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Sample records for dewatering ead process

  1. Ultrafine coal single stage dewatering and briquetting process

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, J.W. [Missouri Univ., Rolla, MO (United States). Dept. of Mining Engineering; Honaker, R.Q. [Southern Illinois Univ., Carbondale, IL (United States). Dept. of Mining Engineering

    1995-12-31

    It is well known that a large portion of the pyrite particles in the coal seams of the Illinois Basin are finely disseminated within the coal matrix. In order to liberate these micron size pyrite particles, one must use a fine grinding operation. The ultrafine coal particles are difficult to dewater and create problems in coal transportation, as well as in storage and handling at utility plants. The objective of this research project is to combine the ultrafine coal dewatering and briquetting processes into a single stage operation. This will be accomplished by the use of bitumen based emulsions for dewatering and a compaction device for briquetting. During this reporting period, several types of coal samples with various particle size distributions have been tested for use in the dewatering and briquetting processes. Furthermore, various bitumen emulsions have been tested to determine the optimum dewatering reagent. These dewatering and pelletizing tests were carried out using a lab-scale ram extruder. Discharge from the dewatering and briquetting processes was tested to determine compliance with current federal and state requirements. The influence of bitumen emulsion on the sulfur content of coal pellets made were also examined. In addition, a ram extruder which can be operated continuously to simulate a rotary press operation, has been built and is currently being tested for use in the fine coal dewatering and pelletizing process.

  2. Biosynthesised magnetic iron nanoparticles for sludge dewatering via Fenton process.

    Science.gov (United States)

    Ealias, Anu Mary; Jose, Jephin Varughese; Saravanakumar, M P

    2016-11-01

    The magnetic iron nanoparticles (MFeNp) were biosynthesised using the extract of Cinnamomum tamala (bay leaf) and examined for its efficacy on sludge dewatering. The characteristics of MFeNp were studied using scanning electron microscope (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and x-ray photoelectron spectrometer (XPS) techniques. The presence of polyphenolic compounds were confirmed by FTIR and XPS analysis. The reduction in capillary suction time (CST) (71.36 to 16.5 s) and specific resistance to filtration (SRF) (53.71 × 10(11) to 1.47 × 10(11) m/kg) values have indicated that the use of Fenton nanocatalyst enhanced the sludge dewaterability. The differential scanning calorimetry (DSC) analysis has shown that the mass of bound water in the treated sludge was decreased significantly from 1.45 to 0.92 kg H2O/kg DS. The breakdown of extracellular polymeric substances (EPS) by the MFeNp leads to the significant reduction in proteins, polysaccharides, water content and heavy metals. The optimisation using response surface modelling (RSM) have shown that the maximum removal efficiency of water from the sludge was 85.9 % when the optimum pH (3) MFeNp dosage (50 mg/g DS) and H2O2 dosage (500 mg/g DS) were maintained. The experimental results and the statistical optimisation have suggested that MFeNp can be used as a potential nanocatalyst for the sludge dewaterability and hence it can be used for the agricultural purpose. Graphical abstract Schematic representation of sludge dewatering process.

  3. Development of a Two-Stage Microalgae Dewatering Process – A Life Cycle Assessment Approach

    Science.gov (United States)

    Soomro, Rizwan R.; Zeng, Xianhai; Lu, Yinghua; Lin, Lu; Danquah, Michael K.

    2016-01-01

    Even though microalgal biomass is leading the third generation biofuel research, significant effort is required to establish an economically viable commercial-scale microalgal biofuel production system. Whilst a significant amount of work has been reported on large-scale cultivation of microalgae using photo-bioreactors and pond systems, research focus on establishing high performance downstream dewatering operations for large-scale processing under optimal economy is limited. The enormous amount of energy and associated cost required for dewatering large-volume microalgal cultures has been the primary hindrance to the development of the needed biomass quantity for industrial-scale microalgal biofuels production. The extremely dilute nature of large-volume microalgal suspension and the small size of microalgae cells in suspension create a significant processing cost during dewatering and this has raised major concerns towards the economic success of commercial-scale microalgal biofuel production as an alternative to conventional petroleum fuels. This article reports an effective framework to assess the performance of different dewatering technologies as the basis to establish an effective two-stage dewatering system. Bioflocculation coupled with tangential flow filtration (TFF) emerged a promising technique with total energy input of 0.041 kWh, 0.05 kg CO2 emissions and a cost of $ 0.0043 for producing 1 kg of microalgae biomass. A streamlined process for operational analysis of two-stage microalgae dewatering technique, encompassing energy input, carbon dioxide emission, and process cost, is presented. PMID:26904075

  4. Ultrafine coal single stage dewatering and briquetting process. Technical report, December 1, 1994--February 28, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, J.W.

    1996-03-01

    It is well known that a large portion of the pyrite particles in the coal seams of the Illinois Basin, are finely disseminated within the coal matrix. In order to liberate these micron size pyrite particles, one must use a fine grinding operation. The ultrafine coal particles that are produced are difficult to dewater and they create problems in coal transportation as well as in its storage and handling at utility plants. The objective of this research project is to combine ultrafine coal dewatering and briquetting processes into a single stage operation. This will be accomplished by the use of bitumen based emulsions for dewatering and a compaction device for briquetting. During this reporting period, two types of coal samples have been tested for use in the dewatering and briquetting processes. These tests were carried out using Orimulsion as the dewatering reagent. A ram extruder that can be operated continuously is used to fabricate dewatered pellets. The influence of compaction pressure, curing time, binder concentration (2% to 5%), particle size, and compacting time on the performance of coal pellets have been evaluated in terms of their water resistance and wear vulnerability.

  5. Ultrafine coal single stage dewatering and briquetting process. Technical report, September 1--November 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, J.W. [Univ. of Missouri, Rolla, MO (United States). Dept. of Mining Engineering; Honaker, R.Q. [Southern Illinois Univ., Carbondale, IL (United States). Dept. of Mining Engineering

    1994-12-31

    It is well known that a large portion of the pyrite particles in the coal seams of the Illinois Basin, are finely disseminated within the coal matrix. In order to liberate these micron size pyrite particles, one must use a fine grinding operation. The ultrafine coal particles that are produced are difficult to dewater and they create problems in coal transportation as well as in its storage and handling at utility plants. The objective of this research project is to combine ultrafine coal dewatering and briquetting processes into a single stage operation. This will be accomplished by the use of bitumen based emulsions for dewatering and a compaction device for briquetting. During this reporting period, two types of coal samples have been tested for use in the dewatering and briquetting processes. These tests were carried out in conjunction with a selected hydrophobic binder as the dewatering reagent and an uniaxial hydraulic press. The influence of compaction pressure and binder concentration (2 to 5%) on the performance of coal pellets have been evaluated in terms of their water and wear resistance. A laboratory scale ultrafine coal dewatering and briquetting extruder that can be operated continuously for coal pellets fabrication, has been designed and built, and will be available for testing in the next quarter.

  6. Development of A Continuous Process for Displacement Dewatering

    Energy Technology Data Exchange (ETDEWEB)

    Dave Beck

    2006-10-30

    The subject of this contract was to investigate the viability of a new process for dewatering paper called displacement pressing. The term “displacement pressing” was coined in the 1980s by researchers to describe a paper dewatering process where air is blown through a sheet of paper while it is being pressed. It was shown at that time that the combination of air and low pressing force could dramatically increase both sheet bulk and sheet solids which in theory would translate into huge savings in energy and fiber consumption. But there was a catch. Although the research results were dramatic, no one could figure out a commercially viable process to carry out displacement pressing. All research work had been done with batch processes, and there was no obvious way to convert these processes into a continuous process. By the end of the early1990’s no one was researching in this area because no continuous process existed. Recently we proposed a new method to carry out displacement pressing. Our process uses special pressing fabrics and a special 4 roll press that we call a “Beck Cluster Press” or BCP. The BCP provides a pressurized atmosphere that acts on a moving web of paper and fabrics. The special fabrics designed for this process use this atmosphere to press the sheet and at the same time, these special fabrics force air through the sheet to carry out displacement pressing. 1 Because of the complexity and cost of building the first functioning BCP, a simple simulator was built to confirm and study the process. Although results from this simulator were extremely favorable, financial times were hard in the paper industry. We are grateful for the DOE contract that allowed us to continue research that showed the tremendous benefits of displacement pressing. Specifically, accomplishments from the DOE contract are as follows: 1. A narrow (5” wide sheet) lab Beck Cluster Press (BCP) was started up, and made operational. This press accepts hand sheets and

  7. Stabilization and dewatering of wastewater treatment plants sludge using the Fenton process

    Directory of Open Access Journals (Sweden)

    Abolfazl Azhdarpoor

    2015-11-01

    Full Text Available Wastewater sludge typically contains large amounts of water and organic materials; therefore, its stabilization and dewatering is of particular importance. In this study, Fenton oxidation process is used for stabilization and dewatering of sludge in the output of a wastewater treatment plant. To evaluate the sludge stabilization and dewatering, specific resistance to filtration (SRF, volatile organic compounds (VSS, total suspended solids (TSS, soluble chemical oxygen demand (SCOD and heterotrophic bacteria were measured. During the experiment, the optimal values of various parameters such as pH (2-9, hydrogen peroxide (0.015- 0.18mol/L, Fe2+ (0.008- 0.1mol/L and time (5 - 60 minutes for optimum sludge dewatering and stabilization were investigated. The results showed that the highest percentages of SRF reduction and removal rates of SCOD, VSS and TSS were 99.48, 61, 42, and 41 percent respectively. These results were obtained in optimum pH 5, 0.05 mol/l Fe2+, 0.12 mol/l hydrogen peroxide, and the retention time of 15 minutes. The removal rate of heterotrophic bacteria increased with increasing dose of hydrogen peroxide, so that a removal rate of 84 percent was observed at a dose of 0.18 mol/l. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering.

  8. Nitrogen removal from sludge dewatering effluent through anaerobic ammonia oxidation process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shao-hui; ZHENG Ping; HUA Yu-mei

    2005-01-01

    Anaerobic ammonia oxidation(Anammox) process is a novel and promising wastewater nitrogen removal process. The feasibility of transition of Anammox from denitrification and the performance of lab-scale Anammox biofilm reactor were investigated with sludge dewatering effluent. The results showed that Anammox process could be successfully started up after cultivation of denitrification biofilm and using it as inoculum. The transition of Anammox from denitrification was accomplished within 85 d. Anammox process was found suitable to remove ammonia from sludge dewatering effluent. The effluent ammonia concentration was detected to be 23.11 mgN/L at HRT of 28 h when influent ammonia concentration was fed 245 mgN/L, which was less than that for the national discharge standard Ⅱ (25 mgN/L) of 243.25 mg NH4+ -N/L and 288.31 mg NO2- -N/L.

  9. Bioelectrochemically-assisted anaerobic composting process enhancing compost maturity of dewatered sludge with synchronous electricity generation.

    Science.gov (United States)

    Yu, Hang; Jiang, Junqiu; Zhao, Qingliang; Wang, Kun; Zhang, Yunshu; Zheng, Zhen; Hao, Xiaodi

    2015-10-01

    Bioelectrochemically-assisted anaerobic composting process (AnCBE) with dewatered sludge as the anode fuel was constructed to accelerate composting of dewatered sludge, which could increase the quality of the compost and harvest electric energy in comparison with the traditional anaerobic composting (AnC). Results revealed that the AnCBE yielded a voltage of 0.60 ± 0.02 V, and total COD (TCOD) removal reached 19.8 ± 0.2% at the end of 35 d. The maximum power density was 5.6 W/m(3). At the end of composting, organic matter content (OM) reduction rate increased to 19.5 ± 0.2% in AnCBE and to 12.9 ± 0.1% in AnC. The fuzzy comprehensive assessment (FCA) result indicated that the membership degree of class I of AnCBE compost (0.64) was higher than that of AnC compost (0.44). It was demonstrated that electrogenesis in the AnCBE could improve the sludge stabilization degree, accelerate anaerobic composting process and enhance composting maturity with bioelectricity generation.

  10. Process Design and Economics for the Production of Algal Biomass: Algal Biomass Production in Open Pond Systems and Processing Through Dewatering for Downstream Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Ryan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Markham, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kinchin, Christopher [National Renewable Energy Lab. (NREL), Golden, CO (United States); Grundl, Nicholas [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tan, Eric C.D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Humbird, David [DWH Process Consulting, Denver, CO (United States)

    2016-02-17

    This report describes in detail a set of aspirational design and process targets to better understand the realistic economic potential for the production of algal biomass for subsequent conversion to biofuels and/or coproducts, based on the use of open pond cultivation systems and a series of dewatering operations to concentrate the biomass up to 20 wt% solids (ash-free dry weight basis).

  11. Dewatering studies of fine clean coal

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, B.K.

    1991-01-01

    The main objective of the present research program is to study and understand dewatering characteristics of ultrafine clean coal obtained using the advanced column flotation technique from the Kerr-McGee's Galatia preparation plant fine coal waste stream. It is also the objective of the research program to utilize the basic study results, i.e., surface chemical, particle shape particle size distribution, etc., in developing a cost-effective dewatering method. The ultimate objective is to develop process criteria to obtain a dewatered clean coal product containing less that 20 percent moisture, using the conventional vacuum dewatering equipment. (VC)

  12. Comparative evaluation of microbial and chemical leaching processes for heavy metal removal from dewatered metal plating sludge.

    Science.gov (United States)

    Bayat, Belgin; Sari, Bulent

    2010-02-15

    The purpose of the study described in this paper was to evaluate the application of bioleaching technique involving Acidithiobacillus ferrooxidans to recover heavy metals (Zn, Cu, Ni, Pb, Cd and Cr) in dewatered metal plating sludge (with no sulfide or sulfate compounds). The effect of some conditional parameters (i.e. pH, oxidation-reduction potential (ORP), sulfate production) and operational parameters (i.e. pulp density of the sludge and agitation time) were investigated in a 3l completely mixed batch (CMB) reactor. The metal recovery yields in bioleaching were also compared with chemical leaching of the sludge waste using commercial inorganic acids (sulfuric acids and ferric chloride). The leaching of heavy metals increased with decreasing of pH and increasing of ORP and sulfate production during the bioleaching experiment. Optimum pulp density for bioleaching was observed at 2% (w/v), and leaching efficiency decreased with increasing pulp density in bioleaching experiments. Maximum metal solubilization (97% of Zn, 96% of Cu, 93% of Ni, 84% of Pb, 67% of Cd and 34% of Cr) was achieved at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25+/-2 degrees C during the bioleaching process. The maximum removal efficiencies of 72% and 79% Zn, 70% and 75% Cu, 69% and 73% Ni, 57% and 70% Pb, 55% and 65% Cd, and 11% and 22% Cr were also attained with the chemical leaching using sulfuric acids and ferric chloride, respectively, at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25+/-2 degrees C during the acid leaching processes. The rates of metal leaching for bioleaching and chemical leaching are well described by a kinetic equation related to time. Although bioleaching generally requires a longer period of operation compared to chemical leaching, it achieves higher removal efficiency for heavy metals. The efficiency of leaching processes can be arranged in descending order as follows: bioleaching>ferric chloride leaching>sulfuric acid

  13. Effect of ultrasonic and PAM on sludge dewatering process%超声波联合PAM对污泥脱水性能的影响

    Institute of Scientific and Technical Information of China (English)

    胡东东; 俞志敏; 易允燕

    2014-01-01

    Through measuring the sludge dewatering and settling performance,the effect of Ultrasonic and PAM on sludge dewatering process was studied. Ultrasonic treatment time,dosage of PAM,and concentration of PAM were changed and tested. The orthogonal test revealed that,at ultrasonic treat-ment time of 20 s,dosage of PAM of 100 mg/L,concentration of PAM of 0. 15%,the best sludge dewatering performance could be obtained.%以污泥脱水性能与沉降性能为指标,研究了超声波调理联合PAM对污泥脱水性能的影响。实验结果表明,单独使用超声波调理的最佳调理时间为20 s,此时污泥比阻为0.68×109 s2/g;采用PAM对污泥进行调理时,在浓度为0.1%,投加量为100 mg/L时污泥比阻最小,为0.32×109 s2/g;采用超声波与PAM联合调理时,利用正交试验得到最适合的组合条件为:调理时间20 s、PAM投加量100 mg/L、浓度0.15%。

  14. 正渗透污泥脱水工艺的影响因素研究%Study on influencing factors of forward osmosis sludge dewatering process

    Institute of Scientific and Technical Information of China (English)

    邢珊珊; 朱洪涛

    2014-01-01

    将正渗透技术应用于污泥浓缩脱水,对孔径更大、机械强度更高的低压过滤膜应用于正渗透污泥脱水工艺的可行性及影响因素进行了探索。对比试验证明低压过滤膜由于膜厚度方面的劣势带来的严重浓差极化现象而无法获得良好的水通量,不能满足用于正渗透污泥脱水的要求。对正渗透污泥脱水过程中盐离子反向传质情况的监测分析发现,这一过程受污泥侧盐累积量与污泥含水率两个因素影响,污泥侧盐浓度最终根据试验条件不同而稳定在0.1~0.2 mol/L 内。污泥中混入盐对污泥极限脱水性能存在不利影响而应加以控制。试验用的3种常用污泥絮凝剂使正渗透污泥脱水效果有所提高。%The forward osmosis process was applied for sludge dewatering.The feasibility of low-pressure filter membranes with larger pores and higher mechanical strength used in the forward osmosis sludge dewatering process and its influencing factors were investigated.The results show that a low water flux was resulted by a more severe concentration polarization due to the dis-advantages of the film thickness of low-pressure filter membrane.Therefore,the low-pressure filtration membrane is not suitable for the forward osmosis sludge dewatering process.The reverse salt transfer in the forward osmosis sludge dewatering process is affected by two factors including the salt accumulation of sludge side and the sludge moisture content.The salt concentration of sludge side keeps finally between 0.1 and 0.2 mol/L no matter experimental conditions.Salt dissolved in sludge was proved to have negative effects on sludge dewatering.As a result,the reverse salt transfer in the forward osmosis sludge dewatering process should be minimized as possible.The performance of forward osmosis sludge dewatering process is improved by the three kinds of common sludge coagulants.

  15. [Study on dewatering of activated sludge under applied electric field].

    Science.gov (United States)

    Ji, Xue-Yuan; Wang, Yi-Li; Feng, Jing

    2012-12-01

    For an electro-dewatering process of activated sludge (AS), the effect of pH and conductivity of AS, flocculation conditioning and operation factors of horizontal electric field (voltage magnitude, method of applying electric field and distance between plates) were investigated, and the corresponding optimum electro-dewatering conditions were also obtained. The results showed that the best electro-dewatering effect was achieved for AS without change of its pH value (6.93) and conductivity (1.46 mS x cm(-1)). CPAM conditioning could lead to the increase of 30%-40% in the dewatering rate and accelerate the dewatering process, whereas a slight increase in the electro-dewatering rate. The electro-dewatering rate for conditioned AS reached 83.12% during an electric field applied period of 60 minutes, while this rate for original AS could be 75.31% even the electric field applied period extended to 120 minutes. The delay of applying the electric field had an inhibition effect on the AS electro-dewatering rate. Moreover, the optimum conditions for AS electro-dewatering were followed: CPAM dose of 9 g x kg(-1), electric field strength of 600 V x m(-1), distance between the two plates of 40 mm, dehydration time of 60 minutes. Under above optimum conditions the AS electro-dewatering rate could approach to 85.33% and the moisture content in AS decreased from 99.30% to 95.15% accordingly.

  16. Ead McTaggart: Using VBA to Automate EAD Container List Tagging

    Directory of Open Access Journals (Sweden)

    Randall Miles

    2009-11-01

    Full Text Available Faced with the prospect of converting 200-page container lists to Encoded Archival Description (EAD, the author programmed a Microsoft Access® database using Visual Basic for Applications (VBA to automatically insert the necessary EAD tags and their attributes. Some work is still required to ensure that the container list is properly formatted before importing into the database. Once formatted, the database, named Ead McTaggart, will convert a 7,000 line Microsoft Excel® container list, where each line represents a series, sub-series, or folder title, into a properly tagged EAD container list in about five minutes. As written, Ead McTaggart will handle up to six component levels, but can be modified to handle more. Although many institutions use Archivists' Toolkit or Archon for this functionality, many libraries and archives who have not implemented those tools will find that EAD McTaggert minimizes the work of converting existing container lists to EAD finding aids with a low time investment for implementation.

  17. EAD sim, mas com qual biblioteca?

    Directory of Open Access Journals (Sweden)

    Solange Puntel Mostafa

    2003-07-01

    Full Text Available Discute a importância da biblioteca virtual para o ensino a distância de qualquer curso; para tal o bibliotecário deve ser elemento indispensável na equipe de EAD uma vez que ele conhece as fontes e as formas de organização da informação, o que lhe possibilita atuar inclusive como tutor. Recomenda-se a intervenção do bibliotecário já na fase de planejamento do curso de tal forma que a biblioteca resultante seja um produto/processo tão importante quanto os demais componentes curriculares e customizada ao curso em questão. Destaca a gestão da informação nos sites educacionais, essa outra modalidade de EAD na formação continuada de professores.

  18. The utilization of forward osmosis for coal tailings dewatering

    Science.gov (United States)

    The feasibility of dewatering coal tailings slurry by forward osmosis (FO) membrane process was investigated in this research. A prototype cell was designed and used for the dewatering tests. A cellulosic FO membrane (Hydration Technology Innovations, LLC, Albany, OR) was used fo...

  19. The utilization of forward osmosis for coal tailings dewatering

    Science.gov (United States)

    The feasibility of dewatering coal tailings slurry by forward osmosis (FO) membrane process was investigated in this research. A prototype cell was designed and used for the dewatering tests. A cellulosic FO membrane (Hydration Technology Innovations, LLC, Albany, OR) was used fo...

  20. Thin lift dewatering of oil sand tailings: optimizing dewatering of fluid fine tailings by controlling polymer mixing

    Energy Technology Data Exchange (ETDEWEB)

    Demoz, A.; Munoz, V.; Mikula, R. [Natural Resources Canada, CanmetENERGY, Devon, Alberta (Canada)

    2011-07-01

    In the oil sands industry, dewatering of tailings is an important issue. Recent work has shown that the addition of polymer helps to enhance dewatering of fluid fine tailings. High molecular weight polymers are used to bind small solids which results in a higher floc strength with no significant effect on water chemistry. The problem of this technique is that polymers only achieve optimal performance within a narrow window. This paper aimed at assessing the effect of mixing on the dewatering performance of polymer treatment on mature fine tailings. Tests were performed with different impeller types, mixing speeds and durations. Results demonstrated that the flocculation process is critical in the dewatering process and that working at the optimal flocculation conditions presents considerable benefits. This paper investigated the importance of mixing on the dewatering process and highlighted that further work has to be undertaken to optimize this process.

  1. Advanced Dewatering Systems Development

    Energy Technology Data Exchange (ETDEWEB)

    R.H. Yoon; G.H. Luttrell

    2008-07-31

    A new fine coal dewatering technology has been developed and tested in the present work. The work was funded by the Solid Fuels and Feedstocks Grand Challenge PRDA. The objective of this program was to 'develop innovative technical approaches to ensure a continued supply of environmentally sound solid fuels for existing and future combustion systems with minimal incremental fuel cost.' Specifically, this solicitation is aimed at developing technologies that can (i) improve the efficiency or economics of the recovery of carbon when beneficiating fine coal from both current production and existing coal slurry impoundments and (ii) assist in the greater utilization of coal fines by improving the handling characteristics of fine coal via dewatering and/or reconstitution. The results of the test work conducted during Phase I of the current project demonstrated that the new dewatering technologies can substantially reduce the moisture from fine coal, while the test work conducted during Phase II successfully demonstrated the commercial viability of this technology. It is believed that availability of such efficient and affordable dewatering technology is essential to meeting the DOE's objectives.

  2. THE IDEAL AND THE REAL PROFILE OF TUTORS AND STUDENTS IN LEANING EDUCATION: A PRELIMINARY DISCUSSION ON THE IMPORTANCE OF THE MENTOR IN THE PROCESS OF EAD.

    Directory of Open Access Journals (Sweden)

    Priscilla França Fernandes

    2012-12-01

    Full Text Available Introduction – The distance learning has an important role in social inclusion, training professionals for the job market. The same reasons that favor the entry of these students in distance courses act contrary and dropout rate remains high. The analysis of profiles of students and tutors it is important to understand the reasons for avoidance.Purpose – Knowing thecurrent profileand theexpected characteristicsof the tutorsand students of distance education, in order tocomparethe ideal andreal,to understand the permanenceof these actorsor notand thereforeassessmentof the directionof this mode of educationin the trainingof professionals in the XXI century.Material and Methods - Study literature review, held from the survey articles indexed in the SciELO database, Medline, Lilacs.Conclusion - We conclude thatthe challengesarevastfor the distance education,particularlyin regardto technologiesand profileof students and tutors involved, suggestingarethinkingofeducational practice, in orderto minimizethe negative effects ofthis process.

  3. Modelagem do processo de desidratação de lodo anaeróbio em leitos de secagem simulados Anaerobic sludge dewatering process modeling in simulated drying beds

    Directory of Open Access Journals (Sweden)

    Sérgio R. A. Soares

    2001-05-01

    Full Text Available O emprego de leitos de secagem para a desidratação de lodo de descarte de reatores UASB, constitui excelente alternativa, face a sua simplicidade operacional e aos reduzidos custos de implantação. Este trabalho apresenta uma análise dos fenômenos que influenciam o processo de desidratação de lodo anaeróbio, a partir de simulação de leitos de secagem. Neste sentido, são feitas considerações sobre as características e o comportamento do lodo durante cada fase da secagem. Sugere-se também, um modelo matemático para representar o processo de secagem, obtido a partir dos dados experimentais.The employment of drying beds is an excellent option for dewatering of UASB reactor discarded sludge, because of their simple operation and low construction costs. This paper presents an anaerobic sludge dewatering process analysis of the most influential phenomenon based on drying beds simulation. Therefore, some considerations were made about sludge characteristics and behavior during each dewatering stage. A mathematical model for dewatering process representation obtained from experimental data is also suggested.

  4. 电渗透/Fe-过硫酸盐氧化协同强化污泥深度脱水%Coordination of electro-osmotic and Fe-persulfate oxidation process on sewage sludge deep-dewatering

    Institute of Scientific and Technical Information of China (English)

    李亚林; 刘蕾; 张毅; 魏添; 史丹

    2016-01-01

    Dewatered sewage sludge of sewage treatment plant was studied by self-made experimental device dewatering based on electro-osmotic-advanced oxidation process which would be influenced by the dosage of persulfate, proportion of ferric salt and persulfate, voltage gradient and the thickness of dewatered sewage sludge. The results showed that the combination of electro-osmosis-advanced oxidation technology can improve the dewater ability. The water content can be reduced to below 60% with sludge amount of 140 g, persulfate dosage of 100 mg·(g DS)−1, Fe2+/persulfate of 1:1, mechanical pressure of 17.59 kPa and controlling initial voltage of 11 V·cm−1. Electro-osmotic-advanced oxidation process can ensure fully use of oxidation ability of4SO−i to improve the sludge dewater ability based on the mechanism of reduction of electric field and electronic metastasis reaction, making persulfate fully activated compared with sludge dewatering by activated persulfate. Better than the traditional electro-osmosis sludge dewatering, more amount sludge can be treated one time and sludge cake uniformity can be highly improved for the subsequent transportation and settlement.%利用电渗透和高级氧化技术,采用自制实验装置对城市污水处理厂的脱水污泥进行了脱水研究,系统研究了过硫酸盐投加量、铁盐与过硫酸盐比例、电压梯度、脱水时间和污泥厚度对污泥脱水的影响。结果表明,电渗透-高级氧化复合技术可以改善污泥的脱水性能,在污泥样品为140 g、过硫酸盐投加量为100(mg·g DS)−1、Fe2+与过硫酸盐比例为1:1、机械压力为17.59 kPa、控制初始电压为11 V·cm−1时,污泥的含水率可以降低至60%以下,与单独使用电渗透技术相比,泥饼具有更好的均匀性,便于后续的运输和安置。

  5. Ultra-fine dewatering

    Energy Technology Data Exchange (ETDEWEB)

    Patwardhan, A.; Chugh, Y.P.; Arnold, B.J.; Terblanche, A.N. [Southern Illinois University, IL (US)

    2004-12-01

    The paper assesses the results from a filter press study. They demonstrate the success of a low-cost, high-efficiency filter press for dewatering column flotation clean coal products from two coal mines. A Tecnicas Hidraulicas Filter Press and a PrepTech Inc. turbo column were used for in-plant testing at a mine extracting Illinois No. 6 seam coal and another extracting Illinois No. 5 seam coal. Based on the results, an increase in profitability of US $ 900,000 per year is projected from full-scale implementation of the technology at No. 5 seam coal mine. 6 figs.

  6. Dewatering coal gas by means of triethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    Kravets, P.D.; Zhila, N.P.; Govurun, A.A.; Skripchenko, N.P.; Kiseleva, O.I. (Yuzhniigiprogaz (USSR))

    1991-05-01

    Coal gas from the Avdeevka coking plant was dewatered using an absorption method (diethylene glycol process). Flowsheets of the dewatering system are shown. Dewatering efficiency was insufficient and resulted in increased corrosion of a pipeline used for coal gas transport. Increasing efficiency of coal gas dewatering by replacing diethylene glycol with triethylene glycol is analyzed. The dewatering system using the triethylene glycol was developed and tested on a commercial scale. Dewatering conditions were the following: coal gas pressure 1.2-1.3 MPa, temperature from 27 to 38 C, dewatering capacity 43,000-69,000 m{sup 3}/h. Moisture content in coal gas was reduced from 3.0 to 0.62-0.45 g/m{sup 3} (more than 5 times). Spraying intensity was 58-69 l/1,000 m{sup 3} gas, triethylene glycol dissolution with water was 1.5-5.0%. Content of triethylene glycol after regeneration ranged from 95 to 96%. Losses of triethylene glycol were 1.6 times lower than losses of diethylene glycol. Replacing diethylene glycol with triethylene glycol was not associated with extra investment or extra operating cost. 5 refs.

  7. EADS-Astrium Lithium Technology Experiences

    Science.gov (United States)

    Mattesco, P.

    2008-09-01

    The Lithium-ion battery has been perceived ten years ago by EADS Astrium as a very promising technology in terms of technical, industrial and cost aspects for satellite platforms with respect to NiCd and NiH2 technologies. In 2008, lithium technology is the baseline for all new spacecrafts, whatever the missions.For telecommunication satellite, since 2003, more than 18 Lithium batteries for Eurostar E3000 platform have been fully tested and integrated (with SAFT VES140S Lithium cells) up to now. 6 E3000 satellites are in orbit equipped with Lithium batteries with more than 4 years in orbit for the first E3000 satellite equipped with Lithium-ion batteries. 7 others E3000 satellites with lithium batteries are currently at various stage of production.For LEO missions (THEOS, PLEIADES…), ABSL batteries with Sony 18650 HC lithium cells will replace, on the latest LEO platform the NiCd technology. The same technology change has been also successfully done previously for scientific missions: since June 2003 for Mars Express and November 2005 for Venus Express.Associated expected system improvements (weight reduction of the battery system, easiest on ground and launch pad management, highest available energy during launch, ….) driven by specific lithium-ion technology features are today demonstrated and in orbit behaviours are as expected [1], [13].The paper will give an overview of experience of EADS-Astrium on lithium battery technology with the description (design, management, architecture) of lithium batteries used on board LEO and GEO satellites. It will give also a picture of the effort done the last ten years to reach this level of experience (test characterisation, simulation…).

  8. Soil vapor extraction with dewatering

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, N.R. [Univ. of Waterloo, Ontario (Canada)

    1996-08-01

    The physical treatment technology of soil vapor extraction (SVE) is reliable, safe, robust, and able to remove significant amounts of mass at a relatively low cost. SVE combined with a pump-and-treat system to create a dewatered zone has the opportunity to remove more mass with the added cost of treating the extracted groundwater. Various limiting processes result in a significant reduction in the overall mass removal rates from a SVE system in porous media. Only pilot scale, limited duration SVE tests conducted in low permeability media have been reported in the literature. It is expected that the presence of a fracture network in low permeability media will add another complexity to the limiting conditions surrounding the SVE technology. 20 refs., 4 figs.

  9. Dewatering studies of fine clean coal

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, B.K.

    1991-01-01

    Physical cleaning of ultra-fine coal using an advanced froth flotation technique provides a low ash product, however, the amount of water associated with clean coal is high. Economic removal of water from the froth will be important for commercial applicability of advanced froth flotation processes. The main objective of the present research program is to study and understand the dewatering characteristics of ultra-fine clean coal and to develop the process parameters to effectively reduce the moisture to less than 20 percent in the clean coal product. The research approach under investigation utilizes synergistic effects of metal ions and surfactant to lower the moisture of clean coal using a conventional vacuum dewatering technique. During the last year's effort, it was reported that a combination of metal ion and surfactant provided a 22 percent moisture filter cake.

  10. 75 FR 37339 - Airworthiness Directives; EADS CASA (Type Certificate Previously Held by Construcciones...

    Science.gov (United States)

    2010-06-29

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; EADS CASA (Type... this proposed AD, contact EADS-CASA, Military Transport Aircraft Division (MTAD), Integrated Customer...; fax +34 91 585 55 05; e-mail MTA.TechnicalService@casa.eads.net ; Internet http://www.eads.net . You...

  11. Filtration and dewatering: review of literature. [117 references

    Energy Technology Data Exchange (ETDEWEB)

    Gala, H. B.; Chiang, S. H.

    1980-09-01

    Filtration and dewatering are important aspects of any chemical process involved in producing solid product from a slurry. However, these operations are not studied in as much detail as other industrial operations like distillation, absorption, etc. In the past, the design of filtration equipment was considered more of an art than science. Only in the last few years have attempts been made to understand the fundamental mechanism underlying these operations. In this review, the present status of filtration and dewatering is discussed, particularly concerning the models used for predicting the rate of filtration and dewatering. Effects of various parameters, size of particles in the slurry, their shape and method of cake formation, etc., on the characteristics of these operations are analyzed. A separate chapter on the use of these processes in coal cleaning is included. Dewatering of fine coal and refuse has attracted a great deal of attention in recent years. Special problems associated with dewatering of fine coal are discussed. Enhanced methods of dewatering are reviewed and finally areas requiring further research are highlighted.

  12. Enhanced Brine Dewatering System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of the Enhanced Brine Dewatering System (EBDS) is to provide a scalable means of completely recovering usable water from byproducts created by reverse...

  13. Enhanced Brine Dewatering System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of the Enhanced Brine Dewatering System (EBDS) is to provide an easily scalable means of completely recovering usable water from byproducts created by...

  14. LÍNGUAS ESTRANGEIRAS, EAD E COMPLEXIDADE

    Directory of Open Access Journals (Sweden)

    Marcus Vinícius Liessem Fontana

    2012-01-01

    Full Text Available Neste artigo, buscamos apoio nas Teorias do Pensamento Complexo (Morin, 1991, 2000, 2003; Ardoino, 1995, 1998a, 1998b; Leffa, 2006b, 2009; Mariotti, 2010 para demonstrar a necessidade de uma perspectiva multidimensional ou multirreferencial quando se trata de pesquisa em Educação, sobretudo na Educação a Distância, por ser uma modalidade de ensino relativamente recente. Isso significa dizer que é preciso abordar os problemas a partir de vários ângulos, observando-os desde diferentes pontos de vista. No Curso de Licenciatura em Espanhol a Distância em que trabalhamos, temos feito isso através de diferentes projetos de pesquisa, que se interpenetram e se complementam para que possamos dar conta das múltiplas dimensões da Educação a Distância. São projetos que tratam de formação de professores para EaD, pesquisas sobre objetos de aprendizagem e ferramentas diversas encontradas na rede, inclusão de pessoas com deficiência visual por meio das tecnologias etc. É sobre esses projetos que explicamos aqui.

  15. Osmotic Effects in Sludge Dewatering

    DEFF Research Database (Denmark)

    Keiding, Kristian; Rasmussen, Michael R.

    2003-01-01

    A model of filtration dewatering is presented. The model is based on the d’Arcy flow equation in which the resistance to filtration is described by the Corzeny–Carman equation and the driving force is the difference between the external pressure and the osmotic pressure of the filter cake. It has...... been found that this model reproduces all known features of filtration dewatering and is found to be consistent with experimental data....

  16. Dewatering studies of fine clean coal. Annual technical report, September 1, 1990--August 31, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, B.K.

    1991-12-31

    The main objective of the present research program is to study and understand dewatering characteristics of ultrafine clean coal obtained using the advanced column flotation technique from the Kerr-McGee`s Galatia preparation plant fine coal waste stream. It is also the objective of the research program to utilize the basic study results, i.e., surface chemical, particle shape particle size distribution, etc., in developing a cost-effective dewatering method. The ultimate objective is to develop process criteria to obtain a dewatered clean coal product containing less that 20 percent moisture, using the conventional vacuum dewatering equipment. (VC)

  17. Electroosmotic dewatering of dredged sediments: bench-scale investigation.

    Science.gov (United States)

    Reddy, Krishna R; Urbanek, Adam; Khodadoust, Amid P

    2006-01-01

    The Indiana Harbor (Indiana, USA) has not been dredged since 1972 due to lack of a suitable disposal site for dredged sediment. As a result of this, over a million cubic yards of highly contaminated sediment has accumulated in the harbor. Recently, the United States Army Corps of Engineers (USACE) has selected a site for the confined disposal facility (CDF) and is in the process of designing it. Although dredging can be accomplished rapidly, the disposal in the CDF has to be done slowly to allow adequate time for consolidation to occur. The sediment possesses very high moisture content and very low hydraulic conductivity, which cause consolidation to occur slowly. Consolidation of the sediment is essential in order to achieve adequate shear strength of sediments and also to provide enough air space to accommodate the large amount of sediment that requires disposal. Currently, it has been estimated that if a one 3-foot (0.9-m) thick layer of sediment was disposed of at the CDF annually, it would take approximately 10 years to dispose of all the sediment that is to be dredged from the Indiana Harbor. This study investigated the feasibility of using an electroosmotic dewatering technology to accelerate dewatering and consolidation of sediment, thereby allowing more rapid disposal of sediment into the CDF. Electroosmotic dewatering essentially involves applying a small electric potential across the sediment layer, thereby inducing rapid flow as a result of physico-chemical and electrochemical processes. A series of bench-scale electrokinetic experiments were conducted on actual dredged sediment samples from the Indiana Harbor to investigate dewatering rates caused by gravity alone, dewatering rates caused by gravity and electric potential, and the effects of the addition of polymer flocculants on dewatering of the sediments. The results showed that electroosmotic dewatering under an applied electric potential of 1.0VDC/cm could increase the rate of dewatering and

  18. Electrokinetic dewatering of ultrafine coal and coal tailings

    Energy Technology Data Exchange (ETDEWEB)

    Andy Fourie [University of Western Australia, WA (Australia). CSIRO

    2008-03-15

    There are a number of established technologies for reducing the water content of coal slurries before impounding the slurry. This report deals with the process of electrokinetic dewatering, whereby water is extracted from a slurry through the application of direct current voltage using two or more electrodes. Water flows towards the negatively charged electrode, the cathode, where it can be collected. This project sought to verify that the findings of work carried out about two decades ago on coal tailings was valid when conductive polymer electrodes (commonly known as EKGs - ElectroKinetic Geosynthetics) are used. Verify the applicability of electrokinetic dewatering to a range of ultrafine coal products and coal tailings; and characterise the dewatering efficiency and effectiveness and consequent potential economic benefits for different electrokinetic treatment regimes for both in-situ and in-process dewatering methods using EKGs. The current project has again proved the technical viability of dewatering ultrafine coal tailings electrokinetically. Before the technology can be adopted at full scale, however, it would be important to conduct field trials.

  19. Electrical field: a historical review of its application and contributions in wastewater sludge dewatering.

    Science.gov (United States)

    Mahmoud, Akrama; Olivier, Jérémy; Vaxelaire, Jean; Hoadley, Andrew F A

    2010-04-01

    Electric field-assisted dewatering, also called electro-dewatering, is a technology in which a conventional dewatering mechanism such a pressure dewatering is combined with electrokinetic effects to realize an improved liquid/solids separation, to increase the final dry solids content and to accelerate the dewatering process with low energy consumption compared to thermal drying. Electro-dewatering is not a new idea, but the practical industrial applications have been limited to niche areas in soil mechanics, civil engineering, and the ceramics industry. Recently, it has received great attention, specially, in the fields of fine-particle sludge, gelatinous sludge, sewage sludge, pharmaceutical industries, food waste and bull kelp, which could not be successfully dewatered with conventional mechanical methods. This review focuses on the scientific and practical aspects of the application of an electrical field in laboratory/industrial dewatering, and discusses this in relation to conventional dewatering techniques. A comprehensive bibliography of research in the electro-dewatering of wastewater sludges is included. As the fine-particle suspensions possess a surface charge, usually negative, they are surrounded by a layer with a higher density of positive charges, the electric double layer. When an electric field is applied, the usually negative charged particles move towards the electrode of the opposite charge. The water, commonly with cations, is driven towards the negative electrode. Electro-dewatering thus involves the well-known phenomena of electrophoresis, electro-osmosis, and electromigration. Following a detailed outline of the role of the electric double layer and electrokinetic phenomena, an analysis of the components of applied voltage and their significance is presented from an electrochemical viewpoint. The aim of this elementary analysis is to provide a fundamental understanding of the different process variables and configurations in order to

  20. Osmotic Effects in Sludge Dewatering

    DEFF Research Database (Denmark)

    Keiding, Kristian; Rasmussen, Michael R.

    2003-01-01

    A model of filtration dewatering is presented. The model is based on the d’Arcy flow equation in which the resistance to filtration is described by the Corzeny–Carman equation and the driving force is the difference between the external pressure and the osmotic pressure of the filter cake. It has...

  1. Dewatering of fine coal using hyperbaric centrifugation

    Energy Technology Data Exchange (ETDEWEB)

    Ramazan Asmatulu; Gerald H. Luttrell; Roe-Hoan Yoon [Virginia Polytechnic Institute and State University, Blacksburg, VA (US). Center for Advanced Separation Technologies

    2005-09-01

    Many coal preparation plants are forced to discard their fine coal because of the inability of existing technologies to reduce the moisture content of this product to an acceptable level. In an effort to overcome this problem, a new mechanical dewatering method has been developed that combines centrifugation with pressure filtration. The process, which may be referred to as hyperbaric centrifugation, is capable of producing a drier product than can be achieved using either filtration or centrifugation alone. The test data obtained from batch experiments show that the new method can reduce cake moisture to 10% or below for many fine coal product streams.

  2. DEVELOPMENT OF DEWATERING AIDS FOR MINERALS AND COAL FINES

    Energy Technology Data Exchange (ETDEWEB)

    Roe-Hoam Yoon; Ramazan Asmatulu; Ismail Yildirim; William Jansen; Jinmig Zhang; Brad Atkinson; Jeff Havens

    2004-07-01

    MCT has developed a suite of novel dewatering chemicals (or aids) that are designed to cause a decrease in the capillary pressures of the water trapped in a filter cake by (1) decreasing the surface tension of water, (2) increasing the contact angles of the particles to be dewatered, and (3) causing the particles to coagulate, all at the same time. The decrease in capillary pressure in turn causes an increase in the rate filtration, an increase in throughput, and a decrease in pressure drop requirement for filtration. The reagents are used frequently as blends of different chemicals in order to bring about the changes in all of the process variables noted above. The minerals and coal samples tested in the present work included copper sulfide, lead sulfide, zinc sulfide, kaolin clay, talc, and silica. The laboratory-scale test work included studies of reagent types, drying cycle times, cake thickness, slurry temperature, conditioning intensity and time, solid content, and reagent dosages. To better understand the mechanisms involved, fundamental studies were also conducted. These included the measurements of the contact angles of the particles to be dewatered (which are the measures of particle hydrophobicity) and the surface tensions of the filtrates produced from dewatering tests. The results of the laboratory-scale filtration experiments showed that the use of the novel dewatering aids can reduce the moistures of the filter cake by 30 to 50% over what can be achieved using no dewatering aids. In many cases, such high levels of moisture reductions are sufficient to obviate the needs for thermal drying, which is costly and energy intensive. Furthermore, the use of the novel dewatering aids cause a substantial increase in the kinetics of dewatering, which in turn results in increased throughput. As a result of these technological advantages, the novel dewatering aids have been licensed to Nalco, which is one of the largest mining chemicals companies of the world. At

  3. The "Metrica Regni" Project: The Polish Experience of EAD

    Science.gov (United States)

    Wajs, Hubert

    2005-01-01

    The fonds of Crown Chancery Public Register ("Metrica Regni") was chosen for the pilot project to introduce Encoded Archival Description (EAD) because of its historical value, typical archival structure and existing finding aids. The rights and privileges granted by Polish kings were recorded in the Register. The oldest books in the…

  4. Method of separating and de-watering fine particles

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Roe-Hoan

    2016-12-13

    A process for cleaning and dewatering hydrophobic particulate materials is presented. The process is performed in two steps: 1) agglomeration of the hydrophobic particles in a first hydrophobic liquid/aqueous mixture; followed by 2) dispersion of the agglomerates in a second hydrophobic liquid to release the water trapped within the agglomerates along with the entrained hydrophilic particles.

  5. 78 FR 73742 - Airworthiness Directives; EADS CASA (Type Certificate Previously Held by Construcciones...

    Science.gov (United States)

    2013-12-09

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; EADS CASA (Type... airworthiness directive (AD) for certain EADS CASA (Type Certificate Previously Held by Construcciones... information identified in this proposed AD, contact EADS-CASA, Military Transport Aircraft Division (MTAD...

  6. 77 FR 5998 - Airworthiness Directives; EADS CASA (Type Certificate Previously Held by Construcciones...

    Science.gov (United States)

    2012-02-07

    ... 2011-NM-037-AD; Amendment 39-16916; AD 2012-01-04] RIN 2120-AA64 Airworthiness Directives; EADS CASA... specified products. The MCAI states: EADS-CASA received reports of engine condition control cable (Part... reduced control of the aeroplane if it occurs during flight. To address this condition, EADS-CASA has...

  7. 75 FR 68185 - Airworthiness Directives; EADS CASA (Type Certificate Previously Held by Construcciones...

    Science.gov (United States)

    2010-11-05

    ...-142-AD; Amendment 39-16494; AD 2010-23-05] RIN 2120-AA64 Airworthiness Directives; EADS CASA (Type... (CDCCL) that were, at that moment, defined in issue C of EADS-CASA document DT-0-C00-05001. That document... implementation of the revised Fuel Airworthiness Limitations contained in issue D of EADS- CASA document DT-0-C00...

  8. Treatment of petroleum contaminated soils by hot alkaline water combined with mechanical dewatering process%热碱水洗-机械脱水工艺处理石油污染土壤

    Institute of Scientific and Technical Information of China (English)

    谭蔚; 邢帅; 贡皓霜; 刘丽艳

    2016-01-01

    The treatment of petroleum contaminated soils by hot alkaline water combined with mechanical dewatering process is conducted in an oil field in China.The effect of NaOH concentration,alkaline water-oily sludge ratio and temperature on the oil-removal effect is studied.The factors affecting the filtration and dewatering performance of the petroleum contaminated soils treated by hot alkaline water,such as the types and contents flocculating agents,are also investigated.The results show that residual oil is firstly decreased and then increased with increasing the concentration of NaOH and alkaline water-oily sludge ratio.But,the increase in temperature leds to th drastical decrease in residual oil.The proper parameters for hot alkaline water treatment are 0.2% of NaOH,4:1 of alkaline water-oily sludge ratio and 80℃ of temperature.In the experiments of dewatering,the flocculation capability of AlCl3,Fe2 (SO4) 3 and PAC are strongly influenced by pH.The Ca2+ ions effectively incresase the flocculation of tiny particles by forming Ca(OH) + and Ca(OH) 2,thus greatly improving the filtration and dewatering performance.When the concentration of CaCl2 is 0.8%,the best filtration and dewatering performance can be achieved based on the filtration rate,moisture content and residual oil ratio in the petroleum contaminated soils.%采用热碱水洗-机械脱水工艺对国内某油田区的石油污染土壤进行处理.考察了热碱水洗条件(包括NaOH质量分数、液固比、洗涤温度)对含油土壤脱油效果的影响,及絮凝剂种类、质量分数对热碱水洗法处理后的含油污泥过滤脱水性能的影响.结果表明,残余油质量分数随NaOH质量分数及液固比的升高呈现先下降后上升的趋势,而随温度的升高呈现持续下降的趋势.在探究含油污泥脱水性能实验中发现铝盐及铁盐类絮凝剂对于高碱性污泥的适应性较差,而钙盐可以很好地破坏油水细砂混合层,有效地改善含油

  9. POC-scale testing of an advanced fine coal dewatering equipment/technique

    Energy Technology Data Exchange (ETDEWEB)

    Groppo, J.G.; Parekh, B.K. [Univ. of Kentucky, Lexington, KY (United States); Rawls, P. [Department of Energy, Pittsburgh, PA (United States)

    1995-11-01

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. As the contract title suggests, the main focus of the program is on proof-of-concept testing of a dewatering technique for a fine clean coal product. The coal industry is reluctant to use the advanced fine coal recovery technology due to the non-availability of an economical dewatering process. in fact, in a recent survey conducted by U.S. DOE and Battelle, dewatering of fine clean coal was identified as the number one priority for the coal industry. This project will attempt to demonstrate an efficient and economic fine clean coal slurry dewatering process.

  10. Macroinvertebrate community responses to a dewatering disturbance gradient in a restored stream

    Directory of Open Access Journals (Sweden)

    J. D. Muehlbauer

    2010-12-01

    Full Text Available Dewatering disturbances are common in aquatic systems and represent a relatively untapped field of disturbance ecology, yet studying dewatering events along gradients in non-dichotomous (i.e., wet/dry terms is often difficult. Because many stream restorations can essentially be perceived as planned hydrologic manipulations, such systems can make ideal test-cases for understanding processes of hydrological disturbance. In this study we used an experimental drawdown in a 440 ha stream/wetland restoration site to assess aquatic macroinvertebrate community responses to dewatering and subsequent rewetting. The geomorphic nature of the site and the design of the restoration allowed dewatering to occur predictably along a gradient and decoupled the hydrologic response from any geomorphic (i.e., habitat heterogeneity effects. In the absence of such heterogeneous habitat refugia, reach-scale wetted perimeter and depth conditions exerted a strong control on community structure. The community exhibited an incremental response to dewatering severity over the course of this disturbance, which was made manifest not as a change in community means but as an increase in community variability, or dispersion, at each site. The dewatering also affected inter-species abundance and distributional patterns, as dewatering and rewetting promoted alternate species groups with divergent habitat tolerances. Finally, our results indicate that rapid rewetting – analogous to a hurricane breaking a summer drought – may represent a recovery process rather than an additional disturbance and that such processes, even in newly restored systems, may be rapid.

  11. Macroinvertebrate community responses to a dewatering disturbance gradient in a restored stream

    Directory of Open Access Journals (Sweden)

    J. D. Muehlbauer

    2011-06-01

    Full Text Available Dewatering disturbances are common in aquatic systems and represent a relatively untapped field of disturbance ecology, yet studying dewatering events along gradients in non-dichotomous (i.e. wet/dry terms is often difficult. Because many stream restorations can essentially be perceived as planned hydrologic manipulations, such systems can make ideal test-cases for understanding processes of hydrological disturbance. In this study we used an experimental drawdown in a 440 ha stream/wetland restoration site to assess aquatic macroinvertebrate community responses to dewatering and subsequent rewetting. The geomorphic nature of the site and the design of the restoration allowed dewatering to occur predictably along a gradient and decoupled the hydrologic response from any geomorphic (i.e. habitat heterogeneity effects. In the absence of such heterogeneous habitat refugia, reach-scale wetted perimeter and depth conditions exerted a strong control on community structure. The community exhibited an incremental response to dewatering severity over the course of this disturbance, which was made manifest not as a change in community means but as an increase in community variability, or dispersion, at each site. The dewatering also affected inter-species abundance and distributional patterns, as dewatering and rewetting promoted alternate species groups with divergent habitat tolerances. Finally, our results indicate that rapid rewetting – analogous to a hurricane breaking a summer drought – may represent a recovery process rather than an additional disturbance and that such processes, even in newly restored systems, may be rapid.

  12. The Development of Dewatering Predictions of the Velenje Coalmine

    Directory of Open Access Journals (Sweden)

    Željko Vukelić

    2016-08-01

    Full Text Available The complex hydro-geological situation, particularly in terms of groundwater, has been a constant threat to the mining carried out at the Velenje colliery since its inception. Of particular interest to the authors are the difficulties presented to the colliery by the adjacent sand aquifers, as the water pressure within these sands directly impacts mining safety, and the aquifers themselves are most directly affected by dewatering. In order to monitor water levels and estimate dewatering at the Velenje wells, multi-layered modelling using 3D Finite Difference Method (FDM has already been carried out. However, FDM is not optimal due to its greater dependence on cell size than on water flow. In 2017 in Velenje, a series of wells will be terminated as a result of mining and mining-induced subsidence, leading to dewatering and danger of flooding. As part of a plan to address this by replacing dewatering structures, a series of drive-in filters will be implemented around the entry and exit point tunnels of a longwall face. Because FDM seems to be inadequate for purposes of optimising this process, the Finite Elements Method (FEM was applied in this case. Based on such an application of FEM, a prediction of the optimisation of drive-in filters was carried out by the authors.

  13. Crosswalking EAD: Collaboration in Archival Description

    Directory of Open Access Journals (Sweden)

    Amy McCrory

    2005-09-01

    Full Text Available Different library departments must work together, both formally and informally, in implementing encoded archival description and in repackaging descriptive information about archival collections to other formats, particularly machine-readable cataloging. The authors, one a technical services librarian and the other a special collections archivist, describe their experiences collaborating in these processes at The Ohio State University. Although other institutions may differ in their organizational structure, the authors hope to provide technical guidance, as well as a model of collaboration between archivists and technical services personnel. Careful dialogue and planning are essential to transcend the traditional divide between archival and library descriptive practices and systems.

  14. Operator assisted optimization of sludge dewatering

    DEFF Research Database (Denmark)

    Grüttner, Henrik

    1991-01-01

    On a municipal wastewater treatment plant using a decanter-centrifuge for dewatering of anaerobic digested sludge an operator assisting system for sludge dewatering was developed. The system is based on a database used to collect data on sludge properties and operational conditions which is added...... by the operator. By graphical presentation and an advisory service these data are used to support the operator in his dewatering operations and to secure a running optimization of the sludge dewatering. Evaluations show that this system is a useful tool for data collection and presentation and that the data...... collected seem to reflect the actual situation at the plant. In the future such systems are expected to be used as tools for education of operators, transfer of knowledge from one operator to another and for a continuous optimization of dewatering operations. (A)...

  15. Salmonid redd dewatering: What do we know

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C D; Neitzel, D A

    1983-11-01

    Dewatering of salmonid spawning areas causes abrupt changes in the intergravel environment that may lead to extensive losses of development phases while intergravel in redds. Information on tolerance to dewatering and the extent of physicochemical changes in the gravel during dewatering can be used to assess potential impacts and to design and implement effective mitigation methods. Studies with fall chinook salmon are summarized, and the comparisons are made with results from available literature. Potentially useful methods of mitigation are mentioned. We found that prehatch phases (cleavage eggs and embryos) can be dewatered for several successive days and survive, but posthatch phases (eleutheroembryos and alevins) usually die within 24 hours. Survival of prehatch phases during extended dewatering requires maintenance of favorable intergravel temperature and moisture levels. Elevated temperatures (up to 22/sup 0/C) can be tolerated for up to 8 hours without direct adverse effects, but freezing temperatures (/sup -/1.0/sup 0/C or below) are lethal. Dewatered gravels must remain sufficient moisture to provide near 100% humidity for egg and embryo survival. In field situations, physicochemical conditions that limit survival in dewatered gravels include residual flow, temperature, gravel size and composition, and dissolved oxygen. Biological variables such as alevin behavior and certain species characteristics also influence survival. 29 refs., 6 figs.

  16. Combined method for simultaneously dewatering and reconstituting finely divided carbonaceous material

    Science.gov (United States)

    Wen, Wu-Wey; Deurbrouck, Albert W.

    1990-01-01

    A finely-divided carbonaceous material is dewatered and reconstituted in a combined process by adding a binding agent directly into slurry of finely divided material and dewatering the material to form a cake or consolidated piece which can be hardened by drying at ambient or elevated temperatures. Alternatively, the binder often in the form of a crusting agent is sprayed onto the surface of a moist cake prior to curing.

  17. Air Pressure-Assisted Centrifugal Dewatering of Concentrated Fine Sulfide Particles

    Directory of Open Access Journals (Sweden)

    R. Asmatulu

    2011-01-01

    Full Text Available An air pressure-assisted centrifugal dewatering method was developed and used for the dewatering of concentrated finesulfide particles, such as sphalerite, galena, and chalcopyrite. This filtration method was mainly designed to increase the filtration rate during the drainage cycle and, hence, produce drier filter cakes, which in turn could reduce the cost and emission problems/concerns of thermal dryers in the preparation plants. Several dewatering parameters, including applied pressure, centrifugal force (G-force, spin time, cake thickness, and surface hydrophobization, were tested to optimize the processing conditions. Test results showed that, at higher air pressure and centrifugal force, the cake moisture reduction was more than 70%, depending on the testing conditions. As a result, it can be-concluded that the novel filtration method effectively works on the dewatering of fine particles (–150 μm.

  18. Integrated treatment of municipal sewage sludge by deep dewatering and anaerobic fermentation for biohydrogen production.

    Science.gov (United States)

    Yu, Li; Yu, Yang; Jiang, Wentian; Wei, Huangzhao; Sun, Chenglin

    2015-02-01

    The increasing sludge generated in wastewater treatment plants poses a threat to the environment. Based on the traditional processes, sludge dewatered by usual methods was further dewatered by hydraulic compression and the filtrate released was treated by anaerobic fermentation. The difficulties in sludge dewatering were associated with the existence of sludge flocs or colloidal materials. A suitable CaO dosage of 125 mg/g dry sludge (DS) could further decrease the moisture content of sludge from 82.4 to 50.9 %. The filtrate from the dewatering procedure was a potential substrate for biohydrogen production. Adding zero-valent iron (ZVI) into the anaerobic system improved the biohydrogen yield by 20 %, and the COD removal rate was lifted by 10 % as well. Meanwhile, the sludge morphology and microbial community were altered. The novel method could greatly reduce the sludge volume and successfully treated filtrate along with the conversion of organics into biohydrogen.

  19. 76 FR 65995 - Airworthiness Directives; EADS CASA (Type Certificate Previously Held by Construcciones...

    Science.gov (United States)

    2011-10-25

    ... Certificate Previously Held by Construcciones Aeronauticas, S.A.) Airplanes AGENCY: Federal Aviation.... 39.13 by adding the following new AD: EADS CASA (Type Certificate Previously Held by Construcciones... EADS CASA (Type Certificate previously held by Construcciones Aeronauticas, S.A.) Model CN-235-100,...

  20. 78 FR 49235 - Airworthiness Directives; EADS CASA (Type Certificate Previously Held by Construcciones...

    Science.gov (United States)

    2013-08-13

    ... Certificate Previously Held by Construcciones Aeron uticas, S.A.) Airplanes AGENCY: Federal Aviation... airworthiness directive (AD) for certain EADS CASA (Type Certificate Previously Held by Construcciones Aeron.... 39.13 by adding the following new AD: EADS CASA (Type Certificate Previously Held by...

  1. 深基坑降水与回灌过程的数值模拟分析%Numerical simulation analysis of dewatering and recharge process of deep foundation pits

    Institute of Scientific and Technical Information of China (English)

    黄应超; 徐杨青

    2014-01-01

    Part of the ultra-deep foundation pits have debunked confined aquifer in Wuhan area, and thegroundwater is bound to affect the excavation. So the groundwater should be effectively controlled. Taking the dewatering of deep foundation pit of Integrated Services Building of Wuhan Women and Children Health Care Center as an example the dewatering and recharge process are simulated by using Visual Modflow. The feasibility and accuracy of simulations are analyzed, and the effcienly of different recharge methods and the impact of recharge on changes in water level and ground settlement outside the deep foundation pit are studied. The results show that the recharge plays a significant role in improving water outside the deep foundation pit, and the greater the amount of recharge, the more the water level recovery. The settlement outside the deep foundation pit can be reduced by recharge, and the more the recharge amount, the more the controlled settlement.%武汉地区部分超深基坑基底已揭穿承压含水层,地下水势必对基坑开挖造成影响,必须对地下水进行有效控制。以武汉市妇女儿童医疗保健中心综合业务楼深基坑降水工程为例,对深基坑降水与回灌过程进行三维数值模拟,分析探讨了模拟的可行性及准确性,并研究了不同回灌方法的回灌效果、回灌对坑外水位变化及地面沉降的影响。结果表明:回灌对提高坑外水位有明显作用,且回灌量越大,水位恢复越多。采用坑外回灌可控制降水引起的地面沉降,且回灌量越多,能控制的沉降量也越大。

  2. Improvement Measures of Stope Filling Dewatering Process in Sanshandao Gold Mine%三山岛金矿采场充填脱水工艺改进措施

    Institute of Scientific and Technical Information of China (English)

    颜丙乾; 杨鹏; 吕文生

    2015-01-01

    采场充填脱水效果对充填体初凝时间及其短期和长期强度产生较大影响,三山岛金矿采用溢流管溢流脱水和充填挡墙的土工布渗透脱水,脱水效率不能满足现场工作要求。为此,在充填脱水理论研究的基础上,分析了影响充填脱水速度的主要因素,提出了多项充填脱水改进措施。增设竖直或倾斜的脱水管,更有效地排出充填采场中的重力水,同时避免充填料浆中细粒级颗粒堵塞脱水管。改进充填挡墙设计和滤水布的选取,避免细粒级颗粒短时间内聚集在滤水布附近,影响渗透脱水效果。设计充填管道滤水器,在充填料浆进入采空区前,过滤充填料浆中的部分自由水,提高了充填采场中料浆的浓度,减小了采场充填脱水工作量。改变矿山简单脱水方式,进一步提高采场充填脱水效率,避免影响下一步开采工作的顺利开展。%The dewatering of stope filling has a greater impact on the initial setting time of the filling body and its short-term and long-term strength. The overflow dewatering was used in Sanshandao Gold Mine by overflow tube,and penetration de-watering was used by filling retaining geotextile,but the dewatering efficiency can not meet the requirements of field work. The main influence factors of the filling dewatering rate was analyzed on the basis of theoretical research on the filling dewatering, and many improvement measures of filling dewatering are put forward. Additional vertical or inclined dewatering tubes can be used to discharge the filling gravity water more efficiently,meanwhile avoid dewatering tube clogged by the fine-sized particles in filling slurry. The improved design of filling retaining wall and selection of treatment cloth can avoid the fine-sized particles gathered near the water treatment cloth in short time which can affect penetration dewatering. The water filter of filling tube was designed to filter

  3. Evaluation of Dewatering Performance and Fractal Characteristics of Alum Sludge.

    Directory of Open Access Journals (Sweden)

    Yongjun Sun

    Full Text Available The dewatering performance and fractal characteristics of alum sludge from a drinking-water treatment plant were investigated in this study. Variations in residual turbidity of supernatant, dry solid content (DS, specific resistance to filtration (SRF, floc size, fractal dimension, and zeta potential were analyzed. Sludge dewatering efficiency was evaluated by measuring both DS and SRF. Results showed that the optimum sludge dewatering efficiency was achieved at 16 mg∙L(-1 flocculant dosage and pH 7. Under these conditions, the maximum DS was 54.6%, and the minimum SRF was 0.61 × 10(10 m∙kg(-1. Floc-size measurements demonstrated that high flocculant dosage significantly improved floc size. Correlation analysis further revealed a strong correlation between fractal dimension and floc size after flocculation. A strong correlation also existed between floc size and zeta potential, and flocculants with a higher cationic degree had a larger correlation coefficient between floc size and zeta potential. In the flocculation process, the main flocculation mechanisms involved adsorption bridging under an acidic condition, and a combination between charge neutralization and adsorption-bridging interaction under neutral and alkaline conditions.

  4. Evaluation of Dewatering Performance and Fractal Characteristics of Alum Sludge.

    Science.gov (United States)

    Sun, Yongjun; Fan, Wei; Zheng, Huaili; Zhang, Yuxin; Li, Fengting; Chen, Wei

    2015-01-01

    The dewatering performance and fractal characteristics of alum sludge from a drinking-water treatment plant were investigated in this study. Variations in residual turbidity of supernatant, dry solid content (DS), specific resistance to filtration (SRF), floc size, fractal dimension, and zeta potential were analyzed. Sludge dewatering efficiency was evaluated by measuring both DS and SRF. Results showed that the optimum sludge dewatering efficiency was achieved at 16 mg∙L(-1) flocculant dosage and pH 7. Under these conditions, the maximum DS was 54.6%, and the minimum SRF was 0.61 × 10(10) m∙kg(-1). Floc-size measurements demonstrated that high flocculant dosage significantly improved floc size. Correlation analysis further revealed a strong correlation between fractal dimension and floc size after flocculation. A strong correlation also existed between floc size and zeta potential, and flocculants with a higher cationic degree had a larger correlation coefficient between floc size and zeta potential. In the flocculation process, the main flocculation mechanisms involved adsorption bridging under an acidic condition, and a combination between charge neutralization and adsorption-bridging interaction under neutral and alkaline conditions.

  5. Evaluation of hyperbaric filtration for fine coal dewatering. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, B.K. [Univ. of Kentucky, Lexington, KY (United States); Hogg, R. [Pennsylvania State Univ., University Park, PA (United States); Fonseca, A. [CONSOL Inc. (United States)

    1996-08-15

    The main objectives of the project were to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20% moisture. The program consisted of three phases, namely Phase 1 -- Model Development, Phase 2 -- Laboratory Studies, Phase 3 -- Pilot Plant Testing. The Pennsylvania State University led efforts in Phase 1, the University of Kentucky in Phase 2, and CONSOL Inc. in Phase 3 of the program. All three organizations were involved in all the three phases of the program. The Pennsylvania State University developed a theoretical model for hyperbaric filtration systems, whereas the University of Kentucky conducted experimental studies to investigate fundamental aspects of particle-liquid interaction and application of high pressure filter in fine coal dewatering. The optimum filtration conditions identified in Phase 1 and 2 were tested in two of the CONSOL Inc. coal preparation plants using an Andritz Ruthner portable hyperbaric filtration unit.

