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Sample records for waste activated bleaching

  1. Enhancement of lipase catalyzed-fatty acid methyl esters production from waste activated bleaching earth by nullification of lipase inhibitors.

    Dwiarti, Lies; Ali, Ehsan; Park, Enoch Y

    2010-01-01

    This study sought to identify inhibitory factors of lipase catalyzed-fatty acid methyl esters (FAME) production from waste activated bleaching earth (wABE). During the vegetable oil refinery process, activated bleaching earth (ABE) is used for removing the impure compounds, but adsorbs vegetable oil up to 35-40% as on a weight basis, and then the wABE is discarded as waste material. The impurities were extracted from the wABE with methanol and evaluated by infra-red (IR) spectroscopy, which revealed that some were chlorophyll-plant pigments. The chlorophylls inhibited the lipase during FAME conversion from wABE. The inhibition by a mixture of chlorophyll a and b was found to be competitive. The inhibition of the enzymatic hydrolysis of waste vegetable oil contained in wABE by chlorophyll a alone was competitive, while the inhibition by chlorophyll b alone was non-competitive. Furthermore, the addition of a small amount of alkali nullified this inhibitory effect and accelerated the FAME production rate. When 0.9% KOH (w/w wABE) was added to the transesterification reaction with only 0.05% lipase (w/w wABE), the maximum FAME production rate improved 120-fold, as compared to that without the addition of KOH. The alkali-combined lipase significantly enhanced the FAME production rate from wABE, in spite of the presence of the plant pigments, and even when a lower amount of lipase was used as a catalyst.

  2. Efficient production of fatty acid methyl ester from waste activated bleaching earth using diesel oil as organic solvent.

    Kojima, Seiji; Du, Dongning; Sato, Masayasu; Park, Enoch Y

    2004-01-01

    Fatty acid methyl ester (FAME) production from waste activated bleaching earth (ABE) discarded by the crude oil refining industry was investigated using fossil fuel as a solvent in the esterification of triglycerides. Lipase from Candida cylindracea showed the highest stability in diesel oil. Using diesel oil as a solvent, 3 h was sufficient to obtain a yield of approximately 100% of FAME in the presence of 10% lipase from waste ABE. Kerosene was also a good solvent in the esterification of triglycerides embedded in the waste ABE. Fuel analysis showed that the FAME produced using diesel oil as a solvent complied with the Japanese diesel standard and the 10% residual carbon amount was lower than that of FAME produced using other solvents. Use of diesel oil as solvent in the FAME production from the waste ABE simplified the process, because there was no need to separate the organic solvent from the FAME-solvent mixture. These results demonstrate a promising reutilization method for the production of FAME, for use as a biodiesel, from industrial waste resources containing waste vegetable oils.

  3. Lipase-catalyzed biodiesel production from waste activated bleaching earth as raw material in a pilot plant.

    Park, Enoch Y; Sato, Masayasu; Kojima, Seiji

    2008-05-01

    The production of fatty acid methyl esters (FAMEs) from waste activated bleaching earth (ABE) discarded by the crude oil refining industry using lipase from Candida cylindracea was investigated in a 50-L pilot plant. Diesel oil or kerosene was used as an organic solvent for the transesterification of triglycerides embedded in the waste ABE. When 1% (w/w) lipase was added to waste ABE, the FAME content reached 97% (w/w) after reaction for 12 h at 25 degrees C with an agitation rate of 30 rpm. The FAME production rate was strongly dependent upon the amount of enzyme added. Mixtures of FAME and diesel oil at ratios of 45:55 (BDF-45) and 35:65 (BDF-35) were assessed and compared with the European specifications for biodiesel as automotive diesel fuel, as defined by pr EN 14214. The biodiesel quality of BDF-45 met the EN 14214 standard. BDF-45 was used as generator fuel, and the exhaust emissions were compared with those of diesel oil. The CO and SO2 contents were reduced, but nitrogen oxide emission increased by 10%. This is the first report of a pilot plant study of lipase-catalyzed FAME production using waste ABE as a raw material. This result demonstrates a promising reutilization method for the production of FAME from industrial waste resources containing vegetable oils for use as a biodiesel fuel.

  4. Bleaching of cotton fabric with tetraacetylhydrazine as bleach activator for H2O2.

    Liu, Kai; Zhang, Xuan; Yan, Kelu

    2018-05-15

    Tetraacetylhydrazine (TH) as bleach activator for H 2 O 2 cotton bleaching was synthesized and characterized by 1 H NMR, 13 C NMR and MS spectra. TH has better solubility than that of TAED. The CIE whiteness index (WI), H 2 O 2 decomposition rate and bursting strength were employed to investigate the performance of H 2 O 2 /TH bleaching system. By addition of TH, WI and H 2 O 2 decomposition rate increased significantly at 70 °C. Bleaching temperature, NaHCO 3 concentration and bleaching time were also discussed in detail and the loss of bursting strength is not clear. By using benzenepentacarboxylic acid (BA) as a fluorescent probe for hydroxyl radical detection, the bleaching process of H 2 O 2 /TH system was investigated. Acetylhydrazine and diacetylhydrazine were also utilized to further confirm the process. In addition, bimolecular decomposition was investigated by using 9,10-dimethylanthracene (DMA) as fluorescent probe of 1 O 2 . Based on these experimental results, the bleaching mechanism of H 2 O 2 /TH system was proposed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. The effect of light-activation sources on tooth bleaching

    Baroudi, Kusai; Hassan, Nadia Aly

    2014-01-01

    Vital bleaching is one of the most requested cosmetic dental procedures asked by patients who seek a more pleasing smile. This procedure consists of carbamide or hydrogen peroxide gel applications that can be applied in-office or by the patient (at-home/overnight bleaching system). Some in-office treatments utilise whitening light with the objective of speeding up the whitening process. The objective of this article is to review and summarise the current literature with regard to the effect of light-activation sources on in-office tooth bleaching. A literature search was conducted using Medline, accessed via the National Library of Medicine Pub Med from 2003 to 2013 searching for articles relating to effectiveness of light activation sources on in-office tooth bleaching. This study found conflicting evidence on whether light truly improve tooth whitening. Other factors such as, type of stain, initial tooth colour and subject age which can influence tooth bleaching outcome were discussed. Conclusions: The use of light activator sources with in-office bleaching treatment of vital teeth did not increase the efficacy of bleaching or accelerate the bleaching. PMID:25298598

  6. PROCESS OPTIMIZATION OF TETRA ACETYL ETHYLENE DIAMINE ACTIVATED HYDROGEN PEROXIDE BLEACHING OF POPULUS NIGRA CTMP

    Qiang Zhao; Junwen Pu; Shulei Mao; Guibo Qi

    2010-01-01

    To enhance the bleaching efficiency, the activator of tetra acetyl ethylene diamine (TAED) was used in conventional H2O2 bleaching. The H2O2/TAED bleaching system can accelerate the reaction rate and shorten bleaching time at relative low temperature, which can reduce the production cost. In this research, the process with hydrogen peroxide activated by TAED bleaching of Populus nigra chemi-thermo mechanical pulp was optimized. Suitable bleaching conditions were confirmed as follows: pulp con...

  7. Coral bleaching independent of photosynthetic activity.

    Tolleter, Dimitri; Seneca, François O; DeNofrio, Jan C; Krediet, Cory J; Palumbi, Stephen R; Pringle, John R; Grossman, Arthur R

    2013-09-23

    The global decline of reef-building corals is due in part to the loss of algal symbionts, or "bleaching," during the increasingly frequent periods of high seawater temperatures. During bleaching, endosymbiotic dinoflagellate algae (Symbiodinium spp.) either are lost from the animal tissue or lose their photosynthetic pigments, resulting in host mortality if the Symbiodinium populations fail to recover. The >1,000 studies of the causes of heat-induced bleaching have focused overwhelmingly on the consequences of damage to algal photosynthetic processes, and the prevailing model for bleaching invokes a light-dependent generation of toxic reactive oxygen species (ROS) by heat-damaged chloroplasts as the primary trigger. However, the precise mechanisms of bleaching remain unknown, and there is evidence for involvement of multiple cellular processes. In this study, we asked the simple question of whether bleaching can be triggered by heat in the dark, in the absence of photosynthetically derived ROS. We used both the sea anemone model system Aiptasia and several species of reef-building corals to demonstrate that symbiont loss can occur rapidly during heat stress in complete darkness. Furthermore, we observed damage to the photosynthetic apparatus under these conditions in both Aiptasia endosymbionts and cultured Symbiodinium. These results do not directly contradict the view that light-stimulated ROS production is important in bleaching, but they do show that there must be another pathway leading to bleaching. Elucidation of this pathway should help to clarify bleaching mechanisms under the more usual conditions of heat stress in the light. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Tooth Whitening And Temperature Rise With Two Bleaching Activation Methods

    Abu-ElMagd, D. M.; El-Sayad, I. I.; Abd El-Gawad, L. M.

    2009-01-01

    To measure the tooth whitening and the surface and Intrapulpal temperature increase in vitro on freshly extracted upper human central incisors after chemical, Zoom AP light and diode laser activated bleaching. Thirty caries-free upper human incisors were selected. Teeth were divided into three equal groups according to the methods of activation of the bleaching agent (n = 10). A whitening gel containing hydrogen peroxide was applied to the buccal surface of all teeth. Group I was bleached using chemically activated hydrogen peroxide gel, for three applications of 15 min each. Group II was bleached with high intensity advanced power Zoom activation light (Zoom AP), for three applications of 15 min each. Group III was bleached with diode laser activation technique, where the teeth were irradiated with 2 Watt diode laser for three applications of 30 sec each. The whitening degree was assessed using an image analysis system, while temperature rise was recorded using a thermocouple on the external tooth surface and Intrapulpal. The degree of whitening increased significantly in all groups. However, the percentage of whitening was not statistically significantly different between the three groups. In addition, group II showed statistically significant higher mean rise in both surface and pulp temperatures than group I and group III. Chemical bleaching produces the same whitening effect as Zoom AP light and laser, with no surface or pulpal temperature rise. Laser application is faster and produces less surface and pulp temperature increase than Zoom AP light. Diode laser used to activate bleaching gels is not considered dangerous to the vitality of dental pulp using power settings of 2 W.

  9. Kraft pulp bleaching with molybdenum activated acid peroxide (PMo stage)

    Rabelo, Marcos Sousa

    2009-01-01

    Optimum conditions to run the P Mo stage for bleaching eucalyptus kraft pulp were 90 deg C, pH 3.5, 2 h, 0.1 kg/t Mo and 5 kg/t H 2 O 2 . The P Mo stage efficiency increased with decreasing pH (1.5-5.5) and increasing temperature (75-90 deg C), time (2-4 h), and hydrogen peroxide (3-10 kg/t) and molybdenum concentration (0.1-0.4 kg/t). The implementation of the P Mo stage, as replacement for the A stage, decreased total active chlorine demand of the OAZDP sequence by 6 kg/t to reach 90% ISO, both in laboratory and mill scale. Such practice resulted in decreased bleaching chemical costs to produce fully bleached pulp of 90% ISO. (author)

  10. Temperature variation in pulp chamber during dental bleaching in presence or absence of light activation

    Mollica, Fernanda Brandão; Rocha, Daniel Maranha da; Travassos, Alessandro Caldas; Valera, Marcia Carneiro; Araujo, Maria Amélia Maximo de

    2010-01-01

    PURPOSE: In addition to the chemical damage due to bleaching gels penetration into the pulp during pulp vitality dental bleaching, another possible aggressive factor could be the heat generated by the exothermal oxidation reaction of the bleaching gel, which may also be aggravated by the use of light activation. This study assessed the temperature variation in the pulp chamber in human teeth, using three different bleaching gels with or without LED light activation. METHODS: Thirty human pre-...

  11. Comparison of Tooth Color Change After Bleaching With Conventional and Different Light-Activated Methods.

    Shahabi, Sima; Assadian, Hadi; Mahmoudi Nahavandi, Alireza; Nokhbatolfoghahaei, Hanieh

    2018-01-01

    Introduction: The demand for esthetic dental treatments is increasing in recent years mainly due to improved oral hygiene and better maintenance of oral health and teeth in older individuals. Bleaching of discolored anterior teeth is the most popular among esthetic dental treatments. Even individuals with sound teeth and adequate esthetics seek to have whiter teeth in the anterior region. The aim of this study was to evaluate tooth color changes following conventional in-office bleaching techniques compared to light-activated methods using different light sources. Methods: Seventy sound anterior teeth (devoided of caries and/or fracture), extracted for periodontal and orthodontic reasons were selected and allocated to 7 groups: (A) control, (B) conventional bleaching (C) LED-activated bleaching, (D) KTP laser-activated bleaching, (E) diode laser-activated bleaching, (F) Nd:YAG laser-activated bleaching and (G) CO2 laser-activated bleaching. Colorimetric evaluation was carried out before and after treatment using a spectrophotoradiometer. Data were analyzed by one- and two-way analysis of variance (ANOVA) as well as multiple comparison methods. Results: The results showed that all bleaching procedures were effective in reducing the yellowness index. However, the KTP laser-activated bleaching was significantly more effective than the other techniques in 95% confidence level. It was also seen that CO2 laser activated method has outperformed groups E, F and G and the conventional bleaching without light activation was not effective at all and represented similar results with the control group. Furthermore, the groups E and G had almost the same results in decreasing the yellowness index. Conclusion: The results showed that all bleaching techniques were effective however, the KTP laser-activated bleaching was significantly more efficient, closely followed by the CO2 laser-activated bleaching technique.

  12. Bleaching of Neutral Cotton Seed Oil Using Organic Activated Carbon in a Batch System: Kinetics and Adsorption Isotherms

    Abba Chetima

    2018-03-01

    Full Text Available In the processing of cotton and neem seeds to obtain oil for diverse uses, enormous quantities of seed husk are generated as waste, which when not properly disposed of, poses environmental problems. One way of reducing this waste is to use it for the production of activated carbon (AC for its multiple applications. In this work, activated carbon was produced from cotton and neem seed husks by carbonization followed by acid activation. The prepared ACs were characterized for its porosity and surface properties as well as for its ability to bleach neutral cotton seed oil. The prepared ACs are very efficient in the decoloration process, as they removed about 96–98% of the pigments compared to 98.4% removal with commercial bleaching earth. Temperature had a pronounced effect on the bleaching of neutral cotton seed oil. Maximum adsorption was observed at 60 °C for a contact time of 45 min. The adsorption kinetics were modelled by the intra-particle and the pseudo-second order equations while the adsorption isotherms followed the Langmuir and Freundlich equations. It is concluded that the organic ACs are efficient in pigment removal from neutral cotton seed oil and therefore are potential bleaching agents for the vegetable oil industry.

  13. Optimization of acid-activated bentonites on bleaching of cotton oil

    Lacin, O.; Sayan, E.; Kirali, E.G.

    2013-01-01

    Bentonites are commonly used adsorbent on bleaching cotton oil to produce edible oil products. Bleaching capacities of neutralized cotton oil were investigated with acid-activated Arguvan and Kursunlu bentonites. Two models for acid activation of the bentonites were developed by using a full factorial experimental design and central composite design. The parameters used to develop these models were contact time, solid to liquid ratio, acid concentration and moisture of bentonite. By using a constrained optimization program, the maximum bleaching capacities of neutralized cotton oil were determined as 99.99% and 48.5% for Arguvan and Kursunlu, respectively. Optimum results showed that Turkish bentonites (especially Arguvan bentonite) have high bleaching ability and they can be used efficiently to bleach neutralized cotton oil by considering the favorable volume weight, capacity of oil adsorbed and filtration rate. (author)

  14. Influence of bleach activators on the fabric made from cotton (gossypium hamster l.)

    Asif, H.M.; Iftikhar, M.; Shahbaz, B.

