optical masks, without any damage to the weak primary features and/or sub-resolution assist features (SRAFs). This capability has been experimentally proven for high aspect ratio SRAFs e.g. 2.79 (52nm wide by 145 nm tall) as well as SRAFs 45nm wide by 73 nm tall. In this paper, 100% removal of soft defects that would have printed on advanced node masks is demonstrated. No printed defects larger than 50nm is observed after the CO2 cleaning. Stability of the cleaning and handling mechanisms has been demonstrated over the last 4.5 months in a production environment. The CO2 cleaning technique is expected to be effective for more advanced masks and Extreme Ultra-Violet (EUV) lithography.

  4. Canyon solvent cleaning

    International Nuclear Information System (INIS)

    Reif, D.J.

    1986-01-01

    The HM Process at the Savannah River Plant (SRP) uses 7.5% tributylphosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, produce decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown the carbonate washing, although removing residual solvent activity does not remove binding ligands that hold fission products in the solvent. Treatment of solvent by an alumina adsorption process removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale alumina adsorption process and the use of the process to clean HM Process first cycle solvent are presented

  5. Investigation of Alternative Approaches for Cleaning Mott Porous Metal Filters

    International Nuclear Information System (INIS)

    Poirier, M.R.

    2003-01-01

    The Department of Energy selected Caustic Side Solvent Extraction (CSSX) as the preferred cesium removal technology for Savannah River Site (SRS) waste. As a pretreatment step for the CSSX flowsheet, the incoming salt solution that contains entrained sludge is contacted with monosodium titanate (MST) to adsorb strontium and select actinides. The resulting slurry is filtered to remove the sludge and MST. Filter fouling occurs during this process. At times, personnel can increase the filtrate rate by backpulsing or scouring. At other times, the filtrate rate drops significantly and only chemical cleaning will restore filter performance. The current baseline technology for filter cleaning uses 0.5 M oxalic acid. The Salt Processing Project (SPP) at SRS, through the Tanks Focus Area, requested an evaluation of other cleaning agents to determine their effectiveness at removing trapped sludge and MST solids compared with the baseline oxalic acid method. A review of the technical literature identified compounds that appear effective at dissolving solid compounds. Consultation with the SPP management team, engineering personnel, and researchers led to a selection of oxalic acid, nitric acid, citric acid, and ascorbic acid for testing. Tests used simulated waste and actual waste as follows. Personnel placed simulated or actual SRS High Level Waste sludge and MST in a beaker. They added the selected cleaning agents, stirred the beakers, and collected supernate samples periodically analyzing for dissolved metals

  6. Fiscal 1995 research investigation on chemical process technology using supercritical fluid; 1995 nendo chorinkai ryutai wo riyoshita kagaku process gijutsu ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    With relation to the supercritical fluid utilization technology, conducted in fiscal 1995 were collection of basic data, extraction of R and D subjects and survey/analysis of application fields based on the literature survey and overseas field survey. From the research results, the following were selected as research subjects: as to the clean/recycling process technology, non-selection cascade treatment process of mixed waste plastics, hazardous waste treatment process, and radioactive waste treatment process. As to the unused resource utilization process technology, the supercritical submerged combustion power generation process, heavy hydrocarbon resource reutilization process, biomass synthetic utilization process, and carbon dioxide reutilization process. As to the next generation reaction process technology, the simple reaction process, de-organic solvent process, chemical materialization process for methane, and reaction separation combined process. As the innovative material process technology, the plastic forming process, high-functional materials, high-efficiency energy conversion materials, and heightening of function of solid wastes. 537 refs., 116 figs., 54 tabs.

  7. Efficient methods of piping cleaning

    Directory of Open Access Journals (Sweden)

    Orlov Vladimir Aleksandrovich

    2014-01-01

    Full Text Available The article contains the analysis of the efficient methods of piping cleaning of water supply and sanitation systems. Special attention is paid to the ice cleaning method, in course of which biological foil and various mineral and organic deposits are removed due to the ice crust buildup on the inner surface of water supply and drainage pipes. These impurities are responsible for the deterioration of the organoleptic properties of the transported drinking water or narrowing cross-section of drainage pipes. The co-authors emphasize that the use of ice compared to other methods of pipe cleaning has a number of advantages due to the relative simplicity and cheapness of the process, economical efficiency and lack of environmental risk. The equipment for performing ice cleaning is presented, its technological options, terms of cleansing operations, as well as the volumes of disposed pollution per unit length of the water supply and drainage pipelines. It is noted that ice cleaning requires careful planning in the process of cooking ice and in the process of its supply in the pipe. There are specific requirements to its quality. In particular, when you clean drinking water system the ice applied should be hygienically clean and meet sanitary requirements.In pilot projects, in particular, quantitative and qualitative analysis of sediments adsorbed by ice is conducted, as well as temperature and the duration of the process. The degree of pollution of the pipeline was estimated by the volume of the remote sediment on 1 km of pipeline. Cleaning pipelines using ice can be considered one of the methods of trenchless technologies, being a significant alternative to traditional methods of cleaning the pipes. The method can be applied in urban pipeline systems of drinking water supply for the diameters of 100—600 mm, and also to diversion collectors. In the world today 450 km of pipelines are subject to ice cleaning method.Ice cleaning method is simple

  8. Outsourcing Housekeeping: An insight into two cleaning companies, SOL and N-Clean, in Helsinki, Finland

    OpenAIRE

    Hussain, Samra

    2016-01-01

    The purpose of the author was to find to get an insight into the cleaning companies, in Helsin-ki, Finland, which the hotel industry is using as an external supplier for their housekeeping de-partment. The author has looked into the cleaning companies training process for the cleaning staff, employee demographics, quality control and process of handling complaints. The ad-vantages and disadvantages of outsourcing housekeeping in the hotel sector are also investi-gated. The research method...

  9. Cleaning Process Versus Laser-Damage Threshold of Coated Optical Components

    International Nuclear Information System (INIS)

    Rigatti, A.L.

    2005-01-01

    The cleaning of optical surfaces is important in the manufacture of high-laser-damage-threshold coatings, which are a key component on peak-power laser systems such as OMEGA located at the Laboratory for Laser Energetics (LLE). Since cleaning adds time, labor, and ultimately cost to the final coated component, this experiment was designed to determine the impact of different cleaning protocols on the measured laser-damage performance

  10. Modular Chemical Process Intensification: A Review.

    Science.gov (United States)

    Kim, Yong-Ha; Park, Lydia K; Yiacoumi, Sotira; Tsouris, Costas

    2017-06-07

    Modular chemical process intensification can dramatically improve energy and process efficiencies of chemical processes through enhanced mass and heat transfer, application of external force fields, enhanced driving forces, and combinations of different unit operations, such as reaction and separation, in single-process equipment. These dramatic improvements lead to several benefits such as compactness or small footprint, energy and cost savings, enhanced safety, less waste production, and higher product quality. Because of these benefits, process intensification can play a major role in industrial and manufacturing sectors, including chemical, pulp and paper, energy, critical materials, and water treatment, among others. This article provides an overview of process intensification, including definitions, principles, tools, and possible applications, with the objective to contribute to the future development and potential applications of modular chemical process intensification in industrial and manufacturing sectors. Drivers and barriers contributing to the advancement of process intensification technologies are discussed.

  11. EM-21 Alternative Enhanced Chemical Cleaning Program For Sludge Heel Removal

    International Nuclear Information System (INIS)

    Hay, M.; King, W.; Martino, C.

    2009-01-01

    Preliminary studies in the EM-21 Alternative Chemical Cleaning Program have focused on understanding the dissolution of Hematite (a primary sludge heel phase) in oxalic acid, with a focus on minimizing oxalic acid usage. Literature reviews, thermodynamic modeling, and experimental results have all confirmed that pH control, preferably using a supplemental proton source, is critical to oxalate minimization. With pH control, iron concentrations as high as 0.103 M have been obtained in 0.11 M oxalic acid. This is consistent with the formation of a 1:1 (iron:oxalate) complex. The solubility of Hematite in oxalic acid has been confirmed to increase by a factor of 3 when the final solution pH decreases from 5 to below 1. This is consistent with literature predictions of a shift in speciation from a 1:3 to 1:1 as the pH is lowered. Above a solution pH of 6, little Hematite dissolves. These results emphasize the importance of pH control in optimizing Hematite dissolution in oxalic acid.

  12. On-line chemical cleaning of pipelines; Limpieza quimica de ductos en linea

    Energy Technology Data Exchange (ETDEWEB)

    Cross, Michael Brent [Brenntag Stinnes Logistics, Muelheim/Ruhr (Germany)

    2003-07-01

    The concern of efficiency and maintenance in the pipeline industry, due to fluids and sediments, has led the development of new methods of cleaning. Some methods of cleaning are described in this work with their advantages and disadvantages.

  13. The Role of Chemical Processes in the Transition to Sustainable Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Stucki, S.; Palumbo, R.; Baltensperger, U.; Boulouchos, K.; Haas, O.; Scherer, G.G.; Siegwolf, R.; Wokaun, A

    2002-01-01

    Chemical science and engineering play a central role in improving the eco- efficiency of energy services, be it by optimizing fossil fuel utilization from the source to the sinks, be it by exploring new ways of replacing fossil fuels with renewable ones. Catalytic fuel processing is required for providing clean and easy to convert inputs from contaminated and/or high molecular weight primary resources into efficient energy conversion systems such as advanced combustion engines and fuel cells. The switch from conventional fossil fuel resources to renewables such as solar or biomass requires new approaches in chemical engineering. Efficiency vs. emissions trade-offs for improving the eco-performance of combustion engines need to be optimized with improved understanding of the complex chemistry taking place in flames. New materials for fuel cells and batteries provide a means of making these devices applicable, thereby drastically cutting down on emissions from energy systems. Chemistry is not only involved in fuel processing and conversion, but it is also important at the end of the pipe, i.e. in catalytic emission control devices, in the treatment of hazardous residues from the incineration of waste materials, and in the complex interactions of air pollutants with the biosphere. (author)

  14. Ensuring clean air: Developing a clean air strategy for British Columbia

    International Nuclear Information System (INIS)

    1992-04-01

    In 1992, a clean air strategy will be developed to incorporate views of British Columbians on ways to meet goals related to air quality. A discussion paper is presented to provide information to those interested in participation in developing this strategy. The paper gives information on air quality issues important to the province, including local air quality, urban smog, ozone layer depletion, and global climate change. The views and concerns expressed by stakeholders who attended the Clean Air Conference in 1991 are summarized. The process used to develop the clean air strategy is outlined and some outcomes to be anticipated from the strategy are suggested, including policies and priorities for action to ensure clean air. Air pollutants of concern are total reduced sulfur, mainly from pulp mills and gas processing plants; smoke from wood burning; sulfur dioxide from pulp mills and gas plants; hydrogen fluoride from aluminum smelting; ground-level ozone in urban areas; and acid rain. Elements of a clean air strategy include a smoke management policy, management strategies for greenhouse gases and ozone smog, ozone layer protection measures, regional air quality management plans, and long-term planning efforts in energy use, transportation modes, community design, and land use. 12 refs., 14 figs., 2 tabs

  15. Gas plant cleaning case history

    Energy Technology Data Exchange (ETDEWEB)

    Woods, B

    1971-03-22

    Basic steps to be taken before using any cleaning method are select a responsible group and give it full responsibility; know the problem, what type of fouling, lab samples, amount of material, time and cost; sell the idea to management; maintain the cleaning equipment; and follow up each cleaning operation. These principles have been applied to advantage in the amine contractor at Taylor, a vessel 60 ft high with 78-in. OD, containing carbon steel deck trays with stainless steel caps. The original attempt to clean with wire scrapers manually involved much lost time and several crews. There was limited space in the tray vessels, design created areas difficult to clean, working conditions were unpleasant, equipment downtime was extended, labor cost was high, and the final result was not satisfactory. Chemical cleaning was substituted, preceded by a water wash. Five hours of caustic wash with a 3% solution at 170$F were followed by a water wash, an acid wash, 1-hr neutralization with a weak soda ash solution, and finally passivation to eliminate iron oxide. For the acid wash, sulfamic acid was found best, in 10% concentration for 4 hr. Cascading was most economical, but flooding has been employed sometimes at 2-1/2 times the cost, to reach all the dark corners.

  16. CURE: Clean use of reactor energy

    International Nuclear Information System (INIS)

    1990-05-01

    This paper presents the results of a joint Westinghouse Hanford Company (Westinghouse Hanford)-Pacific Northwest Laboratory (PNL) study that considered the feasibility of treating radioactive waste before disposal to reduce the inventory of long-lived radionuclides, making the waste more suitable for geologic disposal. The treatment considered here is one in which waste would be chemically separated so that long-lived radionuclides can be treated using specific processes appropriate for the nuclide. The technical feasibility of enhancing repository performance by this type of treatment is considered in this report. A joint Westinghouse Hanford-PNL study group developed a concept called the Clean Use of Reactor Energy (CURE), and evaluated the potential of current technology to reduce the long-lived radionuclide content in waste from the nuclear power industry. The CURE process consists of three components: chemical separation of elements that have significant quantities of long-lived radioisotopes in the waste, exposure in a neutron flux to transmute the radioisotopes to stable nuclides, and packaging of radionuclides that cannot be transmuted easily for storage or geologic disposal. 76 refs., 32 figs., 24 tabs

  17. Chemical radwaste solidification processes

    International Nuclear Information System (INIS)

    Malloy, C.W.

    1979-01-01

    Some of these processes and their problems are briefly reviewed: early cement systems; urea-formaldehyde; Dow solidification process; low-viscosity chemical agents (POLYPAC); and water-extensible polyester. 9 refs

  18. Chemical process safety at fuel cycle facilities

    International Nuclear Information System (INIS)

    Ayres, D.A.

    1997-08-01

    This NUREG provides broad guidance on chemical safety issues relevant to fuel cycle facilities. It describes an approach acceptable to the NRC staff, with examples that are not exhaustive, for addressing chemical process safety in the safe storage, handling, and processing of licensed nuclear material. It expounds to license holders and applicants a general philosophy of the role of chemical process safety with respect to NRC-licensed materials; sets forth the basic information needed to properly evaluate chemical process safety; and describes plausible methods of identifying and evaluating chemical hazards and assessing the adequacy of the chemical safety of the proposed equipment and facilities. Examples of equipment and methods commonly used to prevent and/or mitigate the consequences of chemical incidents are discussed in this document

  19. AN ELECTROLYTIC CIP-CLEANING PROCESS FOR REMOVING IMPURITIES FROM THE INNER SURFACE OF A METALLIC CONTAINER

    DEFF Research Database (Denmark)

    2008-01-01

    The invention relates to a novel electrolytic process for removing impurities from the inner surface of a metallic container. The process is particularly useful for cleaning process reactors used for culturing microorganisms, and storage tanks used for storing metabolites formed in the process...... reactor, as well as containers for dairy products....

  20. The 3R anthracite clean coal technology: Economical conversion of brown coal to anthracite type clean coal by low temperature carbonization pre-treatment process

    Directory of Open Access Journals (Sweden)

    Someus Edward

    2006-01-01

    Full Text Available The preventive pre-treatment of low grade solid fuels is safer, faster, better, and less costly vs. the "end-of-the-pipe" post treatment solutions. The "3R" (Recycle-Reduce-Reuse integrated environment control technology provides preventive pre-treatment of low grade solid fuels, such as brown coal and contaminated solid fuels to achieve high grade cleansed fuels with anthracite and coke comparable quality. The goal of the 3R technology is to provide cost efficient and environmentally sustainable solutions by preventive pre-treatment means for extended operations of the solid fuel combustion power plants with capacity up to 300 MWe power capacities. The 3R Anthracite Clean Coal end product and technology may advantageously be integrated to the oxyfuel-oxy-firing, Foster Wheeler anthracite arc-fired utility type boiler and Heat Pipe Reformer technologies in combination with CO2 capture and storage programs. The 3R technology is patented original solution. Advantages. Feedstock flexibility: application of pre-treated multi fuels from wider fuel selection and availability. Improved burning efficiency. Technology flexibility: efficient and advantageous inter-link to proven boiler technologies, such as oxyfuel and arcfired boilers. Near zero pollutants for hazardous-air-pollutants: preventive separation of halogens and heavy metals into small volume streams prior utilization of cleansed fuels. >97% organic sulphur removal achieved by the 3R thermal pre-treatment process. Integrated carbon capture and storage (CCS programs: the introduction of monolitic GHG gas is improving storage safety. The 3R technology offers significant improvements for the GHG CCS conditions. Cost reduction: decrease of overall production costs when all real costs are calculated. Improved safety: application of preventive measures. For pre-treatment a specific purpose designed, developed, and patented pyrolysis technology used, consisting of a horizontally arranged externally

  1. Study of the petroleum schedules thermal cleaning process from asphalt, ressin and paraffin deposits using low- temperature plasma

    International Nuclear Information System (INIS)

    Samigullin, A D; Galiakbarov, A T; Galiakbarov, R T

    2016-01-01

    Petroleum industry uses large amount of pumping and compression pipes. Carrying out the whole range of repair works requires cleaning of the pipe inner surface from deposits which appeared in it during operation [1]. The task of asphalt, resin and paraffin deposits control remains one of the most essential for the branch. The article deals with thermal method and device for asphalt, resin and paraffin deposits removal from pumping and compression pipes inner surface, describes and provides the device application scope for cleaning the pumping and compression pipes inner surface. To deal with borehole equipment and pipe systems waxing problem various deposit prevention and removal methods are used, including mechanical, thermal, chemical, combined and nonconventional methods. (paper)

  2. Design criteria for the new waste calcining facility at the Idaho Chemical Processing Plant

    International Nuclear Information System (INIS)

    Anderson, F.H.; Bingham, G.E.; Buckham, J.A.; Dickey, B.R.; Slansky, C.M.; Wheeler, B.R.

    1976-01-01

    The New Waste Calcining Facility (NWCF) at the Idaho Chemical Processing Plant (ICPP) is being built to replace the existing fluidized-bed, high-level waste calcining facility (WCF). Performance of the WCF is reviewed, equipment failures in WCF operation are examined, and pilot-plant studies on calciner improvements are given in relation to NWCF design. Design features of the NWCF are given with emphasis on process and equipment improvements. A major feature of the NWCF is the use of remote maintenance facilities for equipment with high maintenance requirements, thereby reducing personnel exposures during maintenance and reducing downtime resulting from plant decontamination. The NWCF will have a design net processing rate of 11.36 m 3 of high-level waste per day, and will incorporate in-bed combustion of kerosene for heating the fluidized bed calciner. The off-gas cleaning system will be similar to that for the WCF

  3. Cleaning Challenges of High-κ/Metal Gate Structures

    KAUST Repository

    Hussain, Muhammad Mustafa; Shamiryan, Denis G.; Paraschiv, Vasile; Sano, Kenichi; Reinhardt, Karen A.

    2010-01-01

    High-κ/metal gates are used as transistors for advanced logic applications to improve speed and eliminate electrical issues associated with polySi and SiO2 gates. Various integration schemes are possible and will be discussed, such as dual gate, gate-first, and gate-last, both of which require specialized cleaning and etching steps. Specific areas of discussion will include cleaning and conditioning of the silicon surface, forming a high-quality chemical oxide, removal of the high-κ dielectric with selectivity to the SiO2 layer, cleaning and residue removal after etching, and prevention of galvanic corrosion during cleaning. © 2011 Scrivener Publishing LLC. All rights reserved.

  4. Cleaning Challenges of High-κ/Metal Gate Structures

    KAUST Repository

    Hussain, Muhammad Mustafa

    2010-12-20

    High-κ/metal gates are used as transistors for advanced logic applications to improve speed and eliminate electrical issues associated with polySi and SiO2 gates. Various integration schemes are possible and will be discussed, such as dual gate, gate-first, and gate-last, both of which require specialized cleaning and etching steps. Specific areas of discussion will include cleaning and conditioning of the silicon surface, forming a high-quality chemical oxide, removal of the high-κ dielectric with selectivity to the SiO2 layer, cleaning and residue removal after etching, and prevention of galvanic corrosion during cleaning. © 2011 Scrivener Publishing LLC. All rights reserved.

  5. A study of drying and cleaning methods used in preparation for fluorescent penetrant inspection - Part II

    International Nuclear Information System (INIS)

    Brasche, L.; Lopez, R.; Larson, B.

    2003-01-01

    Fluorescent penetrant inspection is the most widely used method for aerospace components such as critical rotating components of gas turbine engines. Successful use of FPI begins with a clean and dry part, followed by a carefully controlled and applied FPI process, and conscientious inspection by well trained personnel. A variety of cleaning methods are in use for cleaning of titanium and nickel parts with selection based on the soils or contamination to be removed. Cleaning methods may include chemical or mechanical methods with sixteen different types studied as part of this program. Several options also exist for use in drying parts prior to FPI. Samples were generated and exposed to a range of conditions to study the effect of both drying and cleaning methods on the flaw response of FPI. Low cycle fatigue (LCF) cracks were generated in approximately 40 nickel and 40 titanium samples for evaluation of the various cleaning methods. Baseline measurements were made for each of the samples using a photometer to measure sample brightness and a UVA videomicroscope to capture digital images of the FPI indications. Samples were exposed to various contaminants, cleaned and inspected. Brightness measurements and digital images were also taken to compare to the baseline data. A comparison of oven drying to flash dry in preparation for FPI has been completed and will be reported in Part I. Comparison of the effectiveness of various cleaning methods for the contaminants will be presented in Part II. The cleaning and drying studies were completed in cooperation with Delta Airlines using cleaning, drying and FPI processes typical of engine overhaul processes and equipment. The work was completed as part of the Engine Titanium Consortium and included investigators from Honeywell, General Electric, Pratt and Whitney, and Rolls Royce

  6. A study of drying and cleaning methods used in preparation for fluorescent penetrant inspection - Part I

    International Nuclear Information System (INIS)

    Brasche, L.; Lopez, R.; Larson, B.

    2003-01-01

    Fluorescent penetrant inspection is the most widely used method for aerospace components such as critical rotating components of gas turbine engines. Successful use of FPI begins with a clean and dry part, followed by a carefully controlled and applied FPI process, and conscientious inspection by well trained personnel. A variety of cleaning methods are in use for cleaning of titanium and nickel parts with selection based on the soils or contamination to be removed. Cleaning methods may include chemical or mechanical methods with sixteen different types studied as part of this program. Several options also exist for use in drying parts prior to FPI. Samples were generated and exposed to a range of conditions to study the effect of both drying and cleaning methods on the flaw response of FPI. Low cycle fatigue (LCF) cracks were generated in approximately 40 nickel and 40 titanium samples for evaluation of the various cleaning methods. Baseline measurements were made for each of the samples using a photometer to measure sample brightness and a UVA videomicroscope to capture digital images of the FPI indications. Samples were exposed to various contaminants, cleaned and inspected. Brightness measurements and digital images were also taken to compare to the baseline data. A comparison of oven drying to flash dry in preparation for FPI has been completed and will be reported in Part I. Comparison of the effectiveness of various cleaning methods for the contaminants will be presented in Part II. The cleaning and drying studies were completed in cooperation with Delta Airlines using cleaning, drying and FPI processes typical of engine overhaul processes and equipment. The work was completed as part of the Engine Titanium Consortium and included investigators from Honeywell, General Electric, Pratt and Whitney, and Rolls Royce

  7. Experimental investigation on cleaning of corroded ancient coins using a Nd:YAG laser

    Science.gov (United States)

    Zhu, Huazhong; Lu, Jian; Ni, Xiaowu; Shen, Zhonghua

    2017-05-01

    The objective of the work reported is to study experimentally on the removal of corrosion layer from the ancient coins using laser beam as the conservation tool. With the use of Q-switched Nd:YAG laser radiation at 1064 nm, dry laser cleaning, steam laser cleaning and chemical-assisted laser cleaning were used to find out a more suitable and efficient laser treatment for corrosion removal. Cleaning tests were performed on ancient Chinese coins. Experimental results shows that the dry laser cleaning was not successful at removing all types of corrosion crust. It was possible to remove the outer thicker layer of the corrosion products (typically known as patina), but failed on the thinner layer of cuprite. The steam laser cleaning could decrease the initial removal threshold and improve the removal efficiency especially for the oxidation with powdery structure. As for chemical-assisted laser treatment, the cleaning results demonstrate that the combination of laser and chemical reagent could provide a considerable improvement in corrosion removal compared with the conventional laser treatments. Most of the corrosion contaminant was stripped, even the cuprite layer. Moreover, no secondary pollution was formed on the cleaned surface. X-ray fluorescence was applied to determine the variation of composition of surface layer and bulk metal before and after the coins cleaned. It shows that all of the three laser treatments were efficient to reduce the chlorine concentration on the surface of the coins more than 75%.

  8. NOVEL GAS CLEANING/CONDITIONING FOR INTEGRATED GASIFICATION COMBINED CYCLE

    Energy Technology Data Exchange (ETDEWEB)

    Dennis A. Horazak; Richard A. Newby; Eugene E. Smeltzer; Rachid B. Slimane; P. Vann Bush; James L. Aderhold Jr; Bruce G. Bryan

    2005-12-01

    Development efforts have been underway for decades to replace dry-gas cleaning technology with humid-gas cleaning technology that would maintain the water vapor content in the raw gas by conducting cleaning at sufficiently high temperature to avoid water vapor condensation and would thus significantly simplify the plant and improve its thermal efficiency. Siemens Power Generation, Inc. conducted a program with the Gas Technology Institute (GTI) to develop a Novel Gas Cleaning process that uses a new type of gas-sorbent contactor, the ''filter-reactor''. The Filter-Reactor Novel Gas Cleaning process described and evaluated here is in its early stages of development and this evaluation is classified as conceptual. The commercial evaluations have been coupled with integrated Process Development Unit testing performed at a GTI coal gasifier test facility to demonstrate, at sub-scale the process performance capabilities. The commercial evaluations and Process Development Unit test results are presented in Volumes 1 and 2 of this report, respectively. Two gas cleaning applications with significantly differing gas cleaning requirements were considered in the evaluation: IGCC power generation, and Methanol Synthesis with electric power co-production. For the IGCC power generation application, two sets of gas cleaning requirements were applied, one representing the most stringent ''current'' gas cleaning requirements, and a second set representing possible, very stringent ''future'' gas cleaning requirements. Current gas cleaning requirements were used for Methanol Synthesis in the evaluation because these cleaning requirements represent the most stringent of cleaning requirements and the most challenging for the Filter-Reactor Novel Gas Cleaning process. The scope of the evaluation for each application was: (1) Select the configuration for the Filter-Reactor Novel Gas Cleaning Process, the arrangement of the

  9. Demand driven salt clean-up in a molten salt fast reactor - Defining a priority list.

    Science.gov (United States)

    Merk, B; Litskevich, D; Gregg, R; Mount, A R

    2018-01-01

    The PUREX technology based on aqueous processes is currently the leading reprocessing technology in nuclear energy systems. It seems to be the most developed and established process for light water reactor fuel and the use of solid fuel. However, demand driven development of the nuclear system opens the way to liquid fuelled reactors, and disruptive technology development through the application of an integrated fuel cycle with a direct link to reactor operation. The possibilities of this new concept for innovative reprocessing technology development are analysed, the boundary conditions are discussed, and the economic as well as the neutron physical optimization parameters of the process are elucidated. Reactor physical knowledge of the influence of different elements on the neutron economy of the reactor is required. Using an innovative study approach, an element priority list for the salt clean-up is developed, which indicates that separation of Neodymium and Caesium is desirable, as they contribute almost 50% to the loss of criticality. Separating Zirconium and Samarium in addition from the fuel salt would remove nearly 80% of the loss of criticality due to fission products. The theoretical study is followed by a qualitative discussion of the different, demand driven optimization strategies which could satisfy the conflicting interests of sustainable reactor operation, efficient chemical processing for the salt clean-up, and the related economic as well as chemical engineering consequences. A new, innovative approach of balancing the throughput through salt processing based on a low number of separation process steps is developed. Next steps for the development of an economically viable salt clean-up process are identified.

  10. [Cleaning and disinfection in nursing homes. Data on quality of structure, process and outcome in nursing homes in Frankfurt am Main, Germany, 2011].

    Science.gov (United States)

    Heudorf, U; Gasteyer, S; Samoiski, Y; Voigt, K

    2012-08-01

    Due to the Infectious Disease Prevention Act, public health services in Germany are obliged to check the infection prevention in hospitals and other medical facilities as well as in nursing homes. In Frankfurt/Main, Germany, standardized control visits have been performed for many years. In 2011 focus was laid on cleaning and disinfection of surfaces. All 41 nursing homes were checked according to a standardized checklist covering quality of structure (i.e. staffing, hygiene concept), quality of process (observation of the cleaning processes in the homes) and quality of output, which was monitored by checking the cleaning of fluorescent marks which had been applied some days before and should have been removed via cleaning in the following days before the final check. In more than two thirds of the homes, cleaning personnel were salaried, in one third external personnel were hired. Of the homes 85% provided service clothing and all of them offered protective clothing. All homes had established hygiene and cleaning concepts, however, in 15% of the homes concepts for the handling of Norovirus and in 30% concepts for the handling of Clostridium difficile were missing. Regarding process quality only half of the processes observed, i.e. cleaning of hand contact surfaces, such as handrails, washing areas and bins, were correct. Only 44% of the cleaning controls were correct with enormous differences between the homes (0-100%). The correlation between quality of process and quality of output was significant. There was good quality of structure in the homes but regarding quality of process and outcome there was great need for improvement. This was especially due to faults in communication and coordination between cleaning personnel and nursing personnel. Quality outcome was neither associated with the number of the places for residents nor with staffing. Thus, not only quality of structure but also quality of process and outcome should be checked by the public health

  11. PROBIOTIC CLEANING PREPARATIONS VERSUS CHEMICAL DISINFECTANTS

    Directory of Open Access Journals (Sweden)

    W. Luepcke

    2017-12-01

    Full Text Available Probiotic detergents are increasingly used and are a real alternative for limiting the use of chemical cleaners, chemical disinfectants and antibiotics. They therefore have a great future because they contribute to animal health, to the hygienic production of food products of animal origin and to their harmlessness and to consumer health and environmental protection where they even have a beneficial effect on the microflora apart from chemical disinfectants that have a negative impact and destroy the beneficial microflora.

  12. Fouling and cleaning of seawater reverse osmosis membranes in Kalpakkam Nuclear Desalination Plant

    International Nuclear Information System (INIS)

    Murugan, V.; Rajanbabu, K.; Tiwari, S.A.; Balasubramanian, C.; Yadav, Manoj Kumar; Dangore, A.Y.; Prabhakar, S.; Tewari, P.K.

    2005-01-01

    Seawater reverse osmosis plant of 1800 m 3 /day capacity is a part of 6300 m 3 /day capacity Nuclear Desalination Demonstration Project, at Kalpakkam. The plant was commissioned in October 2002 and is in continuous operation. This paper deals with types of foulants, membrane cleaning procedures and the improvement in the reverse osmosis system after cleaning. This paper also describes analysis of foulants which may consist of adsorbed organic compounds, particulate matter, microorganisms, metallic oxides and chemical cleaning procedure to be adopted, which is characteristics of sea water used as the membrane foulant is very much specific with respect to the sea water constituents. The cleaning of the membranes in Kalpakkam Nuclear Desalination plant were taken up as the quality of permeate deteriorated and differential pressure across membrane had gone-up. This paper essentially deals with selection of cleaning chemicals, the experience gained in cleaning procedure adopted and effects of cleaning for the membrane system. (author)

  13. Determination of properties of clean coal technology post-process residue

    Directory of Open Access Journals (Sweden)

    Agnieszka Klupa

    2016-01-01

    Full Text Available This article presents the possibilities of using modern measuring devices to determine the properties of process residues (Polish acronym: UPP. UPP was taken from the combustion process from a power plant in Silesia. Determining the properties of UPP is the basis for making decisions about its practical application, for example, as a raw material to obtain useful products such as: pozzolan, cenosphere or zeolite, for which there is demand. The development of advanced technology and science has given rise to modern and precise research tools that contribute to the development of appropriate methods to assess the properties of post-process residue. For this study the following were used: scanning electron microscope with EDS microanalysis and an analyzer for particle size-, shape- and number- analysis. The study conducted confirms the effectiveness of SEM analysis to determine the properties of post-process residue from Clean Coal Technologies (CCT. The results obtained are an introduction to further research on the determination of properties of CCT post-process residue. Research to determine the properties of CCT post-process residue only began relatively recently.