  6. Modeling of hyperbaric filtration and dewatering of coal

    Science.gov (United States)

    Ranjan, Sushil

    Generalized models have been developed for continuous hyperbaric filtration to evaluate cake formation, filter capacity/filter area, cake dewatering, air consumption and residual cake saturation/residual cake moisture. Emphasis has been placed on cake structure as being a major controlling factor in fine coal dewatering by filtration. The effects of cake structure, as defined by the distributions of pore size and shape, have been reviewed. A simple model relating cake structure to feed particle characteristics is presented and applied to a practical case of fine coal dewatering. A binary packing model has been proposed to explain the existence of compressibility in non-compressible cakes. This model proposes an inner open-structure in the main cake, with the inner layer being compressible. The variation in the inner cake porosity with applied pressure has been used to explain the change in specific cake resistance and filter capacity (solids cake throughput). Process simulations have been conducted for a single stage and a two stage process, wherein the original feed has been split into a coarse fraction and a fine fraction (and then each fraction processed separately). The process simulations for a two stage process show a lot of promise as this leads to a lowering of the required filter area and the residual cake moisture. The required filter area increases, while the residual cake moisture decreases as the cut size for the two stage process is increased. However, the advantages of a two stage process are adversely affected by an inefficient separation process, which leads to an increased filter area and a higher residual cake moisture and the two stage process approaches a single stage process.

  7. Thresholds for Discovery: EAD Tag Analysis in ArchiveGrid, and Implications for Discovery Systems

    Directory of Open Access Journals (Sweden)

    M. Proffitt

    2013-10-01

    Full Text Available The ArchiveGrid discovery system is made up in part of an aggregation of EAD (Encoded Archival Description encoded finding aids from hundreds of contributing institutions. In creating the ArchiveGrid discovery interface, the OCLC Research project team has long wrestled with what we can reasonably do with the large (120,000+ corpus of EAD documents. This paper presents an analysis of the EAD documents (the largest analysis of EAD documents to date. The analysis is paired with an evaluation of how well the documents support various aspects of online discovery. The paper also establishes a framework for thresholds of completeness and consistency to evaluate the results. We find that, while the EAD standard and encoding practices have not offered support for all aspects of online discovery, especially in a large and heterogeneous aggregation of EAD documents, current trends suggest that the evolution of the EAD standard and the shift from retrospective conversion to new shared tools for improved encoding hold real promise for the future.

  8. Electroosmotically enhanced sludge dewatering-pilot-plant study

    CSIR Research Space (South Africa)

    Smollen, M

    1994-01-01

    Full Text Available Owing to the inherent inefficiency of dewatering equipment widely used today, the search for improved dewatering techniques has been pursued by the investigation of new innovative ideas. The main thrust of these investigations has been...

  9. Nuevas formas de aprendizaje en EAD / New learning methods on EAD

    Directory of Open Access Journals (Sweden)

    Beatriz Elena García Londoño

    2007-01-01

    a complex, systematic and organized apprenticeship process, beyond the simple memoirist associations. The process will make a pupil be able to interact within his/her environment, to give sense to the world perceived, to process information actively and to generate knowledge. As well as creating links and relations between achieved knowledge and that likely to learn; using words, symbols and meanings for the conceptual comprehension necessary to the building of propositional learning and to the construction of new signified. The former demands the development of autonomous and permanent capacities related to the learn-to-learn processes: fundamental to the metacognition ant the metapprenticeship. Within the preceding perspective, the article looks for developing the following: in distance education, rather than transmitting knowledge, learn-to-learn competences have to be constructed. The former may be grounded through the intensive use made by the contemporary societies out of the mediated on-line knowledge, which allows transmitting almost infinite volumes of information and to reduce time and space using communicative and informative technologies. It may be also grounded through the conception of educational systems which more often devote less to transmit knowledge from an uniform curriculum and find their way to lead students into the learn-to-learn path within non-school environments such us radio, phone, television or fax mediated issues, as well as television and movie images, newspapers words and icons, publicity advertising and books, and virtual, interactive and multimedia environments.

  10. Web 2.0 e EAD: riscos e possibilidades

    Directory of Open Access Journals (Sweden)

    Richard Romancini

    2010-06-01

    Full Text Available O artigo evidencia o crescimento das possibilidades de uso de tecnologias digitais associadas à chamada “web 2.0”, entre os usuários da internet. Discute a relação desse contexto com a educação mediada por tecnologias, em particular a Educação a Distância (EAD, notando que existe o paradoxal risco de que a utilização desses novos recursos reforce paradigmas educativos informacionais/reprodutivistas. Entretanto, argumenta-se que o uso reflexivo das possibilidades que surgiram no mundo digital pode favorecer a construção de espaços de diálogos na educação on-line, dando um sentido mais comunicativo/construtivista a processos de educação virtual. Por fim, nota-se que, para este cenário mais positivo, é necessário, também, que haja o desenvolvimento de competências por parte dos participantes (professores e estudantes das ações educativas no âmbito digital.

  11. REDES TECNOLÓGICAS APLICADAS EM EaD

    Directory of Open Access Journals (Sweden)

    Suélly Lima dos Santos

    2011-08-01

    Full Text Available Com o advento da internet e o aparecimento das novas tecnologias educacionais, conjunto de informações e comunicações (telefone, internet, rádio, vídeo, computador e televisão, ultrapassaram as fronteiras das quatro paredes da sala de aula, surgindo ambientes virtuais direcionadas à ampliação da participação dos serviços públicos relacionados ao ensino. À educação e à formação técnica e profissional permitiu-se o aumento da interatividade através da tecnologia, promovendo maneiras de acesso ao aluno utilizando computadores e/ou dispositivos móveis que viabiliza a Educação à Distância (EaD. Devido o grande crescimento do ensino à distância, as instituições já utilizam redes de dados para ampliar o acesso de aprendizagem. Com este espantoso aumento das redes, e da acelerada transmissão de informações aprender como elas funcionam é muito importante, além do mais usando a própria tecnologia para este fim. Como conclusão deste trabalho as mudanças relâmpadas da grande disponibilidade de dados no ambiente virtual é de enorme valia para o processo ensino-aprendizado.

  12. Stochastic Alternating Dynamics for Synchronous EAD-Like Beating Rhythms in Cultured Cardiac Myocytes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ning; ZHANG Hui-Min; LIU Zhi-Qiang; DING Xue-Li; YANG Ming-Hao; GU Hua-Guang; REN Wei

    2009-01-01

    Dissolved cardiac myocytes can couple together and generate synchronous beatings in culture. We observed a synchronized early after-depolarization(EAD)-like rhythm in cultured cardiac myocytes and reproduced the experimental observation in a network mathematical model whose dynamics are close to a Hopf bifurcation. The mechanism for this EAD-like rhythm is attributed to noised-induced stochastic alternatings between the focus and the limit cycle. These results provide novel understandings for pathological heart rhythms like the early immature beatings.

  13. Use of an electrical aerosol detector (EAD) for nanoparticle size distribution measurement

    Science.gov (United States)

    Li, Lin; Chen, Da-Ren; Tsai, Perng-Jy

    2009-01-01

    Recently, Nanoparticle Surface Area Monitor (NSAM, TSI model 3550) and EAD (EAD, TSI Model 3070A) have been commercially available to measure the integral parameters (i.e., total particle surface area and total particle length) of nanoparticles. By comparison, the configuration of the EAD or NSAM is similar to that of electrical mobility analyzer of the early generation for particle size distribution measurement. It is therefore possible to use the EAD or NSAM as a particle sizer. To realize the objective of using the EAD as a sizer, we characterized the average electrical charges of monodisperse particles passing through the EAD particle charger and ion trap set at voltages ranging from 20 to 2500 V. The average charge data collected at different ion-trap voltages were then summarized by the empirical correlation using the parameter of Z p *V, where Z p is the particle electrical mobility and V is the ion-trap voltage. A data-reduction scheme was further proposed to retrieve the size distribution of sampled particles from the EAD readout at different ion-trap voltages. In the scheme, the functional format of each mode in a number size distribution of particles was assumed as log-normal, but the number of modes in an entire size distribution is not limited. A criterion was used to best fit the simulated EAD readouts with experimental ones by varying the count median diameter (CMD), geometric standard deviation ( σ g), and total particle number ( N t ) of each mode in a particle size distribution. Experiments were performed to verify the proposed scheme.

  14. Restructuring of colloidal cakes during dewatering.

    Science.gov (United States)

    Madeline, J B; Meireles, M; Bourgerette, C; Botet, R; Schweins, R; Cabane, B

    2007-02-13

    Aqueous suspensions of aggregated silica particles have been dewatered to the point where the colloidal aggregates connect to each other and build a macroscopic network. These wet cakes have been compressed through the application of osmotic pressure. Some cakes offer a strong resistance to osmotic pressure and remain at a low volume fraction of solids; other cakes yield at low applied pressures, achieving nearly complete solid/liquid separation. We used small angle neutron scattering and transmission electron microscopy to determine the processes by which the particles move and reorganize during cake collapse. We found that these restructuring processes follow a general course composed of three stages: (1) at all scales, voids are compressed, with large voids compressed more extensively than smaller ones; the local order remains unchanged; (2) all voids with diameters in the range of 2-20 particle diameters collapse, and a few dense regions (lumps) are formed; and (3) the dense lumps build a rigid skeleton that resists further compression. Depending on the nature of interparticle bonds, some cakes jump spontaneously into stage 3 while others remain stuck in stage 1. To elucidate the relation between bond strength and compression resistance, we have constructed a numerical model of the colloidal network. In this model, particles interact through noncentral forces that are produced by springs attached to their surfaces. Networks made of bonds that break upon stretching evolve through a plastic deformation that reproduces the three stages of restructuring evidenced by the experiments. Networks made of bonds that are fragile jump into stage 3. Networks made of bonds that can be stretched without breaking evolve through elastic compression and restructure only according to stage 1.

  15. POC-SCALE TESTING OF AN ADVANCED FINE COAL DEWATERING EQUIPMENT/TECHNIQUE

    Energy Technology Data Exchange (ETDEWEB)

    X.H. Wang; J. Wiseman; D.J. Sung; D. McLean; William Peters; Jim Mullins; John Hugh; G. Evans; Vince Hamilton; Kenneth Robinette; Tim Krim; Michael Fleet

    1999-08-01

    Dewatering of ultra-fine (minus 150 {micro}m) coal slurry to less than 20% moisture is difficult using the conventional dewatering techniques. The main objective of the project was to evaluate a novel surface modification technique, which utilizes the synergistic effect of metal ions and surfactants in combination for the dewatering of ultra-fine clean-coal slurries using various dewatering techniques on a proof-of-concept (POC) scale of 0.5 to 2 tons per hour. The addition of conventional reagents and the application of coal surface modification technique were evaluated using vacuum filtration, hyperbaric (pressure) filtration, ceramic plate filtration and screen-bowl centrifuge techniques. The laboratory and pilot-scale dewatering studies were conducted using the fine-size, clean-coal slurry produced in the column flotation circuit at the Powell Mountain Coal Company, St. Charles, VA. The pilot-scale studies were conducted at the Mayflower preparation plant in St. Charles, VA. The program consisted of nine tasks, namely, Task 1--Project Work Planning, Task 2--Laboratory Testing, Task 3--Engineering Design, Task 4--Procurement and Fabrication, Task 5--Installation and Shakedown, Task 6--System Operation, Task 7--Process Evaluation, Task 8--Equipment Removal, and Task 9--Reporting.

  16. Development of an Ultra-fine Coal Dewatering Technology and an Integrated Flotation-Dewatering System for Coal Preparation Plants

    Energy Technology Data Exchange (ETDEWEB)

    Wu Zhang; David Yang; Amar Amarnath; Iftikhar Huq; Scott O' Brien; Jim Williams

    2006-12-22

    The project proposal was approved for only the phase I period. The goal for this Phase I project was to develop an industrial model that can perform continuous and efficient dewatering of fine coal slurries of the previous flotation process to fine coal cake of {approx}15% water content from 50-70%. The feasibility of this model should be demonstrated experimentally using a lab scale setup. The Phase I project was originally for one year, from May 2005 to May 2006. With DOE approval, the project was extended to Dec. 2006 without additional cost from DOE to accomplish the work. Water has been used in mining for a number of purposes such as a carrier, washing liquid, dust-catching media, fire-retardation media, temperature-control media, and solvent. When coal is cleaned in wet-processing circuits, waste streams containing water, fine coal, and noncombustible particles (ash-forming minerals) are produced. In many coal preparation plants, the fine waste stream is fed into a series of selection processes where fine coal particles are recovered from the mixture to form diluted coal fine slurries. A dewatering process is then needed to reduce the water content to about 15%-20% so that the product is marketable. However, in the dewatering process currently used in coal preparation plants, coal fines smaller than 45 micrometers are lost, and in many other plants, coal fines up to 100 micrometers are also wasted. These not-recovered coal fines are mixed with water and mineral particles of the similar particle size range and discharged to impoundment. The wasted water from coal preparation plants containing unrecoverable coal fine and mineral particles are called tailings. With time the amount of wastewater accumulates occupying vast land space while it appears as threat to the environment. This project developed a special extruder and demonstrated its application in solid-liquid separation of coal slurry, tailings containing coal fines mostly less than 50 micron. The

  17. Electroosmotically enhanced dewatering/deliquoring of fine-particle coal: Final report, January 1--December 31, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Sami, Sedat [Department of Civil Engineering and Mechanics, Southern Illinois Univ., Carbondale, IL (United States); Davis, P.hilip K. [Department of Civil Engineering and Mechanics, Southern Illinois Univ., Carbondale, IL (United States); Smith, James G. [Department of Electrical Engineering, Southern Illinois Univ., Carbondale, IL (United States)

    1989-03-01

    This research is an investigation of the use of electroosmosis to dewater/deliquor ultrafine coal. Post-beneficiation dewatering/deliquoring methods for ultrafine coal are inadequate and generally require subsequent thermal drying. Thermal drying is not only expensive and time consuming, it also does not recover liquids for reuse in beneficiation processes. The degree of difficulty associated with dewatering increases as surface forces become more important than gravimetric forces. Electroosmotic flow has advantages for dewatering because it is much less sensitive to pore size than hydraulic gradient flow for the 1 to 75 ..mu..m ultrafine size range. The first year of this project focused upon preparation of ultrafine coal samples, development of test equipment and test cells, identification of variables affecting electroosmosis, and trial runs. Techniques and procedures not previously used by researchers of electroosmotic dewatering have revealed important information about the dynamics of the electroosmosis process. The identification of the first few millimeters of the cathode region of the cell as the sink for most of the energy input into the process provides the potential for improving efficiency by concentrating the second year effort on intervention in that region. Information gathered about differences in FTIR spectra as a function of location in the dewatering cell will be investigated. Changes in pH with temperature and by the application of electroosmotic current flow will receive attention, as well. 178 refs., 16 figs.

  18. Pervaporation applied for dewatering of reaction mixture during esterification

    Directory of Open Access Journals (Sweden)

    Krasiński Andrzej

    2016-03-01

    Full Text Available In this work the esterification of diethyl tartrate was studied. The research was focused on the enhancement of reversible reaction yield, which is accomplished by dewatering of the reaction mixture. The removal of water shifts the equilibrium towards the main product. Pervaporation was applied for this purpose, and results were compared to distillation. The advantages and limitations of both processes are discussed. The experimental part consists of dewatering of mixture after the reaction had reached the equilibrium, and was subsequently fed to the test rig equipped with a single zeolite membrane purchased from Pervatech B.V. Results show a significant conversion increase as a result of water removal by pervaporation. Compared to distillation no addition of organics is necessary to efficiently remove water above the azeotrope. Nevertheless, some limitations and issues which call for optimisation are pointed out. A simple numerical model is proposed to support design and sizing of the pervaporation system. Various modes of integrated system operation are also briefly discussed.

  19. Use of geotextile tubes with chemical amendments to dewater dairy lagoon solids.

    Science.gov (United States)

    Worley, J W; Bass, T M; Vendrell, P F

    2008-07-01

    Three geo-textile filtration tubes were used to dewater lagoon solids from a first stage dairy lagoon using chemical amendments (aluminum sulfate and a polymer) to enhance the separation process. This experiment had previously been done without chemical amendment. The chemical amendments speeded the dewatering process so that filling could be accomplished sooner, and also increased the removal rate of nutrients, especially phosphorus into the solid phase. Chemically amended slurry was pumped from the lagoon into the tube with the filtered liquid seeping from the tube and returning to the lagoon. Each tube was filled five to six times at 2-5-day intervals, and then allowed to dewater for 2 weeks before sampling the solid fraction in the tube. Separation efficiency improved from 79% to 99% for phosphorous and from 92% to 100% for organic nitrogen with chemical amendment. Time required for dewatering was significantly reduced by chemical amendment. Cost for the tube was approximately $10/m(3) of recovered solids with no chemical amendment and cost including the chemicals was approximately $14/m(3) of recovered solids.

  20. Optimisation of extraction and sludge dewatering efficiencies of bio-flocculants extracted from Abelmoschus esculentus (okra).

    Science.gov (United States)

    Lee, Chai Siah; Chong, Mei Fong; Robinson, John; Binner, Eleanor

    2015-07-01

    The production of natural biopolymers as flocculants for water treatment is highly desirable due to their inherent low toxicity and low environmental footprint. In this study, bio-flocculants were extracted from Hibiscus/Abelmoschus esculentus (okra) by using a water extraction method, and the extract yield and its performance in sludge dewatering were evaluated. Single factor experimental design was employed to obtain the optimum conditions for extraction temperature (25-90 °C), time (0.25-5 h), solvent loading (0.5-5 w/w) and agitation speed (0-225 rpm). Results showed that extraction yield was affected non-linearly by all experimental variables, whilst the sludge dewatering ability was only influenced by the temperature of the extraction process. The optimum extraction conditions were obtained at 70 °C, 2 h, solvent loading of 2.5 w/w and agitation at 200 rpm. Under the optimal conditions, the extract yield was 2.38%, which is comparable to the extraction of other polysaccharides (0.69-3.66%). The bio-flocculants displayed >98% removal of suspended solids and 68% water recovery during sludge dewatering, and were shown to be comparable with commercial polyacrylamide flocculants. This work shows that bio-flocculants could offer a feasible alternative to synthetic flocculants for water treatment and sludge dewatering applications, and can be extracted using only water as a solvent, minimising the environmental footprint of the extraction process.

  1. High pressure dewatering of liquid manure; Hoejtryksafvanding af gylle

    Energy Technology Data Exchange (ETDEWEB)

    Koch, T.

    1999-08-01

    The purpose of this work is to develop a dewatering method that can dewater digested manure to a dry matter content that makes it possible to utilise the dry matter for energy production. Many tests of existing analysis methods for liquid manure. None of the mathods have shown any acceptable correlation's between the results and obtained dewatering characteristics. This project have not developed any analysis methods that can predict the mechanical behaviour of manure. But the dewatering device that has been developed works, and can dewater manure. It has been proved that it is possible to dewater digested manure up to 59-60% dry matter content in laboratory conditions. (dewatering time 10-20 minutes and a pressure of up to 61 MPa). The experiment has shown that the maximum obtainable pressure in the manure (before it escapes the dewatering chamber) is dependent of the speed of pressure increase. At more 'commercial' conditions (a total dewatering cycle time of 30-60 seconds) it is possible to obtain a dry matter content of 50-54%. Some times it is possible to obtain 58% dry matter content and 2 days later it is only possible to obtain 51% drymatter content. 2-10% of the ammonium and potassium and 20-40% of the phosphorous is found in the dry fraction. Fresh manure have been dewatered and the maximum obtainable dry matter content is approx. 25-35% at 5-15 MPa. In the second phase of the project it was decided to include an experiment of dewatering wet straw and straw coke. A technical note on this experiment is included as an appendix. (LN)

  2. RAW MATERIAL DEWATERING ELECTROMAGNETIC TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Burdo O.G.

    2012-04-01

    Full Text Available Moisture transfer schemes and mechanisms of capillary-porous materials dehydration are considered. Mechanical, thermal and diffusive mechanisms for different moisture linkage forms are analyzed, driving forces and velocity coefficients of processes are estimated. Availability of dehydration in microwave frequencies range field is shown. A new generalized complex that takes into account a specificity of micro- and nanokinetics of moisture transfer in products is proposed. The explanation of barodiffusive moisture transfer process mechanism in a product is shown. The results of experimental researches, in which specific energy of 1,9 MJ per 1 kg of removed moisture is reached, are shown. The tests results of the band dryer with microwave and infrared energy generators are presented.

  3. Numerical simulation of dewatering thick unconsolidated aquifers for safety of underground coal mining

    Institute of Scientific and Technical Information of China (English)

    HANG Yuan; ZHANG Gai-ling; YANG Guo-yong

    2009-01-01

    With an increase of mining the upper limits under unconsolidated aquifers, dewatering of the bottom aquifer of the Quaternary system has become a major method to avoid water and sand inrushes. In the 8th District of the Taiping Coal Mine in south-western Shandong province, the bottom aquifer of the Quaternary system is moderate to excellent in water-yielding capacity. The base rock above the coal seam is very thin in the concealed coal field of the Carboniferous and Permian systems. Therefore, a comprehensive dewatering plan from both the ground surface and the panel was proposed to lower the groundwater level in order to ensure mining safety. According to the hydrogeologic conditions of the 8th District, we established a numerical model so that we could simulate the groundwater flow in the dewatering process. We obtained the simulation parameters from previous data using backward modeling, such as the average coefficient of permeability of 12 m/d and the elastic storage coefficient of 0.002. From the same model, we predicted the movement of groundwater and water level variables and obtained the visible effect of the dewatering project. Despite the overburden failure during mining, no water and/or sand inrush occurred because the groundwater level in the bottom aquifer was lowered to a safe water level.

  4. Dewatering ultrafine clean coal in a T.H. filter press

    Energy Technology Data Exchange (ETDEWEB)

    A. Patwardhan; Y.P. Chugh; B.J. Arnold; A.N. Terblanche [Southern Illinois University at Carbondale, IL (United States). Department of Mining and Mineral Resources Engineering

    2006-01-15

    This study demonstrates a low-cost, high-efficiency filter press technology for dewatering minus 150 {mu}m column flotation clean coal products from two coal mines. Pilot-scale in-plant demonstration of this technology at these two locations provided stable, trouble-free operation while achieving an excellent dewatering performance at a high throughput. At one location, filter cakes with residual total moisture contents in the 20-22% range were achieved. At the other location 25-27% residual total moisture contents were achieved. At the second location, lower cake moisture content in the range of 21-25% was achieved with the use of appropriate dewatering aids. For difficult to dewater coals with higher clay contents, the innovative use of hot water during the filtration process was found to reduce cake moisture content by two to three percentage points over the baseline conditions. Engineering economic evaluations indicated that a fine coal product can be produced using column flotation and the filter press at a cost of $5.95/t (dry basis) for one mine. With appropriate blending strategies, annual profitability can be shown to increase by $0.9 million ($US) for this 1.8 Mt/year mine. For the second 2.4 Mt/year mine, annual profitability was projected to increase by $2.5 million ($US).

  5. Parameter investigation for decentralised dewatering and solar thermic drying of sludge.

    Science.gov (United States)

    Wett, B; Demattio, M; Becker, W

    2005-01-01

    The purpose of this paper is an experimental and model assisted investigation of the capabilities of a dewatering system for sewage sludge for decentralised sites. Laboratory and field tests are performed with different initial conditions and the influences of filter medium, initial height, initial total suspended solids, temperature and relative humidity are discussed. The experimental work shows the feasibility of geotextile media for dewatering high water content sewage sludge and that the textile structure is of secondary importance. The specific filter resistance of the sludge cake is found to be the most significant factor in dewatering applications. The mathematical description of the dewatering process is based on the superposition of two models, the Conventional Filtration Theory for the filtration phase and the BT-model for the drying phase. Feasibility and limits of the theoretical approach are evaluated by means of a comparison between measurements and simulated data of cyclic reloading tests. It is found that a better filtration efficiency is achieved at higher TSS and at lower initial height of the slurry layer. Due to the viscosity decrease, a higher temperature enhances not only evaporation, but also filtration rate.

  6. The Effects of Ischemia on the Ectopic Activity Induced by EADs. Computer Simulation

    Science.gov (United States)

    2007-11-02

    THE EFFECTS OF ISCHEMIA ON THE ECTOPIC ACTIVITY INDUCED BY EADs. COMPUTER SIMULATION. E. Colomar, J. Saiz, J.M. Ferrero (Jr) Laboratorio Integrado de...Number Task Number Work Unit Number Performing Organization Name(s) and Address(es) Laboratorio Integrado de Bioingeniería, Universidad Politécnica de

  7. 78 FR 7262 - Airworthiness Directives; EADS CASA (Type Certificate Previously Held by Construcciones...

    Science.gov (United States)

    2013-02-01

    ... Certificate Previously Held by Construcciones Aeron uticas, S.A.) Airplanes AGENCY: Federal Aviation... airworthiness directive (AD) for all EADS CASA (Type Certificate previously held by Construcciones Aeron uticas... previously held by Construcciones Aeron uticas, S.A.): Amendment 39- ] 17333. Docket No....

  8. 77 FR 64053 - Airworthiness Directives; EADS CASA (Type Certificate Previously Held by Construcciones...

    Science.gov (United States)

    2012-10-18

    ... Directives; EADS CASA (Type Certificate Previously Held by Construcciones Aeron uticas, S.A.) Airplanes... Held by Construcciones Aeron uticas, S.A.) Model CN-235, CN-235-100, CN-235-200, and CN-235-300... CASA (Type Certificate Previously Held by Construcciones Aeron uticas, S.A.): Docket No....

  9. 78 FR 68688 - Airworthiness Directives; EADS CASA (Type Certificate Previously Held by Construcciones...

    Science.gov (United States)

    2013-11-15

    ... Certificate Previously Held by Construcciones Aeronauticas, S.A.) Airplanes AGENCY: Federal Aviation... are adopting a new airworthiness directive (AD) for all EADS CASA (Type Certificate previously held by... Certificate Previously Held by Construcciones Aeronauticas, S.A.): Amendment 39-17657. Docket No....

  10. 78 FR 76050 - Airworthiness Directives; EADS CASA (Type Certificate Previously Held by Construcciones...

    Science.gov (United States)

    2013-12-16

    ... (Type Certificate Previously Held by Construcciones Aeron uticas, S.A.) Airplanes AGENCY: Federal... adopting a new airworthiness directive (AD) for certain EADS CASA (Type Certificate Previously Held by... previously held by Construcciones Aeron uticas, S.A.) Model C-212-CF airplanes, which were included in...

  11. Precision Dual-Aquifer Dewatering at a Low Level Radiological Cleanup in New Jersey

    Energy Technology Data Exchange (ETDEWEB)

    Gosnell, A. S.; Langman, J. W. Jr.; Zahl, H. A.; Miller, D. M.

    2002-02-27

    Cleanup of low-level radioactive wastes at the Wayne Interim Storage Site (WISS), Wayne, New Jersey during the period October, 2000 through November, 2001 required the design, installation and operation of a dual-aquifer dewatering system to support excavation of contaminated soils. Waste disposal pits from a former rare-earth processing facility at the WISS had been in contact with the water table aquifer, resulting in moderate levels of radionuclides being present in the upper aquifer groundwater. An uncontaminated artesian aquifer underlies the water table aquifer, and is a localized drinking water supply source. The lower aquifer, confined by a silty clay unit, is flowing artesian and exhibits potentiometric heads of up to 4.5 meters above grade. This high potentiometric head presented a strong possibility that unloading due to excavation would result in a ''blowout'', particularly in areas where the confining unit was < 1 meter thick. Excavation of contaminated materials w as required down to the surface of the confining unit, potentially resulting in an artesian aquifer head of greater than 8 meters above the excavation surface. Consequently, it was determined that a dual-aquifer dewatering system would be required to permit excavation of contaminated material, with the water table aquifer dewatered to facilitate excavation, and the deep aquifer depressurized to prevent a ''blowout''. An additional concern was the potential for vertical migration of contamination present in the water table aquifer that could result from a vertical gradient reversal caused by excessive pumping in the confined system. With these considerations in mind, a conceptual dewatering plan was developed with three major goals: (1) dewater the water table aquifer to control radionuclide migration and allow excavation to proceed; (2) depressurize the lower, artesian aquifer to reduce the potential for a ''blowout''; and (3

  12. Hydrophobic Dewatering of Fine Coal. Topical report, March 1, 1995-March 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, R.; Sohn, S.; Luttrell, J.; Phillips, D.

    1997-12-31

    Many advanced fine coal cleaning technologies have been developed in recent years under the auspices of the U.S. Department of Energy. However, they are not as widely deployed in industry as originally anticipated. An important reason for this problem is that the cleaned coal product is difficult to dewater because of the large surface area associated with fine particles. Typically, mechanical dewatering, such as vacuum filtration and centrifugation, can reduce the moisture to 20-35% level, while thermal drying is costly. To address this important industrial problem, Virginia Tech has developed a novel dewatering process, in which water is displaced from the surface of fine particulate materials by liquid butane. Since the process is driven by the hydrophobic interaction between coal and liquid butane, it was referred to as hydrophobic dewatering (HD). A fine coal sample with 21.4 pm median size was subjected to a series of bench-scale HD tests. It was a mid-vol bituminous coal obtained from the Microcel flotation columns operating at the Middle Fork coal preparation plant, Virginia. All of the test results showed that the HD process can reduce the moisture to substantially less than 10%. The process is sensitive to the amount of liquid butane used in the process relative to the solids concentration in the feed stream. Neither the intensity nor the time of agitation is critical for the process. Also, the process does not require long time for phase separation. Under optimal operating conditions, the moisture of the fine coal can be reduced to 1% by weight of coal.

  13. Dewatering gas wells with pneumatic pumping equipment

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, R.L.

    1973-01-01

    El Paso Natural Gas Co. has been operating pumping units on gas wells since 1964. At present, the company operates some 69 pumping units in the E. Panhandle field in Texas and the S. Erick field in Oklahoma. Of these 6 are pneumatic units and the remainder is conventional beam type units powered by gas-fueled engines or electric motors. A graphical representation of the data obtained from the El Paso wells in which various lift facilities are installed is included. These data show initial cost, maintenance cost, and lift cost per barrel of (1) gas engine beam unit; (2) electric beam unit; (3) pneumatic unit; (4) gas lift; and (5) intermitter. While not a panacea for all dewatering ills, pneumatic pumping represents an economical tool which may be applied to a wide range of conditions.

  14. Dewatering studies of fine clean coal. Technical report, September 1, 1991--November 30, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, B.K.

    1991-12-31

    Physical cleaning of ultra-fine coal using an advanced froth flotation technique provides a low ash product, however, the amount of water associated with clean coal is high. Economic removal of water from the froth will be important for commercial applicability of advanced froth flotation processes. The main objective of the present research program is to study and understand the dewatering characteristics of ultra-fine clean coal and to develop the process parameters to effectively reduce the moisture to less than 20 percent in the clean coal product. The research approach under investigation utilizes synergistic effects of metal ions and surfactant to lower the moisture of clean coal using a conventional vacuum dewatering technique. During the last year`s effort, it was reported that a combination of metal ion and surfactant provided a 22 percent moisture filter cake.

  15. Dewatering studies of fine clean coal. [Quarterly] technical report, December 1, 1991--February 29, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, B.K. [Kentucky Univ., Lexington, KY (United States). Center for Applied Energy Research

    1992-08-01

    Physical cleaning of ultra-fine coal using an advanced froth flotation techniques provides a low ash product, however, due to high surface area of particles the amount of water associated with clean coal is high. Economic removal of water from the froth will be important for commercial applicability of advanced froth flotation processes. The main objective of the present research program is to study and understand the dewatering characteristics of ultra-fine clean coal and to develop process parameters to effectively reduce the moisture to less than 20 percent in the clean coal product. The research approach under investigation utilizes synergistic effects of metal ions and surfactant to lower the moisture of clean coal using a conventional vacuum dewatering technique. The studies have identified a combination of metal ion and surfactant found to be effective in providing a 22 percent moisture filter cake.

  16. O papel do coordenador de curso como articulador do processo formativo na EAD

    Directory of Open Access Journals (Sweden)

    Shirley l Patrícia Nogueira de Castro e Almeida

    2016-09-01

    Full Text Available A proposta deste artigo é apresentar, uma breve investigação sobre, em que medida o coordenador de curso pode atuar como articulador do processo formativo na Educação Aberta a Distância (EAD. Nossa pesquisa caracterizou-se como bibliográfica, pois, fizemos levantamento, seleção, coleta e fichamento de informações referentes à temática e, ainda documental, pois tomamos como base referenciais do MEC e da UNIMONTES que norteiam e/ou definem as funções do coordenador de curso na EAD. Concluímos que, muito mais que um controlador de ações, o coordenador do curso é o elemento articulador das estratégias de construção de conhecimentos, o que exige qualificação e atualização constante.

  17. Investigation into alternative sludge conditioning prior to dewatering

    CSIR Research Space (South Africa)

    Smollen, M

    1997-01-01

    Full Text Available The principal objective of this work is to provide a more effective alternative for sludge conditioning prior to mechanical dewatering. The common use of polyelectrolytes often results in the anal cake solids concentration not sufficiently high...

  18. O tutor em EAD: papéis e atribuições

    Directory of Open Access Journals (Sweden)

    Jorge Adriano Pires Silva

    2016-02-01

    Full Text Available A proposta de reflexão feita neste trabalho diz respeito a um tema de grande repercussão atual: a Educação a Distância (EAD. Procura-se refletir aqui sobre os agentes envolvidos nessa modalidade de ensino não tão recente e que vem se expandindo muito devido, principalmente, ao avanço e modernização da tecnologia. Neste trabalho, lança-se foco aos tutores presenciais e à distância, procurando elucidar suas atribuições e relevância no contexto da EAD. Os tutores são peças fundamentais para a articulação e sucesso de todo o processo de ensino-aprendizagem nessa modalidade de ensino. A eles cabe o amparo didático, pedagógico, pessoal, crítico e tecnológico dos acadêmicos de modo virtual ou presencial. Por meio de uma pesquisa de cunho bibliográfico e exploratório, com bases fundamentadas na literatura pertinente, intenta-se analisar as ações do tutor no ambiente de aprendizagem da EAD, identificando seus papeis e entendendo sua importância no processo de ensino-aprendizagem na modalidade à distância.

  19. Caisson disease during the construction of the Eads and Brooklyn Bridges: A review.

    Science.gov (United States)

    Butler, W P

    2004-01-01

    The Eads Bridge (St. Louis) and the Brooklyn Bridge (New York City) were testing grounds for caisson construction. These caissons were enormous compressed air boxes used to build riverine piers and abutments anchoring the bridges. Caisson meant faster and cheaper construction, but there was a hidden cost---caisson disease (decompression sickness). Within caissons, workers labored at pressures as high as 55 psig and caisson disease was common. This discourse is a brief history of the caisson, a brief discussion of the illness as viewed in the mid 1800's, and an abbreviated history of the Eads and Brooklyn Bridges. It also provides a detailed description and evaluation of the observations, countermeasures, and recommendations of Dr. Alphonse Jaminet, the Eads Bridge physician, and Dr. Andrew Smith, the Brooklyn Bridge physician, who published reports of their experience in 1871 and 1873, respectively. These and other primary sources permit a detailed examination of early caisson disease and Jaminet's and Smith's thinking also serve as good examples from which to study and learn.

  20. A Case Study on Stratified Settlement and Rebound Characteristics due to Dewatering in Shanghai Subway Station

    Directory of Open Access Journals (Sweden)

    Jianxiu Wang

    2013-01-01

    Full Text Available Based on the Yishan Metro Station Project of Shanghai Metro Line number 9, a centrifugal model test was conducted to investigate the behavior of stratified settlement and rebound (SSR of Shanghai soft clay caused by dewatering in deep subway station pit. The soil model was composed of three layers, and the dewatering process was simulated by self-invention of decompressing devise. The results indicate that SSR occurs when the decompression was carried out, and only negative rebound was found in sandy clay, but both positive and negative rebound occurred in the silty clay, and the absolute value of rebound in sandy clay was larger than in silty clay, and the mechanism of SSR was discussed with mechanical sandwich model, and it was found that the load and cohesive force of different soils was the main source of different responses when decompressed.

  1. Vibrating membrane filtration as improved technology for microalgae dewatering.

    Science.gov (United States)

    Nurra, Claudia; Clavero, Ester; Salvadó, Joan; Torras, Carles

    2014-04-01

    The effect of shear-enhanced filtration by vibratory process in microalgae dewatering is presented in this paper. The aim of this research was to investigate the technical performance and improvement of vibrating membrane filtration compared with conventional tangential cross-flow filtration in microalgae concentration. An industrial-scale available commercial set-up was used. Several membrane materials as polyethersulfone, polyacrylonitrile, etc., and mean pore sizes (from 7000Da to 0.2μm) were tested and compared in both filtration set-ups. Experiments were carried-out with Nannochloropsis gaditana and Phaeodactylum tricornutum microalgae. It has been demonstrated that, even if the choice of the membrane depends on its cut-off, its material and the type of microalgae filtrated, dynamic filtration is always the best technology over a conventional one. If with conventional filtration permeability values were in the vicinity of 10L/h/m(2)/bar in steady state phase, with dynamic filtration these values increased to 30L/h/m(2)/bar or more.

  2. Prediction and verification of centrifugal dewatering of P. pastoris fermentation cultures using an ultra scale-down approach.

    Science.gov (United States)

    Lopes, A G; Keshavarz-Moore, E

    2012-08-01

    Recent years have seen a dramatic rise in fermentation broth cell densities and a shift to extracellular product expression in microbial cells. As a result, dewatering characteristics during cell separation is of importance, as any liquor trapped in the sediment results in loss of product, and thus a decrease in product recovery. In this study, an ultra scale-down (USD) approach was developed to enable the rapid assessment of dewatering performance of pilot-scale centrifuges with intermittent solids discharge. The results were then verified at scale for two types of pilot-scale centrifuges: a tubular bowl equipment and a disk-stack centrifuge. Initial experiments showed that employing a laboratory-scale centrifugal mimic based on using a comparable feed concentration to that of the pilot-scale centrifuge, does not successfully predict the dewatering performance at scale (P-value fermentation cultures. This work presents a simple and novel USD approach to predict dewatering levels in two types of pilot-scale centrifuges using small quantities of feedstock (<50 mL). It is a useful tool to determine optimal conditions under which the pilot-scale centrifuge needs to be operated, reducing the need for repeated pilot-scale runs during early stages of process development. Copyright © 2012 Wiley Periodicals, Inc.

  3. Electric dewatering and drying of fine-grained products; Elektrisk afvanding og toerring af finkornede produkter

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, H.K.; Villumsen, A.

    2001-07-01

    The aim of the project was to elucidate four aspects related to using electric direct current to find an energy saving alternative to existing methods within dewatering of fine-grained products. The four aspects were a) electrophoresis forced sedimentation of chalk slurry, b) electro osmotic dewatering of chalk slurry, c) electro osmotic dewatering of agricultural chalk and d) electro osmotic dewatering of liquid organic wastes. (EHS)

  4. Biodegradation and chemical precipitation of dissolved nutrients in anaerobically digested sludge dewatering centrate.

    Science.gov (United States)

    Galvagno, G; Eskicioglu, C; Abel-Denee, M

    2016-06-01

    The objective of this research was to assess specific side-stream treatment processes for biodegradation and precipitation of dissolved nutrients in dewatering centrate. In this study, characterization was made of a conventional suspended growth deammonification treatment process for transforming dissolved polyphosphate (poly-P), dissolved organic phosphorus (DOP) and dissolved organic nitrogen (DON) in two types of dewatering centrate. The deammonification process was configured as a sequencing batch reactor (SBR), combining partial nitrification and anaerobic ammonia oxidation (anammox) in a single tank. The first centrate feed studied was from the full-scale Annacis Island wastewater treatment plant (AIWWTP) located in Metro Vancouver, Canada. The second centrate feed was from a lab-scale anaerobic digester (AD) fed waste sludge from the existing City of Kelowna Wastewater Treatment Facility (KWTF), located in the Okanagan Valley, Canada. In addition, poly aluminum chloride (PACL) dosing was assessed for final polishing of dissolved nutrients. The deammonification SBR (DeSBR) process showed similar treatment characteristics for both the KWTF and AIWWTP centrates with excellent DON removal and poor non-reactive dissolved phosphorus (NRDP) removal. A statistical comparison of the DOP and poly-P through the DeSBR process suggests that DOP has a higher biodegradation potential. Future research focused on understanding the variables associated with degradation of DOP could lead to better NRDP removal through deammonification processes. Utilization of a post-anammox PACL chemical dosing stage can achieve the objective of precipitating any residual DON and NRDP and producing an effluent that has lower dissolved nutrients than the pre-digestion KWTF dewatering centrate scenario.

  5. Mechanical dewatering of silage; Mechanische Entwaesserung von Silage

    Energy Technology Data Exchange (ETDEWEB)

    Scholz, Volkhard; Daries, Werner [Leibniz-Institut fuer Agrartechnik Potsdam-Bornim e.V. (ATB), Potsdam (Germany). Abteilung Technik der Aufbereitung, Lagerung und Konservierung; Rinder, Ralf [Anhydro GmbH, Kassel (Germany)

    2009-07-01

    The use of screw presses for dewatering of silage is energetically more efficient than thermal drying. Tests with two types of screw presses show that on dry matter flow rates of more than 1.0 tDM/h the specific energy consumption is less than 30 kWh/tDM. The water content of the silage is decreased by 5 to 20 % and the share of undesired ingredients by 2 to 30 %. Besides press design and plant species, in particular moisture content, chip size and density of silage are essentially for the dewatering success. (orig.)

  6. POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report 2, January 1995--March 1995

    Energy Technology Data Exchange (ETDEWEB)

    Groppo, J.G.; Parekh, B.K.

    1995-05-05

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from January 1 to March 31, 1995.

  7. Dewatering studies of fine clean coal. Final technical report, September 1, 1991--August 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, B.K. [Kentucky Univ., Lexington, KY (United States). Center for Applied Energy Research

    1992-12-31

    Physical cleaning of ultra-fine coal using advanced froth flotation technique provides a low ash product; however, the amount of water associated with clean coal is high. Economic removal of water from the froth will be important for commercial applicability of the advanced flotation processes. The main objective of the present research program is to study and understand dewatering characteristics of ultra-fine clean coal and to develop process parameters to effectively reduce the moisture to less than 20 percent in the clean coal product. The research approach utilized synergistic effect of metal ions and surfactant addition to lower the moisture of clean coal using the conventional vacuum dewatering technique. The studies have identified a combinations of metal ions and surfactants in providing a 22 percent moisture filter cake. Surface chemical study indicated a direct correlation between the point-of-zero charge (PZC) of metal ion/fine coal system and lowering of moisture in the filter cake. Adsorption of either metal ions or surfactants alone did not provide a significant reduction of moisture in the filter cake. However, a combination of the two provided a filter cake containing about 22 percent moisture. Filtration tests conducted using a laboratory vacuum drum filter indicated that the results obtained in batch filtration could be reproduced on a continuous filtration unit. FT-IR studies indicated that anionic surfactant and metal ions form complex species which adsorbs on the fine coal and results in improved moisture reduction during filtration. Recommendations are offered for testing this novel dewatering process on a pilot scale at a coal preparation plant in Illinois.

  8. Lake Michigan Bluff Dewatering and Stabilization Study - Allegan County, Michigan

    Science.gov (United States)

    2012-09-01

    inner bar. The smooth bed features have been interpreted to represent a sand veneer over a cohesive till. Sand probing with a jet pump has verified the...dewatering system than for conventional shore protection methods such as cement seawalls, steel sheet-pile bulkheads, and stone revetments

  9. Vibratory centrifuge for the dewatering of coal sludge

    Energy Technology Data Exchange (ETDEWEB)

    Schiele, H.; Schlebusch, L.

    1981-03-03

    A vibratory centrifuge for the dewatering of coal sludge, washed small coal or slack which comprises a revolvable conical screen which has a diameter that increases towards its discharge end. The conical screen is vibratable in an axial direction and includes radial steps each having a height of at least 20 mm to rearrangement or loosen the material in the zone of each step.

  10. Groundwater Sustainability through a Novel Dewatering Technology

    Science.gov (United States)

    Jin, Y.; Holzbecher, E.; Ebneth, S.

    2012-12-01

    Groundwater plays a key role in the hydrologic cycle and ecosystem balances. Over the past decades, groundwater is intensively extracted in order to keep construction or mining sites dry. For the latter purpose the pumped water is usually discharged into a nearby surface water body or injected into an aquifer distant from the abstraction sites. As a result, aquifers are depleted and the local eco-system is disrupted as a consequence of falling groundwater tables. Given ongoing pressure on aquifer from abstraction sites, it is vital to bring up adequate attention on groundwater conservation. We demonstrate a novel technique, Düsensauginfiltration (DSI, translated as 'nozzel-suction-infiltration'), which avoids water conveyance but still lowers the groundwater table locally. The method combines abstraction of groundwater at the upper part of the aquifer with injection in the same borehole, but at a greater depth. Hence no water is withdrawn from the system. The method is already used practically in Germany, Netherlands, and China, however, it is not yet fully scientifically understood and evaluated. Currently, two tests sites in Germany, for single and multi well respectively, are selected, at which the DSI technology is currently examined. The project is cooperated with a leading dewatering company (Hoelscher Wasserbau GmbH) and funded by Deutsche Bundesstiftung Umwelt (DBU). To provide the basic principle of the method, we present numerical models solving the differential equation, which is derived from Darcy's Law and mass conservation, describing groundwater flow. We set up stationary numerical models in 2D (vertical cross section for single well case) and 3D (multi well case and/or when ambient groundwater flow is considered) using COMSOL Multiphysics. Since our model region only involves the saturated part of the unconfined aquifer, the numerical model solves a free boundary problem using hydraulic pressure as unknown variable. Two physical modes are included

  11. Fine coal dewatering enhancement using mechanical thermal techniques

    Energy Technology Data Exchange (ETDEWEB)

    Patwardhan, A.; Mondal, K.; Chugh, Y.P.; Ping, H.; Singh, N. [Southern Illinois University-Carbondale, Carbondale, IL (USA). Department of Mining & Mineral Resources Engineering

    2002-07-01

    Studies were conducted in a laboratory pressure filter to evaluate and enhance the dewatering potential of thickener underflow samples from two operating coal mines in Illinois mining the No. 6 and No. 5 seams. Physical properties such as, size distribution, zeta potential variation with pH, microstructure and particle shape and ash content were characterized. In addition cake microstructure data was obtained through scanning electron microscopy. Experiments were conducted at a pressure of 42 psig. The initial solids content was varied from 8 to 30% to determine the impact of initial solids concentration on dewatering performance. A host of chemical treatments involving different surfactants and electrolytes were evaluated. In addition, mechanical agitation of cake and hot water treatment of the slurry was attempted. The introduction of copper ions into the slurry resulted in enhanced filtration rates due to reduced specific resistance to filtrate flow and increased porosity of the cake. Use of cationic and anionic surfactants reduced the total residual moisture by over 4%. The combined effect of a surfactant and copper ion resulted in further reduction in cake moisture along with significant improvement in dewatering rates. Elevating the temperature of the slurry to 55{degree}C showed only a slight improvement in filtration rate but produced the most compact cake with the lowest moisture content. Significant improvement in the dewatering kinetics from addition of electrolytes was also observed for the Illinois No. 5 seam sample. Statistical analysis of experimental data indicates dewatering enhancements as a result of electrolyte addition, hot water treatment and mechanical agitation. 20 refs., 5 figs., 7 tabs.

  12. Dewatering studies of fine clean coal. Technical report, March 1, 1992--May 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, B.K. [Kentucky Univ., Lexington, KY (United States). Center for Applied Energy Research

    1992-10-01

    Physical cleaning of ultra-fine coal using an advanced froth flotation technique provides a low ash product, however, due to high surface area of particles the amount of water associated with clean coal is high. Economic removal of water to 20 percent or lower moisture level from the clean coal froth will be important for commercial applicability of advanced froth flotation processes. The main objective of the present research program is to study and understand the dewatering characteristics of ultra-fine clean coal and to develop process parameters to effectively reduce the moisture to less than 20 percent in the clean coal product. The research approach under investigation utilizes synergistic effect of metal ions and surfactant to lower the moisture of clean coal using a conventional vacuum dewatering technique. The studies have identified a combination of metal ions and surfactant found to be effective in providing a 22 percent moisture filter cake. During the third quarter, efforts were made to understand reagent adsorption mechanism. Adsorption studies indicated that the presence of metal ions enhanced adsorption of surfactant. It appears that metal ions induced floc formation at pH {approximately}7.0, which are hydrophilic in nature, however addition of surfactant restores the hydrophobicity. Organic polymers along with metal ions were found to be effective in dewatering of fine coal. Continuous filtration tests conducted using a drum filter provided a filter cake containing 24 percent moisture. Additional studies on mechanism of adsorption and continuous filtration using AC Electro-Coagulation will be conducted in the next quarter.

  13. Monitoring and troubleshooting of non-filamentous settling and dewatering problems in an industrial activated sludge treatment plant

    DEFF Research Database (Denmark)

    Kjellerup, B. V.; Keiding, Kristian; Nielsen, Per Halkjær

    2001-01-01

    dewaterability. The monitoring program revealed that a deterioration of the floc strength and the settling properties in the process tanks was closely connected to downstream dewatering problems and poor effluent quality. Particularly severe problems were observed a few weeks after the production at the factory...... had started after summer closedown. Possible reasons for the changes in floc properties in the process tanks were found by a) analysing change in wastewater composition by evaluating the different production lines in the industrial plant, b) evaluating the operation of the plant, and c) performing...... to characterise the changes in floc properties that led to settling and dewatering problems and to find reasons for this taking place, a comprehensive monitoring program was conducted during more than one year. The monitoring program included various measurements of floc settleability, floc strength and sludge...

  14. CONHECIMENTO-SOLIDARIEDADE COMO UM SABER DOCENTE NA MODALIDADE EAD: ATITUDES, VALORES E CONDIÇÕES

    Directory of Open Access Journals (Sweden)

    Regina Trilho Otero Xavier

    2008-07-01

    Full Text Available O presente artigo relata uma investigação que pesquisa a construção do conhecimento-solidariedade em EAD. O objetivo principal do estudo é contribuir para a implementação de ações pedagógicas em EAD na perspectiva do conhecimento-solidariedade. A partir, principalmente, dos referenciais de Boaventura Santos, Jean Piaget e Yves de La Taille procura-se compreender o que vem a ser o conhecimento-solidariedade, bem como os valores e saberes que favorecem seu desenvolvimento em ações pedagógicas de professores e alunos em EAD. Os estudos apontam que agir de acordo com o conhecimento-solidariedade exige competência cognitiva (saber ser solidário, competência afetiva (querer ser solidário e, ainda, um contexto favorável (poder ser solidário. As conclusões evidenciam que o conhecimento–solidariedade, em ações pedagógicas na modalidade EAD, está fortemente vinculado aos saberes éticos, técnicos, pedagógicos, comunicacionais e de gestão; que se trata de um saber construído progressivamente, em experiências permeadas por respeito mútuo, reciprocidade e empatia, tendo a cooperação como principal estratégia. Mas, e fundamentalmente, que a ocorrência de ações, na perspectiva do conhecimento-solidariedade, é dependente de contextos individuais de origem complexa, pois envolvem a interação de vários aspectos interligados (como: hábitos, valores, sentimentos, capacidades,... e de contextos coletivos dinâmicos (como ambientes cooperativos ou coercitivos, entre pares ou “superiores”, na presença de autoridade que incentiva ou que desfavorece a solidariedade. Palavras-chave: EaD, solidariedade, saberes docentes.

  15. Feasibility study of green wastes composting with digested and dewatering sludge from municipal wastewater treatment plant in Iran

    OpenAIRE

    Neamat Jaafarzadeh Haghighi Fard; Behnam Moradi; Mokhtar Abbasi; Rahman Alivar Babadi; Hossein Bahrani; Azadeh Mirzaie; Ahmad Zare Javid; Maryam Ravanbakhsh

    2015-01-01

    Background: Composting as a waste management technology is becoming more widespread. The purpose of this study was to assess the feasibility and to find the most effective composting process for the ratio of green waste, digested and dewatered sludge from Chonibieh wastewater treatment plant in the west region of Ahvaz. Methods: The composting time was 23 days and the evaluated parameters in this period of the study were organic carbon, total nitrogen, phosphorus, carbon to nitrogen ratio ...

  16. Membrane-based energy efficient dewatering of microalgae in biofuels production and recovery of value added co-products.

    Science.gov (United States)

    Bhave, Ramesh; Kuritz, Tanya; Powell, Lawrence; Adcock, Dale

    2012-05-15

    The objective of this paper is to describe the use of membranes for energy efficient biomass harvesting and dewatering. The dewatering of Nannochloropsis sp. was evaluated with polymeric hollow fiber and tubular inorganic membranes to demonstrate the capabilities of a membrane-based system to achieve microalgal biomass of >150 g/L (dry wt.) and ∼99% volume reduction through dewatering. The particle free filtrate containing the growth media is suitable for recycle and reuse. For cost-effective processing, hollow fiber membranes can be utilized to recover 90-95% media for recycle. Tubular membranes can provide additional media and water recovery to achieve target final concentrations. Based on the operating conditions used in this study and taking into scale-up considerations, an integrated hollow fiber-tubular membrane system can process microalgal biomass with at least 80% lower energy requirement compared to traditional processes. Backpulsing was found to be an effective flux maintenance strategy to minimize flux decline at high biomass concentration. An effective chemical cleaning protocol was developed for regeneration of fouled membranes.

  17. Synthesis, characterization and application of a novel starch-based flocculant with high flocculation and dewatering properties.

    Science.gov (United States)

    Wang, Jian-Ping; Yuan, Shi-Jie; Wang, Yi; Yu, Han-Qing

    2013-05-15

    Flocculation process is one of the most widely used techniques for water and wastewater treatment, and also for sludge dewatering. Synthesis of natural biopolymers or modification of natural biopolymers as environmentally friendly flocculants is highly desired in the field of environmental protection. In this work, a water soluble copolymer flocculant, STC-g-PDMC (starch-graft-poly (2-methacryloyloxyethyl) trimethyl ammonium chloride) was synthesized through grafting a monomer, (2-methacryloyloxyethyl) trimethyl ammonium chloride (DMC), onto starch initiated by potassium persulphate. Acetone and ethanol were used for copolymer precipitation and purification in the synthesis, which diminished the toxicity during the synthesis process. The graft copolymer was characterized using Fourier-transform infrared spectroscopy, (1)H nuclear magnetic resonance, X-ray powder diffraction, thermogravimetric analysis and elemental analysis. The prepared STC-g-PDMC exhibited a highly effective flocculation capability for kaolin suspensions compared with starch and polyacrylamide as control. The charge neutralization effect played an important role in the flocculation process at low flocculant dosages. When it was used as dewatering agent for anaerobic sludge, the conditioned sludge could be easily filtered after the dosage reached 0.696% of the dry weight of sludge. Such a graft copolymer is a promising green agent for wastewater treatment and sludge dewatering applications.

  18. Development of accelerated dewatering technology for managing oil sands fine fluid tailings

    Energy Technology Data Exchange (ETDEWEB)

    Lahaie, R. [Syncrude Canada Ltd., Fort McMurray, AB (Canada); Seto, J.T.C. [BGC Engineering Inc., Edmonton, AB (Canada); Chapman, D. [O' Kane Consultants Inc., Saskatoon, SK (Canada); Carrier, W.D. III [Argila Enterprises Inc., Lakeland, FL (United States)

    2010-07-01

    This article discussed an accelerated dewatering technique being applied and tested for managing fine fluid tailings produced from oil sands mining. The process involved rim ditching and a decant system to promote the drainage of surface waters and enhance the drying and densification of mature fine tailings (MFT). To field test the procedure, a deposit containing 60,000 cubic metres of in-line flocculated MFT was constructed and instrumented to monitor consolidation and dewatering response of the MFT deposit over time. Ten months after being filled, the deposit had settled about 1.2 metres, which corresponds to a 19 percent reduction in volume relative to initial filling. The field test will continue for several more years, during which time the deposit will continue to be monitored and sampled. The Florida phosphate industry has used rim ditching for over 20 years, but the process had never before been applied to oil sand tailings. The paper discussed the particular consolidation behaviour of MFT, the rim ditch concept, the layout of the containment pit and instrumentation, the pit filling procedure, and post-filling observations. 6 refs., 12 figs.

  19. Reducing water leakage into underground coal mines by aquifer dewatering

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, J. P.

    1978-01-01

    Based on stratigraphic, structural, hydrogeologic, and mining data collected during a study in central Pennsylvania, a two-dimensional, finite-difference computer model was used to simulate groundwater flow in a sandstone unit (0.3 to 11 m thick) overlying an underground mine, and to evaluate the responses of the flow system and leakage rate into the mine when hypothetical dewatering wells are introduced into the system. Simulation of well dewatering, using 25 wells, showed that negligible reduction in leakage would occur if sandstone permeability was less than 0.30 m/day. When sandstone permeability equalled 3.0 m/day, 25 wells reduced leakage by 2.4 percent.

  20. Chemical Dewatering Technique of waste Polymer Drilling Fluid

    Institute of Scientific and Technical Information of China (English)

    Li Gang; Zhu Muo

    1997-01-01

    @@ On the basis of the compositional analysis of waste polymer drilling fluid, we adopt chemical dewatering technique and thoroughly break down the colloid system of the drilling fluid. Having changed the surface properties of the clay particles and made the waste mud flocculate, the floc lost mud making ability and the phemeonenon of the floc returning mud is completely dispelled when it is buried. The recovered water can be reused in the mud system.

  1. Conhecimento - solidariedade como um saber docente na modalidade EAD: atitudes, valores e condições / Solidarity here know how a teaching in modalidade EAD: attitudes, values and conditions

    Directory of Open Access Journals (Sweden)

    Regina Trilho Otero Xavier

    2007-01-01

    Full Text Available O presente artigo relata uma investigação que pesquisa a construção do conhecimento-solidariedade em EaD. O objetivo principal do estudo é contribuir para a implementação de ações pedagógicas em EaD na perspectiva do conhecimentosolidariedade.A partir, principalmente, dos referenciais de Boaventura Santos, JeanPiaget e Yves de La Taille procura-se compreender o que vem a ser o conhecimentosolidariedade, bem como os valores e saberes que favorecem seu desenvolvimento em ações pedagógicas de professores e alunos em EaD. Os estudos apontam que agir de acordo com o conhecimento-solidariedade exige competência cognitiva (saber sersolidário, competência afetiva (querer ser solidário e, ainda, um contexto favorável (poder ser solidário. As conclusões evidenciam que o conhecimento–solidariedade, em ações pedagógicas na modalidade EaD, está fortemente vinculado aos saberes éticos, técnicos, pedagógicos, comunicacionais e de gestão; que se trata de um saber construído progressivamente, em experiências permeadas por respeito mútuo, reciprocidade e empatia, tendo a cooperação como principal estratégia. Mas, e fundamentalmente, que ocorrência de ações, na perspectiva do conhecimento-solidariedade, é dependente decontextos individuais de origem complexa, pois envolvem a interação de vários aspectos interligados (como: hábitos, valores, sentimentos, capacidades,... e de contextos coletivos dinâmicos (como ambientes cooperativos ou coercitivos, entre pares ou “superiores”, na presença de autoridade que incentiva ou que desfavorece a solidariedade.Abstract This article reports on an investigation that the search of knowledge-building solidarity in EaD. The main objective of the study is to contribute to the implementation of educational activities in EaD the perspective of knowledge-solidarity. From mainly on the benchmarks of Boaventura Santos, Jean Piaget and Yves de La Taille seeks to understand what has to be

  2. Investigation of Activated Sludge Sewage Dewatering by Electro-Flotation: Optimization of Operating Parameters and Energy Consumption

    Directory of Open Access Journals (Sweden)

    K. Godini

    2015-01-01

    Full Text Available Introduction & Objective: Common methods for dewatering of wastewater sludge need chemi-cals and high energy consumption and have low efficiency and environmental acceptability because of colloidal and jelly property of bacteria cells of sludge. Furthermore, their operat-ing is completely complicated. In this study electro-flotation way, as a novel method, was performed to cover these limitations and also operating parameters and energy consumptions were optimized. Materials & Methods: In order to carry out the experiments, a batch reactor with the effective volume of 450 ml was used. In this experimental- laboratorial study, the effect of pH, current density, hydraulic retention time and surface/volume changes on the amount of dewatering and the amount of total solids in both the sludge cake (dewatered sludge and the water sepa-rated from the sludge as well as the content of TSS, TS and COD in the water were investi-gated. The amount of consumed electricity was calculated and lowered by optimizing the variables. Results: The finding showed that the best efficiency (81.6% of sludge dewatering was achieved at pH = 2, current density = 1.7mA/cm2, hydraulic retention time = 30 min and sur-face/volume amount = 178 cm2/L with electrical energy consumption of 0.33-0.726 kWh/m3. Conclusion: The electro-flotation process owing to high efficiency, convenient construction and operating and lower energy consumption and construction costs compared to common methods can effectively be applied. (Sci J Hamadan Univ Med Sci 2015; 21 (4:341-349

  3. Evaluation of hyperbaric filtration for fine coal dewatering. Fourth quarterly technical progress report: June 1, 1993--September 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, B.K. [Univ. of Kentucky, Lexington, KY (United States); Hogg, R. [Pennsylvania State Univ., University Park, PA (United States); Fonseca, A. [CONSOL Inc., Library, PA (United States)

    1993-12-31

    The main objectives of the project are to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20 percent moisture. The program consist of three phases, Model Development, Laboratory Studies, and Field Testing. The Pennsylvania State University is leading efforts in Phase 1, the University of Kentucky in Phase 2, and Consol Inc. in Phase 3 of the program. All three organizations are involved in all the three phases of the program. The Pennsylvania State University is developing a theoretical model for hyperbaric filtration systems, whereas the University of Kentucky is conducting experimental studies to investigate fundamental aspects of particle-liquid interaction and application of high pressure filter in fine coal dewatering. The optimum filtration conditions identified in phase 1 and 2 will be tested in a Consol Inc. coal preparation plant using an Andritz Ruthner portable hyperbaric filtration unit.

  4. Confirmatory/release survey of the property at 71 Pearce Avenue (Former EAD Building) in Tonawanda, New York

    Energy Technology Data Exchange (ETDEWEB)

    Salame-Alfie, A.; Alibozek, R. [New York Dept. of Health, Albany, NY (United States)

    1995-12-31

    EAD Metallurgical, Inc., operated a facility in Tonawanda, New York, in which it utilized Americium 241 (Am-241) for the production of foil sources for use in smoke detectors. EAD was in operation between 1977 and 1983. By 1983, the company started losing money, and decided to relocate to Mexico. Before closing down its Tonawanda operation, however, it was required by the New York State Department of Labor (DOL) to decontaminate its facility to limits specified by DOL. No records of discharges to the sewer system were kept during this decontamination effort. Unsuccessful decontamination efforts by several EAD employees and contractors left the building contaminated, in particular the concrete floors and walls. To determine the scope of work for the decontamination project, staff from the New York State Departments of Health (DOH) and Environmental Conservation (DEC) conducted a Characterization Survey of the facility in 1993. This survey identified contamination levels of Am-241 in excess of release limits throughout the building, in the soil outside the facility, in pipes for sewage and interior drainage, and in an 8 x 8 x 11 foot sump pit in the building. DOH issued a request for proposals in early 1994 for the decontamination and subsequent decommissioning of the former EAD building, and NES/IES Inc. (NES) was awarded the contract to perform the remediation. DOH`s assignment was to provide an on-site presence to insure the completion of all agreed upon tasks, according to the terms of the contract and work plans submitted by NES. Additionally, the DOH staff acted as a liaison between NES, DOH, DEC and DOL central offices to review, comment and approve all changes or modifications to NES`s approach to the decontamination efforts. The assigned staff was also responsible for conducting confirmatory sampling and surveys of all areas deemed releasable to DOL and DEC criteria by NES.

  5. Evaluate, Analyze, Describe (EAD: Confronting Underlying Issues of Racism and Other Prejudices for Effective Intercultural Communication

    Directory of Open Access Journals (Sweden)

    Daniel Velasco

    2015-09-01

    Full Text Available Racism and other prejudices have hindered efforts to diversify and further many fields, including education, psychology, politics, law, and healthcare (Race for Opportunity, 2010. Although there are many ways to combat these prejudices, intercultural communication continues to be a vital component in assisting individuals and groups with valuing the past, understanding the present, and preparing for the future of communication in a global society (Sadri and Flammia, 2011, p. 19. This paper provides a brief overview of pertinent research and major theories related to communicating with people of different cultural backgrounds, as well as useful techniques and strategies to use when teaching in international or multinational classrooms, and working or consulting in international or multinational companies, organizations, and educational institutions. It also includes data collected via surveys and interviews that helps to shed light on underlying issues of racism and discontent in Japanese and Nigerian populations within Japan, and concludes with a description of a new approach to one of the most common intercultural communication exercises called the E.A.D. (Evaluate, Analyze, Describe. While this exercise has proved to increase cultural awareness and open the lines of communication between individuals from various cultural and lingual backgrounds, research also shows that other strategies may be necessary to achieve desired levels of communication.

  6. BIBLIOTEC: experiência do Curso de Extensão em EAD mediado por computador

    Directory of Open Access Journals (Sweden)

    Eliane L. da Silva Moro

    2003-06-01

    Full Text Available Este artigo apresenta relato de experiência do Curso BIBLIOTEC em Educação Aberta a Distância (EAD mediado por computador. O Curso teve como foco a biblioteca escolar, que exerce um papel fundamental na formação do cidadão crítico, consciente e solidário. O BIBLIOTEC desenvolveu-se através de eixos temáticos, realizando discussões e reflexões com atividades síncronas (chat e atividades assíncronas (EquiText, fórum, e-mails entre outros, na forma de Extensão, com a carga horária de 80 horas. Profissionais que atuam em bibliotecas escolares dos mais diferentes locais do Brasil e acadêmicos do Curso de Biblioteconomia e Pedagogia compartilharam um novo ambiente de aprendizado, apoiado na tecnologia da informação e da comunicação. O Curso foi ministrado pelos professores do Núcleo ECHOS/FABICO/ UFRGS. Foram utilizadas várias ferramentas auxiliando na construção colaborativa de projetos, discussões, fóruns promovendo a interação entre os participantes, proporcionando a geração de novos projetos e educação continuada.

  7. The effect of coal bed dewatering and partial oxidation on biogenic methane potential

    Science.gov (United States)

    Jones, Elizabeth J.P.; Harris, Steve H.; Barnhart, Elliott P.; Orem, William H.; Clark, Arthur C.; Corum, Margo D.; Kirshtein, Julie D.; Varonka, Matthew S.; Voytek, Mary A.