    2013-01-01

    Raw cotton contains various type of trash and most of the impurities are removed during the spinning process but still the cotton fabric coming from the weaving or knitting process always contains some impurities. Some time cotton fabric gets the oil, stains and coloured materials which affect the quality of dyed fabric. Bleaching is a process that eliminates unwanted coloured matters from the fibres, yarn and fabrics. A bleaching agent is a material that lightens or whitens a substrate through chemical action. Hydrogen peroxide is by far the most commonly used oxidative bleaching agent for cotton and its blends, accounting for more than 90 percent of all the bleaching agents. The use of activators to enhance the bleaching performance of hydrogen peroxide for cellulosic materials has gained popularity now a day. In this context the main objectives of this paper are to study the influence of different bleaching activators on cotton fabric and to give implications for textile extension.The results indicate that the activators with different concentrations, along with different concentrations of hydrogen peroxide (H/sub 2/O/sub 2) have significant influence on the bleaching performance of cotton fabric. (author)

  15. Clinical and Spectrophotometric Evaluation of LED and Laser Activated Teeth Bleaching.

    Lo Giudice, R; Pantaleo, G; Lizio, A; Romeo, U; Castiello, G; Spagnuolo, G; Giudice, G Lo

    2016-01-01

    Auxiliary power sources (LED and laser) are used in in-office teeth bleaching techniques to accelerate the redox reaction of the whitening gel to increase ease of use, to improve comfort and safety, and to decrease the procedure time. The aim this study is to evaluate the efficiency of the teeth whitening procedures performed with hydrogen peroxide and carbamide peroxide, LED or Laser activated. 18 patients, affected by exogenous dyschromia, were treated with a bleaching agent composed by 35% hydrogen peroxide and 10% carbamide peroxide. They were divided into two groups: in the first group the bleaching agent was activated by a LED lamp; in the second group it was activated by a Laser diode lamp. Both groups were subjected to 3 bleaching cycle of 15' each. The chromatic evaluations were performed before and after one week from the treatment, using a chromatic scale and a spectrophotometer. The mean value of pre, post bleaching and follow-up were analyzed using a T-test, with results statistically significant for Pbleaching effectiveness. All patients treated with laser activation complained an increase in dental sensitivity. The use of laser-activating systems did not improve the efficacy of bleaching.

  16. Physicochemical properties and oxidative stability of bleached pomace-olive oil on Tunisian activated clays

    Jahouach, Wafa

    2002-01-01

    This work is a contribution to studying bleaching process, which is an important stage in refining of vegetable oils. This process permitted to reduce or convert undesired constituents to harmless ones from oils and fats. Virgin olive oil, considered as reference, and pomace-olive oil were bleached in optimal conditions using Tunisian activated clays ( collected from the South of Tunisia) which were prepared in our laboratory and compared with commercial bleaching earths. It was shown that activated Tunisian clays are characterized by a very important adsorptive capacity, which is similar to that of commercial ones. In addition, the study of physicochemical properties of bleached oils was considered. The fatty acid composition (GC), the triacylglycerol composition (HPLC), and oxidative stability (UV spectrometry) allowed to conclude that treated oils do not undergo considerable physicochemical alterations and their caracteristics remain in concordance with international standards relative to edible refined oils. (Author)

  17. Effect of bleaching on mercury release from amalgam fillings and antioxidant enzyme activities: a pilot study.

    Cakir, Filiz Yalcin; Ergin, Esra; Gurgan, Sevil; Sabuncuoglu, Suna; Arpa, Cigdem Sahin; Tokgoz, İlknur; Ozgunes, Hilal; Kiremitci, Arlin

    2015-01-01

    The aim of this pilot clinical study was to determine the mercury release from amalgam fillings and antioxidant enzyme activities (Superoxide Dismutase [SOD] and Catalase[CAT] ) in body fluids after exposure to two different vital tooth bleaching systems. Twenty eight subjects with an average age of 25.6 years (18-41) having at least two but not more than four Class II amalgam fillings on each quadrant arch in the mouth participated in the study. Baseline concentrations of mercury levels in whole blood, urine, and saliva were measured by a Vapor Generation Accessory connected to an Atomic Absorption Spectrometer. Erythrocyte enzymes, SOD, and CAT activities in blood were determined kinetically. Subjects were randomly assigned to two groups of 14 volunteers. Group 1 was treated with an at-home bleaching system (Opalescence PF 35% Carbamide Peroxide, Ultradent), and Group 2 was treated with a chemically activated office bleaching system (Opalescence Xtra Boost 38% Hydrogen Peroxide, Ultradent) according to the manufacturer's recommendations. Twenty-four hours after bleaching treatments, concentrations of mercury and enzymes were remeasured. There were no significant differences on mercury levels in blood, urine, and saliva before and after bleaching treatments (p > 0.05). No differences were also found in the level of antioxidant enzyme activities (SOD and CAT) before and after treatments (p > 0.05). Mercury release did not affect the enzyme activities (p > 0.05). Bleaching treatments either office or home did not affect the amount of mercury released from amalgam fillings in blood, urine, and saliva and the antioxidant-enzyme activities in blood. Bleaching treatments with the systems tested in this pilot study have no deleterious effect on the mercury release from amalgam fillings and antioxidant enzymes in body fluids. © 2014 Wiley Periodicals, Inc.

  18. Increased riboflavin production from activated bleaching earth by a mutant strain of Ashbya gossypii.

    Tajima, Satoshi; Itoh, Yoko; Sugimoto, Takashi; Kato, Tatsuya; Park, Enoch Y

    2009-10-01

    The production of riboflavin from vegetable oil was increased using a mutant strain of Ashbya gossypii. This mutant was generated by treating the wild-type strain with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Riboflavin production was 10-fold higher in the mutant compared to the wild-type strain. The specific intracellular catalase activity after 3 d of culture was 6-fold higher in the mutant than in the wild-type strain. For the mutant, riboflavin production in the presence of 40 mM hydrogen peroxide was 16% less than that in the absence of hydrogen peroxide, whereas it was 56% less for the wild-type strain. The isocitrate lyase (ICL) activity of the mutant was 0.26 mU/mg of protein during the active riboflavin production phase, which was 2.6-fold higher than the wild-type strain. These data indicate that the mutant utilizes the carbon flux from the TCA cycle to the glyoxylate cycle more efficiently than the wild-type strain, resulting in enhanced riboflavin production. This novel mutant has the potential to be of use for industrial-scale riboflavin production from waste-activated bleaching earth (ABE), thereby transforming a useless material into a valuable bioproduct.

  19. Two-state model of light induced activation and thermal bleaching of photochromic glasses: theory and experiments

    Ferrari, Jose A.; Perciante, Cesar D.

    2008-01-01

    The behavior of photochromic glasses during activation and bleaching is investigated. A two-state phenomenological model describing light-induced activation (darkening) and thermal bleaching is presented. The proposed model is based on first-order kinetics. We demonstrate that the time behavior in the activation process (acting simultaneously with the thermal fading) can be characterized by two relaxation times that depend on the intensity of the activating light. These characteristic times are lower than the decay times of the pure thermal bleaching process. We study the temporal evolution of the glass optical density and its dependence on the activating intensity. We also present a series of activation and bleaching experiments that validate the proposed model. Our approach may be used to gain more insight into the transmittance behavior of photosensitive glasses, which could be potentially relevant in a broad range of applications, e.g., real-time holography and reconfigurable optical memories

  20. Effects of different activation processes on H2O2/TAED bleaching of Populus nigra chemi-thermo mechanical pulp

    Qiang Zhao; Dezhi Sun; Zhaohong Wang; Junwen Pu; Xiaojuan Jin; Mian Xing

    2012-01-01

    Tetra acetyl ethylene diamine (TAED) was used as an activator in H2O2 bleaching to improve bleaching efficiency. The present work was aimed at confirming different activations for various H2O2/TAED bleaching processes, including the addition of acetic anhydride and the step-addition of sodium hydroxide. The results showed that an acetic anhydride dosage of 1%, an acetic anhydride treatment time of 10 min, and an addition time of 45 min were the optimal treatment conditions. The optimum proces...

  1. Rhythmic ganglion cell activity in bleached and blind adult mouse retinas.

    Menzler, Jacob; Channappa, Lakshmi; Zeck, Guenther

    2014-01-01

    In retinitis pigmentosa--a degenerative disease which often leads to incurable blindness--the loss of photoreceptors deprives the retina from a continuous excitatory input, the so-called dark current. In rodent models of this disease this deprivation leads to oscillatory electrical activity in the remaining circuitry, which is reflected in the rhythmic spiking of retinal ganglion cells (RGCs). It remained unclear, however, if the rhythmic RGC activity is attributed to circuit alterations occurring during photoreceptor degeneration or if rhythmic activity is an intrinsic property of healthy retinal circuitry which is masked by the photoreceptor's dark current. Here we tested these hypotheses by inducing and analysing oscillatory activity in adult healthy (C57/Bl6) and blind mouse retinas (rd10 and rd1). Rhythmic RGC activity in healthy retinas was detected upon partial photoreceptor bleaching using an extracellular high-density multi-transistor-array. The mean fundamental spiking frequency in bleached retinas was 4.3 Hz; close to the RGC rhythm detected in blind rd10 mouse retinas (6.5 Hz). Crosscorrelation analysis of neighbouring wild-type and rd10 RGCs (separation distance rhythmic RGC spiking in these retinas is driven by a network of presynaptic neurons. The inhibition of glutamatergic ganglion cell input or the inhibition of gap junctional coupling abolished the rhythmic pattern. In rd10 and rd1 retinas the presynaptic network leads to local field potentials, whereas in bleached retinas additional pharmacological disinhibition is required to achieve detectable field potentials. Our results demonstrate that photoreceptor bleaching unmasks oscillatory activity in healthy retinas which shares many features with the functional phenotype detected in rd10 retinas. The quantitative physiological differences advance the understanding of the degeneration process and may guide future rescue strategies.

  2. Adsorption studies on bleaching of palm-kernel oil with activated ...

    Adsorption studies were performed on bleaching of palm-kernel oil (PKO) with different weight ratios of activated bentonite clay/PKO, ranging from 0.25% to 3% and at different temperatures of 70ºC, 80ºC, 90ºC and 100ºC. The equilibrium data generated were subsequently fitted with Langmuir and Freundlich adsorption ...

  3. Peroxy bleaches

    Carson, P.A.; Fairclough, C.S.; Mauduit, C.; Colsell, M.

    2006-01-01

    The thermodynamic and kinetic properties of a series of inorganic and organic peroxy bleaches were determined using adiabatic rate calorimetry and isothermal microcalorimetry. Results are compared to calculated oxygen balance values. The decomposition of the majority of the compounds is complex. Data indicate the need for cooling during the storage and transport for some materials evaluated. Although no overall structure/activity relationship could be established because of the diversity of molecular architectures studied, a combination of decomposition and activation energy data provides a means for hazard and risk classification

  4. Exogenous bleaching evaluation on dentin using chemical activated technique compared with diode laser technique

    Carvalho, Breno Carnevalli Franco de

    2003-01-01

    This in vitro study compared the results of different exogenous bleaching proceedings on dentin after treatment of enamel surface. Thirty human canine were hewn preserving the vestibular half of the crown and 3 mm of root, showing a vestibular-lingual thickness average of 3,5 mm, measuring in the third middle of the crown. Ali teeth were maintained in wet chamber during the experiment. Digital photographs were taken of the dentin surface at 3 experimental times (LI: initial record, L0: immediate pos-bleaching record and L 15: 15 days after bleaching). The teeth were divided into 3 experimental groups of 10 teeth in each. The Control Group did not receive any kind of treatment. The Laser Group received 2 session of laser bleaching, with 3 applications each, using 35% hydrogen peroxide, activated by diode laser during 30 seconds, by scanning the enamel surface from incisal edge to the top of the crown, from mesial to distal portion of the crown and circularly, each movement during 10 seconds. The following parameters being adopted: wavelength of 808 nm, power of 1,5 W and optic fiber with 600 μm (core). The Peroxide Group received 28 daily applications, during 4 hours each application, using 16% carbamide peroxide. The bleaching records were analysed using a computer, through RGBK (red, green , blue and black). The K averages (K=100% for black and K=0% for white) of the records for Control Group were: LI=50,1 %, L0=50,3% and L 15=50,6%. For Laser Group the K averages were LI=48,5%, L0=50,0% and L 15=47,7%. And for the Peroxide Group were LI=50,5%, L0=35,9% and L 15=37,3%. The statistical analysis showed no significant difference of the K between the Control Group and the Laser Group, as to LI, L0 and L 15. Only Peroxide Group showed significant statistical difference between LI with L0 and L 15 (0,1%), and L0 in comparison with L 15 did not show any difference. (author)

  5. Activation/waste management

    Maninger, C.

    1984-10-01

    The selection of materials and the design of the blankets for fusion reactors have significant effects upon the radioactivity generated by neutron activation in the materials. This section considers some aspects of materials selection with respect to waste management. The activation of the materials is key to remote handling requirements for waste, to processing and disposal methods for waste, and to accident severity in waste management operations. In order to realize the desirable evnironmental potentials of fusion power systems, there are at least three major goals for waste management. These are: (a) near-surface burial; (b) disposal on-site of the fusion reactor; (c) acceptable radiation doses at least cost during and after waste management operations

  6. Thermal and optical bleaching of radiation effects in silver activated metaphosphate glass - its use in U.V. dosimetry

    Nagpal, J.S.; Ramanathan, G.; Gangadharan, P.

    1976-01-01

    While investigating the use of silver activated metaphosphate glass in radiation dosimetry, using its properties of radiophotoluminescence (RPL) in the range 20 mR to 10 3 R and of optical absorbance changes at higher exposures, a difference in the behaviour of the centers responsible for the two phenomenon was observed when the glass was exposed to 253.7 nm u.v. Ultraviolet exposure was observed to bleach the radiophotoluminescence in an irradiated glass whereas it was observed to induce photoluminescence in an unirradiated glass. Thermal behaviour of the two centers was also different. After heating the glass for 5 min at a number of temperatures, a gradual increase in RPL was observed up to 200 0 C. Above 200 0 C, the thermal treatment bleached the RPL. The optical absorbance was bleached from room temperature upwards. (U.K.)

  7. Peroxy bleaches

    Carson, P.A. [Unilever Research, Port Sunlight Laboratory (United States) and Chemistry Department, University of Manchester, Institute of Science and Technology (United States)]. E-mail: pcarson2005@aol.com; Fairclough, C.S. [Unilever Research, Port Sunlight Laboratory (United States); Mauduit, C. [Chemistry Department, University of Manchester, Institute of Science and Technology (United States); Colsell, M. [Chemistry Department, University of Manchester, Institute of Science and Technology (United States)

    2006-08-25

    Fabric laundering is now a sophisticated chemical process involving a variety of operations including bleaching. The chemistry of peroxy bleaches is described including the use of novel organic compounds to provide effective bleaching at the lower temperatures of modern wash cycles. The instability of peroxy compounds is illustrated using cameo case histories to relate theory and practice. Techniques available for determining their thermochemistry are summarised. A model is provided for hazard and risk assessment of development projects in general (particularly those involving new molecules, processes or formulations) from ideas phase through exploratory laboratory investigations to pilot plant scale-up and eventual manufacture and commercial exploitation. This paper is a prelude to Part 2, which describes the determination of thermodynamic and kinetic properties of peroxy bleaches and discusses the implication of the results in terms of precautions for their safe storage and incorporation into detergent formulations during processing.

  8. Peroxy bleaches

    Carson, P.A.; Fairclough, C.S.; Mauduit, C.; Colsell, M.

    2006-01-01

    Fabric laundering is now a sophisticated chemical process involving a variety of operations including bleaching. The chemistry of peroxy bleaches is described including the use of novel organic compounds to provide effective bleaching at the lower temperatures of modern wash cycles. The instability of peroxy compounds is illustrated using cameo case histories to relate theory and practice. Techniques available for determining their thermochemistry are summarised. A model is provided for hazard and risk assessment of development projects in general (particularly those involving new molecules, processes or formulations) from ideas phase through exploratory laboratory investigations to pilot plant scale-up and eventual manufacture and commercial exploitation. This paper is a prelude to Part 2, which describes the determination of thermodynamic and kinetic properties of peroxy bleaches and discusses the implication of the results in terms of precautions for their safe storage and incorporation into detergent formulations during processing

  9. CRNL active waste incinerator

    McQuade, D.W.

    1965-02-01

    At CRNL the daily collection of 1200 pounds of active combustible waste is burned in a refractory lined multi-chamber incinerator. Capacity is 500-550 pounds per hour; volume reduction 96%. Combustion gases are cooled by air dilution and decontaminated by filtration through glass bags in a baghouse dust collector. This report includes a description of the incinerator plant, its operation, construction and operating costs, and recommendations for future designs. (author)

  10. Differential coral bleaching-Contrasting the activity and response of enzymatic antioxidants in symbiotic partners under thermal stress.