  14. MSO spent salt clean-up recovery process; TOPICAL

    International Nuclear Information System (INIS)

    Adamson, M G; Brummond, W A; Hipple, D L; Hsu, P C; Summers, L J; Von Holtz, E H; Wang, F T

    1997-01-01

    An effective process has been developed to separate metals, mineral residues, and radionuclides from spent salt, a secondary waste generated by Molten Salt Oxidation (MSO). This process includes salt dissolution, pH adjustment, chemical reduction and/or sulfiding, filtration, ion exchange, and drying. The process uses dithionite to reduce soluble chromate and/or sulfiding agent to suppress solubilities of metal compounds in water. This process is capable of reducing the secondary waste to less than 5% of its original weight. It is a low temperature, aqueous process and has been demonstrated in the laboratory[1

  15. Chemical surface modification of glass beads for the treatment of paper machine process waters

    International Nuclear Information System (INIS)

    Jradi, Khalil; Daneault, Claude; Chabot, Bruno

    2011-01-01

    Adsorption of detrimental contaminants on a solid sorbent is proposed to remove these contaminants from process waters to increase water recycling and reduce effluent loads in the papermaking industry. A self-assembly process of attaching (covalent grafting) cationic aminosilane molecules to glass beads was investigated. The existence and the hydrolytic stability of self-assembled monolayers and multilayers were confirmed by X-Ray Photoelectron Spectroscopy and contact angle measurements. Effects of reaction time and curing on aminosilane layer structures are also discussed. The curing step after silanization seems to be crucial in the hydrophobization of the quaternary ammonium silane coated onto glass beads, and curing could affect the final chemical structure of the ammonium groups of grafted organosilane. Results indicated that modified glass beads have a strong hydrophobicity, which is attributed to the hydrophobic property of the longest carbon chain grafted onto the glass surface. Adsorption of a model contaminant (stearic acid) onto chemically modified glass beads was determined using colloidal titration. Hydrophobic interactions could be the main driving force involved between the long carbon chains of stearic acid and the carbon chains of the aminosilane layers on glass bead surfaces. Finally, self-assembly processes applied onto glass beads may have two promising applications for papermaking and self-cleaning systems.

  16. Surface cleaning in thin film technology

    International Nuclear Information System (INIS)

    Mattox, D.M.

    1978-01-01

    A ''clean surface'' is one that contains no significant amounts of undesirable material. This paper discusses the types and origin of various contaminants. Since cleaning is often equated with adhesion, the mechanisms of adhesion to oxide, metal, and organic surfaces are reviewed and cleaning processes for these surfaces are outlined. Techniques for monitoring surface cleaning are presented, and the importance of storage of clean surfaces is discussed. An extensive bibliography is given. 4 figs., 89 references

  17. Coal preparation and coal cleaning in the dry process; Kanshiki sentaku to coal cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Z; Morikawa, M; Fujii, Y [Okayama University, Okayama (Japan). Faculty of Engineering

    1996-09-01

    Because the wet process has a problem such as waste water treatment, coal cleaning in the dry process was discussed. When a fluidized bed (using glass beads and calcium carbonate) is utilized instead of the heavy liquid, the fluidized bed will have apparent density as the liquid does, whereas the relative relationship therewith determines whether a substance having been put into the fluidized bed will float or sink. This is utilized for coals. In addition, two powder constituents of A and B may be wanted to be separated using the fluidized extraction process (similar to the liquid-liquid extraction process). In such a case, a fluidized bed in which both constituents are mixed is added with a third constituent C (which will not mix with A, but mix well with B), where the constituents are separated into A and (B + C), and the (B + C) constituent is separated further by using a sieve. If coal has the coal content mixed with ash content and pulverized, it turns into particle groups which have distributions in grain size and density. Groups having higher density may contain more ash, and those having lower density less ash. In addition, the ash content depends also on the grain size. The ash content may be classified by using simultaneously wind classification (for density and grain size) and a sieve (for grain size). This inference may be expanded to consideration of constructing a multi-stage fluidized bed classification tower. 12 figs., 5 tabs.

  18. Alkali-assisted membrane cleaning for fouling control of anaerobic ceramic membrane bioreactor.

    Science.gov (United States)

    Mei, Xiaojie; Quek, Pei Jun; Wang, Zhiwei; Ng, How Yong

    2017-09-01

    In this study, a chemically enhanced backflush (CEB) cleaning method using NaOH solution was proposed for fouling mitigation in anaerobic membrane bioreactors (AnMBRs). Ex-situ cleaning tests revealed that NaOH dosages ranging from 0.05 to 1.30mmol/L had positive impacts on anaerobic biomass, while higher dosages (>1.30mmol/L) showed inhibition and/or toxic impacts. In-situ cleaning tests showed that anaerobic biomass could tolerate much higher NaOH concentrations due to the alkali consumption by anaerobic process and/or the buffering role of mixed liquor. More importantly, 10-20mmol-NaOH/L could significantly reduce membrane fouling rates (4-5.5 times over the AnMBR with deionized water backflush) and slightly improve methanogenic activities. COD removal efficiencies were over 87% and peaked at 20mmol-NaOH/L. However, extremely high NaOH concentration had adverse effects on filtration and treatment performance. Economic analysis indicated that 12mmol/L of NaOH was the cost-efficient and optimal fouling-control dosage for the CEB cleaning. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Atmosphere self-cleaning under humidity conditions and influence of the snowflakes and artificial light interaction for water dissociation simulated by the means of COMSOL

    Science.gov (United States)

    Cocean, A.; Cocean, I.; Cazacu, M. M.; Bulai, G.; Iacomi, F.; Gurlui, S.

    2018-06-01

    The self-cleaning of the atmosphere under humidity conditions is observed due to the change in emission intensity when chemical traces are investigated with DARLIOES - the advanced LIDAR based on space- and time-resolved RAMAN and breakdown spectroscopy in conditions of consistent humidity of atmosphere. The determination was performed during the night, in the wintertime under conditions of high humidity and snowfall, in urban area of Iasi. The change in chemical composition of the atmosphere detected was assumed to different chemical reactions involving presence of the water. Water dissociation that was registered during spectral measurements is explained by a simulation of the interaction between artificial light and snowflakes - virtually designed in a spherical geometry - in a wet air environment, using COMSOL Multiphysics software. The aim of the study is to explain the decrease or elimination of some of the toxic trace chemical compounds in the process of self-cleaning in other conditions than the sun light interaction for further finding application for air cleaning under artificial conditions.

  20. 2000 Annual report NATO/CCMS Pilot Study, Clean Products and Processes (Phase I)

    DEFF Research Database (Denmark)

    Wenzel, Henrik; Molin, Christine; Hauschild, Michael Zwicky

    2001-01-01

    The NATO/Committee on the Challenges of Modern Society third Pilot Study meeting on Clean Products and Processes was held in Copenhagen, Denmark on May 7-12, 2000. This meeting maintained the momentum generated during the of the first two years of the pilot study, focusing on progress made on sev...... homepage....

  1. Experimental study on air cleaning effect of clean air heat pump and its impact on ventilation requirement

    DEFF Research Database (Denmark)

    Fang, Lei; Sheng, Ying; Nie, Jinzhe

    2017-01-01

    This study investigated air purification effect of a Clean-Air Heat Pump (CAHP) which combined a desiccant wheel with a heat pump for both air cleaning and HVAC of buildings. The experiment was conducted in a field lab at four different outdoor air supply rates with and without air cleaning by CAHP....... Both sensory assessments of perceived air quality and chemical measurements of TVOC concentrations were conducted for evaluating the air cleaning performance of the CAHP. The results of experiment showed that running the CAHP improved significantly perceived air quality. At 2 L/s per person of outdoor...... air supply rate with operating the CAHP, the air quality was equivalent to the value at the higher outdoor air supply rate of 10 L/s per person without running CAHP. The TVOC measurements observed over 92% of efficiency on removal of indoor air VOCs and no VOCs accumulation on the desiccant wheel...

  2. Offgas system particulate cleaning test and evaluation for the process experimental pilot plant

    International Nuclear Information System (INIS)

    Ayers, A.L. Jr.; Gale, L.G.; Stermer, D.L.

    1990-01-01

    The process experimental pilot plant (PREPP) incinerates mixed solid waste. The exhaust gas is processed through a wet offgas cleaning system. Rapid loading of the exhaust filters has been a problem and an important contributing factor is the use of quench solution containing a relatively high concentration of dissolved solids. The dissolved solids are released as a submicron particulate when the quench solution evaporates. A series of tests were performed to better identify the nature of the problem and explore solutions to the problem involving modifications to the quench process

  3. Offgas system particulate cleaning test and evaluation for the Process Experimental Pilot Plant

    International Nuclear Information System (INIS)

    Ayers, A.L. Jr.; Gale, L.G.; Stermer, D.L.

    1990-01-01

    The Process Experimental Pilot Plant (PREPP) incinerates mixed solid waste. The exhaust gas is processed through a wet offgas cleaning system. Rapid loading of the exhaust filters has been a problem and an important contributing factor is the use of a quench solution containing a relatively high concentration of dissolved solids. The dissolved solids are released as a submicron particulate when the quench solution evaporates. A series of tests were performed to better identify the nature of the problem and explore solutions to the problem involving modifications to the quench process. 2 refs., 7 figs

  4. Cleaning results of new and fouled nanofiltration membrane characterized by contact angle, updated DSPM, flux and salts rejection

    International Nuclear Information System (INIS)

    Al-Amoudi, Ahmed; Williams, Paul; Al-Hobaib, A.S.; Lovitt, Robert W.

    2008-01-01

    In membrane process industries, membrane cleaning is one of the most important concerns from both economical and scientific points of view. Though cleaning is important to recover membrane performance, an inappropriate selection of cleaning agents may result into unsatisfactory cleaning or irreparable membrane. In this study the cleaning performance has been studied with measurements of membrane contact angle, Updated Donnan steric partitioning pore model (UDSPM) and salt rejection as well as flux measurement. Thin film nanofiltration (NF) membranes such as DK, HL and DL provided by GE Osmonics are used in this study. Tests were carried out with virgin DK, HL and DL as well as fouled DK membranes. Several cleaning agents were investigated; some of them were analytical grade such as HCl, NaOH and others such as SDS, mix agents were commercial grade agents that are already in use in commercial plants. Contact angle, DSPM and salt rejection as well as flux of virgin and fouled membranes before and after chemical cleaning were measured and compared. The contact angle measurements with and without chemical cleaning of different virgin and fouled membranes revealed very interesting results which may be used to characterise the membrane surface cleanliness. The contact angle results revealed that the cleaning agents are found to modify membrane surface properties (hydrophobicity/hydrophilicity) of the treated and untreated virgin and fouled membranes. The details of these results were also investigated and are reported in the paper. However, UDSPM method did not give any valuable information about pore size of the untreated and treated NF membranes. The salt rejection level of monovalent and divalent ions before and after cleaning by high and low pH cleaning agents is also investigated and is reported in the paper

  5. Cleaning results of new and fouled nanofiltration membrane characterized by contact angle, updated DSPM, flux and salts rejection

    Energy Technology Data Exchange (ETDEWEB)

    Al-Amoudi, Ahmed [Centre for complex fluids processing, Multidisciplinary Nanotechnology Centre, School of Engineering, University of Wales, Swansea SA2 8PP (United Kingdom) and Saline Water Conversion Corporation (SWCC), Saline Water Desalination Research Institute Staff (Saudi Arabia)], E-mail: 310981@swan.ac.uk; Williams, Paul [Centre for complex fluids processing, Multidisciplinary Nanotechnology Centre, School of Engineering, University of Wales, Swansea SA2 8PP (United Kingdom); Al-Hobaib, A.S. [Institute of Atomic Energy Research, King Abdulaziz City for Science And Technology, P.O. Box 6086, Riyadh 11442 (Saudi Arabia); Lovitt, Robert W. [Centre for complex fluids processing, Multidisciplinary Nanotechnology Centre, School of Engineering, University of Wales, Swansea SA2 8PP (United Kingdom)

    2008-04-30

    In membrane process industries, membrane cleaning is one of the most important concerns from both economical and scientific points of view. Though cleaning is important to recover membrane performance, an inappropriate selection of cleaning agents may result into unsatisfactory cleaning or irreparable membrane. In this study the cleaning performance has been studied with measurements of membrane contact angle, Updated Donnan steric partitioning pore model (UDSPM) and salt rejection as well as flux measurement. Thin film nanofiltration (NF) membranes such as DK, HL and DL provided by GE Osmonics are used in this study. Tests were carried out with virgin DK, HL and DL as well as fouled DK membranes. Several cleaning agents were investigated; some of them were analytical grade such as HCl, NaOH and others such as SDS, mix agents were commercial grade agents that are already in use in commercial plants. Contact angle, DSPM and salt rejection as well as flux of virgin and fouled membranes before and after chemical cleaning were measured and compared. The contact angle measurements with and without chemical cleaning of different virgin and fouled membranes revealed very interesting results which may be used to characterise the membrane surface cleanliness. The contact angle results revealed that the cleaning agents are found to modify membrane surface properties (hydrophobicity/hydrophilicity) of the treated and untreated virgin and fouled membranes. The details of these results were also investigated and are reported in the paper. However, UDSPM method did not give any valuable information about pore size of the untreated and treated NF membranes. The salt rejection level of monovalent and divalent ions before and after cleaning by high and low pH cleaning agents is also investigated and is reported in the paper.

  6. Temperature control of thermal-gas-dynamical installation in cleaning oil-well tubes

    Science.gov (United States)

    Penner, V. A.; Martemyanov, D. B.; Pshenichnikova, V. V.

    2017-08-01

    The article provides the study results of cleaning oil-well tubes, the oil-well tube failure reasons for service by their types have been considered. The chemical method of cleaning oil-well tubes as the least expensive has been reviewed when acid solution moves to the interptube space mixing up with oil and liquidates paraffin and pitches deposits on the internal pipe surface. Except the chemical method of pipes cleaning the mechanical one was considered as well. Also the disadvantages -such as the low productivity of cleaning and design complexity- of this deposits removal method on the internal oil-well tube surface have been considered. An effective method for cleaning oil-well tubing from paraffin and pitches by the thermodynamic plant based on the aircraft engine has been introduced for the first time. The temperature distribution graph in the gas stream at the engine output has been given.

  7. Coupling Computer-Aided Process Simulation and ...

    Science.gov (United States)

    A methodology is described for developing a gate-to-gate life cycle inventory (LCI) of a chemical manufacturing process to support the application of life cycle assessment in the design and regulation of sustainable chemicals. The inventories were derived by first applying process design and simulation of develop a process flow diagram describing the energy and basic material flows of the system. Additional techniques developed by the U.S. Environmental Protection Agency for estimating uncontrolled emissions from chemical processing equipment were then applied to obtain a detailed emission profile for the process. Finally, land use for the process was estimated using a simple sizing model. The methodology was applied to a case study of acetic acid production based on the Cativa tm process. The results reveal improvements in the qualitative LCI for acetic acid production compared to commonly used databases and top-down methodologies. The modeling techniques improve the quantitative LCI results for inputs and uncontrolled emissions. With provisions for applying appropriate emission controls, the proposed method can provide an estimate of the LCI that can be used for subsequent life cycle assessments. As part of its mission, the Agency is tasked with overseeing the use of chemicals in commerce. This can include consideration of a chemical's potential impact on health and safety, resource conservation, clean air and climate change, clean water, and sustainable

  8. Industrial rag cleaning process for the environmentally safe removal of petroleum-based solvents

    International Nuclear Information System (INIS)

    Fierro, J.V.

    1993-01-01

    A process for the cleaning of industrial rags contaminated with environmentally unsafe petroleum-based solvent is described, comprising the step of: (a) placing a load of the industrial rags in a mechanically driven rotary drum; (b) revolving the drum at a high speed sufficient to physically extract liquid petroleum-based solvent contaminate from the industrial rags; (c) routing the extracted petroleum-based solvent contaminate from the rotary drum to a waste solvent collection line for environmentally safe disposal; (d) revolving the rotary drum to cause a tumbling of the industrial rags while maintaining the temperature within the drum at below the flash point of the petroleum-based solvent; (e) intermittently forcing cold air and hot air through the rotary drum to vaporize solvent from the industrial rags; (f) routing the vaporized petroleum-based solvent contaminant from the rotary drum to a condenser wherein the petroleum-based solvent contaminate is condensed and thereafter further routing said condensed solvent to a waste collection line for environmentally safe disposal; and (g) cleaning the industrial rags in the presence of a dry cleaning solvent to remove residual petroleum-based solvents and soil

  9. Two-step chemical decontamination technology

    International Nuclear Information System (INIS)

    Rankin, W.N.

    1992-01-01

    An improved two-step chemical decontamination technique was recently developed at INEL. This memorandum documents the addition of this technology to the SRTC arsenal of decontamination technology. A two-step process using NAOH, KMnO 4 followed by HNO 3 was used for cleaning doorstops (small casks) in the SRTC High Level Caves in 1967. Subsequently, more aggressive chemical techniques have been found to be much more effective for our applications. No further work on two-step technology is planned

  10. Chemical process control using Mat lab

    International Nuclear Information System (INIS)

    Kang, Sin Chun; Kim, Raeh Yeon; Kim, Yang Su; Oh, Min; Yeo, Yeong Gu; Jung, Yeon Su

    2001-07-01

    This book is about chemical process control, which includes the basis of process control with conception, function, composition of system and summary, change of laplace and linearization, modeling of chemical process, transfer function and block diagram, the first dynamic property of process, the second dynamic property of process, the dynamic property of combined process, control structure of feedback on component of control system, the dynamic property of feedback control loop, stability of closed loop control structure, expression of process, modification and composition of controller, analysis of vibration response and adjustment controller using vibration response.

  11. Decontamination of polypropylene fabrics by dry cleaning

    International Nuclear Information System (INIS)

    Severa, J.; Knajfl, J.

    1983-01-01

    Polypropylene fabrics can efficiently be decontaminated by dry cleaning in benzine or perchloroethylene, this also in case the fabric was greased in addition to radioactive contamination. For heavily soiled fabric, it is advantageous to first dry clean it and then wash it. The positive effect was confirmed of intensifiers on the cleaning process, especially of benzine soap. In practice, its concentration should be selected within 1 and 10 g.dm - 3 . Decontamination by dry cleaning and subsequent washing is advantageous in that that the resulting activity of waste water from the laundry is low. Radioactive wastes from the dry cleaning process have a low weight and can be handled as solid waste. (M.D.)

  12. Industrial use of coal and clean coal technology

    Energy Technology Data Exchange (ETDEWEB)

    Leibson, I; Plante, J J.M.

    1990-06-01

    This report builds upon two reports published in 1988, namely {ital The use of Coal in the Industrial, Commercial, Residential and Transportation Sectors} and {ital Innovative Clean Coal Technology Deployment}, and provides more specific recommendations pertaining to coal use in the US industrial sector. The first chapter addresses industrial boilers which are common to many industrial users. The subsequent nine chapters cover the following: coke, iron and steel industries; aluminium and other metals; glass, brick, ceramic, and gypsum industries; cement and lime industries; pulp and paper industry; food and kindred products; durable goods industry; textile industry; refining and chemical industry. In addition, appendices supporting the contents of the study are provided. Each chapter covers the following topics as applicable: energy overview of the industry sector being discussed; basic processes; foreign experience; impediments to coal use; incentives that could make coal a fuel of choice; current and projected use of clean coal technology; identification of coal technology needs; conclusions; recommendations.

  13. TiO 2 Thin Films Prepared via Adsorptive Self-Assembly for Self-Cleaning Applications

    KAUST Repository

    Xi, Baojuan

    2012-02-22

    Low-cost controllable solution-based processes for preparation of titanium oxide (TiO 2) thin films are highly desirable, because of many important applications of this oxide in catalytic decomposition of volatile organic compounds, advanced oxidation processes for wastewater and bactericidal treatments, self-cleaning window glass for green intelligent buildings, dye-sensitized solar cells, solid-state semiconductor metal-oxide solar cells, self-cleaning glass for photovoltaic devices, and general heterogeneous photocatalysis for fine chemicals etc. In this work, we develop a solution-based adsorptive self-assembly approach to fabricate anatase TiO 2 thin films on different glass substrates such as simple plane glass and patterned glass at variable compositions (normal soda lime glass or solar-grade borofloat glass). By tuning the number of process cycles (i.e., adsorption-then-heating) of TiO 2 colloidal suspension, we could facilely prepare large-area TiO 2 films at a desired thickness and with uniform crystallite morphology. Moreover, our as-prepared nanostructured TiO 2 thin films on glass substrates do not cause deterioration in optical transmission of glass; instead, they improve optical performance of commercial solar cells over a wide range of incident angles of light. Our as-prepared anatase TiO 2 thin films also display superhydrophilicity and excellent photocatalytic activity for self-cleaning application. For example, our investigation of photocatalytic degradation of methyl orange indicates that these thin films are indeed highly effective, in comparison to other commercial TiO 2 thin films under identical testing conditions. © 2012 American Chemical Society.

  14. Optimizing UF Cleaning in UF-SWRO System Using Red Sea Water

    KAUST Repository

    Bahshwan, Mohanad

    2012-07-01

    Increasing demand for fresh water in arid and semi-arid areas, similar to the Middle East, pushed for the use of seawater desalination techniques to augment freshwater. Seawater Reverse Osmosis (SWRO) is one of the techniques that have been commonly used due to its cost effectiveness. Recently, the use of Ultrafiltration (UF) was recommended as an effective pretreatment for SWRO membranes, as opposed to conventional methods (i.e. sand filtration). During UF operation, intermittent cleaning is required to remove particles and contaminants from the membrane\\'s surface and pores. The different cleaning steps consume chemicals and portion of the product water, resulting in a decrease in the overall effectiveness of the process and hence an increase in the production cost. This research focused on increasing the plant\\'s efficiency through optimizing the cleaning protocol without jeopardizing the effectiveness of the cleaning process. For that purpose, the design of experiment (DOE) focused on testing different combinations of these cleaning steps while all other parameters (such as filtration flux or backwash flux) remained constant. The only chemical used was NaOCI during the end of each experiment to restore the trans-membrane pressure (TMP) to its original state. Two trains of Dow™ Ultrafiltration SFP-2880 were run in parallel for this study. The first train (named UF1) was kept at the manufacturer\\'s recommended cleaning steps and frequencies, while the second train (named UF2) was varied according to the DOE. The normalized final TMP was compared to the normalized initial TMP to measure the fouling rate of the membrane at the end of each experiment. The research was supported by laboratory analysis to investigate the cause of the error in the data by analyzing water samples collected at different locations. Visual inspection on the results from the control unit showed that the data cannot be reproduced with the current feed water quality. Statistical analysis

  15. Exhaust gas clean up process

    Science.gov (United States)

    Walker, R.J.

    1988-06-16

    A method of cleaning an exhaust gas containing particulates, SO/sub 2/ and NO/sub x/ is described. The method involves prescrubbing with water to remove HCl and most of the particulates, scrubbing with an aqueous absorbent containing a metal chelate and dissolved sulfite salt to remove NO/sub x/ and SO/sub 2/, and regenerating the absorbent solution by controlled heating, electrodialysis and carbonate salt addition. The NO/sub x/ is removed as N/sub 2/ gas or nitrogen sulfonate ions and the oxides of sulfur are removed as a valuable sulfate salt. 4 figs.

  16. Atomic hydrogen cleaning of GaAs photocathodes

    International Nuclear Information System (INIS)

    Poelker, M.; Price, J.; Sinclair, C.

    1997-01-01

    It is well known that surface contaminants on semiconductors can be removed when samples are exposed to atomic hydrogen. Atomic H reacts with oxides and carbides on the surface, forming compounds that are liberated and subsequently pumped away. Experiments at Jefferson lab with bulk GaAs in a low-voltage ultra-high vacuum H cleaning chamber have resulted in the production of photocathodes with high photoelectron yield (i.e., quantum efficiency) and long lifetime. A small, portable H cleaning apparatus also has been constructed to successfully clean GaAs samples that are later removed from the vacuum apparatus, transported through air and installed in a high-voltage laser-driven spin-polarized electron source. These results indicate that this method is a versatile and robust alternative to conventional wet chemical etching procedures usually employed to clean bulk GaAs

  17. Are safety data sheets for cleaning products used in Norway a factor contributing to the risk of workers exposure to chemicals?

    Directory of Open Access Journals (Sweden)

    Abdulqadir M. Suleiman

    2014-10-01

    Full Text Available Objectives: Cleaning products are considered less hazardous than those used in other sectors. Suppliers and distributors are less conscientious when it comes to informing users on health risks. The aim of the study was to elaborate on the usefulness and clarity of information in the safety data sheets (SDS for cleaning products, and considering if the use of these SDSs can be seen as a risk factor towards occupational exposure to hazardous chemicals in the sector. Material and Methods: Safety data sheets were selected based on the risk level of the product assigned in an industrial sector scheme. 320 SDSs for cleaning products were reviewed. Constituent components found in the products over a given threshold were listed and available information thereof used to assess the perceived non-hazard consideration of the chemicals. Results: The contents of the SDSs was generic and mostly incomplete. Safety measures and health information lacked sufficient specificity despite varying compositions and concentrations of components. There is generally incompatibility between mentioned sections on the suggested non-hazardous nature of the products and health effects. Not all substances used in these products have harmonized classifications, which makes them open to various classification of the products and the suggested safety measures. This results in different companies classifying similar products differently. Risk management measures and suggested personal protective equipment (PPEs are given haphazardly. Physical properties relevant to risk assessment are not included. Conclusions: The safety data sheets are ambiguous, and they lack relevant and important information. Inadequate information and risk assessment concerning the products can lead to workers being exposed to hazardous chemicals. Underestimation of the hazard contribution of the components of the products and the insufficient, non-objective mention of appropriate control and protective

  18. Clean Slate 2 Revegetation and Monitoring Plan

    International Nuclear Information System (INIS)

    David Anderson

    1998-01-01

    This document is a reclamation plan for short-term and long-term stabilization of land disturbed by activities associated with interim clean-up of radionuclide-contaminated surface soil at Clean Slate 2 located northwest of the Nevada Test Site on the Nellis Air Force Range. Surface soils at Clean Slate 2 were contaminated as a result of the detonation of a device containing plutonium and depleted uranium using chemical explosives. Excavation of contaminated soils at Clean Slate 2 will follow procedures similar to those used during the cleanup of the Double Tracks and Clean Slate 1 sites. A maximum of approximately 33 cm (12 in) of the surface soils will be excavated and removed from the site. Near ground zero, where contamination levels are highest, approximately 2 m (7 ft) of soil may be removed. The maximum area to be excavated is estimated to be 18.4 hectares (45.4) acres. In addition to the disturbance associated with soil excavation, approximately 2.0 hectares (5.0) acres will be disturbed by the construction of staging areas and placement of support facilities. Short term stabilization consists of an application of a chemical soil stabilizer and long-term stabilizations involves the establishment of a permanent vegetative cover using selective native plant species, site preparation techniques, increasing organic matter and water holding capacity, irrigation to ensure seed germination and plant establishment. The cleanup site will be monitored to ensure success of revegetation and resuspension of soil particles is within established limits

  19. Fluorescent Penetrant INSPECTION—CLEANING Study Update

    Science.gov (United States)

    Eisenmann, D.; Brasche, L.

    2009-03-01

    Fluorescent penetrant inspection (FPI) is widely used in the aviation industry and other industries for surface-breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. There is variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. Before the FPI process begins, components are cleaned using a variety of cleaning methods which are selected based on the alloy and the soil types which must be removed. It is also important that the cleaning process not adversely affect the FPI process. From the first three phases of this project it has been found that a hot water rinse can aid in the detection process when using this nondestructive method.

  20. Applications of Process Synthesis: Moving from Conventional Chemical Processes towards Biorefinery Processes

    DEFF Research Database (Denmark)

    Yuan, Zhihong; Chen, Bingzhen; Gani, Rafiqul

    2013-01-01

    Concerns about diminishing petroleum reserves, enhanced worldwide demand for fuels and fluctuations in the global oil market, together with climate change and national security have promoted many initiatives for exploring alternative, non-petroleum based processes. Among these initiatives......, biorefinery processes for converting biomass-derived carbohydrates into transportation fuels and chemicals are now gaining more and more attention from both academia and industry. Process synthesis, which has played a vital role for the development, design and operation of (petro) chemical processes, can...

  1. Characterization of Cleaning and Disinfecting Tasks and Product Use Among Hospital Occupations

    Science.gov (United States)

    Saito, Rena; Virji, M. Abbas; Henneberger, Paul K.; Humann, Michael J.; LeBouf, Ryan F.; Stanton, Marcia L.; Liang, Xiaoming; Stefaniak, Aleksandr B.

    2016-01-01

    Background Healthcare workers have an elevated prevalence of asthma and related symptoms associated with the use of cleaning/disinfecting products. The objective of this study was to identify and characterize cleaning/disinfecting tasks and products used among hospital occupations. Methods Workers from 14 occupations at five hospitals were monitored for 216 shifts, and work tasks and products used were recorded at five-minute intervals. The major chemical constituents of each product were identified from safety data sheets. Results Cleaning and disinfecting tasks were performed with a high frequency at least once per shift in many occupations. Medical equipment preparers, housekeepers, floor strippers/waxers, and endoscopy technicians spent on average 108–177 min/shift performing cleaning/disinfecting tasks. Many occupations used products containing amines and quaternary ammonium compounds for > 100 min/shift. Conclusions This analysis demonstrates that many occupations besides housekeeping incur exposures to cleaning/disinfecting products, albeit for different durations and using products containing different chemicals. PMID:25351791

  2. Hierarchical surfaces for enhanced self-cleaning applications

    Science.gov (United States)

    Fernández, Ariadna; Francone, Achille; Thamdrup, Lasse H.; Johansson, Alicia; Bilenberg, Brian; Nielsen, Theodor; Guttmann, Markus; Sotomayor Torres, Clivia M.; Kehagias, Nikolaos

    2017-04-01

    In this study we present a flexible and adaptable fabrication method to create complex hierarchical structures over inherently hydrophobic resist materials. We have tested these surfaces for their superhydrophobic behaviour and successfully verified their self-cleaning properties. The followed approach allow us to design and produce superhydrophobic surfaces in a reproducible manner. We have analysed different combination of hierarchical micro-nanostructures for their application to self-cleaning surfaces. A static contact angle value of 170° with a hysteresis of 4° was achieved without the need of any additional chemical treatment on the fabricated hierarchical structures. Dynamic effects were analysed on these surfaces, obtaining a remarkable self-cleaning effect as well as a good robustness over impacting droplets.

  3. Clean coal technologies

    International Nuclear Information System (INIS)

    Aslanyan, G.S.

    1993-01-01

    According to the World Energy Council (WEC), at the beginning of the next century three main energy sources - coal, nuclear power and oil will have equal share in the world's total energy supply. This forecast is also valid for the USSR which possesses more than 40% of the world's coal resources and continuously increases its coal production (more than 700 million tons of coal are processed annually in the USSR). The stringent environmental regulations, coupled with the tendency to increase the use of coal are the reasons for developing different concepts for clean coal utilization. In this paper, the potential efficiency and environmental performance of different clean coal production cycles are considered, including technologies for coal clean-up at the pre-combustion stage, advanced clean combustion methods and flue gas cleaning systems. Integrated systems, such as combined gas-steam cycle and the pressurized fluidized bed boiler combined cycle, are also discussed. The Soviet National R and D program is studying new methods for coal utilization with high environmental performance. In this context, some basic research activities in the field of clean coal technology in the USSR are considered. Development of an efficient vortex combustor, a pressurized fluidized bed gasifier, advanced gas cleaning methods based on E-beam irradiation and plasma discharge, as well as new catalytic system, are are presented. In addition, implementation of technological innovations for retrofitting and re powering of existing power plants is discussed. (author)

  4. Cleaning protocol for a FO membrane fouled in wastewater reuse

    KAUST Repository

    Valladares Linares, Rodrigo; Li, Zhenyu; Yangali-Quintanilla, Victor; Li, Qingyu; Amy, Gary L.