    2013-01-01

    Coal formation dewatering at a site in the Powder River Basin was associated with enhanced potential for secondary biogenic methane determined by using a bioassay. We hypothesized that dewatering can stimulate microbial activity and increase the bioavailability of coal. We analyzed one dewatered and two water-saturated coals to examine possible ways in which dewatering influences coal bed natural gas biogenesis by looking at differences with respect to the native coal microbial community, coal-methane organic intermediates, and residual coal oxidation potential. Microbial biomass did not increase in response to dewatering. Small Subunit rRNA sequences retrieved from all coals sampled represented members from genera known to be aerobic, anaerobic and facultatively anaerobic. A Bray Curtis similarity analysis indicated that the microbial communities in water-saturated coals were more similar to each other than to the dewatered coal, suggesting an effect of dewatering. There was a higher incidence of long chain and volatile fatty acid intermediates in incubations of the dewatered coal compared to the water-saturated coals, and this could either be due to differences in microbial enzymatic activities or to chemical oxidation of the coal associated with O2 exposure. Dilute H2O2 treatment of two fractions of structural coal (kerogen and bitumen + kerogen) was used as a proxy for chemical oxidation by O2. The dewatered coal had a low residual oxidation potential compared to the water-saturated coals. Oxidation with 5% H2O2 did increase the bioavailability of structural coal, and the increase in residual oxidation potential in the water saturated coals was approximately equivalent to the higher methanogenic potential measured in the dewatered coal. Evidence from this study supports the idea that coal bed dewatering could stimulate biogenic methanogenesis through partial oxidation of the structural organics in coal once anaerobic conditions are restored.

  8. Dynamics of heterogeneous separation on fine clean coal dewatering by filter press%浮选细精煤压滤脱水非均相分离动力学特性

    Institute of Scientific and Technical Information of China (English)

    巩冠群; 谢广元; 张英杰; 沙杰; 刘均章; 张秀峰; 陈宣辰; 董玉蛟

    2011-01-01

    Based on the dewatering theory and analysis of heterogeneous separation of fine clean coal dewatering, the heterogeneous separation process on fine clean coal dewatering of Yongcheng anthracite was investigated. A theoretical model on fine coal dewatering and its heterogeneous separation dynamic equations were proposed. The results show that the pressure filtration of flotation fine clean coal has the characteristic of heterogeneous separation of fluid dynamics. Fine coal dewatering rate is the function of driving force of operation, filter media,filter cake properties, coal slurry property and effective area coefficient of compaction. Pressure filtration process is comprised of filtration and pressure dewatering. The dewatering dynamic equation of flotation fine clean coal of Yongcheng anthracite was proposed. The compressibility index of cake s is 0. 855 9, the material properties constant k is 0. 237 1.%基于脱水理论及非均相分离特点分析,研究了永城无烟煤浮选细精煤脱水非均相分离过程,提出了细精煤脱水理论模型和动力学简化方程.结果表明:浮选细精煤压滤脱水具备非均相分离流体动力学作用特点,脱水速度是操作推动力、过滤介质、滤饼特性、煤浆属性及有效压密面积系数的函数,压滤过程分为过滤及压榨脱水,给出了永城无烟煤浮选细精煤过滤方程,滤饼压缩性指数s值为0.855 9,物料特性常数k为0.237 1.

  9. Locally produced natural conditioners for dewatering of faecal sludge

    Science.gov (United States)

    Gold, Moritz; Dayer, Pauline; Faye, Marie Christine Amie Sene; Clair, Guillaume; Seck, Alsane; Niang, Seydou; Morgenroth, Eberhard; Strande, Linda

    2016-01-01

    ABSTRACT In urban areas of low-income countries, treatment of faecal sludge (FS) is insufficient or non-existent. This results in large amounts of FS being dumped into the environment. Existing treatment technologies for FS, such as settling-thickening tanks and drying beds, are land intensive which is limiting in urban areas. Enhanced settling and dewatering by conditioning was evaluated in order to reduce the treatment footprint (or increase treatment capacity). Conventional wastewater conditioners, such as commercially available lime and polymers, are expensive, and commonly rely on complex supply chains for use in low-income countries. Therefore, the treatment performance of five conditioners which could be produced locally was evaluated: Moringa oleifera seeds and press cake, Jatropha curcas seeds, Jatropha Calotropis leaves and chitosan. M. oleifera seeds and press cake, and chitosan improved settling and dewatering and had a similar performance compared to lime and polymers. Optimal dosages were 400–500 kg M. oleifera/t TS, 300–800 kg lime/t TS and 25–50 kg polymer solution/t TS. In comparison, chitosan required 1.5–3.75 kg/t TS. These dosages are comparable to those recommended for wastewater (sludge). The results indicate that conditioning of FS can reduce total suspended solids (TSS) in the effluent of settling-thickening tanks by 22–81% and reduce dewatering time with drying beds by 59–97%. This means that the area of drying beds could be reduced by 59–97% with end-use as soil conditioner, or 9–26% as solid fuel. Least expensive options and availability will depend on the local context. In Dakar, Senegal, chitosan produced from shrimp waste appears to be most promising. PMID:26984372

  10. New coal dewatering technology turns sludge to powder

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-03-15

    Virginian Tech's College of Engineering's Roe-Hoan Yoon and his group have developed a hyperbaric centrifuge that can dewater coal as fine as talcum powder. Such coal fines presently must be discarded by even the most advanced coal cleaning plants because of their high moisture content. The new technology can be used with the Microcel technology to remove ash, to re-mine the fine coal discarded to impoundments and to help minimize waste generation. Virginia Tech has received $1 million in funding from the US Department of State to also help the Indian coal industry produce a cleaner product. 1 photo.

  11. 46 CFR 28.255 - Bilge pumps, bilge piping, and dewatering systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Bilge pumps, bilge piping, and dewatering systems. 28... the Aleutian Trade § 28.255 Bilge pumps, bilge piping, and dewatering systems. (a) Each vessel must be equipped with a bilge pump and bilge piping capable of draining any watertight compartment, other...

  12. STUDY OF THE DIGESTED SLUDGE DEWATERING EFFECTIVENESS USING POLYELECTROLYTE GEL BASED ON ORGANIC POLYMERS

    Directory of Open Access Journals (Sweden)

    Marcin Głodniok

    2016-02-01

    Full Text Available The paper addresses the problems connected with sewage sludge dewatering. The premise of the study was the analysis of whether there are opportunities to increase the efficiency of dewatering sludge, a relatively low-cost involving the use of innovative polymers. The authors analyzed the impact of the new type of polyelectrolyte gel on the effectiveness of dewatering sludge. Laboratory studies were carried out at polyelectrolyte dose selection and laboratory testing on the press chamber designed to simulate the actual operation of sludge dewatering system. Two different doses of polyelectrolyte were tested for dose I – 4 ml/m3 and dose II – 8 ml/m3. The conducted analysis on laboratory press showed an increase of sludge dewatering efficiency by about 2% for dose no. I and by about 13% for dose no. II, in comparison to the test without polyelectrolyte.

  13. Study on Dewatering of Activated Sludge Under Applied Electric Field%水平电场作用下活性污泥的脱水研究

    Institute of Scientific and Technical Information of China (English)

    季雪元; 王毅力; 冯晶

    2012-01-01

    通过考察水平电场作用下活性污泥的性质(pH、电导率)、絮凝调理及电场因素(电压大小、电场应用方式、极板间距)对污泥电脱水效果的影响,确定了水平电场下污泥电脱水的最佳条件.结果表明,对于本研究的活性污泥,以水平电场为驱动力进行脱水,在原始pH(6.93)、电导率=1.46 mS·cm-1的条件下污泥电脱水效果最好;投加阳离子型聚丙烯酰胺(CPAM)可以使污泥脱水率提高30%~40%,缩短达到相同电脱水效果的时间,但对电脱水率的提高不显著.水平电场施加60 min,絮凝调理后污泥的电脱水率可达83.12%,而对应的原始污泥则需要120 min才能达到75.31%的电脱水效果.延迟电场应用对污泥电脱水效果产生抑制作用.此外,本研究确定的最佳脱水条件为:CPAM投药量为9 g.kg-1,电场强度为600V·m-1,极板间距为40 mm,电场应用时间为60 min.在上述最佳条件下对活性污泥进行电脱水,其含水率从99.30%降至95.15%,脱水率可达85.33%.%For an electro-dewatering process of activated sludge(AS),the effect of pH and conductivity of AS,flocculation conditioning and operation factors of horizontal electric field(voltage magnitude,method of applying electric field and distance between plates) were investigated,and the corresponding optimum electro-dewatering conditions were also obtained.The results showed that the best electro-dewatering effect was achieved for AS without change of its pH value(6.93) and conductivity(1.46 mS·cm-1).CPAM conditioning could lead to the increase of 30%-40% in the dewatering rate and accelerate the dewatering process,whereas a slight increase in the electro-dewatering rate.The electro-dewatering rate for conditioned AS reached 83.12% during an electric field applied period of 60 minutes,while this rate for original AS could be 75.31% even the electric field applied period extended to 120 minutes.The delay of applying the electric field had

  14. Improving the effectiveness of wells for lignite mine dewatering

    Energy Technology Data Exchange (ETDEWEB)

    Rude, T.R.; Banning, A. [Aachen Univ. (Germany). Inst. of Hydrogeology; Klauder, W.; Roger, S. [Aachen Univ. (Germany). Inst. of Hydraulic Engineering and Water Resources Management; Vinzelberg, G. [RWE Power AG, Bergheim (Germany). Dept. of Water Resources Management

    2010-07-01

    Mine dewatering is an important factor in determining the economic feasibility of lignite open cast mining projects. Ochre formation is accelerated in open pit dewatering, as the wells have long filter lengths that allow for high oxygen flux into well screens, gravel packs, and the surrounding aquifer. Ochre formation can reduce the productivity of wells by an estimated 20 percent. This experimental study investigated the formation of ochre in different environments using well screens from the Rhenish lignite mining district in Germany. The influence of oxygen, iron (Fe{sup 2+}), pH, flow velocity, water composition, and microorganisms were considered. Samples from the mine were passed through an apparatus that supplied Fe{sup 2+} and filtered the formed Fe{sup 3+} oxide colloids. The oxygen- and iron-free water was then conditioned and treated with ultraviolet (UV) radiation. Results of the study showed that Fe{sup 3+} hydroxides quickly formed in the screen due to high Fe{sup 2+} concentrations. Results indicated that pH must be kept high in the deoxygenation unit in order to facilitate rapid oxygen consumption. The experimental study will be used to investigate abiotic conditions created by variations in flow velocity, Fe{sup 2+} concentrations, sulfate content and alkalinity. 7 refs., 3 figs.

  15. Application of forward osmosis on dewatering of high nutrient sludge.

    Science.gov (United States)

    Nguyen, Nguyen Cong; Chen, Shiao-Shing; Yang, Hung-Yin; Hau, Nguyen Thi

    2013-03-01

    A novel approach was designed to simultaneously apply low energy sludge dewatering and nutrient removal for activated sludge using forward osmosis (FO). In this study, the municipal wastewater sludge was spiked with different nutrient concentrations to evaluate FO dewatering performance. The results showed that sludge concentration reached 21,511 and 28,500mg/L after 28h from initial sludge concentration of 3000 and 8000mg/L with flow rate of 150mL/min. Moreover, nutrient and organic compounds in sludge solution were also successfully removed (around 96% of NH4(+)-N, 98% of PO4(3-)-P and 99% of dissolved organic carbon (DOC)) due to steric effect of FO membrane and multi barrier layer of sludge forming on membrane surface. Furthermore, the analysis from Scanning Electron Microscopy & Energy Dispersive X-ray Spectroscopy (SEM-EDS) images recorded that FO membrane was fouled by cake layer of sludge in the active layer and NaCl in the support layer.

  16. Dewatering of alumino-humic sludge: impacts of hydroxide.

    Science.gov (United States)

    Bache, D H; Papavasilopoulos, E N

    2003-08-01

    The paper draws together information on factors which influence the conditioning and dewatering behaviour of an alum sludge gained from the coagulation of a low-turbidity coloured water. A principal focus is the potential impact of aluminium hydroxide on the sludge character. Background information is provided on the composition of the source floc for the domain pH 6.0-6.5 and Al>2.0mg/l. From this, there were many pointers to the presence of Al(OH)(3)(s) within the floc. A series of comparisons were made between an alum sludge and a hydroxide suspension at a concentration equivalent to the coagulant fraction within the sludge. The parameters studied included floc size, floc density, polymer adsorption and dewatering behaviour at different time-scales. In all cases, there were strong similarities in the behaviour of the two suspensions-indicating the potential impact of the hydroxide. There was also evidence of common features being displayed by both the organic fractions and the hydroxide. It was suggested that some of the behavioural features might emanate from a common fractal structure within the source floc, the fractal dimension (approximately 1) being insensitive to composition.

  17. A FORMAÇÃO POR UM FIO: o tutor na EaD no Estado do Tocantins

    OpenAIRE

    SILVA, ângela Noleto da

    2009-01-01

    O presente estudo, intitulado A formação por fio: o tutor na EAD no Estado do Tocantins é resultado da investigação empreendida nos estudos de Mestrado em Educação ligada à Linha de Pesquisa: Formação e profissionalização docente, da Faculdade de Educação da Universidade Federal de Goiás. Este estudo tem por objetivo discutir e compreender quem são esses sujeitos denominados de tutor que atuam na formação de pedagogos na modalidade a distância no estado do Tocantins. Par...

  18. STABILIZATION OF DEWATERED SEWAGE SLUDGE BY AEROBIC COMPOSTING METHOD: USING SAWDUST AS BULKING AGENTS

    Directory of Open Access Journals (Sweden)

    A PARVARESH

    2002-12-01

    Full Text Available Introduction. Sludge production from municipal wastewater treatment plants should have quality standards before disposal in to the environment. Environmental specialists classified sewage sludge as a hazardous waste because of high organic compounds and pathogenic microorganisms. They belive that sewage should be stabilized before disposal and so composting of sewage sludge is an effective and economical method to stabilize. Sewage sludge compost could be used to improve soil structure and enrich the soil with nutrients. Methods. To evaluate the optimum conditions of aerobic compost, the mixture of dewatered sewage sludge from Isfahan municipal waste water treatment plant and sawdust as bulking agent were used. Pilot scale study were performed in Isfahan municipal waste water treatment plant. To perform this research project, the dewatered sewage sludge with humidity between 78 to 82 percent were mixed with sawdust. Turning over method of the piles with one week interval were applied to aerate the mixture. Temperature of the piles were monitored at different depths daily. Other parameters such as N, G, organic matters and pH were determined weekly. Total and fecal coli form, and salmonella were determined at the beginning and end of the composting process, also heavy metals were measured at the same time. Results. The results of this study showed that after days, temperature of the mixture reached up to 55 G, and were stabled for 15 days. Humidity, organic matter, organic carbon and GIN ratio of the mixture decreased over the period of the study, due to increasing the temperature. Also organic matter and humidity mainly decreased in thermofilic phase. The number of total and fecal coliform and also salmonella decreased to A class standards of US.EPA at the end of the operation. Discussion. The results of the study also showed that, this type of composting method is reliable, and simple to schedule, with high flexibility and low odor

  19. Intelligent Risk Assessment for Dewatering of Metro-Tunnel Deep Excavations

    Directory of Open Access Journals (Sweden)

    X. W. Ye

    2012-01-01

    Full Text Available In recent years, China has been undergoing a metro railway construction boom in order to alleviate the urban traffic congestion problem resulting from the rapid urbanization and population growth in many metropolises. In the construction of metro systems, deep excavations and continuous dewatering for construction of the metro tunnels and stations remain a challenging and high risk task in densely populated urban areas. Intelligent computational methods and techniques have exhibited the exceptional talent in dealing with the complicated problems inherent in the deep excavation and dewatering practice. In this paper, an intelligent risk assessment system for deep excavation dewatering is developed and has been applied in the project of Hangzhou Metro Line 1 which is the first metro line of the urban rapid rail transit system in Hangzhou, China. The specific characteristics and great challenges in deep excavation dewatering of the metro-tunnel airshaft of Hangzhou Metro Line 1 are addressed. A novel design method based on the coupled three-dimensional flow theory for dewatering of the deep excavation is introduced. The modularly designed system for excavation dewatering risk assessment is described, and the field observations in dewatering risk assessment of the airshaft excavation of Hangzhou Metro Line 1 are also presented.

  20. Improvement of dewatering characteristics by co-digestion of rice straw with sewage sludge.

    Science.gov (United States)

    Gu, Tingting; Yamamoto-Ikemoto, Ryoko; Tsuchiya-Nakakihara, Eri; Watanabe, Haruki; Suetsugu, Yasutaka; Yanai, Atsushi

    2016-12-01

    A continuous mesophilic co-digestion of sewage sludge and softened rice straw was conducted and the dewatering characteristics of digested sludge were evaluated by a dewatering experiment using a belt press. The digestion was operated with solid retention time (SRT) of 25 days, and the feeding ratio of sludge to rice straw was 1:0.5 (total solids base). After 129 days of stable operation, the properties of digested sludge were analysed; then five kinds of cationic coagulants were tested to select the optimal coagulants for dewatering, and two coagulants were selected and used in the dewatering experiment because of lower doses and lower moisture of sludge cakes. Sludge property analysis showed that by the addition of rice straw, the fibrous materials in the digested sludge increased remarkably and the normalized capillary suction time (CST) decreased significantly, indicating that the dewatering properties was improved. The results of dewatering experiment showed that by the addition of rice straw, specific filtration rate of digested sludge increased by 81.2% and 174.6%, respectively; water content of dewatered sludge cakes decreased by 8.2% and 13.4%, respectively. The dewaterability of digested sludge was suggested to be improved due to rice straw addition.

  1. Upgrading of brown coal by slurry-dewatering; Kattan no yuchu dassui ni yoru clean kotai nenryo no seizo

    Energy Technology Data Exchange (ETDEWEB)

    Okuma, O.; Shimizu, T.; Inoue, T.; Shigehisa, T.; Deguchi, T.; Katsushima, S. [Kobe Steel, Ltd., Kobe (Japan)

    1996-10-28

    This paper describes an outline of solid fuel production process from brown coal and the investigation results of its elemental techniques. Dried coal is produced by this process which consists of a dewatering of crushed brown coal in oil-based solvent, a solid and liquid separation of slurry, and a remained oil recovery by heating. This process is characterized by the higher thermal efficiency compared with usual drying and the restraint of spontaneous combustion of product coal. It was revealed that solid fuel with low moisture, low ash, low sulfur, and suppressed spontaneous combustion property can be produced from Australian brown coal through this process. From the comparison between kerosene and fuel oil A, it was confirmed that the oil content during dewatering was smaller and the oil recovery by heating was easier by using a solvent with lower boiling point. It was also confirmed that the spontaneous combustion property can be suppressed using small amount of asphalt by solving asphalt in the solvent and adsorbing asphalt on the surface of brown coal. From these results, low rank coals including brown coal, which are difficult to use, are expected to be used as clean coal with low ash and low sulfur through this process. 2 refs., 7 figs., 2 tabs.

  2. Feasibility study of green wastes composting with digested and dewatering sludge from municipal wastewater treatment plant in Iran

    Directory of Open Access Journals (Sweden)

    Neamat Jaafarzadeh Haghighi Fard

    2015-09-01

    Full Text Available Background: Composting as a waste management technology is becoming more widespread. The purpose of this study was to assess the feasibility and to find the most effective composting process for the ratio of green waste, digested and dewatered sludge from Chonibieh wastewater treatment plant in the west region of Ahvaz. Methods: The composting time was 23 days and the evaluated parameters in this period of the study were organic carbon, total nitrogen, phosphorus, carbon to nitrogen ratio (C/N, moisture content and pH. The C/N ratio was maintained at 30 with weight:weight ratio of 1:1, 1:2, 1:3 (digested and dewatered sludge to green waste. Results: It was observed that vessel R3 produced higher quality of compost with final total nitrogen (1.28%, final total phosphorus (0.71%, final total organic carbon (TOC (25.78% and C/N (20.65% within the 23 days of composting. While vessel R1 produced higher final total nitrogen and total phosphorus with lower amount of total coliform indicating suitable quality of composting. Therefore, the results showed that the characteristics of dewatered sludge mixed with green waste proportion of green waste significantly influenced the compost quality and process dynamics. The results also showed that the quality of final products in all the conditions was in agreement with Global Organic Textile Standard (GOTS and World Health Organization (WHO guidelines. However, the moisture content ratios were lower than the mentioned guidelines. With regards to microbial quality, all three ratios were in agreement with US Environmental Protection Agency (EPA and Iranian guidelines. Conclusion: It is suggested that the final product of composting can be safely used in farmland and green space.

  3. Using of Fine Particle to Improvement of Sludge Dewater Ability

    Directory of Open Access Journals (Sweden)

    Abdullah I. Ibrahem

    2013-04-01

    Full Text Available The main objective of this study is to compare the performance of three alternative materials used to improve dewatering of sludge produced from secondary settling tank of Mosul medical city wastewater treatment plant, those materials are Kaolin, Limestone and Clay stone.Six dry weight percentages for each alternative are used (2, 4, 6, 8, 10, 12 % from dry weight of sludge. The specific resistance to filtration (SRF was used as a criterion to compare the studied materials. Experimental results showed that SRF is 4.1×1012, 5.9×1012, 5.8×1012 m/kg when 8% additional dose were used for each of Kaolin, Limestone and Clay stone respectively, this study showed that the best alternative material studied is kaolin which achieve decreasing efficiency in SRF more than 70%.     

  4. Thermally assisted mechanical dewatering (TAMD) of suspensions of fine particles: analysis of the influence of the operating conditions using the response surface methodology.

    Science.gov (United States)

    Mahmoud, Akrama; Fernandez, Aurora; Chituchi, Toma-Mihai; Arlabosse, Patricia

    2008-08-01

    Thermally assisted mechanical dewatering (TAMD) is a new process for energy-efficient liquid/solids separation which enhances conventional-device efficiency. The main idea of this process is to supply a flow of heat in mechanical dewatering processes to favour the reduction of the liquid content. This is not a new idea but the proposed combination, especially the chosen operating conditions (temperature dewatering parameter and an excellent indicator of the extent of TAMD. In this study, a two-factor central composite rotatable design was used to establish the optimum conditions for the TAMD of suspensions of fine particles. Significant regression models, describing changes on final dry solids content with respect to independent variables, were established with regression coefficients (usually called determination coefficients), R(2), greater than 80%. Experiments were carried out on a laboratory filtration/compression cell, firstly on different compressible materials: synthetic mineral suspensions such as talc and synthetic organic suspensions such as cellulose, and then on industrial materials, such as bentonite sludge provided by Soletanche Bachy Company. Experiment showed that the extent of TAMD for a given material is particularly dependent on their physical and chemical properties but also on processing parameters.

  5. Evaluation of geotextile filtration applying coagulant and flocculant amendments for aquaculture biosolids dewatering and phosphorus removal

    Science.gov (United States)

    Wastes contained in the microscreen backwash discharged from intensive recirculating aquaculture systems were removed and dewatered in simple geotextile bag filters. Three chemical coagulation aids, (aluminum sulfate (alum), ferric chloride, and calcium hydroxide (hydrated lime)), were tested in com...

  6. Study on Deep Well Dewatering Optimization Design in Deep Foundation Pit and Engineering Application

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on analyses of the theories of groundwater unsteady flow in deep well dewatering in the deep foundation pit, Theis equations are chosen to calculate and analyze the relationship between water level drawdown of confined aquifer and dewatering duration. In order to reduce engineering cost and diminish detrimental effect on ambient surrounding, optimization design target function based on the control of confined water drawdown and four restriction requisitions based on the control of safe water level, resistance to throwing up from the bottom of foundation pit, avoiding excessively great subsidence and unequal surface subsidence are proposed. A deep well dewatering project in the deep foundation pit is optimally designed. The calculated results including confined water level drawdown and surface subsidence are in close agreement with the measured results, and the optimization design can effectively control both surface subsidence outside foundation pit and unequal subsidence as a result of dewatering.

  7. Management of dewatering areas for waterfowl: A situation assessment and long-range plan: Executive summary

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document discusses strategic actions required to retain and secure increased wildlife benefits from dewatering units on Wheeler National Wildlife Refuge and...

  8. Prevention partition for land subsidence induced by engineering dewatering in Shanghai

    Science.gov (United States)

    Wang, J. X.; Liu, X. T.; Yang, T. L.

    2015-11-01

    Land subsidence in shanghai has been found for more than 70 years. In the early years, it was mainly caused by groundwater exploitation. In recent years, engineering dewatering in shallow ground (within 90 m) has become a major source for land subsidence in the rapid urbanization course. A management partition of land subsidence induced by foundation pit dewatering for the first confined aquifer was suggested.

  9. FINITE ELEMENT NUMERICAL SIMULATION OF THREE-DIMENSIONAL SEEPAGE CONTROL FOR DEEP FOUNDATION PIT DEWATERING

    Institute of Scientific and Technical Information of China (English)

    LUO Zu-jiang; ZHANG Ying-ying; WU Yong-xia

    2008-01-01

    For deep foundation pit dewatering in the Yangtze River Delta, it is easy to make a dramatic decrease of the underground water level surrounding the dewatering area and cause land subsidence and geologic disasters. In this work, a three-dimensional finite element simulation method was applied in the forth subway of Dongjiadu tunnel repair foundation pit dewatering in Shanghai. In order to control the decrease of the underground water level around the foundation pit, the foundation pit dewatering method was used to design the optimization project of dewatering ,which was simulated under these conditions that the aquifers deposited layer by layer, the bottom of the aquifers went deep to 144.45 m, the retaining wall of foundation pit shield went deep to 65 m, the filters of the extraction wells were located between 44 m to 59 m, the water level in the deep foundation pit was decreased by 34 m, and the maximum decrease of water level outside the foundation pit was 3 m. It is shown that the optimization project and the practical case are consistent with each other. Accordingly, the three-dimensional finite element numerical simulation is the basic theory of optimization design of engineering structures of dewatering in deep foundation pit in such areas.

  10. Mining nutrients (N, K, P) from urban source-separated urine by forward osmosis dewatering.

    Science.gov (United States)

    Zhang, Jiefeng; She, Qianhong; Chang, Victor W C; Tang, Chuyang Y; Webster, Richard D

    2014-03-18

    Separating urine from domestic wastewater promotes a more sustainable municipal wastewater treatment system. This study investigated the feasibility of applying a forward osmosis (FO) dewatering process for nutrient recovery from source-separated urine under different conditions, using seawater or desalination brine as a low-cost draw solution. The filtration process with the active layer facing feed solution exhibited relatively high water fluxes up to 20 L/m(2)-h. The process also revealed relatively low rejection to neutral organic nitrogen (urea-N) in fresh urine but improved rejection of ammonium (50-80%) in hydrolyzed urine and high rejection (>90%) of phosphate, potassium in most cases. Compared to simulation based on the solution-diffusion mechanism, higher water flux and solute flux were obtained using fresh or hydrolyzed urine as the feed, which was attributed to the intensive forward nutrient permeation (i.e., of urea, ammonium, and potassium). Membrane fouling could be avoided by prior removal of the spontaneously precipitated crystals in urine. Compared to other urine treatment options, the current process was cost-effective and environmentally friendly for nutrient recovery from urban wastewater at source, yet a comprehensive life-cycle impact assessment might be needed to evaluate and optimize the overall system performance at pilot and full scale operation.

  11. The future of commercial air transport; Jan van Toor, VP within EADS Corporate Technical Office CTO, gives a look into the future of aviation; interview

    NARCIS (Netherlands)

    Van Zon, N.

    2013-01-01

    Jan van Toor spends his time at EADS Innovation Works looking into the future, designing advanced concepts and initiating research efforts to analyse the feasibility and affordability of such a project. He recently visited the Faculty of Aerospace Engineering to give a lecture, and agreed to an inte

  12. The future of commercial air transport; Jan van Toor, VP within EADS Corporate Technical Office CTO, gives a look into the future of aviation; interview

    NARCIS (Netherlands)

    Van Zon, N.

    2013-01-01

    Jan van Toor spends his time at EADS Innovation Works looking into the future, designing advanced concepts and initiating research efforts to analyse the feasibility and affordability of such a project. He recently visited the Faculty of Aerospace Engineering to give a lecture, and agreed to an inte

  13. EstratÃgias de Aprendizagem de InglÃs como LÃngua Estrangeira em EaD.

    OpenAIRE

    Francisco TarcÃzio Cavalcante Benevides Junior

    2012-01-01

    Esta pesquisa tem como objetivo estudar as estratÃgias de aprendizagem (EA) utilizadas por aprendizes de inglÃs como lÃngua estrangeira em EaD. Adotamos a conceituaÃÃo de Oxford (1990), de acordo com a qual estratÃgias sÃo ―passos tomados pelo aluno para melhorar o prÃprio aprendizado‖. As estratÃgias agrupam-se em dois grandes conjuntos â o das diretas e o das indiretas, que se subdividem em: estratÃgias de memÃria; de compensaÃÃo; estratÃgias cognitivas; metacognitivas; afetivas...

  14. Permanganate/bisulfite (PM/BS) conditioning-horizontal electro-dewatering (HED) of activated sludge: Effect of reactive Mn(III) species.

    Science.gov (United States)

    Guo, Xinxin; Wang, Yili; Wang, Dongsheng

    2017-11-01

    A novel activated sludge (AS) conditioning method through permanganate/bisulfate (PM/BS) process was proposed. The method involved a new conditioner of reactive Mn(III) intermediate. Moreover, a Mn(III) conditioning-horizontal electro-dewatering (Mn(III) C-HED) process was established to improve AS dewatering performance. Underlying mechanisms were unraveled by investigating changes in physicochemical characteristics, scanning electron microscope (SEM) morphology, and transformation of water and organic matters. The optimum dewatering conditions for Mn(III) C-HED process with the final water content of 86.94% were determined as the combination of KMnO4 0.01 mol/L AS and NaHSO3 0.05 mol/L AS at 20 V for 120 min. Results showed that Mn(III) C-HED process effectively reduced free water and bound water with the corresponding removal ratios of 51.68% and 87.62% at the anode-side as well as 36.55% and 85.08% at the cathode-side, respectively. During the PM/BS process, the produced Mn(III), Mn(2+), and MnO2 exerted chemical and physical effects on AS conditioning and dewatering. Mn(III) disintegrated extracellular polymeric substances (EPS) fractions and cells in AS, as well as induced partial bound water release. Additionally, flocculation effect induced by Mn(2+) and MnO2 skeleton building also benefited AS dewatering. AS cells were further disrupted under the effect of a horizontal electric field. Accordingly, EPS within the AS matrix was solubilized, tightly bound (TB)-EPS or loosely bound (LB)-EPS was converted to their corresponding outer EPS fractions, and AS dewaterability improved. Additionally, changes in pH and temperature at HED stage damaged the AS cells and changed the floc properties, thereby leading to easy separation of liquid and AS particles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Problems of processing alkaline coals

    Energy Technology Data Exchange (ETDEWEB)

    Kheloufi, A.; Biletskyy, V.S. [Donetsk State Technical University, Donetsk (Ukraine). Department of Coal Processing

    1999-07-01

    The desalting and use of salty coals are discussed. Various technologies are compared - desalting by water washing, desalting-hydrotransport, and desalting-agglomeration, and the dewatering process considered. 4 refs., 4 figs.

  16. Thermal conductivity characteristics of dewatered sewage sludge by thermal hydrolysis reaction.

    Science.gov (United States)

    Song, Hyoung Woon; Park, Keum Joo; Han, Seong Kuk; Jung, Hee Suk

    2014-12-01

    The purpose of this study is to quantify the thermal conductivity of sewage sludge related to reaction temperature for the optimal design of a thermal hydrolysis reactor. We continuously quantified the thermal conductivity of dewatered sludge related to the reaction temperature. As the reaction temperature increased, the dewatered sludge is thermally liquefied under high temperature and pressure by the thermal hydrolysis reaction. Therefore, the bound water in the sludge cells comes out as free water, which changes the dewatered sludge from a solid phase to slurry in a liquid phase. As a result, the thermal conductivity of the sludge was more than 2.64 times lower than that of the water at 20. However, above 200, it became 0.704 W/m* degrees C, which is about 4% higher than that of water. As a result, the change in physical properties due to thermal hydrolysis appears to be an important factor for heat transfer efficiency. Implications: The thermal conductivity of dewatered sludge is an important factor the optimal design of a thermal hydrolysis reactor. The dewatered sludge is thermally liquefied under high temperature and pressure by the thermal hydrolysis reaction. The liquid phase slurry has a higher thermal conductivity than pure water.

  17. Flotation: A promising microalgae harvesting and dewatering technology for biofuels production.

    Science.gov (United States)

    Ndikubwimana, Theoneste; Chang, Jingyu; Xiao, Zongyuan; Shao, Wenyao; Zeng, Xianhai; Ng, I-Son; Lu, Yinghua

    2016-03-01

    Microalgal biomass as renewable energy source is believed to be of great potential for reliable and sustainable biofuels production. However, microalgal biomass production is pinned by harvesting and dewatering stage thus hindering the developing and growing microalgae biotechnology industries. Flotation technology applied in mineral industry could be potentially applied in microalgae harvesting and dewatering, however substantial knowledge on different flotation units is essential. This paper presents an overview on different flotation units as promising cost-effective technologies for microalgae harvesting thus bestowing for further research in development and commercialization of microalgae based biofuels. Dispersed air flotation was found to be less energy consuming. Moreover, Jameson cell flotation and dispersed ozone flotation are believed to be energy efficient microalgae flotation approaches. Microalgae harvesting and dewatering by flotation is still at embryonic stage, therefore extended studies with the focus on life cycle assessment, sustainability of the flotation unit, optimization of the operating parameters using different algal species is imperative. Though there are a number of challenges in microalgae harvesting and dewatering, with well designed and developed cultivation, harvesting/dewatering, extraction and conversion technologies, progressively, microalgae technology will be of great potential for biological carbon sequestration, biofuels and biochemicals production.

  18. Cr and Ni recovery during bioleaching of dewatered metal-plating sludge using Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Rastegar, S O; Mousavi, S M; Shojaosadati, S A

    2014-09-01

    This study determined the optimal conditions required to attain maximum metal recovery in the bioleaching process of dewatered metal-plating sludge using Acidithiobacillus ferrooxidans (A. ferrooxidans). Adaptation of this strain was carried up to 1% (w/v) of the sample. Three factors including initial pH, initial Fe(3+) concentration and pulp density were selected as the effective factors and were optimized using a central composite design of response surface methodology. An initial pH of 1, pulp density of 9 g/l and initial Fe(3+) concentration of 1g/l were determined to be optimum values by the statistical models. The highest extractions for Cr and Ni under optimal conditions were 55.6% and 58.2%, respectively. Bioleaching kinetics was investigated using a modified shrinking core model to better understand the mechanism of the leaching reaction. The model predictions indicate that the diffusion step controlled the overall dissolution kinetics and is the rate controlling step.

  19. Strategies for Treating and Dewatering Contaminated Soils and Sediments Simultaneously - 13389

    Energy Technology Data Exchange (ETDEWEB)

    Bickford, Jody; Foote, Martin [MSE Technology Applications, Inc., 200 Technology Way, Butte, MT 59701 (United States)

    2013-07-01

    MSE Technology Applications, Inc. (MSE) was asked to perform a series of treatability studies by Global Technologies, Inc. (Global) and M{sup 2} Polymer Technologies, Inc. (M{sup 2} Polymer) using Global's metal treatment agent, Molecular Bonding System (MBS) and M{sup 2} Polymer's super-absorbent polymer, Waste Lock 770 (WL-770). The primary objective of the study was to determine if the two products could be used as a one-step treatment process to reduce the leachability of metals and de-water soils and/or sediments simultaneously. Three phases of work were performed during the treatability study. The first phase consisted of generating four bench-scale samples: two treated using only MBS and two treated using only WL- 770, each at variable concentrations. The second phase consisted of generating nine bench-scale samples that were treated using MBS and WL-770 in combination with three different addition techniques. The third phase consisted of generating four intermediate-scale samples that were treated using MBS and WL-770 simultaneously. The soils used in the treatability study were collected at the Mike Mansfield Advanced Technology Center in Butte, Montana. The collected soils were screened at 4 mesh (4.75 millimeters (mm)) to remove the coarse fraction of the soil and spiked with metallic contaminants of lead, cadmium, nickel, mercury, uranium, chromium, and zinc. (authors)

  20. Compressional rheology: A tool for understanding compressibility effects in sludge dewatering.

    Science.gov (United States)

    Stickland, Anthony D

    2015-10-01

    Water and wastewater treatment sludges exhibit compressible behaviour due to flocculation and aggregation. At a critical solids concentration called the gel point, which is as low as 1-2 v/v%, a continuous interconnected network of particles is formed that can resist an applied load. The applied load (mechanical filtration pressure or buoyancy in settling for example) must exceed the network strength in order to consolidate the network. The network strength increases with solids concentration such that the equilibrium extent of consolidation is a function of the applied load. Improved understanding of the nature of compressible suspensions can have a significant impact through optimising design and operation of sludge handling and dewatering processes. This work gives an overview of compressional rheology, which has proven to be a useful tool for describing the solid-liquid separation of compressible systems. This is followed by three examples where compressibility effects must be taken into account, namely the extraction of material properties for extremely compressible materials, consolidation and crust formation during constant rate evaporation, and the effect of bed height in thickening.

  1. Electroosmotic dewatering of chalk sludge, iron hydroxide sludge, wet fly ash and biomass sludge

    DEFF Research Database (Denmark)

    Hansen, H.K.; Christensen, Iben Vernegren; Ottosen, Lisbeth M.

    2003-01-01

    Electroosmotic dewatering has been tested in laboratory cells on four different porous materials: chalk sludge, iron hydroxide sludge, wet fly ash and biomass sludge from enzyme production. In all cases it was possible to remove water when passing electric DC current through the material. Casagra......Electroosmotic dewatering has been tested in laboratory cells on four different porous materials: chalk sludge, iron hydroxide sludge, wet fly ash and biomass sludge from enzyme production. In all cases it was possible to remove water when passing electric DC current through the material....... Casagrande's coefficients were determined for the four materials at different water contents. The experiments in this work showed that chalk could be dewatered from 40% to 79% DM (dry matter), fly ash from 75 to 82% DM, iron hydroxide sludge from 2.7 to 19% DM and biomass from 3 to 33% DM by electroosmosis...

  2. Dewatering of lignin residues from enzymatic production of ethanol; Avvattning av ligninrester fraan enzymatisk framstaellning av etanol

    Energy Technology Data Exchange (ETDEWEB)

    Sedin, Peter; Theliander, Hans [Luleaa Univ. of Technology, Luleaa (Sweden); Gren, Urban [Chalmers Univ. of Technology, Goeteborg (Sweden)

    2000-05-01

    The aim of this report is to gather knowledge of dewatering of lignin residues from ethanol production through enzymatic fermentation. A combined filtering and pressing apparatus is used for the dewatering. From the experimental data it is possible to get materials data of lignin. These data may lay the foundation for a rational choice of filtering equipment and appropriate pressing conditions.

  3. Compression dewatering of municipal activated sludge: effects of salt and pH.

    Science.gov (United States)

    Raynaud, Mickael; Vaxelaire, Jean; Olivier, Jérémy; Dieudé-Fauvel, Emilie; Baudez, Jean-Christophe

    2012-09-15

    Even after mechanical dewatering, activated sludge contains a large amount of water. Due to its composition and biological nature this material is usually highly compressible and known to be difficult to dewater. In the present work, two treatments (salt addition and pH modification) are proposed to highlight some aspects which could explain the poor dewaterability of activated sludge. Dewatering tests are carried out in a pressure-driven device in order to well examine both, filtration and compression stages. Physico-chemical parameters, such as surface charge, hydrophobicity, extracellular polymeric substances (EPS) content and filtrate turbidity are measured on the tested sludge, for a better analysis of dewatering results. The dewatering ability of the sludge is widely linked to the cohesion of the flocculated matrix and the presence of fine particles. Both treatments alter the flocculated matrix and release fine particles. The release of fine particles tends to clog both, the filter cake and the filter medium. Consequently, the filtration rate decreases due to higher resistances to the flow. On another hand, the polymeric matrix breakdown enables to release some water trapped within the floc to the bulk liquid phase and thus facilitates its removal, which tends to decrease the moisture content of the filter-cake. It also impacts the compression dewatering step. The more destroyed structures lead to less elastic cakes and thus a slower primary consolidation stage. At the opposite, the mobility of the broken aggregates within the filter-cake does not seem to be improved by size reduction (the kinetics of the secondary consolidation stage are not significantly modified).

  4. Gestión de la creatividad en entornos virtuales de aprendizaje colaborativos: un proyecto corporativo de EAD

    Directory of Open Access Journals (Sweden)

    Felipe Chibás Ortíz

    2014-07-01

    Full Text Available Se mantiene abierta en nuestros días la discusión con respecto a las metodologías más efectivas en los entornos virtuales de aprendizaje (EVA colaborativos y su verdadera contribución al desarrollo de la creatividad y la actitud innovadora en los estudiantes, particularmente en los ámbitos corporativos. Las redes sociales educativas basadas en el aprendizaje colaborativo crecen exponencialmente, y se hacen ya incontables en cualquier área del conocimiento. Sin embargo, la estimulación de la creatividad de los usuarios de los EVA en general y en el ámbito corporativo en específico, se ha convertido en un problema científico de gran importancia para las investigaciones en las Ciencias de la Educación. El presente trabajo se propone valorar la presencia de indicadores de creatividad en los estudiantes al interactuar con los entornos virtuales de enseñanza de aprendizaje colaborativo, basados en la experiencia de educación a distancia (EAD corporativa acumulada en Brasil. El método de investigación utilizado es el del estudio de caso, que permitió comparar la realización de un proyecto EAD corporativo a partir de la utilización de las TIC con un enfoque creativo y educomunicativo, con otro que también utilizó las TIC pero con una visión tradicional. Fue realizado en la empresa de consultoría y e-learning Perfectu. Los resultados obtenidos sugieren que el modelo pedagógico adoptado y la forma de utilizar las TIC son las que llevan a resultados innovadores y no las TIC por sí mismas, dado que se observó que el promedio de creatividad del grupo que trabajó bajo el patrón educomunicativo-creativo fue más elevado que para el grupo que trabajó con el paradigma tradicional.

  5. A Study of the system control model of caisson dewatering of the north anchorage of Taizhou Bridge

    Institute of Scientific and Technical Information of China (English)

    Zhao Yanrong; Zhou Zhifang; Ruan Jing

    2011-01-01

    A caisson foundation is applied to the north anchorage of Taizhou Yangtze River Highway Bridge of which the initial caisson sinking requires dewatering. Since the caisson foundation is quite close to nearby buildings, a system control model is established with source (sink) distribution and intensity being the object function, minimum requirements of settlement and deformation of surroundings caused by dewatering and dynamic water levels during different working procedures being constraints, and the design parameter of pumping wells being the variable, so as to lower the jeopardizing of surrounding buildings, which provides a new method for active control over settlement during dewatering. Such a method of dewatering based on system control model should be of significance for similar projects involving dewatering.

  6. Observations of ebb flows on tidal flats: Evidence of dewatering?

    Science.gov (United States)

    Rinehimer, J. P.; Thomson, J. M.; Chickadel, C.

    2010-12-01

    Incised channels are a common morphological feature of tidal flats. When the flats are inundated, flows are generally forced by the tidally varying sea surface height. During low tide, however, these channels continue to drain throughout flat exposure even without an upstream source of water. While the role of porewater is generally overlooked due to the low permeability of marine muds, it remains the only potential source of flows through the channels during low tide. In situ and remotely sensed observations (Figure 1) at an incised channel on a tidal flat in Willapa Bay from Spring 2010 indicate that dewatering of the flats may be driving these low tide flows. High resolution Aquadopp ADCP velocity profiles are combined with observations from tower-based infrared (IR) video to produce a complete time series of surface velocity measurements throughout low tide. The IR video observations provide a measurement of surface currents even when the channel depth is below the blanking distance of the ADCP (10 cm). As the depth within the channel drops from 50 cm to 10 cm surface velocities increase from 10 cm/s to 60 cm/s even as the tide level drops below the channel flanks and the flats are dry. As the drainage continues, the temperature of the flow rises throughout low tide, mirroring temperatures within the sediment bed on the tidal flat. Drainage salinity falls despite the lack of any freshwater input to the flat indicating that less saline porewater may be the source. The likely source of the drainage water is from the channel flanks where time-lapse video shows slumping and compaction of channel sediments. Velocity profiles, in situ temperatures, and IR observations also are consistent with the presence of fluid muds and a hyperpycnal, density driven outflow at the channel mouth highlighting a possible pathway for sediment delivery from the flats to the main distributary channels of the bay. Figure 1: Time series of tidal flat channel velocities and temperatures

  7. Monitoring and troubleshooting of non-filamentous settling and dewatering problems in an industrial activated sludge treatment plant

    DEFF Research Database (Denmark)

    Kjellerup, B. V.; Keiding, Kristian; Nielsen, Per Halkjær

    2001-01-01

    A large industrial activated sludge wastewater treatment plant had temporary problems with settling and dewatering of the sludge. Microscopical investigations revealed that the poor settling properties were not due to presence of filamentous bacteria, but poor floc properties. In order...... at this industrial plant. The described strategy can be useful in general to find and solve many solid/liquid separation problems in activated sludge wastewater treatment plants....... had started after summer closedown. Possible reasons for the changes in floc properties in the process tanks were found by a) analysing change in wastewater composition by evaluating the different production lines in the industrial plant, b) evaluating the operation of the plant, and c) performing...

  8. A EDUCAÇÃO A DISTÂNCIA COMO INDÚSTRIA CULTURAL: REFLEXÕES SOBRE A DOCÊNCIA NA EaD

    OpenAIRE

    Ripa, Roselaine

    2016-01-01

    A partir da contradição imanente que permeia o termo “educação a distância”, esse artigo pretende se aproximar das discussões sobre como os ditames da indústria cultural atingem o trabalho docente na EaD, procurando desvelar a incorporação instrumental e reificada das TICs no processo de ensino e aprendizagem à distância.

  9. Comparative GC-EAD responses of a specialist (Microplitis croceipes) and a generalist (Cotesia marginiventris) parasitoid to cotton volatiles induced by two caterpillar species.

    Science.gov (United States)

    Ngumbi, Esther; Chen, Li; Fadamiro, Henry Yemisi

    2009-09-01

    Plants emit volatile blends that may be quantitatively and/or qualitatively different in response to attack by different herbivores. These differences may convey herbivore-specific information to parasitoids, and are predicted to play a role in mediating host specificity in specialist parasitoids. Here, we tested the above prediction by using as models two parasitoids (Hymenoptera: Braconidae) of cotton caterpillars with different degree of host specificity: Microplitis croceipes, a specialist parasitoid of Heliothis spp., and Cotesia marginiventris, a generalist parasitoid of caterpillars of several genera including Heliothis spp. and Spodoptera spp. We compared GC-EAD (coupled gas chromatography electroantennogram detection) responses of both parasitoid species to headspace volatiles of cotton plants damaged by H. virescens (a host species for both parasitoids) vs. S. exigua (a host species for C. marginiventris). Based on a recent study in which we reported differences in the EAG responses of both parasitoids to different types of host related volatiles, we hypothesized that M. croceipes (specialist) would show relatively greater GC-EAD responses to the herbivore-induced plant volatile (HIPV) components of cotton headspace, whereas C. marginiventris (generalist) would show greater response to the green leaf volatile (GLV) components. Thirty volatile components were emitted by cotton plants in response to feeding by either of the two caterpillars, however, 18 components were significantly elevated in the headspace of H. virescens damaged plants. Sixteen consistently elicited GC-EAD responses in both parasitoids. As predicted, C. marginiventris showed significantly greater GC-EAD responses than M. croceipes to most GLV components, whereas several HIPV components elicited comparatively greater responses in M. croceipes. These results suggest that differences in the ratios of identical volatile compounds between similar volatile blends may be used by specialist

  10. 46 CFR 28.815 - Bilge pumps, bilge piping, and dewatering systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Bilge pumps, bilge piping, and dewatering systems. 28... REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.815 Bilge pumps, bilge... fixed, self priming, powered, bilge pump, having a minimum capacity rating of 50 gallons per...

  11. Geotextile filtration performance for lagoon sludges and liquid animal manures dewatering

    Science.gov (United States)

    Maintenance and control of liquid levels in anaerobic lagoons and storage ponds require liquid-solid separation as a pretreatment and periodic removal of accumulated sludges. Until local options become available, sludges can be contained, dewatered, and stored using geotextile filtration. We used a ...

  12. Feasibility of electro-osmotic belt filter dewatering technology at pilot scale

    CSIR Research Space (South Africa)

    Snyman, HG

    2000-01-01

    Full Text Available -effective dewatering technologies, electro-osmotic belt filtering was developed by Smollen and Kafaar in 1995. The mechanical equipment resembles a belt filter press but the belts are stainless steel, woven belts, which act as the electrodes. In this study...

  13. Synthesis, characterization, and secondary sludge dewatering performance of a novel combined silicon–aluminum–iron–starch flocculant

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Qintie, E-mail: qintlin@163.com; Peng, Huanlong; Zhong, Songxiong; Xiang, Jiangxin

    2015-03-21

    Highlights: • Silicon, aluminum, and iron were grafted onto starch chains to synthesize CSiAFS. • The sludge dewatering performance of CSiAFS was superior to PAC, PAM, and FeCl{sub 3}. • CSiAFS exhibited a good dewatering efficiency over a wide range of pH (3.0–11.0). • CSiAFS had a discontinuous surface with channels which helped to sludge dewatering. - Abstract: Flocculation is one of the most widely used cost-effective pretreatment method for sludge dewatering, and a novel environmentally friendly and efficient flocculant is highly desired in the sludge dewatering field. In this study, a novel combined silicon–aluminum–ferric–starch was synthesized by grafting silicon, aluminum, and iron onto a starch backbone. The synthesized starch flocculant was characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy, X-ray powder diffraction, and thermogravimetric analysis. The dewatering performance of secondary sludge was evaluated according to the capillary suction time, settling volume percentage, and specific resistance to filtration. The results indicated that the copolymer exhibited: (1) a good dewatering efficiency over a wide pH range of 3.0–11.0, (2) superior sludge dewatering performance compared to those of polyaluminum chloride (PACl), polyacrylamide (PAM), ferric chloride, and (3) a discontinuous surface with many channels or voids that helps to mobilize the impermeable thin layer of secondary sludge during filter pressing. Such a novel copolymer is a promising green flocculant for secondary sludge dewatering applications.

  14. Hydrothermal and alkaline hydrothermal pretreatments plus anaerobic digestion of sewage sludge for dewatering and biogas production: Bench-scale research and pilot-scale verification.

    Science.gov (United States)

    Li, Chunxing; Wang, Xingdong; Zhang, Guangyi; Yu, Guangwei; Lin, Jingjiang; Wang, Yin

    2017-06-15

    To test the feasibility and practicability of the process combing hydrothermal pretreatment for dewatering with biogas production for full utilization of sewage sludge, hydrothermal/alkaline hydrothermal pretreatments and in turn anaerobic digestion of the filtrates obtained after dewatering the pretreated sludge were performed at bench- and pilot-scales. The hydrothermal temperature fell within the range of 140 °C-220 °C and the pretreatment time varied from 30 min to 120 min. For the alkaline hydrothermal pretreatment the pH value of the sludge was adjusted to 9.0-11.0 by adding Ca(OH)2. The results showed that the dewaterability of the sewage sludge was improved with increasing pretreatment temperature but the impact of the pretreatment time was not significant. The addition of Ca(OH)2 gave better performance on the subsequent mechanical dewatering of the pretreated sludge compared to pure hydrothermal pretreatment, and the higher the pH value was, the better the dewaterability of the pretreated sludge was. The conditions of 180 °C/30 min and 160 °C/60 min/pH = 10.0 (for hydrothermal and alkaline hydrothermal pretreatments, respectively) resulted in relatively good results in the theoretical energy balance, which were verified in the pilot-scale tests. Based on the data from the pilot tests, the alkaline hydrothermal process realized self-sufficiency in energy at the cost of a proper amount of CaO. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. 调理脱水污泥的热解特性及动力学分析%Pyrolysis characteristics and kinetics analysis of conditioned dewatered sewage sludge

    Institute of Scientific and Technical Information of China (English)

    徐新宇; 杨家宽; 宋健; 时亚飞; 虞文波; 郦超; 何姝; 吴旭; 梁莎

    2016-01-01

    利用TGA(Thermogravimetric analysis)热分析技术对污水处理厂原始污泥及调理脱水污泥进行了实验研究,获得了不同升温速率下污泥的TG (Thermogravimetric)和DTG失重曲线.实验发现,不同调理脱水污泥热解特性复杂,且热解动力学在不同转化率下对应的动力学反应也不同.并利用M-KAS(Kissinger-AkahiraSunose)模型和Discrete DAEM(Discrete distribute activation energy model)模型对不同调理污泥进行了动力学参数研究.结果表明,污泥的非等温热解过程包含3个失重阶段;升温速率影响污泥热解特征温度,随着升温速率的提高,失重曲线向高温区滑移.利用上述模型计算的动力学参数变化趋势表明所采用的Fenton及赤泥复合调理对污泥热解特性有很大影响,Fenton调理有助于污泥EPS(Extracellular polymeric substances)破坏,影响热解反应中的形核过程,进而影响热解动力学变化趋势;赤泥调理后,赤泥更容易与破坏的污泥细小颗粒结合,增加了污泥热解反应数量,影响整个污泥热解过程.从计算结果可以看出污泥热解由多步反应组成,整个热解过程动力学参数不断变化.%Raw and conditioned dewatered sewage sludges of sewage treatment plant were analysed by the TGA thermal analysis technique,and TG and DTG curves were obtained at different heating rates.Experimental results showed that the pyrolysis characteristics of different conditioned dewatered sludge were complex and pyrolysis kinetics with different conversion ratios corresponded to different kinetic reations.M-KAS model and Discrete DAEM model were also applied to analyze the kinetic parameters of different conditioned dewatered sewage sludge.The results showed that the nonisothermal decomposition process of dewatered sewage sludge contained three weight loss stages and the heating rate influenced the characteristic temperature zones of pyrolysis.With increasing heating rate,the weight loss curve slipped

  16. Feasibility of vermicomposting dewatered sludge from paper mills using Perionyx excavatus

    Directory of Open Access Journals (Sweden)

    Puspanjali Sonowal

    2013-06-01

    Full Text Available India has a large network of pulp and paper mills of varying capacity. On an industrial scale the sludge from paper and pulp mills is disposed of either as landfill or incinerated. Both methods result in the loss of a valuable resource and have obvious environmental and economic disadvantages. The solid waste from pulp and paper mills is a source of organic matter and its proper disposal and management is the responsibility of the industry. As composting/vermicomposting could be used to transform this waste trials were carried out to determine the feasibility of converting dewatered sludge (DS into a value added end product using an earthworm, Perionyx excavatus. The vermicomposting of the waste resulted in an increase in its electrical conductivity (EC, ash content, total nitrogen (TN, total phosphorous (TP and available phosphorous (AP, respectively, and a decrease in total organic carbon (TOC, biochemical oxygen demand (BOD, chemical oxygen demand (COD, oxygen uptake rate (OUR and evolution of carbon dioxide (CO2. Overall, the best treatment was T5 in which there was a 76.1% increase in TP, 58.7% in TN, 74.5% decrease in TOC , and a reduction of 6.7 fold in the production of CO2 and 10.7 fold in BOD, respectively. Our trials demonstrate that vermicomposting using an epigeic earthworm, Perionyx excavatus, is an alternate and environmentally safe way of recycling paper mill sludge if it is mixed with an appropriate amount of cow dung and food processing waste. Overall T5 was the best combination of paper mill sludge and waste for vermicomposting followed by T3, T2, T4 and T1, respectively.

  17. Coontail fluorite rhythmites of southern Illinois: evidence for episodic basin dewatering

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, C.A.; Kelly, W.C.; Wilkinson, B.H.

    1985-01-01

    Stratiform coontail ore of the Cave-in-Rock fluorite district, southern Illinois, display conspicuous, rhythmic banded textures similar to those reported in many MVT deposits throughout the world (e.g., east Tennessee, USA; Silesian-Cracow Region, Poland; and northern Baffin Island, Canada). Banding is expressed by the rhythmic alteration of two types of layers: detrital layers of fluorite mottled with particulate gangue dolomite and quartz, and layers of clear, crystalline fluorspar. Both are now composed principally of fluorite but differ in color, fabric and outline. In the past, this rhythmic banding has generally been attributed to fine-scale replacement of a primary host rock stratification or to cyclic replacement of host carbonates by a fluid of oscillating chemistry. Detailed megascopic and microscopic studies of these ores and their carbonate host real that ore bands were not derived by fine-scale in situ limestone replacement. Detrital bands contain hydraulically transported, sorted and graded, allochthonous debris derived by dissolution and disaggregation of host limestone and overlying shale. The banded fabric thus represents a cyclic interplay of chemical and hydraulic processes active during hydrothermal ore mineralization. Coontail ore bodies evidently formed in a hydrothermal spelean system, whose laterally sinuous trace reflects localization of hydrothermal activity where feeder faults intersected relatively impermeable roof-rock shales. The banded nature of these ores testifies to the ability of Mississippi Valley-type hydrothermal solutions to both create and fill their own open spaces. Moreover, the rhythmic nature of coontail ores suggests a prolonged and pulsating mineralization best explained by episodic dewatering of the Illinois Basin.

  18. Lignite Drying and Dewatering Technologies%褐煤干燥脱水技术

    Institute of Scientific and Technical Information of China (English)

    孟顺; 孙绍增; 赵广播

    2013-01-01

    With a high water content, lignite has a low efficiency for direct combustion power generation. The lignite drying and dewatering technology can effectively lower the water content of lignite- and enhance its competitive power. On this basis, the authors studied and analyzed the principles of the following technologies, namely, flue gas drying technology , steam drying technology (tube type drying and fluidized bed steam drying) , hydrothermal dewatering technology, mechanical thermal dehydration (MTE) technology and upgraded brown coal (UBC) technology. Moreover,they also contrasted and analyzed the pressure, temperature, removing state, dewatering effectiveness, pore structure and re-absorption characteristics of various drying and dewatering technologies. The mechanical thermal dehydration technology can change the pore structure of brown coal and prevent from re-absorption, thus achieving a relatively high dewatering efficiency with a low energy consumption rate. It is of major significance for China to develop novel drying and dewatering technologies with due consideration of the brown coal distribution features of China to lower the water content of coal from its source, realize an economic transportation of coal and enhance the power generation efficiency of power plants.%褐煤含水量高,直接燃烧发电效率低.褐煤干燥脱水技术能有效降低褐煤含水量,提高其竞争力.研究介绍了烟气干燥技术、蒸汽干燥(管式干燥,流化床蒸汽干燥)、水热脱水技术、机械热力脱水技术(MTE)和热油干燥技术(UBC)5种褐煤干燥脱水技术的原理;对比分析了不同干燥脱水技术的压力、温度、脱除状态、脱水效率、孔隙结构和重吸收特性;机械热力脱水技术(MTE)可以改变褐煤孔隙结构、防止重吸收、脱水效率较高和能耗低.结合我国褐煤分布特点,开发新型干燥脱水技术,在源头降低煤的水分含量,实现煤的经济运输,提高电厂的发电效率.

  19. Super-energy-saving dewatering method for high-specific-surface-area fuels by using dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Kanda, H. [Central Research Institute for Electric Power Industry, Kanagawa (Japan)

    2008-07-01

    There is a growing need for the economical dewatering of high-specific-surface-area fuels containing large amounts of water, such as coal and sewage sludge. The principle underlying conventional dewatering methods is evaporation of the water content by heating the fuels to a high temperature, but this approach consumes a considerable amount of energy. The Central Research Institute of the Electric Power Industry (CRIEPI) has developed a method for the extraction of this water through the use of dimethyl ether (DME), which liquefies at ordinary temperatures under the influence of a slight pressure. In this method, the water content in the fuel is extracted into the liquefied DME for separation from the fuel. After dewatering, the DME is depressurised, and subsequently vaporised, thereby leaving the separated water. Dewatering with an input energy of only 1109 kJ/kg water under ordinary conditions has been demonstrated theoretically.

  20. Avaliação da experiência em EaD em um contexto de formação de formadores/Evaluation of Distance Education experience in a context of qualification of trainers

    Directory of Open Access Journals (Sweden)

    Heloisa Collins

    2009-06-01

    Full Text Available O objetivo deste artigo é analisar e discutir o que dizem sobre sua experiência em EAD alguns professores que vivenciaram um longo e exigente processo de formação continuada a distância. Para tanto, é apresentado um breve relato da experiência em EAD vivida pelos participantes do curso de formação continuada a distância Práticas de Leitura e Escrita na Contemporaneidade e oferecida uma interpretação de um conjunto de depoimentos de professores-alunos para tentar mostrar que processos de EAD podem, democraticamente, beneficiar diferentes tipos de alunos, gerar ótimos níveis de motivação para a aprendizagem e para o trabalho e oportunizar ricas relações humanas com alto grau de proximidade. A análise dos comentários dos alunos sobre sua aprendizagem e experiência digital faz uso de um aparato teórico proposto pela Linguística Sistêmico-Funcional. A interpretação dos depoimentos é então apoiada em uma análise da avaliatividade expressa na linguagem. Uma vez que realizamos avaliações para contar aos nossos ouvintes ou leitores como nos sentimos em relação a coisas ou pessoas, ou seja, que posições assumimos em relação a elas (Martin, 2003, é possível e importante tentar mapear os tipos de avaliações que os professores-alunos utilizam para falar de sua experiência, dos participantes e do curso. The aim of this paper is to analyze and discuss what some teachers say about a distance learning experience during a long and demanding distance teacher development process. To do this, we first present a report on the experience in the teacher development course Práticas de Leitura e Escrita na Contemporaneidade (Reading and Writing Practices in Contemporaneity; then, we offer an interpretation about a set of evaluative reports the participants made. Our aim is to argue that distance courses can be democratically beneficial to different types of students, motivating for work and study and an opportunity for the

  1. Sludge dewatering on filters aiming the utilization as fuel; Desaguamento de lodos em filtro visando aproveitamento como combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Paschoalim, Luis Gustavo; Neves, Jose Mangolini

    1992-12-31

    This work presents modern methodologies for sludge dewatering and alternatives for environmental disposal of the so obtained cakes. Among the possible alternatives, special emphasis is given to the characterization and study of the variables which determine the behaviour of dewatering operation of sludges form pulp and paper industries. Results are presents for bench scale tests and pilot plant tests 28 refs., 9 figs., 7 tabs.

  2. Synthesis, characterization, and secondary sludge dewatering performance of a novel combined silicon-aluminum-iron-starch flocculant.

    Science.gov (United States)

    Lin, Qintie; Peng, Huanlong; Zhong, Songxiong; Xiang, Jiangxin

    2015-03-21

    Flocculation is one of the most widely used cost-effective pretreatment method for sludge dewatering, and a novel environmentally friendly and efficient flocculant is highly desired in the sludge dewatering field. In this study, a novel combined silicon-aluminum-ferric-starch was synthesized by grafting silicon, aluminum, and iron onto a starch backbone. The synthesized starch flocculant was characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy, X-ray powder diffraction, and thermogravimetric analysis. The dewatering performance of secondary sludge was evaluated according to the capillary suction time, settling volume percentage, and specific resistance to filtration. The results indicated that the copolymer exhibited: (1) a good dewatering efficiency over a wide pH range of 3.0-11.0, (2) superior sludge dewatering performance compared to those of polyaluminum chloride (PACl), polyacrylamide (PAM), ferric chloride, and (3) a discontinuous surface with many channels or voids that helps to mobilize the impermeable thin layer of secondary sludge during filter pressing. Such a novel copolymer is a promising green flocculant for secondary sludge dewatering applications.

  3. Application of organic polymeric fiocculants in centrifugal dewatering of oil refinery sludge

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In order to evaluate the applicability of the organic polymeric floeculants(OPF) in the treatment of oil refinery sludge, experimentswere conducted to show that OPF have better performance of flocculation than inorganic flocculants. Both the anionic and cationic OPF havesatisfactory flocculation efficiency in oil sludge treatment, but the latter are more cost-efficient. Among the over 20 types of flocculants tested,2OPF(CPAM-2 and HPAM-2) were selected as the treatment agents, based on their good treatment performances, oil-resistance and economicfeasibility. It was demonstrated in the industrial-scale centrifugal dewatering experiments that the application of either CPAM-2 or HPAM-2could achieve high treatment efficiency of the oil sludge dewatering and reduce the COD of centrifugal liquid to less than 1000 mg/L.

  4. Harmless treatment of used foundry sands and dewatered municipal sludge by microwave

    Directory of Open Access Journals (Sweden)

    H. F. Wang

    2015-07-01

    Full Text Available A new method to treat four solid wastes of sodium silicate used sands, dewatered municipal sludge, clay sands sludge and waste polyethylene, was discussed. About wt/ 50 % sodium silicate used sands and wt/ 50 % dewatered sludge were mixed, and then cured by microwave with a certain thickness film of clay sands sludge and waste plastic of polyethylene in the surface. The results showed that the compression strength of granulation sample with the size of Ф 50 × 50 mm was over 0,45 MPa. The waste plastic was the key factor for the durability, and curing temperature must be over melting temperature, so the thicker film could be coated in the surface of used sands and sludge.

  5. An experimental investigation of microalgal dewatering efficiency of belt filter system

    Directory of Open Access Journals (Sweden)

    Anjali Sandip

    2015-11-01

    Full Text Available The objective of this study was to investigate the microalgal dewatering efficiency of a belt filter system for feed concentrations below 10 g dry wt./L. A prototype belt filtration system designed for 50 g dry wt./L microalgal feed concentration was used for this investigation. The highest concentration of microalgal suspension available for testing on the prototype belt filtration system was 6 g dry wt./L obtained from biomass settling tanks at the Lawrence, Kansas domestic wastewater treatment plant. For preparation of feed suspension with concentrations below 10 g dry wt./L, microalgal cultivation was followed by flocculation. A mixed laboratory culture of freshwater species dominated by three eukaryotic green microalgae (Chlorella vulgaris, Scenedesmus sp., and Kirchneriella sp. was cultivated in wastewater effluent. This was followed by flocculation which resulted in a microalgal feed suspension concentration of 4 g dry wt./L. Belt dewatering tests were conducted on microalgal suspensions with feed concentrations of 4 g dry wt./L and 6 g dry wt./L. The maximum microalgal recovery with the belt dewatering system was 46% from the 4 g dry wt./L, and 84% from the 6 g dry wt./L suspensions respectively. The results of this study indicate that microalgal suspension concentrations as low as 6 g dry wt./L can be recovered with a belt filter system improving the overall dewatering efficiency of the system.