    Krueger, Thomas; Hawkins, Thomas D; Becker, Susanne; Pontasch, Stefanie; Dove, Sophie; Hoegh-Guldberg, Ove; Leggat, William; Fisher, Paul L; Davy, Simon K

    2015-12-01

    Mass coral bleaching due to thermal stress represents a major threat to the integrity and functioning of coral reefs. Thermal thresholds vary, however, between corals, partly as a result of the specific type of endosymbiotic dinoflagellate (Symbiodinium sp.) they harbour. The production of reactive oxygen species (ROS) in corals under thermal and light stress has been recognised as one mechanism that can lead to cellular damage and the loss of their symbiont population (Oxidative Theory of Coral Bleaching). Here, we compared the response of symbiont and host enzymatic antioxidants in the coral species Acropora millepora and Montipora digitata at 28°C and 33°C. A. millepora at 33°C showed a decrease in photochemical efficiency of photosystem II (PSII) and increase in maximum midday excitation pressure on PSII, with subsequent bleaching (declining photosynthetic pigment and symbiont density). M. digitata exhibited no bleaching response and photochemical changes in its symbionts were minor. The symbiont antioxidant enzymes superoxide dismutase, ascorbate peroxidase, and catalase peroxidase showed no significant upregulation to elevated temperatures in either coral, while only catalase was significantly elevated in both coral hosts at 33°C. Increased host catalase activity in the susceptible coral after 5days at 33°C was independent of antioxidant responses in the symbiont and preceded significant declines in PSII photochemical efficiencies. This finding suggests a potential decoupling of host redox mechanisms from symbiont photophysiology and raises questions about the importance of symbiont-derived ROS in initiating coral bleaching. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Low-Activity Radioactive Wastes

    In 2003 EPA published an Advance Notice of Proposed Rulemaking (ANPR) to collect public comment on alternatives for disposal of waste containing low concentrations of radioactive material ('low-activity' waste).

  12. Improved pulp bleaching potential of Bacillus subtilis WB800 through overexpression of three lignolytic enzymes from various bacteria.

    Ozer, Aysegul; Uzuner, Ugur; Guler, Halil Ibrahim; Ay Sal, Fulya; Belduz, Ali Osman; Deniz, Ilhan; Canakci, Sabriye

    2017-12-29

    A chemical bleaching process of paper pulps gives off excessive amount of chlorinated organic wastes mostly released to environment without exposing complete bioremediaton. Recent alternative and eco-friendly approaches toward pulp bleaching appear more responsive to environmental awareness. Here we report, direct use of a recombinant Bacillus subtilis bacterium for pulp bleaching, endowed with three ligninolytic enzymes from various bacteria. In addition, efficient bleaching performance from glutathione-S-transferase (GST) biocatalyst tested for the first time in pulp bleaching applications was also achieved. Simultaneous and extracellular overproduction of highly active GST, laccase, and lignin peroxidase catalysts were also performed by Bacillus cells. Both enhanced bleaching success and improved delignification rates were identified when enzyme combinations tested on both pine kraft and waste paper pulps, ranging from 69.75% to 79.18% and 60.89% to 74.65%, respectively. Furthermore, when triple enzyme combination applied onto the papers from pine kraft and waste pulps, the best ISO brightness values were identified as 66.45% and 64.67%, respectively. The delignification rates of pulp fibers exposed to various enzymatic bleaching sequences were comparatively examined under SEM. In conclusion, the current study points out that in near future, a more fined-tuned engineering of pulp-colonizing bacteria may become a cost-effective and environmentally friendly alternative to chemical bleaching. © 2017 International Union of Biochemistry and Molecular Biology, Inc.

  13. High activity waste disposal

    Gaul, W.C.

    1990-01-01

    Chem-Nuclear Environmental Services (CNES) has developed a container that is capable of containing high activity waste and can be shipped as a regular DOT Type A shipment. By making the container special form the amount of activity that can be transported in a Type A shipment is greatly enhanced. Special form material presents an extra degree of protection to the environment by requiring the package to be destroyed to get access to the radioactive material and must undergo specific testing requirements, whereas normal form material can allow access to the radioactive material. With the special form container up to 10 caries of radium can be transported in a single package. This paper will describe the considerations that were taken to develop these products

  14. Waste treatment activities incineration

    Weber, D.A.

    1985-01-01

    The waste management policy at SRP is to minimize waste generation as much as possible and detoxify and/or volume reduce waste materials prior to disposal. Incineration is a process being proposed for detoxification and volume reduction of combustion nonradioactive hazardous, low-level mixed and low-level beta-gamma waste. Present operation of the Solvent Burner Demonstration reduces the amount of solid combustible low-level beta-gamma boxed waste disposed of by shallow land burial by approximately 99,000 ft 3 per year producing 1000 ft 3 per year of ash and, by 1988, will detoxify and volume reduce 150,000 gallons or organic Purex solvent producing approximately 250 ft 3 of ash per year

  15. Zinc-Containing Hydroxyapatite Enhances Cold-Light-Activated Tooth Bleaching Treatment In Vitro

    Yi Li

    2017-01-01

    Full Text Available Cold-light bleaching treatment has grown to be a popular tooth whitening procedure in recent years, but its side effect of dental enamel demineralization is a widespread problem. The aim of this study was to synthesize zinc-substituted hydroxyapatite as an effective biomaterial to inhibit demineralization or increase remineralization. We synthesized zinc-substituted hydroxyapatite containing different zinc concentrations and analysed the product using X-ray diffraction (XRD, Fourier transform infrared (FTIR spectroscopy, and energy dispersive spectrometer (EDS. The biological assessment of Zn-HA was conducted by CCK-8 assay and bacterial inhibition tests. pH cycling was performed to estimate the effect of Zn-HA on the enamel surface after cold-light bleaching treatment. The XRD, FTIR, and EDS results illustrated that zinc ions and hydroxyapatite combined in two forms: (1 Zn2+ absorbed on the surface of HA crystal and (2 Zn2+ incorporated into the lattice of HA. The results indicated that 2% Zn-HA, 4% Zn-HA, and 8% Zn-HA effectively inhibited the growth of bacteria yet showed poor biocompatibility, whereas 1% Zn-HA positively affected osteoblast proliferation. The XRD and scanning electron microscopy (SEM results showed that the use of Zn-HA in pH cycling is obviously beneficial for enamel remineralization. Zinc-substituted hydroxyapatite could be a promising biomaterial for use in cold-light bleaching to prevent enamel demineralization.

  16. Zinc-Containing Hydroxyapatite Enhances Cold-Light-Activated Tooth Bleaching Treatment In Vitro

    Shi, Xinchang

    2017-01-01

    Cold-light bleaching treatment has grown to be a popular tooth whitening procedure in recent years, but its side effect of dental enamel demineralization is a widespread problem. The aim of this study was to synthesize zinc-substituted hydroxyapatite as an effective biomaterial to inhibit demineralization or increase remineralization. We synthesized zinc-substituted hydroxyapatite containing different zinc concentrations and analysed the product using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and energy dispersive spectrometer (EDS). The biological assessment of Zn-HA was conducted by CCK-8 assay and bacterial inhibition tests. pH cycling was performed to estimate the effect of Zn-HA on the enamel surface after cold-light bleaching treatment. The XRD, FTIR, and EDS results illustrated that zinc ions and hydroxyapatite combined in two forms: (1) Zn2+ absorbed on the surface of HA crystal and (2) Zn2+ incorporated into the lattice of HA. The results indicated that 2% Zn-HA, 4% Zn-HA, and 8% Zn-HA effectively inhibited the growth of bacteria yet showed poor biocompatibility, whereas 1% Zn-HA positively affected osteoblast proliferation. The XRD and scanning electron microscopy (SEM) results showed that the use of Zn-HA in pH cycling is obviously beneficial for enamel remineralization. Zinc-substituted hydroxyapatite could be a promising biomaterial for use in cold-light bleaching to prevent enamel demineralization. PMID:29159178

  17. Response surface modeling of acid activation of raw diatomite using in sunflower oil bleaching by: Box-Behnken experimental design.

    Larouci, M; Safa, M; Meddah, B; Aoues, A; Sonnet, P

    2015-03-01

    The optimum conditions for acid activation of diatomite for maximizing bleaching efficiency of the diatomite in sun flower oil treatment were studied. Box-Behnken experimental design combining with response surface modeling (RSM) and quadratic programming (QP) was employed to obtain the optimum conditions of three independent variables (acid concentration, activation time and solid to liquid) for acid activation of diatomite. The significance of independent variables and their interactions were tested by means of the analysis of variance (ANOVA) with 95 % confidence limits (α = 0.05). The optimum values of the selected variables were obtained by solving the quadratic regression model, as well as by analyzing the response surface contour plots. The experimental conditions at this global point were determined to be acid concentration = 8.963 N, activation time = 11.9878 h, and solid to liquid ratio = 221.2113 g/l, the corresponding bleaching efficiency was found to be about 99 %.

  18. Solidification of highly active wastes

    Morris, J.B.

    1986-07-01

    This document contains the annual reports for the contracts: (A) Glass Technology; (B) Calcination of Highly Active Waste Liquors; (C) Formation and Trapping of Volatile Ruthenium; (D) Deposition of Ruthenium; (E) Enhancement of Off-Gas Aerosol Collection; (F) Volatilisation of Cs, Tc and Te in High Level Waste Vitrification. (author)

  19. Treatment of solid non-active wastes

    Chmielewska, E.

    2008-01-01

    In this part of the text-book treatment of solid non-active wastes is described. This part consist of following chapters: (1) Law on wastes; (2) Present situation in waste management; (3) Strategic tendencies of waste management; (4) Incineration (disposal of solid wastes); (5) Disposal; (6) Composting; (7) Treatment of sludge from sewage clarification plant; (8) Biodegradation; (9) Recycling of wastes (assessing of secondary raw materials). Legal aspects of treatment of solid non-active wastes is presented

  20. Kraft pulp bleaching with molybdenum activated acid peroxide (P{sub Mo} stage); Branqueamento de polpa celulosica kraft de eucalipto com peroxido acido ativado por molibdenio

    Rabelo, Marcos Sousa [Servico Nacional de Aprendizagem Industrial (SENAI), Lauro de Freitas, BA (Brazil). Dept. Regional da Bahia; Silva, Vanessa Lopes; Barros, Denise Pires de; Colodette, Jorge Luiz [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Florestal; Sacon, Vera Maria; Silva, Marcelo Rodrigues da [Votorantim Celulose e Papel, Jacarei, SP (Brazil)

    2009-07-01

    Optimum conditions to run the P{sub Mo} stage for bleaching eucalyptus kraft pulp were 90 deg C, pH 3.5, 2 h, 0.1 kg/t Mo and 5 kg/t H{sub 2}O{sub 2}. The P{sub Mo} stage efficiency increased with decreasing pH (1.5-5.5) and increasing temperature (75-90 deg C), time (2-4 h), and hydrogen peroxide (3-10 kg/t) and molybdenum concentration (0.1-0.4 kg/t). The implementation of the P{sub Mo} stage, as replacement for the A stage, decreased total active chlorine demand of the OAZDP sequence by 6 kg/t to reach 90% ISO, both in laboratory and mill scale. Such practice resulted in decreased bleaching chemical costs to produce fully bleached pulp of 90% ISO. (author)

  1. Microtensile bond strength of enamel after bleaching.

    Lago, Andrea Dias Neves; Garone-Netto, Narciso

    2013-01-01

    To evaluate the bond strength of a composite resin to the bovine enamel bleached with 35% hydrogen peroxide. It was used an etching-and-rinse adhesive system employed immediately, 7 and 14 days after the bleaching. Twenty bovine teeth were randomly distributed into 4 groups (n = 5), 3 experimental and 1 control. G1: Unbleached + restoration 14 days after storage in artificial saliva (control); G2: Bleached + restoration immediately after bleaching; G3: Bleached + restoration 7 days after bleaching; G4: Bleached + restoration 14 days after bleaching. Their buccal enamel surfaces were flattened, and a 25 mm² (5 × 5 mm) area from each one of these regions was outlined so as to standardize the experimental region. Universal hybrid composite resin Filtek™Z350 was inserted into four layers of 1 mm each and photo-activated. The bond strength was quantitatively evaluated by a microtensile test (1.0 mm/min) 24 h after the restorative procedures. The failure mode was assessed through scanning electron microscopy (SEM). There was a significant reduction in the bond strength of the restored teeth immediately after the bleaching (G2). There were no significant differences in enamel bond strength between groups G1, G3, and G4. There was a predominance of adhesive and mixed (cohesive + adhesive) failure in all groups. The 7-day-period after the end of the bleaching with 35% hydrogen peroxide was enough to achieve the appropriate values of bond strength to the enamel.

  2. Radiation coloration and bleaching of glass

    Treadaway, M.J.; Passenheim, B.C.; Kitterer, B.D.; Schall, P.

    1976-01-01

    The results of an investigation of the bleaching of radiation-induced darkening in ten Schott optical glasses is presented. Measurements were made at several temperatures from 160K to 340K for times from 5 msec to 500 hours after exposure. The theory of processes distributed in activation energies has been used to formulate a model which explains the time and temperature dependence of the bleaching. Analysis of the bleaching results in terms of this model has yielded the activation energy distributions and ''frequency factors'' which govern the bleaching for each material

  3. Color Recovery Effect of Different Bleaching Systems on a ...

    2017-12-05

    Dec 5, 2017 ... KEYWORDS: Composite resin, discoloration, home bleaching, laser activated bleaching, office ... hexametaphosphate, which protect the teeth surface from .... exposure, saliva and other fluids diluting the staining .... Penetration of the pulp ... dentin permeability of carbamide peroxide and hydrogen peroxide.

  4. SECONDARY WASTE MANAGEMENT STRATEGY FOR EARLY LOW ACTIVITY WASTE TREATMENT

    TW, CRAWFORD

    2008-07-17

    This study evaluates parameters relevant to River Protection Project secondary waste streams generated during Early Low Activity Waste operations and recommends a strategy for secondary waste management that considers groundwater impact, cost, and programmatic risk. The recommended strategy for managing River Protection Project secondary waste is focused on improvements in the Effiuent Treatment Facility. Baseline plans to build a Solidification Treatment Unit adjacent to Effluent Treatment Facility should be enhanced to improve solid waste performance and mitigate corrosion of tanks and piping supporting the Effiuent Treatment Facility evaporator. This approach provides a life-cycle benefit to solid waste performance and reduction of groundwater contaminants.

  5. Color Recovery Effect of Different Bleaching Systems on a ...

    Composite samples were immersed in coffee and turnip juice for 1 week in each. One laser activated bleaching (LB) (Biolase Laserwhite*20) and three conventional bleaching systems (Ultradent Opalescence Boost 40% (OB), Ultradent Opalescence PF 15% home bleaching (HB), Crest 3D White [Whitening Mouthwash]) ...

  6. Reef corals bleach to resist stress.

    Obura, David O

    2009-02-01

    A rationale is presented here for a primary role of bleaching in regulation of the coral-zooxanthellae symbiosis under conditions of stress. Corals and zooxanthellae have fundamentally different metabolic rates, requiring active homeostasis to limit zooxanthellae production and manage translocated products to maintain the symbiosis. The control processes for homeostasis are compromised by environmental stress, resulting in metabolic imbalance between the symbionts. For the coral-zooxanthella symbiosis the most direct way to minimize metabolic imbalance under stress is to reduce photosynthetic production by zooxanthellae. Two mechanisms have been demonstrated that do this: reduction of the chlorophyll concentration in individual zooxanthellae and reduction of the relative biomass of zooxanthellae. Both mechanisms result in visual whitening of the coral, termed bleaching. Arguments are presented here that bleaching provides the final control to minimize physiological damage from stress as an adversity response to metabolic imbalance. As such, bleaching meets the requirements of a stress response syndrome/general adaptive mechanism that is sensitive to internal states rather than external parameters. Variation in bleaching responses among holobionts reflects genotypic and phenotypic differentiation, allowing evolutionary change by natural selection. Thus, reef corals bleach to resist stress, and thereby have some capacity to adapt to and survive change. The extreme thermal anomalies causing mass coral bleaching worldwide lie outside the reaction norms for most coral-zooxanthellae holobionts, revealing the limitations of bleaching as a control mechanism.

  7. Solid Waste Activity Packet for Teachers.

    Illinois Univ., Urbana. Cooperative Extension Service.