    2013-01-01

    Forward osmosis (FO) is an emerging technology which can be applied in water reuse applications. Osmosis is a natural process that involves less energy consumption than reverse osmosis (RO), and therefore can be applied as a dilution process before low-pressure RO; it is expected to compete favourably against current advanced water reuse technologies that use microfiltration/ultrafiltration and RO. The focus of this research was to assess the efficiency of different cleaning procedures to remove fouling from the surface of a FO membrane during the operation of a submerged system working in FO-mode (active layer (AL) facing feed solution) intended for secondary wastewater effluent (SWWE) recovery, using seawater as draw solution (DS), which will be diluted and can further be fed to a low-pressure RO unit to produce fresh water. Natural organic matter (NOM) fouling was expected to affect the AL, while for the support layer (SL), transparent exopolymer particles (TEP) were used as indicators of fouling due to their stickiness and propensity to enhance the attachment of other foulants in seawater on the membrane surface. The composition of the NOM fouling layer was determined after proper characterisation with a liquid chromatograph coupled with organic carbon detection (LC-OCD), showing biopolymers and protein-like substances as the main constituents. NOM fouling showed high hydraulic reversibility after a 25% flux decline was observed, up to 89.5% when in situ air scouring for 15 min was used as a cleaning technique. Chemical cleaning with a mixture of Alconox, an industrial detergent containing phosphates, and sodium EDTA showed to increase the reversibility (93.6%). Osmotic backwash using a 4% NaCl solution and DI water proved to be ineffective to recover flux due to the salt diffusion phenomena occurring at the AL. Part of the flux that could not be recovered is attributable to TEP fouling on the SL, which forms clusters clearly identifiable with an optical

  5. Cleaning protocol for a FO membrane fouled in wastewater reuse

    KAUST Repository

    Valladares Linares, Rodrigo

    2013-05-30

    Forward osmosis (FO) is an emerging technology which can be applied in water reuse applications. Osmosis is a natural process that involves less energy consumption than reverse osmosis (RO), and therefore can be applied as a dilution process before low-pressure RO; it is expected to compete favourably against current advanced water reuse technologies that use microfiltration/ultrafiltration and RO. The focus of this research was to assess the efficiency of different cleaning procedures to remove fouling from the surface of a FO membrane during the operation of a submerged system working in FO-mode (active layer (AL) facing feed solution) intended for secondary wastewater effluent (SWWE) recovery, using seawater as draw solution (DS), which will be diluted and can further be fed to a low-pressure RO unit to produce fresh water. Natural organic matter (NOM) fouling was expected to affect the AL, while for the support layer (SL), transparent exopolymer particles (TEP) were used as indicators of fouling due to their stickiness and propensity to enhance the attachment of other foulants in seawater on the membrane surface. The composition of the NOM fouling layer was determined after proper characterisation with a liquid chromatograph coupled with organic carbon detection (LC-OCD), showing biopolymers and protein-like substances as the main constituents. NOM fouling showed high hydraulic reversibility after a 25% flux decline was observed, up to 89.5% when in situ air scouring for 15 min was used as a cleaning technique. Chemical cleaning with a mixture of Alconox, an industrial detergent containing phosphates, and sodium EDTA showed to increase the reversibility (93.6%). Osmotic backwash using a 4% NaCl solution and DI water proved to be ineffective to recover flux due to the salt diffusion phenomena occurring at the AL. Part of the flux that could not be recovered is attributable to TEP fouling on the SL, which forms clusters clearly identifiable with an optical

  6. Chemical kinetics of flue gas cleaning by electron beam

    International Nuclear Information System (INIS)

    Maetzing, H.

    1989-02-01

    By electron beam treatment of flue gases, NO x and SO 2 are converted to nitric and sulfuric acids simultaneously. Upon ammonia addition, the corresponding salts are collected in solid state and can be sold as fertilizer. Both homogeneous gas phase reactions and physico-chemical aerosol dynamics are involved in product formation. These processes have been analyzed by model calculations. In part 1, the present report summarizes the model results and gives an account of the theoretical understanding of the EBDS process and its performance characteristics. Part 2 of this report gives a complete listing of the reactions used in the AGATE code. (orig.) [de

  7. Measuring cavitation and its cleaning effect

    NARCIS (Netherlands)

    Verhaagen, B.; Fernandez Rivas, David

    2016-01-01

    The advantages and limitations of techniques for measuring the presence and amount of cavitation, and for quantifying the removal of contaminants, are provided. After reviewing chemical, physical, and biological studies, a universal cause for the cleaning effects of bubbles cannot yet be concluded.

  8. Washing away your sins in the brain: physical cleaning and priming of cleaning recruit different brain networks after moral threat.

    Science.gov (United States)

    Tang, Honghong; Lu, Xiaping; Su, Rui; Liang, Zilu; Mai, Xiaoqin; Liu, Chao

    2017-07-01

    The association between moral purity and physical cleanliness has been widely discussed recently. Studies found that moral threat initiates the need of physical cleanliness, but actual physical cleaning and priming of cleaning have inconsistent effects on subsequent attitudes and behaviors. Here, we used resting-state functional magnetic resonance imaging to explore the underlying neural mechanism of actual physical cleaning and priming of cleaning. After recalling moral transgression with strong feelings of guilt and shame, participants either actually cleaned their faces with a wipe or were primed with cleanliness through viewing its pictures. Results showed that actual physical cleaning reduced the spontaneous brain activities in the right insula and MPFC, regions that involved in embodied moral emotion processing, while priming of cleaning decreased activities in the right superior frontal gyrus and middle frontal gyrus, regions that participated in executive control processing. Additionally, actual physical cleaning also changed functional connectivity between insula/MPFC and emotion related regions, whereas priming of cleaning modified connectivity within both moral and sensorimotor areas. These findings revealed that actual physical cleaning and priming of cleaning led to changes in different brain regions and networks, providing neural evidence for the inconsistent effects of cleanliness on subsequent attitudes and behaviors. © The Author (2017). Published by Oxford University Press.

  9. Critical flux and chemical cleaning-in-place during the long-term operation of a pilot-scale submerged membrane bioreactor for municipal wastewater treatment

    KAUST Repository

    Wei, Chunhai

    2011-01-01

    The critical flux and chemical cleaning-in-place (CIP) in a long-term operation of a pilot-scale submerged membrane bioreactor for municipal wastewater treatment were investigated. Steady filtration under high flux (30 L/(m2 h)) was successfully achieved due to effective membrane fouling control by sub-critical flux operation and chemical CIP with sodium hypochlorite (NaClO) in both trans-membrane pressure (TMP) controlling mode (cleaning with high concentration NaClO of 2000-3000 mg/L in terms of effective chorine was performed when TMP rose to 15 kPa) and time controlling mode (cleanings were performed weekly and monthly respectively with low concentration NaClO (500-1000 mg/L) and high concentration NaClO (3000 mg/L)). Microscopic analysis on membrane fibers before and after high concentration NaClO was also conducted. Images of scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that NaClO CIP could effectively remove gel layer, the dominant fouling under sub-critical flux operation. Porosity measurements indicated that NaClO CIP could partially remove pore blockage fouling. The analyses from fourier transform infrared spectrometry (FTIR) with attenuated total reflectance accessory (ATR) and energy dispersive spectrometer (EDS) demonstrated that protein-like macromolecular organics and inorganics were the important components of the fouling layer. The analysis of effluent quality before and after NaClO CIP showed no obvious effect on effluent quality. © 2010 Elsevier Ltd.

  10. Manufacturing of NAA laboratory clean room

    International Nuclear Information System (INIS)

    Suwoto; Hasibuan, Djaruddin

    2001-01-01

    The ''NAA laboratory clean room'' has been built in the Reactor Serba Guna G.A. Siwabessy building. The erection of ''AAN laboratory clean room'' doing by started of preparation of the ''manufacturing procedure'' refer to ''Design and manufacturing neutron activation analysis clean room laboratory''. Manufacturing process and erection doing refer to procedures makes. By providing of the ''AAN laboratory clean room'' can be cocluded that the research activity and the user sevises in P2TRR well meet to be done

  11. Cleaning must be well planned; Rengjoeringsopplegget maa planlegges

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Both detergents and water may damage painted and varnished surfaces in the long run. It is therefore important to choose the right cleaning method once the rooms are put to use. It is essential that a cleaning method be found that does not require great quantities of chemicals. Professional cleaning implies that a program is used that describes in detail the cleaning operation in each room. Materials used in walls often do not tolerate much moisture. If such components are cleaned by means of too much water to which is added detergents, they may swell. These walls are exposed above all the first time they are cleaned because those doing the cleaning are not aware of the situation. Some of the detergents in current use contain hazardous components. It is very important to know the individual detergent's contents of volatile components as these may cause damage. Some detergents may lead to deterioration of the surface if incorrectly used. Some contain perfume or dyes that may develop allergies. Thus, detergents must be selected with due consideration of both the subject and the personnel. Declaration and user instruction is necessary.

  12. Researches in increase of efficiency of electrokinetic process of ground cleaning from radionuclides

    International Nuclear Information System (INIS)

    Prozorov, L.B.; Shcheglov, M.Y.; Nikolaevsky, V.B.; Tkachenko, A.V.

    2003-01-01

    Potentially perspective method of decontamination of ground is electrokinetic method, which basic advantage consists in an opportunity of its application for clearing ground with low filtering by ability directly on a place of local contaminated (in situ). Thus moving the large volumes of the contaminated ground is excluded. Base of this method is the processes of electromigration and electro-osmotic, proceeding in a contaminated ground lay at imposing an electrical field of a constant current. Electrokinetic method of cleaning of ground from radionuclides provides their transfer in water-soluble, mobile form, carry as positive or negative ions under influence of an electrical field into electrode chambers with their subsequent recycling.Electrokinetic method in practice can be realized as follows: in the contaminated ground establish special electrode devices, fill their electrolyte and connect to a source of a constant current. Formed in the anode device as a result of electrochemical decomposition of water the ions of hydrogen under action of an electrical field move to the cathode, thus cooperate with a ground and superside cations of radioactive elements. Desorbed cations of contaminate act in catholyte, which periodically or continuously is exposed to clearing, for example, on sorption column. Last years the experts MosNPO Radon carry out complex researches directed on development of electrokinetic technology of cleaning ground from radionuclides and heavy metals. To the present time laboratory and bench tests of electrokinetic method are carried out. The basic attention at study of process of cleaning was given to objects contaminated Cs-137, most difficult recovery an element, which is strongly fixed by clay minerals and can enter into crystal structure. (authors)

  13. CLEAN CHEMICAL SYNTHESIS IN WATER

    Science.gov (United States)

    Newer green chemistry approach to accomplish chemical synthesis in water is summarized. Recent global developments pertaining to C-C bond forming reactions using metallic reagents and direct use of the renewable materials such as carbohydrates without derivatization are described...

  14. Evaporator Cleaning Studies

    International Nuclear Information System (INIS)

    Wilmarth, W.R.

    1999-01-01

    Operation of the 242-16H High Level Waste Evaporator proves crucial to liquid waste management in the H-Area Tank Farm. Recent operational history of the Evaporator showed significant solid formation in secondary lines and in the evaporator pot. Additional samples remain necessary to ensure material identity in the evaporator pot. Analysis of these future samples will provide actinide partitioning information and dissolution characteristics of the solid material from the pot to ensure safe chemical cleaning

  15. Hydrogen production from natural gas using an iron-based chemical looping technology: Thermodynamic simulations and process system analysis

    International Nuclear Information System (INIS)

    Kathe, Mandar V.; Empfield, Abbey; Na, Jing; Blair, Elena; Fan, Liang-Shih

    2016-01-01

    Highlights: • Design of iron-based chemical looping process using moving bed for H_2 from CH_4. • Auto-thermal operation design using thermodynamic rationale for 90% carbon capture. • Cold gas efficiency: 5% points higher than Steam Methane Reforming baseline case. • Net thermal efficiency: 6% points higher than Steam Methane Reforming baseline case. • Sensitivity analysis: Energy recovery scheme, operating pressure, no carbon capture. - Abstract: Hydrogen (H_2) is a secondary fuel derived from natural gas. Currently, H_2 serves as an important component in refining operations, fertilizer production, and is experiencing increased utilization in the transportation industry as a clean combustion fuel. In recent years, industry and academia have focused on developing technology that reduces carbon emissions. As a result, there has been an increase in the technological developments for producing H_2 from natural gas. These technologies aim to minimize the cost increment associated with clean energy production. The natural gas processing chemical looping technology, developed at The Ohio State University (OSU), employs an iron-based oxygen carrier and a novel gas–solid counter-current moving bed reactor for H_2 production. Specifically, this study examines the theoretical thermodynamic limits for full conversion of natural gas through iron-based oxygen carrier reactions with methane (CH_4), by utilizing simulations generated with ASPEN modeling software. This study initially investigates the reducer and the oxidizer thermodynamic phase diagrams then derives an optimal auto-thermal operating condition for the complete loop simulation. This complete loop simulation is initially normalized for analysis on the basis of one mole of carbon input from natural gas. The H_2 production rate is then scaled to match that of the baseline study, using a full-scale ASPEN simulation for computing cooling loads, water requirements and net parasitic energy consumption. The

  16. The Solubility of Ozone in Deionized Water and its Cleaning Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Han, J.H.; Park, J.G. [Hanyang University, Seoul (Korea, Republic of); Kwak, Y.S. [Hanyang Technology Co., Ltd., Ansan (Korea, Republic of)

    1998-06-01

    The purpose of this study was to investigate the behavior of ozone in DI water and the reaction with wafers during the semiconductor wet cleaning process. The solubility of ozone in DI water was not only dependent on the temperature but also directly proportional to the input concentration of ozone. The lower the initial ozone concentration and the temperature, the longer the half-life time of ozone. The reaction order of ozone in DI water was calculated to be around 1.5. The redox potential reached a saturation value in 5min and slightly increased as the input ozone concentrations increased. The completely hydrophilic surface was created in 1min when HF etched silicon wafer was cleaned in ozonized DI water containing higher ozone concentrations than 2ppm. Spectroscopic ellipsometry measurements showed that the chemical oxide formed by ozonized DI water was measured to be thicker than that by piranha solution. The wafers contaminated with a non-ionic surfactant were more effectively cleaned in ozonized DI water than in piranha and ozonized piranha solutions. (author). 19 refs., 11 figs., 1 tab.

  17. Measurement of the Residual Sodium and Reaction Compounds on a Cleaned Cold Trap

    International Nuclear Information System (INIS)

    Kim, Byung Ho; Jeong, Ji Young; Kim, Jong Man; Choi, Byung Hae; Nam, Ho Yun Nam

    2006-01-01

    The purpose of a cleaning process is to remove the residual sodium adhering to the component walls once it has been properly drained. It is necessary to clean and decontaminate a component, especially the large components of the primary coolant system; such as the intermediate heat exchangers and the primary pump. Improper and inadequate cleaning has in a number of cases resulted in problems in the storage, handling, and reuse of components. Inadequate and incomplete removal of sodium results in residues which may contain metallic sodium and alkaline compounds such as sodium hydroxide, sodium oxide, sodium carbonate, and various types of alcoholates. Reinsertion of components containing these compounds into a high-temperature sodium system can result in either a intergranular penetration characteristic of a high-oxygen sodium or an accelerated corrosion due to oxygen. Cleaning methods are needed that will avoid a deleterious local overheating, material surface degradation or deposits, a chemical, physical, or mechanical damage, and external effects. It is important to determine the levels of residual sodium that can be accepted so that those deleterious effects will not negate the reuse of the component. The purpose of this paper is to measure the amount of the sodium and the reaction compounds remaining on a component after a cleaning and prepare acceptable criteria for the reuse of components which have been subjected to a sodium cleaning

  18. Hierarchical surfaces for enhanced self-cleaning applications

    International Nuclear Information System (INIS)

    Fernández, Ariadna; Francone, Achille; Sotomayor Torres, Clivia M; Kehagias, Nikolaos; Thamdrup, Lasse H; Johansson, Alicia; Bilenberg, Brian; Nielsen, Theodor; Guttmann, Markus

    2017-01-01

    In this study we present a flexible and adaptable fabrication method to create complex hierarchical structures over inherently hydrophobic resist materials. We have tested these surfaces for their superhydrophobic behaviour and successfully verified their self-cleaning properties. The followed approach allow us to design and produce superhydrophobic surfaces in a reproducible manner. We have analysed different combination of hierarchical micro-nanostructures for their application to self-cleaning surfaces. A static contact angle value of 170° with a hysteresis of 4° was achieved without the need of any additional chemical treatment on the fabricated hierarchical structures. Dynamic effects were analysed on these surfaces, obtaining a remarkable self-cleaning effect as well as a good robustness over impacting droplets. (paper)

  19. Use of direct washing of chemical dispense nozzle for defect control

    Science.gov (United States)

    Linnane, Michael; Mack, George; Longstaff, Christopher; Winter, Thomas

    2006-03-01

    Demands for continued defect reduction in 300mm IC manufacturing are driving process engineers to examine all aspects of the chemical apply process for improvement. Historically, the defect contribution from photoresist apply nozzles has been minimized through a carefully controlled process of "dummy dispenses" to keep the photoresist in the tip "fresh" and remove any solidified material, a preventive maintenance regime involving periodic cleaning or replacing of the nozzles, and reliance on a pool of solvent within the nozzle storage block to keep the photoresist from solidifying at the nozzle tip. The industry standard has worked well for the most part but has limitations in terms of cost effectiveness and absolute defect elimination. In this study, we investigate the direct washing of the chemical apply nozzle to reduce defects seen on the coated wafer. Data is presented on how the direct washing of the chemical dispense nozzle can be used to reduce coating related defects, reduce material costs from the reduction of "dummy dispense", and can reduce equipment downtime related to nozzle cleaning or replacement.

  20. Cleaning of aluminum after machining with coolants

    International Nuclear Information System (INIS)

    Roop, B.

    1992-01-01

    An x-ray photoemission spectroscopic study was undertaken to compare the cleaning of the Advanced Photon Source (APS) aluminum extrusion storage ring vacuum chambers after machining with and without water soluble coolants. While there was significant contamination left by the coolants, the cleaning process was capable of removing the residue. The variation of the surface and near surface composition of samples machined either dry or with coolants was negligible after cleaning. The use of such coolants in the machining process is therefore recommended

  1. [Comprehension of hazard pictograms of chemical products among cleaning workers].

    Science.gov (United States)

    Martí Fernández, Francesc; van der Haar, Rudolf; López López, Juan Carlos; Portell, Mariona; Torner Solé, Anna

    2015-01-01

    To assess the comprehension among cleaning workers of the hazard pictograms as defined by the Globally Harmonized System (GHS) of the United Nations, concerning the classification, labeling and packaging of substances and mixtures. A sample of 118 workers was surveyed on their perception of the GHS hazard pictograms. Comprehensibility was measured by the percentage of correct answers and the degree to which they reflected International Organization for Standardization and American National Standards Institute standards for minimum level of comprehension. The influence of different variables to predict comprehension capacity was assessed using a logistic regression model. Three groups of pictograms could be distinguished which were statistically differentiated by their comprehensibility. Pictograms reflecting "acute toxicity" and "flammable", were described correctly by 94% and 95% of the surveyed population, respectively. For pictograms reflecting "systemic toxicity", "corrosive", "warning", "environment" and "explosive" the frequency of correct answers ranged from 48% to 64%, whereas those for pictograms "oxidizing" and "compressed gas" were interpreted correctly by only 7% of respondents. Prognostic factors for poor comprehension included: not being familiar with the pictograms, not having received training on safe use of chemical products, being an immigrant and being 54 years of age or older. Only two pictograms exceeded minimum standards for comprehension. Training, a tool proven to be effective to improve the correct interpretation of danger symbols, should be encouraged, especially in those groups with greater comprehension difficulties. Copyright belongs to the Societat Catalana de Salut Laboral.

  2. Clean graphene electrodes on organic thin-film devices via orthogonal fluorinated chemistry.

    Science.gov (United States)

    Beck, Jonathan H; Barton, Robert A; Cox, Marshall P; Alexandrou, Konstantinos; Petrone, Nicholas; Olivieri, Giorgia; Yang, Shyuan; Hone, James; Kymissis, Ioannis

    2015-04-08

    Graphene is a promising flexible, highly transparent, and elementally abundant electrode for organic electronics. Typical methods utilized to transfer large-area films of graphene synthesized by chemical vapor deposition on metal catalysts are not compatible with organic thin-films, limiting the integration of graphene into organic optoelectronic devices. This article describes a graphene transfer process onto chemically sensitive organic semiconductor thin-films. The process incorporates an elastomeric stamp with a fluorinated polymer release layer that can be removed, post-transfer, via a fluorinated solvent; neither fluorinated material adversely affects the organic semiconductor materials. We used Raman spectroscopy, atomic force microscopy, and scanning electron microscopy to show that chemical vapor deposition graphene can be successfully transferred without inducing defects in the graphene film. To demonstrate our transfer method's compatibility with organic semiconductors, we fabricate three classes of organic thin-film devices: graphene field effect transistors without additional cleaning processes, transparent organic light-emitting diodes, and transparent small-molecule organic photovoltaic devices. These experiments demonstrate the potential of hybrid graphene/organic devices in which graphene is deposited directly onto underlying organic thin-film structures.

  3. An experimental evaluation on air purification performance of Clean-Air Heat Pump (CAHP) air cleaner

    DEFF Research Database (Denmark)

    Sheng, Ying; Fang, Lei; Sun, Yuexia

    2018-01-01

    was 96.8%, which indicated that the most of gaseous pollutants were not accumulated in the CAHP. The regeneration temperature for the wheel could affect the air purification performance of CAHP. At 70 °C of regeneration temperature, the air-cleaning efficiency reached 96.7%. Up to 70% of the outdoor air......The escalation of energy consumption in buildings and heightened concerns about acceptable indoor air quality stimulate interest in the usage of air cleaner as an adjunct for indoor environmental conditioning. A regenerative desiccant wheel integrated into a ventilation system termed Clean-Air Heat...... Pump (CAHP) can improve the air quality during the process of dehumidification without using additional energy. An experimental study in a field lab was performed to investigate the air cleaning performance of CAHP. Photoacoustic gas analyzer-INNOVA was used to characterize chemical removal of indoor...

  4. Chemical process and plant design bibliography 1959-1989

    International Nuclear Information System (INIS)

    Ray, M.S.

    1991-01-01

    This book is concerned specifically with chemical process in formation and plant equipment design data. It is a source for chemical engineers, students and academics involved in process and design evaluation. Over 500 chemical categories are included, from Acetaldehyde to zirconium Dioxide, with cross-referencing within the book to appropriate associated chemicals

  5. ENVIRONMENTAL TECHNOLOGY INITIATIVE: CHEMICAL-FREE CLEANING OF SEMICONDUCTORS BY THE RADIANCE PROCESS

    Science.gov (United States)

    The Radiance Process is a patented dry process for removing contaminants from surfaces. It uses light, usually from a pulsed laser and a gas inert to the surface, to entrain released contaminants. The focus of this effort is to assess the applicability of the Radiance Process t...

  6. NOM and TEP fouling of a forward osmosis (FO) membrane: Foulant identification and cleaning

    KAUST Repository

    Valladares Linares, Rodrigo

    2012-12-01

    The study of forward osmosis (FO) membranes has increased due to the already demonstrated advantages compared to high-energy membrane processes such as reverse osmosis (RO). This research focuses on characterization of the natural organic matter (NOM) fraction causing fouling on the active layer (AL) of a FO membrane in a novel plate and frame module configuration, facing secondary wastewater effluent as a feed solution (FS) and seawater used as a draw solution (DS). In addition, transparent exopolymer particles (TEP) were observed on the support layer (SL) of the membrane in contact with the DS. The NOM fouling layer, after characterizing the water samples and membranes used, was found to be composed of biopolymers and protein-like substances, which adversely affect the flux of water through the FO membrane. However, NOM fouling showed high reversibility, up to 90% when air scouring for 15. min is used as a cleaning technique. The irreversible fouling in this work was found to be 8.2% after chemical cleaning. On the support layer of the membrane, TEP formed clusters clearly identifiable with an optical microscope and a TEP-specific dye. Chemical cleaning with 1% NaOCl for 10. min proved to be the most effective method to remove TEP. © 2012.

  7. NOM and TEP fouling of a forward osmosis (FO) membrane: Foulant identification and cleaning

    KAUST Repository

    Valladares Linares, Rodrigo; Yangali-Quintanilla, Victor; Li, Zhenyu; Amy, Gary L.

    2012-01-01

    The study of forward osmosis (FO) membranes has increased due to the already demonstrated advantages compared to high-energy membrane processes such as reverse osmosis (RO). This research focuses on characterization of the natural organic matter (NOM) fraction causing fouling on the active layer (AL) of a FO membrane in a novel plate and frame module configuration, facing secondary wastewater effluent as a feed solution (FS) and seawater used as a draw solution (DS). In addition, transparent exopolymer particles (TEP) were observed on the support layer (SL) of the membrane in contact with the DS. The NOM fouling layer, after characterizing the water samples and membranes used, was found to be composed of biopolymers and protein-like substances, which adversely affect the flux of water through the FO membrane. However, NOM fouling showed high reversibility, up to 90% when air scouring for 15. min is used as a cleaning technique. The irreversible fouling in this work was found to be 8.2% after chemical cleaning. On the support layer of the membrane, TEP formed clusters clearly identifiable with an optical microscope and a TEP-specific dye. Chemical cleaning with 1% NaOCl for 10. min proved to be the most effective method to remove TEP. © 2012.

  8. Rudimentary Cleaning Compared to Level 300A

    Science.gov (United States)

    Arpin, Christina Y. Pina; Stoltzfus, Joel

    2012-01-01

    A study was done to characterize the cleanliness level achievable when using a rudimentary cleaning process, and results were compared to JPR 5322.1G Level 300A. While it is not ideal to clean in a shop environment, some situations (e.g., field combat operations) require oxygen system hardware to be maintained and cleaned to prevent a fire hazard, even though it cannot be sent back to a precision cleaning facility. This study measured the effectiveness of basic shop cleaning. Initially, three items representing parts of an oxygen system were contaminated: a metal plate, valve body, and metal oxygen bottle. The contaminants chosen were those most likely to be introduced to the system during normal use: oil, lubricant, metal shavings/powder, sand, fingerprints, tape, lip balm, and hand lotion. The cleaning process used hot water, soap, various brushes, gaseous nitrogen, water nozzle, plastic trays, scouring pads, and a controlled shop environment. Test subjects were classified into three groups: technical professionals having an appreciation for oxygen hazards; professional precision cleaners; and a group with no previous professional knowledge of oxygen or precision cleaning. Three test subjects were in each group, and each was provided with standard cleaning equipment, a cleaning procedure, and one of each of the three test items to clean. The results indicated that the achievable cleanliness level was independent of the technical knowledge or proficiency of the personnel cleaning the items. Results also showed that achieving a Level 300 particle count was more difficult than achieving a Level A nonvolatile residue amount.

  9. Plasma cleaning of ITER first mirrors

    Science.gov (United States)

    Moser, L.; Marot, L.; Steiner, R.; Reichle, R.; Leipold, F.; Vorpahl, C.; Le Guern, F.; Walach, U.; Alberti, S.; Furno, I.; Yan, R.; Peng, J.; Ben Yaala, M.; Meyer, E.

    2017-12-01

    Nuclear fusion is an extremely attractive option for future generations to compete with the strong increase in energy consumption. Proper control of the fusion plasma is mandatory to reach the ambitious objectives set while preserving the machine’s integrity, which requests a large number of plasma diagnostic systems. Due to the large neutron flux expected in the International Thermonuclear Experimental Reactor (ITER), regular windows or fibre optics are unusable and were replaced by so-called metallic first mirrors (FMs) embedded in the neutron shielding, forming an optical labyrinth. Materials eroded from the first wall reactor through physical or chemical sputtering will migrate and will be deposited onto mirrors. Mirrors subject to net deposition will suffer from reflectivity losses due to the deposition of impurities. Cleaning systems of metallic FMs are required in more than 20 optical diagnostic systems in ITER. Plasma cleaning using radio frequency (RF) generated plasmas is currently being considered the most promising in situ cleaning technique. An update of recent results obtained with this technique will be presented. These include the demonstration of cleaning of several deposit types (beryllium, tungsten and beryllium proxy, i.e. aluminium) at 13.56 or 60 MHz as well as large scale cleaning (mirror size: 200 × 300 mm2). Tests under a strong magnetic field up to 3.5 T in laboratory and first experiments of RF plasma cleaning in EAST tokamak will also be discussed. A specific focus will be given on repetitive cleaning experiments performed on several FM material candidates.

  10. Clean Technology Evaluation & Workforce Development Program

    Energy Technology Data Exchange (ETDEWEB)

    Patricia Glaza

    2012-12-01

    The overall objective of the Clean Technology Evaluation portion of the award was to design a process to speed up the identification of new clean energy technologies and match organizations to testing and early adoption partners. The project was successful in identifying new technologies targeted to utilities and utility technology integrators, in developing a process to review and rank the new technologies, and in facilitating new partnerships for technology testing and adoption. The purpose of the Workforce Development portion of the award was to create an education outreach program for middle & high-school students focused on clean technology science and engineering. While originally targeting San Diego, California and Cambridge, Massachusetts, the scope of the program was expanded to include a major clean technology speaking series and expo as part of the USA Science & Engineering Festival on the National Mall in Washington, D.C.

  11. Correlating Cleaning Thoroughness with Effectiveness and Briefly Intervening to Affect Cleaning Outcomes: How Clean Is Cleaned?

    Directory of Open Access Journals (Sweden)

    Robert Clifford

    Full Text Available The most efficient approach to monitoring and improving cleaning outcomes remains unresolved. We sought to extend the findings of a previous study by determining whether cleaning thoroughness (dye removal correlates with cleaning efficacy (absence of molecular or cultivable biomaterial and whether one brief educational intervention improves cleaning outcomes.Before-after trial.Newly built community hospital.90 minute training refresher with surface-specific performance results.Dye removal, measured by fluorescence, and biomaterial removal and acquisition, measured with culture and culture-independent PCR-based assays, were clandestinely assessed for eight consecutive months. At this midpoint, results were presented to the cleaning staff (intervention and assessments continued for another eight consecutive months.1273 surfaces were sampled before and after terminal room cleaning. In the short-term, dye removal increased from 40.3% to 50.0% (not significant. For the entire study period, dye removal also improved but not significantly. After the intervention, the number of rooms testing positive for specific pathogenic species by culturing decreased from 55.6% to 36.6% (not significant, and those testing positive by PCR fell from 80.6% to 53.7% (P = 0.016. For nonspecific biomaterial on surfaces: a removal of cultivable Gram-negatives (GN trended toward improvement (P = 0.056; b removal of any cultivable growth was unchanged but acquisition (detection of biomaterial on post-cleaned surfaces that were contaminant-free before cleaning worsened (P = 0.017; c removal of PCR-based detection of bacterial DNA improved (P = 0.046, but acquisition worsened (P = 0.003; d cleaning thoroughness and efficacy were not correlated.At this facility, a minor intervention or minimally more aggressive cleaning may reduce pathogen-specific contamination, but not without unintended consequences.

  12. Physical-chemical hydrodynamics of the processes of sorption-membrane technology of LRW treatment

    International Nuclear Information System (INIS)

    Alexander D Efanov; Pyotr N Martynov; Yuri D Boltoev; Ivan V Yagodkin; Nataliya G Bogdanovich; Sergey S Skvortsov; Alexander R Sokolovsky; Elena V Ignatova; Gennady V Grigoriev; Vitaly V Grigorov

    2005-01-01

    tripolite and clinoptilolite of radionuclides 137 Cs and 90 Sr and other from liquid radioactive waste; -the parameter values of tripolite and clinoptilolite coagulation and sedimentation processes under the LRW free convection conditions; - the specific features of the spatial distribution of the pressure micro-fluctuations of LRW flow being passed through the porous system 'nano-structured membrane substrate' in the filtration conditions and in the course of the membrane surface cleaning from cake. The above investigation results have been obtained on a model liquid waste sorption-membrane cleaning test facility. The test facility is unique in that its tanks are manufactured of transparent polycarbonate and do not yield to stain steel tanks in strength. This means that the physical-chemical hydrodynamics of the all processes of the sorption-membrane technology is visualized and can be represented in the evolution of the processes including abnormal conditions. (authors)

  13. Hydrodynamic design of an underwater hull cleaning robot and its evaluation

    Directory of Open Access Journals (Sweden)

    Man Hyung Lee

    2012-12-01

    Full Text Available An underwater hull cleaning robot can be a desirable choice for the cleaning of large ships. It can make the cleaning process safe and economical. This paper presents a hydrodynamic design of an underwater cleaning robot and its evaluation for an underwater ship hull cleaning robot. The hydrodynamic design process of the robot body is described in detail. Optimal body design process with compromises among conflicting design requirements is given. Experimental results on the hydrodynamic performance of the robot are given.

  14. Electrospun Superhydrophobic Self-Cleaning Materials

    Science.gov (United States)

    Zhao, Yong; Wang, Nü

    In this chapter, we introduce the wettability of electrospinning products. Especially, we concentrate on the fabrication, characteristics, and applications of the electrospun self-cleaning materials. Self-cleaning materials are typical nature-inspired artificial materials learning from such as lotus leaf and many other plants or animals. Self-cleaning materials usually rely on a superhydrophobic surface, which should be of low surface free energy as well as large surface roughness. Electrospinning method is such a method that could facilely shape various hydrophobic polymers into ultrathin fibers with tunable surface microstructures. It means the electrospun products are of very large specific area, which satisfy the two basic conditions in preparing superhydrophobic surfaces. Therefore, in the last decade, scientists put forward a good few of elegant approaches to fabricate superhydrophobic materials by electrospinning. These methods can be generally classified into two routes. One is a direct route that creates superhydrophobic electrospun films from hydrophobic materials. Another is an indirect route that decorates electrospun nanofibers (no matter hydrophobic or hydrophilic) with hydrophobic chemicals. We first introduce some representative works on the fabrication of superhydrophobic self-cleaning materials by electrospinning method. Then we show some applications of these superhydrophobic materials. Finally, we give a brief personal perspective on this area.