  6. Investigation of Parameters Affecting Gypsum Dewatering Properties in a Wet Flue Gas Desulphurization Pilot Plant

    OpenAIRE

    Hansen, Brian Brun; Kiil, Søren

    2012-01-01

    Wet flue gas desulphurization (FGD) plants with forced oxidation, installed at coal and oil fired power plants for removal of SO2(g), must produce gypsum of high quality. However, quality issues such as an excessive moisture content, due to poor gypsum dewatering properties, may occur from time to time. In this work, the particle size distribution, morphology, and filtration rate of wet FGD gypsum formed in a pilot-scale experimental setup, operated in forced oxidation mode, have been studied...

  7. Dewatering and low-temperature pyrolysis of oily sludge in the presence of various agricultural biomasses.

    Science.gov (United States)

    Zhao, Song; Zhou, Xiehong; Wang, Chuanyi; Jia, Hanzhong

    2017-08-24

    Pyrolysis is potentially an effective treatment of waste oil residues for recovery of petroleum hydrocarbons, and the addition of biomass is expected to improve its dewatering and pyrolysis behavior. In this study, the dewatering and low-temperature co-pyrolysis of oil-containing sludge in the presence of various agricultural biomasses, such as rice husk, walnut shell, sawdust, and apricot shell, were explored. As a result, the water content gradually decreases with the increase of biomass addition within 0-1.0 wt % in original oily sludge. Comparatively, the dewatering efficiency of sludge in the presence of four types of biomasses follows the order of apricot shell > walnut shell > rice husk > sawdust. On the other hand, rice husk and sawdust are relatively more efficient in the recovery of petroleum hydrocarbons compared with walnut shell and apricot shell. The recovery efficiency generally increased with the increase in the biomass content in the range of 0-0.2 wt %, then exhibited a gradually decreasing trend with the increase in the biomass content from 0.2 to 1.0 wt %. The results suggest that optimum amount of biomass plays an important role in the recovery efficiency. In addition, the addition of biomass (such as rice husk) also promotes the formation of CxHy and CO, increasing the calorific value of pyrolysis residue, and controlled the pollution components of the exhaust gas discharged from residue incineration. The present work implies that biomass as addictive holds great potential in the industrial dewatering and pyrolysis of oil-containing sludge.

  8. Simple systems for treating pumped, turbid water with flocculants and a geotextile dewatering bag.

    Science.gov (United States)

    Kang, Jihoon; McLaughlin, Richard A

    2016-11-01

    Pumping sediment-laden water from excavations is often necessary on construction sites. This water is often treated by pumping it through geotextile dewatering bags. The bags are not designed to filter the fine sediments that create high turbidity, but dosing with a flocculant prior to the bag could result in greater turbidity control. This study compared two systems for introducing flocculant: passive dosing of commercial solid biopolymer (chitosan) and injection of dissolved polyacrylamide (PAM) in a length of corrugated pipe connected to the bag. The biopolymer system consisted of sequential porous socks containing a "charging agent" followed by chitosan in the corrugated pipe with two levels of dosing. The dissolved PAM was injected into turbid water at a flow-weighted concentration at 1 mg L(-1). For each treatment, sediment-laden turbid water in the range of 2000 to 3500 nephelometric turbidity units (NTU) was pumped into the upstream of corrugated pipe and samples were taken from pipe entrance, pipe exit, and dewatering bag exit. Without flocculant treatment, the dewatering bag reduced turbidity by 70% but the addition of flocculant increased the turbidity reduction up to 97% relative to influent. At the pipe exit, the low-dose biopolymer was less effective in reducing turbidity (37%) but it was equally effective as the high-dose biopolymer or PAM injection after the bag. Our results suggest that a relatively simple treatment with flocculants, either passively or actively, can be very effective in reducing turbidity for pumped water on construction sites.

  9. Ecotoxicological assessment of dewatered drinking water treatment residue for environmental recycling.

    Science.gov (United States)

    Yuan, Nannan; Wang, Changhui; Wendling, Laura A; Pei, Yuansheng

    2016-11-18

    The beneficial recycle of drinking water treatment residue (DWTR) in environmental remediation has been demonstrated in many reports. However, the lack of information concerning the potential toxicity of dewatered DWTR hinders its widespread use. The present study examined the ecotoxicity of dewatered aluminum (Al) and iron (Fe) DWTR leachates to a green alga, Chlorella vulgaris. Data from the variations of cell density and chlorophyll a content suggested that algal growth in DWTR leachates was inhibited. The algal cellular oxidation stress was initially induced but completely eliminated within 72 h by antioxidant enzymes. The expression of three photosynthesis-related algae genes (psaB, psbC, and rbcL) also temporarily decreased (within 72 h). Moreover, the algal cells showed intact cytomembranes after exposure to DWTR leachates. Further investigation confirmed that inhibition of algal growth was due to DWTR-induced phosphorus (P) deficiency in growth medium, rather than potentially toxic contaminants (e.g. copper and Al) contained in DWTR. Interestingly, the leachates could potentially promote algal growth via increasing the supply of new components (e.g. calcium, kalium, magnesium, and ammonia nitrogen) from DWTR. In summary, based on the algae toxicity test, the dewatered Fe/Al DWTR was nontoxic and its environment recycling does not represent an ecotoxicological risk to algae.

  10. Bioelectricity generation and dewatered sludge degradation in microbial capacitive desalination cell.

    Science.gov (United States)

    Meng, Fanyu; Zhao, Qingliang; Na, Xiaolin; Zheng, Zhen; Jiang, Junqiu; Wei, Liangliang; Zhang, Jun

    2016-05-18

    Microbial desalination cell (MDC) is a new approach for the synergy in bioelectricity generation, desalination and organic waste treatment without additional power input. However, current MDC systems cause salt accumulation in anodic wastewater and sludge. A microbial capacitive desalination cell (MCDC) with dewatered sludge as anodic substrate was developed to address the salt migration problem and improve the sludge recycling value by special designed-membrane assemblies, which consisted of cation exchange membranes (CEMs), layers of activated carbon cloth (ACC), and nickel foam. Experimental results indicated that the maximum power output of 2.06 W/m(3) with open circuit voltage (OCV) of 0.942 V was produced in 42 days. When initial NaCl concentration was 2 g/L, the desalinization rate was about 15.5 mg/(L·h) in the first 24 h, indicating that the MCDC reactor was suitable to desalinize the low concentration salt solution rapidly. The conductivity of the anodic substrate decreased during the 42-day operation; the CEM/ACC/Ni assemblies could effectively restrict the salt accumulation in MCDC anode and promote dewatered sludge effective use by optimizing the dewatered sludge properties, such as organic matter, C/N, pH value, and electric conductivity (EC).

  11. Scale-down of continuous filtration for rapid bioprocess design: Recovery and dewatering of protein precipitate suspensions.

    Science.gov (United States)

    Reynolds, T; Boychyn, M; Sanderson, T; Bulmer, M; More, J; Hoare, M

    2003-08-20

    The early specification of bioprocesses often has to be achieved with small (tens of millilitres) quantities of process material. If extensive process discovery is to be avoided at pilot or industrial scale, it is necessary that scale-down methods be created that not only examine the conditions of process stages but also allows production of realistic output streams (i.e., streams truly representative of the large scale). These output streams can then be used in the development of subsequent purification operations. The traditional approach to predicting filtration operations is via a bench-scale pressure filter using constant pressure tests to examine the effect of pressure on the filtrate flux rate and filter cake dewatering. Interpretation of the results into cake resistance at unit applied pressure (alpha) and compressibility (n) is used to predict the pressure profile required to maintain the filtrate flux rate at a constant predetermined value. This article reports on the operation of a continuous mode laboratory filter in such a way as to prepare filter cakes and filtrate similar to what may be achieved at the industrial scale. Analysis of the filtration rate profile indicated the filter cake to have changing properties (compressibility) with time. Using the insight gained from the new scale-down methodology gave predictions of the flux profile in a pilot-scale candle filter superior to those obtained from the traditional batch filter used for laboratory development.

  12. Análise da utilização das tecnologias da informação e comunicação na educação a distância (EaD.

    Directory of Open Access Journals (Sweden)

    Carla Simone Pires

    2017-02-01

    Full Text Available A EaD se caracteriza por docentes e discentes fisicamente separados, conectados por TICs. No Brasil a EaD não é recente, entretanto, tem aumentado nos últimos anos devido a políticas públicas e à evolução das TICs, entretanto, a sua aplicação normalmente tem foco na economia de recursos. Apesar das dificuldades encontradas, é tendência mundial e converge para o uso de tecnologias. Neste sentido, TICs podem causar inclusão/exclusão social, dependendo de como sua utilização é planejadas. O mesmo ocorre com processos avaliativos, que mostram fragilidades. Os resultados permitem concluir que a transição para EaD não apresenta mudanças de práticas pedagógicas. Apesar disto, tem importante papel social, uma vez que vem suprir demandas reprimidas no que tange o acesso à educação superior, além de incentivar o desenvolvimento de municípios com Baixos Índice de Desenvolvimento Humano (IDH e Índice de Desenvolvimento da Educação Básica (IDEB. Ainda, mostra a necessidade de redimensionar as práticas de ensino (reinventando usos para TICs na transição entre ensino presencial e EaD, possibilitando que a EaD assuma sua função social na educação brasileira. Neste sentido,  Este trabalho teve como objetivo fazer um estudo analítico do contexto da Educação a Distância (EaD no Brasil, as práticas pedagógicas usadas e o papel das Tecnologias de Informação (TICs neste processo.

  13. Effects of dilution ratio and Fe° dosing on biohydrogen production from dewatered sludge by hydrothermal pretreatment.

    Science.gov (United States)

    Yu, Li; Jiang, Wentian; Yu, Yang; Sun, Chenglin

    2014-01-01

    Biohydrogen fermentation of dewatered sludge (DS) with sewage at ratios from 4:1 to 1:20 was investigated. Hydrothermal pretreatment of the sludge solution was performed to accelerate the organic release from the solid phase. The maximum hydrogen yield of 26.3 ± 0.5 mL H₂/g volatile solid (VS) was obtained at a 1:10 ratio. Although addition of zero valent iron (ZVI) to anaerobic system was not new, the study of dosing it to enhance the biohydrogen yield might be the first attempt. While Fe° plate slightly affected the hydrogen yield, Fe° powder improved the amount of hydrogen by 16% and shortened the lag time by 36%. The state of bacteria in the reactor added with ZVI powder was changed and the key enzyme activity was improved as well. Correspondingly, the mechanism of ZVI in accelerating the biofermentation process was also proposed. Our research provides a solution for the centralized treatment of DS in a city.

  14. Effects of cationic polyacrylamide characteristics on sewage sludge dewatering and moisture evaporation.

    Directory of Open Access Journals (Sweden)

    Jun Zhou

    Full Text Available The effects of the molecular weight (MW and charge density (CD of cationic polyacrylamide (CPAM on sludge dewatering and moisture evaporation were investigated in this study. Results indicated that in sludge conditioning, the optimum dosages were 10, 6, 6, 4, and 4 mg g(-1 CPAM with 5 million MW and 20% CD, 5 million MW and 40% CD, 3 million MW and 40% CD, 8 million MW and 40% CD, and 5 million MW and 60% CD, respectively. The optimum dosage of CPAM was negatively correlated with its CD or MW if the CD or MW of CPAM was above 20% or 5 million. In the centrifugal dewatering of sludge, the moisture content in the conditioned sludge gradually decreased with the extension of centrifugation time, and the economical centrifugal force was 400×g. The moisture evaporation rates of the conditioned sludge were closely related to sludge dewaterability, which was in turn significantly correlated either positively with the solid content of sludge particles that were >2 mm in size or negatively with that of particles measuring 1 mm to 2 mm in diameter. During treatment, sludge moisture content was reduced from 80% to 20% by evaporation, and the moisture evaporation rates were 1.35, 1.49, 1.62, and 2.24 times faster in the sludge conditioned using 4 mg g(-1 CPAM with 5 million MW and 60% CD than in the sludge conditioned using 4 mg g(-1 CPAM with 8 million MW and 40% CD, 6 mg g(-1 CPAM with 5 million MW and 40% CD, 6 mg g(-1 CPAM with 3 million MW and 40% CD, and 10 mg g(-1 CPAM with 5 million MW and 20% CD, respectively. Hence, the CPAM with 5 million MW and 60% CD was ideal for sludge dewatering.

  15. Textural evidence for jamming and dewatering of a sub-surface, fluid-saturated granular flow

    Science.gov (United States)

    Sherry, T. J.; Rowe, C. D.; Kirkpatrick, J. D.; Brodsky, E. E.

    2011-12-01

    Sand injectites are spectacular examples of large-scale granular flows involving migration of hundreds of cubic meters of sand slurry over hundreds of meters to kilometers in the sub-surface. By studying the macro- and microstructural textures of a kilometer-scale sand injectite, we interpret the fluid flow regimes during emplacement and define the timing of formation of specific textures in the injected material. Fluidized sand sourced from the Santa Margarita Fm., was injected upward into the Santa Cruz Mudstone, Santa Cruz County, California. The sand injectite exposed at Yellow Bank Beach records emplacement of both hydrocarbon and aqueous sand slurries. Elongate, angular mudstone clasts were ripped from the wall rock during sand migration, providing evidence for high velocity, turbid flow. However, clast long axis orientations are consistently sub-horizontal suggesting the slurry transitioned to a laminar flow as the flow velocity decreased in the sill-like intrusion. Millimeter to centimeter scale laminations are ubiquitous throughout the sand body and are locally parallel to the mudstone clast long axes. The laminations are distinct in exposure because alternating layers are preferentially cemented with limonite sourced from later groundwater infiltration. Quantitative microstructural analyses show that the laminations are defined by subtle oscillations in grain alignment between limonite and non-limonite stained layers. Grain packing, size and shape distributions do not vary. The presence of limonite in alternating layers results from differential infiltration of groundwater, indicating permeability changes between the layers despite minimal grain scale differences. Convolute dewatering structures deform the laminations. Dolomite-cemented sand, a signature of hydrocarbon saturation, forms irregular bodies that cross-cut the laminations and dewatering structures. Laminations are not formed in the dolomite-cemented sand. The relative viscosity difference

  16. STELLA software as a tool for modelling phosphorus removal in a constructed wetland employing dewatered alum sludge as main substrate.

    Science.gov (United States)

    Kumar, J L G; Wang, Z Y; Zhao, Y Q; Babatunde, A O; Zhao, X H; Jørgensen, S E

    2011-01-01

    A dynamic simulation model was developed for the removal of soluble reactive phosphorus (SRP) from the vertical flow constructed wetlands (VFCW) using a dynamic software program called STELLA (structural thinking, experiential learning laboratory with animation) 9.1.3 to aid in simulating the environmental nature and succession of relationship between interdependent components and processes in the VFCW system. In particular, the VFCW employed dewatered alum sludge as its main substrate to enhance phosphorus (P) immobilization. Although computer modelling of P in treatment wetland has been well studied especially in recent years, there is still a need to develop simple and realistic models that can be used for investigating the dynamics of SRP in VFCWs. The state variables included in the model are dissolved phosphorus (DISP), plant phosphorus (PLAP), detritus phosphorus (DETP), plant biomass (PLBI) and adsorbed phosphorus (ADSP). The major P transformation processes considered in this study were adsorption, plant and microbial uptake and decomposition. The forcing functions which were considered in the model are temperature, radiation, volume of wastewater, P concentration, contact time, flow rate and the adsorbent (i.e., alum sludge). The model results revealed that up to 72% of the SRP can be removed through adsorption process whereas the uptake by plants is about 20% and the remaining processes such as microbial P utilization and decomposition, accounted for 7% SRP removal based on the mass balance calculations. The results obtained indicate that the model can be used to simulate outflow SRP concentration, and it can also be used to estimate the amount of P removed by individual processes in the VFCW using alum-sludge as a substrate.

  17. Limites e possibilidades do ensino à distância (EaD na educação permanente em saúde: revisão integrativa

    Directory of Open Access Journals (Sweden)

    Adriane das Neves Silva

    2015-04-01

    Full Text Available Trata-se de um estudo sobre o uso do ensino a distância (EaD como uma estratégia de ensino na educação permanente em saúde (EPS, que teve como objetivo identificar e analisar os limites e possibilidades do uso da EaD na EPS. Estudo de revisão integrativa. O resultado aponta que a EaD é uma estratégia inovadora possível e potencial para a EPS, facilitando o desenvolvimento da aprendizagem dentro ou fora da instituição de saúde, porém é evidente a escassez de pesquisas na área. As limitações para a realização dos programas estão relacionadas à variável tempo, preparação para lidar com as tecnologias e importância do tutor como facilitador da aprendizagem. Conclui-se que o uso da EaD tem tido uma importante contribuição para o desenvolvimento dos recursos humanos em saúde, seja no processo de formação e/ou no processo contínuo de conhecimento.

  18. Effect of TiO2 nanoparticles on UASB biomass activity and dewatered sludge.

    Science.gov (United States)

    Yadav, Tushar; Mungray, Alka A; Mungray, Arvind K

    2017-02-01

    The accumulation of the nanowastes in the wastewater treatment plants has raised several concerns; therefore, it is an utmost priority to study the nanoparticle (NP) toxicity in such systems. In this work, the effect of TiO2 NPs on up-flow anaerobic sludge blanket (UASB) microflora and their photocatalytic effect on dewatered sludge were studied. We observed 99.98% removal of TiO2 NPs by sludge biomass within 24 h, though negligible toxicity was found up to 100 mg/L TiO2 concentration on extracellular polymeric substances (EPS), volatile fatty acid and biogas generation. The low toxicity corresponds to the agglomeration of TiO2 NPs in UASB sludge. Alterations in dewatered sludge biochemical composition and increase in cell damage were observed upon exposure to sunlight as evidenced by FTIR and fluorescent microscopy, respectively. Results suggest the negligible toxicity of TiO2 NPs on UASB biomass activity; however, once exposed to open environment and sunlight, they may exert detrimental effects.

  19. Chitosan use in chemical conditioning for dewatering municipal-activated sludge.

    Science.gov (United States)

    Zemmouri, H; Mameri, N; Lounici, H

    2015-01-01

    This work aims to evaluate the potential use of chitosan as an eco-friendly flocculant in chemical conditioning of municipal-activated sludge. Chitosan effectiveness was compared with synthetic cationic polyelectrolyte Sedipur CF802 (Sed CF802) and ferric chloride (FeCl₃). In this context, raw sludge samples from Beni-Messous wastewater treatment plant (WWTP) were tested. The classic jar test method was used to condition sludge samples. Capillary suction time (CST), specific resistance to filtration (SRF), cakes dry solid content and filtrate turbidity were analyzed to determine filterability, dewatering capacity of conditioned sludge and the optimum dose of each conditioner. Data exhibit that chitosan, FeCl₃and Sed CF802 improve sludge dewatering. Optimum dosages of chitosan, Sed CF802 and FeCl₃allowing CST values of 6, 5 and 9 s, were found, respectively, between 2-3, 1.5-3 and 6 kg/t ds. Both polymers have shown faster water removal with more permeable sludge. SRF values were 0.634 × 10¹², 0.932 × 10¹² and 2 × 10¹² m/kg for Sed CF802, chitosan and FeCl₃respectively. A reduction of 94.68 and 87.85% of the filtrate turbidity was obtained with optimal dosage of chitosan and Sed CF802, respectively. In contrast, 54.18% of turbidity abatement has been obtained using optimal dosage of FeCl₃.

  20. Enhancement of dewatering performance of digested paper mill sludge by chemical pretreatment

    Science.gov (United States)

    Lin, Y. Q.; Zeng, C.; Wu, H. H.; Zeng, B. X.

    2016-08-01

    The wide application of anaerobic digestion (AD) for waste sludge results in a huge amount of digested sludge, while the appropriate reuse of digested sludge depends on effective solid-liquid separation. Thus, chemical (acid/alkali) pretreatment effects on dewaterability of digested paper mill sludge (DPMS) for better downstream reuse based on enhanced solid- liquid separation were investigated in this research. The dewatering properties of paper mill sludge (PMS) were also investigated to elucidate the impact of AD on sludge dewaterability. The results indicated that a higher DPMS dewaterability was noted with acid pretreatment (pH5). A 41.37% moisture content and 74.41% dewatering efficiency were determined for DPMS after acid (pH5) pretreatment within 25 min. In addition, a 7.13 mg•g-1 VSS of extracellular polymeric substances (EPS) and 101.50 μm of average particle size were observed. It was also observed that both EPS concentrations and particle sizes were key parameters influencing DPMS dewaterability. Lower EPS concentrations with larger average particle sizes contributed to enhanced sludge dewaterability. Moreover, dewaterability of PMS was higher than that of DPMS, which illustrated that AD would decrease the sludge dewaterability.

  1. Investigation of Parameters Affecting Gypsum Dewatering Properties in a Wet Flue Gas Desulphurization Pilot Plant

    DEFF Research Database (Denmark)

    Hansen, Brian Brun; Kiil, Søren

    2012-01-01

    Wet flue gas desulphurization (FGD) plants with forced oxidation, installed at coal and oil fired power plants for removal of SO2(g), must produce gypsum of high quality. However, quality issues such as an excessive moisture content, due to poor gypsum dewatering properties, may occur from time...... to time. In this work, the particle size distribution, morphology, and filtration rate of wet FGD gypsum formed in a pilot-scale experimental setup, operated in forced oxidation mode, have been studied. The influence of holding tank residence time (10–408 h), solids content (30–169 g/L), and the presence...... of impurities (0.002 M Al2F6; 50 g quartz/L; 0.02 M Al3+, and 0.040 M Mg2+) were investigated. In addition, slurry from a full-scale wet FGD plant, experiencing formation of flat shaped crystals and poor gypsum dewatering properties, was transferred to the pilot plant to test if the plant would now start...

  2. Performance evaluation of existing wedgewater and vacuum-assisted bed dewatering systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, B.J.; Cardenas, R.R.; Gee, C.S.; Bandy, J.T.

    1992-01-01

    Many Army wastewater treatment plants (WWTPs) use conventional sand drying beds to dewater sludge. However, sand-drying is slow, and requires a large land area commitment and manual sludge removal. Outdoor sand-drying beds are vulnerable to weather conditions and operational problems associated with sand-media and underdrain clogging. Successful new technologies for sludge treatment in small-scale WWTPs include wedgewater beds (WBs), vacuum-assisted beds (VABs) and reed-bed systems. As operator of over 100 small WWTPs, the Army has an interest in such cost effective and technically efficient sludge-dewatering systems. This study compiled operational data from commercial WWTPs with existing WBs and VABs to evaluate their potential for Army use. Generally. WBs were found to be easier to operate and maintain than VABs. WBs also showed fewer media-and underdrain-clogging problems when high-pressure hoses were used to clean the media, and when tiles were kept free from damage. VABs were preferred by smaller plants that required a lower target solids rate. Most problems with both systems were associated with poor media cleaning, front-end loader damage, and engineering errors.

  3. Bioelectrochemical desalination and electricity generation in microbial desalination cell with dewatered sludge as fuel.

    Science.gov (United States)

    Meng, Fanyu; Jiang, Junqiu; Zhao, Qingliang; Wang, Kun; Zhang, Guodong; Fan, Qingxin; Wei, Liangliang; Ding, Jing; Zheng, Zhen

    2014-04-01

    Microbial desalination cells (MDCs) with common liquid anodic substrate exhibit a slow startup and destructive pH drop, and abiotic cathodes have high cost and low sustainability. A biocathode MDC with dewatered sludge as fuel was developed for synergistic desalination, electricity generation and sludge stabilization. Experimental results indicated that the startup period was reduced to 3d, anodic pH was maintained between 6.6 and 7.6, and high stability was shown under long-term operation (300d). When initial NaCl concentrations were 5 and 10g/L, the desalinization rates during stable operation were 46.37±1.14% and 40.74±0.89%, respectively. The maximum power output of 3.178W/m(3) with open circuit voltage (OCV) of 1.118V was produced on 130d. After 300d, 25.71±0.15% of organic matter was removed. These results demonstrated that dewatered sludge was an appropriate anodic substrate to enhance MDC stability for desalination and electricity generation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Dewatering e bonifica dell’ area ˝ex Whitehead Motofides˝ (Pisa, Italia

    Directory of Open Access Journals (Sweden)

    Nicola Conti

    2014-12-01

    Full Text Available In 2007 the activities for the remediation of the “ex-Whitehead Motofides area” (in Marina di Pisa, Italy started. In order to allow the contaminated soil excavation in dry conditions a dewatering system was necessary. The water pumped through this system was then treated in an adequate plant. Acque Industriali realized and managed the whole system. The dewatering system was made of suction pins fixed to a depth of 5.5 m, connected by a junction manifold to the suction and booster vacuum assisted pump, which allowed the groundwater release toward the plant. The treatment plant, entirely designed by Acque Industriali and called ITAM (Impianto di Trattamento Acque di Falda Mobile, which means movable groundwater treatment, was realized and set up at the end of 2008. It consisted of a pre-treatment section, made of reinforced concrete, prefabricated nitrogen sweep elements, and a physical chemical treatment plant, in a continuous loop, completely made on skid. The plant, with 25 m3/h of maximum potential, was able to remove possible sedimentable or in suspension material particles from water, iron, manganese, residual organic substances such as hydrocarbons, solvents (chlorinated and not, PCBs, and partly heavy metals. Totally, 98,167 m3 of groundwater were managed in about 25 months of activity. The analytic input and output results confirmed extremely high and satisfactory pollutant removal efficiency. The concentration values of the pollutants, in fact, were always lower than the limits imposed by law.

  5. The effect of chemical, physical and enzymatic treatments on the dewatering of tar sands tailings

    Energy Technology Data Exchange (ETDEWEB)

    Theriault, Y.; Masliyah, J.H.; Fedorak, P.M.; Vazquez-Duhalt, R.; Gray, M.R. [University of Alberta, Edmonton, AB (Canada). Dept. of Chemical Engineering

    1995-09-01

    Fine tailings (with solids {lt} 106{mu}m) from hot-water extraction of the Athabasca tar sands were subjected to thermal, physical, chemical and enzymatic treatments in an attempt to modify the dewatering characteristics of the solid particles. A low-speed centrifuge at circa 1500 relative centrifugal force for 15 h was used to accelerate the sedimentation of the solids, and allowed comparison of the ultimate concentration of solids after the various treatments. Fine tailings were subjected to thermal treatment, sonication and modification of the water chemistry. Although the rate of sedimentation was affected by these treatments, the ultimate volume fraction of solids after centrifuging was about 0.3 (50-55 wt% solids). Extraction of the tailings to remove bitumen, humins and other organic components also failed to change the ultimate solids concentration. Oxidation of the organic material in the tailings by hydrogen peroxide in Fenton`s reagent, and enzymatic oxidation with lignin peroxidase, manganese peroxidase, cytochrome c, horseradish peroxidase and cowpea peroxidase gave no significant effect on the volume fraction of solids in the sediment after centrifugation. The observation that all of these treated samples gave an ultimate volume fraction of solids of about 0.3 indicated that bitumen, adsorbed organic matter and salts had little effect on the ultimate dewatering of tailings. 26 refs., 3 figs., 5 tabs.

  6. Isolation and Characterization of Polyacrylamide-Degrading Bacteria from Dewatered Sludge

    Directory of Open Access Journals (Sweden)

    Feng Yu

    2015-04-01

    Full Text Available Polyacrylamide (PAM is a water-soluble polymer that is widely used as a flocculant in sewage treatment. The accumulation of PAM affects the formation of dewatered sludge and potentially produces hazardous monomers. In the present study, the bacterial strain HI47 was isolated from dewatered sludge. This strain could metabolize PAM as its sole nutrient source and was subsequently identified as Pseudomonas putida. The efficiency of PAM degradation was 31.1% in 7 days and exceeded 45% under optimum culture condition (pH 7.2, 39 °C and 100 rpm. The addition of yeast extract and glucose improved the bacterial growth and PAM degradation. The degraded PAM samples were analyzed by gel-filtration chromatography, Fourier transform infrared and high-performance liquid chromatography. The results showed that high-molecular-weight PAM was partly cleaved to small molecular oligomer derivatives and part of the amide groups of PAM had been converted to carboxyl groups. The biodegradation did not accumulate acrylamide monomers. Based on the SDS-PAGE and N-terminal sequencing results, the PAM amide groups were converted into carboxyl groups by a PAM-induced extracellular enzyme from the aliphatic amidase family.

  7. Characterization of a bioflocculant from potato starch wastewater and its application in sludge dewatering.

    Science.gov (United States)

    Guo, Junyuan; Zhang, Yuzhe; Zhao, Jing; Zhang, Yu; Xiao, Xiao; Wang, Bin; Shu, Bi

    2015-07-01

    A bioflocculant was produced by using potato starch wastewater; its potential in sludge dewatering and potato starch wastewater treatment was investigated. Production of this bioflocculant was positively associated with cell growth, and a highest value of 0.81 g/L was obtained. When incubated with this bioflocculant, dry solids (DS) and specific resistance to filtration (SRF) of typical wastewater activated sludge reached 20.8% and 3.9 × 10(12) m/kg, respectively, which were much better than the ones obtained with conventional chemical flocculants. Sludge dewatering was further improved when both the bioflocculant and conventional polyacrylamide (PAM) were used simultaneously. With potato starch wastewater, chemical oxygen demand (COD) and turbidity removal rates could reach 52.4 and 81.7%, respectively, at pH value of 7.5 when the bioflocculant dose was adjusted to 30 mg/L; from a practical standpoint, the removal of COD and turbidity reached 48.3 and 72.5%, respectively, without pH value adjustment.

  8. Bio filtration of smell emission generated by biological sludge dewatering; Biofiltrazione di emissioni maleodoranti generate dalla disidratazione di fanghi biologici

    Energy Technology Data Exchange (ETDEWEB)

    Collivignarelli, C. [Brescia Univ. (Italy). Dipt. di Ingegneria Civile. Facolta' di Ingegneria; Riganti, V. [Pavia Univ. (Italy). Dipt. di Chimica Generale; Berri, A. [Fondazione S. Maugeri, Pavia (Italy); Colombi, A. [Milan Univ. (Italy). Clinica del Lavoro L. Devoto; Conti, F. [Pavia Univ. (Italy). Dipt. di Ingegneria Idraulica e Ambientale; Decarro, C. [Pavia Univ. (Italy). Ist. di Farmacologia; Del Frate, G. [Pavia Univ. (Italy). Dipt. di Ecologia del Territorio e degli Ambienti Terrestri. Ist. di Micologia Medica; Gerla, R. [Ecodeco SpA, Loc. Cassinazza, Giussago, PV (Italy)

    1999-06-01

    This work presents the results of a pilot scale experience about smelling air treatment by means of bio filtration. The odor emission is generated in a dewatering process of the sludge derived from an industrial wastewater biological treatment. The study was carried out by chemical, chemical-physical, microbiological and organoleptic (olfactometric) analysis. Hydrogen sulfide is the main pollutant removed by this treatment; for this parameter a mass balance was developed to validate the collected data. The result was also compared with the ones of a similar treatment experience carried out on a flue gas derived from a different source (pretreatment of liquid waste). This procedure confirmed the good treatmen capacity of the bio filtration process. [Italian] Quasta relazione illustra i risultati di una esperienza su scala pilota di trattamento mediante biofiltrazione di aria maleodorante. L'emissione odorosa e' generata dal trattamento di disidratazione dei fanghi prodotti da un processo di depurazione biologica dei reflui industriali. Lo studio e' stato condotto mediante l'esecuzione di analisi chimiche e chimico-fisiche, microbiologiche e organolettiche (olfattometriche). Il principale inquinante abbattuto dal trattamento e' il solfuro di idrogeno; su questo parametro e' stato impostato un bilancio di massa per la validazione degli ottimi risultati rilevati. I dati raccolti sono anche confrontati con gli esiti di un'analoga esperienza di trattamento effettuata su un refluo di origine diversa (esalazioni da pretrattamento di rifiuti liquidi) confermando la sostanziale capacita' di trattamento del sistema di biofiltrazione.

  9. Correlation of wood-based components and dewatering properties of waste activated sludge from pulp and paper industry.

    Science.gov (United States)

    Kyllönen, H; Lehto, J; Pirkonen, P; Grönroos, A; Pakkanen, H; Alén, R

    2010-01-01

    Large amounts of wet sludge are produced annually in municipal and industrial wastewater treatment. Already in pulp and paper industry, more than ten million tons of primary sludge, waste activated sludge, and de-inking sludge is generated. Waste activated sludge contains large quantities of bound water, which is difficult to dewater. Low water content would be a matter of high calorific value in incineration but it also has effects on the volume and the quality of the matter to be handled in sludge disposal. In this research waste activated sludges from different pulp and paper mills were chemically characterised and dewatered. Correlations of chemical composition and dewatering properties were determined using multivariate analysis. Chemical characterisation included basic sludge analysis, elementary analysis and analysis of wood-based components, such as hemicelluloses and lignin-derived material. Dewatering properties were determined using measurements of dry solids content, flux and flocculant dosage. The effects of different variables varied according to the response concerned. The variables which were significant regarding cake DS increase in filtration or centrifugation and flocculant dosage needed in filtration were different from those which were significant regarding flux.

  10. A avaliação vista sob o aspecto da educação a distância La evaluación bajo el aspecto de la educación a distancia Evaluation from an EAD perspective

    Directory of Open Access Journals (Sweden)

    Maurício Rosa

    2006-03-01

    Full Text Available Este artigo trata da avaliação como um aspecto bastante relevante para a educação em geral, que também deve ser pensado e discutido frente à Educação a Distância (EAD. Assim, a partir de nossa experiência como professores e tendo por contexto um curso realizado totalmente à distância, analisamos algumas interações ocorridas ao longo do curso, que foi desenvolvido tendo como norte a teoria educacional construcionista. Valemo-nos também desta teoria para elaborar nossas idéias a respeito do caráter da avaliação frente a uma concepção formativa, em um ambiente de EAD, o qual valorizou todos os tipos de interação. Então, aliamos o Construcionismo1 à Avaliação Formativa que visa ao aperfeiçoamento do processo de aprendizagem do aluno em vez de buscar medir o que este aprendeu.Este artículo trata de la evaluación como un aspecto muy destacado en la educación, y que debe ser discutido en el marco de la Educación a Distancia (EaD. Luego, con base en nuestra experiencia como docentes y en el marco de un curso realizado totalmente a distancia, investigamos algunas interacciones ocurridas a lo largo del curso que se desarrolló teniendo en cuenta la teoría educacional Construccionista. Empleamos también esta teoría al elaborar nuestras ideas respecto al carácter de la evaluación frente a una concepción formativa, en un ambiente de EaD, en el que se valoro a todo tipo de interacciones. De hecho, unimos el Construccionismo a la Evaluación Formativa buscando el mejor desarrollo del proceso de aprendizaje en lugar de buscar una medida de aquello que un alumno pueda haber aprendido.This paper presents the assessment as an aspect, sufficiently important for the education in general, that also it must be thought and be discuss in front of the Distance Education. Thus, from our experience as professors and having for context a course fulfilled totally at distance, we analyzed some interactions that occurred during the course

  11. Environment-friendly Dredging with Geotextile Tubes for Dewatering and Volume Reduction of Sediments in Lake and Reservoir%环保疏浚联合土工管袋用于湖库底泥的脱水减容

    Institute of Scientific and Technical Information of China (English)

    王松; 魏新庆; 王立彤

    2011-01-01

    The engineering case of using environment-friendly dredging with geotextile tubes for dredging, dewatering and volume reduction of sediments in Hangu Sewage Reservoir is introduced. It mainly includes design of environment-friendly dredging, preparation of dewatering and volume reduction site, selection of the geotextile tubes, filling of geotextile tubes, dosing of the flocculant and so on.Through the design and whole process practice of this engineering, the design parameters and process of environment-friendly dredging with geotextile tubes for dewatering and volume reduction of sediments in lake and reservoir are found to lay the foundation for its large-scale application in the future.%介绍了汉沽污水库现场试验工程采用环保疏浚联合土工管袋的方式,对底泥进行清淤和脱水减容的工程实例,主要内容包括环保疏浚设计、脱水减容场地准备、土工管袋选型、土工管袋充填、絮凝剂投加等.通过对本工程的设计和全过程跟踪实践,摸索出环保疏浚联合土工管袋用于湖库底泥脱水减容的设计参数和操作流程,为今后规模化应用奠定了基础.

  12. Parallel studies on dewatering and conditioning of an alum sludge and an aluminium hydroxide suspension.

    Science.gov (United States)

    Papavasilopoulos, E N; Bache, D H

    2001-01-01

    The paper shows a comparison between properties of an alum sludge gained from the coagulation of a coloured water with those of a suspension of aluminium hydroxide at a concentration equivalent to the coagulant fraction within the sludge. Background information is provided on composition and aspects of the source floc. The comparisons embraced floc size, polymer adsorption, and dewatering parameters including specific resistance to filtration, capillary suction time and the equilibrium moisture content under pressure. In all cases, there were strong similarities in the behaviour of the two suspensions. It is suggested that such features emanate from a common fractal structure within the source floc, whose fractal index (approximately/= 1) has been found to be insensitive to the composition of the floc.

  13. Estudo analítico de publicações sobre EaD na educação especial como ferramenta pedagógica

    Directory of Open Access Journals (Sweden)

    Dulcegleika Villas Boas Sartori

    2017-06-01

    Full Text Available O presente estudo teve como objetivo analisar a educação à distância no Brasil e seu uso na educação especial como inclusão escolar. Para tanto foi realizado um estudo e levantamento bibliográfico sobre o assunto em periódicos, revistas científicas nacionais e livros para a presente discussão. Observa-se que a educação à distância é uma modalidade em constante crescimento no Brasil, e as novas tecnologias de informação e comunicação podem contribuir na educação, sendo uma possibilidade de inclusão no processo de ensino e aprendizagem. Entretanto, a inclusão dos sujeitos com alguma deficiência, ainda está acontecendo, pois diante das possibilidades e perspectivas, e dos avanços, requer maior participação dos agentes públicos através de políticas públicas. Para que a educação especial e a inclusão escolar aconteçam de forma efetiva, se faz necessário que o professor possa permanecer na formação continuada, com isso, atender o deficiente nos processos de ensino e aprendizagem, ou seja, o professor educador deve estar em constante aprendizado. A educação à distância tem se mostrado uma alternativa com bons resultados na formação do professor da educação especial. Porém, diante do levantamento, observamos que não há relatos do uso da EaD como possibilidade na educação especial para acesso e inclusão dos sujeitos com alguma deficiência, mas para a formação inicial e continuada do professor e educador a EaD tem sido utilizada como meio possível para alcançarmos profissionais com mais habilidades e competências na educação especial.

  14. Characteristics of dewatering induced drawdown curve under blocking effect of retaining wall in aquifer

    Science.gov (United States)

    Wu, Yong-Xia; Shen, Shui-Long; Yuan, Da-Jun

    2016-08-01

    For deep excavation pits that require the pumping of confined groundwater, a combination of a retaining wall and dewatering with large-diameter wells is usually adopted during excavation to improve safety. Since a retaining wall has a much lower hydraulic conductivity than the surrounding material in the aquifer, blocking of seepage to prolong the seepage path of the groundwater outside of the pit is effective. The retaining walls used during excavation dewatering cause hydraulic head drawdown inside the pit much faster than outside the pit. Thus, difference in hydraulic head between inside and outside of the pit increases. To investigate the mechanism of the blocking effect, numerical simulation using the finite difference method (FDM) was conducted to analyze the effects of pumping in the pit. The FDM results show that drawdown varies along the depth of the confined aquifer. The influence factors of drawdown inside and outside the pit include insertion depth of retaining walls, anisotropy of a confined aquifer and screen length of pumping wells. In addition, FDM results also show that the drawdown-time curve can be divided into four stages: in Stage I, drawdown inside the pit is very small and outside the pit it is almost zero; in Stage II, drawdown increases quickly with time; in Stage III, the drawdown curve is parallel to the Cooper-Jacob curve on semi-log axes; and in Stage IV, the drawdown becomes constant. These characteristics of the drawdown curve under the blocking effect of a retaining wall in an aquifer provide a way of estimating hydrogeological parameters according to pumping test results.

  15. Mesures d’impact des régulations dans la construction d’un enseignement à distance (EAD en initiation à l’entomologie

    Directory of Open Access Journals (Sweden)

    Jacques Mignon

    2006-01-01

    Full Text Available Le cours « Initiation à l’entomologie » de la FuSaGx (Belgique intègre une formation EAD et des TP en laboratoires. Son développement progressif sur deux années rend intéressante la description de l’influence des phases d’expérimentation-régulation sur l’évolution des caractéristiques du cours. Une méthode de recueil des avis des étudiants a été utilisée, les résultats ont été analysés et confrontés à d’autres indicateurs. Ces résultats, bien qu’ayant évolué positivement, restent mitigés et confirment la difficulté de rendre efficace un cours à distance. La spirale « expérimentation-régulation-évaluation postrégulatoire » est à poursuivre pour adapter ce cours aux objectifs initiaux ainsi qu’aux besoins des étudiants.

  16. The Practice and Explore of Dewatering Slag Tailings by Using Ceramic Filter%陶瓷过滤机应用于炉渣选矿尾矿脱水的实践与探索

    Institute of Scientific and Technical Information of China (English)

    谢杰; 马松勃

    2014-01-01

    陶瓷过滤机是一种应用较广的脱水设备。本文概述了铜炉渣选矿尾矿应用陶瓷过滤机脱水的生产状况,发现了影响系统生产的各类问题并提出了改进措施;探索研究了工艺、设备及物料性质对选矿尾矿过滤产能的影响,在最佳工艺条件下,陶瓷过滤机产能可达291 kg/(m2· h)。%Ceramic filter is widely used as a kind of dewatering equipment . This paper summarized the pro-duction situation of dewatering the slag beneficiation tailings of copper by using ceramic filter , some prob-lems that affected the system production were found and the corresponding improvement measures were put forward . And also found that the process , equipment and material properties influenced the filter ca-pacity , under the condition of optimum process , ceramic filter capacity can up to 291 kg/( m2.h) .

  17. Transport phenomena in the crystallization of lysozyme by osmotic dewatering and liquid-liquid diffusion in low gravity

    Science.gov (United States)

    Todd, Paul; Sportiello, Michael G.; Gregory, Derek; Cassanto, John M.; Alvarado, Ulises A.; Ostroff, Robert; Korszun, Z. R.

    1993-01-01

    Two methods of protein crystallization, osmotic dewatering and liquid-liquid diffusion, like the vapor diffusion (hanging-drop and sessile-drop) methods allow a gradual approach to supersaturation conditions. The crystallization of hen egg-white lysozyme, an extensively characterized protein crystal, in the presence of sodium chloride was used as an experimental model with which to compare these two methods in low gravity and in the laboratory. Comparisons of crystal growth rates by the two methods under the two conditions have, to date, indicated that the rate of crystal growth by osmotic dewatering is nearly the same in low gravity and on the ground, while much faster crystal growth rates can be achieved by the liquid-liquid diffusion method in low gravity.

  18. 含油含醇污泥脱水性能分析与应用%Analysis and application of dewatering performance of sludge containing alcohol and oil

    Institute of Scientific and Technical Information of China (English)

    吴新民; 曹岗; 刘昂; 王海蒙; 姚炬

    2013-01-01

    Gas field exploitation often produce some oil-alcohol-containing components of the sludge generated in the process of gathering and transportation complex, direct emissions will lead to the pollution of the surrounding environment. Experimental research concentrated on the settlement of oily alcohol-containing sewage to reduce the emissions of harmful sludge to improve the treatment process, sludge samples, the experimental determination of the composition and particle size distribution analysis of the reasons for the poor separation, oil-containing alcohol to a gas field in northern Shaanxi; sludge dewatering performance, screening effective flocculant, to determine the best complex solutions and the dosage. Experimental results show that; mass concentration of 500 mg/L of PAC and 30 mg/L SC—3 formula composite the flocculant sludge dewatering performance sedimentation treatment concentrated oil-alcohol-containing sludge volume is reduced, the water content rate decreased, and the processing time is shortened. Field application test; formulation can effectively improve the treatment process and play a good role in the protection of the gas field environment.%在气田开采、集输过程中产生的含油含醇污泥成分复杂,直接排放将导致周围环境污染.为减少有害污泥排放,改善处理工艺流程,以陕北某气田含油含醇污泥为样品,实验测定组分与粒度分布,分析分离效果差的原因;通过浓缩沉降实验研究含油含醇污泥脱水性能,筛选有效絮凝剂,确定最佳复配方案及投加剂量.实验结果表明:以质量浓度分别为500 mg/L的PAC与40 mg/L的SC-3为配方的复合絮凝剂具有良好的污泥脱水性能,浓缩沉降处理后含油含醇污泥体积缩小、含水率下降,且处理时间缩短.现场应用结果表明:文中配方可有效改善处理工艺流程,对保护气田环境起到良好作用.

  19. Effect of Long-Term Freezing and Freeze–Thaw Cycles on Indigenous and Inoculated Microorganisms in Dewatered Blackwater

    DEFF Research Database (Denmark)

    Gunnarsdottir, Ragnhildur; Müller, Karoline; Jensen, Pernille Erland

    2012-01-01

    coliforms, fecal streptococci, and antibiotic-resistant (AR) bacteria, and inoculated Salmonella Enteriditis and E. coli bacteriophage ΦX174 in dewatered blackwater. At the end of the long-term freezing experiment (10 months), an MPN recovery study was done, including the microbial groups that had shown....... Bacteriophages showed limited reduction during the long-term freezing. Repeated freezing and thawing increased the reduction of all tested microbial groups markedly....

  20. Occurrence and discharge of pharmaceuticals and personal care products in dewatered sludge from WWTPs in Beijing and Shenzhen

    Directory of Open Access Journals (Sweden)

    Rui Dong

    2016-03-01

    Full Text Available This study mainly focused on the occurrence of pharmaceutical and personal care products (PPCPs in sewage dewatered sludge and their discharges through sludge disposal from wastewater treatment plants (WWTPs. The data were obtained and calculated from seven PPCPs in dewatered sludge collected from 12 WWTPs in two typical cities, Beijing and Shenzhen in China. Four of seven PPCPs, diclofenac acid, carbamazepine, mefenamic acid and N,N-diethyl-m-toluamide were detectable in dewatered sludge from Beijing and Shenzhen with concentration up to 4240, 11,060, 92 and 219 μg/kg respectively. While, the other three compounds, trimethoprim, chloramphenicol and bezafibrate were not detected in collected samples from these two cities. The highest discharge of diclofenac acid and carbamazepine were 1023 g/d and 494 g/d respectively. In addition, the total discharge of these four detected PPCPs from each plant ranged from 5 to 1092 g/d in Beijing and 4–497 g/d in Shenzhen. Thus, PPCP discharge through sludge disposal cannot be neglected, and further research on transfer of PPCPs during sludge disposal onto agriculture land and influence of sludge application is required and essential.

  1. GESTÃO DE RECURSOS DO EAD: COMO ADEQUAR AS TECNOLOGIAS AOS PERFIS DE ASSIMILAÇÃO

    Directory of Open Access Journals (Sweden)

    Lucia Helena Aponi Sanchez

    2015-08-01

    Full Text Available Online Distance Learning managers face the dilemma of using new Information and Communication Technologies (ICT effectively and efficiently. On the other hand, learning theories, among them Cognitive Psychology, describe how the media and processes affect individual learning. Based on these theories, we propose that individuals can be classified according to their assimilation profile in two groups: Analytical Assimilation and Relational Assimilation. We analyze how different distance education technologies, classified as Textual, Audio, Interactive (synchronous and Collaborative (asynchronous, affect the perceived effectiveness of technology learning of each group. Empirical evidence support that each group perceives differently technologies types in regard to its effectiveness in learning. Important managerial implications for the effective and efficient use of resources in distance education are proposed.

  2. Syneresis cracks: subaqueous shrinkage in argillaceous sediments caused by earthquake-induced dewatering

    Science.gov (United States)

    Pratt, Brian R.

    1998-04-01

    Syneresis cracks, often confused with subaerial desiccation phenomena, are traditionally ascribed to subaqueous shrinkage whereby salinity changes caused deflocculation of clay. This and other previously proposed mechanisms fail to account for their occurrence in low-energy, typically non-evaporitic facies, stratigraphically sporadic distribution, intrastratal formation under shallow burial depths, variation in morphology, degree of contraction, generation of sedimentary dikelets as crack fills, and deformation of dikelets and enclosing layers. Instead, it is suggested that ground motion from strong synsedimentary earthquakes caused argillaceous sediments to dewater, interbedded sands and silts to be almost simultaneously liquefied and injected into the resulting fissures, and then these dikelets to be distorted. Comparative rarity of syneresis cracks in Phanerozoic versus Precambrian marine strata is considered to be primarily an evolutionary consequence of theological changes caused by increased organic binding of clay flocs in the water column, greater input of organic matter into the sediment, and the diversification of sediment-dwelling bacteria and meiofauna in Phanerozoic deposits.

  3. Brown Coal Dewatering Using Poly (Acrylamide-Co-Potassium Acrylic Based Super Absorbent Polymers

    Directory of Open Access Journals (Sweden)

    Sheila Devasahayam

    2015-09-01

    Full Text Available With the rising cost of energy and fuel oils, clean coal technologies will continue to play an important role during the transition to a clean energy future. Victorian brown coals have high oxygen and moisture contents and hence low calorific value. This paper presents an alternative non evaporative drying technology for high moisture brown coals based on osmotic dewatering. This involves contacting and mixing brown coal with anionic super absorbent polymers (SAP which are highly crossed linked synthetic co-polymers based on a cross-linked copolymer of acryl amide and potassium acrylate. The paper focuses on evaluating the water absorption potential of SAP in contact with 61% moisture Loy Yang brown coal, under varying SAP dosages for different contact times and conditions. The amount of water present in Loy Yang coal was reduced by approximately 57% during four hours of SAP contact. The extent of SAP brown coal drying is directly proportional to the SAP/coal weight ratio. It is observed that moisture content of fine brown coal can readily be reduced from about 59% to 38% in four hours at a 20% SAP/coal ratio.

  4. Dewatering of Chlorella pyrenoidosa using diatomite dynamic membrane: filtration performance, membrane fouling and cake behavior.

    Science.gov (United States)

    Zhang, Yalei; Zhao, Yangying; Chu, Huaqiang; Zhou, Xuefei; Dong, Bingzhi

    2014-01-01

    The diatomite dynamic membrane (DDM) was utilized to dewater Chlorella pyrenoidosa of 2 g dry weight/L under continuous-flow mode, whose ultimate algae concentration ranged from 43 g to 22 g dry weight/L of different culture time. The stable flux of DDM could reach 30 L/m(2) h over a 24 h operation time without backwash. Influences of extracellular organic matters (EOM) on filtration behavior and membrane fouling were studied. The DDM was divided into three sub-layers, the slime layer, the algae layer and the diatomite layer from the outside to the inside of the cake layer based on components and morphologies. It was found that EOM caused membrane fouling by accumulating in the slime and algae layers. The DDM intercepted polysaccharides, protein-like substances, humic-like substances and some low-MW organics. Proteins were indicated the major membrane foulants with increased protein/polysaccharide ratio from the slime layer to the diatomite layer as culture time increased. This method could be applied to subsequent treatment of microalgae coupling technology of wastewater treatment or microalgae harvesting for producing biofuel. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. THE ROLE OF PRESS FABRIC PRESSURE UNIFORMITY AND PORE SIZE ON DEWATERING AND REWET DURING PRESSING

    Institute of Scientific and Technical Information of China (English)

    Xiaolin Fan; Mary Toney; Jorgen Gullbrand; Fawaad Qamar

    2004-01-01

    New procedures for measuring the pressure uniformity and pore size of press fabrics have been developed to study their role in the dewatering efficiency of a wet paper sheet and fabric system during pressing. The press nip profile of a single nip can be simulated in the laboratory using a custom built Servo-hydraulic Press Nip Simulator (SPNS) and is used to evaluate the final dryness and rewet of a handsheet with press fabric(s). Pressure uniformity can be measured with a flexible high-resolution transducer and pore size; both tests measured using water as the fluid are performed on compressed press fabric samples. A strong correlation is found between pressure uniformity parameters, mean flow pore size and final dryness for different sheets. Rewet is measured "directly" using a tracer fluid in the press fabric in our SPNS tester. Preliminary results indicate a significant reduction in rewet for some sheets with the use of an anti-rewet layer in combination withcertain press fabric designs.

  6. Mine dewatering and impact assessment in an arid area: Case of Gulf region.

    Science.gov (United States)

    Yihdego, Yohannes; Drury, Len

    2016-11-01

    Analytical and empirical solution coupled with water balance method were used to predict the ground water inflow to a mine pit excavated below the water table, final pit lake level/recovery and radius of influence, through long-term and time variant simulations. The solution considers the effect of decreased saturated thickness near the pit walls, distributed recharge to the water table and upward flow through the pit bottom. The approach is flexible to accommodate the anisotropy/heterogeneity of the real world. Final pit void water level was assessed through scenarios to know whether it will be consumed by evaporation and a shallow lake will form or not. The optimised radius of influence was estimated which is considered as crucial information in relation to the engineering aspects of mine planning and sustainable development of the mine area. Time-transient inflow over a period of time was estimated using solutions, including analytical element method (AEM). Their primary value is in providing estimates of pit inflow rates to be used in the mine dewatering. Inflow estimation and recovery helps whether there is water to supplement the demand and if there is any recovery issue to be dealt with in relation to surface and groundwater quality/eco-system, environmental evaluations and mitigation. Therefore, this method is good at informing decision makers in assessing the effects of mining operations and developing an appropriate water management strategy.

  7. 电渗与真空排水法降低填料含水率的比较研究%Comparative Research on Decreasing Water Content of Filler by Electro-Osmosis and Vacuum Dewatering

    Institute of Scientific and Technical Information of China (English)

    王甦达; 费维水; 唐正光; 吴培关

    2011-01-01

    Based on contrast experiments, this paper researches the efficiency of electro-osmosis and vacuum de-watering, two methods for water content decreasing of filler. Analysis of experiments indicates that the efficiency of dewatering by electro-osmosis is higher than that by vacuum dewatering in fine grained soil, and it's almost the same in coarse grained soil, but the electricity consumption by electro-osmosis is much less than that by vacuum dewatering. The conclusion given in this article may be helpful to choose proper scheme for decreasing water content.

  8. Ground-water conditions and effects of mine dewatering in Desert Valley, Humboldt and Pershing Counties, northwestern Nevada, 1962-91

    Science.gov (United States)

    Berger, D.L.

    1995-01-01

    Desert Valley is a 1,200-square-mile, north- trending, structural basin, about 30 miles northwest of Winnemucca, Nevada. Unconsolidated basin-fill deposits exceeding 7,000 feet in thickness constitute the primary ground-water reservoir. Dewatering operations at an open-pit mine began in the Spring of 1985 in the northeast part of Desert Valley. Ground-water withdrawal for mine dewatering in 1991 was greater than three times the estimated average annual recharge from precipitation. The mine discharge water has been allowed to flow to areas west of the mine where it has created an artificial wetlands. This report documents the 1991 hydrologic conditions in Desert Valley and the change in conditions since predevelopment (pre-1962). It also summarizes the results of analyzing the simulated effects of open-pit mine dewatering on a basin-wide scale over time. Water-level declines associated with the dewatering have propagated north and south of the mine, but have been attenuated to the west due to the infiltration beneath the artificial wetlands. Maximum water-level declines beneath the open pits at the mine, as of Spring 1991, are about 300 feet. Changes in the hydrologic conditions since predevelopment are observed predominantly near the dewatering operations and the associated discharge lakes. General ground-water chemistry is essentially unchanged since pre- development. On the basis of a ground-water flow model used to simulate mine dewatering, a new equilibrium may slowly be approached only after 100 years of recovery from the time mine dewatering ceases.

  9. EADS Roadmap for Launch Vehicles

    Science.gov (United States)

    Eymar, Patrick; Grimard, Max

    2002-01-01

    still think about the future, especially at industry level in order to make the most judicious choices in technologies, vehicle types as well as human resources and facilities specialization (especially after recent merger moves). and production as prime contractor, industrial architect or stage provider have taken benefit of this expertise and especially of all the studies ran under national funding and own financing on reusable vehicles and ground/flight demonstrators have analyzed several scenarios. VEHICLES/ASTRIUM SI strategy w.r.t. launch vehicles for the two next decades. Among the main inputs taken into account of course visions of the market evolutions have been considered, but also enlargement of international cooperations and governments requests and supports (e.g. with the influence of large international ventures). 1 patrick.eymar@lanceurs.aeromatra.com 2

  10. Kinetics of nitrification in a fixed biofilm reactor using dewatered sludge-fly ash composite ceramic particle as a supporting medium.

    Science.gov (United States)

    Lee, Mong-Chuan; Lin, Yen-Hui; Yu, Huang-Wei

    2014-11-01

    A mathematical model system was derived to describe the kinetics of ammonium nitrification in a fixed biofilm reactor using dewatered sludge-fly ash composite ceramic particle as a supporting medium. The model incorporates diffusive mass transport and Monod kinetics. The model was solved using a combination of the orthogonal collocation method and Gear's method. A batch test was conducted to observe the nitrification of ammonium-nitrogen ([Formula: see text]-N) and the growth of nitrifying biomass. The compositions of nitrifying bacterial community in the batch kinetic test were analyzed using PCR-DGGE method. The experimental results show that the most staining intensity abundance of bands occurred on day 2.75 with the highest biomass concentration of 46.5 mg/L. Chemostat kinetic tests were performed independently to evaluate the biokinetic parameters used in the model prediction. In the column test, the removal efficiency of [Formula: see text]-N was approximately 96 % while the concentration of suspended nitrifying biomass was approximately 16 mg VSS/L and model-predicted biofilm thickness reached up to 0.21 cm in the steady state. The profiles of denaturing gradient gel electrophoresis (DGGE) of different microbial communities demonstrated that indigenous nitrifying bacteria (Nitrospira and Nitrobacter) existed and were the dominant species in the fixed biofilm process.

  11. From "fills" to filter : insights into the reuse of dewatered alum sludge as a filter media in a constructed wetland

    OpenAIRE

    Babatunde, A.O.; Y. Q. ZHAO; Yang, Y.; Kearney, P

    2007-01-01

    Dewatered alum sludge, a by-product of drinking water treatment plants, hitherto consigned to landfills was used to develop a novel bio-filter in form of a constructed wetland. Performance results have demonstrated the benefits of the alum sludge cakes in a lab-scale system in enhancing phosphorus (P) removal from an animal farm wastewater. Although P and organic matter were concurrently removed in the system, there was a probable “one off” release of organics from the system, and this coinci...

  12. On construction points deep well dewatering project of foundation pit%基坑深井降水工程施工要点

    Institute of Scientific and Technical Information of China (English)

    李冬

    2015-01-01

    介绍了深井降水的概念,对深井降水设计及施工前应注意的问题进行了详细说明,并对施工时降水井施工、抽水施工、土方开挖等技术作了简要阐述,提出了一些深井降水关键控制点,以确保工程的顺利进行。%The paper introduces the concept of deep well dewatering project,indicates some precautions for deep well dewatering project,illus-trates some techniques including dewatering well project,pumping construction,and earthwork excavation,and points out its key controlling points,so as to ensure its smooth construction.

  13. Capacitação em EAD para formação de agentes de preservação do patrimônio documental arquivístico da Universidade Federal do Rio Grande (FURG

    Directory of Open Access Journals (Sweden)

    Karin Christine Schwarzbold

    2015-12-01

    Full Text Available Este artigo trata do uso de ambientes virtuais de ensino-aprendizagem (AVEA na capacitação de servidores, com o objetivo de preservar o patrimônio documental da Universidade Federal do Rio Grande (FURG. Buscou-se sensibilizar os dirigentes da instituição sobre a importância da criação de um curso de capacitação na modalidade EAD, estudar a plataforma Moodle para o desenvolvimento da proposta do Curso Piloto de Noções de Arquivo na modalidade EAD e difundir noções de arquivologia como forma da preservação da memória institucional. O curso foi preparado e ministrado pela pesquisadora juntamente com um servidor da área de TI bem como uma arquivista com ampla experiência em conservação e restauração. Especialmente nesta pesquisa, a preservação da memória documental arquivística está contemplada uma vez que o curso atingiu os objetivos propostos e os alunos puderam perceber que o cuidado com a documentação se dá desde o início, a partir do momento de sua criação, e não apenas no momento em que esta passa a ser “guardada” no arquivo.

  14. Study of simple dewatering method for groundwater. Kan'i chika suii teika koho no koan

    Energy Technology Data Exchange (ETDEWEB)

    Natsume, H. (Chubu Electric Power Co. Inc., Nagoya (Japan))

    1994-05-01

    A method to construct a power distribution transformer station without using steel sheet piles was executed. In the past, when building the foundation for machinery and equipment in places where the ground-water level is high, the inflow of ground-water was prevented usually by stopping ping soil with steel sheet piles. By lowering the ground-water level, open excavation without using steel sheet pipes becomes possible. The conditions for a dewatering method are: the boring depth should be 3-5 m, the method should be easy and economical, and it should not have effects on surroundings. Taking these conditions into account, we devised a simple dewatering method by which simple wells were drilled. This method is economical because the auger screw of a pile driver can be used. Since wells are shallow, perforated polyethylene pipes serve the purpose sufficiently. Through test construction, it was confirmed that the ground-water level lowered with time (within 60 hours). On the basis of results of test construction, we determined the depth, number and arrangement of wells. This method is advantageous in that it shortens the term of construction and reduces construction cost. It is applicable to the construction of other underground structures where water replacement is necessary. 11 figs., 2 tabs.

  15. Decolorization and biodegradation of the Congo red by Acinetobacter baumannii YNWH 226 and its polymer production's flocculation and dewatering potential.

    Science.gov (United States)

    Li, Ruijing; Ning, Xun-an; Sun, Jian; Wang, Yujie; Liang, Jieying; Lin, Meiqing; Zhang, Yaping

    2015-10-01

    The strain Acinetobacter baumannii YNWH 226 was utilized to degrade Congo red (CR) under aerobic conditions. CR was employed as the sole carbon source to produce extracellular polymeric substances (EPS) used as potent bioflocculants in this strain. A total of 98.62% CR was removed during the 48-h decoloration experiments using CR (100 mg/L). A total of 83% bioadsorption and 65% biodegradation were responsible for the decoloration and degradation of CR through the strain. The bioflocculant showed high flocculation activity and dewaterability on textile dyeing sludge. A maximum flocculation of 78.62% with a minimum SBF of 3.07×10(9) s(2)/g and a CST of 58.4 s were achieved. We investigated the internal relationship between the decolorization efficiency of YNWH 226 and the flocculation activity and dewatering capacity of its EPS. The components and structure of the EPS highly influenced the decolorization efficiency of CR and the flocculation activity and dewatering capacity on sludge.

  16. CONSTRUCTION METHOD FOR LARGE-APERTURE DEWATERING WELL SEALING%大孔降水井封井工法

    Institute of Scientific and Technical Information of China (English)

    刘勇; 顾冠忠

    2012-01-01

    目前大压力水的降水井封闭一般由专业队伍施工,费用较高.采用大孔降水井封井工法,利用千斤顶压住地下水,用膨胀橡胶止水条填塞钢板与井管间的缝隙,再焊接钢板与导管的横缝,将地下水封在井下.该做法简便易行,经济实用.%At present, sealing of high-pressure dewatering well is usually carried out by professionals and the construction cost is high. Large -aperture dewatering well sealing method could successfully seal the groundwater in well by using jack to press down the groundwater and expansion rubber strip to fill the clearance between steel sheet and well tube before welding the cross joint between steel sheet and pipeline. This is a simple, economic, practical and feasible method.

  17. The assessment of human exposure to radionuclides from a uranium mill tailings release and mine dewatering effluent.

    Science.gov (United States)

    Ruttenber, A J; Kreiss, K; Douglas, R L; Buhl, T E; Millard, J

    1984-07-01

    This study provides an assessment of human exposure to radiation from a river system contaminated by radionuclides of the 238U decay series released through a dam break at a uranium mill tailings pond and by the continuous discharge of dewatering effluent from 2 uranium mines. The in vivo analyses of radionuclides in 6 Navajo Indians who lived near the river indicate no detectable elevations above background concentrations. Dose estimates for inhalation of suspended river sediment indicate a maximum annual 50-yr dose commitment of 204 mrem to the endosteum. Estimates of doses (50-yr dose commitments) from the ingestion of livestock range between 1 mrem (to liver) and 79 mrem (to bone) suggest that the major contribution to human exposure is from mine dewatering effluent that has been continuously released into the river system for many years. Although the estimated exposures do not exceed existing state or federal regulations, their magnitude justifies further measurement of radionuclides in animals and in the natural environment and the consideration of strategies to reduce radiation exposure to humans and animals.

  18. Study on Dewatering Technology for Deep Foundation Pit Along River%傍河深基坑降水技术研究

    Institute of Scientific and Technical Information of China (English)

    李芳; 王文明

    2013-01-01

    Taking 2 cases as the examples and based on the characteristics of being near to the recharging source, thick aqui-fer and strong permeability, the study was made on dewatering technology for deep foundation pit along river in the dewatering scheme selection, dewatering design, dewatering well construction and the effects on the surrounding buildings and under-ground water, in order to provide the reference to the similar projects in the area of Qiangang of Capital Steel Company.%  以首钢迁钢生活小区2、4号基坑降水工程为例,针对傍河深基坑具有靠近补给源及含水层厚度大且渗透性强等特点,从降水方案选取、降水设计、降水井施工、对周边的建筑和地下水影响及采取的措施等几个方面,对傍水深基坑降水技术进行了研究,以期为该区域及类似工程提供借鉴和参考。

  19. Practices of efficient high frequency dewatering screen technology in dry discharge of tailings%高效高频脱水筛在尾矿干排处理中的应用实践

    Institute of Scientific and Technical Information of China (English)

    李永亭; 张云龙

    2016-01-01

    The paper sets forth the feasibility of the application of efficient high frequency dewatering screen in dry discharge of tailings , and it has been successfully applied in one gold mine and obtained a dry tailings pile of which the water content is less than 15%.The paper introduces in detail the technical flowsheet and production index of this processing technology in the gold mine ,comprehensively analyzes the running cost and economic benefits of the dewatering screen .Practices prove that this technology requires low investment and low running cost ,renders high wa-ter recovery and prominent benefits ,and it can recover cyanide to the utmost .%阐述了采用高效高频脱水筛处理尾矿的可行性,并在某金矿的尾矿处理中得到了成功应用,最终可得到含水量小于15%的干堆尾矿.该文详细介绍了高效高频脱水筛处理某金矿尾矿的工艺流程和生产指标,且对其运行成本和经济效益进行了综合分析.实践证明,该尾矿处理工艺节省了投资费用,降低了运行成本,提高了回水率,经济效益显著,并可以最大限度地回收利用尾矿废水中的氰化物.