    This solid waste activity packet introduces students to the solid waste problem in Illinois. Topics explore consumer practices in the market place, packaging, individual and community garbage generation, and disposal practices. The activities provide an integrated approach to incorporating solid waste management issues into subject areas. The…

  8. Microtensile bond strength of enamel after bleaching

    Andréa Dias Neves Lago

    2013-01-01

    Full Text Available Objective: To evaluate the bond strength of a composite resin to the bovine enamel bleached with 35% hydrogen peroxide. It was used an etching-and-rinse adhesive system employed immediately, 7 and 14 days after the bleaching. Materials and Methods: Twenty bovine teeth were randomly distributed into 4 groups (n = 5, 3 experimental and 1 control. G1: Unbleached + restoration 14 days after storage in artificial saliva (control; G2: Bleached + restoration immediately after bleaching; G3: Bleached + restoration 7 days after bleaching; G4: Bleached + restoration 14 days after bleaching. Their buccal enamel surfaces were flattened, and a 25 mm² (5 × 5 mm area from each one of these regions was outlined so as to standardize the experimental region. Universal hybrid composite resin Filtek™Z350 was inserted into four layers of 1 mm each and photo-activated. The bond strength was quantitatively evaluated by a microtensile test (1.0 mm/min 24 h after the restorative procedures. The failure mode was assessed through scanning electron microscopy (SEM. Results: There was a significant reduction in the bond strength of the restored teeth immediately after the bleaching (G2. There were no significant differences in enamel bond strength between groups G1, G3, and G4. There was a predominance of adhesive and mixed (cohesive + adhesive failure in all groups. Conclusion: The 7-day-period after the end of the bleaching with 35% hydrogen peroxide was enough to achieve the appropriate values of bond strength to the enamel.

  9. Bleaching Dengan Teknologi Laser

    Eliwaty

    2008-01-01

    Penulisan tentang bleaching dengan laser dimaksudkan untuk menambah wawasan serta pengetahuan dari pembaca di bidang kedokteran gigi. Macam-macam laser yang dipergunakan dalam bleaching yaitu argon, CO2 serta dioda laser. Contoh merek produk laser yaitu Blulaze, Dentcure untuk argonlaser, Novapulse untuk C02 serta Opus 5 untuk dioda laser. Laser bleaching hasilnya dapat dicapai dalam satu kunjungan saja, cepat, efisien namun biayanya relatif mahal, dapat menimbulkan burn, sensitivitas se...

  10. Effects of black liquor shocks on activated sludge treatment of bleached kraft pulp mill wastewater.

    Morales, Gabriela; Pesante, Silvana; Vidal, Gladys

    2015-01-01

    Kraft pulp mills use activated sludge systems to remove organic matter from effluents. Process streams may appear as toxic spills in treatment plant effluents, such as black liquor, which is toxic to microorganisms of the activated sludge. The present study evaluates the effects of black liquor shocks in activated sludge systems. Four black liquor shocks from 883 to 3,225 mg chemical oxygen demand-COD L(-1) were applied during 24 hours in a continuously operating lab-scale activated sludge system. Removal efficiencies of COD, color and specific compounds were determined. Moreover, specific oxygen uptake rate (SOUR), sludge volumetric index (SVI) and indicator microorganisms were evaluated. Results show that the addition of black liquor caused an increase in COD removal (76-67%) immediately post shock; followed two days later by a decrease (-19-50%). On the other hand, SOUR ranged between 0.152 and 0.336 mgO2 g(-1) volatile suspended solids-VSS• min(-1) during shocks, but the initial value was reestablished at hour 24. When the COD concentration of the shock was higher than 1,014 mg/L, the abundance of stalked ciliates and rotifers dropped. Finally, no changes in SVI were observed, with values remaining in the range 65.8-40.2 mL g(-1) total suspended solids-TSS during the entire operating process. Based on the results, the principal conclusion is that the activated sludge system with the biomass adapted to the kraft pulp effluent could resist a black liquor shock with 3,225 mgCOD L(-1) of concentration during 24 h, under this study's conditions.

  11. Opalescence of bleached teeth.

    Schmeling, Max; Maia, Hamilton Pires; Baratieri, Luiz Narciso

    2012-07-01

    To evaluate the influence of tooth bleaching on the opalescence properties of enamel. Color of 38 specimens was determined by colorimetric analysis before and after bleaching in the reflectance and transmittance modes. The results were described as CIELab color coordinates. The Opalescent Parameter (OP) was calculated as the difference in yellow-blue color coordinate (CIE Δb*) and red-green color coordinate (CIE Δa*) between the reflected and transmitted colors. Mean OP value of the specimens was 18.9 (±1.6) before bleaching and 16.1 (±1.0) after bleaching. Bleaching decreases the OP of the specimens (p>0.001). OP decrease was correlated with differences in b* color coordinate in the transmittance mode. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Solidification of highly active wastes

    Morris, J.B.

    1984-11-01

    Final reports are presented on work on the following topics: glass technology; enhancement of off-gas aerosol collection; formation and trapping of volatile ruthenium; volatilisation of caesium, technetium and tellurium in high-level waste vitrification; deposition of ruthenium; and calcination of high-level waste liquors. (author)

  13. Recent activity on disposal of uranium waste

    Fujiwara, Noboru

    1999-01-01

    The concept on the disposal of uranium waste has not been discussed in the Atomic Energy Commission of Japan, but the research and development of it are carried out in the company and agency which are related to uranium waste. In this paper, the present condition and problems on disposal of uranium waste were shown in aspect of the nuclear fuel manufacturing companies' activity. As main contents, the past circumstances on the disposal of uranium waste, the past activity of nuclear fuel manufacturing companies, outline and properties of uranium waste were shown, and ideas of nuclear fuel manufacturing companies on the disposal of uranium waste were reported with disposal idea in the long-term program for development and utilization of nuclear energy. (author)

  14. Disposal of high-activity nuclear wastes

    Hamilton, E.I.

    1983-01-01

    A discussion is presented on the deep sea ocean disposal for high-activity nuclear wastes. The following topics are covered: effect of ionizing radiation on marine ecosystems; pathways by which radionuclides are transferred to man from the marine environment; information about releases of radioactivity to the sea; radiological protection; storage and disposal of radioactive wastes and information needs. (U.K.)

  15. Nuclear waste isolation activities report

    1980-12-01

    Included are: a report from the Deputy Assistant Secretary, a summary of recent events, new literature, a list of upcoming waste management meetings, and background information on DOE's radwaste management programs

  16. Bleach vs. Bacteria

    ... Articles | Inside Life Science Home Page Bleach vs. Bacteria By Sharon Reynolds Posted April 2, 2014 Your ... hypochlorous acid to help kill invading microbes, including bacteria. Researchers funded by the National Institutes of Health ...

  17. The combination of activated natural zeolite-bentonite to reduce Fe and Cu in refined bleached palm oil (RBPO) by using atomic absorption spectrophotometer method

    Zakwan; Raja, PM; Giyanto

    2018-02-01

    Indonesia is one of the crude palm oil (CPO) production country in the world. As many products are derivated from the CPO, the quality must be increased continuously. One of the things that influence the quality of palm oil is the Fe and Cu content. The objective of this research was to reduce Fe and Cu content in Refined Bleached Palm Oil (RBPO). In processing CPO or Refined Bleachead Palm Oil (RBPO) may be contaminated by Fe and Cu from metal tank and pipe in the factory. The zeolite and bentonite was activated by maceration method using hydrochloric acid (0,1 N). Four batch reactions consisting of refined palm oil (RPO), activated natural zeolite-bentonite (ANZB) was bleached by heating and stirring them at about 105°C and 1200 rpm for 30 minutes. The results showed that all combinations of ANZB can reduce the Fe content. Thereafter, the optimal combination of ANZB was obtained in K1, K2 and K4 with Cu content 0.02 ppm. In the future, it is needed to study on the reduction of the Fe and Cu content in palm oil with the other adsorbent.

  18. Status of defense radioactive waste disposal activities

    Wade, T.W.

    1988-01-01

    The Office of Defense Programs, U.S. Department of Energy, is responsible for the production of nuclear weapons and materials for national defense. As a byproduct to their activities, nuclear production facilities have generated, and will continue to generate, certain radioactive, hazardous, or mixed wastes that must be managed and disposed of in a safe and cost-effective manner. Compliance with all applicable Federal and State regulations is required. This paper describes the principal elements that comprise Defense Programs' approach to waste management and disposal. The status of high-level, transuranic, and low-level radioactive waste disposal is set forth. Defense Programs' activities in connection with the environmental restoration of inactive facilities and with the safe transport of waste materials are summarized. Finally, the principal challenges to realizing the goals set for the defense waste program are discussed in terms of regulatory, public acceptance, technical, and budget issues

  19. Therapeutic effectiveness of a new enzymatic bleaching dentifrice.

    Forner, Leopaldo; Amengual, José; Liena, Carmen; Riutord, Pere

    2012-01-01

    Research into bleaching focuses on new products in order to minimize undesirable effects. This study evaluated the bleaching effectiveness of a new enzymatic-activated dentifrice. A total of 20 volunteers were bleached with a dentifrice containing 5% lactoperoxidase and 3% carbamide peroxide applied three times a day for two minutes over 21 days. Color was recorded before and after the treatment using a spectrophotometer. CIELAB differences were calculated before and after treatment using the paired t test (P whitening teeth. Enzymatic dental bleaching is able to increase the efficiency of low concentration peroxides, reducing the potential risk of peroxides on oral tissues.

  20. Bacteriological studies on dairy waste activated sludge

    Adamse, A.D.

    1966-01-01

    Dairy-waste activated sludge was examined for bacterial composition and response to different conditions. Strains isolated were classified mainly into three groups: predominantly coryneform bacteria (largely Arthrobacter), some Achromobacteraceae and a small groups of Pseudomonadaceae.

  1. Recovery of Spent Bleaching Earth From Palm Oil Refining Using Radiation

    Nor Azillah Fatimah Othman; Tuan Amran Tuan Abdullah; Nor Azillah Fatimah Othman; Nor Azwin Shukri; Selambakkanu, S.; Siti Fatahiyah Mohamad

    2014-01-01

    Acid activated calcium montmorillonite clay or commonly referred to as bleaching clays is one type of clay used in physical refining of palm oil and it is prioritized in removing a variety of undesirable impurities which would otherwise impart colour, odour and taste to the refined product. Used-up bleaching clays or known as Spent Bleaching Earth (SBE) is considered as industrial waste and commonly dispose without any pretreatment. SBE usually contains considerable quantities of entrained oil that is quantified approximately to 30 to 40 %. The residual oil in these principal solid waste products can rapidly oxidize to the point of spontaneous ignition as a result of clay-catalyzed auto-oxidation reactions. Due to this fact, the disposal of SBE has become an environmental problem and pretreatment of SBE is very important. There are several studies on the residual oil removal from the SBE using heat treatment. Radiation generated from electron beam accelerator can supply high energy to break the C-C and C-H bond. It is expected that the removal of hydrocarbon will occurs at high rate compared to conventional heating. This research proposes the use of radiation on the recovery of SBE from palm oil refining waste. Evaluation of radiation effect on properties of SBE will be conducted to study the effectiveness of using radiation in the purification process. Finally, the material produced will be evaluated and characterized for regeneration and reuse purpose. (author)

  2. Patterns of coral bleaching: Modeling the adaptive bleaching hypothesis

    Ware, J.R.; Fautin, D.G.; Buddemeier, R.W.

    1996-01-01

    Bleaching - the loss of symbiotic dinoflagellates (zooxanthellae) from animals normally possessing them - can be induced by a variety of stresses, of which temperature has received the most attention. Bleaching is generally considered detrimental, but Buddemeier and Fautin have proposed that bleaching is also adaptive, providing an opportunity for recombining hosts with alternative algal types to form symbioses that might be better adapted to altered circumstances. Our mathematical model of this "adaptive bleaching hypothesis" provides insight into how animal-algae symbioses might react under various circumstances. It emulates many aspects of the coral bleaching phenomenon including: corals bleaching in response to a temperature only slightly greater than their average local maximum temperature; background bleaching; bleaching events being followed by bleaching of lesser magnitude in the subsequent one to several years; higher thermal tolerance of corals subject to environmental variability compared with those living under more constant conditions; patchiness in bleaching; and bleaching at temperatures that had not previously resulted in bleaching. ?? 1996 Elsevier Science B.V. All rights reserved.

  3. Immune defenses of healthy, bleached and diseased Montastraea faveolata during a natural bleaching event.

    Mydlarz, Laura D; Couch, Courtney S; Weil, Ernesto; Smith, Garriet; Harvell, C Drew

    2009-11-16

    One prominent hypothesis regarding climate change and scleractinian corals is that thermal stress compromises immune competence. To test this hypothesis we tracked how the immune defenses of bleached, apparently healthy and yellow band disease (YBD) diseased Montastraea faveolata colonies varied with natural thermal stress in southwestern Puerto Rico. Colonies were monitored for 21 mo from the peak of the bleaching event in October 2005 to August 2007. Since sea surface temperature was significantly higher in summer and fall 2005 than 2006, year of collection was used as a proxy for temperature stress, and colony fragments collected in 2005 were compared with those collected in 2006. Mortality rate was high (43% overall) and all colonies (except one) either died or became infected with YBD by August 2007. YBD-infected tissue did not bleach (i.e. expel zooxanthellae) during the 2005 bleaching event, even when healthy tissue of these colonies bleached. Immune activity was assayed by measuring prophenoloxidase (PPO), peroxidase (POX), lysozyme-like (LYS) and antibacterial (AB) activity. Immune activity was variable between all coral samples, but there was a significant elevation of PPO activity in bleached colonies collected in 2005 relative to apparently healthy and YBD-diseased corals in 2006. In YBD-diseased colonies, LYS and AB activity were elevated in both healthy and infected tissue, indicating a systemic response; activity levels in these colonies were higher compared to those that appeared healthy. In both these immune parameters, there was a trend for suppression of activity in corals that were bleached in 2005. These data, while complicated by between-genet variability, illustrate the complex interaction between disease and temperature stress on immune function.

  4. Activity monitoring of alpha-bearing wastes

    Birkhoff, G.; Bondar, L.

    1980-01-01

    The paper aims at the survey on the actual situation in activity monitoring of alpha-bearing wastes. Homogeneous materials such as liquid-, gaseous- and homogeneous solid wastes are amenable to destructive analyses of representative samples. Available destructive analyses methods are sensitive and precise enough to cope with all requirements in alpha-waste monitoring. The more difficult problems are encountered with alpha-contaminated solids, when representative sampling is not practicable. Non-destructive analysis techniques are applied for monitoring this category of solid wastes. The techniques for nondestructive analysis of alpha-bearing wastes are based on the detection of gamma and/or neutron-emission of actinides. Principles and a theory of non-destructive radiometric assay of plutonium contaminated solid waste streams are explained. Guidelines for the calibration of instruments and interpretation of experimental data are given. Current theoretical and experimental development work in this problem area is reviewed. Evaluations concerning capabilities and limitations of monitoring systems for alpha-bearing solid wastes are very complex and out of the scope of this paper

  5. Technology development activities supporting tank waste remediation

    Bonner, W.F.; Beeman, G.H.

    1994-06-01

    This document summarizes work being conducted under the U.S. Department of Energy's Office of Technology Development (EM-50) in support of the Tank Waste Remediation System (TWRS) Program. The specific work activities are organized by the following categories: safety, characterization, retrieval, barriers, pretreatment, low-level waste, and high-level waste. In most cases, the activities presented here were identified as supporting tank remediation by EM-50 integrated program or integrated demonstration lead staff and the selections were further refined by contractor staff. Data sheets were prepared from DOE-HQ guidance to the field issued in September 1993. Activities were included if a significant portion of the work described provides technology potentially needed by TWRS; consequently, not all parts of each description necessarily support tank remediation

  6. Sludge disinfection by combined treatment of bleaching powder and irradiation

    Harsoyo

    1987-01-01

    Sludge disinfection by combined treatment of bleaching powder and irradiation. Disinfection of sludge by combined treatment of bleaching powder and irradiation has been investigated. Sludge were obtained from water and waste sanitation department (Dinas Kebersihan) DKI located at Kebon Nanas, Jakarta. Sludge were mixed with bleaching powder at the concentration of 0, 10 and 20 mg/l and then irradiated in multipurpose panoramic batch irradiator (PANBIT) with doses of 2, 4, 6, 8, and 10 kGy and a dose rate 9 kGy/h. The reducing colony form unit caused by the combined treatment depend on type bacteria observed in sludge. Pathogenic bacteria as Clostridium still survive at a dose of 10 kGy on sludge containing 20 mg/l bleaching powder, but Salmonella, Shigella, and Vibrio were not detected in this experiment, neither in the control nor in the irradiated samples. (author). 14 refs.; 4 figs

  7. Bleaching of Wool with Sodium Borohydride

    Duygu Yilmazer, MSc.; Mehmet Kanik, Ph.D.