  15. Laser cleaning on Roman coins

    Science.gov (United States)

    Drakaki, E.; Karydas, A. G.; Klinkenberg, B.; Kokkoris, M.; Serafetinides, A. A.; Stavrou, E.; Vlastou, R.; Zarkadas, C.

    Ancient metal objects react with moisture and environmental chemicals to form various corrosion products. Because of the unique character and high value of such objects, any cleaning procedure should guarantee minimum destructiveness. The most common treatment used is mechanical stripping, in which it is difficult to avoid surface damage when employed. Lasers are currently being tested for a wide range of conservation applications. Since they are highly controllable and can be selectively applied, lasers can be used to achieve more effective and safer cleaning of archaeological artifacts and protect their surface details. The basic criterion that motivated us to use lasers to clean Roman coins was the requirement of pulsed emission, in order to minimize heat-induced damages. In fact, the laser interaction with the coins has to be short enough, to produce a fast removal of the encrustation, avoiding heat conduction into the substrate. The cleaning effects of three lasers operating at different wavelengths, namely a TEA CO2 laser emitting at 10.6 μm, an Er:YAG laser at 2.94 μm, and a 2ω-Nd:YAG laser at 532 nm have been compared on corroded Romans coins and various atomic and nuclear techniques have also been applied to evaluate the efficiency of the applied procedure.

  16. Textiles and clothing sustainability sustainable textile chemical processes

    CERN Document Server

    2017-01-01

    This book highlights the challenges in sustainable wet processing of textiles, natural dyes, enzymatic textiles and sustainable textile finishes. Textile industry is known for its chemical processing issues and many NGO’s are behind the textile sector to streamline its chemical processing, which is the black face of clothing and fashion sector. Sustainable textile chemical processes are crucial for attaining sustainability in the clothing sector. Seven comprehensive chapters are aimed to highlight these issues in the book.

  17. Comparison of Fenton process and adsorption method for treatment of industrial container and drum cleaning industry wastewater.

    Science.gov (United States)

    Güneş, Elçin; Çifçi, Deniz İzlen; Çelik, Suna Özden

    2018-04-01

    The present study aims to explore the characterization of industrial container and drum cleaning (ICDC) industry wastewater and treatment alternatives of this wastewater using Fenton and adsorption processes. Wastewater derived from ICDC industry is usually treated by chemical coagulation and biological treatment in Turkey and then discharged in a centralized wastewater treatment facility. It is required that the wastewater COD is below 1500 mg/L to treat in a centralized wastewater treatment facility. The wastewater samples were characterized for parameters of pH, conductivity, COD, BOD 5 , TSS, NH 3 -N, TN, TOC, TP, Cd, Cr, Cu, Fe, Ni, Pb, Zn, and Hg. Initial COD values were in the range of 11,300-14,200 mg/L. The optimum conditions for Fenton treatment were 35-40 g/L for H 2 O 2 , 2-5 g/L for Fe 2+ , and 13-36 for H 2 O 2 /Fe 2+ molar ratio. The optimum conditions of PAC doses and contact times in adsorption studies were 20-30 g/L and 5-12 h, respectively. Removal efficiencies of characterized parameters for the three samples were compared for both Fenton and adsorption processes under optimum conditions. The results suggest that these wastewaters are suitable for discharge to a centralized wastewater treatment plant.

  18. Development of Chemical and Mechanical Cleaning Procedures for Genesis Solar Wind Samples

    Science.gov (United States)

    Schmeling, M.; Jurewicz, A. J. G.; Gonzalez, C.; Allums, K. K.; Allton, J. H.

    2018-01-01

    The Genesis mission was the only mission returning pristine solar material to Earth since the Apollo program. Unfortunately, the return of the spacecraft on September 8, 2004 resulted in a crash landing shattering the solar wind collectors into smaller fragments and exposing them to desert soil and other debris. Thorough surface cleaning is required for almost all fragments to allow for subsequent analysis of solar wind material embedded within. However, each collector fragment calls for an individual cleaning approach, as contamination not only varies by collector material but also by sample itself.

  19. Chemical process safety management within the Department of Energy

    International Nuclear Information System (INIS)

    Piatt, J.A.

    1995-07-01

    Although the Department of Energy (DOE) is not well known for its chemical processing activities, the DOE does have a variety of chemical processes covered under OSHA's Rule for Process Safety Management of Highly Hazardous Chemicals (the PSM Standard). DOE, like industry, is obligated to comply with the PSM Standard. The shift in the mission of DOE away from defense programs toward environmental restoration and waste management has affected these newly forming process safety management programs within DOE. This paper describes the progress made in implementing effective process safety management programs required by the PSM Standard and discusses some of the trends that have supported efforts to reduce chemical process risks within the DOE. In June of 1994, a survey of chemicals exceeding OSHA PSM or EPA Risk Management Program threshold quantities (TQs) at DOE sites found that there were 22 processes that utilized toxic or reactive chemicals over TQs; there were 13 processes involving flammable gases and liquids over TQs; and explosives manufacturing occurred at 4 sites. Examination of the survey results showed that 12 of the 22 processes involving toxic chemicals involved the use of chlorine for water treatment systems. The processes involving flammable gases and liquids were located at the Strategic Petroleum Reserve and Naval petroleum Reserve sites

  20. Evaluation of concepts for a NET plasma exhaust clean-up system

    International Nuclear Information System (INIS)

    Glugla, M.; Penzhorn, R.D.; Rodriguez, R.; Herbrechter, D.; Dinner, P.; Murdoch, D.

    1990-07-01

    The process steps for the off-gas clean-up and direct recovery of the unburned fuel gases deuterium and tritium are, together with the isotope separation and the fuel preparation, the major subsystems within the fuel cycle of a fusion reactor. A comparison between process concepts largely based on experimental work at KfK and other process alternatives discussed in the literature is carried out and the various options are evaluated on the basis of the process requirements for NET I. The recovery of most of the unburned hydrogen with a palladium/silver permeator is selected as a first step, common to all seven concepts. The remaining impurity stream is processed either catalytically, with the help of getters, or by oxidation followed by reduction of the produced water. The physicochemical basis of each process alternative is discussed and the corresponding chemical flow sheets (flow diagrams and material flow tables) are presented. Concepts employing getters are unattractive because the produce untolerably high amounts of solid waste. Main drawbacks of process options involving an oxidation step are the non-discriminative oxidation of hydrogen and impurities as well as the non-trivial reduction of the produced highly tritiated water at the required elevated throughput. Advantages of the catalytic process are the production of little solid waste, the low steady state inventory and the comparatively easy scale-up. The catalytic process is therefore considered the most promising option for the development of a fuel clean-up process. (orig./HK) [de

  1. Cleaning and Processing RSS measurements for Location Fingerprinting

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun

    2007-01-01

    Handling variations in sampled Received Signal Strength (RSS) is neassary for achieving robust location fingerprinting (LF). Current research has only proposed limited system-specific models for how to handle the cleaning of RSS variations. However, this paper propose a novel model for both...

  2. Flue gas cleaning chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gutberlet, H [VEBA Kraftwerke Ruhr AG, Gelsenkirchen (Germany)

    1996-12-01

    The introduction of modern flue gas cleaning technology into fossil-fueled power stations has repeatedly confronted the power station chemists with new and interesting problems over the last 15 - 20 years. Both flue gas desulphurization by lime washing and catalytic removal of nitrogen oxides are based on simple basic chemical reactions. Owing to the use of readily available starting materials, the production of safe, useful end products and, last but not least, the possibility of implementing all this on an industrial scale by means of efficient process engineering, limestone desulphurization and catalytic removal of nitrogen oxides dominate the world market and, little by little, are becoming still more widespread. The origin and thus the quality of fuels and starting materials, the firing method, the mode of operation and engineering peculiarities in each plant interact in a complex manner. Simple cause/effect relationships are frequently incapable of explaining phenomena; thinking in complex interrelationships is needed. (EG)

  3. Clean-room robot implementation

    International Nuclear Information System (INIS)

    Comeau, J.L.

    1982-01-01

    A robot has been incorporated in a clean room operation in which vacuum tube parts are cleaned just prior to final assembly with a 60 lb/in 2 blast of argon gas. The robot is programmed to pick up the parts, manipulate/rotate them as necessary in the jet pattern and deposit them in a tray precleaned by the robot. A carefully studied implementation plan was followed in the procurement, installation, modification and programming of the robot facility. An unusual configuration of one tube part required a unique gripper design. A study indicated that the tube parts processed by the robot are 12% cleaner than those manually cleaned by an experienced operator

  4. Silvering substrates after CO2 snow cleaning

    Science.gov (United States)

    Zito, Richard R.

    2005-09-01

    There have been some questions in the astronomical community concerning the quality of silver coatings deposited on substrates that have been cleaned with carbon dioxide snow. These questions center around the possible existence of carbonate ions left behind on the substrate by CO2. Such carbonate ions could react with deposited silver to produce insoluble silver carbonate, thereby reducing film adhesion and reflectivity. Carbonate ions could be produced from CO2 via the following mechanism. First, during CO2 snow cleaning, a small amount of moisture can condense on a surface. This is especially true if the jet of CO2 is allowed to dwell on one spot. CO2 gas can dissolve in this moisture, producing carbonic acid, which can undergo two acid dissociations to form carbonate ions. In reality, it is highly unlikely that charged carbonate ions will remain stable on a substrate for very long. As condensed water evaporates, Le Chatelier's principle will shift the equilibrium of the chain of reactions that produced carbonate back to CO2 gas. Furthermore, the hydration of CO2 reaction of CO2 with H20) is an extremely slow process, and the total dehydrogenation of carbonic acid is not favored. Living tissues that must carry out the equilibration of carbonic acid and CO2 use the enzyme carbonic anhydrase to speed up the reaction by a factor of one million. But no such enzymatic action is present on a clean mirror substrate. In short, the worst case analysis presented below shows that the ratio of silver atoms to carbonate radicals must be at least 500 million to one. The results of chemical tests presented here support this view. Furthermore, film lift-off tests, also presented in this report, show that silver film adhesion to fused silica substrates is actually enhanced by CO2 snow cleaning.

  5. Annealing free, clean graphene transfer using alternative polymer scaffolds.

    Science.gov (United States)

    Wood, Joshua D; Doidge, Gregory P; Carrion, Enrique A; Koepke, Justin C; Kaitz, Joshua A; Datye, Isha; Behnam, Ashkan; Hewaparakrama, Jayan; Aruin, Basil; Chen, Yaofeng; Dong, Hefei; Haasch, Richard T; Lyding, Joseph W; Pop, Eric

    2015-02-06

    We examine the transfer of graphene grown by chemical vapor deposition (CVD) with polymer scaffolds of poly(methyl methacrylate) (PMMA), poly(lactic acid) (PLA), poly(phthalaldehyde) (PPA), and poly(bisphenol A carbonate) (PC). We find that optimally reactive PC scaffolds provide the cleanest graphene transfers without any annealing, after extensive comparison with optical microscopy, x-ray photoelectron spectroscopy, atomic force microscopy, and scanning tunneling microscopy. Comparatively, films transferred with PLA, PPA, PMMA/PC, and PMMA have a two-fold higher roughness and a five-fold higher chemical doping. Using PC scaffolds, we demonstrate the clean transfer of CVD multilayer graphene, fluorinated graphene, and hexagonal boron nitride. Our annealing free, PC transfers enable the use of atomically-clean nanomaterials in biomolecule encapsulation and flexible electronic applications.

  6. Annealing free, clean graphene transfer using alternative polymer scaffolds

    International Nuclear Information System (INIS)

    Wood, Joshua D; Doidge, Gregory P; Carrion, Enrique A; Koepke, Justin C; Datye, Isha; Behnam, Ashkan; Hewaparakrama, Jayan; Aruin, Basil; Chen, Yaofeng; Lyding, Joseph W; Kaitz, Joshua A; Dong, Hefei; Haasch, Richard T; Pop, Eric

    2015-01-01

    We examine the transfer of graphene grown by chemical vapor deposition (CVD) with polymer scaffolds of poly(methyl methacrylate) (PMMA), poly(lactic acid) (PLA), poly(phthalaldehyde) (PPA), and poly(bisphenol A carbonate) (PC). We find that optimally reactive PC scaffolds provide the cleanest graphene transfers without any annealing, after extensive comparison with optical microscopy, x-ray photoelectron spectroscopy, atomic force microscopy, and scanning tunneling microscopy. Comparatively, films transferred with PLA, PPA, PMMA/PC, and PMMA have a two-fold higher roughness and a five-fold higher chemical doping. Using PC scaffolds, we demonstrate the clean transfer of CVD multilayer graphene, fluorinated graphene, and hexagonal boron nitride. Our annealing free, PC transfers enable the use of atomically-clean nanomaterials in biomolecule encapsulation and flexible electronic applications. (paper)

  7. Cheap non-toxic non-corrosive method of glass cleaning evaluated by contact angle, AFM, and SEM-EDX measurements.

    Science.gov (United States)

    Dey, Tania; Naughton, Daragh

    2017-05-01

    Glass surface cleaning is the very first step in advanced coating deposition and it also finds use in conserving museum objects. However, most of the wet chemical methods of glass cleaning use toxic and corrosive chemicals like concentrated sulfuric acid (H 2 SO 4 ), piranha (a mixture of concentrated sulfuric acid and 30% hydrogen peroxide), and hydrogen fluoride (HF). On the other hand, most of the dry cleaning techniques like UV-ozone, plasma, and laser treatment require costly instruments. In this report, five eco-friendly wet chemical methods of glass cleaning were evaluated in terms of contact angle (measured by optical tensiometer), nano-scale surface roughness (measured by atomic force microscopy or AFM), and elemental composition (measured by energy dispersive x-ray spectroscopy or SEM-EDX). These glass cleaning methods are devoid of harsh chemicals and costly equipment, hence can be applied in situ in close proximity with plantation such as greenhouse or upon subtle objects such as museum artifacts. Out of these five methods, three methods are based on the chemical principle of chelation. It was found that the citric acid cleaning method gave the greatest change in contact angle within the hydrophilic regime (14.25° for new glass) indicating effective cleansing and the least surface roughness (0.178 nm for new glass) indicating no corrosive effect. One of the glass sample showed unique features which were traced backed to the history of the glass usage.

  8. Cleaning and decontamination: Experimental feedback from PHENIX

    International Nuclear Information System (INIS)

    Masse, F.; Rodriguez, G.

    1997-01-01

    After the first few years of operation of PHENIX, it proved necessary to clean, then decontaminate sodium-polluted components, particularly large components such as the intermediate heat exchangers (IHX) and the primary pumps (PP). Ibis document presents the evolution of the cleaning and decontamination processes used, and specifies the reasons for this evolution. As regards the cleaning, experimental feedback and a greater rigour with respect to the hydrogen hazard have resulted in a modification of the process. The new cleaning process used at present (since 1994) is described in greater detail in this document. The main steps are: cold CO 2 bubbling in water, followed by hot CO 2 bubbling, spraying phase, then drying for inspection before immersion. In order to optimize and validate the process, the cleaning and decontamination plant has been highly instrumented, which, in particular, has allowed confirmation of the contention that the major part of the sodium is eliminated during the bubbling phases. With respect to decontamination, the objective is to perfect an efficient process that allows both human intervention with no particular biological shield for repair or maintenance of the components, and requalification of the materials after the decontamination operation. Owing to the high operating temperature of Fast Breeder Reactor components (400 to 550 deg. C), the activated corrosion products deposited on the components melt into the metal. The decontamination process therefore consists in either dissolving the deposits on the surface, or dissolving a thickness of about less than ten micrometers of the base metal. The reference process for austenitic-type steels is the SPm process, which consists in immersing the component in a sulphuric-phosphoric bath (sulphuric acid and phosphoric acid) at a temperature of 60 deg. C for 6 hours. The problem linked to this process is the treatment of the effluents that are produced, particularly phosphate releases. A

  9. Conceptual Chemical Process Design for Sustainability.

    Science.gov (United States)

    This chapter examines the sustainable design of chemical processes, with a focus on conceptual design, hierarchical and short-cut methods, and analyses of process sustainability for alternatives. The chapter describes a methodology for incorporating process sustainability analyse...

  10. Lasers in chemical processing

    International Nuclear Information System (INIS)

    Davis, J.I.

    1982-01-01

    The high cost of laser energy is the crucial issue in any potential laser-processing application. It is expensive relative to other forms of energy and to most bulk chemicals. We show those factors that have previously frustrated attempts to find commercially viable laser-induced processes for the production of materials. Having identified the general criteria to be satisfied by an economically successful laser process and shown how these imply the laser-system requirements, we present a status report on the uranium laser isotope separation (LIS) program at the Lawrence Livermore National Laboratory

  11. Frequent use of household cleaning products is associated with rhinitis in Chinese children.

    Science.gov (United States)

    Liu, Xudong; Lao, Xiang Qian; Wong, Claudie Chiu-Yi; Tan, Lixing; Zhang, Zilong; Wong, Tze Wai; Tse, Lap-Ah; Lau, Arthur P S; Yu, Ignatius T S

    2016-09-01

    Despite the popular use of household cleaning products worldwide, there is no published study investigating the health effects of these products on rhinitis in children. We sought to investigate the household use of cleaning products and rhinitis patterns in Chinese children. A total of 2299 children were recruited from 21 primary schools with wide geographic coverage in Hong Kong. Self-administered questionnaires were completed by parents/guardians to collect detailed information on respiratory symptoms and household use of 14 types of chemical cleaning products, as well as clean water. Students were categorized into 4 mutually exclusive rhinitis patterns (never, occasional, frequent, and persistent). The total chemical burden (TCB) score was used as the exposure indicator by calculating the total time of exposure to the 14 cleaning products. Multinomial logistic regression was used to assess the relationship between rhinitis patterns and the use of household cleaning products. Every 10-unit increment of TCB score was associated with an increase in the odds of occasional (odds ratio [OR], 1.21; 95% CI, 1.05-1.41), frequent (OR, 1.36; 95% CI, 1.13-1.60), and persistent (OR, 1.21; 95% CI, 1.01-1.56) rhinitis after adjustment for a wide range of potential confounders. Compared with the children within the lowest tertile of TCB scores, the adjusted ORs of occasional, frequent, and persistent rhinitis in children within the highest tertile were 1.29 (95% CI, 1.01-1.65), 1.97 (95% CI, 1.40-2.76), and 1.67 (95% CI, 1.10-2.54), respectively. Frequent use of chemical cleaning products at home is associated with an increase in the odds of rhinitis in Chinese primary school children. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Fiscal 2000 achievement report. Research and development of semiconductor CVD chamber cleaning systems for electronic device manufacturing using new alternative gas instead of SF6, PFCs, and other gases; 2000 nendo sokkoteki kakushinteki energy kankyo gijutsu kaihatsu seika hokokusho. SF6 tou ni daitaisuru gasu wo riyo shita denshi debaisu seizo cleaning system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The efforts aim to develop a CVD (chemical vapor deposition) mechanism cleaning gas with less environmental impact such as global warming and a CVD process using the same. The candidate gas synthesizing study for the development of such a gas continues from the preceding fiscal year. In addition, various candidate gases and tentatively synthesized gases are evaluated for their cleaning performance using a simplified experimental system. As the result, patent applications were filed for three novel alternative gases low in environmental impact and high in cleaning performance. In the research and development of CVD processes, a verification test process is developed for the evaluation of alternative gases at the real system level using a large CVD evaluation system. Studies are also made in which some existing gases are utilized to improve on CVD cleaning efficiency and to reduce greenhouse gas emissions. In relation to the process, one domestic patent application is made, and three essays are presented at an international conference on electrochemistry in the United States. (NEDO)

  13. Twenty-second DOE/NRC nuclear air cleaning and treatment conference

    International Nuclear Information System (INIS)

    Bellamy, R.R.; Moeller, D.W.; First, M.W.

    1992-01-01

    The Twenty-Second Department of Energy/Nuclear Regulatory Commission Nuclear Air Cleaning and Treatment Conference was held Aug. 24-27, 1992, in Denver, Colo. A total of 224 air-cleaning specialists attended the conference. The United States and 12 foreign countries were represented, and the specialists were affiliated with government agencies, educational institutions, and all aspects of the nuclear industry, including utilities, architect engineers, equipment suppliers, and consultants. Several major topics were discussed, similar to areas covered at previous conferences: chemical processing off-gas cleaning; particulate filler developments, including filter testing, performance, and response to physical stress,adsorber testing and performance, including laboratory and in-place testing; waste management; system operation; codes and standards; and advanced nuclear power plants. The conference continued to provide an effective forum for direct interchange of information of both a practical and theoretical nature. International participation and interest continues, as evidenced by over 40% of the papers being sponsored by foreign interests and almost 20% of the attendees being from outside the United States. The potential for new, safer nuclear plants of an advanced design was an optimistic note during the conference. Regulatory authorities are playing a major role in providing guidance in the development of safety goals and other technical criteria for these new installations

  14. Preliminary cleaning tests on candidate materials for APS beamline and front end UHV components

    International Nuclear Information System (INIS)

    Nielsen, R.; Kuzay, T.M.

    1992-01-01

    Comparative cleaning tests have been done on four candidate materials for use in APS beamline and front-end vacuum components. These materials are 304 SS, 304L SS, OFHC copper, and Glidcop* (Cu-Al 2 O 3 )- Samples of each material were prepared and cleaned using two different methods. After cleaning, the sample surfaces were analyzed using ESCA (Electron Spectography for Chemical Analysis). Uncleaned samples were used as a reference. The cleaning methods and surface analysis results are further discussed

  15. Analysis of selective laser cleaning of patina on bronze coins

    International Nuclear Information System (INIS)

    Buccolieri, G; Nassisi, V; Castellano, A; Di Giulio, M; Giuffreda, E; Delle Side, D; Velardi, L; Torrisi, L; Buccolieri, A

    2014-01-01

    The patina, is the result of a large number of chemical, electrochemical and physical processes which occur spontaneously during interaction of metal surfaces with the environment. In this work we want to analyze and remove the patina in artefacts, exposed to atmosphere for various decades. Here, experimental results about the laser cleaning of bronze coins by KrF (248 nm) and Nd:YAG (532 nm) lasers are reported. Both laser wavelengths were efficient to reduce the chlorine concentration on the surface of the coins more than 80 %, as demonstrated by Energy Dispersive X-Ray Fluorescence analyses.

  16. Chemical cleaning-associated generation of dissolved organic matter and halogenated byproducts in ceramic MBR: Ozone versus hypochlorite.

    Science.gov (United States)

    Sun, Huifang; Liu, Hang; Han, Jiarui; Zhang, Xiangru; Cheng, Fangqin; Liu, Yu

    2018-04-24

    This study characterized the dissolved organic matter (DOM) and byproducts generated after the exposure of activated sludge to ozone and NaClO in ceramic MBR. It was found that NaClO triggered more significant release of DOM than ozone. Proteins with the molecular weight greater than 20 kDa and humic acid like-substances were the principal components of DOM generated by NaClO, while ozone was found to effectively degrade larger biopolymers to low molecular weight substances. The results showed that more than 80% of DOM generated by NaClO and ozone could pass through the 0.2-μm ceramic membrane. Furthermore, total organic chlorine (TOCl) was determined to be the principal species of halogenated byproducts in both cases, while the generation of TOCl by NaClO was much more significant than that by ozone. Only a small fraction of TOCl was removed by the 0.2-μm ceramic membrane. More importantly, the toxic bioassays further revealed that the supernatant of sludge suspension and permeate in the MBR with NaClO cleaning exhibited higher developmental toxicity to the polychaete embryos than those by ozone. The results clearly showed that on-line chemical cleaning with ozone should be a more eco-friendly and safer approach for sustaining long-term membrane permeability in ceramic MBR. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Carbon dioxide cleaning pilot project

    International Nuclear Information System (INIS)

    Knight, L.; Blackman, T.E.

    1994-01-01

    In 1989, radioactive-contaminated metal at the Rocky Flats Plant (RFP) was cleaned using a solvent paint stripper (Methylene chloride). One-third of the radioactive material was able to be recycled; two-thirds went to the scrap pile as low-level mixed waste. In addition, waste solvent solutions also required disposal. Not only was this an inefficient process, it was later prohibited by the Resource Conservation and Recovery Act (RCRA), 40 CFR 268. A better way of doing business was needed. In the search for a solution to this situation, it was decided to study the advantages of using a new technology - pelletized carbon dioxide cleaning. A proof of principle demonstration occurred in December 1990 to test whether such a system could clean radioactive-contaminated metal. The proof of principle demonstration was expanded in June 1992 with a pilot project. The purpose of the pilot project was three fold: (1) to clean metal so that it can satisfy free release criteria for residual radioactive contamination at the Rocky Flats Plant (RFP); (2) to compare two different carbon dioxide cleaning systems; and (3) to determine the cost-effectiveness of decontamination process in a production situation and compare the cost of shipping the metal off site for waste disposal. The pilot project was completed in August 1993. The results of the pilot project were: (1) 90% of those items which were decontaminated, successfully met the free release criteria , (2) the Alpheus Model 250 was selected to be used on plantsite and (3) the break even cost of decontaminating the metal vs shipping the contaminated material offsite for disposal was a cleaning rate of 90 pounds per hour, which was easily achieved

  18. The Dalian National Laboratory for Clean Energy.

    Science.gov (United States)

    Zhang, Tao; Li, Can; Bao, Xinhe

    2012-05-01

    The Dalian Institute of Chemical Physics (DICP), Chinese Academy of Sciences conducts fundamental and applied research towards chemistry and chemical engineering, with strong competence in the development of new technologies. The research in this special issue, containing 19 papers, features some of the DICP's best work on sustainable energy, use of environmental resources, and advanced materials within the framework of the Dalian National Laboratory for Clean Energy (DNL). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. A Critical Review on Processes and Energy Profile of the Australian Meat Processing Industry

    Directory of Open Access Journals (Sweden)

    Ihsan Hamawand

    2017-05-01

    Full Text Available This review article addresses wastewater treatment methods in the red meat processing industry. The focus is on conventional chemicals currently in use for abattoir wastewater treatment and energy related aspects. In addition, this article discusses the use of cleaning and sanitizing agents at the meat processing facilities and their effect on decision making in regard to selecting the treatment methods. This study shows that cleaning chemicals are currently used at a concentration of 2% to 3% which will further be diluted with the bulk wastewater. For example, for an abattoir that produces 3500 m3/day wastewater and uses around 200 L (3% acid and alkaline chemicals, the final concentration of these chemical will be around 0.00017%. For this reason, the effects of these chemicals on the treatment method and the environment are very limited. Chemical treatment is highly efficient in removing soluble and colloidal particles from the red meat processing industry wastewater. Actually, it is shown that, if chemical treatment has been applied, then biological treatment can only be included for the treatment of the solid waste by-product and/or for production of bioenergy. Chemical treatment is recommended in all cases and especially when the wastewater is required to be reused or released to water streams. This study also shows that energy consumption for chemical treatment units is insignificant while efficient compared to other physical or biological units. A combination of a main (ferric chloride and an aid coagulant has shown to be efficient and cost-effective in treating abattoir wastewater. The cost of using this combination per cubic meter wastewater treated is 0.055 USD/m3 compared to 0.11 USD/m3 for alum and the amount of sludge produced is 77% less than that produced by alum. In addition, the residues of these chemicals in the wastewater and the sludge have a positive or no impact on biological processes. Energy consumption from a small

  20. Apparatuses, Systems and Methods for Cleaning Photovoltaic Devices

    KAUST Repository

    Eitelhuber, Georg

    2013-02-14

    Embodiments of solar panel cleaning apparatuses, solar panel cleaning systems, and solar panel cleaning methods are disclosed. In certain embodiments, the disclosed solar panel cleaning apparatuses, systems and methods do may not require any water or other cleaning liquids in the whole cleaning process, which makes them prominent well suited in for water-deficit environments such as deserts. In one embodiment, the solar panel cleaning apparatus comprises one or more rotatable brushes each having a rotational axis and a drive configured to move each of the one or more rotatable brushes in a direction that is not perpendicular to the rotational axis. The solar panel cleaning apparatus is may be configured such that the angle of the rotational axis of at least one of the one or more rotatable brushes is adjustable relative to the direction of travel.

  1. Fabrication of free standing anodic titanium oxide membranes with clean surface using recycling process.

    Science.gov (United States)

    Meng, Xianhui; Lee, Tae-Young; Chen, Huiyu; Shin, Dong-Wook; Kwon, Kee-Won; Kwon, Sang Jik; Yoo, Ji-Beom

    2010-07-01

    Large area of self-organized, free standing anodic titanium oxide (ATO) nanotube membranes with clean surfaces were facilely prepared to desired lengths via electrochemical anodization of highly pure Ti sheets in an ethylene glycol electrolyte, with a small amount of NH4F and H2O at 50 V, followed by self-detachment of the ATO membrane from the Ti substrate using recycling processes. In the first anodization step, the nanowire oxide layer existed over the well-arranged ATO nanotube. After sufficiently rinsing with water, the whole ATO layer was removed from the Ti sheet by high pressure N2 gas, and a well-patterned dimple layer with a thickness of about 30 nm existed on the Ti substrate. By using these naturally formed nano-scale pits as templates, in the second and third anodization process, highly ordered, vertically aligned, and free standing ATO membranes with the anodic aluminum oxide (AAO)-like clean surface were obtained. The inter-pore distance and diameter was 154 +/- 2 nm and 91+/- 2 nm, the tube arrays lengths for 25 and 46 hours were 44 and 70 microm, respectively. The present study demonstrates a simple approach to producing high quality, length controllable, large area TiO2 membrane.

  2. Gas turbine cleaning upgrade (compressor wash)

    Energy Technology Data Exchange (ETDEWEB)

    Asplund, P [Gas Turbine Efficiency, Jarfalla (Sweden)

    1999-12-31

    The influence of gas turbine degradation on operating costs is high. Gas turbine cleaning is one of many actions taken for power recovery and is to consider as preventive maintenance. It is generally performed within the industrial field and occasionally within the aero sector. In order to meet the gas turbine development win high blade loads and ever-increasing temperatures, together with emission Aces and environmental regulations, more efficient and careful cleaning methods are needed. Following a survey about potentials for cost reduction in gas turbine operation a new man-hour and water saving cleaning method has been evaluated for a standard process. Compared with traditional cleaning methods, the new method is water,- cost,- weight and space saving due to a new washing technique. Traditional methods are based on using different nozzles for ON and OFF-line cleaning, which rise the demand for complicated systems. In the new method the same nozzle installation, same liquid flow and pressure is used for both ON and OFF-line cleaning. This gives a cost reduction of appr. 20.000 - 30.000 USD per gas turbine depending on installation and size. Evaluation of the new method shows significantly improved ON -line cleaning performance and thus OFF -line cleaning is required only during scheduled stops. (orig.) 10 refs.

  3. Gas turbine cleaning upgrade (compressor wash)

    Energy Technology Data Exchange (ETDEWEB)

    Asplund, P. [Gas Turbine Efficiency, Jarfalla (Sweden)

    1998-12-31

    The influence of gas turbine degradation on operating costs is high. Gas turbine cleaning is one of many actions taken for power recovery and is to consider as preventive maintenance. It is generally performed within the industrial field and occasionally within the aero sector. In order to meet the gas turbine development win high blade loads and ever-increasing temperatures, together with emission Aces and environmental regulations, more efficient and careful cleaning methods are needed. Following a survey about potentials for cost reduction in gas turbine operation a new man-hour and water saving cleaning method has been evaluated for a standard process. Compared with traditional cleaning methods, the new method is water,- cost,- weight and space saving due to a new washing technique. Traditional methods are based on using different nozzles for ON and OFF-line cleaning, which rise the demand for complicated systems. In the new method the same nozzle installation, same liquid flow and pressure is used for both ON and OFF-line cleaning. This gives a cost reduction of appr. 20.000 - 30.000 USD per gas turbine depending on installation and size. Evaluation of the new method shows significantly improved ON -line cleaning performance and thus OFF -line cleaning is required only during scheduled stops. (orig.) 10 refs.