  20. GC-EAD Response ofAnoplophora chinensis to Volatiles fromMelia azedarach%星天牛成虫对楝挥发性物质的GC-EAD反应

    Institute of Scientific and Technical Information of China (English)

    刘佳敏; 徐华潮

    2014-01-01

    Voltile organic compounds/VOCs fromMelia azedarach were collected by dynamic headspace and determined by TDS/ GC/MS. Response ofAnoplophora chinensis to VOCs was detected by GC-EAD. The result demonstrated that there were 20 types of VOCs fromM. azedarach, including 8 terpenoids(97.71%), 5 aromatics(1.021%), 3 alcohols(0.23%), 1 ketones(0.02%). GC-EAD detection showed that that the antenna ofA. chinensis were sensitive to five compounds. Beta-pinene had the most effective to the insect, and L-alpha-pinene, myrcene, styrene butadiene and myrtenol had litter effect.%采用活体植物动态顶空套袋法与气质联用分析技术,对楝(Melia azedarach)的挥发性化学物质进行分析,并且利用GC-EAD技术测定了星天牛(Anoplophora chinensis)成虫对楝挥发性化学物质的GC-EAD反应,结果表明:楝的挥发性化学物质有20种,其中含有萜烯类化合物(97.71%)8种,烃类化合物(1.021%)5种,醇类化合物(0.23%)3种,酮类化合物(0.02%)1种;星天牛成虫的触角对5种化合物的刺激作用比较敏感,其中对β-蒎烯刺激活性最高,对左旋-α-蒎烯、月桂烯、丁苯、桃金娘烯醇有较轻微的反应。

  1. Dewatering of ashes from mixed fuels. Experiences and results from Tekniska Verken in Linkoeping; Avvattning av aska fraan blandbraenslen. Erfarenheter och resultat fraan Tekniska Verken i Linkoeping

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Ulf; Fredriksson, Anders; Lindahl, Inge [Tekniska Verken i Linkoeping AB (Sweden); Arevius, Anna; Sjoeblom, Rolf [AaF-Energikonsult AB, Stockholm (Sweden)

    2003-12-01

    Unit 3 at Tekniska Verken i Linkoeping (TVL) has a grid type furnace. During the firing season 2000 - 2001, the fuel has been comprising 45 % recovered wood chip, 45 % bark and 10 % recovered plastic material. The outfeed has been wet, and flyash and bottom ash have been mixed in the process. During 1999, about 19,000 tonnes of ash with a water content of about 50 % have been generated. The procedure has implied drawbacks in the form of handling of sludge and disposal of material with a high water content. The purpose of the work carried out has been to provide a basis for design of a handling in which these drawbacks have been eliminated, and which supports other destinations for the bottom ash than disposal. The search for information showed that a number of reactions, in particular hydratisation and recrystallisation, take place when ash is in contact with water. The process is strongly dependent on the chemical composition of the ash. The result is influenced not only by the chemical reactions that occur but also by the order in which they take place. Fly ash is very reactive while bottom ash is relatively inert. The experiments in the laboratory scale showed that bottom ash drained well while fly ash as well as different mixtures of fly ash and bottom ash are relatively impermeable to water. The ageing experiments which were carried out did not indicate any particular alteration in the permeability. Tests on a reduced scale clearly showed that bottom ash drains rapidly without the aid of vacuum and that the field capacity (the relative amount of water which does not drain) is low. Mixtures of bottom ash and fly ash drained more when vacuum was applied. However, such mixtures cured within a few hours and this lead to a substantial decrease in permeability. Tests on a pilot scale were conducted using three different methods of dewatering. The tests on self-percolation showed that most of the drainage water appeared during the first few hours where after the

  2. Um modelo sistêmico de avaliação de softwares para educação a distância como apoio à gestão de EaD A model for assessing software as a support for distance learning

    Directory of Open Access Journals (Sweden)

    Eliane Schlemmer

    2007-03-01

    Full Text Available Este artigo apresenta um modelo para avaliação de softwares que possibilitam os chamados Ambientes Virtuais de Aprendizagem (AVAs, baseado no modelo original proposto por Schlemmer e Fagundes (2001 e Schlemmer (2002. O modelo de avaliação é orientado pelo paradigma da complexidade e por uma concepção interacionista/construtivista/sistêmica de Educação a Distância (EaD. Ele foi aplicado a um caso real de avaliação de AVAs em uma instituição de ensino superior brasileira e considera múltiplas perspectivas (tecnológica, comunicacional, social, pedagógica e de gestão, bem como sua aplicação por equipes interdisciplinares (formadas por usuários, educadores, pedagogos, técnicos e gestores. O modelo oferece suporte a esses atores no processo decisório de escolha de um software que forneça uma plataforma para a EaD.A software evaluation model was presented that makes possible a Virtual Learning Environment (VLE based upon the original concept of Schlemmer & Fagundes (2001 and Schlemmer (2002. It was developed using the complexity paradigm as well an interactive, constructivist and systemic conception of education by distance learning and was then used to evaluate a VLE in a Brazilian university. Consideration was given to the multiple technological, communicational, social, pedagogic and managerial perspectives as well as to the application by an interdisciplinary group including users, educators, technicians and managers. This model offers support for the decision making process of choosing adequate software as a platform for distance learning.

  3. Predicting spread of invasive exotic plants into de-watered reservoirs following dam removal on the Elwha River, Olympic National Park, Washington

    Science.gov (United States)

    Woodward, Andrea; Torgersen, Christian E.; Chenoweth, Joshua; Beirne, Katherine; Acker, Steve

    2011-01-01

    The National Park Service is planning to start the restoration of the Elwha River ecosystem in Olympic National Park by removing two high head dams beginning in 2011. The potential for dispersal of exotic plants into dewatered reservoirs following dam removal, which would inhibit restoration of native vegetation, is of great concern. We focused on predicting long-distance dispersal of invasive exotic plants rather than diffusive spread because local sources of invasive species have been surveyed. We included the long-distance dispersal vectors: wind, water, birds, beavers, ungulates, and users of roads and trails. Using information about the current distribution of invasive species from two surveys, various geographic information system techniques and models, and statistical methods, we identified high-priority areas for Park staff to treat prior to dam removal, and areas of the dewatered reservoirs at risk after dam removal.

  4. ESM Calculations for Hydroponic Plant and Fungi Growth Chambers, Biosolids Dewatering Plant System, and Tilapia Growth System--EAC Presentation 2004

    OpenAIRE

    Aydogan, Selen; Blau, Gary; Pekny, Joseph; Reklaitis, Gintaras

    2004-01-01

    In this work, preliminary Equivalent System Mass (ESM) estimations of the Hydroponic Plant and Fungi Growth Chambers, Biosolids Dewatering Plant and Tilapia Growth Systems are presented. ESM may be used to evaluate a system or technology based on its mass, volume, power, cooling and manpower requirements. This ESM analysis focuses on a hypothetical device, instead of the anticipated technology that is system flight proven in mission operations. We have examined the Evolved Mars Base mission, ...

  5. Comparison of digestate from solid anaerobic digesters and dewatered effluent from liquid anaerobic digesters as inocula for solid state anaerobic digestion of yard trimmings.

    Science.gov (United States)

    Xu, Fuqing; Wang, Feng; Lin, Long; Li, Yebo

    2016-01-01

    To select a proper inoculum for the solid state anaerobic digestion (SS-AD) of yard trimmings, digestate from solid anaerobic digesters and dewatered effluent from liquid anaerobic digesters were compared at substrate-to-inoculum (S/I) ratios from 0.2 to 2 (dry basis), and total solids (TS) contents from 20% to 35%. The highest methane yield of around 244L/kg VSfeed was obtained at an S/I ratio of 0.2 and TS content of 20% for both types of inoculum. The highest volumetric methane productivity was obtained with dewatered effluent at an S/I ratio of 0.6 and TS content of 24%. The two types of inoculum were found comparable regarding methane yields and volumetric methane productivities at each S/I ratio, while using dewatered effluent as inoculum reduced the startup time. An S/I ratio of 1 was determined to be a critical level and should be set as the upper limit for mesophilic SS-AD of yard trimmings.

  6. 工程降水中人工回灌综合技术%Integrated technique of artificial recharge in engineering dewatering

    Institute of Scientific and Technical Information of China (English)

    冶雪艳; 耿冬青; 杜新强; 王福刚; 曹东军

    2011-01-01

    建筑工程降水往往伴生水资源浪费和地面变形等环境问题,人工回灌是解决这些问题的有效手段之一.影响工程降水中人工回灌的条件有回灌场地水文地质条件、回灌水源水质和水量及回灌方案的经济可行性等因素.就工程降水中出现的问题,提出资源补充型回灌和应力稳定型回灌方法,并给出了适用条件;根据工程降水水质特点及现有的地下水人工回灌相关水质标准,提出工程降水回灌水质的控制指标主要为悬浮物、浊度、一般污染性指标、微生物指标及重金属等.针对目前人工回灌在工程中存在的可回灌性低的问题,进行了影响入渗速率因素研究,为今后开展促渗关键技术提供理论支持.%The waste of water resources, ground deformation and other environmental issues are often associated with construction industry dewatering. Artificial recharge is an effective mean to solve these problems. Influential factors of artificial recharge in engineering dewatering are hydrogeological conditions of recharge site, water quality and quantity of recharge and the economic feasibility of recharge program. For the problems in the engineering dewatering, the authors propose two kinds of recharge methods including water resources supplement recharge and stress stable recharge, and propose the applicable conditions. According to the features of construction dewatering and the artificial recharge standards of native grounduater, it was suggested that the water quality control indicators of engineering dewatering are suspended solids, turbidity, general pollution indexes, microbial indexes and heavy metals. Aiming at the problem of low recharge in artificial recharge of construction, the factors that affect the infiltration rate is studied to give theoretical support of the key technology of promotion infiltration in future.

  7. An Experimental Study on Axial Temperature Distribution of Combustion of Dewatered Poultry Sludge in Fluidized bed combustor

    Directory of Open Access Journals (Sweden)

    Abbas A.H.

    2016-01-01

    Full Text Available A laboratory scale bubbling fluidized bed combustor was designed and fabricated to study the combustion of dewatered poultry sludge at different operational parameters. This paper present a study on the influence of equivalent ratio, secondary to primary air ratio and the fuel feed rate on the temperature distribution along the combustor. The equivalent ratio has been changed between 0.8 to 1.4% under poultry sludge feed rate of 10 kg/h and from 0.8 to 1 under poultry sludge feed rate of 15 kg/h. The secondary to primary air ratio was varied from 0.1 to 0.5 at 0.65 m injection height and 1.25 equivalent ratio. The results showed that these factors had a significant influence on the combustion characteristics of poultry sludge. The temperature distribution along the combustor was found to be strongly dependent on the fuel feed rate and the equivalent ratio and it increased when these two factors increased. However, the secondary air ratio increased the temperature in the lower region of the combustor while no significant effect was observed at the upper region of the combustor. The results suggested that the poultry sludge can be used as a fuel with high thermal combustor efficiency.

  8. Bacterial polymer production using pre-treated sludge as raw material and its flocculation and dewatering potential.

    Science.gov (United States)

    More, T T; Yan, S; Hoang, N V; Tyagi, R D; Surampalli, R Y

    2012-10-01

    Sterilization, alkaline-thermal and acid-thermal treatments were applied to different sludge solids concentrations (17.0; 22.4; 29.8; 37.3; 44.8 g/L, respectively) and the pre-treated sludge was used as raw material for Serratia sp.1 to produce extracellular polymeric substances (EPS). After 72 h of fermentation, total EPS of 2.3 and 3.4 g/L were produced in sterilized and alkaline-thermal treated sludge as compared to that of 1.5 g/L in acid-thermal treated sludge. Lower EPS were produced at relatively higher solids concentrations (37.3; 44.8 g/L). Broth, crude forms of capsular and slime EPS were extracted from fermented broths and used as conditioning agents by combining with 150 mg of Ca(2+)/L of kaolin suspensions. Maximum flocculation activity of 79.1% and increased dewatering by 52.2% was achieved using broth and crude capsular EPS, respectively. The results demonstrated that EPS having high flocculating capability could be produced using wastewater sludge as sole raw material.

  9. InSAR analysis of aquifer-system response to 20 years of mine-dewatering in the Carlin gold trend, north-central Nevada

    Science.gov (United States)

    Bell, J. W.; Katzenstein, K.

    2012-12-01

    The Carlin trend in north-central Nevada has the second largest gold resources in the world, most of it produced from large open-pit mines. Heavy groundwater dewatering is required at the mines to lower water levels below the depth of mining which can exceed 400-500 m. The resulting water level declines have produced surface deformation (subsidence) that can be detected and modeled with InSAR to characterize the aquifer-system response and to estimate hydraulic parameters in order to test and refine groundwater models. In a series of studies we examined the effects of dewatering at mines operated by Newmont Mining Corporation and Barrick Gold of North America near Battle Mountain and Carlin, Nevada. The Lone Tree mine operated a large-scale dewatering program between 1992-2006 using deep bedrock wells that pumped between 64-92 hm3/yr (52,000-75,000 acre-ft/yr) and lowered bedrock water levels more than 120 m. InSAR analysis of ERS and Envisat data for the 1992-2000 and 2004-2010 periods showed that as much as 50 cm of aquifer-system compaction occurred in bedrock and in alluvial basin deposits with subsidence rates ranging between 3-6 cm/yr. Since dewatering ended in late 2006 and water levels began rising, only 7 cm of aquifer-system recovery (uplift) has occurred as of 2010 suggesting that most of the aquifer-system compaction was likely inelastic, apparently in the pumped fractured bedrock. The InSAR subsidence data differ significantly from the pre-pumping groundwater model which predicted 2.5 m of subsidence for the 1992-2000 period. The results yield bulk storage coefficients in the range of 7 x 10-3 to 5.6 x 10-5 with a most frequent value of 1.0 x 10-3 (Baffoe-Twum, 2007), InSAR-derived hydraulic values that can provide better constraints on specific storage estimates in future groundwater models. The Betze-Post mine has been dewatering continually since late 1989 with maximum pumping rates of greater than 140 hm3/yr (110,000 acre-ft/yr) in the early and

  10. Experiência de EAD na formação de gestores educacionais: educação visual e construção de narrativas/Experience of on-line education in the educational management training: visual education and construction of narratives

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Albuquerque Miranda

    2009-06-01

    Full Text Available O objetivo deste artigo é apresentar a experiência de EAD da disciplina ‘Escola, Gestão e Cultura’ no ‘Curso de Especialização em Gestão Educacional’ (CEGE oferecido pela Faculdade de Educação da Unicamp. A proposta de EAD desta disciplina é trabalhar com educação visual e produção de narrativas de professores. Utilizamos as ferramentas de comunicação do ambiente virtual TelEduc para implementar uma dinâmica pedagógica assincrônica de trabalho docente. Esta dinâmica se apresenta como alternativa à lógica de concomitância entre parte presencial e parte em EAD do CEGE. Os resultados apresentados permitem-nos refletir sobre as potencialidades pedagógicas das tecnologias de informação e comunicação e alguns posicionamentos em relação ao trabalho docente em EAD. This article have objective of the present the experience of on-line education of the discipline ‘Escola, Gestão e Cultura’ in the ‘Curso de Especialização em Gestão educacional’ (CEGE offered by the Faculty of Education at Unicamp. The proposed on-line education of this discipline is to work with visual education and production of narratives of teachers. We use the tools of communication in virtual environment TelEduc to implement a pedagogical dynamic asynchronous at teaching work. This dynamic presents itself as an alternative to the logic of concomitance between the presencial part of the CEGE the of the online education part. The results presented allow us to reflect on the pedagogical potential of information and communication technologies and take some positions about to teaching work in the on-line education.

  11. DEWATERING TREATMENT SCALE-UP TESTING RESULTS OF HANFORD TANK WASTES

    Energy Technology Data Exchange (ETDEWEB)

    TEDESCHI AR

    2008-01-23

    This report documents CH2M HILL Hanford Group Inc. (CH2M HILL) 2007 dryer testing results in Richland, WA at the AMEC Nuclear Ltd., GeoMelt Division (AMEC) Horn Rapids Test Site. It provides a discussion of scope and results to qualify the dryer system as a viable unit-operation in the continuing evaluation of the bulk vitrification process. A 10,000 liter (L) dryer/mixer was tested for supplemental treatment of Hanford tank low-activity wastes, drying and mixing a simulated non-radioactive salt solution with glass forming minerals. Testing validated the full scale equipment for producing dried product similar to smaller scale tests, and qualified the dryer system for a subsequent integrated dryer/vitrification test using the same simulant and glass formers. The dryer system is planned for installation at the Hanford tank farms to dry/mix radioactive waste for final treatment evaluation of the supplemental bulk vitrification process.

  12. Characteristics of the microwave pyrolysis and microwave CO2-assisted gasification of dewatered sewage sludge.

    Science.gov (United States)

    Chun, Young Nam; Jeong, Byeo Ri

    2017-07-28

    Microwave drying-pyrolysis or drying-gasification characteristics were examined to convert sewage sludge into energy and resources. The gasification was carried out with carbon dioxide as a gasifying agent. The examination results were compared with those of the conventional heating-type electric furnace to compare both product characteristics. Through the pyrolysis or gasification, gas, tar, and char were generated as products. The produced gas was the largest component of each process, followed by the sludge char and the tar. During the pyrolysis process, the main components of the produced gas were hydrogen and carbon monoxide, with a small amount of hydrocarbons such as methane and ethylene. In the gasification process, however, the amount of carbon monoxide was greater than the amount of hydrogen. In microwave gasification, a large amount of heavy tar was produced. The largest amount of benzene in light tar was generated from the pyrolysis or gasification. Ammonia and hydrogen cyanide, which are precursors of NOx, were also generated. In the microwave heating method, the sludge char produced by pyrolysis and gasification had pores in the mesopore range. This could be explained that the gas obtained from the microwave pyrolysis or gasification of the wet sewage sludge can be used as an alternative fuel, but the tar and NOx precursors in the produced gas should be treated. Sludge char can be used as a biomass solid fuel or as a tar removal adsorbent if necessary.

  13. Direct molecular diffusion and micro-mixing for rapid dewatering of LiBr solution

    Energy Technology Data Exchange (ETDEWEB)

    Bigham, S; Isfahani, RN; Moghaddam, S

    2014-03-01

    A slow molecular diffusion rate often limits the desorption process of an absorbate molecule from a liquid absorbent. To enhance the desorption rate, the absorbent is often boiled to increase the liquid vapor interfacial area. However, the growth of bubbles generated during the nucleate boiling process still remains mass-diffusion limited. Here, it is shown that a desorption rate higher than that of boiling can be achieved, if the vapor absorbent interface is continuously replenished with the absorbate-rich solution to limit the concentration boundary layer growth. The study is conducted in a LiBr-water-solution, in which the water molecules' diffusion rate is quite slow. The manipulation of the vapor solution interface concentration distribution is enabled by the mechanical confinement of the solution flow within microchannels, using a hydrophobic vapor-venting membrane and the implementation of microstructures on the flow channel's bottom wall. The microstructures stretch and fold the laminar streamlines within the solution film and produce vortices. The vortices continuously replace the concentrated solution at the vapor solution interface with the water-rich solution brought from the bottom and middle of the flow channel. The physics of the process is described using a combination of experimental and numerical studies. Published by Elsevier Ltd.

  14. Application of Plate-and-Frame Filter Press for Sludge Dewatering in Water Treatment Plant%板框压滤机在自来水厂污泥脱水中的应用

    Institute of Scientific and Technical Information of China (English)

    袁华为

    2016-01-01

    This article described the water treatment plant sludge treatment situation,analyzed water treatment plant sludge dewatering methods and characteristics. Based on actual cases,actionable recommendations were put forward on sludge dewatering of water treatment plant,these conclusions on sludge dewatering problems may be meaningful to similar water treatment plants.%该文通过介绍某自来水厂的污泥处理状况,分析了利用各种脱水方式进行自来水污泥脱水的优缺点,根据实际案例,对小型自来水厂污泥处理设备设施提出了可操作的方案,为相似水厂在污泥脱水处理问题上提供参考。

  15. Application of ultra-flocculation for improving fine coal concentrate dewatering

    Energy Technology Data Exchange (ETDEWEB)

    N.N. Rulyov; B.Y. Korolyov; N.M. Kovalchuk [Ukrainian National Academy of Sciences, Kiev (Ukraine). Institute of Biocolloid Chemistry

    2006-01-15

    The possibility of significant improvements in vacuum filtration of fine coal suspensions through the application of ultra-flocculation was studied. It was shown theoretically that even when present in quantities of a few percent, the ultrafine particles (<10 microns) highly contributed to the hydraulic resistance of the filter cake. The experiments showed that short-term hydrodynamic treatment of the coal suspension at relatively high medium velocity gradients (750 s{sup -1}) performed immediately upon the introduction of the flocculant resulted in significant improvements in the filtration process due to the effect of specifically binding the finest particles. This treatment decreased the hydraulic resistance of the cake on the screen vacuum filter by roughly 1.6 times, decreased the solids content in the filtrate by 4 times and decreased the flocculant consumption by 2 times.

  16. The use of acoustic fields as a filtration and dewatering aid

    Science.gov (United States)

    Smythe; Wakeman

    2000-03-01

    An experimental rig has been developed to study the effects of electric and acoustic field combinations on the filtration rate of titanium dioxide suspensions. Ultrasound energy is applied tangentially to the filter medium. Electric field strengths, suspension characteristics and process parameters can all be varied independently. Results from an experimental programme demonstrate that the use of ultrasound across the cake surface can decrease the specific cake flow resistance and increase the filtration rates of low-concentration rutile suspensions (0.1% v/v). Changes in the conductivity induced by ultrasonic irradiation affect the suspension such that the application of an electrical field is enhanced, giving an equivalent electric field strength higher than that applied.

  17. Results for the Brine Evaporation Bag (BEB) Brine Processing Test

    Science.gov (United States)

    Delzeit, Lance; Flynn, Michael; Fisher, John; Shaw, Hali; Kawashima, Brian; Beeler, David; Howard, Kevin

    2015-01-01

    The recent Brine Processing Test compared the NASA Forward Osmosis Brine Dewatering (FOBD), Paragon Ionomer Water Processor (IWP), UMPQUA Ultrasonic Brine Dewatering System (UBDS), and the NASA Brine Evaporation Bag (BEB). This paper reports the results of the BEB. The BEB was operated at 70 deg C and a base pressure of 12 torr. The BEB was operated in a batch mode, and processed 0.4L of brine per batch. Two different brine feeds were tested, a chromic acid-urine brine and a chromic acid-urine-hygiene mix brine. The chromic acid-urine brine, known as the ISS Alternate Pretreatment Brine, had an average processing rate of 95 mL/hr with a specific power of 5kWhr/L. The complete results of these tests will be reported within this paper.

  18. Dewatering and removal of metals from urban anaerobically digested sludge by Fenton's oxidation.

    Science.gov (United States)

    Fontmorin, J-M; Sillanpää, Mika

    2017-02-01

    In this study, the relevance of Fenton's reaction for the treatment of urban anaerobically digested sludge was investigated. In a first part, the impact of the oxidation process on the improvement of the sludge dewaterability was studied. In a second part, the removal of heavy metals from the sludge was examined. Fenton's reaction was carried out with increasing concentrations of Fe(2+) and H2O2 in 1:10 and 1:1 ratios. Dewaterability of the raw sludge was highly improved: the addition of 36 mM Fe(2+) and 360 mM H2O2 led to specific cake resistance (SCR) and capillary suction time (CST) reductions of 99.8% and 98.8%, respectively. Indeed, under these conditions, SCR and CST of respectively 1.04 × 10(11) m kg(-1) and 18.5 ± 0.2 s were measured, and the treated sludge could be considered as having 'good dewaterability'. A significant impact was also observed on the removal of heavy metals from the sludge. After 1-h oxidation, Cd, Cr, Cu, Pb and Zn could be removed by 81.1 ± 0.1%, 25.1 ± 0.1%, 87.2 ± 1.1%, 77.3 ± 4.8% and 99.6 ± 0.3%, respectively. These results were consistent with the heavy metals' fractions in the sludge. It could be concluded that the addition of Fe(2+) and H2O2 in a 1:10 ratio was more effective than in a 1:1 ratio. The results were consistent with the extracellular polymeric substance (EPS) contents in raw and treated sludge, since loosely bound EPS decreased significantly after the treatment.

  19. O estágio supervisionado do curso de pedagogia EAD/UFPI: apresentação da perspectiva legal e de funcionamento

    Directory of Open Access Journals (Sweden)

    Lívia Fernanda Nery da Silva

    2017-01-01

    Full Text Available This research analyzes the supervisioned internship in Distance Education Pedagogy students at UFPI. To back it up, search the theoretical contribution of authors like Litwin (2001 and Pimenta (2004. As methodological resource, we used documental analysis, taking as source the Pedagogical Political Project of the course, Decree 5.622/05 and 6.303/07, which regulates Article 80 of the LDB, as well as the reports posted on the digital classroom by the students of Education from Simplicio Mendes City, in the years 2012 and 2013. After the analysis of the legislation, one notices that the supervised training distance education raises questions, namely: How effective is the supervised internship distance education? What are the internships scheduled for the pedagogy course DE/UFPI? Based on the initial findings, it was perceives that the effectiveness of the insternship occurred with the teaching practice, which is strengthened with the aid of technological resources. However, the mere transposition of the rules of the classroom stage, disregarding the specifics of distance education, can be detrimental to teacher formation process in the distance mode, so it is understood that the supervised internship training on distance education requires the creation of standards that address the specificities of the distance education model.

  20. Addition of polyaluminiumchloride (PACl) to waste activated sludge to mitigate the negative effects of its sticky phase in dewatering-drying operations.

    Science.gov (United States)

    Peeters, Bart; Dewil, Raf; Vernimmen, Luc; Van den Bogaert, Benno; Smets, Ilse Y

    2013-07-01

    This paper presents a new application of polyaluminiumchloride (PACl) as a conditioner for waste activated sludge prior its dewatering and drying. It is demonstrated at lab scale with a shear test-based protocol that a dose ranging from 50 to 150 g PACl/kg MLSS (mixed liquor suspended solids) mitigates the stickiness of partially dried sludge with a dry solids content between 25 and 60 %DS (dry solids). E.g., at a solids dryness of 46% DS the shear stress required to have the pre-consolidated sludge slip over a steel surface is reduced with 35%. The salient feature of PACl is further supported by torque data from a full scale decanter centrifuge used to dewater waste sludge. The maximal torque developed by the screw conveyor inside the decanter centrifuge is substantially reduced with 20% in the case the sludge feed is conditioned with PACl. The beneficial effect of waste sludge conditioning with PACl is proposed to be the result of the bound water associated with the aluminium polymers in PACl solutions which act as a type of lubrication for the intrinsically sticky sludge solids during the course of drying. It can be anticipated that PACl addition to waste sludge will become a technically feasible and very effective method to avoid worldwide fouling problems in direct sludge dryers, and to reduce torque issues in indirect sludge dryers as well as in sludge decanter centrifuges.

  1. 南美重质高含盐原油脱盐脱水技术分析%South America’s High Density High Salt Crude Oil Desalting and Dewatering Technical Analysis

    Institute of Scientific and Technical Information of China (English)

    陈东魁; 冯纯妍; 于学战; 杨光

    2015-01-01

    South America heavy crude oil such as Merry and Boscan has the characteristics of high density high salt content .These reasons caused crude oil desalting and dewatering is very difficult, will bring device corrosion risk, and affect the normal operation. By adopting the one vertica-two horizontal electric desalting tank combination process,using the special heavy-oil efficient demulsification desalter,and improving the heat transfer process measures to optimize the operation of the electric desalting conditions,can make the South American crude oil desalting rate of more than 90%, water can be reduced to less than 0.1%. Good results have been achieved.%南美马瑞油、波斯坎油等重质原油具有高密度高含盐量的特点,给原油脱盐脱水带来很大难度,进而对装置造成腐蚀风险并影响正常运行。通过采取一级立式-两级卧式电脱盐罐组合工艺,使用专用的重油高效破乳脱盐剂,以及优化电脱盐运行条件等措施,可将南美重质高含盐原油脱盐率达到90%以上,脱后含水可降至0.1%以内,取得了较好的效果。

  2. 酸碱联合调节剩余污泥对有机质的释放和脱水性能的影响%Effect of co-adjusting excess sludge with acid and alkaline on release of organic matter and dewatering performance

    Institute of Scientific and Technical Information of China (English)

    苑宏英; 牛四芳; 宋建阳; 祁丽; 汤韬

    2013-01-01

    为了研究酸碱联合调节剩余污泥水解酸化过程中溶解性蛋白质(SPN)和溶解性碳水化合物(SPS)的释放规律以及对脱水性能的影响,采用3个反应器,其中,1 #为先酸(pH3.0)后碱(pH 10.0)、3 #为先碱(pH 10.0)后酸(pH 3.0)的两段控制方式(每段8d),同时以2# pH不调作为对比实验.结果表明,3个反应器中SPN和SPS的释放情况是调节为碱性>酸性>空白,在相同的控制阶段,SPN的释放量明显高于SPS的释放量;SPN和SPS的最大释放量出现在1#的碱性阶段(后8d),SPN在碱性阶段的第2天达到最大释放量(883.618 mg/L),SPS在碱性阶段的第8天达到最大释放量(165.922 mg/L).1#在实验的整个过程中比阻值较低,说明先酸后碱调节方式更利于污泥脱水;在调节为碱性第4天时污泥比阻(SRF)达到最小值(0.342×1013m/kg),处于中难度脱水范围内.与2#相比,3#中的SRF虽稍有改善,但始终处于难脱水范围内.%During the hydrolysis and acidification of co-adjusting excess sludge with acid and alkaline,it was studied that the release law of soluble protein (SPN) and soluble carbohydrates (SPS) and effect on dewatering performance by taking the followed two-step controlling means,which were 1 # from acidity (pH 3.0) to alkalinity(pH 10.0),3# from alkalinity(pH 10.0) to acidity(pH 3.0),each step 8 days,and 2# pH unadjusted as control test of three reactors,respectively.The results show that the release situation of SPN and SPS is alkalinity > acidity > blank and the release quatity of SPN is greater than SPS apparently at the same control stage of three reactors; both of the maximum release quatity of SPN and SPS appear on alkalinity control stage(8 days after) of 1# with the max release quatity of SPN appearing on the second day(883.618 mg/L) and SPS appearing on the 8th day(165.922 mg/L) respectively.SRF is lower in the whole process of experiment of 1#,indicating that from acidity to alkalinity is more conducive to

  3. Microfluidic Device for Automated High-Throughput Protein Crystallization Screening by Osmotic Dewatering%基于渗透脱水的自动化蛋白质结晶高通量筛选芯片

    Institute of Scientific and Technical Information of China (English)

    罗娅慧; 李刚; 陈强; 赵建龙

    2012-01-01

    构建了一种基于渗透脱水模式的自动进样微流控结晶芯片.该芯片通过真空预脱气将包含蛋白质和结晶剂的液滴自动分配至结晶微腔阵列中,然后利用集成的一排包含不同浓度盐溶液的透析管道,通过渗透脱水方式经一层聚二甲基硅氧烷(PDMS)膜实现液滴的逐渐浓缩,使之趋于过饱和状态,进而形成结晶.此芯片可一次筛选较宽范围的过饱和状态,实现蛋白质结晶的快速优化.利用模式蛋白溶菌酶的结晶实验验证了该芯片的性能.%A self-dispensing and osmosis-based microfluidic crystallization device was reported. This device automatically dispenses droplets containing protein and precipitant into an array of crystallization chambers by pre-degassing, and then gradually concentrates these droplets at different rates by osmotic dewatering through a polydimethylsiboxane(PDMS) membrane using a row of integrated dialysis channels filled with different concentration of salt solution. This concentration process drives the protein/precipitant mixture into supersaturated , thus tending toward the crystallization state. This device allows for screening a wide range of supersatura-tion in one trial for rapid optimization of protein crystallization. The feasibility of this crystallization device is demonstrated using the model proteins of lysozyme.

  4. Dewatering and Volume Reduction of Heavy Metal-contaminated Sediments in Lake and Reservoir Using Geotextile Tubes%重金属污染底泥的土工管袋高效脱水减容研究

    Institute of Scientific and Technical Information of China (English)

    张景辉; 刘朝辉; 西伟力; 王旭东; 董晶; 毕涛; 王文茜

    2011-01-01

    基于环保疏浚过程中湖库重金属污染底泥的特点,研究了土工管袋处理技术脱水减容重金属污泥的效果.通过试验筛选和优化,获得了土工管袋脱水效果最佳的重金属螯合钝化调质剂ECO-DEMETAL及其最佳添加量.通过容量为25 L的小袋脱水试验研究发现,脱水7d后污泥含固率由5%提高到70%左右,污泥脱水后重金属浸出毒性的检测结果远优于《生活垃圾填埋场污染控制标准》( GB 16889-2008)的指标要求.通过土工管袋1:1现场扩大试验,获得了容量为1 000 m3的大型土工管袋污泥脱水工程应用经验,脱水效果非常理想,含固率>50%,重金属钝化效果也完全满足填埋造岛资源化处置的环保要求.%Based on characters of heavy metal-contaminated sediments in lake and reservoir during environment-friendly dredging, the dewatering and volume reduction of heavy metal-contaminated sediments with geotextile tubes were studied. A conditioner, known as ECO-DEMETAL for heavy metal che-lation and passivation with the optimal dewatering efficiency of geotextile tubes as well as its optimal dosage were obtained by selection and optimization experiments. The dewatering result of 25 L geotextile tube show that the solid content of sludge is increased from 5% to 70% within 7 days, and the toxicity characteristic leaching procedure ( TCLP) result meets to the requirement of the Standard for Pollution Control on the Landfill Site for Domestic Waste ( GB 16889 -2008). Dewatering experiments in pilot scale were carried out for verification of dewatering performance of 1 000 m geotextile tube. The pilot results show that the dewatering efficiency is ideal, the solid content of sludge is more than 50% , and the passivation effect of heavy metals also meets the environmental requirement in landfdl resource disposal for island creation.

  5. Experimental study on dewatering and consolidation of sludge from environment dredging by using geotextile tubes%土工管袋用于环保疏浚淤泥脱水固结的试验研究

    Institute of Scientific and Technical Information of China (English)

    王琦; 仰建国; 范文雪

    2014-01-01

    The dewatering and consolidation experiment of sludge from environmental is carried out by using small-sized geo-textile tubes. The influences of different structural characteristics of geotextile tubes such as weaving method,weaving structure and aperture,and dosages of dewatering agent on its dewatering and consolidation effects are studied. The results show that the dewatering and consolidation effect of the woven twill geotextile tube with 0.5 mm aperture is better. And the effect of cationic polyacrylamide (CPAM) in the dosage of 0.6~1.0 g/kg is also better. But the best dosage must be adjusted according to the different conditions in the practical projects.%利用小型土工管袋进行环保疏浚淤泥脱水固结试验,研究土工管袋的不同结构特征(织造方式、织造结构、等效孔径)和脱水药剂用量对环保疏浚淤泥脱水固结的影响。试验结果表明:脱水药剂阳离子聚丙烯酰胺(CPAM)在0.6~1.0 g/kg投加量下配合0.5 mm等效孔径机织斜纹土工管袋组合,在疏浚淤泥脱水固结方面表现较好,但脱水药剂具体最佳用量需在实际工程中根据不同工况做适当调整。

  6. 污泥脱水、干化、焚烧一体化控制系统%An Integrated ControI System for SIudge Dewatering,Drying and Incineration

    Institute of Scientific and Technical Information of China (English)

    张明锐; 林显琦; 王少波

    2014-01-01

    根据污泥脱水、干化、焚烧一体化技术,分析系统的构成,设计自动控制系统。采用PROFIBUS-DP网络实现上位机与PLC之间的连接。根据工艺流程制定系统运行策略,融入智能算法,提高污泥处理的可靠性和效率。应用InTouch 10.1组态软件开发上位机软件,绘制组态画面,实时监控整个系统的运行。针对薄弱环节增加报警参量,设置自动、手动两种运行模式,实现正常情况下工艺流程的自动化和故障检修时人工的灵活操作,提高了控制系统的智能度。%Based on the technology integrating sludge dewatering,drying and incineration,this paper analyzes the system composition and designs an automatic control system.The upper computer and PLC is connected via PROFIBUS-DP network.Based on the technological process,the system operation strategy with intelligent algorithm is drawn up to improve the reliability and efficiency of sludge treatment.Configuration software InTouch 10.1 is used to develop upper computer software and draw configuration screens to monitor the operation of entire system on a real-time basis.Through increase of alarm parameters for weak links and setup of automatic and manual operational modes,we can realize automation under normal technological process as well as flexible operation during fault correction,thus raising the intelligence of the control system.

  7. Results of the GCMS Effluent Gas Analysis for the Brine Processing Test

    Science.gov (United States)

    Delzeit, Lance; Lee, Jeffrey; Flynn, Michael; Fisher, John; Shaw, Hali; Kawashima, Brian; Beeler, David; Harris, Linden

    2015-01-01

    The effluent gas for the Paragon Ionomer Water Processor (IWP), UMPQUA Ultrasonic Brine Dewatering System (UBDS), and the NASA Brine Evaporation Bag (BEB) were analyzed using Headspace GCMS Analysis in the recent AES FY14 Brine Processing Test. The results from the analysis describe the number and general chemical species of the chemicals produced. Comparisons were also made between the different chromatograms for each system, and an explanation of the differences in the results is reported.

  8. DO对硫杆菌污泥调理系统脱水效能的影响%Effect of DO on Dewatering Efficiency of Sludge Conditioning System with Thiobacillus Thiooxidans

    Institute of Scientific and Technical Information of China (English)

    刘杰; 周健; 陈浬; 李彦澄; 杨志

    2013-01-01

    The existing sludge conditioning technology has low improvement efficiency of sludge dewatering and cannot meet the requirements of moisture content in sludge disposal.The conditioning of excess sludge with Thiobacillus Thiooxidans was proposed.The effect of DO on the dewatering efficiency of the excess sludge conditioning system with Thiobacillus Thiooxidans was investigated.When DO was 6 mg/L,the moisture content of dewatered sludge decreased from 75.5% to 63.6%.The contents of protein,humic substance,polysaccharides in EPS decreased to 3.67 mg/gVSS,3.15 mg/gVSS and 16.17mg/gVSS respectively.The bound water decreased from 2.63 g/gDS to 1.48 g/gDS.The Zeta potential decreased from-14.9 mV to 0.27 mV.The average particle size of dewatered sludge increased from 20.19 μm to 34.51 μm.The conditioning system of excess sludge with Thiobacillus Thiooxidans had significant improvements on sludge dewatering performance.%针对现有污泥调理技术对污泥脱水性能改善效能低,难以达到现行污泥处置标准对含水率要求的问题,提出了剩余污泥氧化硫硫杆菌生物调理技术,考察了DO对剩余污泥硫杆菌生物调理系统深度脱水效能的影响.在DO为6 mg/L条件下,氧化硫硫杆菌生物调理系统调理污泥脱水后的含水率由75.5%降至63.6%;EPS中蛋白质、腐殖质、多糖分别减少为3.67、3.15、16.17mg/gVSS,污泥结合水含量从2.63 g/gDS降低至1.48 g/gDS;污泥Zeta电位从-14.9 mV降低至0.27 mV,污泥絮体颗粒平均粒径由20.19 μm增大到34.51 μm,硫杆菌生物调理系统对污泥脱水性能改善显著.

  9. Influence of the reactant carbon-hydrogen-oxygen composition on the key products of the direct gasification of dewatered sewage sludge in supercritical water.

    Science.gov (United States)

    Gong, Miao; Zhu, Wei; Fan, Yujie; Zhang, Huiwen; Su, Ying

    2016-05-01

    The supercritical water gasification of ten different types of dewatered sewage sludges was investigated to understand the relationship between sludge properties and gasification products. Experiments were performed in a high-pressure autoclave at 400°C for 60 min. Results showed that gasification of sewage sludge in supercritical water consists mainly of a gasification reaction, a carbonization reaction and a persistent organic pollutants synthesis reaction. Changes in the reactant C/H/O composition have significant effects on the key gasification products. Total gas production increased with increasing C/H2O of the reactant. The char/coke content increased with increasing C/H ratio of the reactant. A decrease in the C/O ratio of the reactant led to a reduction in polycyclic aromatic hydrocarbon formation. This means that we can adjust the reactant C/H/O composition by adding carbon-, hydrogen-, and oxygen-containing substances such as coal, algae and H2O2 to optimize hydrogen production and to inhibit an undesired by-product formation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Characterization of morphology and component of struvite pellets crystallized from sludge dewatering liquor: Effects of total suspended solid and phosphate concentrations.

    Science.gov (United States)

    Ping, Qian; Li, Yongmei; Wu, Xinghai; Yang, Lu; Wang, Lin

    2016-06-05

    A lab-scale struvite pellet crystallization system was used to study phosphorus (P) removal and recovery from sludge dewatering liquor (SDL). Influences of total suspended solids (TSS) and phosphate concentrations on P removal as well as the size, morphology, purity, and components of struvite pellets were investigated. The increase in TSS concentration resulted in not only the decreases in phosphate removal efficiency and struvite purity but also the irregular pellet morphology and broken struvite crystals. Increasing inlet PO4-P concentration enhanced PO4-P removal, average struvite pellet diameter, purity and crystal volume growth rate. Amorphous calcium phosphate (ACP), calcite, brucite and magnesium phosphate were formed as co-precipitates with struvite. However, species and quantity of co-precipitates could be variable. More calcium precipitates were easily formed at lower PO4-P concentration (48mg/L), while brucite was the main co-precipitate at higher PO4-P concentration (151mg/L). Organic compounds were involved in struvite pellets along with suspended solids during the formation of struvite. Higher TSS concentration resulted in both more species and higher contents of organic compounds in struvite pellets. Therefore, it is essential to remove suspended solids in advance so as to obtain high P-removal and harvest high-quality struvite pellets. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. 热力隧道在非降水施工中的力学特性监测%Analysis of mechanical behavior monitoring test of thermal tunnel with non-dewatering construction

    Institute of Scientific and Technical Information of China (English)

    康富中; 贺少辉; 李承辉; 陈新栋; 张耘获

    2011-01-01

    More and more urban thermal water supply project comes from the deep depth excavation gradually, rather than the cut and cover shallow buries. The in-situ monitoring tests of Beijing two typical geology thermal tunnels are carried out. Then this paper analyzed the internal stress charactcristics of supported structure lining, the surrounding rock mechanics characters, the hydraulic characteristics, and the ground surface settlement influence in sand-pebbles geological and silty-clay geological conditions with non-dewatering construction process. The research monitoring results show that the surrounding rock pressure distribution is different under various geological conditions, but the water pressure distribution is similar under different geological conditions, and the lining steel internal forces distribution is also different. The lining stress situation in the sand-pebbles geological condition is preferable to that in the silty clay soil condition. Tunnel excavation has less impact on the ground surface settlement. The research results can be applied to small section urban tunnels for thermal supply,water supply and gas supply.%城市热力供水工程逐渐由近地层明挖向深地层暗挖转移,通过对北京市两个典型地质热力隧道的现场原位的监测,分析浅埋暗挖热力隧道在非降水施工过程中对于砂卵石地质和粉质黏土地质条件下的初支结构内力、围岩性状、水文特征的变化及对地层的影响.试验监测结果表明,隧道围岩的土压力分布不同,水压力分布相同,初衬钢筋内力分布不同,砂卵石地质务件下的隧道初衬受力情况较好,隧道开挖对地表沉降影响较小,研究结果可在开挖城市供热、供水及供气等小断面隧道时参考.

  12. Start up and maintenance of partial nitrification-denitrification of high strength ammonia sludge dewatering water%高氨氮污泥脱水液短程硝化反硝化的启动及稳定

    Institute of Scientific and Technical Information of China (English)

    张亮; 王淑莹; 张树军; 吴程程; 甘一萍; 孟春霖; 彭永臻

    2012-01-01

    High strength ammonia sludge dewatering water was treated by a A/O-CSTR process.The ammonia content was about 350 mg/L.The carbon source for denitrification was deficient due to the ratio of C/N was below 1.0.Ammonia of reject water was nitrified in A/O reactor and then reduced to nitrogen gas by denitrifiers in CSTR,with using primary sludge as additional carbon source.The start-up of partial nitrification was investigated.The effects of the effluent recycle on partial nitrification and nitrogen removal efficiency were also studied.The results shows that the system has a good performance in total nitrogen removal.The nitrite accumulate ratio was improved and maintained above 90%.The primary sludge were successful utilized as the carbon source for stable denitrification.The recycle of CSTR effluent benefited nitrogen removal efficiency.As the recycle ratio was 200%,total nitrogen removal efficiency was more than 85%.%采用A/O-CSTR工艺处理高氨氮污泥脱水液。进水氨氮浓度浓度约为375 mg/L,C/N比小于1.0,反硝化碳源明显不足。A/O反应器完成短程硝化反应,CSTR定期投加初沉污泥作为碳源进行反硝化。两者联合达到总氮去除的目的。实验研究短程硝化反应的启动过程,以及CSTR出水回流对短程硝化和系统脱氮效果的影响。实验结果表明系统具有良好的硝化反硝化效果。A/O反应器亚硝酸盐积累率迅速提高并稳定在90%以上。CSTR有效利用初沉污泥实现了稳定的反硝化。出水回流有利于提高总氮去除率,在回流比为200%时,系统平均总氮去除率达到85%以上。

  13. 水热及微波处理对我国典型褐煤气化特性的影响%Influence of the Hydrothermal Dewatering and microwave irradiation treatment on the Gasification Characteristics of Typical Chinese Lignite

    Institute of Scientific and Technical Information of China (English)

    王智化; 葛立超; 徐超群

    2016-01-01

    The influences of hydrothermal dewatering (HTD) and microwave irradiation performed at different temperatures on the gasification characteristics of typical lignites with different metamorphic grades in China were investigated in this paper. Results show that the upgrading process significantly decreases the inherent moisture at a maximum degree of 87.31% and oxygen content, and increases calorific value and fixed carbon content, According to the oxygen/carbon ratio parameter, the coal rank increases. The complex changes occurred on coal structure during the HTD process lead to pore size of coal char develop to the microporous region, and the surface area and volume increase at first but then decrease. Due to the development of coal structure and the increment of coal rank, the gasification process of upgraded coal is delayed towards high temperature region, the temperatures when carbon conversion rate reaches 50% increase. From the results of kinetic calculation, activation energy increases after treatment, and the reaction order of mechanistic model is changed. Besides, all the changes caused by HTD are more obvious when the upgraded temperature increased from 250 °C to 300 °C and when the rank of raw brown coal was lower. The upgrading process significantly decreased the inherent moisture content at a maximum degree of 87.31 % in a short time, and increased the calorific value and fixed carbon content. The moisture contents of all upgraded coals were less than 10 wt%. After upgrading, pore distribution extended to the micropore region, the surface area and volume increased, and the average pore size decreased. Based on thermo-gravimetric analysis, the temperature when carbon conversion rate reaches 50% decreased, and the gasification rate increased, indicating the increase of gasification activity. From the results of kinetic calculation,activation energy decreased after treatment, and the reaction order of mechanistic model changed. All the changes caused by

  14. 过氧乙酸破解和化学重絮凝改善活性污泥过滤脱水性能%Enhancement of activated sludge dewatering performance with combined peroxyacetic acid oxiution and chemical re?flocculation with inorganic coagulants

    Institute of Scientific and Technical Information of China (English)

    曹秉帝; 张伟军; 王东升; 段晋明

    2016-01-01

    Extracellular polymeric substances ( EPS) in sewage sludge are highly hydrophilic, and the destruction of EPS structure is very essential for the high-performance dewatering process. In this study, the peracetic acid lysis and chemical re-flocculation was used to achieve the volume reduction and dewaterability improvement of waste activated sludge. Moreover, dynamic variations of the floc morphology and EPS properties of sludge were also investigated. The results indicated that PAA treatment had very limited effect on sludge filterability, while filtration drying performance was effectively improved. PAA could effectively solubilize the sludge particle and destroy the protein-like substances, resulting in an efficient releasing of bound water. Sludge dewatering was enhanced under a low pH level after PAA oxiution, ascribing to the higher oxiutive ability of PAA under acid conditions. No integral sludge floc could be observed after PAA treatment at high dosages. Floc reformed after the additive of PAC and ferric chloride, meanwhile both filterability and dewaterability were improved. Furthermore, PAC performed better in improving sludge dewatering performance than ferric chloride due to its high adsorption and bridging abilities.%活性污泥中的胞外聚合物( EPS)高度亲水,破坏EPS结构是促使结合水释放的必要过程.为此,研究利用过氧乙酸( PAA)预氧化破解污泥和化学絮凝过程以同步实现污泥减量和脱水性改善,深入解析组合调理过程中污泥絮体形态特征及EPS分布和组成的变化特征.结果表明:PAA处理污泥对其过滤特性影响不大,但有效降低滤后泥饼的含水率;PAA能够有效破解污泥,破坏EPS中蛋白质类有机物,促使结合水释放;随着pH的降低,PAA对污泥脱水性的改善效果更佳,这主要是因为酸性环境有效提高了PAA对污泥 EPS的氧化效率;高剂量 PAA 处理污泥后未见到有完整结构的絮体.投加聚合氯化铝( PAC)和氯化铁

  15. Rapid prototyping in the development of image processing systems

    Science.gov (United States)

    von der Fecht, Arno; Kelm, Claus Thomas

    2004-08-01

    This contribution presents a rapid prototyping approach for the real-time demonstration of image processing algorithms. As an example EADS/LFK has developed a basic IR target tracking system implementing this approach. Traditionally in research and industry time-independent simulation of image processing algorithms on a host computer is processed. This method is good for demonstrating the algorithms' capabilities. Rarely done is a time-dependent simulation or even a real-time demonstration on a target platform to prove the real-time capabilities. In 1D signal processing applications time-dependent simulation and real-time demonstration has already been used for quite a while. For time-dependent simulation Simulink from The MathWorks has established as an industry standard. Combined with The MathWorks' Real-Time Workshop the simulation model can be transferred to a real-time target processor. The executable is generated automatically by the Real-Time Workshop directly out of the simulation model. In 2D signal processing applications like image processing The Mathworks' Matlab is commonly used for time-independent simulation. To achieve time-dependent simulation and real-time demonstration capabilities the algorithms can be transferred to Simulink, which in fact runs on top of Matlab. Additionally to increase the performance Simulink models or parts of them can be transferred to Xilinx FPGAs using Xilinx' System Generator. With a single model and the automatic workflow both, a time-dependant simulation and the real-time demonstration, are covered leading to an easy and flexible rapid prototyping approach. EADS/LFK is going to use this approach for a wider spectrum of IR image processing applications like automatic target recognition or image based navigation or imaging laser radar target recognition.

  16. Sewage sludge drying process integration with a waste-to-energy power plant.

    Science.gov (United States)

    Bianchini, A; Bonfiglioli, L; Pellegrini, M; Saccani, C

    2015-08-01

    Dewatered sewage sludge from Waste Water Treatment Plants (WWTPs) is encountering increasing problems associated with its disposal. Several solutions have been proposed in the last years regarding energy and materials recovery from sewage sludge. Current technological solutions have relevant limits as dewatered sewage sludge is characterized by a high water content (70-75% by weight), even if mechanically treated. A Refuse Derived Fuel (RDF) with good thermal characteristics in terms of Lower Heating Value (LHV) can be obtained if dewatered sludge is further processed, for example by a thermal drying stage. Sewage sludge thermal drying is not sustainable if the power is fed by primary energy sources, but can be appealing if waste heat, recovered from other processes, is used. A suitable integration can be realized between a WWTP and a waste-to-energy (WTE) power plant through the recovery of WTE waste heat as energy source for sewage sludge drying. In this paper, the properties of sewage sludge from three different WWTPs are studied. On the basis of the results obtained, a facility for the integration of sewage sludge drying within a WTE power plant is developed. Furthermore, energy and mass balances are set up in order to evaluate the benefits brought by the described integration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Reduction in energy usage during dry grind ethanol production by enhanced enzymatic dewatering of whole stillage: plant trial, process model and economic analysis

    Science.gov (United States)

    A plant trial was conducted at a 54 MGPY dry grind fuel ethanol facility to evaluate the use of enhanced water removal from whole stillage by enzyme addition during fermentation. Laboratory data had previously shown significant improvements in water removal that could potentially result in significa...

  18. Dissipation of triclosan, triclocarban, carbamazepine and naproxen in agricultural soil following surface or sub-surface application of dewatered municipal biosolids

    Energy Technology Data Exchange (ETDEWEB)

    Al-Rajab, Abdul Jabbar; Sabourin, Lyne [Agriculture and Agri-Food Canada, London, ON N5V 4T3 (Canada); Lapen, David R. [Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6 (Canada); Topp, Edward, E-mail: ed.topp@agr.gc.ca [Agriculture and Agri-Food Canada, London, ON N5V 4T3 (Canada); Department of Biology, Western University, London, ON N6A 5B7 (Canada)

    2015-04-15

    In many jurisdictions land application of municipal biosolids is a valued source of nutrients for crop production. The practice must be managed to ensure that crops and adjacent water are not subject to contamination by pharmaceuticals or other organic contaminants. The broad spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC), the anti-epileptic drug carbamazepine (CBZ), and the nonsteroidal anti-inflammatory drug naproxen (NAP) are widely used and are carried in biosolids. In the present study, the effect of biosolids and depth of placement in the soil profile on the rates of TCS, TCC, CBZ, and NAP dissipation were evaluated under semi-field conditions. Aggregates of dewatered municipal biosolids (DMBs) supplemented with {sup 14}C-labeled residues were applied either on the soil surface or in the subsurface of the soil profile, and incubated over several months under ambient outdoor conditions. The dissipation of TCS, TCC and NAP was significantly faster in sub-surface than surface applied biosolid aggregates. In contrast the dissipation rate for CBZ was the same in surface applied and incorporated aggregates. Overall, the present study has determined a significant effect of depth of placement on the dissipation rate of biodegradable molecules. - Highlights: • We characterized the soil fate of four organic contaminants carried in biosolids. • Biosolids were placed on the soil surface or incorporated within the soil profile. • Naproxen, triclosan and triclocarban were dissipated more rapidly when incorporated. • Depth of placement did not influence the rate of carbamazepine dissipation. • Soil incorporation of biosolids will result in more rapid dissipation of contaminants.

  19. Properties of water-soluble and insoluble particulate matter emitted from dewatered sewage sludge incineration in a pilot-scale ash melting furnace

    Energy Technology Data Exchange (ETDEWEB)

    Lian Zhang; Megumi Masui; Hiroharu Mizukoshi; Yoshihiko Ninomiya; Jugo Koketsu; Chikao Kanaoka [Chubu University, Aichi (Japan). Department of Applied Chemistry

    2008-05-15

    Emission of inorganic particulate matter (PM) from the incineration of dewatered sewage sludge has been investigated in a novel ash melting furnace. The sludge containing 79 wt% water was incinerated in an oxygen-enriched atmosphere at the primary temperature of 1400{sup o}C, and its unburned volatile was combusted at 1100{sup o}C in a secondary combustion chamber. A 13-stage low-pressure-impactor and the conventional impinger methods were employed for PM sampling at the outlet of the secondary combustion chamber. The results indicate that, PM is dominated by volatile and semi-volatile elements including Br, Cl, P, S, Na, K, Zn, As, Cu, Mn and Ni. Less refractory elements were found. PM has two major fractions: {lt}0.22 and {ge}0.22 {mu}m. Their chemical forms as well as water solubility are different between two fractions. The majority of Br, nearly half of Cl, and 40% of S and P are present in the small fraction. They are mostly water-soluble due to the association with alkali elements and heavy metals. The water-insoluble calcium sulfate and calcium/iron phosphate were, however, found in the large fraction of PM. Regarding the cations, the water solubilities of Na, K, Mn and Ni are close to their proportions partitioned into the small fraction of PM, since their water-soluble species were preferentially formed in this fraction. A relatively weak correlation for Al, Ca and As, while no such a correlation were found for Cu, Zn and Fe, due to the complex compounds formed for them. 31 refs., 11 figs., 5 tabs.

  20. Pharmaceuticals, hormones, anthropogenic waste indicators, and total estrogenicity in liquid and solid samples from municipal sludge stabilization and dewatering

    Science.gov (United States)

    Furlong, Edward T.; Gray, James L.; Quanrud, David M.; Teske, Sondra S.; Werner, Stephen L.; Esposito, Kathleen; Marine, Jeremy; Ela, Wendell P.; Zaugg, Steven D.; Phillips, Patrick J.; Stinson, Beverley

    2012-01-01

    The ubiquitous presence of pharmaceuticals and other emerging contaminants, or trace organic compounds, in surface water has resulted in research and monitoring efforts to identify contaminant sources to surface waters and to better understand loadings from these sources. Wastewater treatment plant discharges have been identified as an important point source of trace organic compounds to surface water and understanding the transport and transformation of these contaminants through wastewater treatment process is essential to controlling their introduction to receiving waters.

  1. Study on the Comparison between Prediction and Field Measurement of Surface Settlement Caused by Dewatering of Confined Water%降承压水引起地表沉降的预估与实测对比研究

    Institute of Scientific and Technical Information of China (English)

    张刚

    2013-01-01

    随着基坑工程不断向大深度、大面积方向发展,承压水降水引起的环境影响日益明显.本文采用以现场抽水试验参数为依据的数值模拟法对承压水降水引起的地表沉降进行了预测,并与基坑开挖和降水期间引起的地表总沉降进行了对比研究.实例分析结果表明,在基坑开挖和降水期间,承压水降水引起的沉降量占总沉降的比重比较大(约占30%);以现场抽水试验参数为依据的数值模拟法能较好地还原降水过程中地下水渗流场的分布形式、降深影响范围和沉降影响范围,为承压水降水引起的地表沉降研究提供了重要的工程资料和分析依据.%With the increase of depth and area of large-scale deep excavation,the environmental impact caused by dewatering of confined water has become increasingly clear.The numerical simulation method based on in-situ test was used to predict the surface settlement caused by dewatering of confined water,and then to compare the predicted value with the total settlement during the construction period.The results of engineering example showed that the setdement caused by dewatering of confined water accounted for a larger proportion of the total settlement (about 30%) ;this method could simulate the field distribution of groundwater,the influence scope of drop depth and the influence range of settlement very well,which provided engineering experience and theoretical basis for study of the settlement caused by dewatering of confined water.

  2. Dewatering of contaminated reservoir/lake sediment by using geotextile tubes aided by ultrasound%超声辅助絮凝强化污染底泥土工管袋脱水减容

    Institute of Scientific and Technical Information of China (English)

    张景辉; 刘朝辉; 卢丹; 王文茜

    2011-01-01

    Ultrasonic treatment combined with flocculants was used in dewatering of sediment by geotextile tube. For obtaining low sludge water mass fraction, the effect of the sequence of adding flocculants and ultrasonic on the dewatering performance was discussed. The optimal conditions of ultrasonic treatment were also determined. The results show that adding flocculants firstly and then ultrasonic treatment can achieve better dewatering performance. When the flocculants dosage is 5‰ (dry basis, mass fraction) , the ultrasonic energy density is 0.5 W/mL and treatment time is 10 s, the dehydration effect is the best. Finally, the pilot test of geotextile tube structure was performed. The result indicates that when flocculation mass fraction is 4‰, the dewatering performance of geotextile tube with ultrasound is better than that of the control group without ultrasound, and the curing time of geotextile tubes is shorten. Appropriate ultrasound can decrease the amount of flocculants, reduce costs and shorten the curing time of geotextile tubes, thus improving the efficiency.%将超声处理结合絮凝剂用于土工管袋脱水减容.以滤饼含水质量分数为优化指标,考察超声处理与添加絮凝剂的顺序对脱水性能的影响,并考察了超声处理的最优操作条件.结果表明:先添加絮凝剂再进行超声作用可取得较好的脱水效果,当絮凝剂的投加量(质量分数)为5‰(以干基计),超声波的能量密度为0.5 W/mL,作用时间为10 s,脱水效果最佳.最后进行土工管袋小试,结果表明在质量分数4‰絮凝剂的情况下,施加超声波作用时土工管袋的脱水效果优于未施加超声作用的5‰絮凝剂对照组,土工管袋固化时间缩短.适当的超声作用能减少絮凝剂使用量,降低成本,缩短土工管袋固化时间,提高效率.

  3. The disc method. A new method for selecting facilitations in flocculating sludge to be dewatered in centrifuges; Metodo de disco. Un nuevo metodo para la seleccion de floculantes en la floculacion de lodos a deshidratar en centrifugas

    Energy Technology Data Exchange (ETDEWEB)

    Canga Rodriguez, J.; Gutierrez Lavin, A.

    2002-07-01

    An experimental protocol was designed at a laboratory scale, in view of achieving the selection with different poly electrolytes related to the chemical conditioning (flocculation) of sewage sludge before dewatering it in a drying centrifuge. The method is based on a new parameter of quality of the formed floc, which measures its compaction when is submitted to a fix external strength. Some experimental tests have been introduced, whose results are numbers, avoiding all subjective aspects related to direct observation of flocs. (Author) 8 refs.

  4. 全套管钻机成孔复合型桩基降水施工新技术%Composite Pile Dewatering Construction New Technology of Hydraulic Casing Rotator Machine Drilling-holes

    Institute of Scientific and Technical Information of China (English)

    张素英

    2012-01-01

    针对基坑降水量小,围护结构外侧改移管线密布且交通繁忙无布设降水井场地,以及漂石地层中管井成孔困难和工期紧的问题,借助全套管钻机在直径1m围护桩施工时提出了一种新的复合型桩基降水方法.结合勘察报告将桩身加长,在桩底填滤料形成汲水区,用副钢筋笼内配套水泵、滤管与围护桩钢筋笼连接,排水管和水泵电线置于PVC套管中,沿围护桩钢筋笼升至地面,汲水区上部用细砂将预施围护桩隔离.计算显示围护桩内水位降深3m时,引起单桩沉降为0.12mm,小于桩顶总沉降值的10%.采用本工艺降低了施工成本,经济效益明显.%Because of small foundation excavation precipitation, pipeline densely covered on the outside of supporting structure and busy traffic, there isn ' t dewatering well sites and drilling holes is hard in boulder formation and tight schedule. A new composite pile formation dewatering method is proposed which 1 meter diameter supporting piles are drilled by hydraulic casing rotator machine. The piles body is extended with the survey report and filter material is filled in the bottom of piles to form water-absorbing area and an assistant reinforcing cage contains a pump and a filter tube which is welded to the supporting pile' reinforcing stage. Water pipeline and wire are protected in the PVC casing which is along the reinforcing stage up to the ground. In the top of the water-absorbing area, sand is filled to separate the prepared constructing supporting pile. Calculations show that the settlement of single pile caused by dewatering is 0. 12mm, when dewatering depth is 3m in a supporting pileless than 10% of the total settlement of the pile. The application of the technology reduces the construction cost and obtains economic benefit.

  5. Influence of the Hydrothermal Dewatering on the Gasification Characteristics of Typical Chinese Lignite%水热处理对我国典型褐煤气化特性的影响

    Institute of Scientific and Technical Information of China (English)

    葛立超; 张彦威; 应芝; 王智化; 周俊虎; 岑可法

    2013-01-01

    选取我国主要褐煤产区不同煤阶的3种典型褐煤,用水热处理对其进行脱水改性并研究改性前后褐煤 CO2气化特性的变化。结果表明,经过水热处理后,褐煤中的水分大幅度下降,最高降幅达87.31%,固定碳和热值上升,氧含量下降,煤阶参数(O/C原子比)下降,褐煤煤阶上升。水热处理过程中煤质结构的复杂重整导致煤焦孔径向微孔方向发展,先降低后增加,而比表面积和孔容呈现先上升后下降的趋势。煤质结构深度变化和煤阶的上升使得改性后褐煤的气化特性曲线向高温区移动,碳转化率达到50%时的气化温度上升。动力学计算结果表明,经过水热改性后气化反应活化能上升,反应级数发生变化。较高的水热处理终温和相对较低的原煤煤阶都使得水热脱水改性的效果更为显著。%The influences of hydrothermal dewatering (HTD) performed at different temperatures on the gasification characteristics of typical lignites with different metamorphic grades in China were investigated in this paper. Results show that the upgrading process significantly decreases the inherent moisture at a maximum degree of 87.31%and oxygen content, and increases calorific value and fixed carbon content. According to the oxygen/carbon ratio parameter, the coal rank increases. The complex changes occurred on coal structure during the HTD process lead to pore size of coal char develop to the microporous region, and the surface area and volume increase at first but then decrease. Due to the development of coal structure and the increment of coal rank, the gasification process of upgraded coal is delayed towards high temperature region, the temperature increases when carbon conversion rate reaches 50%. From the results of kinetic calculation, activation energy increases after the hydrothermal treatment, and the reaction order of mechanistic model is changed. Besides, all the changes

  6. Magnetic Fe3 O4 Microparticles Conditioning­Pressure Electro­osmotic Dewatering (MPEOD) of Sewage Sludge%微米 Fe3O4磁粉调理­压力电场污泥脱水工艺过程研究

    Institute of Scientific and Technical Information of China (English)

    钱旭; 王毅力; 赵丽

    2016-01-01

    研究了微米 Fe3 O4磁粉调理污泥的投加量的优化以及微米磁粉调理-压力电场污泥脱水工艺(MPEOD)的操作参数(电场作用时间、机械压力、电压)对脱水效果和能耗的影响,分析了磁化调理后污泥上清液、污泥絮体理化性质及接触能变化特征.结果表明,微米 Fe3 O4磁粉最佳调理投加量为0.15 g.g -1;结合能耗与脱水效果,电场作用时间、电压和机械压力分别确定为2 h、30~50 V 和400~600 kPa.当 MPEOD 工艺的机械压力、电场作用时间和电压分别为400 kPa、2 h 和50 V 时,污泥含水率由初始的99.18%降低至44.46%,水分脱除率和污泥减量化分别可达99.34%和98.30%,相应的能耗仅为0.0133 kW.h.kg -1.微米磁粉调理污泥时,絮凝作用机制的影响很小,污泥脱水性能得到提高的主要原因是微米磁粉大大降低了污泥颗粒间的路易斯酸碱作用,致使污泥絮体聚集,絮体间孔径增大,利于脱水.较之经典的 DLVO 理论,扩展后的 EDLVO 理论能准确描述污泥颗粒的凝聚及分散行为.%For magnetic Fe3 O4 microparticles conditioning-pressure electro-osmotic dewatering (MPEOD) process of activated sludge (AS), the effects of operating parameters (optimal dosage of Fe3 O4 , electric field duration, mechanical pressure and voltage) on the dewatering efficiency and energy consumption were investigated, and the optimal conditions were determined. Moreover, the properties of supernatant and sludge along MPEOD process were studied as well as the interaction force between the sludge biosolids. Taking the energy consumption into consideration, the results showed that the optimal dewatering effect for AS could be achieved with a magnetic Fe3 O4 microparticles dosage of 0. 15 g.g - 1 , an electric field duration of 2 h, a mechanical pressure of 400-600 kPa and a voltage of 30-50 V. When MPEOD was conducted at 400 kPa and 50 V for 2 h, the sludge reduction rate reached

  7. 真空轻型井点降水在深埋隧道未成岩富水粉细砂层施工中的应用%The Application of the Vacuum Light-Duty Well Point Dewatering Method to the Construction of I)ccp Tunnels in Non-Rocky, Water-Rich,Silty Sand Stratum

    Institute of Scientific and Technical Information of China (English)

    王菀; 蒋永强; 张文新; 陈天恩

    2012-01-01

    真空轻型井点降水在基坑和浅埋隧道施工中应用较多,但很少在深埋隧道中应用,对其降水效果也难以判断。依托兰渝铁路桃树坪隧道洞内降水工程,通过降水管如何设计与施工对真空轻型井点在洞内降水进行了研究。实践证明轻型井点降水在深埋隧道能够达到无水施工的效果,保证了隧道开挖过程中的砂层自稳,并对后续施工提出了改进建议。对类似工程具有参考意义。%The vacuum light-duty well point dewatering method is widely applied to the construction of foundation pits and shal- low-buried tunnels,but rarely applied to the construction of deep-buried tunnels, in which case lhe dewatering effect of the method is hard to estimate. Based on the dewatering project of the Taoshuping Tunnel of the Lanzhou-Chongqing Railway, a study is made,in the paper, of the effects of the vacuum light-duty well point dewatering method inside tunnels in regard to how to design and build the dewatering pipes,the result of which shows that by means of the vacuum light-duty well point dewate- ring method, the waterless construction inside deep-buried tunnels can be realized and the stability of the sandy stratum can be ensured during excavation. Some post-excavation construction advice for improvement is also proposed. The paper may serve as a useful reference for other similar projects in the future.