    2009-01-01

    An untreated wool fabric was bleached both with sodium borohydride (SBH) in the presence of sodium bisulphite (SBS) solution and with a commercial H2O2 bleaching method. The concentration effects of SBH and SBS, bleaching time, pH and temperature on SBH bleaching process were investigated. Whiteness, yellowness and alkali solubility results were assessed for both bleaching methods. The results showed that whiteness degrees obtained with SBH bleaching was comparable with that of H2O2 bleaching...

  8. BLEACHING NEPTUNE BALLS

    BONET Maria Angeles

    2014-05-01

    Full Text Available Posidonia Oceanic is a seaweed from Mediterranean Sea and it is more concentrated at the Balerian SEA. This implies the Valencian Community also. It forms vaste underwater meadows in the sea and are part of the Mediterranean ecosystem. It is a sea-grass specie with fruits and flowers. Leaves are ribbon-like and they grow in winter and at the end of summer some of them are separated and arrive to some sea line. Fuit is separated and can floate, it is known as “the olive of the sea” mainly in Italy, or as the Neptune Balls. As it can be used in different fields, it is is being studied in order ro have the precitice tests. Some authors have reported the manufacturing of fully bio-based comites with a gluten matrix by hot-press molding. And it has been considered as an effective insulator for building industry or even though to determine the presence of mercure in the Mediterranean sea some years ago. As many applications can be designed from that fibers, it has been considered to be bleached in order to used them in fashionable products. Consequently, its original brown color is not the most suitable one and it should be bleached as many other cellulosic fibers. The aim of this paper is to bleache neptune balls however, the inner fibers were not accessible at all and it implied not to bleach the inner fibers in the neptune ball. Further studiesd will consider bleaching the individualized fibers.

  9. Effect of a New Bleaching Gel on Tooth Whitening.

    Barry, T N; Bailey, C W; Ashcraft-Olmscheid, D; Vandewalle, K S

    The purpose of this study was to compare the whitening efficacy of a novel bleaching agent containing a unique tribarrel hydremide-peroxide gel (KöR) with a traditional bleaching system of hydrogen peroxide or carbamide peroxide (Opalescence). Bovine incisors were mounted into a custom resin, arch-shaped mounting device. Four groups of 10 teeth were created using mounting devices containing five teeth each. The in-office and home bleaching gels of KöR and Opalescence were applied to the teeth alone and in trays to simulate a combination of in-office and home bleaching or home bleaching only. Spectrophotometer readings of L* a* b* were performed at baseline, the end of active bleaching (immediate), and three and six months postbleaching. Immediately postbleaching, the use of Opalescence gel resulted in greater change in ΔE* and Δb* (less yellow) for combined and home bleaching techniques compared with KöR. After six months, Opalescence had significantly greater ΔE* and Δb* compared with KöR for home bleaching only. There was no significant difference in ΔL* between Opalescence and KöR at any time period with either technique.

  10. Compaction and packaging of dry active municipal wastes

    Chen Zongming; Xi Xinmin

    1994-01-01

    The authors present the feature of a compaction system for active municipal wastes and the radiological monitoring results of workplace and environment. A variety of dry active municipal wastes could be compacted by this system. Volume reduction factor attained to 5 to 7 for soft wastes and 8 to 13 for hard wastes. No evident radiological impact was found on workplace and environment

  11. Nuclear waste: Status of DOE's nuclear waste site characterization activities

    1987-01-01

    Three potential nuclear waste repository sites have been selected to carry out characterization activities-the detailed geological testing to determine the suitability of each site as a repository. The sites are Hanford in south-central Washington State, Yucca Mountain in southern Nevada, and Deaf Smith in the Texas Panhandle. Two key issues affecting the total program are the estimations of the site characterization completion data and costs and DOE's relationship with the Nuclear Regulatory Commission which has been limited and its relations with affected states and Indian tribes which continue to be difficult

  12. Bleaching of the discolored traumatized tooth

    Dahl, Jon E.; Kopperud, Siemen E.; Pallesen, Ulla

    2018-01-01

    This chapter focuses on the treatment of discolored traumatized teeth, most of them being non-vital and subsequently, endodontically treated. Tooth bleaching based upon hydrogen peroxide as the active agent, applied directly or produced in a chemical reaction from sodium perborate or carbamide pe...

  13. The effect of two bleaching agents on the phosphate concentration of the enamel evaluated by Raman spectroscopy: An ex vivo study

    Sokkalingam Mothilal Venkatesan

    2012-01-01

    Full Text Available Aim : The aim of this ex vivo study was to evaluate the effect of in-office bleaching agents,-35% and 38% hydrogen peroxide containing bleaching agents, on the phosphate concentration of the enamel evaluated by Raman spectroscopy. Materials and Methods : Forty noncarious, craze-free human maxillary incisors, extracted for periodontal reasons, were used in this study. Baseline Raman spectra from each specimen were obtained before the application of the bleaching agent to assess the phosphate content present in the teeth. The teeth were divided into two groups: Group A - bleached with pola office bleach (35% hydrogen peroxide, potassium nitrate (light activated. Group B - bleached with opalescence Xtra bleach (38% hydrogen peroxide potassium nitrate and fluoride (chemical activated. After the bleaching procedure, the treated specimens were taken to obtain Raman spectra to assess the phosphate loss after bleaching treatment. Results : The results showed that the chemically activated bleaching agent showed less phosphate loss when compared with the light activated bleaching agent. Conclusion : Within the limitations of this study, it can be concluded that the chemically activated bleaching agent showed minimal phosphate loss when compared to light activated bleaching agent. The chemically activated bleaching agent was better than the light activated bleaching agent when values were evaluated statistically.

  14. Radioecological activity limits for radioactive waste disposal

    Ahmet, E. Osmanlioglu

    2006-01-01

    Full text: Near surface disposal is an option used by many countries for the disposal of radioactive waste containing mainly short lived radionuclides. Near surface disposal term includes broad range of facilities from simple trenches to concrete vaults. Principally, disposal of radioactive waste requires the implementation of measures that will provide safety for human health and environment now and in the future. For this reason preliminary activity limits should be determined to avoid radioecological problems. Radioactive waste has to be safely disposed in a regulated manner, consistent with internationally agreed principles and standards and with national legislations to avoid serious radioecological problems. The purpose of this study, presents a safety assessment approach to derive operational and post-closure radioecological activity limits for the disposal of radioactive waste. Disposal system has three components; the waste, the facility (incl. engineered barriers) and the site (natural barriers). Form of the waste (unconditioned or conditioned) is effective at the beginning of the migration scenerio. Existence of the engineered barriers in the facility will provide long term isolation of the waste from environment. The site characteristics (geology, groundwater, seismicity, climate etc.) are important for the safety of the system. Occupational exposure of a worker shall be controlled so that the following dose limits are not exceeded: an effective dose of 20mSv/y averaged over 5 consecutive years; and an effective dose of 50mSv in any single year. The effective dose limit for members of the public recommended by ICRP and IAEA is 1 mSv/y for exposures from all man-made sources [1,2]. Dose constraints are typically a fraction of the dose limit and ICRP recommendations (0.3 mSv/y) could be applied [3,4]. Radioecological activity concentration limits of each radionuclide in the waste (Bq/kg) were calculated. As a result of this study radioecological activity

  15. Enzyme Activities in Waste Water and Activated Sludge

    Nybroe, Ole; Jørgensen, Per Elberg; Henze, Mogens

    1992-01-01

    The purpose of the present study was to evaluate the potential of selected enzyme activity assays to determine microbial abundance and heterotrophic activity in waste water and activated sludge. In waste water, esterase and dehydrogenase activities were found to correlate with microbial abundance...... measured as colony forming units of heterotrophic bacteria. A panel of four enzyme activity assays, α-glucosidase, alanine-aminopeptidase, esterase and dehydrogenase were used to characterize activated sludge and anaerobic hydrolysis sludge from a pilot scale plant. The enzymatic activity profiles were...... distinctly different, suggesting that microbial populations were different, or had different physiological properties, in the two types of sludge. Enzyme activity profiles in activated sludge from four full-scale plants seemed to be highly influenced by the composition of the inlet. Addition of hydrolysed...

  16. Neutron Activation analysis of waste water

    Hernandez H, V.

    1997-01-01

    An instrumental neutron activation analysis for the simultaneous determination of chlorine, bromine, sodium, manganese, cobalt, copper, chromium, zinc, nickel, antimony and iron in waste water is described. They were determined in waste water samples under normal conditions by non-destructive neutron activation simultaneously using a suitable monostandard method. Standardized water samples were used and irradiated in polyethylene ampoules at a neutron flux of 10 13 cm -2 s -1 for periods of 1 minute, 1 and 10 hours. A Ge hyperpure detector was used for your activity determination, with count times of 60, 180, 300 and 600 seconds. The obtained results show than the method can be utilized for the determination of this elements without realize anything previous treatment of the samples. (Author)

  17. Gravitational sedimentation of flocculated waste activated sludge.

    Chu, C P; Lee, D J; Tay, J H

    2003-01-01

    The sedimentation characteristics of flocculated wastewater sludge have not been satisfactorily explored using the non-destructive techniques, partially owing to the rather low solid content (ca. 1-2%) commonly noted in the biological sediments. This paper investigated, for the first time, the spatial-temporal gravitational settling characteristics of original and polyelectrolyte flocculated waste activated sludge using Computerized Axial Tomography Scanner. The waste activated sludge possessed a distinct settling characteristic from the kaolin slurries. The waste activated sludges settled more slowly and reached a lower solid fraction in the final sediment than the latter. Flocculation markedly enhanced the settleability of both sludges. Although the maximum achievable solid contents for the kaolin slurries were reduced, flocculation had little effects on the activated sludge. The purely plastic rheological model by Buscall and White (J Chem Soc Faraday Trans 1(83) (1987) 873) interpreted the consolidating sediment data, while the purely elastic model by Tiller and Leu (J. Chin. Inst. Chem. Eng. 11 (1980) 61) described the final equilibrated sediment. Flocculation produced lower yield stress during transient settling, thereby resulting in the more easily consolidated sludge than the original sample. Meanwhile, the flocculated activated sludge was stiffer in the final sediment than in the original sample. The data reported herein are valuable to the theories development for clarifier design and operation.

  18. Underground disposal of high active waste

    Engelmann, H.J.

    1982-01-01

    This paper is concerned with the engineering aspects relating to the deep burial of high active waste in stable geological formations. The design of a repository depends upon a number of factors not least of which is the type of rock in which it is to be constructed. High level wastes must be isolated from man's environment for such periods that subsequent release will not result in an unacceptable hazard to human population. Design aspects of repositories are reviewed and conceptual design are present in relation to the geological formations under consideration. Over long time periods the most probable mode of release of radionuclides is through groundwater contacting the waste. The proposed concepts therefore include the use of engineered and natural barriers to delay the eventual release of waterborne radionuclides into mans environment. In all cases the ultimate barrier will be the geological formation. Nevertheless, depending upon the type of host rock, use will be made of various additional engineered barriers to delay water contacting the high level waste for several hundreds of years. During this time the level of radiation and associated heat emitted by the waste, will fall by several orders of magnitude and the rock temperatures within a repository will be returning to ambient. Thereafter the residual activity will mainly arise from the actinides. Containment may be enhanced by surrounding the canisters with materials having high sorption capabilities for many of the radionuclides involved. The depth at which a repository is excavated must be sufficient to ensure that the overburden will withstand changes in environmental conditions. The depth of cover required in different rock types may vary. In clay excavating at depth of up to -250 m appears feasible, while in hard rocks and salts working at depth of up to -1000 m is entirely practicable. (orig./RW)

  19. Hanford Tank Waste - Near Source Treatment of Low Activity Waste

    Ramsey, William Gene

    2013-01-01

    Abstract only. Treatment and disposition of Hanford Site waste as currently planned consists of 100+ waste retrievals, waste delivery through up to 8+ miles of dedicated, in-ground piping, centralized mixing and blending operations- all leading to pre-treatment combination and separation processes followed by vitrification at the Hanford Tank Waste Treatment and Immobilization Plant (WTP). The sequential nature of Tank Farm and WTP operations requires nominally 15-20 years of continuous operations before all waste can be retrieved from many Single Shell Tanks (SSTs). Also, the infrastructure necessary to mobilize and deliver the waste requires significant investment beyond that required for the WTP. Treating waste as closely as possible to individual tanks or groups- as allowed by the waste characteristics- is being investigated to determine the potential to 1) defer, reduce, and/or eliminate infrastructure requirements, and 2) significantly mitigate project risk by reducing the potential and impact of single point failures. The inventory of Hanford waste slated for processing and disposition as LAW is currently managed as high-level waste (HLW), i.e., the separation of fission products and other radionuclides has not commenced. A significant inventory of this waste (over 20M gallons) is in the form of precipitated saltcake maintained in single shell tanks, many of which are identified as potential leaking tanks. Retrieval and transport (as a liquid) must be staged within the waste feed delivery capability established by site infrastructure and WTP. Near Source treatment, if employed, would provide for the separation and stabilization processing necessary for waste located in remote farms (wherein most of the leaking tanks reside) significantly earlier than currently projected. Near Source treatment is intended to address the currently accepted site risk and also provides means to mitigate future issues likely to be faced over the coming decades. This paper

  20. Radioactive waste characterisation by neutron activation

    Nicol, Tangi

    2016-01-01

    Nuclear activities produce radioactive wastes classified following their radioactive level and decay time. an accurate characterization is necessary for efficient classification and management. Medium and high level wastes containing long lived radioactive isotopes will be stored in deep geological storage for hundreds of thousands years. at the end of this period, it is essential to ensure that the wastes do not represent any risk for humans and environment, not only from radioactive point of view, but also from stable toxic chemicals. This PhD thesis concerns the characterization of toxic chemicals and nuclear material in radioactive waste, by using neutron activation analysis, in the frame of collaboration between the Nuclear Measurement Laboratory of CEA Cadarache, France, and the Institute of Nuclear Waste Management and Reactor Safety of the research center, FZJ (Forschungszentrum Juelich GmbH), Germany. The first study is about the validation of the numerical model of the neutron activation cell MEDINA (FZJ), using MCNP Monte Carlo transport code. Simulations and measurements of prompt capture gamma rays from small samples measured in MEDINA have been compared for a number of elements of interest (beryllium, aluminum, chlorine, copper, selenium, strontium, and tantalum). The comparison was performed using different nuclear databases, resulting in satisfactory agreement and validating simulation in view of following studies. Then, the feasibility of fission delayed gamma-ray measurements of "2"3"9Pu and "2"3"5U in 225 L waste drums has been studied, considering bituminized or concrete matrixes representative of wastes produced in France and Germany. The delayed gamma emission yields were first determined from uranium and plutonium metallic samples measurements in REGAIN, the neutron activation cell of LMN, showing satisfactory consistency with published data. The useful delayed gamma signals of "2"3"9Pu and "2"3"5U, homogeneously distributed in the 225 L

  1. Effect of light energy on peroxide tooth bleaching.

    Luk, Karen; Tam, Laura; Hubert, Manfred

    2004-02-01

    Light-activated bleaching is a method of tooth whitening. The authors conducted a study to compare the whitening effects and tooth temperature changes induced by various combinations of peroxide bleaches and light sources. The authors randomly assigned 250 extracted human teeth halves into experimental groups (n = 10). A placebo gel (control), a 35 percent hydrogen peroxide or a 10 percent carbamide peroxide bleach was placed on the tooth surface and was irradiated with no light (control); a halogen curing light; an infrared, or IR, light; an argon laser; or a carbon dioxide, or CO2, laser. Color changes were evaluated immediately, one day and one week after treatment using a value-oriented shade guide and an electronic dental color analyzer. The outer enamel and inner dentin surface temperatures were monitored before and immediately after each 30-second application of light using a thermocouple thermometer. Color and temperature changes were significantly affected by an interaction of the bleach and light variables. The application of lights significantly improved the whitening efficacy of some bleach materials, but it caused significant temperature increases in the outer and inner tooth surfaces. The IR and CO2 laser lights caused the highest tooth temperature increases. Dentists performing an in-office bleaching technique with the use of an additional light source to accelerate tooth whitening should consider the specific bleaching agent being used, as well as the potential risks of heating teeth. A specific combination of bleach and light that demonstrates good color change and little temperature rise should be selected for in-office tooth bleaching.