  4. Integrated hot fuel gas cleaning for advanced gasification combined cycle process

    Energy Technology Data Exchange (ETDEWEB)

    Nieminen, M.; Kangasmaa, K.; Laatikainen, J.; Staahlberg, P.; Kurkela, E. [VTT Energy, Espoo (Finland). Gasification and Advanced Combustion

    1996-12-01

    The fate of halogens in pressurised fluidized-bed gasification and hot gas filtration is determined. Potential halogen removal sorbents, suitable for integrated hot gas cleaning, are screened and some selected sorbents are tested in bench scale. Finally, halogen removal results are verified using the PDU-scale pressurised fluidized-bed gasification and integrated hot gas cleaning facilities of VTT. The project is part of the JOULE II Extension programme of the European Union. (author)

  5. Efficacy of low-pressure foam cleaning compared to conventional cleaning methods in the removal of bacteria from surfaces associated with convenience food.

    Science.gov (United States)

    Lambrechts, A A; Human, I S; Doughari, J H; Lues, J F R

    2014-09-01

    Food borne illnesses and food poisoning are cause for concern globally. The diseases are often caused by food contamination with pathogenic bacteria due largely to poor sanitary habits or storage conditions. Prevalence of some bacteria on cleaned and sanitised food contact surfaces from eight convenience food plants in Gauteng (South Africa) was investigated with the view to evaluate the efficacy of the cleaning methods used with such food contact surfaces. The microbial load of eight convenience food manufacturing plants was determined by sampling stainless steel food contact surfaces after they had been cleaned and sanitised at the end of a day's shift. Samples were analysed for Total Plate Count (TPC), Escherichia coli, Salmonella species, Staphylococcus aureus and Listeria species. Results showed that 59 % of the total areas sampled for TPC failed to comply with the legal requirements for surfaces, according to the Foodstuffs, Cosmetics and Disinfectants Act ( 0.05) in terms of Listeria species isolates obtained from both cleaning methods. The LPF method proved to be the superior cleaning option for lowering TPC counts. Regardless of cleaning method used, pathogens continued to flourish on various surfaces, including dry stainless steel, posing a contamination hazard for a considerable period depending on the contamination level and type of pathogen. Intensive training for proper chemical usage and strict procedural compliance among workers for efficient cleaning procedures is recommended.

  6. Staying sticky: contact self-cleaning of gecko-inspired adhesives.

    Science.gov (United States)

    Mengüç, Yigit; Röhrig, Michael; Abusomwan, Uyiosa; Hölscher, Hendrik; Sitti, Metin

    2014-05-06

    The exceptionally adhesive foot of the gecko remains clean in dirty environments by shedding contaminants with each step. Synthetic gecko-inspired adhesives have achieved similar attachment strengths to the gecko on smooth surfaces, but the process of contact self-cleaning has yet to be effectively demonstrated. Here, we present the first gecko-inspired adhesive that has matched both the attachment strength and the contact self-cleaning performance of the gecko's foot on a smooth surface. Contact self-cleaning experiments were performed with three different sizes of mushroom-shaped elastomer microfibres and five different sizes of spherical silica contaminants. Using a load-drag-unload dry contact cleaning process similar to the loads acting on the gecko foot during locomotion, our fully contaminated synthetic gecko adhesives could recover lost adhesion at a rate comparable to that of the gecko. We observed that the relative size of contaminants to the characteristic size of the microfibres in the synthetic adhesive strongly determined how and to what degree the adhesive recovered from contamination. Our approximate model and experimental results show that the dominant mechanism of contact self-cleaning is particle rolling during the drag process. Embedding of particles between adjacent fibres was observed for particles with diameter smaller than the fibre tips, and further studied as a temporary cleaning mechanism. By incorporating contact self-cleaning capabilities, real-world applications of synthetic gecko adhesives, such as reusable tapes, clothing closures and medical adhesives, would become feasible.

  7. Chemical reagent and process for refuse disposal

    International Nuclear Information System (INIS)

    Somerville, R.B.; Fan, L.T.

    1989-01-01

    A process for treating refuse by mixing them with a reactive chemical and a puzzolana-type material. Said chemical includes a retarding agent which modifies the viscosity and an accelerating agent. (author)

  8. Canyon solvent cleaning with solid adsorbents

    International Nuclear Information System (INIS)

    Reif, D.J.

    1987-01-01

    The HM Process at the Savannah River Plant (SRP) uses 7.5% tributyl phosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, product decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown that carbonate washing, although removing residual solvent activity, does not remove binding ligands that hold fission products in the solvent. Treatment of solvent with a solid adsorbent removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale adsorption process and the use of the process to clean HM Process first cycle solvent are presented

  9. MRI of chemical reactions and processes.

    Science.gov (United States)

    Britton, Melanie M

    2017-08-01

    As magnetic resonance imaging (MRI) can spatially resolve a wealth of molecular information available from nuclear magnetic resonance (NMR), it is able to non-invasively visualise the composition, properties and reactions of a broad range of spatially-heterogeneous molecular systems. Hence, MRI is increasingly finding applications in the study of chemical reactions and processes in a diverse range of environments and technologies. This article will explain the basic principles of MRI and how it can be used to visualise chemical composition and molecular properties, providing an overview of the variety of information available. Examples are drawn from the disciplines of chemistry, chemical engineering, environmental science, physics, electrochemistry and materials science. The review introduces a range of techniques used to produce image contrast, along with the chemical and molecular insight accessible through them. Methods for mapping the distribution of chemical species, using chemical shift imaging or spatially-resolved spectroscopy, are reviewed, as well as methods for visualising physical state, temperature, current density, flow velocities and molecular diffusion. Strategies for imaging materials with low signal intensity, such as those containing gases or low sensitivity nuclei, using compressed sensing, para-hydrogen or polarisation transfer, are discussed. Systems are presented which encapsulate the diversity of chemical and physical parameters observable by MRI, including one- and two-phase flow in porous media, chemical pattern formation, phase transformations and hydrodynamic (fingering) instabilities. Lastly, the emerging area of electrochemical MRI is discussed, with studies presented on the visualisation of electrochemical deposition and dissolution processes during corrosion and the operation of batteries, supercapacitors and fuel cells. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  10. Low temperature radio-chemical energy conversion processes

    International Nuclear Information System (INIS)

    Gomberg, H.J.

    1986-01-01

    This patent describes a radio-chemical method of converting radiated energy into chemical energy form comprising the steps of: (a) establishing a starting chemical compound in the liquid phase that chemically reacts endothermically to radiation and heat energy to produce a gaseous and a solid constituent of the compound, (b) irradiating the compound in its liquid phase free of solvents to chemically release therefrom in response to the radiation the gaseous and solid constituents, (c) physically separating the solid and gaseous phase constituents from the liquid, and (d) chemically processing the constituents to recover therefrom energy stored therein by the irradiation step (b)

  11. Dry-cleaning with high-pressure carbon dioxide

    NARCIS (Netherlands)

    Van Roosmalen, M.J.E.

    2003-01-01

    Dry-cleaning is a process for removing soils and stains from fabrics and garments which uses a non-aqueous solvent with detergent added. The currently most used dry-cleaning solvent is perchloroethylene (PER), which is toxic, environmentally harmful and suspected to be carcinogenic. Carbon dioxide

  12. Inhibition of the Nitrification Process of Activated Sludge Micro-Organism by Scrubber Water from an Industrial Flue Gas Cleaning Process

    DEFF Research Database (Denmark)

    Thomsen, Jens Peter

    2007-01-01

    the nitrogen removal. A major sewage cleaning plant in the southern part of Denmark is a recipient of industrial sewage from a major fish meal industry. Severe nitrification inhibition was observed in scrubber water from an incineration of process air, and the processes that lead to the production were stopped......The microbial transformation of ammonia to nitrate, the nitrification, is a central process in the nitrogen biogeochemical cycle. In a modern wastewater treatment plant, the nitrification process is a key process in the removal of nitrogen and inhibitory compounds in sewage can seriously affect....... In order to investigate the relation between incineration temperatures and the production of inhibitory compounds, the process air was burned at temperatures from 800°C to 1000°C. The termically affected condensate was collected and the nitrification inhibition effect of the condensate was tested using...

  13. Safety in the Chemical Laboratory: Tested Disposal Methods for Chemical Wastes from Academic Laboratories.

    Science.gov (United States)

    Armour, M. A.; And Others

    1985-01-01

    Describes procedures for disposing of dichromate cleaning solution, picric acid, organic azides, oxalic acid, chemical spills, and hydroperoxides in ethers and alkenes. These methods have been tested under laboratory conditions and are specific for individual chemicals rather than for groups of chemicals. (JN)

  14. Sodium removal from CSRDM lower part by water vapour - CO2 process

    International Nuclear Information System (INIS)

    Sundar Raj, S.I.; Sreedhar, B.K.; Gurumoorthy, K.; Rajan, K.K.; Kalyanasundaram, P.; Rajan, M.; Vaidyanathan, G.

    2006-01-01

    Sodium is the primary and secondary coolant in fast reactors. Primary and secondary circuits components like Control and Safety Rod Drive Mechanism (CSRDM), pumps, heat exchangers etc. handle liquid sodium. Sodium has good affinity to oxygen and reacts vigorously with water. Hence sodium cleaning is the first and important activity in the maintenance of the components. In reactor components this cleaning process also helps in removing a major part of radioactive contaminants after which they are subjected to chemical decontamination. There are several methods available for removing sodium from components. Out of these, the water vapour-CO 2 process is selected for large components such as pumps, heat exchangers etc. while steam cleaning is used for the core sub assemblies. The cleaning processes are to be closely monitored to ensure safety because the release of hydrogen is to be kept below 4 % during the process. This paper discusses the in house facility and the experience in the successful use of the process in the cleaning of CSRDM. (author)

  15. Cleaning and dewatering fine coal

    Science.gov (United States)

    Yoon, Roe-Hoan; Eraydin, Mert K.; Freeland, Chad

    2017-10-17

    Fine coal is cleaned of its mineral matter impurities and dewatered by mixing the aqueous slurry containing both with a hydrophobic liquid, subjecting the mixture to a phase separation. The resulting hydrophobic liquid phase contains coal particles free of surface moisture and droplets of water stabilized by coal particles, while the aqueous phase contains the mineral matter. By separating the entrained water droplets from the coal particles mechanically, a clean coal product of substantially reduced mineral matter and moisture contents is obtained. The spent hydrophobic liquid is separated from the clean coal product and recycled. The process can also be used to separate one type of hydrophilic particles from another by selectively hydrophobizing one.

  16. Process analytical chemistry applied to actinide waste streams

    International Nuclear Information System (INIS)

    Day, R.S.

    1994-01-01

    The Department of Energy is being called upon to clean up it's legacy of waste from the nuclear complex generated during the cold war period. Los Alamos National Laboratory is actively involved in waste minimization and waste stream polishing activities associated with this clean up. The Advanced Testing Line for Actinide Separations (ATLAS) at Los Alamos serves as a developmental test bed for integrating flow sheet development of nitric acid waste streams with process analytical chemistry and process control techniques. The wastes require processing in glove boxes because of the radioactive components, thus adding to the difficulties of making analytical measurements. Process analytical chemistry methods provide real-time chemical analysis in support of existing waste stream operations and enhances the development of new waste stream polishing initiatives. The instrumentation and methods being developed on ATLAS are designed to supply near-real time analyses on virtually all of the chemical parameters found in nitric acid processing of actinide waste. These measurements supply information on important processing parameters including actinide oxidation states, free acid concentration, interfering anions and metal impurities

  17. Clean solutions to the incoming wafer quality impact on lithography process yield limits in a dynamic copper/low-k research and development environment

    Science.gov (United States)

    Lysaght, Patrick S.; Ybarra, Israel; Sax, Harry; Gupta, Gaurav; West, Michael; Doros, Theodore G.; Beach, James V.; Mello, Jim

    2000-06-01

    The continued growth of the semiconductor manufacturing industry has been due, in large part, to improved lithographic resolution and overlay across increasingly larger chip areas. Optical lithography continues to be the mainstream technology for the industry with extensions of optical lithography being employed to support 180 nm product and process development. While the industry momentum is behind optical extensions to 130 nm, the key challenge will be maintaining an adequate and affordable process latitude (depth of focus/exposure window) necessary for 10% post-etch critical dimension (CD) control. If the full potential of optical lithography is to be exploited, the current lithographic systems can not be compromised by incoming wafer quality. Impurity specifications of novel Low-k dielectric materials, plating solutions, chemical-mechanical planarization (CMP) slurries, and chemical vapor deposition (CVD) precursors are not well understood and more stringent control measures will be required to meet defect density targets as identified in the National Technology Roadmap for Semiconductors (NTRS). This paper identifies several specific poor quality wafer issues that have been effectively addressed as a result of the introduction of a set of flexible and reliable wafer back surface clean processes developed on the SEZ Spin-Processor 203 configured for processing of 200 mm diameter wafers. Patterned wafers have been back surface etched by means of a novel spin process contamination elimination (SpCE) technique with the wafer suspended by a dynamic nitrogen (N2) flow, device side down, via the Bernoulli effect. Figure 1 illustrates the wafer-chuck orientation within the process chamber during back side etch processing. This paper addresses a number of direct and immediate benefits to the MicraScan IIITM deep-ultraviolet (DUV) step-and-scan system at SEMATECH. These enhancements have resulted from the resolution of three significant problems: (1) back surface

  18. [Effects of rice cleaning and cooking process on the residues of flutolanil, fenobucarb, silafluofen and buprofezin in rice].

    Science.gov (United States)

    Satoh, Motoaki; Sakaguchi, Masayuki; Kobata, Masakazu; Sakaguchi, Yoko; Tanizawa, Haruna; Miura, Yuri; Sasano, Ryoichi; Nakanishi, Yutaka

    2003-02-01

    We studied the effect of cleaning and cooking on the residues of flutolanil, fenobucarb, silafluofen and buprofezin in rice. The rice had been sprayed in a paddy field in Wakayama city, with 3 kinds of pesticide application protocols: spraying once at the usual concentration of pesticides, repeated spraying (3 times) with the usual concentration of pesticides and spraying once with 3 times the usual concentration of pesticides. The residue levels of pesticide decreased during the rice cleaning process. Silafluofen, which has a higher log Pow value, remained in the hull of the rice. Fenobucarb, which has a lower log Pow value, penetrated inside the rice. The residue concentration of pesticide in polished rice was higher than that in pre-washed rice processed ready for cooking. During the cooking procedure, the reduction of pesticides in polished rice was higher than that in brown rice.

  19. Book of abstracts Chemical Engineering: IV All-Russian Conference on chemical engineering, All-Russian Youth Conference on chemical engineering, All-Russian school on chemical engineering for young scientists and specialists. Chemical engineering of nanomaterials. Energy- and resource-saving chemical-engineering processes and problems of their intensification. Processes and apparatuses of chemical engineering, chemical cybernetics. Ecological problems of chemical engineering and related fields

    International Nuclear Information System (INIS)

    Zakhodyaeva, Yu.A.; Belova, V.V.

    2012-01-01

    In the given volume of abstracts of the IV All-Russian Conference on chemical engineering, All-Russian Youth Conference on chemical engineering, All-Russian school on chemical engineering for young scientists and specialists (Moscow, March 18-23, 2012) there are the abstracts of the reports concerning chemical engineering of nanomaterials, energy- and resource-saving chemical-engineering processes, processes and apparatuses of chemical engineering, chemical cybernetics, ecological problems of chemical engineering and related fields. The abstracts deal with state-of-the-art and future development of theoretical and experimental investigations as well as with experience in practical realization of development works in the field of chemical engineering and relative areas [ru

  20. Clean Slate 1 revegetation and monitoring plan

    International Nuclear Information System (INIS)

    Anderson, D.C.; Hall, D.B.

    1997-07-01

    This document constitutes a reclamation plan for the short-term and long-term stabilization of land disturbed by activities associated with the cleanup of radionuclide contaminated surface soil at the Clean Slate 1 site. This document has been prepared to provide general reclamation practices and procedures that will be followed during restoration of the cleanup site. The results of reclamation trials at Area 11, Area 19 and more recently the reclamation demonstration plots at the Double Tracks cleanup site, have been summarized and incorporated into this reclamation and monitoring plan. The plan also contains procedures for monitoring both the effectiveness and success of short-term and long-term soil stabilization. The Clean Slate 1 site is located on the Tonopah Test Range. The surface soils were contaminated as a result of the detonation of a device containing plutonium and depleted uranium using chemical explosives. Short-term stabilization consists of the application of a chemical soil stabilizer that is applied immediately following excavation of the contaminated soils to minimize Pu resuspension. Long-term stabilization is accomplished by the establishment of a permanent vegetation

  1. Chemicals Industry New Process Chemistry Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2000-08-01

    The Materials Technology I workshop was held in November 1998 to address future research needs for materials technology that will support the chemical industry. Areas covered included disassembly, recovery, reuse and renewable technology; new materials; and materials measurement and characterization. The Materials Technology II workshop was held in September 1999 and covered additives, modeling and prediction and an additional segment on new materials. Materials Technology Institute (MTI) for the Chemical Process Industries, Inc. and Air Products & Chemicals lead the workshops. The Materials Technology Roadmap presents the results from both workshops.

  2. A centrifuge CO2 pellet cleaning system

    International Nuclear Information System (INIS)

    Foster, C.A.; Fisher, P.W.; Nelson, W.D.; Schechter, D.E.

    1993-01-01

    Centrifuge-based cryogenic pellet accelerator technology, originally developed at Oak Ridge National Laboratory (ORNL) for the purpose of refueling fusion reactors with high-speed pellets of frozen deuterium/tritium,is now being developed as a method of cleaning without the use of conventional solvents. In these applications large quantities of pellets made of frozen CO 2 or argon are accelerated in a high-speed rotor. The accelerated pellet stream is used to clean or etch surfaces. The advantage of this system is that the spent pellets and debris resulting from the cleaning process can be filtered leaving only the debris for disposal. This paper discusses the centrifuge CO 2 pellet cleaning system, the physics model of the pellet impacting the surface, the centrifuge apparatus, and some initial cleaning and etching tests

  3. Collodion-reinforcement and plasma-cleaning of target foils

    Science.gov (United States)

    Stoner, John O.

    2002-03-01

    The preparation of evaporated target foils can often be facilitated by use of collodion coatings either on the substrate sides or on the exterior surfaces of the foils. Later, such coatings must usually be removed. Cleaning of a foil is necessary if thin layers of adhesives have crept onto the foil. Removal and/or cleaning can often be done satisfactorily with an oxygen plasma. Apparatus and procedures used for this are described. Foils that were cleaned successfully, and some that were incompatible with the cleaning process are listed.

  4. Collodion-reinforcement and plasma-cleaning of target foils

    International Nuclear Information System (INIS)

    Stoner, John O.

    2002-01-01

    The preparation of evaporated target foils can often be facilitated by use of collodion coatings either on the substrate sides or on the exterior surfaces of the foils. Later, such coatings must usually be removed. Cleaning of a foil is necessary if thin layers of adhesives have crept onto the foil. Removal and/or cleaning can often be done satisfactorily with an oxygen plasma. Apparatus and procedures used for this are described. Foils that were cleaned successfully, and some that were incompatible with the cleaning process are listed

  5. Photoresist removal using gaseous sulfur trioxide cleaning technology

    Science.gov (United States)

    Del Puppo, Helene; Bocian, Paul B.; Waleh, Ahmad

    1999-06-01

    A novel cleaning method for removing photoresists and organic polymers from semiconductor wafers is described. This non-plasma method uses anhydrous sulfur trioxide gas in a two-step process, during which, the substrate is first exposed to SO3 vapor at relatively low temperatures and then is rinsed with de-ionized water. The process is radically different from conventional plasma-ashing methods in that the photoresist is not etched or removed during the exposure to SO3. Rather, the removal of the modified photoresist takes place during the subsequent DI-water rinse step. The SO3 process completely removes photoresist and polymer residues in many post-etch applications. Additional advantages of the process are absence of halogen gases and elimination of the need for other solvents and wet chemicals. The process also enjoys a very low cost of ownership and has minimal environmental impact. The SEM and SIMS surface analysis results are presented to show the effectiveness of gaseous SO3 process after polysilicon, metal an oxide etch applications. The effects of both chlorine- and fluorine-based plasma chemistries on resist removal are described.

  6. Investigation of some cleaning surface treatments for the fabrication of ITER first wall panels by HIP

    Energy Technology Data Exchange (ETDEWEB)

    Frayssines, P.E.; Bucci, P. [CEA Grenoble (DRT/LITEN/DTH), 38 (France); Vito, E. de [CEA Grenoble (LITEN/DTH/LCPEM), 38 (France); Lorenzetto, P. [2EFDA, Garching (Germany)

    2007-07-01

    Full text of publication follows: ITER First Wall (FW) panels are the innermost part of the ITER reactor. Metallic materials used for their manufacture are 316L(N)-IG stainless steel, a copper alloy and beryllium. Stainless steel material is a support structure for the copper alloy that serves as a heat sink material and also for the beryllium tiles that are a protective armour against the plasma. All these materials are bonded together by Hot Isostatic Pressing (HIP). Thus, several types of joints (Cu/Cu, Cu/SS, SS/SS or Cu/Be) are present in a FW panels. Their manufacturing requires a very strict and advanced metallic surface preparation in order to eliminate most of the organic or oxide layers that could prevent the diffusion process between the facing materials. In this field, our laboratory practice enables to obtain sufficiently clean metallic surfaces and high strength joints are obtained when small mockups are made. However, the manufacture of a large number of FW panels in the future requires to find a new cleaning process that is industrially relevant without a strong reduction of the joint's mechanical properties. In this paper we present our investigations to find an industrial solution to clean efficiently copper alloy and stainless steel materials in order to manufacture high strength Cu/Cu, SS/SS or Cu/SS joints. Products investigated are mainly acid liquids proposed by chemical Company and a more advanced technique that uses a plasma process. HIP joints are tested mechanically by making impact toughness and tensile measurements. Results obtained with these solutions are compared to those obtained in our Laboratory by using our own cleaning route. Moreover, XPS analyses are performed on small specimens that have been submitted to the same cleaning treatments in order to better understand the mechanical results of our specimens. (authors)

  7. Investigation of some cleaning surface treatments for the fabrication of ITER first wall panels by HIP

    International Nuclear Information System (INIS)

    Frayssines, P.E.; Bucci, P.; Vito, E. de; Lorenzetto, P.

    2007-01-01

    Full text of publication follows: ITER First Wall (FW) panels are the innermost part of the ITER reactor. Metallic materials used for their manufacture are 316L(N)-IG stainless steel, a copper alloy and beryllium. Stainless steel material is a support structure for the copper alloy that serves as a heat sink material and also for the beryllium tiles that are a protective armour against the plasma. All these materials are bonded together by Hot Isostatic Pressing (HIP). Thus, several types of joints (Cu/Cu, Cu/SS, SS/SS or Cu/Be) are present in a FW panels. Their manufacturing requires a very strict and advanced metallic surface preparation in order to eliminate most of the organic or oxide layers that could prevent the diffusion process between the facing materials. In this field, our laboratory practice enables to obtain sufficiently clean metallic surfaces and high strength joints are obtained when small mockups are made. However, the manufacture of a large number of FW panels in the future requires to find a new cleaning process that is industrially relevant without a strong reduction of the joint's mechanical properties. In this paper we present our investigations to find an industrial solution to clean efficiently copper alloy and stainless steel materials in order to manufacture high strength Cu/Cu, SS/SS or Cu/SS joints. Products investigated are mainly acid liquids proposed by chemical Company and a more advanced technique that uses a plasma process. HIP joints are tested mechanically by making impact toughness and tensile measurements. Results obtained with these solutions are compared to those obtained in our Laboratory by using our own cleaning route. Moreover, XPS analyses are performed on small specimens that have been submitted to the same cleaning treatments in order to better understand the mechanical results of our specimens. (authors)

  8. Effectiveness of HVAC duct cleaning procedures in improving indoor air quality.

    Science.gov (United States)

    Ahmad, I; Tansel, B; Mitrani, J D

    2001-12-01

    Indoor air quality has become one of the most serious environmental concerns as an average person spends about 22 hr indoors on a daily basis. The study reported in this article, was conducted to determine the effectiveness of three commercial HVAC (Heating Ventilation Air Conditioning) duct cleaning processes in reducing the level of airborne particulate matter and viable bioaerosols. The three HVAC sanitation processes were: (1) Contact method (use of conventional vacuum cleaning of interior duct surfaces); (2) Air sweep method (use of compressed air to dislodging dirt and debris); (3) Rotary brush method (insertion of a rotary brush into the ductwork to agitate and dislodge the debris). Effectiveness of these sanitation processes was evaluated in terms of airborne particulate and viable bioaerosol concentrations in residential homes. Eight identical homes were selected in the same neighborhood. Two homes were cleaned using each procedure and two were used as controls. It was found that both particle count readings and bioaerosol concentrations were higher when cleaning was being performed than before or after cleaning, which suggests that dirt, debris and other pollutants may become airborne as a result of disturbances caused by the cleaning processes. Particle count readings at 0.3 micron size were found to have increased due to cigarette smoking. Particle counts at 1.0 micron size were reduced due to HVAC duct cleaning. Post-level bioaerosol concentrations, taken two days after cleaning, were found to be lower than the pre-level concentrations suggesting that the cleaning procedures were effective to some extent. Homes cleaned with the Air Sweep procedure showed the highest degree of reduction in bioaerosol concentration among the three procedures investigated.

  9. Cleaning of liquid LLW from decontamination processes using semipermeable membranes

    International Nuclear Information System (INIS)

    Dulama, M.; Deneanu, N.; Pavelescu, M.

    2003-01-01

    Of the three processes, which have been used extensively for liquid radioactive waste purification, evaporation and ion exchange are costly and flocculation gives a low degree of purification. By comparison to that, reverse osmosis offers intermediate purification at reasonable cost. Present research is examining the potential of using a membrane filtration system for the removal of dissolved radionuclides, but chemical treatment showed as necessary to convert soluble radionuclides, organic traces and metals to insoluble, filterable species. Liquid wastes within a CANDU station are segregated into normal and low-activity waste streams. The normal-activity waste includes wastes from the laboratories, laundries, some service-building drains, upgrade drains, and decontamination center. The drains from the reactor building, the heavy-water area, the spent-fuel pool, and the resin storage area are also directed to this normal activity wastes from showers and building drains in areas of the service building that would not normally be contaminated. The aqueous liquid wastes from the decontamination center and the other collected wastes from the chemical drain system are currently treated by the membrane plant. Generally, the liquid waste streams are effectively volume-reduced by a combination of continuous crossflow microfiltration (MF), spiral wound reverse osmosis (SWRO) and tubular reverse osmosis membrane technologies. Backwash chemical cleaning wastes from the membrane plant are further volume-reduced by evaporation. The concentrate from the membrane plant is ultimately immobilized with bitumen. The ability of the MF/SWRO technology to remove impurities non-selectively makes it suitable for the treatment of radioactive effluents from operating nuclear plants, with proper membrane selection, feed characterization, system configuration and system chemistry control. The choice of polysulfonate material for membrane was based on the high flow rates achievable with this

  10. Stereodynamics: From elementary processes to macroscopic chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Toshio [Department of Chemistry, National Taiwan University, Taipei 106, Taiwan (China); Graduate School of Science, Department of Chemistry, Osaka University, Toyonaka, 560-0043 Osaka (Japan); Che, Dock-Chil [Graduate School of Science, Department of Chemistry, Osaka University, Toyonaka, 560-0043 Osaka (Japan); Tsai, Po-Yu [Department of Chemistry, National Taiwan University, Taipei 106, Taiwan (China); Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Lin, King-Chuen [Department of Chemistry, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Palazzetti, Federico [Scuola Normale Superiore, Pisa (Italy); Dipartimento di Chimica Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Aquilanti, Vincenzo [Dipartimento di Chimica Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Roma (Italy); Instituto de Fisica, Universidade Federal da Bahia, Salvador (Brazil)

    2015-12-31

    This paper aims at discussing new facets on stereodynamical behaviors in chemical reactions, i.e. the effects of molecular orientation and alignment on reactive processes. Further topics on macroscopic processes involving deviations from Arrhenius behavior in the temperature dependence of chemical reactions and chirality effects in collisions are also discussed.

  11. Nanomaterials for the cleaning and pH adjustment of vegetable-tanned leather

    Science.gov (United States)

    Baglioni, Michele; Bartoletti, Angelica; Bozec, Laurent; Chelazzi, David; Giorgi, Rodorico; Odlyha, Marianne; Pianorsi, Diletta; Poggi, Giovanna; Baglioni, Piero

    2016-02-01

    Leather artifacts in historical collections and archives are often contaminated by physical changes such as soiling, which alter their appearance and readability, and by chemical changes which occur on aging and give rise to excessive proportion of acids that promote hydrolysis of collagen, eventually leading to gelatinization and loss of mechanical properties. However, both cleaning and pH adjustment of vegetable-tanned leather pose a great challenge for conservators, owing to the sensitivity of these materials to the action of solvents, especially water-based formulations and alkaline chemicals. In this study, the cleaning of historical leather samples was optimized by confining an oil-in-water nanostructured fluid in a highly retentive chemical hydrogel, which allows the controlled release of the cleaning fluid on sensitive surfaces. The chemical gel exhibits optimal viscoelasticity, which facilitates its removal after the application without leaving residues on the object. Nanoparticles of calcium hydroxide and lactate, dispersed in 2-propanol, were used to adjust the pH up to the natural value of leather, preventing too high alkalinity which causes swelling of fibers and denaturation of the collagen. The treated samples were characterized using scanning electron microscopy, controlled environment dynamic mechanical analysis, and infrared spectroscopy. The analytical assessment validated the use of tools derived from colloid and materials science for the preservation of collagen-based artifacts.

  12. Reflow process stabilization by chemical characteristics and process conditions

    Science.gov (United States)

    Kim, Myoung-Soo; Park, Jeong-Hyun; Kim, Hak-Joon; Kim, Il-Hyung; Jeon, Jae-Ha; Gil, Myung-Goon; Kim, Bong-Ho

    2002-07-01

    With the shrunken device rule below 130nm, the patterning of smaller contact hole with enough process margin is required for mass production. Therefore, shrinking technology using thermal reflow process has been applied for smaller contact hole formation. In this paper, we have investigated the effects of chemical characteristics such as molecular weight, blocking ratio of resin, cross-linker amount and solvent type with its composition to reflow process of resist and found the optimized chemical composition for reflow process applicable condition. And several process conditions like resist coating thickness and multi-step thermal reflow method have been also evaluated to stabilize the pattern profile and improve CD uniformity after reflow process. From the experiment results, it was confirmed that the effect of crosslinker in resist to reflow properties such as reflow temperature and reflow rate were very critical and it controlled the pattern profile during reflow processing. And also, it showed stable CD uniformity and improved resist properties for top loss, film shrinkage and etch selectivity. The application of lower coating thickness of resist induced symmetric pattern profile even at edge with wider process margin. The introduction of two-step baking method for reflow process showed uniform CD value, also. It is believed that the application of resist containing crosslinker and optimized process conditions for smaller contact hole patterning is necessary for the mass production with a design rule below 130nm.

  13. RECOGNITION OF MAIN PROCESSES FORMING CHEMICAL COMPOSITION OF THE SUPRAŚL RIVER WATER

    Directory of Open Access Journals (Sweden)

    Mirosław Skorbiłowicz

    2016-01-01

    Full Text Available The aim of the study was to identify and define the processes that affect the variability of the chemical composition of Supraśl river water at selected measuring points. One of the recognized multivariate statistical methods was used for identification. The research area covered the Suprasl river. Four measuring points were selected on the river – Michałowo, Gródek, Nowodworce, Dzikie. The measuring points were selected in such a way to take into account the impact of the most intense interaction located along the river. Changes in concentration were determined on the basis of monthly analyzes of water samples collected from the Supraśl river in 2003–2012 by the Regional Inspectorate for Environmental Protection (RIEP in Białystok. The analyses were performed in the RIEP laboratory in Bialystok, which has implemented and maintained a management system that meets the requirements of the norm PN-EN ISO/IEC 17025 + Ap.1:2007 approved by the certificate AB 165. The water samples were subject to determinations of dissolved oxygen concentration, BOD5, CODMn, CODCr, NH3, N-NH4+, NKieldahl, NO3-, N-NO3-, NO2-, N-NO2-, Ntot., PO43-, Ptot and electrical conductivity value. The monthly sum of precipitation was read based on data from the Weather Service “IMGW-PIB Monitor”. The research and analysis results allowed to identify the self-cleaning, nitrification, and de-nitrification processes, as well as enrichment affecting the variability of the chemical composition of the Supraśl river water. The results from the factor analysis showed some prevailing of enrichment processes over internal changes in the aquatic environment of the Supraśl river.

  14. Process Security in Chemical Engineering Education

    Science.gov (United States)

    Piluso, Cristina; Uygun, Korkut; Huang, Yinlun; Lou, Helen H.