  8. Revealing the microbial community structure of clogging materials in dewatering wells differing in physico-chemical parameters in an open-cast mining area.

    Science.gov (United States)

    Wang, Juanjuan; Sickinger, Maren; Ciobota, Valerian; Herrmann, Martina; Rasch, Helfried; Rösch, Petra; Popp, Jürgen; Küsel, Kirsten

    2014-10-15

    Iron rich deposits cause clogging the pumps and pipes of dewatering wells in open-cast mines, interfering with their function; however, little is known about either the microbial community structure or their potential role in the formation of these deposits. The microbial diversity and abundance of iron-oxidizing and -reducing bacteria were compared in pipe deposit samples with different levels of encrustation from 16 wells at three lignite mining sites. The groundwater varied in pH values from slightly acidic (4.5) to neutral (7.3), Fe(II) concentrations from 0.48 to 7.55 mM, oxygen content from 1.8 to 5.8 mg L(-1), and dissolved organic carbon (DOC) from 1.43 to 12.59 mg L(-1). There were high numbers of bacterial 16S rRNA gene copies in deposits, up to 2.5 × 10(10) copies g(-1) wet weight. Pyrosequencing analysis of bacterial 16S rRNA genes revealed that Proteobacteria was the most abundant phylum (63.3% of the total reads on average), followed by Actinobacteria (10.2%) and Chloroflexi (6.4%). Gallionella-related sequences dominated the bacterial community of pipe deposits and accounted for 48% of total sequence reads. Pipe deposits with amorphous ferrihydrite and schwertmannite mostly contained Gallionella (up to 1.51 × 10(10) 16S rRNA gene copies g(-1) wet weight), while more crystalline deposits showed a higher bacterial diversity. Surprisingly, the abundance of Gallionella was not correlated with groundwater pH, oxygen, or DOC content. Sideroxydans-related 16S rRNA gene copy numbers were one order of magnitude less than Gallionella, followed by acidophilic Ferrovum-related groups. Iron reducing bacteria were detected at rather low abundance, as was expected given the low iron reduction potential, although they could be stimulated by lactate amendment. The overall high abundance of Gallionella suggests that microbes may make major contributions to pipe deposit formation irrespective of the water geochemistry. Their iron oxidation activity might

  9. Study on effect of chemical conditioning using different coagulants on sludge dewatering performance%不同混凝剂对污泥脱水性能的影响研究

    Institute of Scientific and Technical Information of China (English)

    牛美青; 张伟军; 王东升; 徐孝雅; 段晋明

    2012-01-01

    This study investigated sludge dewatering characteristics by using inorganic and organic coagulants.The effect of different coagulants on sludge dewatering was evaluated by means of specific resistance to filtration(SRF).Zeta potentials,the concentrations of protein,polysaccharide and DNA in the supernatant of the sewage sludge was also measured.In addition,three-dimensional excitation emission matrix fluorescence(3DEEM) was adopted to characterize the organic matters in supernatant.The results showed that the lowest intensity for SRF and 3DEEM analyses was observed when the ratio of spiked ferric chloride(FeCl3),polymeric aluminium(PAC) and polyaluminium chloude(HPAC) to dewatered sludge was 10%,while zeta potentials,protein concentrations,polysaccharide and DNA kept constant.It was noticeable that combination of inorganic and organic coagulants significantly improved the sludge dewaterability in comparison to that using single coagulant.Our results also demonstrated that the addition of inorganic prior to organic coagulant could provide notably higher efficiency for sludge dewatering than that spiking in reverse order.By combining coagulants in various ratios of coagulant to sludge,the order of optimal dewatering was:10%PAC+0.5%PAM10%FeCl3+0.5%PAM10%HPAC+0.5%PAM.%采用无机和有机混凝剂对污泥进行调理,通过测定污泥比阻、Zeta电位以及污泥上清液中蛋白质、多糖和DNA含量,同时结合污泥上清液的三维荧光光谱分析,研究了不同混凝剂及其投加量对污泥脱水性能的影响.结果表明:当聚合氯化铝(PAC)、高效聚合氯化铝(HPAC)和氯化铁(FeCl3)的投加量在干污泥量的10%附近时,污泥比阻值最小,同时三维荧光强度值也最小,Zeta电位以及上清液中蛋白质、多糖和DNA的含量基本趋于稳定.无机混凝剂与有机混凝剂联合作用调理污泥后其脱水效果明显优于单一混凝剂调理.有机混凝剂与

  10. 黄花和脱水污泥厌氧消化的温室气体减排研究%The greenhouse gases emissions reduction of anerobic digestion of solidago and dewatered sludge

    Institute of Scientific and Technical Information of China (English)

    戴晓虎; 王凯丽; 董滨; 吴冰

    2014-01-01

    According to the methodology by Intergovernmental Panel on Climate Change (IPCC), environmental and energetic impact of biogas production from the biomass composed of plant solidago canadensis L.(SC) and sewage sludge was evaluated in the study. Environmental evaluation focused on greenhouse gas (GHG) reduction, which was estimated from the methane yield through lab-scale anaerobic co-digestion of high-solid dewatered sludge (DS) and un-pretreated SC feedstocks with different volatile solid (VS) ratio of SC at mesophilic temperature. While energetic evaluation took into account the direct and indirect energy inputs of sludge storage and spreading, escaping of biogas from the digested effluent, and the addition of chemical fertilizers and reagents. These results indicated that anaerobic co-digestion of SC and DS to produce biogas was a high energy-efficient and environmentally friendly process. The net GHG emissions decreased with shortened SRT and increased portion of SC in the feedstock, and co-digestion of SC and DS at SRT of 20d with 50% VS addition of SC showed higher energy efficiency and significantly GHG reduction. Compared with the case with no SC, the addition of SC in the anaerobic digestion could achieve about 78 % reduction of net GHG emission. Besides, biogas plant operation was the largest energy consuming unit, in which stirring accounted for 39.5%~42.9% of the entire energy consumption of anaerobic digestion.%采用联合国政府间气候委员会(IPCC)推荐的方法,对植物加拿大一枝黄花和污泥生物质厌氧消化产沼气的环境和能量影响进行了评估。环境影响评估重点关注温室气体(GHG)减排,将加拿大一枝黄花和脱水污泥的中温小试厌氧消化的甲烷产率数据运用于GHG减排潜质的计算;能量评估包括污泥贮存及传播、消化液的沼气逃逸,及化学肥料和化学药剂的投加几个过程中的直接和间接的能量输入。结果表明,一枝黄花和脱水污泥联

  11. Use of the GranuFlow Process in Coal Preparation Plants to Improve Energy Recovery and Reduce Coal Processing Wastes

    Energy Technology Data Exchange (ETDEWEB)

    Glenn A. Shirey; David J. Akers

    2005-12-31

    With the increasing use of screen-bowl centrifuges in today's fine coal cleaning circuits, a significant amount of low-ash, high-Btu coal can be lost during the dewatering step due to the difficulty in capturing coal of this size consist (< 100 mesh or 0.15mm). The GranuFlow{trademark} technology, developed and patented by an in-house research group at DOE-NETL, involves the addition of an emulsified mixture of high-molecular-weight hydrocarbons to a slurry of finesized coal before cleaning and/or mechanical dewatering. The binder selectively agglomerates the coal, but not the clays or other mineral matter. In practice, the binder is applied so as to contact the finest possible size fraction first (for example, froth flotation product) as agglomeration of this fraction produces the best result for a given concentration of binder. Increasing the size consist of the fine-sized coal stream reduces the loss of coal solids to the waste effluent streams from the screen bowl centrifuge circuit. In addition, the agglomerated coal dewaters better and is less dusty. The binder can also serve as a flotation conditioner and may provide freeze protection. The overall objective of the project is to generate all necessary information and data required to commercialize the GranuFlow{trademark} Technology. The technology was evaluated under full-scale operating conditions at three commercial coal preparation plants to determine operating performance and economics. The handling, storage, and combustion properties of the coal produced by this process were compared to untreated coal during a power plant combustion test.

  12. Educação online e mudanças nas práticas comunicacionais de discentes no sertão do Piauí na modalidade EAD

    Directory of Open Access Journals (Sweden)

    Juscelino Francisco do Nascimento

    2016-07-01

    Full Text Available This paper aims at presenting the communicational appropriations of Distance Education students of the Federal University of Piauí, given that this modality allows changes in their communicational/educational practices. The systematic problem recognizes that the communicational/educational process can be effected on the Internet, basically in digital environments. However, it seemed relevant the perception of "how" it is processed. It is this overlap that our research problem arises, which, strictly speaking, involves the "how" is given communication in distance education, and the circulation of this process in digital educational/social platforms. We applied a questionnaire for finding data on the lives of students, we also mapped practices on the internet before and after the distance education course as well as their personal characteristics, the flows and communication migrations. The authors that guided these studies involved the relationship established between the students and cyberculture, being endorsed, among others, by Citelli and Costa (2011, Bonin 2011 Lopes (2006, Maldonado (2011. Freire (1983 and Hall (2005. The results indicate that the subjects started to use the internet as a compulsory learning tool, reconfiguring the learning process and marking the establishment of a mediated education contract - MidEC.

  13. Characterization of changes in floc morphology, extracellular polymeric substances and heavy metals speciation of anaerobically digested biosolid under treatment with a novel chelated-Fe(2+) catalyzed Fenton process.

    Science.gov (United States)

    He, Juanjuan; Yang, Peng; Zhang, Weijun; Cao, Bingdi; Xia, Hua; Luo, Xi; Wang, Dongsheng

    2017-07-03

    A novel chelated-Fe(2+) catalyzed Fenton process (CCFP) was developed to enhance dewatering performance of anaerobically digested biosolid, and changes in floc morphology, extracellular polymeric substances (EPS) and heavy metals speciation were also investigated. The results showed that addition of chelating agents caused EPS solubilization by binding multivalent cations. Like traditional Fenton, CCFP performed well in improving anaerobically digested sludge dewatering property. The highly active radicals (OH, O2(-)) produced in classical Fenton and CCFP were responsible for sludge flocs destruction and consequently degradation of biopolymers into small molecules. Furthermore, more plentiful pores and channels were presented in cake after Fenton treatment, which was conducive to water drainage under mechanical compression. Additionally, a portion of active heavy metals in the form of oxidizable and reducible states were dissolved under CCFP. Therefore, CCFP could greatly simplify the operating procedure of Fenton conditioning and improve its process adaptability for harmless treatment of biological sludge. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. 河床砂石地质状况深基坑降水及开挖施工技术%Deep foundation dewatering and excavation construction technologies of riverbed with sandy soil geological conditions

    Institute of Scientific and Technical Information of China (English)

    光俊民

    2015-01-01

    Combining with coarse grid foundation construction example of Gansu Jingchuan sewage treatment engineering,introduces foundation construction schemes,and describes critical construction technology procedures and construction methods controlling essentials of dewatering,ex-cavation and cushion construction. Through monitoring foundation slope and water level,it finally puts forward safety guarantee measures.%结合甘肃泾川污水处理工程粗格栅基坑施工实例,介绍了基坑施工的方案,对降水、开挖、垫层施工等关键工序的施工方法控制要点进行了阐述,通过对基坑边坡及水位的监测,提出了安全保证措施。

  15. Research on vacuum membrane distillation technique disposing of high concentration inorganic salt reverse osmosis dense dewatering%减压膜蒸馏技术处理无机高盐 RO 浓排水研究

    Institute of Scientific and Technical Information of China (English)

    郭建中; 路全忠; 杨才伟

    2012-01-01

      针对无机高盐 RO 浓排水具有含盐量高难处理的特点,本文研究了减压膜蒸馏技术处理无机高盐RO 浓排水试验阶段中不同料液温度、真空度、流速对膜通量的影响.结果表明:料液温度、真空度、流速与膜通量存在相关性.随着料液温度和真空度的提高,膜通量会相应增加;随着料液流速的增加膜通量也有增加,但流速小于0.2 m/s 时对膜通量的影响明显,当流速大于0.2m/s 时对膜通量影响小%  Aimed at the characteristic of high salinity and difficult dispose of high concentration inorganic salt reverse osmosis dewatering, this paper studies the vacuum membrane distillation technique dispose of high concentration inorganic salt reverse osmosis dewatering, and analyse the influence of different vacuum, material fluid temperature, flow velocity to membrane flux. The result shows that there is a correlation between membrane flux and vacuum, material fluid temperature and flow velocity. With increasing of vacuum and material fluid temperature, membrane flux increased accordingly; and when the velocity increased and membrane flux increased at the same time. With the velocity was less than 0.2 m/s, the influence to membrane flux came to be obvious, when the velocity was above 0.2 m/s, the influence to membrane flux went light.

  16. Production of Bamboo Fiber Reinforced Fibrillated Poly(Lactic Acid) (PLA) Material Obtained by a Papermaking Process

    Institute of Scientific and Technical Information of China (English)

    WANG Ruibin; YANG Rendang; YANG Fei

    2015-01-01

    A devised beating process was applied, which enabled the formation of slurry consisting of uniformly dispersed fibrillated polylactic acid (PLA) fibers with bamboo fiber, and the polymer material was obtained by a conventional papermaking process. Owing to the fast dewatering time, good repeatability and the facility to manufacture on a large scale, this process was used. It was revealed that the beaten PLA fiber was overall in machinery extrusion by the results of optical microscope and scanning electron microscope (SEM) observations. The improvement in the tensile index, burst index, tear index and other mechanical properties was considered as a key benefit as a result of adding bamboo fiber.

  17. EAD na contabilidade: uma análise de sua efetivação de uso no curso de ciências contábeis da Universidade Federal do Rio Grande do Sul

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Kovara Vieira

    2016-05-01

    Full Text Available This study aims to demonstrate with which approach and in which disciplines Distance Education (DE can improve learning, from the perception of the students of Accounting Course of the Federal University of Rio Grande do Sul, Brazil. The study starts from the issue relating to the perceptions of students of accountancy course regarding to which disciplines may have enhanced their learning with this type of education. Therefore, a quantitative and explanatory focus is used as a methodology of research, applied through methodological procedures of case study, by use of questionnaire. All results showed that the bulk of the students integrate the young age group and have great abilities in the use of technological devices. They also suggest that the disciplines that are not directly related to the accounting area should be taught in the distance format, that there is need of teacher’s encouragement so that students to participate in forums and distance learning activities as well as the unwillingness of students to performing of a course taught entirely in a distance way. Due to the results obtained with the application of this research, it is suggested that UFRGS should establish an assessment of the subjects that could be offered in a distance way, and teachers could also be trained, aiming to improve the learning process.

  18. Evaluation of a novel fine coal dry cleaning process at Greenfields Coal Company

    Energy Technology Data Exchange (ETDEWEB)

    Bratton, R.; Luttrell, G.; Kasindorf, H.; McGraw, G.; Robbins, R. [Virginia Polytechnic Institute & State University, Blacksburg, VA (United States)

    2010-07-01

    Coal mining and processing operations have in the past and continue to create large tonnages of fine coal and waste particles. While technological advances in wet processing has made it possible to efficiently recover coal fines, difficulties associated with dewatering make these fine particles unattractive economically for most coal markets. A novel system has been developed for cleaning fine raw coal utilizing a multistage dry classification process that removes the clay particles that are typically much smaller than the majority of the clean coal particles and that reduces the product surface moisture to as low as 1%. In this article, the novel dry coal-cleaning process under license to Greenfields Coal Company was evaluated. The classification process offers a viable alternative to traditional wet processing and dewatering of the fine particles, especially for operations recovering abandoned impoundments where a sufficient water source and/or a waste slurry disposal site are unavailable. This article presents the separation performance and operating results obtained from field testing with a 2t/hr pilot-scale unit located at an abandoned impoundment in southern West Virginia.

  19. DEVELOPMENT AND DEMONSTRATION OF INTEGRATED CARBON RECOVERY SYSTEMS FROM FINE COAL PROCESSING WASTE

    Energy Technology Data Exchange (ETDEWEB)

    Y.P. Chugh; D. Patil; A. Patwardhan; R.Q. Honaker; B.K. Parekh; D. Tao; Latif Khan

    2000-07-01

    The project involves the development of an efficient, environmentally friendly system for the economical recovery of carbon from fine-coal refuse ponds. The project will be conducted in two phases. Phase I was involved in the development and evaluation of process equipment and techniques to be used in carbon recovery, product dewatering and reconstitution, and refuse management. Phase II will integrate the various units into a continuously operating circuit that will be demonstrated at a site selected based on the results presented in this study.

  20. Application of Algae as Cosubstrate To Enhance the Processability of Willow Wood for Continuous Hydrothermal Liquefaction

    DEFF Research Database (Denmark)

    Sintamarean, Iulia-Maria; Pedersen, Thomas Helmer; Zhao, Xueli

    2017-01-01

    This work proposes a novel strategy to improve the continuous processing of wood slurries in hydrothermal liquefaction systems by coprocessing with algae. Of all algae tested, brown seaweeds and microalgae perform best in preventing slurries dewatering, the main reason for pumpability issues...... with wood slurries. Rheological tests (viscosity–shear rate profile) indicate that the addition of these two algae to the wood slurry causes the highest increase in viscosity, which coincides with improved wood slurries stability and pumpability. Hydrothermal liquefaction of wood-algae slurries at 400 °C...

  1. Comparison of residual sludge dewatering and stabilization between reed beds and conventional sludge drying bed%芦苇床与传统干化床污泥脱水和稳定性能比较

    Institute of Scientific and Technical Information of China (English)

    孙红杰; 崔玉波; 王芳; 刘颖慧; 包双翔

    2011-01-01

    The article is aimed to present the results of our comparative study of residual sludge dewatering and stabilization between reed beds and conventional sludge drying bed. As is known, sludge drying reed beds appear as a new and alternative treating method, whose advantages are low energy demands, reduced operating and maintenance costs, with little environmental impact. For the purpose of understanding residual sludge dewatering and stabilization features in sludge drying reed beds, we have laid out a pilot scale experiment which lasts three years on testing three sludge drying beds. Bed I was un-planted, known as the control bed; bed Ⅱ and bed Ⅲ were planted with reeds. The bottoms of bed I and bed H are connected to the atmosphere through perforated PVC ventilation tubes through the overlying porous medium. The first two years were sludge loading period, whereas the beds in the third year were taken as their natural stabilization period. At the same time, the beds were fed during plant growing season, and rested in frozen up period, with each bed loaded totally 8.4 meters of residual sludge. Samples of influent sludge and sludge accumulated in the beds were analyzed for organic matter and water content. The results of our experiments can be stated as follows: the organic matter removal and sludge stabilization in the beds was found going on progressively, the planted sludge drying reed beds Ⅱ and Ⅲ prove to be able to remove the organic matter from the residual sludge more effectively than the unplanted bed Ⅰ , in the corresponding rate of 54.5% , 51.5% and 43.3% in organic matter degradation efficiencies, and the ventilation contributes to organic matter degradation and transformation. However, beds Ⅰ and Ⅱ with ventilation tubes possess higher sludge dewatering efficiencies than bed Ⅲ, in the corresponding average rate of 33.69% , 34.15% and 32.79% of dewatering efficiencies. And in the end of the third year, minimum organic matter content in

  2. Model analysis of energy consumption and greenhouse gas emissions of sewage sludge treatment systems with different processes and scales.

    Science.gov (United States)

    Soda, S; Iwai, Y; Sei, K; Shimod, Y; Ike, M

    2010-01-01

    An energy consumption model was developed for evaluating sewage sludge treatment plants (SSTPs) incorporating various treatment processes such as thickening, anaerobic digestion, dewatering, incineration, and melting. Based on data analyses from SSTPs in Osaka, Japan, electricity consumption intensities for thickening, anaerobic digestion, dewatering, incineration, and melting and heat consumption intensities for anaerobic digestion, incineration, and melting were expressed as functions of sludge-loading on each unit process. The model was applied for predicting the energy consumption and greenhouse gas (GHG) emissions of SSTPs using various treatment processes and power and heat generation processes using digestion gas. Results showed that SSTPs lacking incineration and melting processes but having power generation processes showed excess energy production at the high sludge-loading rate. Energy consumption of the SSTPs without incineration and melting processes were low, but their GHG emissions were high because of CH(4) and N(2)O emissions from sludge cake at the landfill site. Incineration and melting processes consume much energy, but have lower CH(4) and N(2)O emissions.

  3. Waste management in the meat processing industry: Conversion of paunch and DAF sludge into solid fuel.

    Science.gov (United States)

    Hamawand, Ihsan; Pittaway, Pam; Lewis, Larry; Chakrabarty, Sayan; Caldwell, Justin; Eberhard, Jochen; Chakraborty, Arpita

    2017-02-01

    This article addresses the novel dewatering process of immersion-frying of paunch and dissolved air flotation (DAF) sludge to produce high energy pellets. Literature have been analysed to address the feasibility of replacing conventional boiler fuel at meat processing facilities with high energy paunch-DAF sludge pellets (capsules). The value proposition of pelleting and frying this mixture into energy pellets is based on a Cost-Benefit Analysis (CBA). The CBA is based on information derived from the literature and consultation with the Australian Meat Processing Industry. The calorific properties of a mixture of paunch cake solids and DAF sludge were predicted from literature and industry consultation to validate the product. This study shows that the concept of pelletizing and frying paunch is economically feasible. The complete frying and dewatering of the paunch and DAF sludge mixture produces pellets with energy content per kilogram equivalent to coal. The estimated cost of this new product is half the price of coal and the payback period is estimated to be between 1.8 and 3.2years. Further research is required for proof of concept, and to identify the technical challenges associated with integrating this technology into existing meat processing plants. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  4. 不同调理方案下污泥脱水性能评价指标的相关性研究%Relationship of Evaluation Indexes of Sludge Dewatering Performance Under Different Conditioning Programs

    Institute of Scientific and Technical Information of China (English)

    刘欢; 杨家宽; 时亚飞; 李野; 何姝

    2011-01-01

    Performances of different sludge conditioners are difficult to evaluate due to the use of various evaluation indexes.Taking several traditional sludge conditioners,e.g.PAM,FeCl3 and inorganic composite conditioners as examples and five evaluation indexes include specific resistance to filtration(SRF),capillary suction time(CST),sludge settling performance,water content of sludge cake and dewatering efficiency,were investigated respectively in order to study the correlation among those indexes.The results indicate a significant positive linear correlation between SRF and CST(R2 values are 0.96 and 0.93,respectively) after adding different types of conditioners or different amount of conditioners.While they can precisely reflect plate and frame filter press efficiency,but they fail to predict the effects of centrifugal dewatering.Sludge settling performance presents the similar tendencies with SRF and CST.Since there is only limited correlation rather than strict correspondence between water content of sludge cake and dewatering efficiency.Thus,both factors should be considered synthetically in optimizing dosage performances.%污泥脱水性能评价指标选取不同导致目前调理剂难以进行比选.以聚丙烯酰胺(PAM)、FeCl3及无机复合物等几种常用的调理剂为例,通过测定调理后污泥比阻(SRF)、毛细吸水时间(CST)、污泥沉降性能、泥饼含水率及污泥脱水率5个常用评价指标,探讨了各种指标之间的相关性.结果表明,当分别使用不同种类和不同投加量的调理剂时,SRF与CST具有良好的正线性相关性(R2分别为0.96、0.93).SRF及CST均能准确地反映污泥板框压滤脱水性能,但不能很好地预测离心脱水效果.污泥的沉降性能与SRF、CST大致呈现出相同的变化规律.由于泥饼含水率与脱水率存在一定的相关性,但不存在对应性,因此优选调理剂时,建议综合考虑泥饼含水率和脱水率.

  5. 微波对污水污泥脱水特性及形态影响%Impacts of Microwave on Dewater Ability and Morphological Feature of Sewage Sludge

    Institute of Scientific and Technical Information of China (English)

    周翠红; 常俊英; 陈家庆; 孔惠

    2013-01-01

    研究了微波加热温度和温升速率对污泥脱水特性的影响,并对微波处理后污泥的CST、粘度、沉降比、含水率、上清液COD含量、Zeta电位、形态学特征进行了测试与分析.实验结果表明,温升速率为10℃/min,加热到70~80℃时中水站污泥脱水特性较好.随温度上升,污水处理厂污泥的SV、粘度、含水率相应降低,COD含量逐渐增加;对比直接从污泥图像与据污泥颗粒的粒径分布得到分形维数与粒径,发现在不同的加热条件下污泥形态有明显变化,加热到60~80℃时脱水特性较好,70℃时含水率最低为83.12%.%Firstly the impacts of heating temperature and rate of microwave on dewater ability and morphological feature of sewage sludge were investigated. Then CST, viscosity, SV, moisture content, COD, Zeta electric potential and morphological feature were tested. It is shown that the lowest CST of reclaimed water plant is 4. 2s while the heating rate is 10℃/min and heating temperature is 80℃. SV, viscosity, moisture content of waste water plant sludge decrease and COD increases when heating temperature is higher. It is indicated that morphology of sludge changes under different heating conditions from fractal dimension and particle size data which is analyzed from image and calculated from cumulative weight percentage undersize of sludge particle. After 60~80℃ microwave pretreatment, dewater ability is proved.

  6. Research on Settling and Dewatering Characteristics of Sludge by Radiation%辐射技术强化污泥沉降与脱水特性的实验研究

    Institute of Scientific and Technical Information of China (English)

    周翠红; 曹春艳

    2011-01-01

    主要研究辐射技术对污泥沉降与脱水特性的影响,实验采用某污水处理厂的样品经过微波、超声辐射改性后,对毛细吸水时间(CST)、粘度、污泥沉降比(SV)、含水率、上清液的COD浓度、Zeta电位、形态学特征的变化情况进行了研究.实验结果表明,微波辐射后污泥颗粒的平均粒度由33.551 μm降低到28.979μm,分形维数在2.8左右,图像显微分析表明微波调质后污泥有粗大化现象;超声辐射后污泥的粒度由33.551 μm降低到9.435 μm,分形维数在2.9左右,超声调质后污泥颗粒较小;利用Origin8.0软件对污泥脱水特性与污泥含水率进行分析,建立了污泥脱水特性的模型有助于在线预测污泥含水率.%Settling and dewatering characteristics of sludge from sewage treatment plant by radiation including microwave and ultrasound were studied. CST, viscosity, settling ratio, water content, COD, Zeta electric potential and morphological were tested. After microwave modification, particle size of sludge reduced from 33.551 μm to 28.979 μm, fractal dimension was about 2.8, and microscopic image analysis showed that the particle of sludge became coarsening. After ultrasound modification, particle size of sludge reduced from 33.551μm to 9.435u.m, fractal dimension was about 2.9, and the smaller particles were observed after ultrasound. Origin 8.0 software was used to analyze dewatering characteristics of sludge and water content, and to establish the model for the prediction of moisture content of sludge online.

  7. Clean-up and disposal process of polluted sediments from urban rivers

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, the discussion is concentrated on the properties of the polluted sediments and the combination of clean-up and disposal process for the upper layer heavily polluted sediments with good flowability. Based on the systematic analyses of various clean-up processes, a suitable engineering process has been evaluated and recommended. The process has been applied to the river reclamation in Yangpu District of Shanghai metropolis. An improved centrifuge is used for dewatering the dredged sludge,which plays an important role in the combination of clean-up and disposal process. The assessment of the engineering process shows its environmental and technical economy feasibility, which is much better than that of traditional dredging-disposal processes.

  8. On dewatering construction ontrol at deep foundation pit project of rail traffic stations%谈轨道交通车站深基坑工程降水施工控制

    Institute of Scientific and Technical Information of China (English)

    李贵保

    2014-01-01

    Taking the foundation pit project at Olympics Sport Center Station of Underground Stations along Lanzhou Rail Traffic as the example, the paper undertakes the calculation and research on the foundation pit dewatering parameter according to its features of weak foundation pit com-paction,uneven partical distribution,and insufficient pit stability,illustrates the requirements for the construction supervision,and points out the emergency treatment measrues,so as to ensure the safety of the foundation pit.%以兰州轨道交通地下车站奥体中心站基坑工程为例,针对基坑胶结程度差、颗粒分布不均匀、坑壁稳定性差的特点,对基坑降水参数进行了计算研究,阐明了施工监测的要求,并提出了应急处理措施,以确保基坑安全。

  9. Drying of Dewatered Sludge from Large-scale WWTP by Boiler Flue Gas Residual Heat in Power Plant%大型污水厂利用电厂锅炉烟气余热干化脱水污泥

    Institute of Scientific and Technical Information of China (English)

    孙卫东; 姜立安; 汪泳; 黄志强; 严平; 肖斌; 李辉; 赖志强

    2012-01-01

    Shenzhen Nanshan WWTP is near the Shenzhen Nanshan Power Plant, so the sludge treatment has an advantage in the use of residual heat from the power plant. Through reconstructing the heating surface of boiler, the boiler flue gas residual heat can be transformed into the heating source for sludge drying, which can reduce the water content of dewatered sludge from 80% to 10% -30%. The dried sludge can be used as the raw materials for auxiliary fuel, organic fertilizer and building material industry, and the comprehensive utilization of the waste is achieved.%深圳S污水处理厂毗邻热电厂,污泥处理具备了利用电厂余热资源的优势.通过对电厂锅炉受热面进行改造,将烟气余热转换为污泥干化的热源使用,可将污水厂脱水污泥的含水率从80%降至10%~30%.干化污泥可用作辅助燃料、有机制肥及建材等行业原料,实现了废物的综合利用.

  10. Effect of Ferric Chloride on the Properties of Biological Sludge in Co-precipitation Phosphorus Removal Process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhibin; LI Yi; WEI Leilei; L(U) Yufeng; WANG Meng; GAO Baoyu

    2013-01-01

    This paper studied the effect of ferric chloride on waste sludge digestion,dewatering and sedimentation under the optimized doses in co-precipitation phosphorus removal process.The experimental results showed that the concentration of mixed liquid suspended solid (MLSS) was 2436 mg·L-1 and 2385 mg·L-1 in co-precipitation phosphorus removal process (CPR) and biological phosphorous removal process (BPR),respectively.The sludge reduction ratio for each process was 22.6% and 24.6% in aerobic digestion,and 27.6% and 29.9% in anaerobic digestion,respectively.Due to the addition of chemical to the end of aeration tank,the sludge content of CPR was slightly higher than that of BPR,but the sludge reduction rate for both processes had no distinct difference.The sludge volume index (SVI) and sludge specific resistance of BPR were 126 ml·g-1 and 11.7×1012 m·kg-1,respectively,while those of CPR were only 98 ml·g-1 and 7.1×1012 m·kg-1,indicating that CPR chemical could improve sludge settling and dewatering.

  11. 深埋隧洞外深井群降水试验及方案研究%Study on Deep Wells Dewatering Test and Precipitation Scheme Outside the Deep-Lying Tunnel

    Institute of Scientific and Technical Information of China (English)

    薛振声; 成益洋; 张社祥

    2016-01-01

    针对小浪底南岸灌区自流总干(引黄入洛)工程隧洞新近系围岩中地下水处理问题,引入了洞外深井群超前降水技术,并采用多孔稳定流抽水试验方法进行现场抽水试验,计算渗透系数和影响半径。建立FLAC3D流-固耦合模型进行三维渗流数值分析,确定深井群降水方案。抽水试验表明:测井C2、C3、C4同时抽水,观测井G1水位降深在开始抽水后5.5 h达到最大,水位降深达13.09 m,观测井G1底部高程低于平洞底板高程约10 m,说明降水效果明显。通过三维渗流数值计算,对各深井群降水方案对比分析,确定洞外深井群布井方案:沿平洞轴线两侧约5 m、交错间隔50~75 m布设降水井,井深110~120 m,井深进入平洞底板深度不小于50 m。%In order to solve the problem of groundwater treatment for constructing in the neogene surrounding rock of the Yellow River into Luoyang tunnel, the advance deep wells precipitation technology outside the deep⁃lying tunnel was introduced. The porous stable flow test method was adopted to do the the deep wells pumping test and the permeability coefficient and influence radius were calculated. Based on the test, the three⁃dimensional finite element seepage model of flac3D was built to determine the precipitation schemes of deep wells pumping scheme. The pumping test shows the drawdown of water table in observation well G1 reaches to the maximum value of 13.09m after continuing 5.5 h pumping groundwater from the pumping wells of C2 , C3 and C4 at the same time, and the water level at the bottom of observation well G1 is 10 m lower than that of the elevation of tunnel floor, so the test of dewatering effect of deep wells has obvious effect. The dewatering effect of deep wells seepage precipitation schemes was comparatively analyzed and determined by three⁃dimensional finite element seepage numerical as that the deep wells pumping are staggered

  12. Evaluation of anaerobic digestion processes for short sludge-age waste activated sludge combined with anammox treatment of digestate liquor.

    Science.gov (United States)

    Ge, Huoqing; Batstone, Damien; Keller, Jurg

    2016-01-01

    The need to reduce energy input and enhance energy recovery from wastewater is driving renewed interest in high-rate activated sludge treatment (i.e. short hydraulic and solids retention times (HRT and SRT, respectively)). This process generates short SRT activated sludge stream, which should be highly degradable. However, the evaluation of anaerobic digestion of short SRT sludge has been limited. This paper assesses anaerobic digestion of short SRT sludge digestion derived from meat processing wastewater under thermophilic and mesophilic conditions. The thermophilic digestion system (55°C) achieved 60 and 68% volatile solids destruction at 8 day and 10 day HRT, respectively, compared with 50% in the mesophilic digestion system (35°C, 10 day HRT). The digestion effluents from the thermophilic (8-10 day HRT) and mesophilic systems were stable, as assessed by residual methane potentials. The ammonia rich sludge dewatering liquor was effectively treated by a batch anammox process, which exhibited comparable nitrogen removal rate as the tests using a control synthetic ammonia solution, indicating that the dewatering liquor did not have inhibiting/toxic effects on the anammox activity.

  13. Biodiesel production from wet microalgae feedstock using sequential wet extraction/transesterification and direct transesterification processes.

    Science.gov (United States)

    Chen, Ching-Lung; Huang, Chien-Chang; Ho, Kao-Chia; Hsiao, Ping-Xuan; Wu, Meng-Shan; Chang, Jo-Shu

    2015-10-01

    Although producing biodiesel from microalgae seems promising, there is still a lack of technology for the quick and cost-effective conversion of biodiesel from wet microalgae. This study was aimed to develop a novel microalgal biodiesel producing method, consisting of an open system of microwave disruption, partial dewatering (via combination of methanol treatment and low-speed centrifugation), oil extraction, and transesterification without the pre-removal of the co-solvent, using Chlamydomonas sp. JSC4 with 68.7 wt% water content as the feedstock. Direct transesterification with the disrupted wet microalgae was also conducted. The biomass content of the wet microalgae increased to 56.6 and 60.5 wt%, respectively, after microwave disruption and partial dewatering. About 96.2% oil recovery was achieved under the conditions of: extraction temperature, 45°C; hexane/methanol ratio, 3:1; extraction time, 80 min. Transesterification of the extracted oil reached 97.2% conversion within 15 min at 45°C and 6:1 solvent/methanol ratio with simultaneous Chlorophyll removal during the process. Nearly 100% biodiesel conversion was also obtained while conducting direct transesterification of the disrupted oil-bearing microalgal biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. 纤维素酶对废纸浆废水生化污泥脱水性能的影响%Effect of cellulase on sludge dewatering performance of recovered pulp wastewater

    Institute of Scientific and Technical Information of China (English)

    张安龙; 赵登; 景立明; 罗清

    2014-01-01

    采用纤维素酶处理废纸浆废水生化污泥,讨论了其影响因素.通过单因素实验和正交试验得到最佳工艺条件:酶用量为2.25U·g -1,温度为55℃,反应时间为75min,其处理后污泥的沉降性能得到很大程度的改善.红外光谱图和电镜扫描分析表明:经酶处理后污泥化学性质发生改变,细小颗粒污泥均匀分布,其污泥的结构紧密易实现固液分离,从而提高了污泥脱水性能.%The cellulase is applied in the treatment of biochemical sludge of recovered pulp wastewater and the influencing factors are discussed in this paper .Through the single factor experiment and orthogonal experiment to determine the optimal reaction conditions ,the re-sults show that :when dosage of enzyme is 2 .25 U · g -1 ,the temperature is 55 ℃ ,the reac-tion time is 75 min ,and the sludge settling properties has a large degree of improvement . Infrared spectrum and SEM analysis showed that cellulase treatment biochemical sludge can make sludge chemical properties change and fine granular sludge uniformly distribute ,then the compact sludge structure is easy to realize solid-liquid separation ,thereby improving the dewatering performance of sludge .

  15. Meeting processing challenges in clean coal utilization

    Energy Technology Data Exchange (ETDEWEB)

    Chugh, Y.P.; Patwardhan, A.; Barnwal, J.P. [Southern Illinois University, Carbondale, IL (United States). Dept. of Mining and Mineral Resources Engineering

    2003-02-01

    The paper identifies some of the major challenges facing processing for clean coal utilization today. Some of the ongoing research at Southern Illinois University in the areas of plant optimization, fine coal cleaning and dewatering, fine coal-water slurry combustion, development of multiple products and mine-mouth utilization for lower grade products, and co-management of coal processing wastes and coal combustion byproducts underground, or as a cover material suitable for vegetation in surface mine reclamation is approaching commercialization. Additional research has been initiated recently in low cost desulfurization for SOx reduction, and/or reducing scrubbing costs. An integrated approach to evaluating processing unit operation for enhancing overall profitability of a mining complex is paying dividends. The approach is a good tool to assess role of processing for clean coal utilization in any setting. The authors have attempted to demonstrate its use for Indian coals. They plan to develop a computer program for making this integrated assessment approach more user friendly. 33 refs., 4 figs., 10 tabs.

  16. 疏干水深度处理工艺路线设计与分析%Design and Analysis of Technical Route for Mine Dewatering Water Treatment

    Institute of Scientific and Technical Information of China (English)

    汪岚; 蔡井刚; 胡治平

    2016-01-01

    通过介绍矿井疏干水的水质特点,分析了污染物去除的化学机理;根据某处典型的疏干水水样数据,设计一套包含去除重金属、硬度、硫酸根等污染物的水处理工艺路线,重点对工艺过程中的两级软化水质变化数据进行分析和计算,最后评估了该工艺路线对疏干水净化处理的预期处理效果,并讨论了工艺路线应用实施的可行性。为矿井疏干水在火电厂的综合利用提供了技术参考。%Through the mine drainage water quality characteristic, the chemical mechanism of pollutants removal was analyzed. According to somewhere typical drainage water sample data, a water treatment process for removal of heavy metal, hardness, the sulfate and other pollutants was designed, focus on process of two-stage softening water quality changes in the data analysis and calculation, the desired treatment effect of the sparse dry water purification by the process route was evaluated, and the feasibility of process route application was discussed. It provided a technical reference for the comprehensive utilization of mine drainage water in thermal power plant.

  17. Application of Tailings Dewatering Screen in the Tailings Dry-Discharge System%尾矿脱水筛在尾矿干排系统中的技术应用

    Institute of Scientific and Technical Information of China (English)

    李怀志

    2014-01-01

    The new technology of tailings dewatering dry-discharge and directly piles , landfills or transports outside the dried tailings .Upon application of this technology , the ore dressing enterprises will no longer need to build large concentra-tor, tailings dam, long distance pipeline transportation of tailings and tailings dam backwater , thus save valuable construc-tion site and infrastructure costs , and avoid environmental problems and safety concerns during the operation , and enhance the utilization of return water from only 70%~75%to more than 95%, with zero drainage , and bring huge economic and social benefits.Through summery to the application , a set of methods of dry tailings discharge treatment for tailings disposal work are discussed for references .%尾矿脱水干排新技术,就是将尾矿进行脱水,干尾矿可直接干堆、填埋或外运的新技术。运用此项技术后,选矿企业将不再建设大型浓密机、尾矿坝、尾矿长距离输送管线及尾矿坝回水长距离输送管线,为企业节约宝贵的建设场地及大量基建费用;避免了尾矿库运行期间破坏生态环境和安全隐患大等问题;将回水利用率由原来只有70%~75%左右提高到95%以上,且实现生产零排水,经济和社会效益巨大。本文通过对尾矿脱水筛在尾矿干排系统中的技术应用的总结,概括出尾矿干排处理的一套方法,以期和大家共同探讨学习,做好尾矿处理工作。

  18. Performance and techno-economic assessment of several solid-liquid separation technologies for processing dilute-acid pretreated corn stover.

    Science.gov (United States)

    Sievers, David A; Tao, Ling; Schell, Daniel J

    2014-09-01

    Solid-liquid separation of pretreated lignocellulosic biomass slurries is a critical unit operation employed in several different processes for production of fuels and chemicals. An effective separation process achieves good recovery of solute (sugars) and efficient dewatering of the biomass slurry. Dilute acid pretreated corn stover slurries were subjected to pressure and vacuum filtration and basket centrifugation to evaluate the technical and economic merits of these technologies. Experimental performance results were used to perform detailed process simulations and economic analysis using a 2000 tonne/day biorefinery model to determine differences between the various filtration methods and their process settings. The filtration processes were able to successfully separate pretreated slurries into liquor and solid fractions with estimated sugar recoveries of at least 95% using a cake washing process. A continuous vacuum belt filter produced the most favorable process economics.

  19. Development of Advanced Surface Enhancement Technology for Decreasing Wear and Corrosion of Equipment Used for Mineral Processing

    Energy Technology Data Exchange (ETDEWEB)

    Daniel Tao; Craig A. Blue

    2004-08-01

    Equipment wear is a major concern in the mineral processing industry, which dramatically increases the maintenance cost and adversely affects plant operation efficiency. In this research, wear problems of mineral processing equipment including screens, sieve bends, heavy media vessel, dewatering centrifuge, etc., were identified. A novel surface treatment technology, high density infrared (HDI) surface coating process was proposed for the surface enhancement of selected mineral processing equipment. Microstructural and mechanical properties of the coated samples were characterized. Laboratory-simulated wear tests were conducted to evaluate the tribological performance of the coated components. Test results indicate that the wear resistance of AISI 4140 and ASTM A36 steels can be increased 3 and 5 folds, respectively by the application of HDI coatings.

  20. Plant-wide (BSM2) evaluation of reject water treatment with a SHARON-Anammox process

    DEFF Research Database (Denmark)

    Volcke, Eveline; Gernaey, Krist; Vrecko, Darko;

    2006-01-01

    In wastewater treatment plants (WWTPs) equipped with sludge digestion and dewatering systems, the reject water originating from these facilities contributes significantly to the nitrogen load of the activated sludge tanks, to which it is typically recycled. In this paper, the impact of reject water...... streams on the performance of a WWTP is assessed in a simulation study, using the Benchmark Simulation Model no. 2 (BSM2), that includes the processes describing sludge treatment and in this way allows for plant-wide evaluation. Comparison of performance of a WWTP without reject water with a WWTP where...... treatment plant, reject water treatment with a combined SHARON-Anammox process seems a promising option. The simulation results indicate that significant improvements of the effluent quality of the main wastewater treatment plant can be realized. An economic evaluation of the different scenarios...

  1. Brine Dewatering Using Ultrasonic Nebulization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Recovery of water from brine is critically important for manned space exploration. Resupply of water is prohibitively costly for extended missions. It is anticipated...

  2. Brine Dewatering Using Ultrasonic Nebulization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Recovery of water from brine is critically important for future manned space exploration. Resupply of water is prohibitively costly for such extended missions. Water...

  3. 电石路线氯乙烯生产技术新进展%Recent technological progress in production of vinyl chloride by calcium carbide process

    Institute of Scientific and Technical Information of China (English)

    高旭东

    2011-01-01

    探讨了在电石法PVC生产中从电石生产、乙炔发生、乙炔清净、电石渣浆清液循环、电石渣浆中乙炔回收、乙炔脱水、氯乙烯合成一直到氯乙烯脱水干燥这一系列生产过程中的技术新进展情况,指出我国电石法PVC已不再是“低水平建设”。探讨了生产工艺中还须改进之处。%The recent technological progresses in the production of vinyl chloride by calcium carbide process, such as calcium carbide production, acetylene production, acetylene purification, recycling of calcium carbide sludge supernatant, recovery of acetylene in calcium carbide sludge, acetylene dewatering, vinyl chloride synthesis and vinyl chloride dewatering and drying, were reviewed. It was indicated that the technological level of calcium carbide method PVC production in China was no longer low. Some shortcomings of the production process were pointed out.

  4. Techno-economic feasibility of mine-mouth power and process steam generation in a CFBC using processing plant waste fuel

    Energy Technology Data Exchange (ETDEWEB)

    Chugh, Y.P.; Patwardhan, A. [Southern Illinois University-Carbondale, Carbondale, IL (USA). Department of Mining & Mineral Resources

    2002-07-01

    The techno-economic feasibility of mine-mouth power generation using processed fine coal refuse fuel has been evaluated. Fine coal processing studies were conducted on the -100 mesh fine coal refuse of a central Illinois coal mine. On-site column froth flotation testing using a 15-cm diameter (7 kg/hr) laboratory Jameson cell produced a 30,175 kJ/kg product at a combustible recovery of 75%. The sulfur content of this product was 2.85% with {le}30% sulfur being of pyritic origin and mean particle size was 60 microns. Dewatering studies were conducted on the flotation product using a pilot scale filter press. The dewatering tests produced a 21% total moisture content filter cake from a 27% solids slurry at 6-10 minute cycle times.Material handling tests involving pumpability of the fine coal fuel established the feasibility of pumping this fuel to a fluidized bed boiler. A hydraulically driven piston pump was chosen. Bench-scale combustion tests, conducted at Canadian Energy Technology Center, using a 100-mm diameter, 5 m high circulating fluidized bed combustor demonstrated the feasibility of achieving sustained combustion of the fine coal slurry containing up to 51% moisture content. Combustion efficiency in the range of 95-99.5% was achieved. Sulfur capture efficiency was in the range of 83.5% to 89.0% at Ca/S ratios of 2.16 and 2.39. NOx emission levels were low with only about 4 to 5% of fuel nitrogen converting to NOx. Though mercury emissions were low, further reductions can be anticipated in a full scale unit depending on the operating temperature of the baghouse. 13 refs., 10 figs., 4 tabs.

  5. 高分子絮凝剂对活性污泥脱水性能影响的比较%Research of Effects of Polymer Flocculants on Dewatering Performance of Activated Sludge

    Institute of Scientific and Technical Information of China (English)

    赵旭德; 陈龙; 吴琦芳

    2013-01-01

    This paper mainly researched the effects of different polymer flocculants on the residual sludge of urban sewage after being suction filtrated under different dosages while the flocculants were mainly PAC ,cat-ionic PAM ,anionic PAM and nonionic PAM .The main indexes were sludge specific resistance ,moisture con-tent,drying time.The results showed that all the flocculants could effectively reduce the sludge specific resist-ance and moisture content.When the dosage were in 90 ~110 mg· L -1 ,all the flocculants can meet the re-quirements that the moisture content decreased to 70%.Under the dosage of 50 ~100 mg· L -1 ,the effects of all the flocculants were similar .When the dosage were in 100 ~200 mg· L -1 ,the effects of cationic PAM was better than anionic,nonionic PAM and PAC.When the dosage were 100 mg· L -1,anionic,nonionic PAM and PAC obtained the best dewatering performance while that for cationic PAM was 150 mg·L -1.%为了比较用 PAC、阳离子PAM、阴离子 PAM 和非离子 PAM 作为絮凝剂,改善剩余污泥脱水性能的效果,分别使用不同投加量的以上5种絮凝剂,对城市污水厂剩余污泥进行真空过滤脱水,对比污泥比阻值、含水率、脱水时间的变化情况。结果表明:PAC、阳离子 PAM、阴离子 PAM 和非离子PAM 可有效降低污泥比阻和含水率,投加量在90~110 mg· L -1时可满足将含水率降至70%的要求。投加量在50~100 mg· L -1时,阳离子 PAM、阴离子PAM、非离子 PAM 和 PAC 的调理效果相近;投加量在100~200 mg· L -1时,阳离子 PAM 的调理效果优于阴离子 PAM、非离子 PAM 和 PAC;阴离子PAM、非离子PAM 和PAC 的投加量约为100 mg· L -1时脱水效果最好;阳离子 PAM 投加量约为150 mg· L -1时脱水效果最好。

  6. 脱水污泥厌氧发酵搅拌动力需求试验研究%Experimental Study on Power Requirements for Stirring in Dewatered Sludge Anaerobic Digestion

    Institute of Scientific and Technical Information of China (English)

    盛金良; 严敏东; 赵志永; 龚莹

    2012-01-01

    对于含固率较高的脱水污泥厌氧发酵系统,对物料的搅拌是能耗的重要组成部分,而目前对发酵工艺中机械搅拌动力需求的研究几乎没有.研制了一台卧式强制搅拌干式厌氧发酵反应器,对叶片搅拌过程进行受力分析,计算出理论搅拌扭矩,并以此反应器为基础,研究了污水处理厂脱水污泥的搅拌动力需求.具体研究了污泥的含固率、搅拌转速、反应器填充率等因素对搅拌动力需求的影响,发现低转速下,转速对搅拌扭矩影响非常小,而从搅拌动力需求角度考虑,物料填充率在66.7%~85%之间比较合理.同时还对长期连续搅拌状态下污泥所需的搅拌动力的变化做了研究,发现经过搅拌污泥的内摩擦角和粘聚力出现了较大的变化,从而引起搅拌所需动力在短时间内大幅降低.而原污泥兑水使含固率降低、自由水含量增加时,其搅拌动力需求呈指数趋势减小.%Stirring takes an essential part in energy consumption in an anaerobic digestion system of dewatered sludge with high solids, but little relative research about power requirements for stirring has been done. A horizontal continuous stirred tank reactor for high solids anaerobic digestion were built to study the influence of power requirement brought by sludge solids content, stirring speed and reactor fill level. Force analysis of mixing arms were done and theoretical torsion needs for stirring obtained. Experiments results indicated that changing stirring speed has little effect on power requirements, and the fill level kept between 66.7% and 85% is more reasonable from energy point of view. Some studies were done for dynamic change of power requirement in long-term continuous stirring, showing that the power needs for stirring decline rapidly due to the substantial changes in internal friction angle and cohesive force. The torsion requirements decrease exponentially by adding free water into the sludge.

  7. 接种菌剂和外加能源对污泥生物干化效果的影响%Effect of microbial inoculants and additional energy on bio-drying of dewatered sludge

    Institute of Scientific and Technical Information of China (English)

    余旺; 黄绍松; 孙水裕; 张小娟; 林伟雄; 陈港权; 许娉婷

    2012-01-01

    采用自主设计的试验装置,研究了接种菌剂和外加能源对城市污水处理厂脱水污泥生物干化效果的影响.结果表明:(1)试验7d,添加接种菌剂的物料升温累积值为66.0℃.d,比不添加接种菌剂(18.3℃.d)大261%;添加接种菌剂物料的水分去除率(27.33%)比不添加接种菌剂(18.56%)提高了8.77百分点;添加接种菌剂物料的挥发性固体(VS)降解率(20.90%)比不添加接种菌剂(12.31%)高8.59百分点;添加接种菌剂物料的减重率(18.67%)比不添加接种菌剂(10.80%)高7.87百分点.(2)试验8d,添加外加能源的升温累积值(69.5℃.d)比不加外加能源(46.2℃.d)大50.43%;添加外加能源物料的水分去除率(33.50%)比不加外加能源(28.56%)高4.94百分点;添加外加能源的物料VS降解率(22.62%)比不加外加能源(19.67%)高2.95百分点;添加外加能源物料的减重率(19.56%)比不加外加能源(17.87%)高1.69百分点.%Influences of microbial inoculants and additional energy on bio-drying of dewatered sludge were studied in self-designed experimental equipment. Results showed that after 7 days of experiment, the temperature cumulation (TO of microbial inoculated material reached to 66. 0 ℃ · d, which was 261% higher than that of no microbial inoculation materials (18. 3 ℃ · d). The moisture removal rate of microbial inoculation material was 27. 33%,which was 8. 77 percent higher than that of no microbial inoculation materials (18. 56%) ; VS degradation rate of microbial inoculation material was 20. 90%, which was 8. 59 percent higher than no microbial inoculation materials (12. 31%); weight loss rate of microbial inoculation materials was 18. 67% .which was 7. 87 percent higher than that of no microbial inoculation materials (10. 80%). Compared with groups of no additional energy,adding additional energy enhanced the TC of material by 50. 43% (from 46. 2 C · d to 69. 5 ℃ · d) after 8 days of experiment

  8. Solidification of dewatered sewage sludge using bottom ash of MSWI as skeleton material%以垃圾焚烧底灰为骨料的脱水污泥固化试验

    Institute of Scientific and Technical Information of China (English)

    陈萍; 冯彬; 詹良通

    2014-01-01

    Dehydrate sewage sludge is low in sheared strength, and its landfilling disposal has safety issues. Experimental study on the solidification of dewatered sewage sludge was carried out by using the bottom ash of municipal solid waste incinerator (MSWI) as skeleton material, and using cement, lime, gypsum as solidification materials. Unconfined compressive strength (UCS) tests, water resistance tests, and leaching test were performed to investigate the solidification effect. The experimental results demonstrated that the optimum solidification materials were cement and gypsum, and the optimum adding mixture ratio of dry mass of sewage sludge was 50%. Measured UCS of the solidified sludge met the requirement for safe landfilling. The optimum adding mixture ratio of MSWI bottom ash was 100%, which resulted in the volume change ratio being less than 1.0. The water resistance capacity of the sludge solidified by cement and gypsum was high. The leaching tests showed that gypsum was the optimum solidification material, the measured concentration of Cu, Zn, Pb and COD of the leachate was significantly lower than the untreated sludge. Furthermore, the pH of the leachate was close to 7.0. Leachate was low in toxicity, with minor effect on the environment.%针对机械脱水污泥强度低,难以安全填埋的问题,采用生活垃圾焚烧底灰作为骨架材料和水泥、石灰、石膏作为固化剂,开展污泥固化试验研究,并通过无侧限抗压强度试验、耐水性试验、浸出毒性试验对固化效果进行评价.结果表明,较优的固化剂种类为水泥和石膏,掺入量为污泥干基的50%,无侧限抗压强度可以满足填埋要求.最优垃圾焚烧底灰掺入量为100%,固化污泥增容比小于1.0,能够起到减容作用.水泥、石膏固化污泥耐水性能均较好.浸出毒性试验结果表明,最优固化剂种类为石膏,浸出液Cu、Zn、Pb离子浓度及COD值均较原泥大幅降低,可以起到良好的稳定

  9. Preparation of biochar from co-pyrolysis of dewatered sewage sludge-pine sawdust and its adsorption capability%脱水污泥-松木共热解生物炭的制备及吸附性能

    Institute of Scientific and Technical Information of China (English)

    成功; 孙蕾; 焦李; 肖波

    2013-01-01

    以脱水污泥(含水率80%)和松木的混合物为原料共热解制备生物炭.研究了松木掺混比、热解温度对生物炭产率和BET比表面积(SBET)的影响,采用元素分析、工业分析和扫描电镜比较了单独热解及共热解生物炭的元素组成和表面形貌.结果表明,生物炭产率随着松木掺混比的增加而提高,随着热解温度的升高而下降.2种原料共热解存在明显的协同效果:松木提高了生物炭的碳元素含量,污泥的水分具有一定的活化作用,生物炭表面粗糙程度增加、SBET扩大.当松木掺混比为60%、热解温度为750℃时,生物炭 SBET达到最高的213.4 m2/g.此外,生物炭对水中苯酚的吸附符合准二级动力学,等温吸附过程能用Freundlich模型描述.%Blends of dewatered sewage sludge(moisture content was 80%) and pine sawdust were used as feed stocks for biochar preparation from co-pyrolysis.The effects of blending ratio of pine sawdust and pyrolysis temperature on yield and SBET of biochar were studied; furthermore,the element composition and surface topography of biochars prepared from pyrolysis and co-pyrolysis were compared through ultimate analysis,proximate analysis and SEM.The results showed that,biochar yield increased with the increasing of pine sawdust while decreased with the increasing of pyrolysis temperature.A synergetic effect was found during the co-pyrolysis of the two feed stocks.As the addition of pine sawdust increased the carbon content of the biochar and the activating ability of the water in the sludge,the surface roughness and SBET of the biochar were increased.The maximal SBET reached 213.4 m2/g,which was obtained under the condition that the blending ratio of pine sawdust was 60% and the pyrolysis temperature was 750 ℃.Moreover,the adsorption of phenol by the biochar followed the pseudo second-order kinetics model and the adsorption isotherm could be described by Freundlich model.

  10. Sulfate digestion process for high purity TiO2 from titania slag

    Institute of Scientific and Technical Information of China (English)

    T. A. LASHEEN

    2009-01-01

    A titania slag product of Rosetta ilmenite assaying 72% Tio2 is treated by the sulfate process option of the pigmentary TiO2 manufacture. The relevant factors of acid concentration, particle size, slag/acid ratio besides the reaction temperature, and time have been studied. After dissolving the cured mass in dilute acid and clarification, the obtained solution was subjected to hydrolysis of its titanium content. The final product was bleached under reducing conditions to redissolve the residual coloring impurities before being dewatered and calcinated. The obtained results indicated that a leaching efficiency of about 92% was realized due to the presence of some refractory components in the working slag material, namely, rutile and magnesium iron titanate. The obtained white pigment assay attained up to 99.85% TiO2, while the analyzed impurities involve 77ppm Mn and only 14 and 7 ppm of total iron and V, respectively.

  11. Long-term performance of side-stream deammonification in a continuous flow granular-activated sludge process for nitrogen removal from high ammonium wastewater.

    Science.gov (United States)

    Rezania, Babak; Mavinic, Donald S; Kelly, Harlan G

    2015-01-01

    An innovative granular sludge deammonification system was incorporated into a conventional-activated sludge process. The process incorporated an internal baffle in the bioreactor for continuous separation of granular biomass from flocculent biomass, which allowed for controlling the solids retention time of flocculent sludge. The process was evaluated for ammonium removal from municipal digested sludge dewatering centrate under various operating conditions lasting over 450 days. The process successfully removed, on average, 90% of the ammonium from centrate at various ammonium loading reaching 1.4 kg/m³d at 20 hours hydraulic retention time. Controlling the retention time of the flocculent biomass and maintaining low nitrite concentration were both found to be effective for nitrite oxidizing bacteria management, resulting in a low nitrate concentration (below 50 mg/L) over a wide range of flocculent biomass concentration in the bioreactor.

  12. Microalgae harvesting and processing: a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Shelef, G.; Sukenik, A.; Green, M.

    1984-08-01

    The objective of this report is to present a discussion of the literature review performed on methods of harvesting microalgae. There is no single best method of harvesting microalgae. The choice of preferable harvesting technology depends on algae species, growth medium, algae production, end product, and production cost benefit. Algae size is an important factor since low-cost filtration procedures are presently applicable only for harvesting fairly large microalgae. Small microalgae should be flocculated into larger bodies that can be harvested by one of the methods mentioned above. However, the cells' mobility affects the flocculation process, and addition of nonresidual oxidants to stop the mobility should be considered to aid flocculation. The decision between sedimentation or flotation methods depends on the density difference between the algae cell and the growth medium. For oil-laden algae with low cell density, flotation technologies should be considered. Moreover, oxygen release from algae cells and oxygen supersaturation conditions in growth medium support the use of flotation methods. If high-quality algae are to be produced for human consumption, continuous harvesting by solid ejecting or nozzle-type disc centrifuges is recommended. These centrifuges can easily be cleaned and sterilized. They are suitable for all types of microalgae, but their high operating costs should be compared with the benefits from their use. Another basic criterion for selecting the suitable harvesting procedure is the final algae paste concentration required for the next process. Solids requirements up to 30% can be attained by established dewatering processes. For more concentrated solids, drying methods are required. The various systems for algae drying differ both in the extent of capital investment and the energy requirements. Selection of the drying method depends on the scale of operation and the use for which the dried product is intended.

  13. Lab-scale demonstration of recuperative thickening technology for enhanced biogas production and dewaterability in anaerobic digestion processes.

    Science.gov (United States)

    Cobbledick, Jeffrey; Aubry, Nicholas; Zhang, Victor; Rollings-Scattergood, Sasha; Latulippe, David R

    2016-05-15

    There is growing interest in the use of high performance anaerobic digestion (AD) processes for the production of biogas at wastewater treatment facilities to offset the energy demands associated with wastewater treatment. Recuperative thickening (RT) is a promising technique which involves recycling a portion of the digested solids back to the incoming feed. In general there exists a significant number of knowledge gaps in the field of RT because the studies that have been conducted to date have almost exclusively occurred in pilot plant or full scale trials; this approach greatly limits the amount of process optimization that can be done in a given trial. In this work, a detailed and comprehensive study of RT was conducted at the lab scale; two custom designed digesters (capacity = 1.5 L) were operated in parallel with one acting as a 'control' digester and the other operating under a semi-batch RT mode. There was no significant change in biogas methane composition for the two digesters, however the RT digester had an average biogas productivity over two times higher than the control one. It was found that the recycling of the polymer flocculant back into the RT digester resulted in a significant improvement in dewatering performance. At the highest polymer concentration tested, the capillary suction time (CST) values for flocculated samples for the RT digester were over 6 times lower than the corresponding values for the control digester. Thus, there exists an opportunity to decrease the overall consumption of polymer flocculants through judicious selection of the dose of polymer flocculant that is used both for the thickening and end-stage dewatering steps in RT processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Partnering for Discoverability: Knitting Archival Finding Aids to Digitized Material Using a Low Tech Digital Content Linking Process

    Directory of Open Access Journals (Sweden)

    Liz Woolcott

    2016-10-01

    Full Text Available As libraries continue to ramp up digitization efforts for unique archival and special collections material, the segregation of archival finding aids from their digitized counterparts presents an accumulating discoverability problem for both patrons and library staff. For Utah State University (USU Libraries, it became evident that a system was necessary to connect both new and legacy finding aids with their digitized content to improve use and discoverability. Following a cross-departmental workflow analysis involving the Special Collections, Cataloging and Metadata, and Digital Initiatives departments, a process was created for semi-automating the batch linking of item and folder level entries in EAD finding aids to the corresponding digitized material in CONTENTdm. In addition to the obvious benefit of linking content, this cross-departmental process also allowed for the implementation of persistent identifiers and the enhancement of finding aids using the more robust metadata that accompanies digitized material. This article will provide a detailed overview of the process, as well as describe how the three departments at USU have worked together to identify key stakeholders, develop the procedures, and address future developments.

  15. Educação à distância em processos de esterilização de materiais Educación a distancia en procesos de esterilización de materiales Long-distance learning on surgical material sterilization processes

    Directory of Open Access Journals (Sweden)

    Maria Cristina Ferreira Quelhas

    2008-12-01

    Full Text Available Este artigo descreve as etapas de desenvolvimento de um curso de educação à distância (EAD sobre Processos de Esterilização de Materiais, com o uso da Internet; sua avaliação por especialistas em processos de esterilização e em EAD; o perfil dos alunos e avaliadores; a participação dos alunos e sua opinião sobre o curso. O ambiente de aprendizagem escolhido foi o TelEduc. Utilizou-se a metodologia de ensino Aprendizagem Baseada em Casos (ABC. A população-alvo foi constituída por enfermeiros da Região Metropolitana de Campinas e cidades do Estado de São Paulo. Dos 58 enfermeiros convidados, 14 se inscreveram e 11 finalizaram o curso. O curso foi avaliado pelos juízes antes e após a sua aplicação. Um questionário do tipo Likert foi utilizado para avaliar a opinião dos alunos . A metodologia ABC favoreceu a participação dos alunos e o curso foi avaliado positivamente.Este artículo describe las etapas de desarrollo de un curso de educación a distancia (EAD sobre Procesos de Esterilización de Materiales utilizando Internet, su evaluación por especialistas en procesos de esterilización y en EAD, el perfil de los alumnos y evaluadores, la participación de alumnos y su opinión sobre el curso. El ambiente de aprendizaje escogido fue TelEduc. Se utilizó la metodología de enseñanza Aprendizaje Basada en Casos (ABC. La población objetivo constituida por enfermeros de la Región Metropolitana de Campinas y ciudades de São Paulo. De los 58 enfermeros invitados, 14 se inscribieron y 11 finalizaron el curso. El curso fue evaluado por jueces antes y posterior a su aplicación. Un cuestionario tipo Likert fue utilizado para evaluar la opinión de los alumnos. La metodología ABC favorece la participación de los alumnos y el curso fue evaluado como positivo.This study had the following goals: describing the development of a distance learning (DL course on Surgical Material Sterilization Processes, to be given over the

  16. Process Design and Economics for the Conversion of Algal Biomass to Biofuels: Algal Biomass Fractionation to Lipid- and Carbohydrate-Derived Fuel Products

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.; Kinchin, C.; Markham, J.; Tan, E.; Laurens, L.; Sexton, D.; Knorr, D.; Schoen, P.; Lukas, J.