  2. Atmospheric Pressure Plasma Jet as an Accelerator of Tooth Bleaching

    Vedran Šantak

    2014-01-01

    Full Text Available Objective: To study the effect of atmospheric pressure plasma (APP jet as a potential accelerator of the degradation of hydrogen peroxide in bleaching gels which could lead to better and faster bleaching. Material and Methods: 25 pastilles of hydroxylapatite were colored in green tea for 8 hours and were randomly divided into five groups (n = 5. The bleaching process was performed with 30% and 40% hydrogen peroxide (HP gel alone and in conjunction with helium APP jet. During the bleaching treatment, optical emission spectroscopy and non-contact surface temperature measurement using pyrometer were performed. Color of the pastilles was determined by a red– green–blue (RGB colorimeter. PH values of bleaching gels were measured before and after the plasma treatment on additional 10 pastilles using a pH meter with contact pH electrode. Results: The color measurements of pastilles before and after the treatment showed that treatment with APP jet improved the bleaching effect by 32% and 15% in the case of 30 % and 40% HP gel. Better results were obtained approximately six times faster than with a procedure suggested by the bleaching gel manufacturer. Optical emission spectroscopy proved that plasma has a chemically active role on the gel. After the APP treatment, pH values of bleaching gels dropped to about 50–75% of their initial value while the surface temperature increased by 8–10˚C above baseline. Conclusion: The use of plasma jet provides more effective bleaching results in a shorter period of time without a significant temperature increase which may cause damage of the surrounding tissue.

  3. Transporting Radioactive Waste: An Engineering Activity. Grades 5-12.

    HAZWRAP, The Hazardous Waste Remedial Actions Program.

    This brochure contains an engineering activity for upper elementary, middle school, and high school students that examines the transportation of radioactive waste. The activity is designed to inform students about the existence of radioactive waste and its transportation to disposal sites. Students experiment with methods to contain the waste and…

  4. Enamel alteration following tooth bleaching and remineralization.

    Coceska, Emilija; Gjorgievska, Elizabeta; Coleman, Nichola J; Gabric, Dragana; Slipper, Ian J; Stevanovic, Marija; Nicholson, John W

    2016-06-01

    The purpose of this study was to compare the effects of professional tooth whitening agents containing highly concentrated hydrogen peroxide (with and without laser activation), on the enamel surface; and the potential of four different toothpastes to remineralize any alterations. The study was performed on 50 human molars, divided in two groups: treated with Opalescence(®) Boost and Mirawhite(®) Laser Bleaching. Furthermore, each group was divided into five subgroups, a control one and 4 subgroups remineralized with: Mirasensitive(®) hap+, Mirawhite(®) Gelleѐ, GC Tooth Mousse™ and Mirafluor(®) C. The samples were analysed by SEM/3D-SEM-micrographs, SEM/EDX-qualitative analysis and SEM/EDX-semiquantitative analysis. The microphotographs show that both types of bleaching cause alterations: emphasized perikymata, erosions, loss of interprizmatic substance; the laser treatment is more aggressive and loss of integrity of the enamel is determined by shearing off the enamel rods. In all samples undergoing remineralization deposits were observed, those of toothpastes based on calcium phosphate technologies seem to merge with each other and cover almost the entire surface of the enamel. Loss of integrity and minerals were detected only in the line-scans of the sample remineralized with GC Tooth Mousse™. The semiquantitative EDX analysis of individual elements in the surface layer of the enamel indicates that during tooth-bleaching with HP statistically significant loss of Na and Mg occurs, whereas the bleaching in combination with a laser leads to statistically significant loss of Ca and P. The results undoubtedly confirm that teeth whitening procedures lead to enamel alterations. In this context, it must be noted that laser bleaching is more aggressive for dental substances. However, these changes are reversible and can be repaired by application of remineralization toothpastes. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  5. Improvement in rice straw pulp bleaching effluent quality by incorporating oxygen delignification stage prior to elemental chlorine-free bleaching.

    Kaur, Daljeet; Bhardwaj, Nishi K; Lohchab, Rajesh Kumar

    2017-10-01

    Environmental degradation by industrial and other developmental activities is alarming for imperative environmental management by process advancements of production. Pulp and paper mills are now focusing on using nonwood-based raw materials to protect forest resources. In present study, rice straw was utilized for pulp production as it is easily and abundantly available as well as rich in carbohydrates (cellulose and hemicelluloses). Soda-anthraquinone method was used for pulp production as it is widely accepted for agro residues. Bleaching process during paper production is the chief source of wastewater generation. The chlorophenolic compounds generated during bleaching are highly toxic, mutagenic, and bioaccumulative in nature. The objectives of study were to use oxygen delignification (ODL) stage prior to elemental chlorine-free (ECF) bleaching to reduce wastewater load and to study its impact on bleached pulp characteristics. ODL stage prior to ECF bleaching improved the optical properties of pulp in comparison to only ECF bleaching. When ODL stage was incorporated prior to bleaching, the tensile index and folding endurance of the pulp were found to be 56.6 ± 1.5 Nm/g and 140, respectively, very high in comparison to ECF alone. A potential reduction of 51, 57, 43, and 53% in BOD 3 , COD, color, and AOX, respectively was observed on adding the ODL stage compared to ECF only. Generation of chlorophenolic compounds was reduced significantly. Incorporation of ODL stage prior to bleaching was found to be highly promising for reducing the toxicity of bleaching effluents and may lead to better management of nearby water resources. Graphical abstract ᅟ.

  6. Low and medium activity solid wastes processing and encapsulation

    Taillard, D.; Claes, J.; Hennart, D.

    1983-01-01

    This work, carried out under contract with the European Atomic Energy Community, describes the techniques in use for waste management. The activity of low and medium activity solid wastes is from few curies to few tens of curies per cubic meter, they are produced by nuclear facilities and are often complex mixtures. Radioactive wastes are characterized and processing and conditioning are described. Leaching, stability, mechanical resistance and radiolysis of encapsulated wastes are examined. Handling, storage and disposal are treated

  7. The very-low activity waste storage facility. A new waste management system

    2006-01-01

    Very-low activity wastes have a radioactivity level close to the natural one. This category of waste is taken into consideration by the French legislation and their storage is one of their point of achievement. This document gives a complete overview of the principles of storage implemented at the storage center for very-low activity wastes (CSTFA) sited in the Aube departement in the vicinity of the storage center for low- and intermediate activity wastes: storage concept, wastes confinement, center organization, environmental monitoring. (J.S.)

  8. Regulation of higher-activity NARM wastes by EPA

    Bandrowski, M.S.

    1988-01-01

    The US Environmental Protection Agency (EPA) is currently developing standards for the disposal of low-level radioactive waste (LLW). As part of this Standard, EPA is including regulations for the disposal of naturally occurring and accelerator-produced radioactive material (NARM) wastes not covered under the Atomic Energy Act (AEA). The regulations will cover only higher-activity NARM wastes, defined as NARM waste with specific activity exceeding two nanocuries per gram. The proposed regulations will specify that NARM wastes exceeding the above limits, except for specific exempted items, must be disposed of in regulated radioactive waste disposal facilities. The proposed EPA regulations for NARM wastes will be discussed, as well as the costs and benefits of the regulation, how it will be implemented by EPA, and the rationale for covering only higher-activity NARM wastes exceeding two nanocuries per gram

  9. Evaluation of the bleached human enamel by Scanning Electron Microscopy

    Miranda, Carolina Baptista; Pagani, Clovis; Benetti, Ana Raquel

    2005-01-01

    Since bleaching has become a popular procedure, the effect of peroxides on dental hard tissues is of great interest in research. Purpose: The aim of this in vitro study was to perform a qualitative analysis of the human enamel after the application of in-office bleaching agents, using Scanning......: 2h); G3- four 2-hour exposures to 35% carbamide peroxide (total exposure: 8h); G4- two applications of 35% hydrogen peroxide, which was light-activated with halogen lamp at 700mW/cm² during 7min and remained in contact with enamel for 20min (total exposure: 40min). All bleaching treatments adopted...... analysis performing gold sputter coating under vacuum and were examined using 15kV at 500x and 2000x magnification. Results: Morphological alterations on the enamel surface were similarly detected after bleaching with either 35% carbamide peroxide or 35% hydrogen peroxide. Surface porosities were...

  10. Characterization of low and medium active wastes

    Saas, A.

    1993-01-01

    For several years now, research on raw or packaged waste characterization has been carried out in France. Qualitative or quantitative analysis are given of radionuclides present in already packaged waste (including badly packaged waste) or in unpackaged waste; as far as possible, evaluation of the main physico-mechanical and confinement characteristics

  11. Radioactive Waste Management Program Activities in Croatia

    Matanic, R.

    2000-01-01

    The concept of radioactive waste management in Croatia comprises three major areas: management of low and intermediate level radioactive waste (LILRW), spent fuel management and decommissioning. All the work regarding radioactive waste management program is coordinated by Hazardous Waste Management Agency (APO) and Croatian Power Utility (HEP) in cooperation with other relevant institutions. Since the majority of work has been done in developing low and intermediate level radioactive waste management program, the paper will focus on this part of radioactive waste management, mainly on issues of site selection and characterization, repository design, safety assessment and public acceptance. A short description of national radioactive waste management infrastructure will also be presented. (author)

  12. Enamel alteration following tooth bleaching and remineralization

    Coceska, Emilija; Gjorgievska, Elizabeta; Coleman, Nichola; Gabric, Dragana; Slipper, Ian J.; Stevanovic, Marija; Nicholson, John

    2015-01-01

    The purpose of this study was to compare the effects of professional tooth whitening agents containing highly concentrated hydrogen peroxide (with and without laser activation), on the enamel surface; and the potential of four different toothpastes to remineralize any alterations.\\ud \\ud The study was performed on 50 human molars, divided in two groups: treated with Opalescence® Boost and Mirawhite® Laser Bleaching. Furthermore, each group was divided into five subgroups, a control one and 4 ...

  13. Coral reef bleaching: ecological perspectives

    Glynn, P. W.

    1993-03-01

    Coral reef bleaching, the whitening of diverse invertebrate taxa, results from the loss of symbiotic zooxanthellae and/or a reduction in photosynthetic pigment concentrations in zooxanthellae residing within the gastrodermal tissues of host animals. Of particular concern are the consequences of bleaching of large numbers of reef-building scleractinian corals and hydrocorals. Published records of coral reef bleaching events from 1870 to the present suggest that the frequency (60 major events from 1979 to 1990), scale (co-occurrence in many coral reef regions and often over the bathymetric depth range of corals) and severity (>95% mortality in some areas) of recent bleaching disturbances are unprecedented in the scientific literature. The causes of small scale, isolated bleaching events can often be explained by particular stressors (e.g., temperature, salinity, light, sedimentation, aerial exposure and pollutants), but attempts to explain large scale bleaching events in terms of possible global change (e.g., greenhouse warming, increased UV radiation flux, deteriorating ecosystem health, or some combination of the above) have not been convincing. Attempts to relate the severity and extent of large scale coral reef bleaching events to particular causes have been hampered by a lack of (a) standardized methods to assess bleaching and (b) continuous, long-term data bases of environmental conditions over the periods of interest. An effort must be made to understand the impact of bleaching on the remainder of the reef community and the long-term effects on competition, predation, symbioses, bioerosion and substrate condition, all factors that can influence coral recruitment and reef recovery. If projected rates of sea warming are realized by mid to late AD 2000, i.e. a 2°C increase in high latitude coral seas, the upper thermal tolerance limits of many reef-building corals could be exceeded. Present evidence suggests that many corals would be unable to adapt

  14. Quarterly Briefing Book on Environmental and Waste Management Activities

    Brown, M.C.

    1991-06-01

    The purpose of the Quarterly Briefing Book on Environmental and Waste Management Activities is to provide managers and senior staff at the US Department of Energy-Richland Operations Office and its contractors with timely and concise information on Hanford Site environmental and waste management activities. Each edition updates the information on the topics in the previous edition, deletes those determined not to be of current interest, and adds new topics to keep up to date with changing environmental and waste management requirements and issues. Section A covers current waste management and environmental restoration issues. In Section B are writeups on national or site-wide environmental and waste management topics. Section C has writeups on program- and waste-specific environmental and waste management topics. Section D provides information on waste sites and inventories on the site. 15 figs., 4 tabs

  15. Quarterly Briefing Book on Environmental and Waste Management Activities

    Brown, M.C.

    1991-06-01

    The purpose of the Quarterly Briefing Book on Environmental and Waste Management Activities is to provide managers and senior staff at the US Department of Energy-Richland Operations Office and its contractors with timely and concise information on Hanford Site environmental and waste management activities. Each edition updates the information on the topics in the previous edition, deletes those determined not to be of current interest, and adds new topics to keep up to date with changing environmental and waste management requirements and issues. Section A covers current waste management and environmental restoration issues. In Section B are writeups on national or site-wide environmental and waste management topics. Section C has writeups on program- and waste-specific environmental and waste management topics. Section D provides information on waste sites and inventories on the site. 15 figs., 4 tabs.

  16. High-active waste (HAW) data report

    Duijves, K.A.

    1991-06-01

    Data are presented from the High Active Waste (HAW) experiment, a large-scale, in situ test being performed underground at the Asse salt mine in Remlingen, FRG. These data include selected field information, the test configuration, instrumentation activities and comprehensive results from a large number of gauges. The results are measured data obtained from gap meters, thermocouples, linear displacement trans-ducers, extensometers, inclinometers and pressure gauges. Data certification practices have been described together with the quality assurance of the data reduction and of the data base management system. The experiment began on November 8, 1988 and will continue for five years. Data in this report cover the period from July 1st, 1990 to December 31, 1990. (author). 4 refs.; 100 figs.; 8 tabs

  17. An innovative chairside bleaching protocol for treating stained dentition: initial results.

    Miara, P

    2000-09-01

    For years, investigators have attempted to develop a predictable means of bleaching pathologically and nonpathologically stained dentition. While previous efforts have modified the concentration of the bleaching material, the duration of the procedure, and the manner by which the bleaching agent is activated, the ability to affect a significant shade improvement remains an elusive objective. This article demonstrates an innovative technique used to influence the penetration of oxygen ions into the tooth enamel, which may resolve this clinical dilemma.

  18. Aube very low activity waste storage Centre. Annual report 2009

    2010-01-01

    After a presentation of the ANDRA (the French national agency for radioactive waste management), its role and missions, its sites, its strategy with respect to a sustainable development, this report contains a description of waste storage installations and key figures of the activity in 2009 (origin and nature of very low activity wastes, brief description of the Aube centre installations, stored volumes, performed works). It describes arrangements related to security, safety and radioprotection, presents results of the radiological survey activity performed in the environment and on wastes, and activities related to public information

  19. Urine: Waste product or biologically active tissue?

    2018-03-01

    Historically, urine has been viewed primarily as a waste product with little biological role in the overall health of an individual. Increasingly, data suggest that urine plays a role in human health beyond waste excretion. For example, urine might act as an irritant and contribute to symptoms through interaction with-and potential compromise of-the urothelium. To explore the concept that urine may be a vehicle for agents with potential or occult bioactivity and to discuss existing evidence and novel research questions that may yield insight into such a role, the National Institute of Diabetes and Digestive and Kidney Disease invited experts in the fields of comparative evolutionary physiology, basic science, nephrology, urology, pediatrics, metabolomics, and proteomics (among others) to a Urinology Think Tank meeting on February 9, 2015. This report reflects ideas that evolved from this meeting and current literature, including the concept of urine quality, the biological, chemical, and physical characteristics of urine, including the microbiota, cells, exosomes, pH, metabolites, proteins, and specific gravity (among others). Additionally, the manuscript presents speculative, and hopefully testable, ideas about the functional roles of urine constituents in health and disease. Moving forward, there are several questions that need further understanding and pursuit. There were suggestions to consider actively using various animal models and their biological specimens to elaborate on basic mechanistic information regarding human bladder dysfunction. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

  20. Improving radioactive waste management: an overview of the Environmental Protection Agency's low-activity waste effort.

    Schultheisz, Daniel J; Czyscinski, Kenneth S; Klinger, Adam D

    2006-11-01

    Radioactive waste disposal in the United States is marked by a fragmented regulatory system, with requirements that often focus on the origin or statutory definition of the waste, rather than the hazard of the material in question. It may be possible to enhance public protection by moving toward a system that provides disposal options appropriate for the hazard presented by the waste in question. This paper summarizes aspects of an approach focusing on the potential use, with appropriate conditions, of Resource Conservation and Recovery Act Subtitle-C hazardous waste landfills for disposal of "low-activity" wastes and public comments on the suggested approach.