    2005-01-01

    The threats of terrorism have greatly alerted the chemical process industries to assure plant security at all levels: infrastructure-improvement-focused physical security, information-protection-focused cyber security, and design-and-operation-improvement-focused process security. While developing effective plant security methods and technologies…

  15. Cellulose Acetate Replica Cleaning Study of Genesis Non-Flight Sample 3CZ00327

    Science.gov (United States)

    Kuhlman, K. R.; Schmeling, M.; Gonzalez, C. P.; Allton, J. H.; Burnett, D. S.

    2014-01-01

    The Genesis mission collected solar wind and brought it back to Earth in order to provide precise knowledge of solar isotopic and elemental compositions. The ions in the solar wind were stopped in the collectors at depths on the order of 10 to a few hundred nanometers. This shallow implantation layer is critical for scientific analysis of the composition of the solar wind and must be preserved throughout sample handling, cleaning, processing, distribution, preparation and analysis. We are working interactively with the community of scientists analyzing Genesis samples, using our unique laboratory facilities -- and, where needed, our unique cleaning techniques -- to significantly enhance the science return from the Genesis mission. This work is motivated by the need to understand the submicron contamination on the collectors in the Genesis payload as recovered from the crash site in the Utah desert, and -- perhaps more importantly -- how to remove it. That is, we are evaluating the effectiveness of the wet-chemical "cleaning" steps used by various investigators, to enable them to design improved methods of stripping terrestrial contamination from surfaces while still leaving the solar-wind signal intact.

  16. Next steps in the development of ecological soil clean-up values for metals.

    Science.gov (United States)

    Wentsel, Randall; Fairbrother, Anne

    2014-07-01

    This special series in Integrated Environmental Assessment Management presents the results from 6 workgroups that were formed at the workshop on Ecological Soil Levels-Next Steps in the Development of Metal Clean-Up Values (17-21 September 2012, Sundance, Utah). This introductory article presents an overview of the issues assessors face when conducting risk assessments for metals in soils, key US Environmental Protection Agency (USEPA) documents on metals risk assessment, and discusses the importance of leveraging from recent major terrestrial research projects, primarily to address Registration, Evaluation, Authorization and Restriction of Chemical Substances (REACH) requirements in Europe, that have significantly advanced our understanding of the behavior and toxicity of metals in soils. These projects developed large data sets that are useful for the risk assessment of metals in soil environments. The workshop attendees met to work toward developing a process for establishing ecological soil clean-up values (Eco-SCVs). The goal of the workshop was to progress from ecological soil screening values (Eco-SSLs) to final clean-up values by providing regulators with the methods and processes to incorporate bioavailability, normalize toxicity thresholds, address food-web issues, and incorporate background concentrations. The REACH data sets were used by workshop participants as case studies in the development of the ecological standards for soils. The workshop attendees discussed scientific advancements in bioavailability, soil biota and wildlife case studies, soil processes, and food-chain modeling. In addition, one of the workgroups discussed the processes needed to frame the topics to gain regulatory acceptance as a directive or guidance by Canada, the USEPA, or the United States. © 2013 SETAC.

  17. Replacement Technologies for Precision Cleaning of Aerospace Hardware for Propellant Service

    Science.gov (United States)

    Beeson, Harold; Kirsch, Mike; Hornung, Steven; Biesinger, Paul

    1997-01-01

    The NASA White Sands Test Facility (WSTF) is developing cleaning and verification processes to replace currently used chlorofluorocarbon-l13- (CFC-113-) based processes. The processes being evaluated include both aqueous- and solvent-based techniques. Replacement technologies are being investigated for aerospace hardware and for gauges and instrumentation. This paper includes the findings of investigations of aqueous cleaning and verification of aerospace hardware using known contaminants, such as hydraulic fluid and commonly used oils. The results correlate nonvolatile residue with CFC 113. The studies also include enhancements to aqueous sampling for organic and particulate contamination. Although aqueous alternatives have been identified for several processes, a need still exists for nonaqueous solvent cleaning, such as the cleaning and cleanliness verification of gauges used for oxygen service. The cleaning effectiveness of tetrachloroethylene (PCE), trichloroethylene (TCE), ethanol, hydrochlorofluorocarbon 225 (HCFC 225), HCFC 141b, HFE 7100(R), and Vertrel MCA(R) was evaluated using aerospace gauges and precision instruments and then compared to the cleaning effectiveness of CFC 113. Solvents considered for use in oxygen systems were also tested for oxygen compatibility using high-pressure oxygen autogenous ignition and liquid oxygen mechanical impact testing.

  18. Optimized high temperature oxidation and cleaning at Bugey 3

    International Nuclear Information System (INIS)

    Ranchoux, Gilles; Wintergerst, Matthieu; Bachet, Martin; Leclercq, Stephanie; Duron, Jean-Daniel; Meunier, Jean-Pierre; Blond, Serge; Dacquait Frederic

    2012-09-01

    As a part of the EDF Source Term Reduction project, an experimental procedure was carried out at Bugey 3 further to the steam generator replacement. This innovative procedure consists in theory in two complementary phases /1/: - Phase 1: a SG tubes optimized oxidation performed during pre-critical hot functional tests (basic and reducing chemistry) aims to generate an as protective as possible inner oxide layer allowing to reduce the later nickel release, - Phase 2: a cleaning procedure of the primary circuit performed under acid and reducing chemical conditioning at 170 deg. C intends to dissolve and eliminate the outer oxide layer by a simultaneous purification. The objective of such a procedure is to reduce corrosion products inventory (mainly nickel) generated by the first SG tube oxidation during hot functional tests and first operation months by carrying out an appropriate cleaning procedure. Gains were expected not only on RCS and auxiliary systems contamination, dose rates and thus collective dose but also on next outages duration. The objective of this paper is to describe the process implementation at Bugey 3: effective procedure put in place, monitoring program (chemistry and dose rate measurements, EMECC campaign) and firsts results. (authors)

  19. Quality Assessment of Film Processing Chemicals in Dentistry

    International Nuclear Information System (INIS)

    Han, Mi Ra; Kang, Byung Chul

    1999-01-01

    The purpose of this study was to compare the qualities of the four different processing chemicals (solutions). With EP 21 films (Ektaspeed plus film, Kodak Co., USA), nine unexposed and nine exposed films of a step wedge were processed utilizing automatic film processor (XR 24, Durr Co., Germany) for 5 days. During 5 days, the total number of processed films including out-patient's intraoral films were about 400-500 for each brand. Base plus fog density, film density, contrast of processed films were measured with densitometer (model 07-443 digital densitometer, Victoreen Co., USA). These measurements were analyzed for comparison. The results were as follows,1. For the base plus fog density, there was significant difference among the four chemicals (p<0.05). The sequence of the base plus fog densities was in ascending order by Kodak, X-dol 90, Agfa and Konica. 2. For the film density, all chemicals showed useful range of photographic densities (0.25-2.5). The sequence of the film densities was in ascending order by Kodak, X-dol 90, Konica and Agfa. But there was no statistically significant difference of film density between X-dol and Kodak (p<0.05). 3. The sequence of the contrasts was in ascending order by Konica, X-dol 90, Kodak and Agfa. But there was no statistically significant difference of contrast between X-dol and Konica (p<0.05). These results indicated that the four processing chemicals had the clinically useful film density and contrast, but only Kodak processing chemical had useful base plus fog density.

  20. Cleaning power and abrasivity of European toothpastes.

    Science.gov (United States)

    Wülknitz, P

    1997-11-01

    For 41 toothpastes available to European consumers in 1995, the cleaning efficacy was evaluated in comparison with abrasivity on dentin (RDA value). For cleaning power assessment, a modified pellicle cleaning ratio (PCR) measurement method was developed. The method is characterized by a five-day tea-staining procedure on bovine front teeth slabs on a rotating wheel, standardized brushing of the slabs in a V8 cross-brushing machine, and brightness measurement by a chromametric technique. All tested products were in accordance with the new DIN/ISO standard 11,609 for toothpastes in terms of dentin abrasivity. Not a single product exceeded an RDA value of 200. The majority of toothpastes (80%) had an RDA value below 100. Only three products surpassed the reference in cleaning power. Most products (73%) had a cleaning power (PCR value) between 20 and 80. The correlation between cleaning power and dentin abrasion was low (r = 0.66), which can be explained with the different influence on dentin and stains by factors like abrasive type, particle surface and size, as well as the chemical influence of other toothpaste ingredients. Some major trends could be shown on the basis of abrasive types. The ratio PCR to RDA was rather good in most silica-based toothpastes. A lower ratio was found in some products containing calcium carbonate or aluminum trihydrate as the only abrasive. The addition of other abrasives, such as polishing alumina, showed improved cleaning power. Some active ingredients, especially sequenstrants such as sodium tripolyphosphate or AHBP, also improve the PCR/RDA ratio by stain-dissolving action without being abrasive. The data for some special anti-stain products did not differ significantly from standard products. Compared with data measured in 1988, a general trend toward reduced abrasivity without loss of cleaning efficacy could be noticed on the European toothpaste market. This may be mostly due to the increased use of high-performance abrasives such

  1. New trajectory-driven aerosol and chemical process model Chemical and Aerosol Lagrangian Model (CALM

    Directory of Open Access Journals (Sweden)

    P. Tunved

    2010-11-01

    Full Text Available A new Chemical and Aerosol Lagrangian Model (CALM has been developed and tested. The model incorporates all central aerosol dynamical processes, from nucleation, condensation, coagulation and deposition to cloud formation and in-cloud processing. The model is tested and evaluated against observations performed at the SMEAR II station located at Hyytiälä (61° 51' N, 24° 17' E over a time period of two years, 2000–2001. The model shows good agreement with measurements throughout most of the year, but fails in reproducing the aerosol properties during the winter season, resulting in poor agreement between model and measurements especially during December–January. Nevertheless, through the rest of the year both trends and magnitude of modal concentrations show good agreement with observation, as do the monthly average size distribution properties. The model is also shown to capture individual nucleation events to a certain degree. This indicates that nucleation largely is controlled by the availability of nucleating material (as prescribed by the [H2SO4], availability of condensing material (in this model 15% of primary reactions of monoterpenes (MT are assumed to produce low volatile species and the properties of the size distribution (more specifically, the condensation sink. This is further demonstrated by the fact that the model captures the annual trend in nuclei mode concentration. The model is also used, alongside sensitivity tests, to examine which processes dominate the aerosol size distribution physical properties. It is shown, in agreement with previous studies, that nucleation governs the number concentration during transport from clean areas. It is also shown that primary number emissions almost exclusively govern the CN concentration when air from Central Europe is advected north over Scandinavia. We also show that biogenic emissions have a large influence on the amount of potential CCN observed

  2. Plasma Cleaning

    Science.gov (United States)

    Hintze, Paul E.

    2016-01-01

    NASA's Kennedy Space Center has developed two solvent-free precision cleaning techniques: plasma cleaning and supercritical carbon dioxide (SCCO2), that has equal performance, cost parity, and no environmental liability, as compared to existing solvent cleaning methods.

  3. Clean technologies: methods for minimizing the releases and choice of the effluents valorization processes. Application to metal workshops; Technologies propres: methodes de minimisation des rejets et de choix des procedes de valorisation des effluents. Application aux ateliers de traitement de surface

    Energy Technology Data Exchange (ETDEWEB)

    Laforest, V.

    1999-12-10

    Currently, the essential part of the money invested by the industrialist is for the water treatment. In France, most of the 20 billions francs per year devoted to the water treatment is used for the industrial activity. The global management of effluents favour the integration of clean technologies (optimization, change and modification of the production process) in order to reduce the pollution problem at its source. Our study aims at the introduction of clean technologies in the metal workshops (consumer and generator of water and chemicals) by the development of two data management methods, which lead to two decision support systems. The aim of the first one is to minimize both the water consumption and the wastewater disposal by optimizing the production process (optimum yield and efficiency of the rinsing baths). The second one concerns the choice of valorization techniques considering the valorization objectives, the effluents characteristics and the parameters limiting the use of the techniques. Our approach fits into a global management method for the metal finishing industry wastewater. Its aim is to limit the quantity of wastewater generated, to valorize effluents and by this way to develop the clean technologies.

  4. 75 FR 29605 - Clean Alternative Fuel Vehicle and Engine Conversions

    Science.gov (United States)

    2010-05-26

    ... Part II Environmental Protection Agency 40 CFR Parts 85 and 86 Clean Alternative Fuel Vehicle and...-0299; FRL-9149-9] RIN 2060-AP64 Clean Alternative Fuel Vehicle and Engine Conversions AGENCY... streamline the process by which manufacturers of clean alternative fuel conversion systems may demonstrate...

  5. 40 CFR 52.246 - Control of dry cleaning solvent vapor losses.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control of dry cleaning solvent vapor... cleaning solvent vapor losses. (a) For the purpose of this section, “dry cleaning operation” means that process by which an organic solvent is used in the commercial cleaning of garments and other fabric...

  6. CPICOR{trademark}: Clean power from integrated coal-ore reduction

    Energy Technology Data Exchange (ETDEWEB)

    Wintrell, R.; Miller, R.N.; Harbison, E.J.; LeFevre, M.O.; England, K.S.

    1997-12-31

    The US steel industry, in order to maintain its basic iron production, is thus moving to lower coke requirements and to the cokeless or direct production of iron. The US Department of Energy (DOE), in its Clean Coal Technology programs, has encouraged the move to new coal-based technology. The steel industry, in its search for alternative direct iron processes, has been limited to a single process, COREX{reg_sign}. The COREX{reg_sign} process, though offering commercial and environmental acceptance, produces a copious volume of offgas which must be effectively utilized to ensure an economical process. This volume, which normally exceeds the internal needs of a single steel company, offers a highly acceptable fuel for power generation. The utility companies seeking to offset future natural gas cost increases are interested in this clean fuel. The COREX{reg_sign} smelting process, when integrated with a combined cycle power generation facility (CCPG) and a cryogenic air separation unit (ASU), is an outstanding example of a new generation of environmentally compatible and highly energy efficient Clean Coal Technologies. This combination of highly integrated electric power and hot metal coproduction, has been designated CPICOR{trademark}, Clean Power from Integrated Coal/Ore Reduction.

  7. Process Design and Evaluation for Chemicals Based on Renewable Resources

    DEFF Research Database (Denmark)

    Fu, Wenjing

    . In addition, another characteristic of chemicals based on renewable feedstocks is that many alternative technologies and possible routes exist, resulting in many possible process flowsheets. The challenge for process engineers is then to choose between possible process routes and alternative technologies...... development of chemicals based on renewable feedstocks. As an example, this thesis especially focuses on applying the methodology in process design and evaluation of the synthesis of 5-hydroxymethylfurfural (HMF) from the renewable feedstock glucose/fructose. The selected example is part of the chemoenzymatic......One of the key steps in process design is choosing between alternative technologies, especially for processes producing bulk and commodity chemicals. Recently, driven by the increasing oil prices and diminishing reserves, the production of bulk and commodity chemicals from renewable feedstocks has...

  8. Megasonic cleaning strategy for sub-10nm photomasks

    Science.gov (United States)

    Hsu, Jyh-Wei; Samayoa, Martin; Dress, Peter; Dietze, Uwe; Ma, Ai-Jay; Lin, Chia-Shih; Lai, Rick; Chang, Peter; Tuo, Laurent

    2016-10-01

    One of the main challenges in photomask cleaning is balancing particle removal efficiency (PRE) with pattern damage control. To overcome this challenge, a high frequency megasonic cleaning strategy is implemented. Apart from megasonic frequency and power, photomask surface conditioning also influences cleaning performance. With improved wettability, cleanliness is enhanced while pattern damage risk is simultaneously reduced. Therefore, a particle removal process based on higher megasonic frequencies, combined with proper surface pre-treatment, provides improved cleanliness without the unintended side effects of pattern damage, thus supporting the extension of megasonic cleaning technology into 10nm half pitch (hp) device node and beyond.

  9. Financing clean energy market creation. Clean energy ventures, venture capitalists and other investors

    Energy Technology Data Exchange (ETDEWEB)

    Teppo, T. [Helsinki Univ. of Technology, Espoo (Finland). Development and Management in Industry

    2006-07-01

    , technology, regulatory control, and exits. The four cognitive risk factors were investment outcome history, VC risk preferences, investment domain familiarity, and venture framing. Third, the study developed a model showing that parent firm organizational culture affects the performance of a CVC fund. The effect of the organizational culture is moderated by risk-taking practices in the parent firm's decision-making process and the parent firm's skills in managing, measuring, and compensating fund success. The main contribution of this dissertation is in identifying theoretical models that explain the clean energy venture entrepreneurial challenges, how VCs view clean energy ventures from a risk perspective, and how the organizational culture of a firm affects its CVC activity. The findings of the study suggest several managerial implications to policy makers, corporations planning to launch CVC fund activities, venture capitalists, and clean energy ventures. The findings and limitations of the study suggest several avenues for future research. First of all, the developed models and propositions should be quantitatively tested and further refined. Furthermore, the effect of the parent firm's organizational culture on the CVC fund performance warrants further investigation, preferably in some other than clean energy context. In addition, future research could explore the two other clean energy venture entrepreneurial challenges, growth management and market education, in more detail. The role of institutions and energy policy in the formation of clean energy markets, especially from the perspective of clean energy ventures and investors, would also be worth exploring in future research. (orig.)

  10. Method of manipulating the chemical properties of water to improve the effectiveness of a desired process

    Science.gov (United States)

    Hawthorne, Steven B.; Miller, David J.; Lagadec, Arnaud Jean-Marie; Hammond, Peter James; Clifford, Anthony Alan

    2002-01-01

    The method of the present invention is adapted to manipulate the chemical properties of water in order to improve the effectiveness of a desired process. The method involves heating the water in the vessel to subcritical temperatures between 100.degree. to 374.degree. C. while maintaining sufficient pressure to the water to maintain the water in the liquid state. Various physiochemical properties of the water can be manipulated including polarity, solute solubility, surface tension, viscosity, and the disassociation constant. The method of the present invention has various uses including extracting organics from solids and semisolids such as soil, selectively extracting desired organics from liquids, selectively separating organics using sorbent phases, enhancing reactions by controlling the disassociation constant of water, cleaning waste water, removing organics from water using activated carbon or other suitable sorbents, and degrading various compounds.

  11. Bench-scale testing of a micronized magnetite, fine-coal cleaning process

    Energy Technology Data Exchange (ETDEWEB)

    Suardini, P.J. [Custom Coals, International, Pittsburgh, PA (United States)

    1995-11-01

    Custom Coals, International has installed and is presently testing a 500 lb/hr. micronized-magnetite, fine-coal cleaning circuit at PETC`s Process Research Facility (PRF). The cost-shared project was awarded as part of the Coal Preparation Program`s, High Efficiency Preparation Subprogram. The project includes design, construction, testing, and decommissioning of a fully-integrated, bench-scale circuit, complete with feed coal classification to remove the minus 30 micron slimes, dense medium cycloning of the 300 by 30 micron feed coal using a nominal minus 10 micron size magnetite medium, and medium recovery using drain and rinse screens and various stages and types of magnetic separators. This paper describes the project circuit and goals, including a description of the current project status and the sources of coal and magnetite which are being tested.

  12. Ceramic membrane defouling (cleaning) by air Nano Bubbles.

    Science.gov (United States)

    Ghadimkhani, Aliasghar; Zhang, Wen; Marhaba, Taha

    2016-03-01

    Ceramic membranes are among the most promising technologies for membrane applications, owing to their excellent resistance to mechanical, chemical, and thermal stresses. However, membrane fouling is still an issue that hampers the applications at large scales. Air Nano Bubbles (NBs), due to high mass transfer efficiency, could potentially prevent fouling of ceramic membrane filtration processes. In this study, bench and pilot scale ceramic membrane filtration was performed with air NBs to resist fouling. To simulate fouling, humic acid, as an organic foulant, was applied to the membrane flat sheet surface. Complete membrane clogging was achieved in less than 6 h. Membrane defouling (cleaning) was performed by directly feeding of air NBs to the membrane cells. The surface of the ceramic membrane was superbly cleaned by air NBs, as revealed by atomic force microscope (AFM) images before and after the treatment. The permeate flux recovered to its initial level (e.g., 26.7 × 10(-9) m(3)/m(2)/s at applied pressure of 275.8 kPa), which indicated that NBs successfully unclogged the pores of the membrane. The integrated ceramic membrane and air NBs system holds potential as an innovative sustainable technology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Combustion and environmental performance of clean coal end products

    Energy Technology Data Exchange (ETDEWEB)

    Skodras, G.; Sakellaropoulos, G. [Centre for Research and Technology, Hellas, Ptolemaidas-Kozanis, Ptolemaida (Greece). Inst. for Solid Fuel Technolgy and Applications]|[Aristotle Univ. of Thessaloniki, Thessaloniki (Greece). Dept. of Chemical Engineering, Chemical Process Engineering Lab]|[Chemical Process Engineering Research Inst., Thessaloniki (Greece). Lab. of Solid Fuels and Environment; Someus, E. [Thermal Desorption Technology Group (Greece); Grammelis, P.; Amarantos, P.S. [Centre for Research and Technology, Hellas, Ptolemaidas-Kozanis, Ptolemaida (Greece). Inst. for Solid Fuel Technolgy and Applications; Palladas, A.; Basinas, P.; Natas, P.; Prokopidou, M.; Diamantopoulou, I.; Sakellaropoulos, G. [Aristotle Univ. of Thessaloniki, Thessaloniki (Greece). Dept. of Chemical Engineering, Chemical Process Engineering Lab

    2006-07-01

    Clean and affordable power production is needed in order to achieve sustainable economic development. This paper focused on clean coal technologies in which coal-fired power plants are used in conjunction with large amounts of renewable energy sources to offer a high level of process safety and long term management of all residual operation streams. Thermal Desorption Recycle-Reduce-Reuse Technology (TDT-3R) was described as being a promising solid fuel pretreatment process for clean energy production up to 300 MWe capacities. TDT-3R is based on low temperature carbonisation fuel pre-treatment principles, which produce cleansed anthracite type fuels from coal and other carbonaceous material such as biomass and organic wastes. The combustion efficiency of such clean coals and the environmental performance of the TDT-3R process were investigated in this study via pilot scale tests of clean fuel production. Tests included flue gas emissions monitoring, raw fuel and product characterisation and thermogravimetric tests, polychlorinated dibenzo-p-dioxins and dibenzo-furans, and heavy metals analyses, and toxicity tests. Raw material included coal and biomass, such as willow, straw and demolition wood. The fuels were heated in a rotary kiln operating at 550 degrees C under slightly vacuum conditions. Clean coals were tested either alone or in conjunction with biomass fuels in a pilot scale combustion facility at Dresden, Germany. The clean coal samples were shown to have higher fixed carbon and ash content and lower volatiles compared to the respective raw coal samples. The major advantage of the TDT-3R process is the production of fuels with much lower pollutants content. Low nitrogen, sulphur, chlorine and heavy metal contents result in produced fuels that have excellent environmental performance, allow boiler operation in higher temperatures and overall better efficiency. Moreover, the use of clean fuels reduces deposition problems in the combustion chamber due to the

  14. ALTERNATIVE AND ENHANCED CHEMICAL CLEANING: BASIC STUDIES RESULTS FY2010

    Energy Technology Data Exchange (ETDEWEB)

    King, W.; Hay, M.

    2011-01-24

    In an effort to develop and optimize chemical cleaning methods for the removal of sludge heels from High Level Waste tanks, solubility tests have been conducted using nonradioactive, pure metal phases. The metal phases studied included the aluminum phase gibbsite and the iron phases hematite, maghemite, goethite, lepidocrocite, magnetite, and wustite. Many of these mineral phases have been identified in radioactive, High Level Waste sludge at the Savannah River and Hanford Sites. Acids evaluated for dissolution included oxalic, nitric, and sulfuric acids and a variety of other complexing organic acids. The results of the solubility tests indicate that mixtures of oxalic acid with either nitric or sulfuric acid are the most effective cleaning solutions for the dissolution of the primary metal phases in sludge waste. Based on the results, optimized conditions for hematite dissolution in oxalic acid were selected using nitric or sulfuric acid as a supplemental proton source. Electrochemical corrosion studies were also conducted (reported separately; Wiersma, 2010) with oxalic/mineral acid mixtures to evaluate the effects of these solutions on waste tank integrity. The following specific conclusions can be drawn from the test results: (1) Oxalic acid was shown to be superior to all of the other organic acids evaluated in promoting the dissolution of the primary sludge phases. (2) All iron phases showed similar solubility trends in oxalic acid versus pH, with hematite exhibiting the lowest solubility and the slowest dissolution. (3) Greater than 90% hematite dissolution occurred in oxalic/nitric acid mixtures within one week for two hematite sources and within three weeks for a third hematite sample with a larger average particle size. This dissolution rate appears acceptable for waste tank cleaning applications. (4) Stoichiometric dissolution of iron phases in oxalic acid (based on the oxalate concentration) and the formation of the preferred 1:1 Fe to oxalate complex

  15. Using Phytoremediation to Clean Up Contamination at Military Installations

    International Nuclear Information System (INIS)

    Zellmer, S.D.; Hinchman, R.R.; Negri, M.C.; Schneider, J.F.; Gatliff, E.G.

    1997-07-01

    During and following World War II, wastes from the production of munitions and other military materials were disposed of using the best available practices acceptable at that time. However, these disposal methods often contaminated soil and groundwater with organic compounds and metals that require cleanup under current regulations. An emerging technology for cleaning contaminated soils and shallow groundwater is phytoremediation, an environmentally friendly, low- cost, and low-tech process. Phytoremediation encompasses all plant- influenced biological, chemical, and physical processes that aid in the uptake, degradation, and metabolism of contaminants by either plants or free-living organisms in the plant's rhizosphere. A phytoremediation system can be viewed as a biological, solar-driven, pump-and-treat system with an extensive, self-extending uptake network (the root system) that enhances the soil and below-ground ecosystem for subsequent productive use. Argonne National Laboratory (ANL) has been conducting basic and applied research in phytoremediation since 1990. Initial greenhouse studies evaluated salt-tolerant wetland plants to clean UP and reduce the volume of salty 'produced water' from petroleum wells. Results of these studies were used to design a bioreactor for processing produced water that is being demonstrated at a natural gas well in Oklahoma; this system can reduce produced water volume by about 75% in less than eight days, representing substantial savings in waste disposal cost. During 1994, ANL conducted a TNT plant uptake and in situ remediation study in a ridge-and-furrow area used for the disposal of pink water at the Joliet Army Ammunition Plant

  16. Using Phytoremediation to Clean Up Contamination at Military Installations

    Energy Technology Data Exchange (ETDEWEB)

    Zellmer, S.D.; Hinchman, R.R.; Negri, M.C.; Schneider, J.F. [Argonne National Lab., IL (United States); Gatliff, E.G. [Applied Natural Sciences, Inc., Fairfield, OH (United States)

    1997-07-01

    During and following World War II, wastes from the production of munitions and other military materials were disposed of using the best available practices acceptable at that time. However, these disposal methods often contaminated soil and groundwater with organic compounds and metals that require cleanup under current regulations. An emerging technology for cleaning contaminated soils and shallow groundwater is phytoremediation, an environmentally friendly, low- cost, and low-tech process. Phytoremediation encompasses all plant- influenced biological, chemical, and physical processes that aid in the uptake, degradation, and metabolism of contaminants by either plants or free-living organisms in the plant`s rhizosphere. A phytoremediation system can be viewed as a biological, solar-driven, pump-and-treat system with an extensive, self-extending uptake network (the root system) that enhances the soil and below-ground ecosystem for subsequent productive use. Argonne National Laboratory (ANL) has been conducting basic and applied research in phytoremediation since 1990. Initial greenhouse studies evaluated salt-tolerant wetland plants to clean UP and reduce the volume of salty `produced water` from petroleum wells. Results of these studies were used to design a bioreactor for processing produced water that is being demonstrated at a natural gas well in Oklahoma; this system can reduce produced water volume by about 75% in less than eight days, representing substantial savings in waste disposal cost. During 1994, ANL conducted a TNT plant uptake and in situ remediation study in a ridge-and-furrow area used for the disposal of pink water at the Joliet Army Ammunition Plant.

  17. Environmentally benign chemical synthesis and processing

    International Nuclear Information System (INIS)

    Hancock, K.G.

    1992-01-01

    A new era of university-industry-government partnership is required to address the intertwined problems of industrial economic competitiveness and environmental quality. Chemicals that go up the stacks and down the drains are simultaneously a serious detriment to the environment, a waste of natural resources, and a threat to industrial profitability. Recently, the NSF Divisions of Chemistry and chemical and Thermal Systems have joined with the Council for Chemical research in a new grant program to reduce pollution at the source by underwriting research aimed at environmentally benign chemical synthesis and processing. Part of a broader NSF initiative on environmental science research, this new program serves as a model for university-industry-government joint action and technology transfer. Other features of this program and related activities will be described in this paper

  18. Energy conversion technology by chemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Oh, I W; Yoon, K S; Cho, B W [Korea Inst. of Science and Technology, Seoul (Korea, Republic of); and others

    1996-12-01

    The sharp increase in energy usage according to the industry development has resulted in deficiency of energy resources and severe pollution problems. Therefore, development of the effective way of energy usage and energy resources of low pollution is needed. Development of the energy conversion technology by chemical processes is also indispensable, which will replace the pollutant-producing and inefficient mechanical energy conversion technologies. Energy conversion technology by chemical processes directly converts chemical energy to electrical one, or converts heat energy to chemical one followed by heat storage. The technology includes batteries, fuel cells, and energy storage system. The are still many problems on performance, safety, and manufacturing of the secondary battery which is highly demanded in electronics, communication, and computer industries. To overcome these problems, key components such as carbon electrode, metal oxide electrode, and solid polymer electrolyte are developed in this study, followed by the fabrication of the lithium secondary battery. Polymer electrolyte fuel cell, as an advanced power generating apparatus with high efficiency, no pollution, and no noise, has many applications such as zero-emission vehicles, on-site power plants, and military purposes. After fabricating the cell components and operating the single cells, the fundamental technologies in polymer electrolyte fuel cell are established in this study. Energy storage technology provides the safe and regular heat energy, irrespective of the change of the heat energy sources, adjusts time gap between consumption and supply, and upgrades and concentrates low grade heat energy. In this study, useful chemical reactions for efficient storage and transport are investigated and the chemical heat storage technology are developed. (author) 41 refs., 90 figs., 20 tabs.

  19. Clean Coal Diesel Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Robert Wilson

    2006-10-31

    A Clean Coal Diesel project was undertaken to demonstrate a new Clean Coal Technology that offers technical, economic and environmental advantages over conventional power generating methods. This innovative technology (developed to the prototype stage in an earlier DOE project completed in 1992) enables utilization of pre-processed clean coal fuel in large-bore, medium-speed, diesel engines. The diesel engines are conventional modern engines in many respects, except they are specially fitted with hardened parts to be compatible with the traces of abrasive ash in the coal-slurry fuel. Industrial and Municipal power generating applications in the 10 to 100 megawatt size range are the target applications. There are hundreds of such reciprocating engine power-plants operating throughout the world today on natural gas and/or heavy fuel oil.

  20. Application to cleaning of waste plastic surfaces using atmospheric non-thermal plasma jets

    Energy Technology Data Exchange (ETDEWEB)

    Araya, Masayuki [Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan); Yuji, Toshifumi [Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8550 (Japan)]. E-mail: t-yuji@hiroshima-cmt.ac.jp; Watanabe, Takayuki [Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan); Kashihara, Junzou [SHARP corporation, 1-9-2 Nakase, Mihama-Ku, Chiba 261-8520 (Japan); Sumida, Yoshitake [SHARP corporation, 2613-1 Ichinomoto-cho, Tenri 632-8567 (Japan)

    2007-03-12

    The removal of paint on the surface of waste plastics is difficult by the conventional process; in this research, a new cleaning mechanism using atmospheric plasmas was examined through optical emission spectroscopy, electron spectroscopy for chemical analysis, and scanning electron microscopy. Results indicate that an increase of pulse frequency enables for a short processing time for the removal of the paint film, signifying that the production of radicals in plasma, especially oxygen radicals, can be controlled by pulse frequency. Plasma jets were generated under the experimental conditions of an input power of 250 W to 400 W, a pulse frequency of 2 kHz to 12 kHz, and a plasma gas flow rate of 30 L/min. Examination of the intensity ratio of the reactive species, as measured by emission spectroscopy, showed that the O/N value increased with an increase in pulse frequency. Results of analysis with electron spectroscopy for chemical analysis show that nitrogen atoms and molybdenum in only the paint film decreased through plasma processing.