    2014-09-01

    Beginning in 2013, NREL began transitioning from the singular focus on ethanol to a broad slate of products and conversion pathways, ultimately to establish similar benchmarking and targeting efforts. One of these pathways is the conversion of algal biomass to fuels via extraction of lipids (and potentially other components), termed the 'algal lipid upgrading' or ALU pathway. This report describes in detail one potential ALU approach based on a biochemical processing strategy to selectively recover and convert select algal biomass components to fuels, namely carbohydrates to ethanol and lipids to a renewable diesel blendstock (RDB) product. The overarching process design converts algal biomass delivered from upstream cultivation and dewatering (outside the present scope) to ethanol, RDB, and minor coproducts, using dilute-acid pretreatment, fermentation, lipid extraction, and hydrotreating.

  17. Inactivation of enteric bacterial pathogens in sewage sludge by anaerobic digestion and dewatering treatment%城市污泥厌氧消化和脱水工艺对肠道病原菌的杀灭效应效应

    Institute of Scientific and Technical Information of China (English)

    王燕; 符波; 陈燕; 姜谦; 陈坚; 刘和

    2012-01-01

    This study investigated the quantities of three enteric bacterial pathogens, E. coli, Salmonella spp. and Shigella spp. through anaerobic digestion and dewatering treatment by using the most probable number (MPN) culture and quantitative real-time PCR (qPCR) methods. MPN results showed that the quantities of E. coli, Salmonella spp. and Shigella spp. decreased significantly after anaerobic digestion, and the average log reduction values were 2 ~ 5. However, the qPCR results showed the average log reduction values were 1 -2. After dewatering treatment, the quantities of three pathogens in the sludge changed slightly and no phenomenon of regrowth after dewatering was observed. The concentrations of E. coil, Salmonella spp. and Shlgella spp. were between 104~107、104~105 , and 103 - 105 MPN.g-I (dry weight) , respectively. The detection difference between the MPN and qPCR results indicated the existence of viable but non-culturable (VBNC) pathogens which resulted from anaerobic digestion treatment. This phenomenon suggested that the application of traditional culture methods should be careful for the bacterial pathogens detection and the biological safety assessment in sewage sludge discharge%运用最大或然数(MPN)培养法和定量PCR(qPCR)技术对不同城市污水处理厂污泥厌氧消化处理和脱水处理前后,污泥中埃希氏大肠杆菌(E.coli)、沙门氏菌(Salmonellaspp.)和志贺氏菌(Shigellaspp.)含量的变化进行了研究.MPN检测结果表明,污泥中大肠杆菌、沙门氏菌和志贺氏菌数量经厌氧消化处理后明显下降,平均下降2~5个数量级,但qPCR检测结果显示,种病原菌平均下降1~2个数量级.脱水处理3后,污泥中的肠道病原菌含量基本没有变化,没有发生脱水后再生长现象.大肠杆菌、沙门氏菌和志贺氏菌含量分别在104~107、104~105和103~105MPN·g-1(以污泥干重计)之间.MPN和qPCR检测结果之间的差

  18. Integration Technology of Combining Binary-layer Foundation Excavation Dewatering with Suspended Cut-off Wall and Recharge%二元地基基坑降水结合悬挂式防渗墙及回灌一体化技术

    Institute of Scientific and Technical Information of China (English)

    王恒; 李守德; 王由国; 柯倩雯; 张灿虹

    2015-01-01

    In this paper,a generalized model of the typical cross-section is used to study the consequence of excavation dewatering with suspended cut-off wall and recharge well which have some effects on water head and ground subsidence which is outside of excavation. The comparisons of the condition of excavation direct precipitation , the condition of cut-off wall excavation precipitation and the condition of cut-off wall and recharge well excavation dewatering are analyzed. The result shows that suspended cut-off wall and recharge well can significantly enhance the water head and effectively reduce the settlement in the outside of the excavation,reduce the unit sedimentation of soft soil,have little effect on the unit sedimentation of silt and sand layers. Meanwhile,the comparisons of the tilt ratio of three conditions indicate the distance away from cut-off wall and recharge well closer ,the smaller the differential settlement.%通过构造基坑降水三维概化模型,利用有限元软件FLAC3D分析悬挂式防渗墙和回灌对基坑坑外的水头和地面沉降影响,主要将基坑直接降水工况、设置防渗墙的基坑降水工况和设置防渗墙及回灌井的基坑降水工况进行对比分析。分析结果表明防渗墙和回灌井,可明显提升坑外水头,有效降低了坑外沉降,减小软土层的单位沉降值,对粉砂层和细砂层的单位沉降值影响很小。同时,对比三种工况下的倾斜比,说明了距离防渗墙与回灌井越近,不均匀沉降越小。

  19. Evaluation of Brine Processing Technologies for Spacecraft Wastewater

    Science.gov (United States)

    Shaw, Hali L.; Flynn, Michael; Wisniewski, Richard; Lee, Jeffery; Jones, Harry; Delzeit, Lance; Shull, Sarah; Sargusingh, Miriam; Beeler, David; Howard, Jeanie; Howard, Kevin; Harris, Linden; Parodi, Jurek; Kawashima, Brian

    2015-01-01

    Brine drying systems may be used in spaceflight. There are several advantages to using brine processing technologies for long-duration human missions including a reduction in resupply requirements and achieving high water recovery ratios. The objective of this project was to evaluate four technologies for the drying of spacecraft water recycling system brine byproducts. The technologies tested were NASA's Forward Osmosis Brine Drying (FOBD), Paragon's Ionomer Water Processor (IWP), NASA's Brine Evaporation Bag (BEB) System, and UMPQUA's Ultrasonic Brine Dewatering System (UBDS). The purpose of this work was to evaluate the hardware using feed streams composed of brines similar to those generated on board the International Space Station (ISS) and future exploration missions. The brine formulations used for testing were the ISS Alternate Pretreatment and Solution 2 (Alt Pretreat). The brines were generated using the Wiped-film Rotating-disk (WFRD) evaporator, which is a vapor compression distillation system that is used to simulate the function of the ISS Urine Processor Assembly (UPA). Each system was evaluated based on the results from testing and Equivalent System Mass (ESM) calculations. A Quality Function Deployment (QFD) matrix was also developed as a method to compare the different technologies based on customer and engineering requirements.

  20. An overview of mineral dust modeling over East Asia

    Science.gov (United States)

    Chen, Siyu; Huang, Jianping; Qian, Yun; Zhao, Chun; Kang, Litai; Yang, Ben; Wang, Yong; Liu, Yuzhi; Yuan, Tiangang; Wang, Tianhe; Ma, Xiaojun; Zhang, Guolong

    2017-08-01

    East Asian dust (EAD) exerts considerable impacts on the energy balance and climate/climate change of the earth system through its influence on solar and terrestrial radiation, cloud properties, and precipitation efficiency. Providing an accurate description of the life cycle and climate effects of EAD is therefore critical to better understanding of climate change and socioeconomic development in East Asia and even worldwide. Dust modeling has undergone substantial development since the late 1990s, associated with improved understanding of the role of EAD in the earth system. Here, we review the achievements and progress made in recent decades in terms of dust modeling research, including dust emissions, long-range transport, radiative forcing (RF), and climate effects of dust particles over East Asia. Numerous efforts in dust/EAD modeling have been directed towards furnishing more sophisticated physical and chemical processes into the models on higher spatial resolutions. Meanwhile, more systematic observations and more advanced retrieval methods for instruments that address EAD related science issues have made it possible to evaluate model results and quantify the role of EAD in the earth system, and to further reduce the uncertainties in EAD simulations. Though much progress has been made, large discrepancies and knowledge gaps still exist among EAD simulations. The deficiencies and limitations that pertain to the performance of the EAD simulations referred to in the present study are also discussed.

  1. A Decontamination Process to Remove Metals and Stabilise Montreal Sewage Sludge

    Directory of Open Access Journals (Sweden)

    G. Mercier

    2002-01-01

    Full Text Available The Montreal Urban Community (MUC treatment plant produces approximately 270 tons of dry sludge daily (tds/day during physicochemical wastewater treatment. The sludges are burned and contribute to the greenhouse effect by producing atmospheric CO2. Moreover, the sludge emanates a nauseating odour during its thermal stabilisation and retains unpleasant odours for the part (25% that is dried and granulated. To solve this particular problem, the treatment plant authorities are currently evaluating an acidic chemical leaching (sulfuric or hydrochloric acid process at a pH between 2 and 3, using an oxidizing agent such as ferric chloride or hydrogen peroxide (METIX-AC technology, patent pending; [20]. They could integrate it to a 70 tds/day granulated sludge production process. Verification of the application of METIX-AC technology was carried out in a pilot plant set up near the sludge production plant of the MUC. The tests showed that METIX-AC technology can be advantageously integrated to the process used at the MUC. The residual copper (274 ± 58 mg/kg and cadmium (5.6 ± 2.9 mg/kg concentrations in the treated sludge meet legislation standards. The results have also shown that odours have been significantly eliminated for the dewatered, decontaminated, and stabilized biosolids (> 97% compared to the non-decontaminated biosolids. A high rate of odour elimination also was obtained for the liquid leached biosolids (> 93%, compared to the untreated liquid biosolids. The fertilising value (N and P is well preserved by the METIX-AC process. Dissolved organic carbon measurements have showed that little organic matter is brought in solution during the treatment. In fact, the average concentration of dissolved organic carbon measured in the treated liquid phase is 966 ± 352 mg/l, whereas it is 1190 ± 325 mg/l in untreated sludge. The treated sludge was first conditioned with an organic polymer and a coagulant aid. It was successfully dewatered with

  2. BACTERIOPHAGE ENDOLYSINS AND THEIR USE IN BIOTECHNOLOGICAL PROCESSES

    Directory of Open Access Journals (Sweden)

    Lenka Tišáková

    2014-02-01

    Full Text Available Bacteriophage endolysins are peptidoglycan hydrolases, produced in the lytic system of bacteriophage in order to lyse host peptidoglycan from within and release virions into the environment. Phages infecting Gram-positive bacteria express endolysin genes with the characteristic modular structure, consisting of at least two functional domains: N-terminal enzymatically active domain (EAD and C-terminal cell wall binding domain (CBD. CBDs specifically recognize ligands and bind to the bacterial cell wall, whereas EAD catalyze lysis of the peptidoglycan bonds. The reveal of endolysin modular structure leads to new opportunities for domain swapping, construction of chimeras and production of specifically engineered recombinant endolysins and their functional domains with the diverse biotechnological applications from without, such as in detection, elimination and biocontrol of pathogens, or as anti-bacterials in experimental therapy.

  3. Multi-step process for concentrating magnetic particles in waste sludges

    Science.gov (United States)

    Watson, John L.

    1990-01-01

    This invention involves a multi-step, multi-force process for dewatering sludges which have high concentrations of magnetic particles, such as waste sludges generated during steelmaking. This series of processing steps involves (1) mixing a chemical flocculating agent with the sludge; (2) allowing the particles to aggregate under non-turbulent conditions; (3) subjecting the mixture to a magnetic field which will pull the magnetic aggregates in a selected direction, causing them to form a compacted sludge; (4) preferably, decanting the clarified liquid from the compacted sludge; and (5) using filtration to convert the compacted sludge into a cake having a very high solids content. Steps 2 and 3 should be performed simultaneously. This reduces the treatment time and increases the extent of flocculation and the effectiveness of the process. As partially formed aggregates with active flocculating groups are pulled through the mixture by the magnetic field, they will contact other particles and form larger aggregates. This process can increase the solids concentration of steelmaking sludges in an efficient and economic manner, thereby accomplishing either of two goals: (a) it can convert hazardous wastes into economic resources for recycling as furnace feed material, or (b) it can dramatically reduce the volume of waste material which must be disposed.

  4. Combinatorial life cycle assessment to inform process design of industrial production of algal biodiesel.

    Science.gov (United States)

    Brentner, Laura B; Eckelman, Matthew J; Zimmerman, Julie B

    2011-08-15

    The use of algae as a feedstock for biodiesel production is a rapidly growing industry, in the United States and globally. A life cycle assessment (LCA) is presented that compares various methods, either proposed or under development, for algal biodiesel to inform the most promising pathways for sustainable full-scale production. For this analysis, the system is divided into five distinct process steps: (1) microalgae cultivation, (2) harvesting and/or dewatering, (3) lipid extraction, (4) conversion (transesterification) into biodiesel, and (5) byproduct management. A number of technology options are considered for each process step and various technology combinations are assessed for their life cycle environmental impacts. The optimal option for each process step is selected yielding a best case scenario, comprised of a flat panel enclosed photobioreactor and direct transesterification of algal cells with supercritical methanol. For a functional unit of 10 GJ biodiesel, the best case production system yields a cumulative energy demand savings of more than 65 GJ, reduces water consumption by 585 m(3) and decreases greenhouse gas emissions by 86% compared to a base case scenario typical of early industrial practices, highlighting the importance of technological innovation in algae processing and providing guidance on promising production pathways.

  5. Conditions for instant electrical stunning of farmed Atlantic cod after de-watering, maintenance of unconsciousness, effects of stress, and fillet quality — A comparison with AQUI-S™

    NARCIS (Netherlands)

    Erikson, U.; Lambooij, E.; Digre, H.; Reimert, H.G.M.; Bondø, M.; Vis, van de H.

    2012-01-01

    Electrical stunning of farmed Atlantic cod is a method used to render the fish unconscious before further processing. However, evaluations of the stunning method at plants have shown that the electrical parameters need to be optimized to achieve instant stunning and prolonged duration of unconscious

  6. Evaluate, Analyze, Describe (EAD): Confronting Underlying Issues of Racism and Other Prejudices for Effective Intercultural Communication

    OpenAIRE

    Daniel Velasco

    2015-01-01

    Racism and other prejudices have hindered efforts to diversify and further many fields, including education, psychology, politics, law, and healthcare (Race for Opportunity, 2010). Although there are many ways to combat these prejudices, intercultural communication continues to be a vital component in assisting individuals and groups with valuing the past, understanding the present, and preparing for the future of communication in a global society (Sadri and Flammia, 2011, p. 1...

  7. EAD no Brasil: perspectivas e desafios Distance education in Brazil: perspectives and challenges

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Gomes

    2013-03-01

    Full Text Available O presente trabalho discute alguns aspectos relativos à presença das tecnologias no Ensino Superior, começando pelo que chamamos, no Brasil, de Educação a Distância, com especial destaque para a criação do Sistema UAB- Universidade Aberta do Brasil e o contexto de sua criação. Salientamos que o projeto UAB apresenta certas incoerências em termos de legislação e também de propósitos e que, até agora, não se notam avanços pedagógicos marcantes nessa modalidade, cujos interesses tem se pautado na busca na transposição de práticas do ensino presencial. Argumentamos que a presença das tecnologias atuais de informação e de comunicação no cotidiano educacional, tanto no ensino presencial quanto no a distância deve ser transformadora, pois ela potencializa e pressupõe um outro paradigma educacional, que passa pela descentralização do currículo, do empoderamento dos alunos e da presença forte das comunidades de aprendizagem e das redes de relacionamento.This paper discusses some aspects regarding the presence of technology in higher education, starting with what we call in Brazil Distance Education, with particular emphasis on the creation of the UAB - Open University of Brazil and the context of its creation. We emphasize that the project UAB presents certain inconsistencies in legislation and also of purposes and that, so far, it has shown no major pedagogical advancements, having pursued especially the implementation of classroom practices. We argue that the presence of current technologies of information and communication in everyday life, especially in education and pedagogical tasks, including classroom teaching, should be transformative because it assumes a new kind of education, with the possibility of descentralizing the curriculum, empowering students and making use of the presence of strong learning communities and networks of relationship.

  8. Evaluate, Analyze, Describe (EAD): Confronting Underlying Issues of Racism and Other Prejudices for Effective Intercultural Communication

    Science.gov (United States)

    Velasco, Daniel

    2015-01-01

    Racism and other prejudices have hindered efforts to diversify and further many fields, including education, psychology, politics, law, and healthcare (Race for Opportunity, 2010). Although there are many ways to combat these prejudices, intercultural communication continues to be a vital component in assisting individuals and groups with valuing…

  9. Focal and Reentrant Mechanisms of Torsades de Pointes: EAD, Reentry, or Chimera?

    Directory of Open Access Journals (Sweden)

    Yuji Murakawa, MD

    2011-01-01

    Full Text Available Torsades de pointes (TdP. is characterized not only by its electrocardiographic morphology but also by a tendency to spontaneously terminate. Although clinical and experimental studies suggested that TdP is triggered exclusively by early afterdepolarization, the reentrant mechanism seems to play a certain role in its maintenance. In this article, I review the studies that investigated the origin and activation sequences of the twisting QRS complexes of TdP, and discuss whether it is fortunate or unfortunate for us if TdP has something to do with reentry.

  10. Ongoing Capabilities and Developments of Re-Entry Plasma Ground Tests at EADS-ASTRIUM

    Science.gov (United States)

    Jullien, Pierre

    2008-01-01

    During re-entry, spacecrafts are subjected to extreme thermal loads. On mars, they may go through dust storms. These external heat loads are leading the design of re-entry vehicles or are affecting it for spacecraft facing solid propellant jet stream. Sizing the Thermal Protection System require a good knowledge of such solicitations and means to model and reproduce them on earth. Through its work on European projects, ASTRIUM has developed the full range of competences to deal with such issues. For instance, we have designed and tested the heat-shield of the Huygens probe which landed on Titan. In particular, our plasma generators aim to reproduce a wide variety of re-entry conditions. Heat loads are generated by the huge speed of the probes. Such conditions cannot be fully reproduced. Ground tests focus on reproducing local aerothermal loads by using slower but hotter flows. Our inductive plasma torch enables to test little samples at low TRL. Amongst the arc-jets, one was design to test architecture design of ISS crew return system and others fit more severe re-entry such as sample returns or Venus re-entry. The last developments aimed in testing samples in seeded flows. First step was to design and test the seeding device. Special diagnostics characterizing the resulting flow enabled us to fit it to the requirements.

  11. Effective access to digital assets: An XML-based EAD search system

    NARCIS (Netherlands)

    Zhang, J.; Fachry, K.N.; Kamps, J.; Tibbo, H.R.; Hank, C.; Lee, C.A.; Clemens, R.

    2009-01-01

    This paper focuses on the question of effective access methods, by developing novel search tools that will be crucial on the massive scale of digital asset repositories. We illustrate concretely why XML matters in digital curation by describing an implementation of a baseline digital asset search sy

  12. EnvironmEntal and occupational ExposurE to lEad

    African Journals Online (AJOL)

    2008-06-06

    Jun 6, 2008 ... Jua kali) was 22.6 ± 13.4µg/dl. among the workers, 89% had Blls above 10µg/dl. in general, ... permanent brain damage due to lead poisoning. ... whiskies and from water whose delivery system is mainly made up of leaded pipes (1,6). occupationally, ... general clinical use and public health surveillance.

  13. Plataforma Blackboard: treinamento dos professores para a eficácia na EaD

    Directory of Open Access Journals (Sweden)

    Daniel Serravalle de Sá

    2010-08-01

    Full Text Available http://dx.doi.org/10.5007/1807-9288.2010v6n1p124 O presente artigo faz considerações sobre o uso da plataforma Blackboard Academic Suite como ferramenta de ensino no âmbito do Departamento de Espanhol, Português e Estudos Latino-Americanos (SPLAS na Universidade de Manchester. O que se oferece é um depoimento da experiência do autor enquanto um professor-usuário dessa tecnologia aplicada ao ensino. Reflete-se aqui sobre as funcionalidades da plataforma e a questão do treinamento necessário para utilização plena do programa e o sucesso da experiência educativa.

  14. Process Accounting

    OpenAIRE

    Gilbertson, Keith

    2002-01-01

    Standard utilities can help you collect and interpret your Linux system's process accounting data. Describes the uses of process accounting, standard process accounting commands, and example code that makes use of process accounting utilities.

  15. An Improved Process for Precipitating Cyanide Ions from the Barren Solution at Different pHs

    Science.gov (United States)

    Figueroa, Gabriela V.; Parga, José R.; Valenzuela, Jesus L.; Vázquez, Victor; Valenzuela, Alejandro; Rodriguez, Mario

    2016-02-01

    In recent decades, the use of metal sulfides instead of hydroxide precipitation in hydrometallurgical processes has gained prominence. Some arguments for its preferential use are as follows: a high degree of metal removal at relatively low pH values, the sparingly soluble nature of sulfide precipitates, favorable dewatering characteristics, and the stability of the formed metal sulfides. The Merrill-Crowe zinc-precipitation process has been applied worldwide in a large number of operations for the recovery of gold and silver from cyanide solutions. However, in some larger plants, the quality of this precious precipitate is low because copper, zinc and especially lead are precipitated along with gold and silver. This results in higher consumption of zinc dust and flux during the smelting of the precipitate, the formation of the matte, and a shorter crucible life. The results show that pH has a significant effect on the removal efficiency of zinc and copper cyanide ions. The optimal pH range was determined to be 3-4, and the removal efficiency of zinc and copper cyanide ions was up to 99%.

  16. Use of Anion Exchange Resins for One-Step Processing of Algae from Harvest to Biofuel

    Directory of Open Access Journals (Sweden)

    Martin Poenie

    2012-07-01

    Full Text Available Some microalgae are particularly attractive as a renewable feedstock for biodiesel production due to their rapid growth, high content of triacylglycerols, and ability to be grown on non-arable land. Unfortunately, obtaining oil from algae is currently cost prohibitive in part due to the need to pump and process large volumes of dilute algal suspensions. In an effort to circumvent this problem, we have explored the use of anion exchange resins for simplifying the processing of algae to biofuel. Anion exchange resins can bind and accumulate the algal cells out of suspension to form a dewatered concentrate. Treatment of the resin-bound algae with sulfuric acid/methanol elutes the algae and regenerates the resin while converting algal lipids to biodiesel. Hydrophobic polymers can remove biodiesel from the sulfuric acid/methanol, allowing the transesterification reagent to be reused. We show that in situ transesterification of algal lipids can efficiently convert algal lipids to fatty acid methyl esters while allowing the resin and transesterification reagent to be recycled numerous times without loss of effectiveness.

  17. Experimental study of the bio-oil production from sewage sludge by supercritical conversion process.

    Science.gov (United States)

    Wang, Yan; Chen, Guanyi; Li, Yanbin; Yan, Beibei; Pan, Donghui

    2013-11-01

    Environment-friendly treatment of sewage sludge has become tremendously important. Conversion of sewage sludge into energy products by environment-friendly conversion process, with its energy recovery and environmental benefits, is being paid significant attention. Direct liquefaction of sewage sludge into bio-oils with supercritical water (SCW) was therefore put forward in this study, as de-water usually requiring intensive energy input is not necessary in this direct liquefaction. Supercritical water may act as a strong solvent and also a reactant, as well as catalyst promoting reaction process. Experiments were carried out in a self designed high-pressure reaction system with varying operating conditions. Through orthogonal experiments, it was found that temperature and residence time dominated on bio-oil yield compared with other operating parameters. Temperature from 350 to 500°C and reaction residence time of 0, 30, 60min were accordingly investigated in details, respectively. Under supercritical conversion, the maximum bio-oil yield could achieve 39.73%, which was performed at 375°C and 0min reaction residence time. Meanwhile, function of supercritical water was concluded. Fuel property analysis showed the potential of bio-oil application as crude fuel.

  18. Interferon-γ, interleukin-10 and interferon-inducible protein 10 (CXCL10) as serum biomarkers for the early allograft dysfunction after liver transplantation.

    Science.gov (United States)

    Karakhanova, Svetlana; Oweira, Hani; Steinmeyer, Beate; Sachsenmaier, Milena; Jung, Gregor; Elhadedy, Hazem; Schmidt, Jan; Hartwig, Werner; Bazhin, Alexandr V; Werner, Jens

    2016-02-01

    Orthotopic liver transplantation (LTP) is nowadays a standard procedure, and provides the chance of survival of patients with end-stage non-treatable chronic liver disease or acute liver failure. Despite long-term survival with a good quality of life in the majority of patients, about 20% develop early allograft dysfunction (EAD), which leads to death or the need for re-transplantation. Therefore, the early diagnosis of EAD and evaluation of its risk factors are very important. Many primary pathological processes leading to EAD are accompanied by the release of different mediators and by a change of biochemical parameters detectable in the peripheral blood. The aim of this study was to investigate cytokines as well as soluble mediators in the serum of patients with and without EAD from our LTP bank, and to evaluate their predictive and prognostic values for EAD. We demonstrated for the first time that the level of IFNγ during the nearest preoperative period may serve as a predictive parameter for EAD. We additionally found that IL-10 and CXCL10 (IP-10) levels in the early postoperative period can be prognostic for EAD. We believe our data expand the spectrum of predictive and prognostic parameters for EAD in LTP. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. EXPERIMENTAL RESEARCH ON SATURATED MUCKY FOUNDATION TREATMENT WITH WELL-POINT DEWATERING COMBINED WITH DYNAMIC COMPACTION METHOD%井点降水联合强夯法加固饱和淤泥质地基的试验研究

    Institute of Scientific and Technical Information of China (English)

    刘嘉; 罗彦; 张功新; 董志良; 王友元

    2009-01-01

    针对传统强夯法不适用于高地下水位条件下加固饱和淤泥质黏土地基的不足,提出井点降水联合强夯新型静-动力排水固结技术与施工工艺,并结合广州港南沙港区粮食及通用码头工程软基处理试验区科研项目,通过对地下水位、孔隙水压力和表层沉降等实施现场监测及室内土工试验,分析其加固机制,进而验证施工参数.地基处理后,经静力触探试验、十字板剪切试验、标准贯入试验和静载荷板试验检测,证明加固效果显著,比贯入阻力提高200~300 kPa,标贯击数增加2击,地基承载力达130 kPa.研究工作为今后软基处理工程提供一种新的方法和思路.%Aiming at the insufficiency of traditional dynamic compaction method to saturated mucky with a high groundwater level,a new static-dynamic drainage consolidation technique,well-point dewatering combined with dynamic compaction method(WDDC) is developed. WDDC has been applied to Guangzhou Nansha harbor grain and universal terminal project soft foundation improvement test area research project where the in-situ monitoring (groundwater level,pore water pressure and settlement) and geotechnical laboratory tests are conducted to investigate the mechanism and qualification of WDDC. The ground treatment effect is confirmed by static cone penetration test,vane shear test,standard penetration test and static loading test. The specific penetration resistance can increase 200 to 300 kPa while the standard penetration test can be added 2 blows. The bearing capacity of foundation can reach 130 kPa. WDDC is an efficient soft foundation treatment method and the tests provide a new way for future industrial applications.

  20. Meat Processing.

    Science.gov (United States)

    Legacy, Jim; And Others

    This publication provides an introduction to meat processing for adult students in vocational and technical education programs. Organized in four chapters, the booklet provides a brief overview of the meat processing industry and the techniques of meat processing and butchering. The first chapter introduces the meat processing industry and…

  1. Primary Processing

    NARCIS (Netherlands)

    Mulder, W.J.; Harmsen, P.F.H.; Sanders, J.P.M.; Carre, P.; Kamm, B.; Schoenicke, P.

    2012-01-01

    Primary processing of oil-containing material involves pre-treatment processes, oil recovery processes and the extraction and valorisation of valuable compounds from waste streams. Pre-treatment processes, e.g. thermal, enzymatic, electrical and radio frequency, have an important effect on the oil r

  2. Removal of Nitrogen and Phosphorus From Reject Water Using Chlorella vulgaris Algae After Partial Nitrification/Anammox Process.

    Science.gov (United States)

    Gutwinski, Piotr; Cema, Grzegorz

    2016-01-01

    Wastewater containing nutrients like ammonia, nitrite, nitrate and phosphates have been identified as the main cause of eutrophication in natural waters. Therefore, a suitable treatment is needed. In classical biological processes, nitrogen and phosphorus removal is expensive, especially due to the lack of biodegradable carbon, thus new methods are investigated. In this paper, the new possibility of nitrogen and phosphorus removal in side stream after the partial nitrification/Anammox process is proposed. Research was carried out in a lab-scale vertical tubular photobioreactor (VTR) fed with real reject water, from dewatering of digested sludge, after partial nitrification/Anammox process from lab-scale sequencing batch reactor (SBR). Nitrogen and phosphorus concentrations were measured every three days. The average nitrogen and phosphorus loads were 0.0503 ± 0.036 g N g(vss)/d and 0.0389 ± 0.013 g P g(vss)/d accordingly. Results have shown that microalgae were able to efficiently remove nitrogen and phosphorus. The average nitrogen removal was 36.46% and phosphorus removal efficiency varied between 93 and 100%.

  3. Application of Hydrothermal Treatment to High Concentrated Sewage Sludge for Anaerobic Digestion Process

    Directory of Open Access Journals (Sweden)

    M. Orikawa

    2013-10-01

    Full Text Available Tomato and seaweed were produced by utilizing CO2 and heat discharged from power generation using biogas in Toyogawa biomass park, Japan. The biogas was obtained by anaerobic digestion with hydrothermal treatment. The hydrothermal treatment was applied to the high concentrated sewage sludge (22 % total solids (TS dewatered sludge. The purpose of this study is to clarify the effect of hydrothermal treatment on the qualities of high concentrated sewage sludge, by analyzing particulate organic carbon (POC and dissolved organic carbon (DOC. The hydrothermal treatment was investigated under 10-60 min of treatment time, 180-200 °C of temperature, 10-22 %-TS of sewage sludge concentration. The results showed that the DOC in each conditions increased through hydrothermal treatment. The highest DOC obtained was 67 % of total carbon concentration, when the temperature was 180 °C, treatment time was 60 min and sewage sludge concentration was 10 %-TS. Furthermore, the viscosity of treated sewage sludge was decreased by hydrothermal treatment. In batch anaerobic digestion test, methane gas production was confirmed. In addition, this study evaluated the energy balance of this system. Thus, the results of this study indicated that the possibility of application of hydrothermal treatment to high concentrated sewage sludge for anaerobic digestion process. Keywords: anaerobic reaction, hydrothermal treatment, sewage sludge, solubilization

  4. Methods to recover value-added coproducts from dry grind processing of grains into fuel ethanol.

    Science.gov (United States)

    Liu, Keshun; Barrows, Frederic T

    2013-07-31

    Three methods are described to fractionate condensed distillers solubles (CDS) into several new coproducts, including a protein-mineral fraction and a glycerol fraction by a chemical method; a protein fraction, an oil fraction and a glycerol-mineral fraction by a physical method; or a protein fraction, an oil fraction, a mineral fraction, and a glycerol fraction by a physicochemical method. Processing factors (ethanol concentration and centrifuge force) were also investigated. Results show that the three methods separated CDS into different fractions, with each fraction enriched with one or more of the five components (protein, oil, ash, glycerol and other carbohydrates) and thus having different targeted end uses. Furthermore, because glycerol, a hygroscopic substance, was mostly shifted to the glycerol or glycerol-mineral fraction, the other fractions had much faster moisture reduction rates than CDS upon drying in a forced air oven at 60 °C. Thus, these methods could effectively solve the dewatering problem of CDS, allowing elimination of the current industrial practice of blending distiller wet grains with CDS for drying together and production of distiller dried grains as a standalone coproduct in addition to a few new fractions.

  5. Characteristics of Non2uniformity and Vulnerability of Aquifers to Dewatering of Bedrock Fissure Water in the Hilly Area of the Taihang Mountains Piedmont%太行山前丘陵区基岩裂隙水赋存的非均一性和易疏干性特征

    Institute of Scientific and Technical Information of China (English)

    张光辉; 严明疆; 刘春华; 冯慧敏; 王金哲

    2013-01-01

    In terms of the issues of sustainable utilization of groundw ater in the hil y area of the Taihang mountains piedmont, the characteristics of non2uniformity and vulnerability of the aquifers to dew atering in the area w ere investigated based on the quan2 titative comparison analysis of the pumping and recovery test data from the deep bedrock fissure groundwat er w ells. The re2 search results showed t hat the spatial non2uniformity exists not only in the groundwater storage betw een different w ells, but al2 so in different dept hs of t he same well. For the pumping t ime less than 70 minutes, t he drawdow n of groundwater level in the well ZKs23 was larger than that in t he well Zks22. However, after 70 minutes of pumping, the draw down of groundw ater level in the w el ZKs22 w as larger than that in the w ell ZKs23, and the drawdow n difference betw een t he tw o w el s increased gradually wit h the increasing pumping time. These results indicated that the upper aquifer of w el ZKs22 has more w ater than the low er aquifer of well ZKs22, while the upper aquifer of w ell ZKs23 has less w ater than the lower aquifer of w el ZKs23. T he aquifer systems in different w el s had different vulnerability of groundwater to dewatering. With the increasing of pumping time, the maximum draw down and the time for recovery of groundwater level in the w ell ZKs22 increased, but the groundw ater level can be ful y restored to the initial level. H ow ever, the groundw ater level cannot recover to the initial level in the w el ZKs23, and the difference between the recovered groundw ater level and initial level increased as well, but the recovery t ime of groundwater level to a stable level w ere similar for different pumping t ests. Therefore, the reasonable design and layout of w el s is important to prevent the aquifers to dewatering in t he hilly area.%  针对太行山东簏丘陵区地下水能否可持续开发利用问题,基于探采结合的大量深井抽水及

  6. Elektrokemiske Processer

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers

    1997-01-01

    Electrochemical processes in: Power sources, Electrosynthesis, Corrosion.Pourbaix-diagrams.Decontamination of industrial waste water for heavy metals.......Electrochemical processes in: Power sources, Electrosynthesis, Corrosion.Pourbaix-diagrams.Decontamination of industrial waste water for heavy metals....

  7. Data processing

    CERN Document Server

    Fry, T F

    2013-01-01

    Data Processing discusses the principles, practices, and associated tools in data processing. The book is comprised of 17 chapters that are organized into three parts. The first part covers the characteristics, systems, and methods of data processing. Part 2 deals with the data processing practice; this part discusses the data input, output, and storage. The last part discusses topics related to systems and software in data processing, which include checks and controls, computer language and programs, and program elements and structures. The text will be useful to practitioners of computer-rel

  8. Process mining

    DEFF Research Database (Denmark)

    van der Aalst, W.M.P.; Rubin, V.; Verbeek, H.M.W.

    2010-01-01

    Process mining includes the automated discovery of processes from event logs. Based on observed events (e.g., activities being executed or messages being exchanged) a process model is constructed. One of the essential problems in process mining is that one cannot assume to have seen all possible...... behavior. At best, one has seen a representative subset. Therefore, classical synthesis techniques are not suitable as they aim at finding a model that is able to exactly reproduce the log. Existing process mining techniques try to avoid such “overfitting” by generalizing the model to allow for more...

  9. Relationship of shale dewatering and smectite dehydration to undercompaction occurrence

    Energy Technology Data Exchange (ETDEWEB)

    Leftwich, J.T. Jr.

    1996-12-01

    The cause(s) of abnormal fluid pressures in sedimentary basins are not clearly understood. One step in determining the mechanism(s) of abnormal pressure generation in sedimentary basins is to develop an understanding of the relationship among undercompacted shale, abnormal pressure, and temperature. Our research focused on understanding undercompaction and how it related to smectite-illite conversion. A series of carefully designed experiments were used to help clarify and evaluate the relationship of smectite-illite transformation to undercompaction.

  10. Method of waste stabilization with dewatered chemically bonded phosphate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Wagh, Arun; Maloney, Martin D.

    2010-06-29

    A method of stabilizing a waste in a chemically bonded phosphate ceramic (CBPC). The method consists of preparing a slurry including the waste, water, an oxide binder, and a phosphate binder. The slurry is then allowed to cure to a solid, hydrated CBPC matrix. Next, bound water within the solid, hydrated CBPC matrix is removed. Typically, the bound water is removed by applying heat to the cured CBPC matrix. Preferably, the quantity of heat applied to the cured CBPC matrix is sufficient to drive off water bound within the hydrated CBPC matrix, but not to volatalize other non-water components of the matrix, such as metals and radioactive components. Typically, a temperature range of between 100.degree. C.-200.degree. C. will be sufficient. In another embodiment of the invention wherein the waste and water have been mixed prior to the preparation of the slurry, a select amount of water may be evaporated from the waste and water mixture prior to preparation of the slurry. Another aspect of the invention is a direct anyhydrous CBPC fabrication method wherein water is removed from the slurry by heating and mixing the slurry while allowing the slurry to cure. Additional aspects of the invention are ceramic matrix waste forms prepared by the methods disclosed above.

  11. Method of waste stabilization with dewatered chemically bonded phosphate ceramics

    Science.gov (United States)

    Wagh, Arun; Maloney, Martin D.

    2010-06-29

    A method of stabilizing a waste in a chemically bonded phosphate ceramic (CBPC). The method consists of preparing a slurry including the waste, water, an oxide binder, and a phosphate binder. The slurry is then allowed to cure to a solid, hydrated CBPC matrix. Next, bound water within the solid, hydrated CBPC matrix is removed. Typically, the bound water is removed by applying heat to the cured CBPC matrix. Preferably, the quantity of heat applied to the cured CBPC matrix is sufficient to drive off water bound within the hydrated CBPC matrix, but not to volatalize other non-water components of the matrix, such as metals and radioactive components. Typically, a temperature range of between 100.degree. C.-200.degree. C. will be sufficient. In another embodiment of the invention wherein the waste and water have been mixed prior to the preparation of the slurry, a select amount of water may be evaporated from the waste and water mixture prior to preparation of the slurry. Another aspect of the invention is a direct anyhydrous CBPC fabrication method wherein water is removed from the slurry by heating and mixing the slurry while allowing the slurry to cure. Additional aspects of the invention are ceramic matrix waste forms prepared by the methods disclosed above.

  12. On the Modelling of Mechanical Dewatering in Papermaking

    OpenAIRE

    Lobosco, Vinicius

    2004-01-01

    Most of the water fed into a paper machine is removedmechanically in the forming and press sections. One of thefactor which has an important influence on mechanicaldewatering, i.e. in both forming and pressing, is thestress-strain behaviour of the fibre network. The focus of this thesis is on the development of improvedmathematical descriptions of the stress-strain behaviourexhibited by fibre networks in the forming and press sections.The first part of the thesis presents a physically based m...

  13. Dewatering Techniques for Gas Recovery in Sichuan Gas Fields

    Institute of Scientific and Technical Information of China (English)

    Xu Kefang

    1996-01-01

    @@ Through several years' study for geology and development behavior of the gas fields, we realized that the water-bearing gas pools in Sichuan gas fields almost belong to enclosed weak elastic water drive gas pools, whether edge water gas pools or bottom water gas pools. According to the verification of drilling and production behavior data, in the periphery of Sichuan water-bearing gas pools, a screen is formed by gypsum salt, mudstone, or tight bed rock, with very low permeability, which blocks water percolation.

  14. INCREASE OF INDICATOR ORGANISMS FOLLOWING ANAEROBIC DIGESTION AND CENTRIFUGE DEWATERING.

    Science.gov (United States)

    The Water Environment Research Foundation (WERF) recently published a report titled “Examination of Reactivation and Regrowth of Fecal Coliforms in Anaerobically Digested Sludges”. Seven full-scale publicly owned treatment facilities were sampled several times to determine if bac...

  15. INCREASE OF INDICATOR ORGANISMS FOLLOWING ANAEROBIC DIGESTION AND CENTRIFUGE DEWATERING.

    Science.gov (United States)

    The Water Environment Research Foundation (WERF) recently published a report titled “Examination of Reactivation and Regrowth of Fecal Coliforms in Anaerobically Digested Sludges”. Seven full-scale publicly owned treatment facilities were sampled several times to determine if bac...

  16. Sewer Processes

    DEFF Research Database (Denmark)

    Hvitved-Jacobsen, Thorkild; Vollertsen, Jes; Nielsen, Asbjørn Haaning

    by hydrogen sulfide and other volatile organic compounds, as well as other potential health issues, have caused environmental concerns to rise. Reflecting the most current developments, Sewer Processes: Microbial and Chemical Process Engineering of Sewer Networks, Second Edition, offers the reader updated...... revisions of chapters from the previous edition, adds three new chapters, and presents extensive study questions. • Presents new modeling tools for the design and operation of sewer networks • Establishes sewer processes as a key element in preserving water quality • Includes greatly expanded coverage...... of odor formation and prediction • Details the WATS sewer process model • Highlights the importance of aerobic, anoxic, and anaerobic processes Sewer Processes: Microbial and Chemical Process Engineering of Sewer Networks, Second Edition, provides a basis for up-to-date understanding and modeling of sewer...

  17. Magnetics Processing

    Data.gov (United States)

    Federal Laboratory Consortium — The Magnetics Processing Lab equipped to perform testing of magnetometers, integrate them into aircraft systems, and perform data analysis, including noise reduction...

  18. Design Processes

    DEFF Research Database (Denmark)

    Ovesen, Nis

    2009-01-01

    advantages and challenges of agile processes in mobile software and web businesses are identified. The applicability of these agile processes is discussed in re- gards to design educations and product development in the domain of Industrial Design and is briefly seen in relation to the concept of dromology......Inspiration for most research and optimisations on design processes still seem to focus within the narrow field of the traditional design practise. The focus in this study turns to associated businesses of the design professions in order to learn from their development processes. Through interviews...

  19. Stochastic processes

    CERN Document Server

    Parzen, Emanuel

    2015-01-01

    Well-written and accessible, this classic introduction to stochastic processes and related mathematics is appropriate for advanced undergraduate students of mathematics with a knowledge of calculus and continuous probability theory. The treatment offers examples of the wide variety of empirical phenomena for which stochastic processes provide mathematical models, and it develops the methods of probability model-building.Chapter 1 presents precise definitions of the notions of a random variable and a stochastic process and introduces the Wiener and Poisson processes. Subsequent chapters examine

  20. Handling Measures for Special Cases in Artificial Aggregate Processing Operation%人工骨料加工中特殊情况的处理措施

    Institute of Scientific and Technical Information of China (English)

    董婷; 唐瑞

    2014-01-01

    针对中国水电工程人工骨料加工过程中遭遇坚硬高强超磨蚀性岩石、易破碎岩石、同类岩石不同加工特性岩石等料源时,致使设备磨损大、出现骨料破碎性能差、脱泥难、针片状超标、成品砂石粉含量不可控及脱水时间长等问题提出处理措施,料源加工问题得到了圆满解决。%The raw materials such as the sound, strong and super abrasion rock, fragile rock and same type of rock with different process-ing characteristic in the artificial aggregate processing in hydropower projects in China result in large equipment abrasion, weak crushing performance, difficult mud removal, exceedance of aggregates in needle and chip, uncontrollable powder sediment content and time-con-suming dewatering operation.Aiming at those, corresponding measures are raised to solve issues on the material processing.

  1. A process for containment removal and waste volume reduction to remediate groundwater containing certain radionuclides, toxic metals and organics. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, L.P.; Killey, D.R.W.; Vijayan, S.; Wong, P.C.F. [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.

    1992-09-01

    A project to remove groundwater contaminants by an improved treatment process was performed during 1990 October--1992 March by Atomic Energy of Canada Limited for the United States Department of Energy, managed by Argonne National Laboratory. The goal was to generate high-quality effluent while minimizing secondary waste volume. Two effluent target levels, within an order of magnitude, or less than the US Drinking Water Limit, were set to judge the process effectiveness. The program employed mixed waste feeds containing cadmium, uranium, lead, iron, calcium, strontium-85-90, cesium-137, benzene and trichlorethylene in simulated and actual groundwater and soil leachate solutions. A combination of process steps consisting of sequential chemical conditioning, cross-flow microfiltration and dewatering by low temperature-evaporation, or filter pressing were effective for the treatment of mixed waste having diverse physico-chemical properties. A simplified single-stage version of the process was implemented to treat ground and surface waters contaminated with strontium-90 at the Chalk River Laboratories site. Effluent targets and project goals were met successfully.

  2. 城市污水厂脱水污泥施用对马尼拉草生长及其对重金属迁移转化的影响%EFFECT OF DEWATERED SEWAGE SLUDGE ON THE GROWTH OF MANILA GRASS AND TRANSFER OF HEAVY METALS

    Institute of Scientific and Technical Information of China (English)

    徐加庆; 于瑞莲; 郑建山

    2011-01-01

    Manilagrass was planted with direct application of dewatered and dried municipal sewage sludge collected from Xiamen Yundang Wastewater Treatment Plant under pot experiment.The effect of sludge application on the growth and yield of Manilagrass was determined,and the transfer and accumulation of heavy metals in the Manilagrass-soil system was discussed.The results showed that the sludge was rich in nitrogen,phosphorus,potassium and organic matter,and the contents of heavy metals studied were all lower than the limits of national standard,for the disposal of sludge from municipal wastewater treatment plant-quality of sludge used in gardens or parks(GB/T23486—2009).Application of sludge increased the growth and yield of Manilagrass,which presented the maximum values when the sludge content was 20%.But the growth of Manilagrass was significantly inhibited when the sludge content was more than 30%.The bio-accumulation factors of eleven studied heavy metals in Manilagrass were all lower than 1.0,and the bio-accumulation capacity of heavy metals in the tested Manilagrass-soil systems is as follows: CuZnCdCoAsNiVMnPbFeCr.After the planting experiment,the chemical speciation of heavy metals in the rhizosphere soils transformed to some extent.Cd,Cr and As transformed from residual into bio-available fraction,Cu and Zn transformed from oxidizable into acid-soluble and reducible fractions,Mn transformed from reducible into acid-soluble and residual fractions,Ni transformed from bio-available into residual fraction significantly,Co transformed from acid-soluble and reducible into residual fraction,while Pb,Fe and V showed no significant transformation in chemical speciation.%以厦门市筼筜污水处理厂的脱水干化污泥作为有机肥种植马尼拉草,通过盆栽试验,探讨污泥直接施用对马尼拉草生长和产量的影响及重金属在马尼拉草-土壤间的迁移转化和积累情况.结果表明,污泥中氮、磷、钾和有机质含量丰

  3. 考虑孔隙比和渗透系数随土体当前应力变化的深基坑降水开挖变形分析%Deformation of deep foundation pits due to excavation and dewatering considering the change of void ratio and permeability coefficient with current stress of soil

    Institute of Scientific and Technical Information of China (English)

    邵羽; 江杰; 马少坤; 吕海波; 何建兴; 陈俊羽

    2015-01-01

    基于修正剑桥模型理论,推导了孔隙比 e随土体当前应力变化的方程,同时比选了4组经典的描述渗透系数 k随孔隙比变化的方程,选择了其中一组最佳的估算公式,编写ABAQUS用户子程序VOIDRI和USDFLD ,以实现孔隙比和渗透系数随土体当前应力的变化。在此基础上,研究深基坑降水开挖所致的坑内外土体的变形、围护结构的变形及弯矩,得到以下结论:当考虑孔隙比随土体当前应力变化时,坑外地表沉降量、墙体的水平位移、地下连续墙的弯矩、坑底隆起量均大于孔隙比为定值时的情况;当考虑渗透系数随土体当前应力变化时,坑外地表沉降量、墙体的水平位移、地下连续墙的弯矩均小于渗透系数为定值时的情况,但同时考虑渗透系数和孔隙比变化情况时,其对坑底的隆起量的影响可以忽略不计。%The function of void radio e changing with current stress was derived using the theory of Modified Cam‐Clay Model .Simultaneously ,four groups of classic estimate formula about permeability coefficient changing with void radio were compared to identify the accurate one . User subroutines VOIDRI and USDFLD in ABAQUS were compiled to realize the variation of void radio and permeability coefficient along with the change of current stress of soil . Then the soil displacement ,the deformation and the bending moment of retaining structure caused by excavation and dewatering with or without considering the change of void ratio and permeability coefficient with current stress of soil were compared .The results showed that i with changing void ratio ,values of ground settlement horizontal displacement of diaphragm wall ,bending moment of diaphragm wall and rebound at bottom were larger than those with constant void radio .When permeability coefficient changed with current stress of soil ,values of ground settlement ,horizontal displacement and bending moment of

  4. Image processing

    NARCIS (Netherlands)

    Heijden, van der F.; Spreeuwers, L.J.; Blanken, H.M.; Vries de, A.P.; Blok, H.E.; Feng, L

    2007-01-01

    The field of image processing addresses handling and analysis of images for many purposes using a large number of techniques and methods. The applications of image processing range from enhancement of the visibility of cer- tain organs in medical images to object recognition for handling by industri

  5. Sustainable processing

    DEFF Research Database (Denmark)

    Kristensen, Niels Heine

    2004-01-01

    Kristensen_NH and_Beck A: Sustainable processing. In Otto Schmid, Alexander Beck and Ursula Kretzschmar (Editors) (2004): Underlying Principles in Organic and "Low-Input Food" Processing - Literature Survey. Research Institute of Organic Agriculture FiBL, CH-5070 Frick, Switzerland. ISBN 3-906081-58-3...

  6. Process mining

    DEFF Research Database (Denmark)

    van der Aalst, W.M.P.; Rubin, V.; Verbeek, H.M.W.

    2010-01-01

    Process mining includes the automated discovery of processes from event logs. Based on observed events (e.g., activities being executed or messages being exchanged) a process model is constructed. One of the essential problems in process mining is that one cannot assume to have seen all possible...... behavior. At best, one has seen a representative subset. Therefore, classical synthesis techniques are not suitable as they aim at finding a model that is able to exactly reproduce the log. Existing process mining techniques try to avoid such “overfitting” by generalizing the model to allow for more...... behavior. This generalization is often driven by the representation language and very crude assumptions about completeness. As a result, parts of the model are “overfitting” (allow only for what has actually been observed) while other parts may be “underfitting” (allowfor much more behavior without strong...

  7. Process for increased biogas production and energy efficient hygienisation of sludge; Process foer oekad biogasproduktion och energieffektiv hygienisering av slam

    Energy Technology Data Exchange (ETDEWEB)

    Rogstrand, Gustav; Olsson, Henrik; Andersson Chan, Anneli; Johansson, Niklas; Edstroem, Mats

    2012-07-01

    In Sweden there is a need to increase biogas production to meet the rising demand for biomethane as vehicle fuel but the amount of domestically available biomass to digest is limited. One way to help meet current and future demand for methane is to enhance the digestion of the substrates that are currently utilized. Vaexjoe municipality in southern Sweden is in the process of upgrading their facilities for biogas production at the Sundet waste water treatment plant. Their aim is to produce more biogas in order to meet the demand from an increasing methane-based local transit fleet. This is the backdrop to a joint project between JTI and Vaexjoe municipality where JTI's mobile pilot plant was used to study the possibility of extracting more biogas from the existing sewage sludge. In the future, Vaexjoe municipality also plans to co-digest source separated municipal organics with the sewage sludge, which will likely result in stricter demands in terms of hygienization of all utilized substrates. The goal of the project at hand was to demonstrate the possibility to produce more than enough additional biogas from existing sewage sludge to yield a net energy profit even with the added energy demand of ensuring the hygienic quality of the digestate through conventional pasteurization. Although the project was focused on the conditions at Sundet waste water treatment plant, the issues dealt with are general and the results are relevant to many waste water treatment plants in Sweden. The research, conducted between June 2011 and January 2012 were divided into two trials. The two trials, described schematically in Figure 1, represented two possible process configurations designed to reach the goal stated above. The key component of both process configurations is the addition of a post-digestion step to the existing single-step digestion process. In trial 1 the additional feature of dewatering between the two digestion steps served to reduce energy demand for

  8. Organizing Process

    DEFF Research Database (Denmark)

    Hull Kristensen, Peer; Bojesen, Anders

    This paper invites to discuss the processes of individualization and organizing being carried out under what we might see as an emerging regime of change. The underlying argumentation is that in certain processes of change, competence becomes questionable at all times. The hazy characteristics...... of this regime of change are pursued through a discussion of competencies as opposed to qualifications illustrated by distinct cases from the Danish public sector in the search for repetitive mechanisms. The cases are put into a general perspective by drawing upon experiences from similar change processes...

  9. Grants Process

    Science.gov (United States)

    The NCI Grants Process provides an overview of the end-to-end lifecycle of grant funding. Learn about the types of funding available and the basics for application, review, award, and on-going administration within the NCI.

  10. Processing Proteases

    DEFF Research Database (Denmark)

    Ødum, Anders Sebastian Rosenkrans

    Processing proteases are proteases which proteolytically activate proteins and peptides into their biologically active form. Processing proteases play an important role in biotechnology as tools in protein fusion technology. Fusion strategies where helper proteins or peptide tags are fused...... to the protein of interest are an elaborate method to optimize expression or purification systems. It is however critical that fusion proteins can be removed and processing proteases can facilitate this in a highly specific manner. The commonly used proteases all have substrate specificities to the N...... of few known proteases to have substrate specificity for the C-terminal side of the scissile bond. LysN exhibits specificity for lysine, and has primarily been used to complement trypsin in to proteomic studies. A working hypothesis during this study was the potential of LysN as a processing protease...

  11. Electrochemical Processes

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers

    1997-01-01

    The notes describe in detail primary and secondary galvanic cells, fuel cells, electrochemical synthesis and electroplating processes, corrosion: measurments, inhibitors, cathodic and anodic protection, details of metal dissolution reactions, Pourbaix diagrams and purification of waste water from...

  12. Sewer Processes

    DEFF Research Database (Denmark)

    Hvitved-Jacobsen, Thorkild; Vollertsen, Jes; Nielsen, Asbjørn Haaning

    and valuable information on the sewer as a chemical and biological reactor. It focuses on how to predict critical impacts and control adverse effects. It also provides an integrated description of sewer processes in modeling terms. This second edition is full of illustrative examples and figures, includes...... microbial and chemical processes and demonstrates how this knowledge can be applied for the design, operation, and the maintenance of wastewater collection systems. The authors add chemical and microbial dimensions to the design and management of sewer networks with an overall aim of improved sustainability...... by hydrogen sulfide and other volatile organic compounds, as well as other potential health issues, have caused environmental concerns to rise. Reflecting the most current developments, Sewer Processes: Microbial and Chemical Process Engineering of Sewer Networks, Second Edition, offers the reader updated...

  13. Manufacturing processes

    Science.gov (United States)

    Bennet, Jay; Brower, David; Levine, Stan; Walker, Ray; Wooten, John

    1991-01-01

    The following issues are covered: process development frequently lags behind material development, high fabrication costs, flex joints (bellows) - a continuing program, SRM fabrication-induced defects, and in-space assembly will require simplified design.

  14. In process...

    OpenAIRE

    LI Xin

    1999-01-01

    Architecture is a wonderful world. As a student of architecture, time and time again I am inpressed by its powerful imagines. The more I study and learn, however, the more I question. What is the truth beyond those fantastic imagines? What is the nuture of Architecture? Is there any basic way or process to approach the work of Architecture? With these questions, I begin my thesis project and the process of looking for answers. MArch

  15. In process...

    OpenAIRE

    LI Xin

    2000-01-01

    Architecture is a wonderful world. As a student of architecture, time and time again I am inpressed by its powerful imagines. The more I study and learn, however, the more I question. What is the truth beyond those fantastic imagines? What is the nuture of Architecture? Is there any basic way or process to approach the work of Architecture? With these questions, I begin my thesis project and the process of looking for answers.

  16. Renewal processes

    CERN Document Server

    Mitov, Kosto V

    2014-01-01

    This monograph serves as an introductory text to classical renewal theory and some of its applications for graduate students and researchers in mathematics and probability theory. Renewal processes play an important part in modeling many phenomena in insurance, finance, queuing systems, inventory control and other areas. In this book, an overview of univariate renewal theory is given and renewal processes in the non-lattice and lattice case are discussed. A pre-requisite is a basic knowledge of probability theory.

  17. Advanced Multi-Product Coal Utilization By-Product Processing Plant

    Energy Technology Data Exchange (ETDEWEB)

    John Groppo; Thomas Robl

    2005-06-01

    The objective of the project is to build a multi-product ash beneficiation plant at Kentucky Utilities 2,200-MW Ghent Generating Station, located in Carroll County, Kentucky. This part of the study includes the examination of the feedstocks for the beneficiation plant. The ash, as produced by the plant, and that stored in the lower pond were examined. Filter media candidates were evaluated for dewatering the ultrafine ash (UFA) product. Media candidates were selected based on manufacturer recommendations and evaluated using standard batch filtration techniques. A final media was selected; 901F, a multifilament polypropylene. While this media would provide adequate solids capture and cake moisture, the use of flocculants would be necessary to enable adequate filter throughput. Several flocculant chemistries were also evaluated and it was determined that polyethylene oxide (PEO) at a dosage of 5 ppm (slurry basis) would be the most suitable in terms of both settling rate and clarity. PEO was evaluated on a continuous vacuum filter using 901F media. The optimum cycle time was found to be 1.25 minutes which provided a 305% moisture cake, 85% solids capture with a throughput of 115 lbs dry solids per hour and a dry cake rate of 25 lb/ft2/hr. Increasing cycle time not did not reduce cake moisture or increase throughput. A mobile demonstration unit has been designed and constructed for field demonstration. The continuous test unit will be operated at the Ghent site and will evaluate three processing configurations while producing sufficient products to facilitate thorough product testing. The test unit incorporates all of the unit processes that will be used in the commercial design and is self sufficient with respect to water, electricity and processing capabilities.

  18. Combination of alkaline and microwave pretreatment for disintegration of meat processing wastewater sludge.

    Science.gov (United States)

    Erden, G

    2013-01-01

    Meat processing wastewater sludge has high organic content but it is very slow to degrade in biological processes. Anaerobic digestion may be a good alternative for this type of sludge when the hydrolysis, known to be the rate-limiting step of biological sludge anaerobic degradation, could be eliminated by disintegration. This investigation deals with disintegration of meat processing wastewater sludge. Microwave (MW) irradiation and combined alkaline pretreatment and MW irradiation were applied to sludge for disintegration purposes. Disintegration performance of the methods was evaluated with disintegration degree based on total and dissolved organic carbon calculations (DD(TOC)), and the solubilization of volatile solids (S(VS)) in the pretreated sludge. Optimum conditions were found to be 140 degrees C and 30 min for MW irradiation using response surface methodology (RSM) and pH = 13 for combined pretreatment. While DD(TOC) was observed as 24.6% and 54.9, S(VS) was determined as 8.54% and 42.5% for MW pretreated and combined pretreated sludge, respectively. The results clearly show that pre-conditioning of sludge with alkaline pretreatment played an important role in enhancing the disintegration efficiency of subsequent MW irradiation. Disintegration methods also affected the anaerobic biodegradability and dewaterability of sludge. An increase of 23.6% in biogas production in MW irradiated sludge was obtained, comparing to the raw sludge at the end of the 35 days of incubation. This increase was observed as 44.5% combined pretreatment application. While MW pretreatment led to a little improvement of the dewatering performance of sludge, in combined pretreatment NaOH deteriorates the sludge dewaterability.

  19. Proceedings of the 45. annual conference of metallurgists of CIM : interfacial phenomena in fine particle technology : the 6. UBC-McGill-UA international symposium on fundamentals of mineral processing in honor of Professor Janusz S. Laskowski

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z.; Liu, Q. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering] (eds.)

    2006-07-01

    This conference, organized by the Mineral Sciences and Engineering Section of the Metallurgical Society of CIM acknowledged that strong economic growth is the driving force behind record high productivity in the mining industry. The industry must strive to meet the higher demand for raw materials while facing the challenge of stringent environmental constraints. The continuing success of the mining industry will depend on efficient and environmentally sound mineral processing, particularly since the industry has been forced to exploit more complex forms of minerals given the gradual depletion of high-grade mineral resources. In addition to shortages in qualified personnel in mineral processing, the industry is currently facing a general reduction in basic research and training programs, resulting in deficiencies in technologies needed to process complex ores. World experts in mineral processing participated at this conference to share their novel research in fine particle processing, applications of atomic force microscopy, flotation research, particle interactions in mineral processing, flotation froths, grinding, rheology and sulphide flotation chemistry. The sessions of the conference were entitled: atomic force microscopy in flotation research particulate interactions; flotation froths, flocculation and dewatering; grinding and rheology surfactants; flotation froths, particle-bubble interactions; sulphide flotation; and, general flotation froths. The conference featured 37 presentations, of which 6 have been catalogued separately for inclusion in this database. refs., tabs., figs.

  20. Geohydrologic feasibility study of the Powder River Basin for the potential application of a production process patented by Jack W. McIntyre

    Energy Technology Data Exchange (ETDEWEB)

    Kvasnicka, D.E.

    1993-08-01

    Geraghty & Miller, Inc. of Midland, Texas conducted geologic and hydrologic feasibility studies of the potential applicability of a patented (US Patent Office No. 4,766,957) process developed by Jack W. McIntyre for the recovery of natural gas from coalbed/sand formations in the Powder River Basin. General research, based on a review of published literature from both private and public sources, indicates that the shallow, thick subbituminous coal seams found in the Powder River Basin exhibit significant potential for the application of this patented process. These coal deposits can be characterized, on the basis of established coalbed methane production, as being highly water productive. The desorption and economic recovery of coalbed methane, widely believed to be biogenic in origin, from these low-grade deposits will require the subsequent dewatering of these geologic formations. The patented process, developed by Mr. McIntyre and described in the compendium of this study, may offer a cost-effective means of methane recovery and downhole disposal of produced groundwaters.

  1. Forward osmosis for the treatment of reverse osmosis concentrate from water reclamation: process performance and fouling control.

    Science.gov (United States)

    Kazner, C; Jamil, S; Phuntsho, S; Shon, H K; Wintgens, T; Vigneswaran, S

    2014-01-01

    While high quality water reuse based on dual membrane filtration (membrane filtration or ultrafiltration, followed by reverse osmosis) is expected to be progressively applied, treatment and sustainable management of the produced reverse osmosis concentrate (ROC) are still important issues. Forward osmosis (FO) is a promising technology for maximising water recovery and further dewatering ROC so that zero liquid discharge is produced. Elevated concentrations of organic and inorganic compounds may act as potential foulants of the concentrate desalting system, in that they consist of, for example, FO and a subsequent crystallizer. The present study investigated conditions under which the FO system can serve as concentration phase with the focus on its fouling propensity using model foulants and real ROC. Bulk organics from ROC consisted mainly of humic acids (HA) and building blocks since wastewater-derived biopolymers were retained by membrane filtration or ultrafiltration. Organic fouling of the FO system by ROC-derived bulk organics was low. HA was only adsorbed moderately at about 7% of the initial concentration, causing a minor flux decline of about 2-4%. However, scaling was a major impediment to this process if not properly controlled, for instance by pH adjustment or softening.

  2. 热塑性酚醛树脂合成中废水游离酚含量的测定方法%The Method for Determination of Free Phenol Content in Waste Water During Thermal Plastic Phenol-Formaldehyde Resin Synthesis Process

    Institute of Scientific and Technical Information of China (English)

    张苏静; 黄仁和

    2013-01-01

    工业生产中,热塑性酚醛树脂的合成过程会产生大量废水,废水中含有部分游离态的苯酚、甲醛,为了合理回收利用废水,需要对游离酚含量进行测定.本文比较并分析了目前现有的两种不同的测定游离酚的方法,得出用溴量法更适合于测定废水中的游离酚,该方法准确度及精确度较高,适合测定热塑性酚醛树脂废水中的游离酚含量.将合成过程产生的废水分步脱出,用溴量法测定其酚含量,然后将分步脱出的废水采取不同方法再回收使用.%In industrial production, the synthesizing process of thermoplastic phenol-formaldehyde resin will produce large quantities of waste water, which contains part of free phenol and formaldehyde. In order to recycle the waste water reasonably, it is necessary to determine the content of free phenol. This paper compares and analyzes the two methods of determining free phenol content nowadays. The analysis results show that bromometry is better for the determination. It has high accuracy, and bromometry is suitable for determining the free phenol content in the thermal plastic phenol-formaldehyde resin waste water. Free phenol content that occur during the fractional dewatering step is determined by bromometry, and the waste water of different dewatering step is recycled by different methods.

  3. Macdonald processes

    CERN Document Server

    Borodin, Alexei

    2011-01-01

    Macdonald processes are probability measures on sequences of partitions defined in terms of nonnegative specializations of the Macdonald symmetric functions and two Macdonald parameters q,t in [0,1). We prove several results about these processes, which include the following. (1) We explicitly evaluate expectations of a rich family of observables for these processes. (2) In the case t=0, we find a Fredholm determinant formula for a q-Laplace transform of the distribution of the last part of the Macdonald-random partition. (3) We introduce Markov dynamics that preserve the class of Macdonald processes and lead to new "integrable" 2d and 1d interacting particle systems. (4) In a large time limit transition, and as q goes to 1, the particles of these systems crystallize on a lattice, and fluctuations around the lattice converge to O'Connell's Whittaker process that describe semi-discrete Brownian directed polymers. (5) This yields a Fredholm determinant for the Laplace transform of the polymer partition function...

  4. Offshoring Process

    DEFF Research Database (Denmark)

    Slepniov, Dmitrij; Sørensen, Brian Vejrum; Katayama, Hiroshi

    2011-01-01

    The purpose of this chapter is to contribute to the knowledge on how production offshoring and international operations management vary across cultural contexts. The chapter attempts to shed light on how companies approach the process of offshoring in different cultural contexts. In order...... of globalisation. Yet there are clear differences in how offshoring is conducted in Denmark and Japan. The main differences are outlined in a framework and explained employing cultural variables. The findings lead to a number of propositions suggesting that the process of offshoring is not simply a uniform...

  5. Offshoring Process

    DEFF Research Database (Denmark)

    Slepniov, Dmitrij; Sørensen, Brian Vejrum; Katayama, Hiroshi

    2011-01-01

    The purpose of this chapter is to contribute to the knowledge on how production offshoring and international operations management vary across cultural contexts. The chapter attempts to shed light on how companies approach the process of offshoring in different cultural contexts. In order...... of globalisation. Yet there are clear differences in how offshoring is conducted in Denmark and Japan. The main differences are outlined in a framework and explained employing cultural variables. The findings lead to a number of propositions suggesting that the process of offshoring is not simply a uniform...