  1. Waste management activities and carbon emissions in Africa

    Couth, R.; Trois, C.

    2011-01-01

    This paper summarizes research into waste management activities and carbon emissions from territories in sub-Saharan Africa with the main objective of quantifying emission reductions (ERs) that can be gained through viable improvements to waste management in Africa. It demonstrates that data on waste and carbon emissions is poor and generally inadequate for prediction models. The paper shows that the amount of waste produced and its composition are linked to national Gross Domestic Product (GDP). Waste production per person is around half that in developed countries with a mean around 230 kg/hd/yr. Sub-Saharan territories produce waste with a biogenic carbon content of around 56% (+/-25%), which is approximately 40% greater than developed countries. This waste is disposed in uncontrolled dumps that produce large amounts of methane gas. Greenhouse gas (GHG) emissions from waste will rise with increasing urbanization and can only be controlled through funding mechanisms from developed countries.

  2. Waste Treatment Technology Process Development Plan For Hanford Waste Treatment Plant Low Activity Waste Recycle

    McCabe, Daniel J.; Wilmarth, William R.; Nash, Charles A.

    2013-01-01

    The purpose of this Process Development Plan is to summarize the objectives and plans for the technology development activities for an alternative path for disposition of the recycle stream that will be generated in the Hanford Waste Treatment Plant Low Activity Waste (LAW) vitrification facility (LAW Recycle). This plan covers the first phase of the development activities. The baseline plan for disposition of this stream is to recycle it to the WTP Pretreatment Facility, where it will be concentrated by evaporation and returned to the LAW vitrification facility. Because this stream contains components that are volatile at melter temperatures and are also problematic for the glass waste form, they accumulate in the Recycle stream, exacerbating their impact on the number of LAW glass containers. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to acceptable concentrations in the LAW glass, and reducing the halides in the Recycle is a key component of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, this stream does not have a proven disposition path, and resolving this gap becomes vitally important. This task seeks to examine the impact of potential future disposition of this stream in the Hanford tank farms, and to develop a process that will remove radionuclides from this stream and allow its diversion to another disposition path, greatly decreasing the LAW vitrification mission duration and quantity of glass waste. The origin of this LAW Recycle stream will be from the Submerged Bed Scrubber (SBS) and the Wet Electrostatic Precipitator (WESP) from the LAW melter off-gas system. The stream is expected to be a dilute salt solution with near neutral pH, and will likely contain some insoluble solids from melter carryover or precipitates of scrubbed components (e.g. carbonates). The soluble

  3. Wastes Characterisation from Foundry Activities on European Level

    Andres, I.; Ruiz, C.; Ibanez, R.; Viguri, J.; Irabien, A.

    1999-01-01

    This work presents The results of the eco toxicological characterisation of 22 defined wastes from steel foundry activities. The wastes have been selected from three processes, steel mill (smelting). sand casting and cleaning and finishing of steel products,with the common characteristics of represent an important industrial activity in the area and generated the wastes considered in this study. The eco toxicological characterisation obtained applying the Spanish regulations on hazardous waste is compared to the hazardous attributions considered by the European Union in order to characterise a waste as hazardous (non hazardous). The results allow to conclude that a acceptable concordance between both methodologies is reached and remark the need to split the broad generic types of wastes given by the Spanish regulation (Eco toxic / non eco toxic) into clearly identifiable specific types of waste

  4. Activation of waste brewer's yeast Saccharomyces cerevisiae for bread production

    Popov Stevan D.; Dodić Siniša N.; Mastilović Jasna S.; Dodić Jelena M.; Popov-Raljić Jovanka V.

    2005-01-01

    The waste brewer's yeast S. cerevisiae (activated and non-activated) was compared with the commercial baker's yeast regarding the volume of developed gas in dough, volume and freshness stability of produced bread. The activation of waste brewer's yeast resulted in the increased volume of developed gas in dough by 100% compared to non-activated brewer's yeast, and the obtained bread is of more stable freshness compared to bread produced with baker's yeast. The activation of BY affects positive...

  5. Permitting plan for the immobilized low-activity waste project

    Deffenbaugh, M.L.

    1997-01-01

    This document addresses the environmental permitting requirements for the transportation and interim storage of the Immobilized Low-Activity Waste (ILAW) produced during Phase 1 of the Hanford Site privatization effort. Tri-Party Agreement (TPA) Milestone M-90 establishes a new major milestone, and associated interim milestones and target dates, governing acquisition and/or modification of facilities necessary for: (1) interim storage and disposal of Tank Waste Remediation Systems (TWRS) immobilized low-activity tank waste (ILAW) and (2) interim storage of TWRS immobilized HLW (IHLW) and other canistered high-level waste forms. Low-activity waste (LAW), low-level waste (LLW), and high-level waste (HLW) are defined by the TWRS, Hanford Site, Richland, Washington, Final Environmental Impact Statement (EIS) DOE/EIS-0189, August 1996 (TWRS, Final EIS). By definition, HLW requires permanent isolation in a deep geologic repository. Also by definition, LAW is ''the waste that remains after separating from high-level waste as much of the radioactivity as is practicable that when solidified may be disposed of as LLW in a near-surface facility according to the NRC regulations.'' It is planned to store/dispose of (ILAW) inside four empty vaults of the five that were originally constructed for the Group Program. Additional disposal facilities will be constructed to accommodate immobilized LLW packages produced after the Grout Vaults are filled. The specifications for performance of the low-activity vitrified waste form have been established with strong consideration of risk to the public. The specifications for glass waste form performance are being closely coordinated with analysis of risk. RL has pursued discussions with the NRC for a determination of the classification of the Hanford Site's low-activity tank waste fraction. There is no known RL action to change law with respect to onsite disposal of waste

  6. Efficacy and cytotoxicity of a bleaching gel after short application times on dental enamel.

    Soares, Diana Gabriela; Ribeiro, Ana Paula Dias; da Silveira Vargas, Fernanda; Hebling, Josimeri; de Souza Costa, Carlos Alberto

    2013-11-01

    This study aimed to evaluate and correlate the efficacy and cytotoxicity of a 35 % hydrogen peroxide (HP) bleaching gel after different application times on dental enamel. Enamel/dentin disks in artificial pulp chambers were placed in wells containing culture medium. The following groups were formed: G1, control (no bleaching); G2 and G3, three or one 15-min bleaching applications, respectively; and G4 and G5, three or one 5-min bleaching applications, respectively. Extracts (culture medium with bleaching gel components) were applied for 60 min on cultured odontoblast-like MDPC-23 cells. Cell metabolism (methyl tetrazolium assay) (Kruskal-Wallis/Mann-Whitney; α = 5 %) and cell morphology (scanning electron microscopy) were analyzed immediately after the bleaching procedures and the trans-enamel and trans-dentinal HP diffusion quantified (one-way analysis of variance/Tukey's test; α = 5 %). The alkaline phosphatase (ALP) activity was evaluated 24 h after the contact time of the extracts with the cells (Kruskal-Wallis/Mann-Whitney; α = 5 %). Tooth color was analyzed before and 24 h after bleaching using a spectrophotometer according to the Commission Internationale de l'Eclairage L*a*b* system (Kruskal-Wallis/Mann-Whitney; α = 0.05). Significant difference (p 0.05). The lowest amount of HP diffusion was observed in G5 (p 0.05). HP diffusion through dental tissues and its cytotoxic effects were proportional to the contact time of the bleaching gel with enamel. However, shorter bleaching times reduced bleaching efficacy. Shortening the in-office tooth bleaching time could be an alternative to minimize the cytotoxic effects of this clinical procedure to pulp tissue. However, the reduced time of bleaching agent application on enamel may not provide adequate esthetic outcome.

  7. International Symposium on Disposal of Low Activity Radioactive Waste, Cordoba, Spain, 13-17 December 2004

    2004-01-01

    The topical issues addressed by the symposium were: policies and strategies for low activity radioactive waste; very low activity radioactive waste; low activity radioactive waste from decommissioning; long lived low activity radioactive waste and other materials; and unique low activity radioactive waste.

  8. Predicting the degradability of waste activated sludge.

    Jones, Richard; Parker, Wayne; Zhu, Henry; Houweling, Dwight; Murthy, Sudhir

    2009-08-01

    The objective of this study was to identify methods for estimating anaerobic digestibility of waste activated sludge (WAS). The WAS streams were generated in three sequencing batch reactors (SBRs) treating municipal wastewater. The wastewater and WAS properties were initially determined through simulation of SBR operation with BioWin (EnviroSim Associates Ltd., Flamborough, Ontario, Canada). Samples of WAS from the SBRs were subsequently characterized through respirometry and batch anaerobic digestion. Respirometry was an effective tool for characterizing the active fraction of WAS and could be a suitable technique for determining sludge composition for input to anaerobic models. Anaerobic digestion of the WAS revealed decreasing methane production and lower chemical oxygen demand removals as the SRT of the sludge increased. BioWin was capable of accurately describing the digestion of the WAS samples for typical digester SRTs. For extended digestion times (i.e., greater than 30 days), some degradation of the endogenous decay products was assumed to achieve accurate simulations for all sludge SRTs.

  9. Novel Activated Carbons from Agricultural Wastes and their Characterization

    S. Karthikeyan

    2008-01-01

    Full Text Available Solid waste disposal has become a major problem in India, Either it has to be disposed safely or used for the recovery of valuable materials as agricultural wastes like turmeric waste, ferronia shell waste, jatropha curcus seed shell waste, delonix shell waste and ipomea carnia stem. Therefore these wastes have been explored for the preparation of activated carbon employing various techniques. Activated carbons prepared from agricultural solid wastes by chemical activation processes shows excellent improvement in the surface characteristics. Their characterization studies such as bulk density, moisture content, ash content, fixed carbon content, matter soluble in water, matter soluble in acid, pH, decolourising power, phenol number, ion exchange capacity, ion content and surface area have been carried out to assess the suitability of these carbons as absorbents in the water and wastewater. For anionic dyes (reactive, direct, acid a close relationship between the surface area and surface chemical groups of the modified activated carbon and percentage of dye removal by adsorption can be observed. Cationic dyes large amount of surface chemical groups present in the sample (mainly carboxylic, anhydrides, lactones and phenols etc. are good anchoring sites for adsorption. The present study reveals the recovery of valuable adsorbents from readily and cheaply available agriculture wastes.

  10. Waste minimization activity report for 1991

    Shoemaker, J.D.

    1992-01-01

    This is a waste reduction report for the Lawrence Livermore National Laboratory (LLNL) for 1991. The report covers the Main Site at Livermore and Site 300. Each research program at LLNL is described by its operation, administrative procedures, and waste minimization. Examples of the programs at LLNL are biomedical and environmental research, chemistry and materials science, and energy program and earth sciences. (MB)

  11. Waste Treatment Technology Process Development Plan For Hanford Waste Treatment Plant Low Activity Waste Recycle

    McCabe, Daniel J.; Wilmarth, William R.; Nash, Charles A.

    2013-08-29

    The purpose of this Process Development Plan is to summarize the objectives and plans for the technology development activities for an alternative path for disposition of the recycle stream that will be generated in the Hanford Waste Treatment Plant Low Activity Waste (LAW) vitrification facility (LAW Recycle). This plan covers the first phase of the development activities. The baseline plan for disposition of this stream is to recycle it to the WTP Pretreatment Facility, where it will be concentrated by evaporation and returned to the LAW vitrification facility. Because this stream contains components that are volatile at melter temperatures and are also problematic for the glass waste form, they accumulate in the Recycle stream, exacerbating their impact on the number of LAW glass containers. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to acceptable concentrations in the LAW glass, and reducing the halides in the Recycle is a key component of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, this stream does not have a proven disposition path, and resolving this gap becomes vitally important. This task seeks to examine the impact of potential future disposition of this stream in the Hanford tank farms, and to develop a process that will remove radionuclides from this stream and allow its diversion to another disposition path, greatly decreasing the LAW vitrification mission duration and quantity of glass waste. The origin of this LAW Recycle stream will be from the Submerged Bed Scrubber (SBS) and the Wet Electrostatic Precipitator (WESP) from the LAW melter off-gas system. The stream is expected to be a dilute salt solution with near neutral pH, and will likely contain some insoluble solids from melter carryover or precipitates of scrubbed components (e.g. carbonates). The soluble

  12. BIOLOGICALLY ACTIVE SUBSTANCES OF SPIRIT PRODUCTION WASTE

    A. S. Kayshev

    2014-01-01

    %. Proteins of Biobardins are inhomogeneous by their molecular mass and solubility in water and salt solutions. Both Biobardins are characterized by the mineral composition identical to the composition of relative distillers grains phase. During the experiments on animals practical nontoxicity and hepatotoxicity absence of Biobardins were established. Using prednisole stomach ulcers of rats as a model a signified gastroprotective influence of Biobardin BM was established. It was shown in a reduction of the number of ulcerative and hemorrhagic blennoses, secretory and proteolytic functions of stomach. Models of electroreduction, peroxide oxidation of lipids (POL of oleic acid, POL of egg yolk, and rats' hepatitis proved signified antioxidant activity of Biobardin UL which exceeds comparable substances by 8,3-30,1%; absence of fatty degeneration of rats' lever was shown under the influence of Biobardin UL. Composition of Biobardin BM and Biobardin UL pills as rational medicine form was justified and designed. Distillers grains processing allows reduction of industrial waste toxicity index – chemical consumption of oxygen (CCO by 74%, making distillers grains ecologically-friendly waste water.

  13. Anemone bleaching increases the metabolic demands of symbiont anemonefish.

    Norin, Tommy; Mills, Suzanne C; Crespel, Amélie; Cortese, Daphne; Killen, Shaun S; Beldade, Ricardo

    2018-04-11

    Increased ocean temperatures are causing mass bleaching of anemones and corals in the tropics worldwide. While such heat-induced loss of algal symbionts (zooxanthellae) directly affects anemones and corals physiologically, this damage may also cascade on to other animal symbionts. Metabolic rate is an integrative physiological trait shown to relate to various aspects of organismal performance, behaviour and locomotor capacity, and also shows plasticity during exposure to acute and chronic stressors. As climate warming is expected to affect the physiology, behaviour and life history of animals, including ectotherms such as fish, we measured if residing in bleached versus unbleached sea anemones ( Heteractis magnifica ) affected the standard (i.e. baseline) metabolic rate and behaviour (activity) of juvenile orange-fin anemonefish ( Amphiprion chrysopterus ) . Metabolic rate was estimated from rates of oxygen uptake [Formula: see text], and the standard metabolic rate [Formula: see text] of anemonefish from bleached anemones was significantly higher by 8.2% compared with that of fish residing in unbleached anemones, possibly due to increased stress levels. Activity levels did not differ between fish from bleached and unbleached anemones. As [Formula: see text] reflects the minimum cost of living, the increased metabolic demands may contribute to the negative impacts of bleaching on important anemonefish life history and fitness traits observed previously (e.g. reduced spawning frequency and lower fecundity). © 2018 The Author(s).

  14. Active waste disposal monitoring at the Radioactive Waste Management Complex, Idaho National Engineering Laboratory

    Hubbell, J.M.

    1990-10-01

    This report describes an active waste disposal monitoring system proposed to be installed beneath the low-level radioactive disposal site at the Radioactive Waste Management Complex (RWMC), Idaho National Engineering Laboratory, Idaho. The monitoring instruments will be installed while the waste is being disposed. Instruments will be located adjacent to and immediately beneath the disposal area within the unsaturated zone to provide early warning of contaminant movement before contaminants reach the Snake River Plain Aquifer. This study determined the optimum sampling techniques using existing monitoring equipment. Monitoring devices were chosen that provide long-term data for moisture content, movement of gamma-emitting nuclides, and gas concentrations in the waste. The devices will allow leachate collection, pore-water collection, collection of gasses, and access for drilling through and beneath the waste at a later time. The optimum monitoring design includes gas sampling devices above, within, and below the waste. Samples will be collected for methane, tritium, carbon dioxide, oxygen, and volatile organic compounds. Access tubes will be utilized to define the redistribution of radionuclides within, above, and below the waste over time and to define moisture content changes within the waste using spectral and neutron logging, respectively. Tracers will be placed within the cover material and within waste containers to estimate transport times by conservative chemical tracers. Monitoring the vadose zone below, within, and adjacent to waste while it is being buried is a viable monitoring option. 12 refs., 16 figs., 1 tab

  15. Treatment of rod shaped intermediate active waste

    Graf, A.; Blase, F.; Dirks, F.; Valencia, L.