  1. Application to cleaning of waste plastic surfaces using atmospheric non-thermal plasma jets

    International Nuclear Information System (INIS)

    Araya, Masayuki; Yuji, Toshifumi; Watanabe, Takayuki; Kashihara, Junzou; Sumida, Yoshitake

    2007-01-01

    The removal of paint on the surface of waste plastics is difficult by the conventional process; in this research, a new cleaning mechanism using atmospheric plasmas was examined through optical emission spectroscopy, electron spectroscopy for chemical analysis, and scanning electron microscopy. Results indicate that an increase of pulse frequency enables for a short processing time for the removal of the paint film, signifying that the production of radicals in plasma, especially oxygen radicals, can be controlled by pulse frequency. Plasma jets were generated under the experimental conditions of an input power of 250 W to 400 W, a pulse frequency of 2 kHz to 12 kHz, and a plasma gas flow rate of 30 L/min. Examination of the intensity ratio of the reactive species, as measured by emission spectroscopy, showed that the O/N value increased with an increase in pulse frequency. Results of analysis with electron spectroscopy for chemical analysis show that nitrogen atoms and molybdenum in only the paint film decreased through plasma processing

  2. Study on surface properties of gilt-bronze artifacts, after Nd:YAG laser cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeyoun [Division of Restoration Technology, National Research Institute of Cultural Heritage, Daejeon (Korea, Republic of); Cho, Namchul, E-mail: nam1611@hanmail.net [Department of Cultural Heritage Conservation Science, Kongju National University, Gongju, 314-701 (Korea, Republic of); Lee, Jongmyoung [Laser Engineering Group, IMT Co. Ltd, Gyeonggi (Korea, Republic of)

    2013-11-01

    As numerous pores are formed at plating gilt-bronze artifacts, the metal underlying the gold is corroded and corrosion products are formed on layer of gold. Through this study, the surfaces of gilt-bronze are being investigated before and after the laser irradiation to remove corrosion products of copper by using Nd:YAG laser. For gilt-bronze specimens, laser and chemical cleaning were performed, and thereafter, surface analysis with SEM-EDS, AFM, and XPS were used to determine the surface characteristics. Experimental results show that chemical cleaning removes corrosion products of copper through dissolution but it was not removed uniformly and separated the metal substrate and the gold layer. Nevertheless, through laser cleaning, some of the corrosions were removed with some damaged areas due to certain conditions and brown residues remained. Brown residues were copper corrosion products mixed with soil left within the gilt layer. It was due to surface morphology of uneven and rough gilt layer. Hence, they did not react effectively to laser beams, and thus, remained as residues. The surface properties of gilt-bronze should be thoroughly investigated with various surface analyses to succeed in laser cleaning without damages or residues.

  3. The removal of mercury from solid mixed waste using chemical leaching processes

    International Nuclear Information System (INIS)

    Gates, D.D.; Chao, K.K.; Cameron, P.A.

    1995-07-01

    The focus of this research was to evaluate chemical leaching as a technique to treat soils, sediments, and glass contaminated with either elemental mercury or a combination of several mercury species. Potassium iodide/iodine solutions were investigated as chemical leaching agents for contaminated soils and sediments. Clean, synthetic soil material and surrogate storm sewer sediments contaminated with mercury were treated with KI/I 2 solutions. It was observed that these leaching solutions could reduce the mercury concentration in soil and sediments by 99.8%. Evaluation of selected posttreatment sediment samples revealed that leachable mercury levels in the treated solids exceeded RCRA requirements. The results of these studies suggest that KI/I 2 leaching is a treatment process that can be used to remove large quantities of mercury from contaminated soils and sediments and may be the only treatment required if treatment goals are established on Hg residual concentrations in solid matrices. Fluorescent bulbs were used to simulate mercury contaminated glass mixed waste. To achieve mercury contamination levels similar to those found in larger bulbs such as those used in DOE facilities a small amount of Hg was added to the crushed bulbs. The most effective agents for leaching mercury from the crushed fluorescent bulbs were KI/I 2 , NaOCl, and NaBr + acid. Radionuclide surrogates were added to both the EPA synthetic soil material and the crushed fluorescent bulbs to determine the fate of radionuclides following chemical leaching with the leaching agents determined to be the most promising. These experiments revealed that although over 98% of the dosed mercury solubilized and was found in the leaching solution, no Cerium was measured in the posttreatment leaching solution. This finding suggest that Uranium, for which Ce was used as a surrogate, would not solubilize during leaching of mercury contaminated soil or glass

  4. Criticality concerns in cleaning large uranium hexafluoride cylinders

    International Nuclear Information System (INIS)

    Sheaffer, M.K.; Keeton, S.C.; Lutz, H.F.

    1995-06-01

    Cleaning large cylinders used to transport low-enriched uranium hexafluoride (UF 6 ) presents several challenges to nuclear criticality safety. This paper presents a brief overview of the cleaning process, the criticality controls typically employed and their bases. Potential shortfalls in implementing these controls are highlighted, and a simple example to illustrate the difficulties in complying with the Double Contingency Principle is discussed. Finally, a summary of recommended criticality controls for large cylinder cleaning operations is presented

  5. Hybrid Pressure Retarded Osmosis−Membrane Distillation (PRO−MD) Process for Osmotic Power and Clean Water Generation

    KAUST Repository

    Han, Gang

    2015-05-20

    A novel pressure retarded osmosis−membrane distillation (PRO−MD) hybrid process has been experimentally conceived for sustainable production of renewable osmotic power and clean water from various waters. The proposed PRO−MD system may possess unique advantages of high water recovery rate, huge osmotic power generation, well controlled membrane fouling, and minimal environmental impacts. Experimental results show that the PRO−MD hybrid process is promising that not only can harvest osmotic energy from freshwater but also from wastewater. When employing a 2 M NaCl MD concentrate as the draw solution, ultrahigh power densities of 31.0 W/m2 and 9.3 W/m2 have been demonstrated by the PRO subsystem using deionized water and real wastewater brine as the feeds, respectively. Simultaneously, high purity potable water with a flux of 32.5−63.1 L/(m2.h) can be produced by the MD subsystem at 40−60 °C without any detrimental effects of fouling. The energy consumption in the MD subsystem might be further reduced by applying a heat exchanger in the hybrid system and using low-grade heat or solar energy to heat up the feed solution. The newly developed PRO−MD hybrid process would provide insightful guidelines for the exploration of alternative green technologies for renewable osmotic energy and clean water production.

  6. Trajectories towards clean technology. Example of volatile organic compound emission reductions

    Energy Technology Data Exchange (ETDEWEB)

    Belis-Bergouignan, Marie-Claude; Oltra, Vanessa; Saint Jean, Maider [IFREDE-E3i, University Montesquieu-Bordeaux IV, Avenue Leon Duguit, Pessac 33608 (France)

    2004-02-20

    This article is based on the observation that, up until now, corporate investment has been limited in clean technologies despite the will of governmental authorities to stimulate them in order to cope with the demands of sustainable development. The paper deals with the issue of the development of clean technologies and the role of regulations as clean technology promoters. It tries to apprehend the characteristics and specificity of clean technology from both an empirical and a theoretical point of view, so as to understand which are the most favourable (or inversely, the most detrimental) conditions for their development. We use case studies concerning the reduction of volatile organic compound (VOC) emissions in the chemical and metallurgical industries. These two examples highlight the problems created by the shift from a 'with-solvent paradigm' to a 'solvent-free paradigm' and the way clean technology trajectories may spread within such paradigms. We show that the problem of clean technology development primarily resides in some factors that impede technological adoption, although a strong and mixed incentives framework prevails. Such impediments are sector-specific, leading to different clean technology trajectories among sectors and indicating areas of sectoral intervention that could become the cornerstones of complementary technology policy.

  7. Rock fracture processes in chemically reactive environments

    Science.gov (United States)

    Eichhubl, P.

    2015-12-01

    Rock fracture is traditionally viewed as a brittle process involving damage nucleation and growth in a zone ahead of a larger fracture, resulting in fracture propagation once a threshold loading stress is exceeded. It is now increasingly recognized that coupled chemical-mechanical processes influence fracture growth in wide range of subsurface conditions that include igneous, metamorphic, and geothermal systems, and diagenetically reactive sedimentary systems with possible applications to hydrocarbon extraction and CO2 sequestration. Fracture processes aided or driven by chemical change can affect the onset of fracture, fracture shape and branching characteristics, and fracture network geometry, thus influencing mechanical strength and flow properties of rock systems. We are investigating two fundamental modes of chemical-mechanical interactions associated with fracture growth: 1. Fracture propagation may be aided by chemical dissolution or hydration reactions at the fracture tip allowing fracture propagation under subcritical stress loading conditions. We are evaluating effects of environmental conditions on critical (fracture toughness KIc) and subcritical (subcritical index) fracture properties using double torsion fracture mechanics tests on shale and sandstone. Depending on rock composition, the presence of reactive aqueous fluids can increase or decrease KIc and/or subcritical index. 2. Fracture may be concurrent with distributed dissolution-precipitation reactions in the hostrock beyond the immediate vicinity of the fracture tip. Reconstructing the fracture opening history recorded in crack-seal fracture cement of deeply buried sandstone we find that fracture length growth and fracture opening can be decoupled, with a phase of initial length growth followed by a phase of dominant fracture opening. This suggests that mechanical crack-tip failure processes, possibly aided by chemical crack-tip weakening, and distributed solution-precipitation creep in the

  8. Sustainable development, clean technology and knowledge from industry

    Directory of Open Access Journals (Sweden)

    Sokolović Slobodan M.

    2012-01-01

    Full Text Available Clean technology or clean production is the most important factor for the economic growth of a society and it will play the main role not only in the area of cleaner production, but also in sustainable development. The development of clean technology will be the main factor of the company’s strategy in the future. Each company, which wants to reach the competitive position at the market and wants to be environmentally friendly, has to accept the new approach in corporate management and the strategy of new clean technology. The main principles of clean technology are based on the concept of maximum resource and energy productivity and virtually no waste. This approach may be limited by human resources and the level of their environmental knowledge. Companies are committed to the development of the workers’ skills, and thus to the improvement of the company for the full implementation of the environmental legislation and clean production concept. Based on this commitment, one of Tempus projects is designed to improve the university-enterprise cooperation in the process of creating sustainable industry in Serbia, Bosnia and Herzegovina and the Former Yugoslav Republic of Macedonia. To achieve this goal, partner universities will create special courses on sustainable industry and thus enhance the lifelong learning process and cooperation between industry and universities in the Western Balkan countries.

  9. Method for innovative synthesis-design of chemical process flowsheets

    DEFF Research Database (Denmark)

    Kumar Tula, Anjan; Gani, Rafiqul

    Chemical process synthesis-design involve the identification of the processing route to reach a desired product from a specified set of raw materials, design of the operations involved in the processing route, the calculations of utility requirements, the calculations of waste and emission...... to the surrounding and many more. Different methods (knowledge-based [1], mathematical programming [2], hybrid, etc.) have been proposed and are also currently employed to solve these synthesis-design problems. D’ Anterroches [3] proposed a group contribution based approach to solve the synthesis-design problem...... of chemical processes, where, chemical process flowsheets could be synthesized in the same way as atoms or groups of atoms are synthesized to form molecules in computer aided molecular design (CAMD) techniques [4]. That, from a library of building blocks (functional process-groups) and a set of rules to join...

  10. Conditions for the clean slate effect after success or failure.

    Science.gov (United States)

    Körner, Anita; Strack, Fritz

    2018-03-20

    The act of physically cleaning one's hands may reduce the impact of past experiences, termed clean-slate effect. Cleaning was found to affect negative, neutral, and mildly positive states. We extend this influence to success, a self-serving state. We manipulated success vs. failure and measured changes in optimism (Experiment 1) or self-esteem (Experiment 2). Moreover, we examined boundary conditions for the clean-slate effect. Experiment 1 indicates that the influence of performance on optimism diminishes if participants knew (compared to did not know) they were cleaning their hands. Experiment 2 indicates that the influence of performance on self-esteem diminishes if participants cleaned themselves (compared to an object). These results suggest that the clean-slate effect requires both awareness and self-reference of the cleaning act. Thus, the clean-slate effect seems to depend on both conscious inferences and automatic processes. A meta-analysis across the experiments confirms a moderate-sized clean-slate effect.

  11. Reducing hazardous cleaning product use: a collaborative effort.

    Science.gov (United States)

    Pechter, Elise; Azaroff, Lenore S; López, Isabel; Goldstein-Gelb, Marcy

    2009-01-01

    Workplace hazards affecting vulnerable populations of low-wage and immigrant workers present a special challenge to the practice of occupational health. Unions, Coalition for Occupational Safety and Health (COSH) groups, and other organizations have developed worker-led approaches to promoting safety. Public health practitioners can provide support for these efforts. This article describes a successful multiyear project led by immigrant cleaning workers with their union, the Service Employees International Union (SEIU) Local 615, and with support from the Massachusetts COSH (MassCOSH) to address exposure to hazardous chemicals. After the union had identified key issues and built a strategy, the union and MassCOSH invited staff from the Massachusetts Department of Public Health's Occupational Health Surveillance Program (OHSP) to provide technical information about health effects and preventive measures. Results included eliminating the most hazardous chemicals, reducing the number of products used, banning mixing products, and improving safety training. OHSP's history of public health practice regarding cleaning products enabled staff to respond promptly. MassCOSH's staff expertise and commitment to immigrant workers allowed it to play a vital role.

  12. Systematic methods for synthesis and design of sustainable chemical and biochemical processes

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    Chemical and biochemical process design consists of designing the process that can sustainably manufacture an identified chemical product through a chemical or biochemical route. The chemical product tree is potentially very large; starting from a set of basic raw materials (such as petroleum...... for process intensification, sustainable process design, identification of optimal biorefinery models as well as integrated process-control design, and chemical product design. The lecture will present the main concepts, the decomposition based solution approach, the developed methods and tools together...

  13. Practical issues in laser cleaning of stone and painted artefacts: optimisation procedures and side effects

    Science.gov (United States)

    Pouli, Paraskevi; Oujja, Mohamed; Castillejo, Marta

    2012-02-01

    In the last twenty years lasers have acquired an important role in the study and the preservation of Cultural Heritage (CH) objects and Monuments, as they have effectively illuminated a number of complex diagnostic and restoration problems. Their unique properties have enabled their use in a wide range of conservation applications, since they ensure interventions with precise control, material selectivity and immediate feedback. Surface cleaning, based on laser ablation, is a delicate, critical and irreversible process, which, given the multitude of materials that may be present on a CH object and the often fragile or precarious condition of the original surfaces, is fraught with many potential complications. Therefore it is crucial to choose the best possible laser cleaning methodology for each individual case, which involves optimising the laser parameters according to material properties, as well as the thorough knowledge of the ablation mechanisms involved. In this context the systematic investigation and elucidation of potential damage or side effects occurring upon cleaning is essential, as it delineates the possibilities and limitations of laser ablation and allows the fine-tuning of the operating parameters for a successful cleaning intervention. This paper is an overview of studies investigating the mechanisms which are responsible for the laser-induced discoloration effects. Emphasis is given on the yellowing coloration observed on stonework upon infrared (IR) ablation of pollution encrustations, while the various theories introduced to approach the different physical and/or chemical processes and mechanisms responsible for such side effects are discussed. In this respect the different laser cleaning methodologies, which are based on the use of laser systems with different pulse durations and wavelength characteristics, introduced in order to rectify or prevent discoloration on stonework are presented. In parallel, the darkening phenomena which occur upon

  14. Laser cleaning of varnishes and contaminants on brass

    Energy Technology Data Exchange (ETDEWEB)

    Mateo, M.P.; Ctvrtnickova, T. [Universidad de A Coruna, Dpto. Ingenieria Industrial II, C/ Mendizabal s/n, 15403 Ferrol (Spain); Fernandez, E.; Ramos, J.A. [Instituto Tecnologico de Optica Color e Imagen, AIDO, Dpto. Laser, Valencia (Spain); Yanez, A. [Universidad de A Coruna, Dpto. Ingenieria Industrial II, C/ Mendizabal s/n, 15403 Ferrol (Spain); Nicolas, G. [Universidad de A Coruna, Dpto. Ingenieria Industrial II, C/ Mendizabal s/n, 15403 Ferrol (Spain)], E-mail: gines@cdf.udc.es

    2009-03-01

    The capability of laser ablation to perform controlled cleaning of varnishes containing contaminants and paints used by restorers in artistic objects from brass samples while keeping unaltered the finish structure is demonstrated in this work. Adequate laser energy per pulse and number of laser shots required to perform a suitable cleaning by laser ablation have been optimized. The inspection of the samples before and after the cleaning process by optical microscopy and by Fourier transform infrared spectroscopy (FTIR) technique demonstrated that the finish structure of the surface was intact while the coatings were completely eliminated. Furthermore, a laser-induced plasma spectroscopy (LIBS)-based detection system was applied during the irradiation process for the analysis of the material removal and also for its monitoring.

  15. Laser cleaning of varnishes and contaminants on brass

    International Nuclear Information System (INIS)

    Mateo, M.P.; Ctvrtnickova, T.; Fernandez, E.; Ramos, J.A.; Yanez, A.; Nicolas, G.

    2009-01-01

    The capability of laser ablation to perform controlled cleaning of varnishes containing contaminants and paints used by restorers in artistic objects from brass samples while keeping unaltered the finish structure is demonstrated in this work. Adequate laser energy per pulse and number of laser shots required to perform a suitable cleaning by laser ablation have been optimized. The inspection of the samples before and after the cleaning process by optical microscopy and by Fourier transform infrared spectroscopy (FTIR) technique demonstrated that the finish structure of the surface was intact while the coatings were completely eliminated. Furthermore, a laser-induced plasma spectroscopy (LIBS)-based detection system was applied during the irradiation process for the analysis of the material removal and also for its monitoring

  16. Carbon Dioxide Nucleation as a Novel Cleaning Method for Sodium Alginate Fouling Removal from Reverse Osmosis Membranes desalination

    KAUST Repository

    Alnajjar, Heba

    2017-01-01

    in foulants aggregates formation. Although there are some physical techniques that can maintain the membrane performance without reducing its lifetime, only chemical cleanings are still commonly used in RO plants. In this study, a novel cleaning method

  17. TCV mirrors cleaned by plasma

    Directory of Open Access Journals (Sweden)

    L. Marot

    2017-08-01

    Full Text Available Metallic mirrors exposed in TCV tokamak were cleaned by plasma in laboratory. A gold (Au mirror was deposited with 185–285nm of amorphous carbon (aC:D film coming from the carbon tiles of TCV. Another molybdenum (Mo mirror had a thicker deposit due to a different location within the tokamak. The thickness measurements were carried out using ellipsometry and the reflectivity measurements performed by spectrophotometry revealed a decrease of the specular reflectivity in the entire range (250–2500nm for the Mo mirror and specifically in the visible spectrum for the Au. Comparison of the simulated reflectivity using a refractive index of 1.5 and a Cauchy model for the aC:D gives good confidence on the estimated film thickness. Plasma cleaning using radio frequency directly applied to a metallic plate where the mirrors were fixed demonstrated the ability to remove the carbon deposits. A mixture of 50% hydrogen and 50% helium was used with a −200V self-bias. Due to the low sputtering yield of He and the low chemical erosion of hydrogen leading to volatile molecules, 20h of cleaning were needed for Au mirror and more than 60h for Mo mirror. Recovery of the reflectivity was not complete for the Au mirror most likely due to damage of the surface during tokamak exposure (breakdown phenomena.

  18. Hard surface biocontrol in hospitals using microbial-based cleaning products.

    Directory of Open Access Journals (Sweden)

    Alberta Vandini

    Full Text Available Healthcare-Associated Infections (HAIs are one of the most frequent complications occurring in healthcare facilities. Contaminated environmental surfaces provide an important potential source for transmission of many healthcare-associated pathogens, thus indicating the need for new and sustainable strategies.This study aims to evaluate the effect of a novel cleaning procedure based on the mechanism of biocontrol, on the presence and survival of several microorganisms responsible for HAIs (i.e. coliforms, Staphyloccus aureus, Clostridium difficile, and Candida albicans on hard surfaces in a hospital setting.The effect of microbial cleaning, containing spores of food grade Bacillus subtilis, Bacillus pumilus and Bacillus megaterium, in comparison with conventional cleaning protocols, was evaluated for 24 weeks in three independent hospitals (one in Belgium and two in Italy and approximately 20000 microbial surface samples were collected.Microbial cleaning, as part of the daily cleaning protocol, resulted in a reduction of HAI-related pathogens by 50 to 89%. This effect was achieved after 3-4 weeks and the reduction in the pathogen load was stable over time. Moreover, by using microbial or conventional cleaning alternatively, we found that this effect was directly related to the new procedure, as indicated by the raise in CFU/m2 when microbial cleaning was replaced by the conventional procedure. Although many questions remain regarding the actual mechanisms involved, this study demonstrates that microbial cleaning is a more effective and sustainable alternative to chemical cleaning and non-specific disinfection in healthcare facilities.This study indicates microbial cleaning as an effective strategy in continuously lowering the number of HAI-related microorganisms on surfaces. The first indications on the actual level of HAIs in the trial hospitals monitored on a continuous basis are very promising, and may pave the way for a novel and cost

  19. Hard surface biocontrol in hospitals using microbial-based cleaning products.

    Science.gov (United States)

    Vandini, Alberta; Temmerman, Robin; Frabetti, Alessia; Caselli, Elisabetta; Antonioli, Paola; Balboni, Pier Giorgio; Platano, Daniela; Branchini, Alessio; Mazzacane, Sante

    2014-01-01

    Healthcare-Associated Infections (HAIs) are one of the most frequent complications occurring in healthcare facilities. Contaminated environmental surfaces provide an important potential source for transmission of many healthcare-associated pathogens, thus indicating the need for new and sustainable strategies. This study aims to evaluate the effect of a novel cleaning procedure based on the mechanism of biocontrol, on the presence and survival of several microorganisms responsible for HAIs (i.e. coliforms, Staphyloccus aureus, Clostridium difficile, and Candida albicans) on hard surfaces in a hospital setting. The effect of microbial cleaning, containing spores of food grade Bacillus subtilis, Bacillus pumilus and Bacillus megaterium, in comparison with conventional cleaning protocols, was evaluated for 24 weeks in three independent hospitals (one in Belgium and two in Italy) and approximately 20000 microbial surface samples were collected. Microbial cleaning, as part of the daily cleaning protocol, resulted in a reduction of HAI-related pathogens by 50 to 89%. This effect was achieved after 3-4 weeks and the reduction in the pathogen load was stable over time. Moreover, by using microbial or conventional cleaning alternatively, we found that this effect was directly related to the new procedure, as indicated by the raise in CFU/m2 when microbial cleaning was replaced by the conventional procedure. Although many questions remain regarding the actual mechanisms involved, this study demonstrates that microbial cleaning is a more effective and sustainable alternative to chemical cleaning and non-specific disinfection in healthcare facilities. This study indicates microbial cleaning as an effective strategy in continuously lowering the number of HAI-related microorganisms on surfaces. The first indications on the actual level of HAIs in the trial hospitals monitored on a continuous basis are very promising, and may pave the way for a novel and cost-effective strategy

  20. Optimization and Prototyping of Medium Pressure Water (MPW) Depaint Process, Tri-Service Committee on Corrosion Proceedings

    National Research Council Canada - National Science Library

    Stropki, John

    1994-01-01

    ... and cleaning of aircraft with hazardous chemicals. The means of determining the viability of this environmentally safer blast process was predicated on establishing a set of process parameters at which paint stripping was accomplished...

  1. Effects of micro- and nano-structures on the self-cleaning behaviour of lotus leaves

    Science.gov (United States)

    Cheng, Y. T.; Rodak, D. E.; Wong, C. A.; Hayden, C. A.

    2006-03-01

    When rain falls on lotus leaves water beads up with a high contact angle. The water drops promptly roll off the leaves, collecting dirt along the way. This self-cleaning ability or lotus effect has, in recent years, stimulated much research effort worldwide for a variety of applications ranging from self-cleaning window glasses, paints, and fabrics to low friction surfaces. What are the mechanisms giving rise to the lotus effect? Although chemical composition and surface structure are believed important, a systematic experimental investigation of their effects is still lacking. By altering the surface structure of the leaves while keeping their chemical composition approximately the same, we report in this study the influence of micro- and nano-scale structures on the wetting behaviour of lotus leaves. The findings of this work may help design self-cleaning surfaces and improve our understanding of wetting mechanisms.

  2. Development of clean soil technology using coals as oily/tarry contaminant removal

    International Nuclear Information System (INIS)

    Ignasiak, T.; Szymocha, K.; Carson, D.; Ignasiak, B.

    1991-01-01

    A Clean Soil Process for the treatment of oil/tar contaminated soils has been developed. The mechanics, of the clean-up process that utilizes coal as a cleaning medium is described. The experience and results obtained in the batch-scale testing as well as in the 250 kg/hr continuous facility have been applied for a conceptual design of a 200 t/day mobile plant

  3. Development of clean coal and clean soil technologies using advanced agglomeration techniques

    International Nuclear Information System (INIS)

    Ignasiak, B.; Ignasiak, T.; Szymocha, K.

    1990-01-01

    Three major topics are discussed in this report: (1) Upgrading of Low Rank Coals by the Agflotherm Process. Test data, procedures, equipment, etc., are described for co-upgrading of subbituminous coals and heavy oil; (2) Upgrading of Bituminous Coals by the Agflotherm Process. Experimental procedures and data, bench and pilot scale equipments, etc., for beneficiating bituminous coals are described; (3) Soil Clean-up and Hydrocarbon Waste Treatment Process. Batch and pilot plant tests are described for soil contaminated by tar refuse from manufactured gas plant sites. (VC)

  4. CORAL REEF BIOLOGICAL CRITERIA: USING THE CLEAN ...

    Science.gov (United States)

    Coral reefs are declining at unprecedented rates worldwide due to multiple interactive stressors including climate change and land-based sources of pollution. The Clean Water Act (CWA) can be a powerful legal instrument for protecting water resources, including the biological inhabitants of coral reefs. The objective of the CWA is to restore and maintain the chemical, physical and biological integrity of water resources. Coral reef protection and restoration under the Clean Water Act begins with water quality standards - provisions of state or Federal law that consist of a designated use(s) for the waters of the United States and water quality criteria sufficient to protect the uses. Aquatic life use is the designated use that is measured by biological criteria (biocriteria). Biocriteria are expectations set by a jurisdiction for the quality and quantity of living aquatic resources in a defined waterbody. Biocriteria are an important addition to existing management tools for coral reef ecosystems. The Technical Support Document “Coral Reef Biological Criteria: Using the Clean Water Act to Protect a National Treasure” will provide a framework to aid States and Territories in their development, adoption, and implementation of coral reef biocriteria in their respective water quality standards. The Technical Support Document “Coral Reef Biological Criteria: Using the Clean Water Act to Protect a National Treasure” will provide a framework for coral re

  5. Wet chemical treatment of boron doped emitters on n-type (1 0 0) c-Si prior to amorphous silicon passivation

    Energy Technology Data Exchange (ETDEWEB)

    Meddeb, H., E-mail: hosny.meddeb@gmail.com [KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh (Saudi Arabia); IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Research and Technology Center of Energy, Photovoltaic Department, Borj-Cedria Science and Technology Park, BP 95, 2050 (Tunisia); University of Carthage, Faculty of Sciences of Bizerta (Tunisia); Bearda, T.; Recaman Payo, M.; Abdelwahab, I. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Abdulraheem, Y. [Electrical Engineering Department, College of Engineering & Petroleum, Kuwait University, P.O. Box 5969, 13060 Safat (Kuwait); Ezzaouia, H. [Research and Technology Center of Energy, Photovoltaic Department, Borj-Cedria Science and Technology Park, BP 95, 2050 (Tunisia); Gordon, I.; Szlufcik, J. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Poortmans, J. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Department of Electrical Engineering (ESAT), K.U. Leuven, 3001 Leuven (Belgium); Faculty of Sciences, University of Hasselt, Martelarenlaan 42, 3500 Hasselt (Belgium)

    2015-02-15

    Highlights: • The influence of the cleaning process using different HF-based cleaning on the amorphous silicon passivation of homojunction boron doped emitters is analyzed. • The effect of boron doping level on surface characteristics after wet chemical cleaning: For heavily doped surfaces, the reduction in contact angle was less pronounced, which proves that such surfaces are more resistant to oxide formation and remain hydrophobic for a longer time. In the case of low HF concentration, XPS measurements show higher oxygen concentrations for samples with higher doping level, probably due to the incomplete removal of the native oxide. • Higher effective lifetime is achieved at lower doping for all considered different chemical pre-treatments. • A post-deposition annealing improves the passivation level yielding emitter saturation currents determined by Auger recombination in the order of 70 fA/cm{sup 2} and below. • The dominance of Auger recombination over other type of B-induced defects on lifetime quality in the case of our p+ emitter. - Abstract: The influence of the cleaning process on the amorphous silicon passivation of homojunction emitters is investigated. A significant variation in the passivation quality following different cleaning sequences is not observed, even though differences in cleaning performance are evident. These results point out the effectiveness of our cleaning treatment and provide a hydrogen termination for intrinsic amorphous silicon passivation. A post-deposition treatment improves the passivation level yielding emitter saturation currents determined by Auger recombination in the order of 70 fA/cm{sup 2} and below.

  6. Optimization of Ultrasonic Fabric Cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Hand, T.E.

    1998-05-13

    The fundamental purpose of this project was to research and develop a process that would reduce the cost and improve the environmental efficiency of the present dry-cleaning industry. This second phase of research (see report KCP-94-1006 for information gathered during the first phase) was intended to allow the optimal integration of all factors of ultrasonic fabric cleaning. For this phase, Garment Care performed an extensive literature search and gathered data from other researchers worldwide. The Garment Care-AlliedSignal team developed the requirements for a prototype cleaning tank for studies and acquired that tank and the additional equipment required to use it properly. Garment Care and AlliedSignal acquired the transducers and generators from Surftran Martin-Walter in Sterling Heights, Michigan. Amway's Kelly Haley developed the test protocol, supplied hundreds of test swatches, gathered the data on the swatches before and after the tests, assisted with the cleaning tests, and prepared the final analysis of the results. AlliedSignal personnel, in conjunction with Amway and Garment Care staff, performed all the tests. Additional planning is under way for future testing by outside research facilities. The final results indicated repeatable performance and good results for single layered fabric swatches. Swatches that were cleaned as a ''sandwich,'' that is, three or more layers.

  7. ACToR Chemical Structure processing using Open Source ...

    Science.gov (United States)

    ACToR (Aggregated Computational Toxicology Resource) is a centralized database repository developed by the National Center for Computational Toxicology (NCCT) at the U.S. Environmental Protection Agency (EPA). Free and open source tools were used to compile toxicity data from over 1,950 public sources. ACToR contains chemical structure information and toxicological data for over 558,000 unique chemicals. The database primarily includes data from NCCT research programs, in vivo toxicity data from ToxRef, human exposure data from ExpoCast, high-throughput screening data from ToxCast and high quality chemical structure information from the EPA DSSTox program. The DSSTox database is a chemical structure inventory for the NCCT programs and currently has about 16,000 unique structures. Included are also data from PubChem, ChemSpider, USDA, FDA, NIH and several other public data sources. ACToR has been a resource to various international and national research groups. Most of our recent efforts on ACToR are focused on improving the structural identifiers and Physico-Chemical properties of the chemicals in the database. Organizing this huge collection of data and improving the chemical structure quality of the database has posed some major challenges. Workflows have been developed to process structures, calculate chemical properties and identify relationships between CAS numbers. The Structure processing workflow integrates web services (PubChem and NIH NCI Cactus) to d

  8. Influence of Dry Cleaning on the Electrical Resistance of Screen Printed Conductors on Textiles

    Directory of Open Access Journals (Sweden)

    Kazani Ilda

    2016-09-01

    Full Text Available Electrically conducting inks were screen printed on various textile substrates. The samples were dry cleaned with the usual chemicals in order to investigate the influence of the mechanical treatment on the electrical conductivity. It was found that dry cleaning has a tremendous influence on this electrical conductivity. For several samples, it is observed that the electrical resistance increases with the square of the number of dry cleaning cycles. In order to explain this observation a theoretical model and a numerical simulation have been carried out, by assuming that dry cleaning cycles introduce a crack in the conducting layer. The theoretical analysis and the numerical analysis both confirmed the experimental observations.