  6. Design, experimentation, and modeling of a novel continuous biodrying process

    Science.gov (United States)

    Navaee-Ardeh, Shahram

    Massive production of sludge in the pulp and paper industry has made the effective sludge management increasingly a critical issue for the industry due to high landfill and transportation costs, and complex regulatory frameworks for options such as sludge landspreading and composting. Sludge dewatering challenges are exacerbated at many mills due to improved in-plant fiber recovery coupled with increased production of secondary sludge, leading to a mixed sludge with a high proportion of biological matter which is difficult to dewater. In this thesis, a novel continuous biodrying reactor was designed and developed for drying pulp and paper mixed sludge to economic dry solids level so that the dried sludge can be economically and safely combusted in a biomass boiler for energy recovery. In all experimental runs the economic dry solids level was achieved, proving the process successful. In the biodrying process, in addition to the forced aeration, the drying rates are enhanced by biological heat generated through the microbial activity of mesophilic and thermophilic microorganisms naturally present in the porous matrix of mixed sludge. This makes the biodrying process more attractive compared to the conventional drying techniques because the reactor is a self-heating process. The reactor is divided into four nominal compartments and the mixed sludge dries as it moves downward in the reactor. The residence times were 4-8 days, which are 2-3 times shorter than the residence times achieved in a batch biodrying reactor previously studied by our research group for mixed sludge drying. A process variable analysis was performed to determine the key variable(s) in the continuous biodrying reactor. Several variables were investigated, namely: type of biomass feed, pH of biomass, nutrition level (C/N ratio), residence times, recycle ratio of biodried sludge, and outlet relative humidity profile along the reactor height. The key variables that were identified in the continuous

  7. Optical Processing.

    Science.gov (United States)

    1985-12-31

    34perceptron" (F. Rosenblatt, Principles of Neurodynamics ), workers in the neural network field have been seeking to understand how neural networks can perform...Moscow). 13. F. Rosenblatt, Principles of Neurodynamics , (Spartan, 1962). 14. W. Stoner "Incoherent optical processing via spatially offset pupil

  8. Innovation process

    DEFF Research Database (Denmark)

    Kolodovski, A.

    2006-01-01

    Purpose of this report: This report was prepared for RISO team involved in design of the innovation system Report provides innovation methodology to establish common understanding of the process concepts and related terminology The report does not includeRISO- or Denmark-specific cultural, econom...

  9. Processing Determinism

    Science.gov (United States)

    O'Grady, William

    2015-01-01

    I propose that the course of development in first and second language acquisition is shaped by two types of processing pressures--internal efficiency-related factors relevant to easing the burden on working memory and external input-related factors such as frequency of occurrence. In an attempt to document the role of internal factors, I consider…

  10. Processing Branches

    DEFF Research Database (Denmark)

    Schindler, Christoph; Tamke, Martin; Tabatabai, Ali;

    2014-01-01

    Angled and forked wood – a desired material until 19th century, was swept away by industrialization and its standardization of processes and materials. Contemporary information technology has the potential for the capturing and recognition of individual geometries through laser scanning and compu...

  11. BENTONITE PROCESSING

    Directory of Open Access Journals (Sweden)

    Anamarija Kutlić

    2012-07-01

    Full Text Available Bentonite has vide variety of uses. Special use of bentonite, where its absorbing properties are employed to provide water-tight sealing is for an underground repository in granites In this paper, bentonite processing and beneficiation are described.

  12. espida Process

    OpenAIRE

    Currall, James; McKinney, Peter

    2006-01-01

    Embedded in the work of espida is a process that ensures projects align themselves with the strategic aims of the funders they wish to receive resources from. It details the relationship the funder and fundee have and how outcomes of the work feedback into the organisational objectives.

  13. Environmental consequences of processing manure to produce mineral fertilizer and bio-energy.

    Science.gov (United States)

    De Vries, J W; Groenestein, C M; De Boer, I J M

    2012-07-15

    Liquid animal manure and its management contributes to environmental problems such as, global warming, acidification, and eutrophication. To address these environmental issues and their related costs manure processing technologies were developed. The objective here was to assess the environmental consequences of a new manure processing technology that separates manure into a solid and liquid fraction and de-waters the liquid fraction by means of reverse osmosis. This results in a liquid mineral concentrate used as mineral nitrogen and potassium fertilizer and a solid fraction used for bio-energy production or as phosphorus fertilizer. Five environmental impact categories were quantified using life cycle assessment: climate change (CC), terrestrial acidification (TA), marine eutrophication (ME), particulate matter formation (PMF), and fossil fuel depletion (FFD). For pig as well as dairy cattle manure, we compared a scenario with the processing method and a scenario with additional anaerobic digestion of the solid fraction to a reference situation applying only liquid manure. Comparisons were based on a functional unit of 1 ton liquid manure. System boundaries were set from the manure storage under the animal house to the field application of all end products. Scenarios with only manure processing increased the environmental impact for most impact categories compared to the reference: ME did not change, whereas, TA and PMF increased up to 44% as a result of NH3 and NO(x) emissions from processing and storage of solid fraction. Including digestion reduced CC by 117% for pig manure and 104% for dairy cattle manure, mainly because of substituted electricity and avoided N2O emission from storage of solid fraction. FFD decreased by 59% for pig manure and increased 19% for dairy cattle manure. TA and PMF remained higher compared to the reference. Sensitivity analysis showed that CH4 emission from manure storage, NH3 emission from processing, and the replaced nitrogen

  14. Photobiomodulation Process

    Directory of Open Access Journals (Sweden)

    Yang-Yi Xu

    2012-01-01

    Full Text Available Photobiomodulation (PBM is a modulation of laser irradiation or monochromatic light (LI on biosystems. There is little research on PBM dynamics although its phenomena and mechanism have been widely studied. The PBM was discussed from dynamic viewpoint in this paper. It was found that the primary process of cellular PBM might be the key process of cellular PBM so that the transition rate of cellular molecules can be extended to discuss the dose relationship of PBM. There may be a dose zone in which low intensity LI (LIL at different doses has biological effects similar to each other, so that biological information model of PBM might hold. LIL may self-adaptively modulate a chronic stress until it becomes successful.

  15. Boolean process

    Institute of Scientific and Technical Information of China (English)

    闵应骅; 李忠诚; 赵著行

    1997-01-01

    Boolean algebra successfully describes the logical behavior of a digital circuit, and has been widely used in electronic circuit design and test With the development of high speed VLSIs it is a drawback for Boolean algebra to be unable to describe circuit timing behavior. Therefore a Boolean process is defined as a family of Boolean van ables relevant to the time parameter t. A real-valued sample of a Boolean process is a waveform. Waveform functions can be manipulated formally by using mathematical tools. The distance, difference and limit of a waveform polynomial are defined, and a sufficient and necessary condition of the limit existence is presented. Based on this, the concept of sensitization is redefined precisely to demonstrate the potential and wide application possibility The new definition is very different from the traditional one, and has an impact on determining the sensitizable paths with maximum or minimum length, and false paths, and then designing and testing high performance circuits

  16. Purification process

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, A.

    1981-02-17

    A process for the removal of hydrogen sulphide from gases or liquid hydrocarbons, comprises contacting the gas or liquid hydrocarbon with an aqueous alkaline solution, preferably having a pH value of 8 to 10, comprising (A) an anthraquinone disulphonic acid or a water-soluble sulphonamide thereof (B) a compound of a metal which can exist in at least two valency states and (C) a sequestering agent.

  17. O feedback e sua importância no processo de tutoria a distância Feedback and its importance to the distance education tutoring process

    Directory of Open Access Journals (Sweden)

    Denise Martins de Abreu-e-Lima

    2011-08-01

    Full Text Available Considerando o crescimento da Educação a Distância no contexto brasileiro; o ingresso de um novo profissional da educação - o tutor - na equipe pedagógica; e a importância de sua interação com os alunos, este artigo tem como objetivos revisar algumas definições de feedback encontradas na literatura, descrever os modelos de feedback adotados nos cursos de EaD ministrados em uma universidade federal brasileira, apresentar as orientações dadas nos cursos de formação de tutores realizados pela instituição e discutir o papel da linguagem nos processos de feedback. De acordo com a discussão feita, são apontadas as principais diretrizes para a utilização de feedback em ambientes virtuais.Taking into consideration the growth of Distance Education field in the Brazilian educational context, the new roles of teaching such as the tutor in the teaching team, this paper aims to review some definitions of feedback found in current literature as well as to point out the models of feedback adopted at Distance Education programs offered by a Brazilian Federal University. It also aims to present the guidelines given to online tutors engaged in the courses offered by these institutional programs and to discuss the role of language in the feedback process. According with the present discussion, some guidelines to the use of feedback in online environment are given.

  18. A interatividade na educação a distância: avanços e desafios

    Directory of Open Access Journals (Sweden)

    Edna Cristina do Prado

    2008-01-01

    Full Text Available Demand is discussed in this article the importance of interactivity in the education process provided in the form of Distance at Education (EAD, above, bringing aspects related to theories of learning and the challenges that still have to consolidate the EAD. These challenges can be pointing the prejudice existing in relation to EAD and the need for preparation of a project of course guided in a new design on the teaching and learning process. The construction of a new educational paradigm that can enable the democratization of education requires an effort that more conceptual, requires urgent, the construction of a network of social learning and research that can strengthen the growth and recovery of EAD.

  19. [Limits and possibilities of distance learning in continuing education in health: integrative review].

    Science.gov (United States)

    Silva, Adriane das Neves; dos Santos, Ana Maria Gualberto; Cortez, Elaine Antunes; Cordeiro, Benedito Carlos

    2015-04-01

    This is a study on the use of distance learning (EaD, in Portuguese) as a teaching strategy in continuing health education (EPS, in Portuguese), which aimed to identify and analyze the limits and posibilities of using EaD in the EPS. Integrative Review Study. The result shows that EaD is an innovative, possible and potential strategy for EPS, facilitating the development of learning within or outside the health institution, although is evident the lack of research in the area. The limitations for the implementation of the programs are related to the time variable, preparation for dealing with the technologies and the importance of the tutor as a facilitator of learning. It concludes that the use of EaD has an important contribution to the development of human resources in health, is in the process of training and/or in the continuous knowledge process.

  20. Ceramic Processing

    Energy Technology Data Exchange (ETDEWEB)

    EWSUK,KEVIN G.

    1999-11-24

    Ceramics represent a unique class of materials that are distinguished from common metals and plastics by their: (1) high hardness, stiffness, and good wear properties (i.e., abrasion resistance); (2) ability to withstand high temperatures (i.e., refractoriness); (3) chemical durability; and (4) electrical properties that allow them to be electrical insulators, semiconductors, or ionic conductors. Ceramics can be broken down into two general categories, traditional and advanced ceramics. Traditional ceramics include common household products such as clay pots, tiles, pipe, and bricks, porcelain china, sinks, and electrical insulators, and thermally insulating refractory bricks for ovens and fireplaces. Advanced ceramics, also referred to as ''high-tech'' ceramics, include products such as spark plug bodies, piston rings, catalyst supports, and water pump seals for automobiles, thermally insulating tiles for the space shuttle, sodium vapor lamp tubes in streetlights, and the capacitors, resistors, transducers, and varistors in the solid-state electronics we use daily. The major differences between traditional and advanced ceramics are in the processing tolerances and cost. Traditional ceramics are manufactured with inexpensive raw materials, are relatively tolerant of minor process deviations, and are relatively inexpensive. Advanced ceramics are typically made with more refined raw materials and processing to optimize a given property or combination of properties (e.g., mechanical, electrical, dielectric, optical, thermal, physical, and/or magnetic) for a given application. Advanced ceramics generally have improved performance and reliability over traditional ceramics, but are typically more expensive. Additionally, advanced ceramics are typically more sensitive to the chemical and physical defects present in the starting raw materials, or those that are introduced during manufacturing.

  1. Processing Proteases

    DEFF Research Database (Denmark)

    Ødum, Anders Sebastian Rosenkrans

    -terminal of the scissile bond, leaving C-terminal fusions to have non-native C-termini after processing. A solution yielding native C-termini would allow novel expression and purification systems for therapeutic proteins and peptides.The peptidyl-Lys metallopeptidase (LysN) of the fungus Armillaria mellea (Am) is one...... suitable to leave native C-termini.During this study the substrate specificity of LysN was profiled with a synthetic fluorogenic peptide library which allowed for kinetic characterization. A novel profiling method using encoded beads was proposed to efficiently profile human Renin. Recombinant expression...

  2. Hydrocarbon processing

    Energy Technology Data Exchange (ETDEWEB)

    Hill, S.G.; Seddon, D.

    1989-06-28

    A process for the catalytic conversion of synthesis-gas into a product which comprises naphtha, kerosene and distillate is characterized in that the catalyst is a Fischer-Tropsch catalyst also containing a zeolite, the naphtha fraction contains 60% or less linear paraffins and the kerosene and distillated fractions contain more linear paraffins and olefins than found in the naphtha fraction. Reduction of the relative amount of straight chain material in the naphtha fraction increases the octane number and so enhances the quality of the gasoline product, while the high quality of the kerosene and distillate fractions is maintained.

  3. 废水处理工程方案与工艺%Wastewater Treatment Engineering Scheme and Treatment Process

    Institute of Scientific and Technical Information of China (English)

    于淑萍

    2015-01-01

    对全厂废水处理站的工艺流程中的关键处理单元进行工艺优选。选择固定螺旋混合器作为絮凝沉淀系统的絮凝剂与处理水的混合装置,选择旋流混合反应器作为絮凝反应系统装置,采用斜管(板)式沉淀池作为絮凝沉淀系统的固液分离沉淀装置,厌氧处理系统选择两相厌氧工艺,好氧处理系统选择DAT-IAT工艺、污泥处理系统采用板框压滤脱水等设备及工艺处理废水。使企业在节能、降耗、提高废水处理后水质程度等方面发挥较好的经济、社会、环境效益。%Key processing unit of the process in the waste water treatment station was optimized. Fixed screw mixer mixing device was chose as flocculation sedimentation flocculant and water treatment system, cyclone reactor was selected as the flocculation reaction device, inclined tube sedimentation tank ( board) was used as flocculation precipitation device in solid-liquid separation system, two-phase anaerobic process and DAT-IAT technology were used in anaerobic treatment system and aerobic treatment system, the plate and frame filter press used dewatering sludge treatment systems and other equipment in the process of wastewater treatment, in order to improve wastewater treatment in saving energy and reducing consumption, economic, social, environmental benefits, play good quality, etc.

  4. Optical processing

    Science.gov (United States)

    Gustafson, S. C.

    1985-12-01

    The technical contributions were as follows: (1) Optical parallel 2-D neighborhood processor and optical processor assessment technique; (2) High accuracy with moderately accurate components and optical fredkin gate architectures; (3) Integrated optical threshold computing, pipelined polynomial processor, and all optical analog/digital converter; (4) Adaptive optical associative memory model with attention; (5) Effectiveness of parallelism and connectivity in optical computers; (6) Optical systolic array processing using an integrated acoustooptic module; (7) Optical threshold elements and networks, holographic threshold processors, adaptive matched spatial filtering, and coherence theory in optical computing; (8) Time-varying optical processing for sub-pixel targets, optical Kalman filtering, and adaptive matched filtering; (9) Optical degrees of freedom, ultra short optical pulses, number representations, content-addressable-memory processors, and integrated optical Givens rotation devices; (10) Optical J-K flip flop analysis and interfacing for optical computers; (11) Matrix multiplication algorithms and limits of incoherent optical computers; (12) Architecture for machine vision with sensor fusion, pattern recognition functions, and neural net implementations; (13) Optical computing algorithms, architectures, and components; and (14) Dynamic optical interconnections, advantages and architectures.

  5. ProUni e UAB como estratégias de EAD na expansão do ensino superior ProUni and UAB as EAD (distance education stategies for higher education expansion

    Directory of Open Access Journals (Sweden)

    Stella Cecília Duarte Segenreich

    2009-08-01

    Full Text Available Neste texto é feita uma análise dos programas Universidade para Todos (ProUni e Universidade Aberta do Brasil (UAB como estratégias de Educação a Distância promovidas pelo governo Lula na expansão e democratização do Ensino Superior. Questões tais como o número elevado de pólos, sua dispersão e distanciamento da sede da instituição promotora dos cursos, assim como a falta de avaliação da efetiva qualidade de ensino são desafios colocados ao ProUni, especificamente. No que se refere aos dois programas em conjunto, surgiram questões referentes ao modelo de pólo presencial adotado e ao conceito de tutoria e seu impacto na configuração do corpo docente das universidades. Constatou-se, ainda, um avanço significativo no reconhecimento de que a educação a distância não se resume a uma estratégia de mercantilização e privatização do ensino e que precisa ser pesquisada intensamente em termos de sua utilização como política de Estado e em termos das novas questões de ordem institucional e pedagógica que suscita.This text aims at analyzing the programs of University for All (ProUni and Brazilian Open University (UAB as products of the Lula government higher education expansion and democratization policy. Some issues like the great number of poles, their dispersion and distance from the headquarters of the promoting institution, as well as the lack of an evaluation mechanism to assess the quality of the education offered by the participant institutions, are challenges faced specifically by ProUni. As far as those two programs are concerned, some issues emerged related to the model of the classroom instruction pole which has been adopted and the concept of tutoring and its impact on the configuration of the teaching staff of universities. Also, significant improvement has been verified in the recognition that distance education does not limit itself to a commercial and privatizing educational strategy, but it must be studied in terms of its utilization as a state policy and in terms of the new institutional and pedagogical issues it raises.

  6. Lithospheric processes

    Energy Technology Data Exchange (ETDEWEB)

    Baldridge, W. [and others

    2000-12-01

    The authors used geophysical, geochemical, and numerical modeling to study selected problems related to Earth's lithosphere. We interpreted seismic waves to better characterize the thickness and properties of the crust and lithosphere. In the southwestern US and Tien Shari, crust of high elevation is dynamically supported above buoyant mantle. In California, mineral fabric in the mantle correlate with regional strain history. Although plumes of buoyant mantle may explain surface deformation and magmatism, our geochemical work does not support this mechanism for Iberia. Generation and ascent of magmas remains puzzling. Our work in Hawaii constrains the residence of magma beneath Hualalai to be a few hundred to about 1000 years. In the crust, heat drives fluid and mass transport. Numerical modeling yielded robust and accurate predictions of these processes. This work is important fundamental science, and applies to mitigation of volcanic and earthquake hazards, Test Ban Treaties, nuclear waste storage, environmental remediation, and hydrothermal energy.

  7. Crystallization process

    Science.gov (United States)

    Adler, Robert J.; Brown, William R.; Auyang, Lun; Liu, Yin-Chang; Cook, W. Jeffrey

    1986-01-01

    An improved crystallization process is disclosed for separating a crystallizable material and an excluded material which is at least partially excluded from the solid phase of the crystallizable material obtained upon freezing a liquid phase of the materials. The solid phase is more dense than the liquid phase, and it is separated therefrom by relative movement with the formation of a packed bed of solid phase. The packed bed is continuously formed adjacent its lower end and passed from the liquid phase into a countercurrent flow of backwash liquid. The packed bed extends through the level of the backwash liquid to provide a drained bed of solid phase adjacent its upper end which is melted by a condensing vapor.

  8. Image Processing

    Science.gov (United States)

    1993-01-01

    Electronic Imagery, Inc.'s ImageScale Plus software, developed through a Small Business Innovation Research (SBIR) contract with Kennedy Space Flight Center for use on space shuttle Orbiter in 1991, enables astronauts to conduct image processing, prepare electronic still camera images in orbit, display them and downlink images to ground based scientists for evaluation. Electronic Imagery, Inc.'s ImageCount, a spin-off product of ImageScale Plus, is used to count trees in Florida orange groves. Other applications include x-ray and MRI imagery, textile designs and special effects for movies. As of 1/28/98, company could not be located, therefore contact/product information is no longer valid.

  9. Adsorption of carbon dioxide (CO2) at S functionalized boron nitride (BN) and aluminum nitride (AlN) nanotubes (9, 0): A quantum chemical investigation

    Science.gov (United States)

    Najafi, Meysam

    2016-10-01

    We employed density functional theory to characterize CO2 adsorption on BNNT and AlNNT surfaces. The effects of S functionalization on the adsorption of CO2 gas on BNNT and AlNNT surfaces were investigated. Results reveal that adsorptions of CO2 on studied nanotubes were exothermic and experimentally possible from the energetic viewpoint. Results show that, Ead values of CO2 on AlNNT surface were more negative than corresponding values of BNNT. Results reveal that, S functionalization of studied nanotubes causes an increase in the absolute values of Ead of CO2 on surface of studied nanotubes. These results show that, there are good linearity dependencies between Ead and orbital energy values of studied nanotubes. Therefore we can conclude the Ead and orbital energy values are highly sensitive to the adsorption process which these may be used for the selection the suitable nanotubes with enhanced CO2 adsorption potential.

  10. Market Dominance, Efficiency, Innovation, and Globalization: A Case Study of the Tanker Competition Between Boeing and Northrop Grumman/EADS

    Science.gov (United States)

    2008-04-23

    corporate practices in the post- Enron world, to more up-to- date and open government procurement practices. These trends have resulted in the coalescence of...tankers from Boeing for $23.5 billion following a Pentagon procurement scandal , in which one of the key Air Force procurement officials, Darleen Druyen...and the CFO of Boeing, Michael Sears, went to jail. The scandal was brought to light partially with the assistance of Senator McCain’s office (Wolf

  11. Application of sludge-based carbonaceous materials in a hybrid water treatment process based on adsorption and catalytic wet air oxidation.

    Science.gov (United States)

    Julcour Lebigue, Carine; Andriantsiferana, Caroline; N'Guessan Krou; Ayral, Catherine; Mohamed, Elham; Wilhelm, Anne-Marie; Delmas, Henri; Le Coq, Laurence; Gerente, Claire; Smith, Karl M; Pullket, Suangusa; Fowler, Geoffrey D; Graham, Nigel J D

    2010-12-01

    This paper describes a preliminary evaluation of the performance of carbonaceous materials prepared from sewage sludges (SBCMs) in a hybrid water treatment process based on adsorption and catalytic wet air oxidation; phenol was used as the model pollutant. Three different sewage sludges were treated by either carbonisation or steam activation, and the physico-chemical properties of the resultant carbonaceous materials (e.g. hardness, BET surface area, ash and elemental content, surface chemistry) were evaluated and compared with a commercial reference activated carbon (PICA F22). The adsorption capacity for phenol of the SBCMs was greater than suggested by their BET surface area, but less than F22; a steam activated, dewatered raw sludge (SA_DRAW) had the greatest adsorption capacity of the SBCMs in the investigated range of concentrations (oxidation tests, the SBCMs demonstrated catalytic behaviour arising from their substrate adsorptivity and metal content. Recycling of SA_DRAW in successive oxidations led to significant structural attrition and a hardened SA_DRAW was evaluated, but found to be unsatisfactory during the oxidation step. In a combined adsorption-oxidation sequence, both the PICA carbon and a selected SBCM showed deterioration in phenol adsorption after oxidative regeneration, but a steady state performance was reached after 2 or 3 cycles.

  12. Dynamic Processes

    Science.gov (United States)

    Klingshirn, C.

    . Phys. Lett. 92:211105, 2008). For this point, recall Figs. 6.16 and 6.33. Since the polarisation amplitude is gone in any case after the recombination process, there is an upper limit for T 2 given by T 2 ≤ 2 T1. The factor of two comes from the fact that T 2 describes the decay of an amplitude and T 1 the decay of a population, which is proportional to the amplitude squared. Sometimes T 2 is subdivided in a term due to recombination described by T 1 and another called 'pure dephasing' called T 2 ∗ with the relation 1 / T 2 = 1 / 2 T 1 + 1 / T2 ∗. The quantity T 2 ∗ can considerably exceed 2 T 1. In the part on relaxation processes that is on processes contributing to T 3, we give also examples for the capture of excitons into bound, localized, or deep states. For more details on dynamics in semiconductors in general see for example, the (text-) books [Klingshirn, Semiconductor Optics, 3rd edn. (Springer, Berlin, 2006); Haug and Koch, Quantum Theory of the Optical and Electronic Properties of Semiconductors, 4th edn. (World Scientific, Singapore, 2004); Haug and Jauho, Quantum Kinetics in Transport and Optics of Semiconductors, Springer Series in Solid State Sciences vol. 123 (Springer, Berlin, 1996); J. Shah, Ultrafast Spectroscopy of Semiconductors and of Semiconductor Nanostructures, Springer Series in Solid State Sciences vol. 115 (Springer, Berlin, 1996); Schafer and Wegener, Semiconductor Optics and Transport Phenomena (Springer, Berlin, 2002)]. We present selected data for free, bound and localized excitons, biexcitons and electron-hole pairs in an EHP and examples for bulk materials, epilayers, quantum wells, nano rods and nano crystals with the restriction that - to the knowledge of the author - data are not available for all these systems, density ranges and temperatures. Therefore, we subdivide the topic below only according to the three time constants T 2, T 3 and T 1.

  13. Data Processing

    Science.gov (United States)

    Grangeat, P.

    A new area of biology has been opened up by nanoscale exploration of the living world. This has been made possible by technological progress, which has provided the tools needed to make devices that can measure things on such length and time scales. In a sense, this is a new window upon the living world, so rich and so diverse. Many of the investigative methods described in this book seek to obtain complementary physical, chemical, and biological data to understand the way it works and the way it is organised. At these length and time scales, only dedicated instrumentation could apprehend the relevant phenomena. There is no way for our senses to observe these things directly. One important field of application is molecular medicine, which aims to explain the mechanisms of life and disease by the presence and quantification of specific molecular entities. This involves combining information about genes, proteins, cells, and organs. This in turn requires the association of instruments for molecular diagnosis, either in vitro, e.g., the microarray or the lab-on-a-chip, or in vivo, e.g., probes for molecular biopsy, and tools for molecular imaging, used to localise molecular information in living organisms in a non-invasive way. These considerations concern both preclinical research for drug design and human medical applications. With the development of DNA and RNA chips [1], genomics has revolutionised investigative methods for cells and cell processes [2,3]. By sequencing the human genome, new ways have been found for understanding the fundamental mechanisms of life [4]. A revolution is currently under way with the analysis of the proteome [5-8], i.e., the complete set of proteins that can be found in some given biological medium, such as the blood plasma. The goal is to characterise certain diseases by recognisable signatures in the proteomic profile, as determined from a blood sample or a biopsy, for example [9-13]. What is at stake is the early detection of

  14. Information Processing - Administrative Data Processing

    Science.gov (United States)

    Bubenko, Janis

    A three semester, 60-credit course package in the topic of Administrative Data Processing (ADP), offered in 1966 at Stockholm University (SU) and the Royal Institute of Technology (KTH) is described. The package had an information systems engineering orientation. The first semester focused on datalogical topics, while the second semester focused on the infological topics. The third semester aimed to deepen the students’ knowledge in different parts of ADP and at writing a bachelor thesis. The concluding section of this paper discusses various aspects of the department’s first course effort. The course package led to a concretisation of our discipline and gave our discipline an identity. Our education seemed modern, “just in time”, and well adapted to practical needs. The course package formed the first concrete activity of a group of young teachers and researchers. In a forty-year perspective, these people have further developed the department and the topic to an internationally well-reputed body of knowledge and research. The department has produced more than thirty professors and more than one hundred doctoral degrees.

  15. 太阳能集热技术在褐煤干燥工艺上应用的研究%Application and Study on Heat Collection Technology from Sun Energy in Lignite Drying Process

    Institute of Scientific and Technical Information of China (English)

    崔意华; 杨会民

    2013-01-01

    简述了褐煤应用技术的现状;借助Aspen plus软件模拟了褐煤干燥脱水工艺;提出了将太阳能集热技术与褐煤干燥技术耦合的技术思想和工艺流程。研究结果表明,该耦合技术具有节能降耗、环境友好、可就地生产的特点。%Author has briefly described the present situation of lignite application technology; has simulated the dry/dewater process of lignite by means of Aspen plus software; has supposed the technical idea taking the heat collection technology of sun energy coupled with the lignite dry technology and the process flow.Research result indicates that this coupling technology has the features of saving energy and reducing consume , friendly environ-ment, local production.

  16. Historical geomorphic analysis (1932-2011) of a by-passed river reach in process-based restoration perspectives: The Old Rhine downstream of the Kembs diversion dam (France, Germany)

    Science.gov (United States)

    Arnaud, F.; Piégay, H.; Schmitt, L.; Rollet, A. J.; Ferrier, V.; Béal, D.

    2015-05-01

    The Old Rhine downstream of the Kembs diversion dam is one of the largest by-passed river reaches in the world (50 km). It offers a unique opportunity to study the morphological effects of by-passing and address physical and ecological restoration approaches in regulated rivers. We conduct a space-time analysis of channel adjustment over a period of 80 years (1932 to 2011). We examine planform changes (from aerial photographs), erosional and depositional patterns (from vertical profiles), sediment sizes within the active channel and the new established floodplain, and we date riparian vegetation encroachment. Results show that the Old Rhine exhibited rapid response to the completion of the by-passing scheme in the 1950s, with a 26% narrowing in median active channel width between 1956 and 2008, from vegetation encroachment on dewatered channel margins (mostly groyne fields). The narrowing was accompanied by overbank fine sediment deposition (~ 1.5 cm y- 1 aggradation since 1950) as well as slight bed degradation (~ 0.7 cm y- 1 since 1950). We found no downstream propagation of active channel narrowing over time, nor propagation of bed degradation. The channel was already significantly adjusted prior to the diversion scheme, following the nineteenth century river straightening and groyne construction. By-passing (dewatering) mainly provided new pioneer habitat for synchronous vegetation establishment and promoted channel stability by decreasing sediment transport owing to peak flow reduction. The morphological budget calculated over the past 20 years estimated a downstream output for coarse sediments at 16,000 m3 y- 1, with 80% originating from bed degradation and 20% from bank erosion, without significant inputs from upstream. The present-day morphodynamics remain sensitive to changes because of dynamic bed armouring (strategies for altered rivers. Recommended activities are gravel reintroduction with particle-sizes finer than the armoured river bed to enhance

  17. Electrotechnologies to process foods

    Science.gov (United States)

    Electrical energy is being used to process foods. In conventional food processing plants, electricity drives mechanical devices and controls the degree of process. In recent years, several processing technologies are being developed to process foods directly with electricity. Electrotechnologies use...

  18. Fluid transport processes in the passive margins of the Eastern Mediterranean

    Science.gov (United States)

    Bertoni, Claudia; Foschi, Martino; Cartwright, Joe; Levell, Bruce

    2015-04-01

    We analyse and produce a synoptic model of the different styles of fluid transport occurring in the various passive margin settings in the Eastern Mediterranean. The common tectonic-stratigraphic setting is dominated, from the Mesozoic, by the interaction of the Tethyan platforms with Cenozoic to recent, mainly clastic, deposits interacting with the ubiquitous thick late Miocene (Messinian) evaporitic sediments. This created different specific modes of fluid-lithology coupling behaviours, and generated an extraordinary suite of seismically resolvable fluid flow phenomena, including mud volcanoes, pockmarks, dissolution/collapse structures, chimneys and pipes. We integrate this evidence with the analysis of the regional pressure/temperature gradient, and with published hydrocarbon generation models, to propose a regional synthesis of all fluid transport processes in a specific basinal context. We place the fluid flow evidence observed in the Eastern Mediterranean in the framework of the three main fluid flow settings, which are typically defined in sedimentary basins, in terms of depth: 1) A thermobaric fluid regime, where fluid transport is limited and convection can be the dominant transport mechanism, 2) A thermogenic regime, where fluids supplied by hydrocarbon generation can migrate by hydraulic fracturing and advection (along open faults/conduits), by matrix flow and in the longer term, by diffusion processes, 3) A shallow compactional regime, where the fluids are generated by sediment dewatering and shallow diagenesis, and the main transport mechanism is characterised by vertical fluid flow, either through advection and hydrofracturing along faults, or matrix flow. In the Eastern Mediterranean passive margins, this depth-related subdivision needs to be modified in order to accommodate the influence of the laterally and vertically extensive evaporitic series, which acts as a regional aquitard/aquiclude to water or a seal to hydrocarbon flow. The presence of

  19. Wastewater engineering applications of BioIronTech process based on the biogeochemical cycle of iron bioreduction and (biooxidation

    Directory of Open Access Journals (Sweden)

    Volodymyr Ivanov

    2014-12-01

    Full Text Available Bioreduction of Fe(III and biooxidation of Fe(II can be used in wastewater engineering as an innovative biotechnology BioIronTech, which is protected for commercial applications by US patent 7393452 and Singapore patent 106658 “Compositions and methods for the treatment of wastewater and other waste”. The BioIronTech process comprises the following steps: 1 anoxic bacterial reduction of Fe(III, for example in iron ore powder; 2 surface renovation of iron ore particles due to the formation of dissolved Fe2+ ions; 3 precipitation of insoluble ferrous salts of inorganic anions (phosphate or organic anions (phenols and organic acids; 4 (biooxidation of ferrous compunds with the formation of negatively, positively, or neutrally charged ferric hydroxides, which are good adsorbents of many pollutants; 5 disposal or thermal regeration of ferric (hydroxide. Different organic substances can be used as electron donors in bioreduction of Fe(III. Ferrous ions and fresh ferrous or ferric hydroxides that are produced after iron bioreduction and (biooxidation adsorb and precipitate diferent negatively charged molecules, for example chlorinated compounds of sucralose production wastewater or other halogenated organics, as well as phenols, organic acids, phosphate, and sulphide. Reject water (return liquor from the stage of sewage sludge dewatering on municipal wastewater treatment plants represents from 10 to 50% of phosphorus load when being recycled to the aeration tank. BioIronTech process can remove/recover more than 90% of phosphorous from this reject water thus replacing the conventional process of phosphate precipitation by ferric/ferrous salts, which are 20–100 times more expensive than iron ore, which is used in BioIronTech process. BioIronTech process can remarkably improve the aerobic and anaerobic treatments of municipal and industrial wastewaters, especially anaerobic digestion of lipid- and sulphate-containing food-processing wastewater. It

  20. Studies on process synthesis and process integration

    OpenAIRE

    Fien, Gert-Jan A. F.

    1994-01-01

    This thesis discusses topics in the field of process engineering that have received much attention over the past twenty years: (1) conceptual process synthesis using heuristic shortcut methods and (2) process integration through heat-exchanger networks and energy-saving power and refrigeration systems. The shortcut methods for conceptual process synthesis presented in Chapter 2, utilize Residue Curve Maps in ternary diagrams and are illustrated with examples of processes...

  1. Extensible packet processing architecture

    Science.gov (United States)

    Robertson, Perry J.; Hamlet, Jason R.; Pierson, Lyndon G.; Olsberg, Ronald R.; Chun, Guy D.

    2013-08-20

    A technique for distributed packet processing includes sequentially passing packets associated with packet flows between a plurality of processing engines along a flow through data bus linking the plurality of processing engines in series. At least one packet within a given packet flow is marked by a given processing engine to signify by the given processing engine to the other processing engines that the given processing engine has claimed the given packet flow for processing. A processing function is applied to each of the packet flows within the processing engines and the processed packets are output on a time-shared, arbitered data bus coupled to the plurality of processing engines.

  2. Extensible packet processing architecture

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Perry J.; Hamlet, Jason R.; Pierson, Lyndon G.; Olsberg, Ronald R.; Chun, Guy D.

    2013-08-20

    A technique for distributed packet processing includes sequentially passing packets associated with packet flows between a plurality of processing engines along a flow through data bus linking the plurality of processing engines in series. At least one packet within a given packet flow is marked by a given processing engine to signify by the given processing engine to the other processing engines that the given processing engine has claimed the given packet flow for processing. A processing function is applied to each of the packet flows within the processing engines and the processed packets are output on a time-shared, arbitered data bus coupled to the plurality of processing engines.

  3. Pilot Plant Demonstration of a Sulfide Precipitation Process for Metal-Finishing Wastewater Treatment.

    Science.gov (United States)

    1984-05-01

    TOAD Metal-Finishing Wastewater Treatment System 6 3 View of Portion of Treatment System 7 4 Section of Treatment System, Showing Clearwell 7 5 Filter... Clearwell Effluent Suspended Solids 21 10 Effluent Oil and Grease 22 1 1 Dewatered Sludge Solids 23 12 Operating Time, Wastewater Flows, and Volume of...showing clearwell . S S S - - - - - - - - - - S 0C C0 CL U. * 4 Figure 6. Control panel. c. Flow Equalization. The effluents from the cyanide

  4. Process mineralogy IX

    Energy Technology Data Exchange (ETDEWEB)

    Petruk, W.; Hagni, R.D.; Pignolet-Brandom, S.; Hausen, D.M. (eds.) (Canada Centre for Mineral and Energy Technology, Ottawa, ON (Canada))

    1990-01-01

    54 papers are presented under the headings: keynote address; process mineralogy applications to mineral processing; process mineralogy applications to gold; process mineralogy applications to pyrometallurgy and hydrometallurgy; process mineralogy applications to environment and health; and process mineralogy applications to synthetic materials. Subject and author indexes are provided. Three papers have been abstracted separately.

  5. Refactoring Process Models in Large Process Repositories.

    NARCIS (Netherlands)

    Weber, B.; Reichert, M.U.

    2008-01-01

    With the increasing adoption of process-aware information systems (PAIS), large process model repositories have emerged. Over time respective models have to be re-aligned to the real-world business processes through customization or adaptation. This bears the risk that model redundancies are introdu

  6. Thinning spatial point processes into Poisson processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Schoenberg, Frederic Paik

    2010-01-01

    are identified, and where we simulate backwards and forwards in order to obtain the thinned process. In the case of a Cox process, a simple independent thinning technique is proposed. In both cases, the thinning results in a Poisson process if and only if the true Papangelou conditional intensity is used, and...

  7. Thinning spatial point processes into Poisson processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Schoenberg, Frederic Paik

    , and where one simulates backwards and forwards in order to obtain the thinned process. In the case of a Cox process, a simple independent thinning technique is proposed. In both cases, the thinning results in a Poisson process if and only if the true Papangelou conditional intensity is used, and thus can...

  8. Refactoring Process Models in Large Process Repositories.

    NARCIS (Netherlands)

    Weber, B.; Reichert, M.U.

    With the increasing adoption of process-aware information systems (PAIS), large process model repositories have emerged. Over time respective models have to be re-aligned to the real-world business processes through customization or adaptation. This bears the risk that model redundancies are

  9. The permanental process

    DEFF Research Database (Denmark)

    McCullagh, Peter; Møller, Jesper

    2006-01-01

    We extend the boson process first to a large class of Cox processes and second to an even larger class of infinitely divisible point processes. Density and moment results are studied in detail. These results are obtained in closed form as weighted permanents, so the extension i called a permanental...... process. Temporal extensions and a particularly tractable case of the permanental process are also studied. Extensions of the fermion process along similar lines, leading to so-called determinantal processes, are discussed....

  10. Food Processing and Allergenicity

    NARCIS (Netherlands)

    Verhoeckx, K.; Vissers, Y.; Baumert, J.L.; Faludi, R.; Fleys, M.; Flanagan, S.; Herouet-Guicheney, C.; Holzhauser, T.; Shimojo, R.; Bolt, van der Nieke; Wichers, H.J.; Kimber, I.

    2015-01-01

    Food processing can have many beneficial effects. However, processing may also alter the allergenic properties of food proteins. A wide variety of processing methods is available and their use depends largely on the food to be processed.

    In this review the impact of processing (heat and non

  11. Food processing and allergenicity

    NARCIS (Netherlands)

    Verhoeckx, K.C.M.; Vissers, Y.M.; Baumert, J.L.; Faludi, R.; Feys, M.; Flanagan, S.; Herouet-Guicheney, C.; Holzhauser, T.; Shimojo, R.; Bolt, N. van der; Wichers, H.; Kimber, I.

    2015-01-01

    Food processing can have many beneficial effects. However, processing may also alter the allergenic properties of food proteins. A wide variety of processing methods is available and their use depends largely on the food to be processed. In this review the impact of processing (heat and non-heat tre

  12. SAR processing using SHARC signal processing systems

    Science.gov (United States)

    Huxtable, Barton D.; Jackson, Christopher R.; Skaron, Steve A.

    1998-09-01

    Synthetic aperture radar (SAR) is uniquely suited to help solve the Search and Rescue problem since it can be utilized either day or night and through both dense fog or thick cloud cover. Other papers in this session, and in this session in 1997, describe the various SAR image processing algorithms that are being developed and evaluated within the Search and Rescue Program. All of these approaches to using SAR data require substantial amounts of digital signal processing: for the SAR image formation, and possibly for the subsequent image processing. In recognition of the demanding processing that will be required for an operational Search and Rescue Data Processing System (SARDPS), NASA/Goddard Space Flight Center and NASA/Stennis Space Center are conducting a technology demonstration utilizing SHARC multi-chip modules from Boeing to perform SAR image formation processing.

  13. System-dependent dispersion coefficients for the DFT-D3 treatment of adsorption processes on ionic surfaces.

    Science.gov (United States)

    Ehrlich, Stephan; Moellmann, Jonas; Reckien, Werner; Bredow, Thomas; Grimme, Stefan

    2011-12-09

    Dispersion-corrected density functional theory calculations (DFT-D3) were performed for the adsorption of CO on MgO and C(2) H(2) on NaCl surfaces. An extension of our non-empirical scheme for the computation of atom-in-molecules dispersion coefficients is proposed. It is based on electrostatically embedded M(4)X(4) (M=Na, Mg) clusters that are used in TDDFT calculations of dynamic dipole polarizabilities. We find that the C(MM)(6) dispersion coefficients for bulk NaCl and MgO are reduced by factors of about 100 and 35 for Na and Mg, respectively, compared to the values of the free atoms. These are used in periodic DFT calculations with the revPBE semi-local density functional. As demonstrated by calculations of adsorption potential energy curves, the new C(6) coefficients lead to much more accurate energies (E(ads)) and molecule-surface distances than with previous DFT-D schemes. For NaCl/C(2) H(2) we obtained at the revPBE-D3(BJ) level a value of E(ads) =-7.4 kcal mol(-1) in good agreement with experimental data (-5.7 to -7.1 kcal mol(-1)). Dispersion-uncorrected DFT yields an unbound surface state. For the MgO/CO system, the computed revPBE-D3(BJ) value of E(ads) =-4.1 kcal mol(-1) is also in reasonable agreement with experimental results (-3.0 kcal mol(-1)) when thermal corrections are taken into account. Our new dispersion correction also improves computed lattice constants of the bulk systems significantly compared to plain DFT or previous DFT-D results. The extended DFT-D3 scheme also provides accurate non-covalent interactions for ionic systems without empirical adjustments and is suggested as a general tool in surface science.

  14. INTEGRATED RENEWAL PROCESS

    Directory of Open Access Journals (Sweden)

    Suyono .

    2012-07-01

    Full Text Available The marginal distribution of integrated renewal process is derived in this paper. Our approach is based on the theory of point processes, especially Poisson point processes. The results are presented in the form of Laplace transforms.

  15. Integrated Process Capability Analysis

    Institute of Scientific and Technical Information of China (English)

    Chen; H; T; Huang; M; L; Hung; Y; H; Chen; K; S

    2002-01-01

    Process Capability Analysis (PCA) is a powerful too l to assess the ability of a process for manufacturing product that meets specific ations. The larger process capability index implies the higher process yield, a nd the larger process capability index also indicates the lower process expected loss. Chen et al. (2001) has applied indices C pu, C pl, and C pk for evaluating the process capability for a multi-process product wi th smaller-the-better, larger-the-better, and nominal-the-best spec...

  16. Product Development Process Modeling

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The use of Concurrent Engineering and other modern methods of product development and maintenance require that a large number of time-overlapped "processes" be performed by many people. However, successfully describing and optimizing these processes are becoming even more difficult to achieve. The perspective of industrial process theory (the definition of process) and the perspective of process implementation (process transition, accumulation, and inter-operations between processes) are used to survey the method used to build one base model (multi-view) process model.

  17. From Process Understanding to Process Control

    NARCIS (Netherlands)

    Streefland, M.

    2010-01-01

    A licensed pharmaceutical process is required to be executed within the validated ranges throughout the lifetime of product manufacturing. Changes to the process usually require the manufacturer to demonstrate that the safety and efficacy of the product remains unchanged. Recent changes in the regul

  18. Business Process Redesign: Design the Improved Process

    Science.gov (United States)

    1993-09-01

    64 C. MULTIVOTING ......... .................. .. 65 D. ELECTRONIC VOTING TECHNOLOGY ... ......... .. 65 v E. PAIRED...PROCESS IMPROVEMENT PROCESS (PIP) Diagram of each Activity (AI-A4) ......... .. 122 vi APPENDIX D: PRODUCTS AND VENDORS WHICH SUPPORT ELECTRONIC VOTING ............. 126...requirements. D. ELECTRONIC VOTING TECHNOLOGY Nunamaker [1992] suggests that traditional voting usual- ly happens at the end of a discussion, to close

  19. Process Intensification: A Perspective on Process Synthesis

    DEFF Research Database (Denmark)

    Lutze, Philip; Gani, Rafiqul; Woodley, John

    2010-01-01

    In recent years, process intensification (PI) has attracted considerable academic interest as a potential means for process improvement, to meet the increasing demands for sustainable production. A variety of intensified operations developed in academia and industry creates a large number of opti...

  20. Idaho Chemical Processing Plant Process Efficiency improvements

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Technology or Process First?

    DEFF Research Database (Denmark)

    Siurdyban, Artur Henryk; Svejvig, Per; Møller, Charles

    between them using strategic alignment, Enterprise Systems and Business Process Management theories. We argue that the insights from these cases can lead to a better alignment between process and technology. Implications for practice include the direction towards a closer integration of process...... and technology factors in organizations. Theoretical implications call for a design-oriented view of technology and process alignment....

  2. IMPLEMENTING BUSINESS PROCESS MANAGEMENT

    OpenAIRE

    Vlad BALANESCU; Mihaela MASCU

    2014-01-01

    Business Process Management (BPM) is considered to be the third wave in business process theory. Appearing as a response to the critique formulated regarding Business Process Reengineering, BPM tries to be a more holistic and integrated approach to management and processes. In a time where complex solutions are needed solution that incorporates elements from various concepts, Business Process Management can be, in my opinion, a link between these ideas. After a short introduction presenting g...

  3. Thin film processes

    CERN Document Server

    Vossen, John L

    1978-01-01

    Remarkable advances have been made in recent years in the science and technology of thin film processes for deposition and etching. It is the purpose of this book to bring together tutorial reviews of selected filmdeposition and etching processes from a process viewpoint. Emphasis is placed on the practical use of the processes to provide working guidelines for their implementation, a guide to the literature, and an overview of each process.

  4. Business process transformation the process tangram framework

    CERN Document Server

    Sharma, Chitra

    2015-01-01

    This book presents a framework through transformation and explains  how business goals can be translated into realistic plans that are tangible and yield real results in terms of the top line and the bottom line. Process Transformation is like a tangram puzzle, which has multiple solutions yet is essentially composed of seven 'tans' that hold it together. Based on practical experience and intensive research into existing material, 'Process Tangram' is a simple yet powerful framework that proposes Process Transformation as a program. The seven 'tans' are: the transformation program itself, triggers, goals, tools and techniques, culture, communication and success factors. With its segregation into tans and division into core elements, this framework makes it possible to use 'pick and choose' to quickly and easily map an organization's specific requirements. Change management and process modeling are covered in detail. In addition, the book approaches managed services as a model of service delivery, which it ex...

  5. Process innovation laboratory

    DEFF Research Database (Denmark)

    Møller, Charles

    2007-01-01

    Most organizations today are required not only to operate effective business processes but also to allow for changing business conditions at an increasing rate. Today nearly every business relies on their enterprise information systems (EIS) for process integration and future generations of EIS...... will increasingly be driven by business process models. Consequently business process modelling and improvement is becoming a serious challenge. The aim of this paper is to establish a conceptual framework for business process innovation (BPI) in the supply chain based on advanced EIS. The challenge is thus...... to create a new methodology for developing and exploring process models and applications. The paper outlines the process innovation laboratory as a new approach to BPI. The process innovation laboratory is a comprehensive framework and a collaborative workspace for experimenting with process models...

  6. Metallurgical process engineering

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Ruiyu [Central Iron and Steel Research Institute (CISRI), Beijing (China)

    2011-07-01

    ''Metallurgical Process Engineering'' discusses large-scale integrated theory on the level of manufacturing production processes, putting forward concepts for exploring non-equilibrium and irreversible complex system. It emphasizes the dynamic and orderly operation of the steel plant manufacturing process, the major elements of which are the flow, process network and program. The book aims at establishing a quasi-continuous and continuous process system for improving several techno-economic indices, minimizing dissipation and enhancing the market competitiveness and sustainability of steel plants. The book is intended for engineers, researchers and managers in the fields of metallurgical engineering, industrial design, and process engineering. (orig.)

  7. Degradation of organic contaminants with biological aerobic fermentation in activated sludge dewatering and its influencing factors%加工番茄污水污泥生物好氧发酵对有机污染物的降解及其影响因素

    Institute of Scientific and Technical Information of China (English)

    孙世阳

    2015-01-01

    通过研究加工番茄污水污泥的有机污染物降解变化和好氧发酵条件(含水量、pH、C/N、含氧量和CO2)来确定番茄污水中有机污染物降解情况,从而优化加工番茄废水处理。结果表明:最佳生物好氧发酵条件为含水量60%~80%,C/N 范围为5~10,氧气浓度10%,pH=6�5,污泥发酵15 h后,有机物降解速率达到平衡。%We studied the degradation of the organic pollutants in sludge of the waste water from tomato paste processing under aerobic fermentation conditions. The aerobic fermentation parameters were pH, ratio between carbon and nitrogen, oxygen, CO2 , and moisture. The best aerobic fermentation conditions were moisture content between 60% and 80%, ratio between carbon and nitrogen from 5∶1 to 10∶1, oxygen concentration 10% and pH at 6�5. After aerobic fermentation for 15 h, organic contaminants in the sludge decreased obviously.

  8. Acoustic signal processing toolbox for array processing

    Science.gov (United States)

    Pham, Tien; Whipps, Gene T.

    2003-08-01

    The US Army Research Laboratory (ARL) has developed an acoustic signal processing toolbox (ASPT) for acoustic sensor array processing. The intent of this document is to describe the toolbox and its uses. The ASPT is a GUI-based software that is developed and runs under MATLAB. The current version, ASPT 3.0, requires MATLAB 6.0 and above. ASPT contains a variety of narrowband (NB) and incoherent and coherent wideband (WB) direction-of-arrival (DOA) estimation and beamforming algorithms that have been researched and developed at ARL. Currently, ASPT contains 16 DOA and beamforming algorithms. It contains several different NB and WB versions of the MVDR, MUSIC and ESPRIT algorithms. In addition, there are a variety of pre-processing, simulation and analysis tools available in the toolbox. The user can perform simulation or real data analysis for all algorithms with user-defined signal model parameters and array geometries.

  9. Secure Processing Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Secure Processing Lab is the center of excellence for new and novel processing techniques for the formation, calibration and analysis of radar. In addition, this...

  10. Business Process Inventory

    Data.gov (United States)

    Office of Personnel Management — Inventory of maps and descriptions of the business processes of the U.S. Office of Personnel Management (OPM), with an emphasis on the processes of the Office of the...

  11. Radiochemical Processing Laboratory (RPL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Radiochemical Processing Laboratory (RPL)�is a scientific facility funded by DOE to create and implement innovative processes for environmental clean-up and...

  12. Natural Language Processing.

    Science.gov (United States)

    Chowdhury, Gobinda G.

    2003-01-01

    Discusses issues related to natural language processing, including theoretical developments; natural language understanding; tools and techniques; natural language text processing systems; abstracting; information extraction; information retrieval; interfaces; software; Internet, Web, and digital library applications; machine translation for…

  13. Dairy processing, Improving quality

    NARCIS (Netherlands)

    Smit, G.

    2003-01-01

    This book discusses raw milk composition, production and quality, and reviews developments in processing from hygiene and HACCP systems to automation, high-pressure processing and modified atmosphere packaging.

  14. Group Decision Process Support

    DEFF Research Database (Denmark)

    Gøtze, John; Hijikata, Masao

    1997-01-01

    Introducing the notion of Group Decision Process Support Systems (GDPSS) to traditional decision-support theorists.......Introducing the notion of Group Decision Process Support Systems (GDPSS) to traditional decision-support theorists....

  15. Towards better process understanding

    DEFF Research Database (Denmark)

    Matero, Sanni Elina; van der Berg, Franciscus Winfried J; Poutiainen, Sami

    2013-01-01

    , current best practice to control a typical process is to not allow process-related factors to vary i.e. lock the production parameters. The problem related to the lack of sufficient process understanding is still there: the variation within process and material properties is an intrinsic feature...... and cannot be compensated for with constant process parameters. Instead, a more comprehensive approach based on the use of multivariate tools for investigating processes should be applied. In the pharmaceutical field these methods are referred to as Process Analytical Technology (PAT) tools that aim...... to achieve a thorough understanding and control over the production process. PAT includes the frames for measurement as well as data analyzes and controlling for in-depth understanding, leading to more consistent and safer drug products with less batch rejections. In the optimal situation, by applying...

  16. Cognitive processes in CBT

    NARCIS (Netherlands)

    Becker, E.S.; Vrijsen, J.N.

    2017-01-01

    Automatic cognitive processing helps us navigate the world. However, if the emotional and cognitive interplay becomes skewed, those cognitive processes can become maladaptive and result in psychopathology. Although biases are present in most mental disorders, different disorders are characterized by

  17. Infrared processing of foods

    Science.gov (United States)

    Infrared (IR) processing of foods has been gaining popularity over conventional processing in several unit operations, including drying, peeling, baking, roasting, blanching, pasteurization, sterilization, disinfection, disinfestation, cooking, and popping . It has shown advantages over conventional...

  18. News: Process intensification

    Science.gov (United States)

    Conservation of materials and energy is a major objective to the philosophy of sustainability. Where production processes can be intensified to assist these objectives, significant advances have been developed to assist conservation as well as cost. Process intensification (PI) h...

  19. Polyamines in tea processing.

    Science.gov (United States)

    Palavan-Unsal, Narcin; Arisan, Elif Damla; Terzioglu, Salih

    2007-06-01

    The distribution of dietary polyamines, putrescine, spermidine and spermine, was determined during processing of Camellia sinensis. Black tea manufacture is carried by a series of processes on fresh tea leaves involving withering, rolling, fermentation, drying and sieving. The aim of this research was to determine the effect of tea processing on the polyamine content in relation with antioxidant enzymes, superoxide dismutase, lipid peroxidase and glutathione peroxidase. Before processing, the spermine content was much higher than the putrescine and spermidine content in green tea leaves. Spermine was significantly decreased during processing while the putrescine and spermine contents increased during withered and rolling and decreased in the following stages. The superoxide dismutase activity increased at the withering stage and declined during processing. The transcript level of the polyamine biosynthesis-responsible enzyme ornithine decarboxylase was reduced during each processing step. This study reveals the importance of protection of nutritional compounds that are essential for health during the manufacturing process.

  20. Drug Development Process

    Science.gov (United States)

    ... Device Approvals The Drug Development Process The Drug Development Process Share Tweet Linkedin Pin it More sharing ... Pin it Email Print Step 1 Discovery and Development Discovery and Development Research for a new drug ...

  1. Stochastic processes - quantum physics

    Energy Technology Data Exchange (ETDEWEB)

    Streit, L. (Bielefeld Univ. (Germany, F.R.))

    1984-01-01

    The author presents an elementary introduction to stochastic processes. He starts from simple quantum mechanics and considers problems in probability, finally presenting quantum dynamics in terms of stochastic processes.

  2. Software Process Improvement Defined

    DEFF Research Database (Denmark)

    Aaen, Ivan

    2002-01-01

    This paper argues in favor of the development of explanatory theory on software process improvement. The last one or two decades commitment to prescriptive approaches in software process improvement theory may contribute to the emergence of a gulf dividing theorists and practitioners....... It is proposed that this divide be met by the development of theory evaluating prescriptive approaches and informing practice with a focus on the software process policymaking and process control aspects of improvement efforts...

  3. Software Process Improvement Defined

    DEFF Research Database (Denmark)

    Aaen, Ivan

    2002-01-01

    This paper argues in favor of the development of explanatory theory on software process improvement. The last one or two decades commitment to prescriptive approaches in software process improvement theory may contribute to the emergence of a gulf dividing theorists and practitioners....... It is proposed that this divide be met by the development of theory evaluating prescriptive approaches and informing practice with a focus on the software process policymaking and process control aspects of improvement efforts...

  4. Dosimetry for radiation processing

    DEFF Research Database (Denmark)

    Miller, Arne

    1986-01-01

    During the past few years significant advances have taken place in the different areas of dosimetry for radiation processing, mainly stimulated by the increased interest in radiation for food preservation, plastic processing and sterilization of medical products. Reference services both...... and sterilization dosimetry, optichromic dosimeters in the shape of small tubes for food processing, and ESR spectroscopy of alanine for reference dosimetry. In this paper the special features of radiation processing dosimetry are discussed, several commonly used dosimeters are reviewed, and factors leading...

  5. Modeling multiphase materials processes

    CERN Document Server

    Iguchi, Manabu

    2010-01-01

    ""Modeling Multiphase Materials Processes: Gas-Liquid Systems"" describes the methodology and application of physical and mathematical modeling to multi-phase flow phenomena in materials processing. The book focuses on systems involving gas-liquid interaction, the most prevalent in current metallurgical processes. The performance characteristics of these processes are largely dependent on transport phenomena. This volume covers the inherent characteristics that complicate the modeling of transport phenomena in such systems, including complex multiphase structure, intense turbulence, opacity of

  6. Grind hardening process

    CERN Document Server

    Salonitis, Konstantinos

    2015-01-01

    This book presents the grind-hardening process and the main studies published since it was introduced in 1990s.  The modelling of the various aspects of the process, such as the process forces, temperature profile developed, hardness profiles, residual stresses etc. are described in detail. The book is of interest to the research community working with mathematical modeling and optimization of manufacturing processes.

  7. Semisolid Metal Processing Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Apelian,Diran

    2002-01-10

    Mathematical modeling and simulations of semisolid filling processes remains a critical issue in understanding and optimizing the process. Semisolid slurries are non-Newtonian materials that exhibit complex rheological behavior. There the way these slurries flow in cavities is very different from the way liquid in classical casting fills cavities. Actually filling in semisolid processing is often counter intuitive

  8. Clinical Process Intelligence

    DEFF Research Database (Denmark)

    Vilstrup Pedersen, Klaus

    2006-01-01

    .e. local guidelines. From a knowledge management point of view, this externalization of generalized processes, gives the opportunity to learn from, evaluate and optimize the processes. "Clinical Process Intelligence" (CPI), will denote the goal of getting generalized insight into patient centered health...

  9. Auditory processing models

    DEFF Research Database (Denmark)

    Dau, Torsten

    2008-01-01

    The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook will pr...

  10. Teaching Process Design through Integrated Process Synthesis

    Science.gov (United States)

    Metzger, Matthew J.; Glasser, Benjamin J.; Patel, Bilal; Hildebrandt, Diane; Glasser, David

    2012-01-01

    The design course is an integral part of chemical engineering education. A novel approach to the design course was recently introduced at the University of the Witwatersrand, Johannesburg, South Africa. The course aimed to introduce students to systematic tools and techniques for setting and evaluating performance targets for processes, as well as…

  11. Thin film processes II

    CERN Document Server

    Kern, Werner

    1991-01-01

    This sequel to the 1978 classic, Thin Film Processes, gives a clear, practical exposition of important thin film deposition and etching processes that have not yet been adequately reviewed. It discusses selected processes in tutorial overviews with implementation guide lines and an introduction to the literature. Though edited to stand alone, when taken together, Thin Film Processes II and its predecessor present a thorough grounding in modern thin film techniques.Key Features* Provides an all-new sequel to the 1978 classic, Thin Film Processes* Introduces new topics, and sever

  12. Silicon production process evaluations

    Science.gov (United States)

    1982-01-01

    Chemical engineering analyses involving the preliminary process design of a plant (1,000 metric tons/year capacity) to produce silicon via the technology under consideration were accomplished. Major activities in the chemical engineering analyses included base case conditions, reaction chemistry, process flowsheet, material balance, energy balance, property data, equipment design, major equipment list, production labor and forward for economic analysis. The process design package provided detailed data for raw materials, utilities, major process equipment and production labor requirements necessary for polysilicon production in each process.

  13. Data processing made simple

    CERN Document Server

    Wooldridge, Susan

    2013-01-01

    Data Processing: Made Simple, Second Edition presents discussions of a number of trends and developments in the world of commercial data processing. The book covers the rapid growth of micro- and mini-computers for both home and office use; word processing and the 'automated office'; the advent of distributed data processing; and the continued growth of database-oriented systems. The text also discusses modern digital computers; fundamental computer concepts; information and data processing requirements of commercial organizations; and the historical perspective of the computer industry. The

  14. Biomass process handbook

    Energy Technology Data Exchange (ETDEWEB)

    1983-01-01

    Descriptions are given of 42 processes which use biomass to produce chemical products. Marketing and economic background, process description, flow sheets, costs, major equipment, and availability of technology are given for each of the 42 processes. Some of the chemicals discussed are: ethanol, ethylene, acetaldehyde, butanol, butadiene, acetone, citric acid, gluconates, itaconic acid, lactic acid, xanthan gum, sorbitol, starch polymers, fatty acids, fatty alcohols, glycerol, soap, azelaic acid, perlargonic acid, nylon-11, jojoba oil, furfural, furfural alcohol, tetrahydrofuran, cellulose polymers, products from pulping wastes, and methane. Processes include acid hydrolysis, enzymatic hydrolysis, fermentation, distillation, Purox process, and anaerobic digestion.

  15. Colloid process engineering

    CERN Document Server

    Peukert, Wolfgang; Rehage, Heinz; Schuchmann, Heike

    2015-01-01

    This book deals with colloidal systems in technical processes and the influence of colloidal systems by technical processes. It explores how new measurement capabilities can offer the potential for a dynamic development of scientific and engineering, and examines the origin of colloidal systems and its use for new products. The future challenges to colloidal process engineering are the development of appropriate equipment and processes for the production and obtainment of multi-phase structures and energetic interactions in market-relevant quantities. The book explores the relevant processes and for controlled production and how they can be used across all scales.

  16. Process-based costing.

    Science.gov (United States)

    Lee, Robert H; Bott, Marjorie J; Forbes, Sarah; Redford, Linda; Swagerty, Daniel L; Taunton, Roma Lee

    2003-01-01

    Understanding how quality improvement affects costs is important. Unfortunately, low-cost, reliable ways of measuring direct costs are scarce. This article builds on the principles of process improvement to develop a costing strategy that meets both criteria. Process-based costing has 4 steps: developing a flowchart, estimating resource use, valuing resources, and calculating direct costs. To illustrate the technique, this article uses it to cost the care planning process in 3 long-term care facilities. We conclude that process-based costing is easy to implement; generates reliable, valid data; and allows nursing managers to assess the costs of new or modified processes.

  17. Dynamical laser spike processing

    CERN Document Server

    Shastri, Bhavin J; Tait, Alexander N; Rodriguez, Alejandro W; Wu, Ben; Prucnal, Paul R

    2015-01-01

    Novel materials and devices in photonics have the potential to revolutionize optical information processing, beyond conventional binary-logic approaches. Laser systems offer a rich repertoire of useful dynamical behaviors, including the excitable dynamics also found in the time-resolved "spiking" of neurons. Spiking reconciles the expressiveness and efficiency of analog processing with the robustness and scalability of digital processing. We demonstrate that graphene-coupled laser systems offer a unified low-level spike optical processing paradigm that goes well beyond previously studied laser dynamics. We show that this platform can simultaneously exhibit logic-level restoration, cascadability and input-output isolation---fundamental challenges in optical information processing. We also implement low-level spike-processing tasks that are critical for higher level processing: temporal pattern detection and stable recurrent memory. We study these properties in the context of a fiber laser system, but the addit...

  18. Cell abundance and microbial community composition along a complete oil sand mining and reclamation process

    Science.gov (United States)

    Lappé, M.; Schneider, B.; Kallmeyer, J.

    2012-12-01

    Hydrocarbons constitute an important energy source for microbes but can also be of environmental concern. Microbial activity causes hydrocarbon degradation and thereby loss of economical value, but also helps to remove hydrocarbons from the environment. The present study characterizes the abundance of microbes along the oil sand mining process in Alberta, Canada, as a first approach to assess the impact of mining and oil extraction on the microbial population. After mining the oil is extracted from the sediment by a hot-water extraction (50-60°C), resulting in three major fractions: crude oil, tailings sand and fine tailings. The tailings sand is used as substratum for newly developing soils on the reclamation areas. The very liquid fine tailings still have a TOC content of about 4.3% and are pumped into tailings ponds, where they need up to three decades to settle and solidify. After deposition, these mature fine tailings (MFTs) are enriched in organics (TOC content between 9.6 and 16.8%) and dredged out of the ponds and put on dumps for several years for dewatering. Finally they are brought out onto the reclamation sites and deposited below the sand layer. Cells were extracted from oily sediments according to the protocol of Lappé and Kallmeyer (2011), stained with SYBR Green I and counted by fluorescence microscopy. Cell abundance in the unprocessed oil sand is around 1.6 x 107 cells cm-3. After processing the fresh fine tailings still contain around 1.6 x 107 cells cm-3. Cell counts in the processed MFTs are 5.8 x 107 cells cm-3, whereas in the sand used as substratum for newly developing soils, they are twice as high (1.4 x 108). In root-bearing horizons, cell counts reach 1.1 x 109 cell cm-3. Cell numbers calculated from cultivation experiments are in the same range. Higher cell counts in the tailings sand are probably due to a higher nitrogen supply through the addition of a 35 cm top layer of a peat-mineral mix. In the sand nitrate concentrations are high

  19. A secondary fuel removal process: plasma processing

    Energy Technology Data Exchange (ETDEWEB)

    Min, J. Y.; Kim, Y. S. [Hanyang Univ., Seoul (Korea, Republic of); Bae, K. K.; Yang, M. S. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-07-01

    Plasma etching process of UO{sub 2} by using fluorine containing gas plasma is studied as a secondary fuel removal process for DUPIC (Direct Use of PWR spent fuel Into Candu) process which is taken into consideration for potential future fuel cycle in Korea. CF{sub 4}/O{sub 2} gas mixture is chosen for reactant gas and the etching rates of UO{sub 2} by the gas plasma are investigated as functions of CF{sub 4}/O{sub 2} ratio, plasma power, substrate temperature, and plasma gas pressure. It is found that the optimum CF{sub 4}/O{sub 2} ratio is around 4:1 at all temperatures up to 400 deg C and the etching rate increases with increasing r.f. power and substrate temperature. Under 150W r.f. power the etching rate reaches 1100 monolayers/min at 400 deg C, which is equivalent to about 0.5mm/min. (author).

  20. Pultrusion process characterization

    Science.gov (United States)

    Vaughan, James G.; Hackett, Robert M.

    1991-01-01

    Pultrusion is a process through which high-modulus, lightweight composite structural members such as beams, truss components, stiffeners, etc., are manufactured. The pultrusion process, though a well-developed processing art, lacks a fundamental scientific understanding. The objective here was to determine, both experimentally and analytically, the process parameters most important in characterizing and optimizing the pultrusion of uniaxial fibers. The effects of process parameter interactions were experimentally examined as a function of the pultruded product properties. A numerical description based on these experimental results was developed. An analytical model of the pultrusion process was also developed. The objective of the modeling effort was the formulation of a two-dimensional heat transfer model and development of solutions for the governing differential equations using the finite element method.