  9. Morphological analysis of three wound-cleaning processes on potentially contamined wounds in rats

    Directory of Open Access Journals (Sweden)

    d'Acampora Armando José

    2006-01-01

    Full Text Available PURPOSE: To evaluate the inflammatory response of potentially infected wounds treated with isotonic saline solution, chlorhexidine and PVP-I, seven days after surgery. METHODS: Thirty-two male rats were used, divided into 4 groups. All animals had their surgical wounds infected with a standard bacterial inoculum. Control group (A: animals had their surgical wounds sutured without any kind of cleaning. Saline solution group (B: animals had their wounds cleaned with saline solution. Chlorhexidine group (C: animals had their wounds cleaned with chlorhexidine. PVP-I group (D: animals had their wounds cleaned with PVP-I. Seven days after surgery, all the animals had their skin submitted to microscopic and macroscopic evaluation. RESULTS: Edema was found on all histological slices analyzed, as well as vascular proliferation and congestion. Groups A and D showed presence of mild neutrophilic infiltrate, and moderate lymphocytic and macrophage infiltrate. Group B showed severe neutrophilic, macrophage, and lymphocytic infiltrate. Group C showed moderate neutrophilic, macrophage, and lymphocytic infiltrate. CONCLUSION: Group D was the group which showed inflammatory infiltrate most similar to the group that was not submitted to treatment.

  10. Some impacts of the 1990 Clean Air Act and state clean-air regulations on the fertilizer industry

    International Nuclear Information System (INIS)

    Breed, C.E.; Kerns, O.S.

    1992-01-01

    The Clean Air Act amendments of 1990 will intensify national efforts to reduce air pollution. They will have major impacts on governmental agencies and on industrial and commercial facilities throughout the country. As with other industries, it is essential for fertilizer dealers and producers to understand how these changes to the Clean Air Act can significantly change the way they do business. This paper is proffered as an overview of ways in which the 1990 amendments to the Clean Air Act may impact the fertilizer industry. The nonattainment, toxics, and permit provisions of the amended act will be three areas of particular concern to the fertilizer industry. Implementation of the new regulatory requirements of this legislation promises to be a long and onerous process for all concerned. However, it appears that state and local regulations may have a much more profound impact on the fertilizer industry than the new Clean Air Act

  11. Chemical treatment of coal by grinding and aqueous caustic leaching

    Energy Technology Data Exchange (ETDEWEB)

    Balaz, P.; LaCount, R.B.; Kern, D.G.; Turcaniova, L. [Slovak Academy of Sciences, Kosice (Slovakia). Inst. of Geotechnics

    2001-04-01

    The aim of this work has been to point out the possibility of using GACL process for chemical cleaning of brown coal Nivaky (Slovakia) and Pittsburgh coal. Simultaneous grinding and aqueous chemical leaching, which is the principle of the process, reduces the inorganic and inorganic sulfur content in both coals. Dearsenificiation nearly up to 96% is detected in GACL-treated samples of Novaky coal. The possibility of enhancing the recovery of humic acid as a consequence of GACL treatment is demonstrated. The process under study works under atmospheric pressure, temperature of 90{degree}C and NaOH consumption, which is six times lower compared with the MCL process. Further research is needed to minimize the wear of grinding media and to improve the washing step. 24 refs., 7 figs., 3 tabs.

  12. New Vistas in Chemical Product and Process Design

    DEFF Research Database (Denmark)

    Zhang, Lei; Babi, Deenesh Kavi; Gani, Rafiqul

    2016-01-01

    Design of chemicals-based products is broadly classified into those that are process centered and those that are product centered. In this article, the designs of both classes of products are reviewed from a process systems point of view; developments related to the design of the chemical product......, its corresponding process, and its integration are highlighted. Although significant advances have been made in the development of systematic model-based techniques for process design (also for optimization, operation, and control), much work is needed to reach the same level for product design....... Timeline diagrams illustrating key contributions in product design, process design, and integrated product-process design are presented. The search for novel, innovative, and sustainable solutions must be matched by consideration of issues related to the multidisciplinary nature of problems, the lack...

  13. An analysis of the effects of osmotic backwashing on the seawater reverse osmosis process.

    Science.gov (United States)

    Park, JunYoung; Jeong, WooWon; Nam, JongWoo; Kim, JaeHun; Kim, JiHoon; Chon, Kangmin; Lee, Euijong; Kim, HyungSoo; Jang, Am

    2014-01-01

    Fouling control is an important consideration in the design and operation of membrane-based water treatment processes. It has been generally known that chemical cleaning is still the most common method to remove foultants and maintain the performance of reverse osmosis (RO) desalination. Regardless of the chemical membrane cleaning methods applied effectively, however, frequent chemical cleaning can shorten the membrane life. In addition, it also increases operating and maintenance costs due to the waste chemical disposal. As an alternative, osmotic backwashing can be applied to RO membranes by diluting the concentration polarization (CP) layer. In this study, the effects of osmotic backwashing were analysed under different total dissolved salts (TDSs) and backwashing conditions, and the parameters of the osmotic backwashing were evaluated. The results of the analysis based on the properties of the organic matters found in raw water showed that the cleaning efficiency in respect to the fouling by hydrophilic organic matters was the greatest. Osmotic backwashing was carried out by changing the TDS of the permeate. As a result, the backwashing volume decreased with time due to the CP of the permeate and the backwashing volume. The difference in the osmotic pressure between the raw water and the permeate (Delta pi) also decreased as time passed. It was confirmed that when the temperature of the effluent was high, both the cleaning efficiency and the backwashing volume, which inpours at the same time, increased. When the circulation flow of the effluent was high, both the cleaning efficiency and the backwashing volume increased.

  14. Effectiveness of clean-up procedures on stain susceptibility of different orthodontic adhesives

    Directory of Open Access Journals (Sweden)

    Swati Pundlik Mane

    2014-01-01

    Conclusion: Chemical-cure adhesive showed higher stain susceptibility than light-cure adhesive in all clean-up procedures. Both adhesives would show less stain susceptibility with polishing step with rubber cup and pumice.

  15. Sustainable Chemical Processes and Products. New Design Methodology and Design Tools

    OpenAIRE

    Korevaar, G.

    2004-01-01

    The current chemical industry is not sustainable, which leads to the fact that innovation of chemical processes and products is too often hazardous for society in general and the environment in particular. It really is a challenge to implement sustainability considerations in the design activities of chemical engineers. Therefore, the main question of this thesis is: how can a trained chemical engineer develop a conceptual design of a chemical process or a chemical product in such a way that ...

  16. Performances in Tank Cleaning

    Directory of Open Access Journals (Sweden)

    Fanel-Viorel Panaitescu

    2018-03-01

    Full Text Available There are several operations which must do to maximize the performance of tank cleaning. The new advanced technologies in tank cleaning have raised the standards in marine areas. There are many ways to realise optimal cleaning efficiency for different tanks. The evaluation of tank cleaning options means to start with audit of operations: how many tanks require cleaning, are there obstructions in tanks (e.g. agitators, mixers, what residue needs to be removed, are cleaning agents required or is water sufficient, what methods can used for tank cleaning. After these steps, must be verify the results and ensure that the best cleaning values can be achieved in terms of accuracy and reliability. Technology advancements have made it easier to remove stubborn residues, shorten cleaning cycle times and achieve higher levels of automation. In this paper are presented the performances in tank cleaning in accordance with legislation in force. If tank cleaning technologies are effective, then operating costs are minimal.

  17. Chemical kinetics and oil shale process design

    Energy Technology Data Exchange (ETDEWEB)

    Burnham, A.K.

    1993-07-01

    Oil shale processes are reviewed with the goal of showing how chemical kinetics influences the design and operation of different processes for different types of oil shale. Reaction kinetics are presented for organic pyrolysis, carbon combustion, carbonate decomposition, and sulfur and nitrogen reactions.

  18. New challenges to air/gas cleaning systems

    Energy Technology Data Exchange (ETDEWEB)

    Kovach, J.L. [NUCON International, Inc., Columbus, OH (United States)

    1997-08-01

    This paper discusses the need for changes in the design and manufacturing of air and gas cleaning systems to meet waste management and site remediation requirements. Current design and manufacturing practices are primarily directed toward evaluating operational problems with existing systems in nuclear reactor facilities. However, nuclear waste management needs have developed which are much broader in scope and have different processing conditions. Numerous examples of air cleaning needs for waste management activities are provided; the major differences from operating facility needs are the requirement for continuous effluent treatment under widely different processing conditions. Related regulatory issues are also discussed briefly. 1 ref.

  19. Genesis Solar Wind Collector Cleaning Assessment: Update on 60336 Sample Case Study

    Science.gov (United States)

    Goreva, Y. S.; Allums, K. K.; Gonzalez, C. P.; Jurewicz, A. J.; Burnett, D. S.; Allton, J. H.; Kuhlman, K. R.; Woolum, D.

    2015-01-01

    To maximize the scientific return of Genesis Solar Wind return mission it is necessary to characterize and remove a crash-derived particle and thin film surface contamination. A small subset of Genesis mission collector fragments are being subjected to extensive study via various techniques. Here we present an update on the sample 60336, a Czochralski silicon (Si-CZ) based wafer from the bulk array (B/C). This sample has undergone multiple cleaning steps (see the table below): UPW spin wash, aggressive chemical cleanings (including aqua regia, hot xylene and RCA1), as well as optical and chemical (EDS, ToF-SIMS) imaging. Contamination appeared on the surface of 60336 after the initial 2007 UPW cleaning. Aqua regia and hot xylene treatment (8/13/2013) did little to remove contaminants. The sample was UPW cleaned for the third time and imaged (9/16/13). The UPW removed the dark stains that were visible on the sample. However, some features, like "the Flounder" (a large, 100 micron feature in Fig. 1b) appeared largely intact, resisting all previous cleaning efforts. These features were likely from mobilized adhesive, derived from the Post-It notes used to stabilize samples for transport from Utah after the hard landing. To remove this contamination, an RCA step 1 organic cleaning (RCA1) was employed. Although we are still uncertain on the nature of the Flounder and why it is resistant to UPW and aqua regia/hot xylene treatment, we have found RCA1 to be suitable for its removal. It is likely that the glue from sticky pads used during collector recovery may have been a source for resistant organic contamination [9]; however [8] shows that UPW reaction with crash-derived organic contamination does not make particle removal more difficult.

  20. Forward Osmosis/Low Pressure Reverse Osmosis for Water Reuse: Removal of Organic Micropollutants, Fouling and Cleaning

    KAUST Repository

    Linares, Rodrigo

    2011-07-01

    Forward osmosis (FO) is a natural process in which a solution with high concentration of solutes is diluted when being in contact, through a semipermeable membrane, with a low concentration solution. This osmotic process has been demonstrated to be efficient to recover wastewater effluents while diluting a saline draw solution. Nevertheless, the study of the removal of micropollutants by FO is barely described in the literature. This research focuses on the removal of these substances spiked in a secondary wastewater effluent, while diluting water from the Red Sea, generating feed water that can be desalinated with a low pressure reverse osmosis (LPRO) system. Another goal of this work is to characterize the fouling of the FO membrane, and its effect on micropollutants rejection, as well as the membrane cleaning efficiency of different methods. When considering only FO with a clean membrane, the rejection of the hydrophilic neutral compounds was between 48.6% and 84.7%, for the hydrophobic neutrals the rejection ranged from 40.0% to 87.5%, and for the ionic compounds the rejections were between 92.9% and 96.5%. With a fouled membrane, the rejections were between 44.6% to 95.2%, 48.7% to 91.5% and 96.9% to 98.6%, respectively. These results suggest that, except for the hydrophilic neutral compounds, the rejection of the micropollutants is increased by the fouling layer, possibly due to the higher hydrophilicity of the FO fouled membrane compared to the clean one, the increased adsorption capacity and reduced mass transport capacity, membrane swelling, and the higher negative charge of the surface, related to the foulants. However, when coupled with low pressure reverse osmosis, the rejections for both, the clean and fouled membrane, increased above 98%. The fouling layer, after characterizing the wastewater effluent and the concentrated wastewater after the FO process, proved to be composed of biopolymers, which can be removed with air scouring during short periods

  1. Decontamination of radioactive contaminated protective wear using dry cleaning solvent

    International Nuclear Information System (INIS)

    Muthiah, Pushpa; Chitra, S.; Paul, Biplob

    2013-01-01

    Liquid waste generated by conventional decontamination of radioactive contaminated cotton protective wear using detergent affects the chemical treatment of the plant. To reduce the generation of aqueous detergent waste, dry cleaning of cotton protective wear, highly soiled with oil and grease towards decontamination was tried with organic solvents. Mineral turpentine oil (MTO) among various other organic solvents was identified as a suitable organic solvent. As MTO leaves characteristic odour on the cloth, various commercial fragrances for the removal of the odour were tried. Application of the optimised dry cleaning solvent and commercial fragrance was adopted in plant scale operation. (author)

  2. Idaho Chemical Processing Plant Process Efficiency improvements

    International Nuclear Information System (INIS)

    Griebenow, B.

    1996-03-01

    In response to decreasing funding levels available to support activities at the Idaho Chemical Processing Plant (ICPP) and a desire to be cost competitive, the Department of Energy Idaho Operations Office (DOE-ID) and Lockheed Idaho Technologies Company have increased their emphasis on cost-saving measures. The ICPP Effectiveness Improvement Initiative involves many activities to improve cost effectiveness and competitiveness. This report documents the methodology and results of one of those cost cutting measures, the Process Efficiency Improvement Activity. The Process Efficiency Improvement Activity performed a systematic review of major work processes at the ICPP to increase productivity and to identify nonvalue-added requirements. A two-phase approach was selected for the activity to allow for near-term implementation of relatively easy process modifications in the first phase while obtaining long-term continuous improvement in the second phase and beyond. Phase I of the initiative included a concentrated review of processes that had a high potential for cost savings with the intent of realizing savings in Fiscal Year 1996 (FY-96.) Phase II consists of implementing long-term strategies too complex for Phase I implementation and evaluation of processes not targeted for Phase I review. The Phase II effort is targeted for realizing cost savings in FY-97 and beyond

  3. Data cleaning in the energy domain

    Science.gov (United States)

    Akouemo Kengmo Kenfack, Hermine N.

    This dissertation addresses the problem of data cleaning in the energy domain, especially for natural gas and electric time series. The detection and imputation of anomalies improves the performance of forecasting models necessary to lower purchasing and storage costs for utilities and plan for peak energy loads or distribution shortages. There are various types of anomalies, each induced by diverse causes and sources depending on the field of study. The definition of false positives also depends on the context. The analysis is focused on energy data because of the availability of data and information to make a theoretical and practical contribution to the field. A probabilistic approach based on hypothesis testing is developed to decide if a data point is anomalous based on the level of significance. Furthermore, the probabilistic approach is combined with statistical regression models to handle time series data. Domain knowledge of energy data and the survey of causes and sources of anomalies in energy are incorporated into the data cleaning algorithm to improve the accuracy of the results. The data cleaning method is evaluated on simulated data sets in which anomalies were artificially inserted and on natural gas and electric data sets. In the simulation study, the performance of the method is evaluated for both detection and imputation on all identified causes of anomalies in energy data. The testing on utilities' data evaluates the percentage of improvement brought to forecasting accuracy by data cleaning. A cross-validation study of the results is also performed to demonstrate the performance of the data cleaning algorithm on smaller data sets and to calculate an interval of confidence for the results. The data cleaning algorithm is able to successfully identify energy time series anomalies. The replacement of those anomalies provides improvement to forecasting models accuracy. The process is automatic, which is important because many data cleaning processes

  4. Corrosion surveillance of the chemical decontamination process in Kuosheng nuclear power plant

    International Nuclear Information System (INIS)

    Wang, L.H.

    2002-01-01

    The Piping Recirculation System (RRS) and reactor water clean-up system (RWCU) of Kuosheng Nuclear Power Plant of Taiwan Power Company were decontaminated by CORD process of Framatome ANP GmbH during the outage at October 2001. This is the first time that CORD process was adopted and applied in Taiwan Nuclear Power Plant. To verify minor corrosion damage and correct process control, the material corrosion condition was monitored during all the stages of the chemical decontamination work. Three kinds of specimen were adopted in this corrosion monitoring, including corrosion coupons for weight loss measurements, electrochemical specimens for on-line corrosion monitoring, and WOL specimens (wedge opening loaded) for stress corrosion evaluation. The measured metal losses from nine coupon materials did not reveal any unexpected or intolerable high corrosion damage from the CORD UV or CORD CS processes. The coupon materials included type 304 stainless steel (SS) with sensitized and as-received thermal history, type 308 weld filler, type CF8 cast SS, nickel base alloy 182 weld filler, Inconel 600, Stellite 6 hard facing alloy, NOREM low cobalt hard facing alloy, and A106B carbon steel (CS). The electrochemical noise (ECN) measurements from three-electrode electrochemical probe precisely depicted the metal corrosion variation with the decontamination process change. Most interestingly, the estimated trend of accumulated metal loss is perfectly corresponding to the total removed activities. The ECN measurements were also used for examining the effect of different SS oxide films pre-formed in NWC and HWC on the decontamination efficiency, and for evaluating the galvanic effect of CS with SS. The existing cracks did not propagate further during the decontamination. The average decontamination factors achieved were 50.8 and 4.2 respectively for RRS and RWCU. (authors)

  5. Clean Cities Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    2004-01-01

    This fact sheet explains the Clean Cities Program and provides contact information for all coalitions and regional offices. It answers key questions such as: What is the Clean Cities Program? What are alternative fuels? How does the Clean Cities Program work? What sort of assistance does Clean Cities offer? What has Clean Cities accomplished? What is Clean Cities International? and Where can I find more information?

  6. Comparative study of pulsed laser cleaning applied to weathered marble surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, P., E-mail: mportcal@upo.es [Department of Physical, Chemical and Natural Systems, Universidad Pablo de Olavide, 41013 Seville (Spain); Antúnez, V.; Ortiz, R.; Martín, J.M. [Department of Physical, Chemical and Natural Systems, Universidad Pablo de Olavide, 41013 Seville (Spain); Gómez, M.A. [Instituto Andaluz de Patrimonio Histórico, Camino de los Descubrimientos s/n, 41092 Seville (Spain); Hortal, A.R.; Martínez-Haya, B. [Department of Physical, Chemical and Natural Systems, Universidad Pablo de Olavide, 41013 Seville (Spain)

    2013-10-15

    The removal of unwanted matter from surface stones is a demanding task in the conservation of cultural heritage. This paper investigates the effectiveness of near-infrared (IR) and ultraviolet (UV) laser pulses for the cleaning of surface deposits, iron oxide stains and different types of graffiti (black, red and green sprays and markers, and black cutting-edge ink) on dolomitic white marble. The performance of the laser techniques is compared to common cleaning methods on the same samples, namely pressurized water and chemical treatments. The degree of cleaning achieved with each technique is assessed by means of colorimetric measurements and X-ray microfluorescence. Eventual morphological changes induced on the marble substrate are monitored with optical and electronic microscopy. It is found that UV pulsed laser ablation at 266 nm manages to clean all the stains except the cutting-edge ink, although some degree of surface erosion is produced. The IR laser pulses at 1064 nm can remove surface deposits and black spray acceptably, but a yellowing is observed on the stone surface after treatment. An economic evaluation shows that pulsed laser cleaning techniques are advantageous for the rapid cleaning of small or inaccessible surface areas, although their extensive application becomes expensive due to the long operating times required.

  7. Comparative study of pulsed laser cleaning applied to weathered marble surfaces

    International Nuclear Information System (INIS)

    Ortiz, P.; Antúnez, V.; Ortiz, R.; Martín, J.M.; Gómez, M.A.; Hortal, A.R.; Martínez-Haya, B.

    2013-01-01

    The removal of unwanted matter from surface stones is a demanding task in the conservation of cultural heritage. This paper investigates the effectiveness of near-infrared (IR) and ultraviolet (UV) laser pulses for the cleaning of surface deposits, iron oxide stains and different types of graffiti (black, red and green sprays and markers, and black cutting-edge ink) on dolomitic white marble. The performance of the laser techniques is compared to common cleaning methods on the same samples, namely pressurized water and chemical treatments. The degree of cleaning achieved with each technique is assessed by means of colorimetric measurements and X-ray microfluorescence. Eventual morphological changes induced on the marble substrate are monitored with optical and electronic microscopy. It is found that UV pulsed laser ablation at 266 nm manages to clean all the stains except the cutting-edge ink, although some degree of surface erosion is produced. The IR laser pulses at 1064 nm can remove surface deposits and black spray acceptably, but a yellowing is observed on the stone surface after treatment. An economic evaluation shows that pulsed laser cleaning techniques are advantageous for the rapid cleaning of small or inaccessible surface areas, although their extensive application becomes expensive due to the long operating times required.

  8. Comparative study of pulsed laser cleaning applied to weathered marble surfaces

    Science.gov (United States)

    Ortiz, P.; Antúnez, V.; Ortiz, R.; Martín, J. M.; Gómez, M. A.; Hortal, A. R.; Martínez-Haya, B.

    2013-10-01

    The removal of unwanted matter from surface stones is a demanding task in the conservation of cultural heritage. This paper investigates the effectiveness of near-infrared (IR) and ultraviolet (UV) laser pulses for the cleaning of surface deposits, iron oxide stains and different types of graffiti (black, red and green sprays and markers, and black cutting-edge ink) on dolomitic white marble. The performance of the laser techniques is compared to common cleaning methods on the same samples, namely pressurized water and chemical treatments. The degree of cleaning achieved with each technique is assessed by means of colorimetric measurements and X-ray microfluorescence. Eventual morphological changes induced on the marble substrate are monitored with optical and electronic microscopy. It is found that UV pulsed laser ablation at 266 nm manages to clean all the stains except the cutting-edge ink, although some degree of surface erosion is produced. The IR laser pulses at 1064 nm can remove surface deposits and black spray acceptably, but a yellowing is observed on the stone surface after treatment. An economic evaluation shows that pulsed laser cleaning techniques are advantageous for the rapid cleaning of small or inaccessible surface areas, although their extensive application becomes expensive due to the long operating times required.

  9. The Synthesis of Anatase Nanoparticles and the Preparation of Photocatalytically Active Coatings Based on Wet Chemical Methods for Self-Cleaning Applications

    Directory of Open Access Journals (Sweden)

    Dejan Verhovšek

    2012-01-01

    Full Text Available We report on an improved sol-gel method for the production of highly photocatalytic titanium dioxide (TiO2 anatase nanoparticles which can provide appropriate control over the final characteristics of the nanoparticles, such as particle size, crystallinity, crystal structure, morphology, and also the degree of agglomeration. The synthesized anatase nanoparticles were characterized using various techniques, such as X-ray powder diffraction (XRD, scanning electron microscopy (SEM, and transmission electron microscopy (TEM, and were tested in coatings for self-cleaning glass and ceramic surfaces. The coatings were prepared using a soft chemistry route and are completely transparent to visible light and exhibit a high photocatalytic effect, which was determined by contact-angle measurements. Finally, it is worth mentioning that both the sol-gel synthesis method and the coating-preparation method are based on a wet chemical process, thus presenting no risk of handling the TiO2 anatase nanoparticles in their potentially hazardous powder form at any stage of our development. Low-price, easy-to-handle, and nontoxic materials were used. Therefore, our work represents an important contribution to the development of TiO2 anatase nanoparticle coatings that provide a high photocatalytic effect and can thus be used for numerous applications.

  10. Aspects of cleaning environmental materials for multi-element analysis, e.g. plant samples

    International Nuclear Information System (INIS)

    Markert, B.

    1992-01-01

    Cleaning of samples is often the first step in the entire procedure of sample preparation in environmental trace element research. The question must generally be raised of whether cleaning is meaningful before chemical investigations with plant material (e.g. for the determination of transfer factors in the soil/plant system) or not (e.g. for food chain analysis in the plant/animal system). The most varied cleaning procedures for plant samples are currently available ranging from dry and wet wiping of the leaf or needle surface up to the complete removal of the cuticule with the aid of chlorofom. There is at present no standardized cleaning procedure for plant samples so that it is frequently not possible to compare analytical data from different working groups studying the same plant species. (orig.)

  11. Plasma cleaning techniques and future applications in environmentally conscious manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Ward, P.P.

    1995-07-01

    Plasmas have frequently been used in industry as a last step surface preparation technique in an otherwise predominantly wet-etch process. The limiting factor in the usefulness of plasma cleaning techniques has been the rate at which organic materials are removed. Recent research in the field of plasma chemistry has provided some understanding of plasma processes. By controlling plasma conditions and gas mixtures, ultra-fast plasma cleaning and etching is possible. With enhanced organic removal rates, plasma processes become more desirable as an environmentally sound alternative to traditional solvent or acid dominated process, not only as a cleaning tool, but also as a patterning and machining tool. In this paper, innovations in plasma processes are discussed including enhanced plasma etch rates via plasma environment control and aggressive gas mixtures. Applications that have not been possible with the limited usefulness of past plasma processes are now approaching the realm of possibility. Some of these possible applications will be discussed along with their impact to environmentally conscious manufacturing.

  12. Modelling de-novo formation of dioxins in the effluent gas cleaning tract of a zinc recycling process

    Energy Technology Data Exchange (ETDEWEB)

    Nordsieck, H.; Peche, R.

    2002-07-01

    Dioxins as well as other chloroaromatics are an unwanted by-product of most metallurgical processes, both in primary metal production and in recycling, such as at the re-use of high-zinc steel dust, as obtained in the second steel melting process using in electric arc furnaces, by extracting the included zinc. for achieving this purpose, the steel dust is treated in a rotary kiln. This resulting zinc oxide is offered to metal working companies in form of fine powder where it is used for galvanizing of components, for example, or for converting the powder pure metal. In the framework of the MINIDIP-project (Minimization of Dioxins in Thermal Industrial Processes: Mechanisms, Monitoring, Abatement) the formation of dioxins was studied as a function of temperature, time, oxygen, and inhibitor addition. The resulting kinetic data are introduced into a computational fluid dynamics (CFD) model, featuring geometric representations of the effluent gas cleaning tract components and the temperature and gas flow field as well as the trajectories and destination of particles different sizes calculated. This CFD model is used to estimate the de-novo formation of dioxins from the moment the gas leaves the rotary kiln until its cleaning, in order to define the role of this part of the plant in the formation of dioxins, as well as the identification and extent of possibilities for minimizing dioxin emissions. (Author)

  13. Superhydrophobic coatings on wood substrate for self-cleaning and EMI shielding

    Science.gov (United States)

    Xing, Yingjie; Xue, Yaping; Song, Jinlong; Sun, Yankui; Huang, Liu; Liu, Xin; Sun, Jing

    2018-04-01

    A layer of superhydrophobic coating having good electromagnetic shielding and self-cleaning performance was fabricated on a wood surface through an electroless copper plated process. The superhydrophobic property of the wood surface was measured by contact angle (CA) and roll-off angle (RA) measurements. The microstructure and chemical composition of the superhydrophobic coating were analyzed by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The analysis revealed that the microscale particles were uniformly distributed on the wood surface and the main component of the coating is metallic copper. The as-prepared Cu coatings on wood substrate exhibit a good superhydrophobicity with water contact angle about 160° and rolling angle less than 5°.

  14. Dual Electrolytic Plasma Processing for Steel Surface Cleaning and Passivation

    Science.gov (United States)

    Yang, L.; Zhang, P.; Shi, J.; Liang, J.; Tian, W. B.; Zhang, Y. M.; Sun, Z. M.

    2017-10-01

    To remove the rust on rebars and passivate the fresh surfaces, electrodes reversing electrolytic plasma processing (EPP) was proposed and conducted in a 10 wt.% Na2CO3 aqueous solution. The morphology and the composition of the surface were investigated by SEM and XPS. Experimental results show that the rust on the surface was removed effectively by cathode EPP, and a passive film containing Cr2O3 was achieved by the succeeding anode EPP treatment, by a simple operation of reversing the bias. The corrosion resistance was evaluated in a 3.5 wt.% NaCl aqueous solution using an electrochemical workstation. In comparison, the corrosion resistance was improved by the succeeding anode EPP treatment, which is evidenced by a positive shift of the open-circuit potential, an increase in the electrochemical impedance representing the inner layer by 76.8% and the decrease in the corrosion current density by 49.6%. This is an effective and environment-friendly technique to clean and passivate rebars and similar steel materials.

  15. SAGE SOLVENT ALTERNATIVES GUIDE: SYSTEM IMPROVEMENTS FOR SELECTING INDUSTRIAL SURFACE CLEANING ALTERNATIVES

    Science.gov (United States)

    The paper describes computer software, called SAGE, that can provide not only cleaning recommendations but also general information on various surface cleaning options. In short, it is an advisory system which can provide users with vital information on the cleaning process optio...

  16. Self-Cleaning Antireflective Optical Coatings

    KAUST Repository

    Guldin, Stefan

    2013-11-13

    Low-cost antireflection coatings (ARCs) on large optical surfaces are an ingredient-technology for high-performance solar cells. While nanoporous thin films that meet the zero-reflectance conditions on transparent substrates can be cheaply manufactured, their suitability for outdoor applications is limited by the lack of robustness and cleanability. Here, we present a simple method for the manufacture of robust self-cleaning ARCs. Our strategy relies on the self-assembly of a block-copolymer in combination with silica-based sol-gel chemistry and preformed TiO2 nanocrystals. The spontaneous dense packing of copolymer micelles followed by a condensation reaction results in an inverse opal-type silica morphology that is loaded with TiO2 photocatalytic hot-spots. The very low volume fraction of the inorganic network allows the optimization of the antireflecting properties of the porous ARC despite the high refractive index of the embedded photocatalytic TiO2 nanocrystals. The resulting ARCs combine high optical and self-cleaning performance and can be deposited onto flexible plastic substrates. © 2013 American Chemical Society.

  17. Surface Analysis of the Laser Cleaned Metal Threads

    Science.gov (United States)

    Sokhan, M.; Hartog, F.; McPhail, D.

    The laser cleaning of the tarnished silver threads was carried out using Nd:YAG laser radiation at IR (1064 nm) and visible wavelengths (532 nm). The preliminary tests were made on the piece of silk with the silver embroidery with the clean and tarnished areas. FIBS and SIMS analysis were used for analysing the condition of the surface before and after laser irradiation. It was found that irradiation below 0.4 J/cm-2 and higher than 1.0 J/cm-2 fluences aggravates the process of tarnishing and leads to the yellowing effect. The results of preliminary tests were used for finding the optimum cleaning regime for the laser cleaning of the real museum artefact: "Women Riding Jacket" dated to the beginning of 18th century.

  18. Development of chemical process for synthesis of polyunsaturated esters

    OpenAIRE

    Vera LÃcia Viana do Nascimento

    2014-01-01

    This work aimed to develop refining processes, chemical alcoholysis followed by separation of fatty acids using the complexation with urea technique for the synthesis of poly-unsaturated esters from waste of fish oils. The special crude fish oil was purchased from Company Campestre - SÃo Paulo. Initially this oil has undergone a process of physical and chemical refining. From the refined oil, an alcoholysis process was carried out to obtain the mixture of free fatty acids. From the hydrolyzed...

  19. Ultra-clean

    International Nuclear Information System (INIS)

    Hergenroether, K.

    1987-01-01

    No other method guarantees such a thorough cleaning of contaminated materials' surfaces. Only ultrasound can reach those cavities crevices and corners where any manual cleaning fails. Furthermore there is no cumbersome and time-consuming manual decontamination which often has to be carried out in glove boxes and hot cells. Depending on the design the cleaning effect can reach from removing adhering dirt particles to removing complete surface layers. (orig./PW) [de

  20. Physical and chemical characterization of bioaerosols - Implications for nucleation processes

    Science.gov (United States)

    Ariya, P. A.; Sun, J.; Eltouny, N. A.; Hudson, E. D.; Hayes, C. T.; Kos, G.

    The importance of organic compounds in the oxidative capacity of the atmosphere, and as cloud condensation and ice-forming nuclei, has been recognized for several decades. Organic compounds comprise a significant fraction of the suspended matter mass, leading to local (e.g. toxicity, health hazards) and global (e.g. climate change) impacts. The state of knowledge of the physical chemistry of organic aerosols has increased during the last few decades. However, due to their complex chemistry and the multifaceted processes in which they are involved, the importance of organic aerosols, particularly bioaerosols, in driving physical and chemical atmospheric processes is still very uncertain and poorly understood. Factors such as solubility, surface tension, chemical impurities, volatility, morphology, contact angle, deliquescence, wettability, and the oxidation process are pivotal in the understanding of the activation processes of cloud droplets, and their chemical structures, solubilities and even the molecular configuration of the microbial outer membrane, all impact ice and cloud nucleation processes in the atmosphere. The aim of this review paper is to assess the current state of knowledge regarding chemical and physical characterization of bioaerosols with a focus on those properties important in nucleation processes. We herein discuss the potential importance (or lack thereof) of physical and chemical properties of bioaerosols and illustrate how the knowledge of these properties can be employed to study nucleation processes using a modeling exercise. We also outline a list of major uncertainties due to a lack of understanding of the processes involved or lack of available data. We will also discuss key issues of atmospheric significance deserving future physical chemistry research in the fields of bioaerosol characterization and microphysics, as well as bioaerosol modeling. These fundamental questions are to be addressed prior to any definite conclusions on the