    2002-01-01

    The Central Decontamination Operation Department (HDB) of the Research Center Karlsruhe operates facilities for the disposal of radioactive waste. In general, their objective is to reduce the volume of the radioactive waste and to obtain waste products suitable for repository storage. One of the central facilities of the HDB is the intermediate level waste (ILW) scrapping facility which processes intermediate level waste. Since the ILW scrapping facility was not large enough to handle radioactive waste coming from the dismantling and operating of nuclear facilities, HDB expanded and built a larger hot cell. It contains a hydraulically driven metal cutter with a guiding channel and a high pressure compactor. A major task in the hot cell of the ILW scrapping facility is disposing of fuel boxes. These are cut in pieces and scrapped, which is a unique technique in Germany for fuel box disposal. HDB's experiences in disposing of radioactive waste in the ILW scrapping facility will described in detail, with special emphasis on the handling of rod shaped components. (author)

  16. Safe management of waste from health-care activities

    Pruess, A.; Giroult, E.; Rushbrook, P.

    1999-01-01

    The waste produced in the course of health-care activities, from contaminated needles to radioactive isotopes, carries a greater potential for causing infection and injury than any other type of waste, and inadequate or inappropriate management is likely to have serious public health consequences and deleterious effects on the environment. This handbook - the result of extensive international consultation and collaboration - provides comprehensive guidance on safe, efficient, and environmentally sound methods for the handling and disposal of health-care wastes. The various categories of waste are clearly defined and the particular hazards that each poses are described. Considerable prominence is given to the careful planning that is essential for the success of waste management; workable means of minimizing waste production are outlined and the role of reuse and recycling of waste is discussed. Most of the text, however, is devoted to the collection, segregation, storage, transport, and disposal of wastes. Details of containers for each category of waste, labelling of waste packages, and storage conditions are provided, and the various technologies for treatment of waste and disposal of final residues are discussed at length. Advice is given on occupational safety for all personnel involved with waste handling, and a separate chapter is devoted to the closely related topic of hospital hygiene and infection control. The handbook pays particular attention to basic processes and technologies that are not only safe but also affordable, sustainable, and culturally appropriate. For health-care settings in which resources are severely limited there is a separate chapter on minimal programmes; this summarizes all the simplest and least costly techniques that can be employed for the safe management of health-care wastes. The guide is aimed at public health managers and policy-makers, hospital managers, environmental health professionals, and all administrators with an

  17. Method to determine the activity concentration and total activity of radioactive waste

    Angeles C, A.

    2001-02-01

    A characteristic system of radioactive waste is described to determine the concentration of radionuclides activity and the total activity of bundles of radioactive waste. The system this integrated by three subsystems: - Elevator of drums. - Electromechanics. - Gamma spectroscopy. In the system it is analyzed waste of issuing gamma specifically, and this designed for materials of relative low density and it analyzes materials of cylindrical recipients

  18. Effects of hydrogen peroxide bleaching strips on tooth surface color, surface microhardness, surface and subsurface ultrastructure, and microchemical (Raman spectroscopic) composition.

    Duschner, Heinz; Götz, Hermann; White, Donald J; Kozak, Kathleen M; Zoladz, James R

    2006-01-01

    This study examined the effects of hydrogen peroxide tooth bleaching strips on the surface hardness and morphology of enamel and the ultrastructure and chemical composition of enamel and dentin in vitro. Sound human molars were ground and polished to prepare a uniform substrate for bleaching treatments. A cycling treatment methodology was employed which alternated ex vivo human salivary exposures with bleaching treatments under conditions of controlled temperature and durations of treatment. Bleaching treatments included commercial Crest Whitestrips bleaching strips, which utilize hydrogen peroxide in a gel as the in situ bleaching source at 6.0 and 6.5% concentrations of H2O2. Control treatments included an untreated group. Crest Whitestrips bleaching included treatment exposures simulating 2x the recommended clinical exposures (28 hours bleaching). Surface color measurements were taken prior to and following bleaching to ensure tooth bleaching activity. The effects of bleach on physical properties of enamel were assessed with microhardness measures. Ultrastructural effects were classified by surface and subsurface confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) techniques. In addition, the effects of bleaching on tooth microchemical composition was studied in different tooth regions by coincident assessment of Raman spectroscopic signature. Color assessments confirmed significant ex vivo tooth bleaching by Whitestrips. Surface microhardness and SEM measures revealed no deleterious effects on the enamel surfaces. CLSM micromorphological assessments supported the safety of hydrogen peroxide bleaching strips both on surface and subsurface enamel, DEJ, and dentin ultrastructure. Raman spectroscopy analysis demonstrated no obvious effects of bleaching treatments on the microchemical composition of enamel and dentin. These results confirm that tooth bleaching with hydrogen peroxide whitening strips does not produce changes in surface

  19. Quality checking task force destructive testing of active waste forms

    James, J.M.; Smith, D.L.

    1987-03-01

    The implications of sampling and testing of full size active packages of intermediate level wastes are summarised in this report. Sampling operations are technically feasible but a major difficulty will be the disposal of secondary waste. A literature survey indicated that destructive testing of wasteforms is not carried out as a routine operation in Europe or the USA. (author)

  20. Waste monitoring of the uranium ore processing activities in Romania

    Nica, L.

    2002-01-01

    The uranium ore processing activities at the Feldioara site produce a range of liquid and solid waste that are monitored. Liquids are treated through decantation, pH correction and uranium precipitation before their release into the environment. The solid waste is gathered into ore specific area and are covered regularly with clay materials. (author)

  1. Volume reduction through incineration of low-activity radioactive wastes

    Eymeri, J.; Gauthey, J.C.; Chaise, D.; Lafite, G.

    1993-01-01

    The aim of the waste treatment plant, designed by Technicatome (CEA) for an Indonesian Nuclear Research Center, is to reduce through incineration the volume of low-activity radioactive wastes such as technological solids (cotton, PVC, paper board), biological solids (animal bones) and liquids (cutting fluids...). The complete combustion is realized with a total air multi-fuel burner (liquid wastes) and flash pyrolysis-complete combustion (solid wastes). A two stage flue gas filtration system, a flue gas washing system, and an ash recovery system are used. A test platform has been built. 3 figs

  2. Hanford Immobilized Low-Activity Waste Product Acceptance Test Plan

    Peeler, D.

    1999-01-01

    'The Hanford Site has been used to produce nuclear materials for the U.S. Department of Energy (DOE) and its predecessors. A large inventory of radioactive and mixed waste, largely generated during Pu production, exists in 177 underground single- and double-shell tanks. These wastes are to be retrieved and separated into low-activity waste (LAW) and high-level waste (HLW) fractions. The DOE is proceeding with an approach to privatize the treatment and immobilization of Handord''s LAW and HLW.'

  3. Hanford Immobilized Low-Activity Waste Product Acceptance Test Plan

    Peeler, D.

    1999-06-22

    'The Hanford Site has been used to produce nuclear materials for the U.S. Department of Energy (DOE) and its predecessors. A large inventory of radioactive and mixed waste, largely generated during Pu production, exists in 177 underground single- and double-shell tanks. These wastes are to be retrieved and separated into low-activity waste (LAW) and high-level waste (HLW) fractions. The DOE is proceeding with an approach to privatize the treatment and immobilization of Handord''s LAW and HLW.'

  4. Activities in department of energy hazardous and mixed waste defense waste management

    Eyman, L.D.

    1988-01-01

    In January 1986, the U.S. Department of Energy (DOE) Office of Assistant Secretary for Defense Programs (DP) created the Hazardous Waste and Remedial Actions Division within the Office of Defense Waste and Transportation Management. The Oak Ridge Operations Office (ORO) was assigned the responsibility for supporting DOE Headquarters (HQ) in planning nationally integrated activities for Resource Conservation and Recovery Act/Comprehensive Environmental Response, Compensation, and Liability Act/Superfund Amendments and Reauthorization Act (RCRA/CERCLA/SARA) compliance. In turn, ORO created the Hazardous Waste Remedial Actions Program Support Contractor Office (HAZWRAPSCO) to assist with the expanded lead assignment. The HAZWRAPSCO activities are currently supported by three distinct DOE-HQ funding elements: the Environmental Restoration Program, the Hazardous Waste Compliance Technology Program, and the Hazardous Waste Research and Development R and D Program. The Environmental Restoration Program is discussed in the paper, entitled The DOE Defense Program for Environmental Restoration

  5. IDENTIFIKASI DAN UJI POTENSI BAKTERI LIPOLITIK DARI LIMBAH SBE (SPENT BLEACHING EARTH SEBAGAI AGEN BIOREMEDIASI

    Fitralia Elyza

    2016-03-01

    Full Text Available Limbah minyak kelapa sawit yang terbanyak adalah SBE (Spent Bleaching Earth, limbah ini mengandung residu minyak tinggi yang dapat mencemari lingkungan, 30% residu minyak pada limbah SBE dapat digunakan bakteri untuk pertumbuhannya, sehingga adanya bakteri mampu menjadi agen bioremediasi pencemaran SBE. Penelitian dilakukan untuk mendapatkan bakteri lipolitik sebagai agen potensial bioremediasi pada limbah SBE. Metode pengambilan sampel limbah SBE secara random sampling. Sampel tanah diambil secara acak dari beberapa titik area limbah SBE. Bakteri diisolasi dari sampel limbah SBE, kemudian dilakukan tahapan yaitu : pemurnian, seleksi, uji potensi, bakteri berpotensi mereduksi lipid dikarakterisasi dan diidentifikasi genusnya. Hasil penelitian menunjukkan bahwa Aktivitas enzim lipase yang tinggi menandakan bahwa bakteri lipolitik bekerja optimal merombak zat pencemar. Bakteri yang memiliki potensi sebagai agen bioremediasi terdiri dari genus Citrobacter (B1, Enterobacter (B2 dan Acinetobacter (B3. The most palm oil waste is SBE (Spent Bleaching Earth, this waste had many reduced lipid that got pollution for inviroments, Bacteria can use lipid from SBE as much as 30% for growed. So that consist of bacteria in SBE as a potensial agent for remediation. This study aims to obtain lipolytic bacteria as a potential agent of bioremediation. The method of sampling soil were taken at random from SBE waste, Bacteria were isolated from the SBE waste, then they were selected into steps : performed purification, selection, potential test, then characterized and identified it’s genus of potential bacteria. The results showed that the higest activity enzyme of lipolytic indicated that the lipolytic bacteria worked optimal for reduce polution. Bacteria had potential as a bioremediation agent consisting of genus Citrobacter (B1, Enterobacter (B2 and Acinetobacter (B3.

  6. New Insights on Degumming and Bleaching Process Parameters on The Formation of 3-Monochloropropane-1,2-Diol Esters and Glycidyl Esters in Refined, Bleached, Deodorized Palm Oil.

    Sim, Biow Ing; Muhamad, Halimah; Lai, Oi Ming; Abas, Faridah; Yeoh, Chee Beng; Nehdi, Imededdine Arbi; Khor, Yih Phing; Tan, Chin Ping

    2018-04-01

    This paper examines the interactions of degumming and bleaching processes as well as their influences on the formation of 3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters in refined, bleached and deodorized palm oil by using D-optimal design. Water degumming effectively reduced the 3-MCPDE content up to 50%. Acid activated bleaching earth had a greater effect on 3-MCPDE reduction compared to natural bleaching earth and acid activated bleaching earth with neutral pH, indicating that performance and adsorption capacities of bleaching earth are the predominant factors in the removal of esters, rather than its acidity profile. The combination of high dosage phosphoric acid during degumming with the use of acid activated bleaching earth eliminated almost all glycidyl esters during refining. Besides, the effects of crude palm oil quality was assessed and it was found that the quality of crude palm oil determines the level of formation of 3-MCPDE and glycidyl esters in palm oil during the high temperature deodorization step of physical refining process. Poor quality crude palm oil has strong impact towards 3-MCPDE and glycidyl esters formation due to the intrinsic components present within. The findings are useful to palm oil refining industry in choosing raw materials as an input during the refining process.

  7. Color recovery effect of different bleaching systems on a discolored composite resin.

    Gul, P; Harorlı, O T; Ocal, I B; Ergin, Z; Barutcigil, C

    2017-10-01

    Discoloration of resin-based composites is a commonly encountered problem, and bleaching agents may be used for the therapy of the existing discoloration. The purpose of this study was to investigate in vitro color recovery effect of different bleaching systems on the heavily discolored composite resin. Fifty disk-shaped dental composite specimens were prepared using A2 shade nanohybrid universal composite resin (3M ESPE Filtek Z550, St. Paul, MN, USA). Composite samples were immersed in coffee and turnip juice for 1 week in each. One laser activated bleaching (LB) (Biolase Laserwhite*20) and three conventional bleaching systems (Ultradent Opalescence Boost 40% (OB), Ultradent Opalescence PF 15% home bleaching (HB), Crest 3D White [Whitening Mouthwash]) were tested in this study. Distilled water was used as control group. The color of the samples were measured using a spectrophotometer (VITA Easy shade Compact, VITA Zahnfabrik, Bad Säckingen, Germany). Color changes (ΔE00) were calculated using the CIEDE2000 formula. Statistical analyses were conducted using paired samples test, one-way analysis of variance, and Tukey's multiple comparison tests (α = 0.05). The staining beverages caused perceptible discoloration (ΔE00 > 2.25). The color recovery effect of all bleaching systems was statistically determined to be more effective than the control group (P OB group was found as the most effective bleaching system, there was no statistically significant difference among HB, OB, and LB groups (P > 0.05). Within the limitation of this in vitro study, the highest recovery effect was determined in office bleaching system among all bleaching systems. However, home and laser bleaching systems were determined as effective as office bleaching system.

  8. Performance Enhancements to the Hanford Waste Treatment and Immobilization Plant Low-Activity Waste Vitrification System

    Hamel, W. F.; Gerdes, K.; Holton, L. K.; Pegg, I.L.; Bowan, B.W.

    2006-01-01

    The U.S Department of Energy Office of River Protection (DOE-ORP) is constructing a Waste Treatment and Immobilization Plant (WTP) for the treatment and vitrification of underground tank wastes stored at the Hanford Site in Washington State. The WTP comprises four major facilities: a pretreatment facility to separate the tank waste into high level waste (HLW) and low-activity waste (LAW) process streams, a HLW vitrification facility to immobilize the HLW fraction; a LAW vitrification facility to immobilize the LAW fraction, and an analytical laboratory to support the operations of all four treatment facilities. DOE has established strategic objectives to optimize the performance of the WTP facilities and the LAW and HLW waste forms to reduce the overall schedule and cost for treatment and vitrification of the Hanford tank wastes. This strategy has been implemented by establishing performance expectations in the WTP contract for the facilities and waste forms. In addition, DOE, as owner-operator of the WTP facilities, continues to evaluate 1) the design, to determine the potential for performance above the requirements specified in the WTP contract; and 2) improvements in production of the LAW and HLW waste forms. This paper reports recent progress directed at improving production of the LAW waste form. DOE's initial assessment, which is based on the work reported in this paper, is that the treatment rate of the WTP LAW vitrification facility can be increased by a factor of 2 to 4 with a combination of revised glass formulations, modest increases in melter glass operating temperatures, and a second-generation LAW melter with a larger surface area. Implementing these improvements in the LAW waste immobilization capability can benefit the LAW treatment mission by reducing the cost of waste treatment. (authors)

  9. Learning the ABCs: Activity based costing in waste operations

    Zocher, Marc A.

    1992-01-01

    The United States Department of Energy (DOE) is facing a challenging new national role based on current world events, changing public perception and awareness, and a legacy of wastes generated in the past. Clearly, the DOE must put mechanisms in place to comply with environmental rules, regulations, and good management practices so that public health risk is minimized while programmatic costs are controlled. DOE has begun this process and has developed a Five-Year Plan to describe the activities necessary to comply with both cleanup, or environmental restoration, and waste management of existing waste streams. The focus of this paper is how to best manage the treatment, storage, disposal, and transportation of waste throughout the DOE weapons complex by using Activity Based Costing (ABC) to both plan and control expenditures in DOE Waste Management (WM). The basics of ABC, along with an example, will be detailed. (author)

  10. R ampersand D activities at DOE applicable to mixed waste

    Erickson, M.D.; Devgun, J.S.; Brown, J.J.; Beskid, N.J.

    1991-01-01

    The Department of Energy (DOE) has established the Office of Environmental Restoration and Waste Management. Within the new organization, the Office of Technology Development (OTD) is responsible for research, development, demonstration, testing and evaluation (RDDT ampersand E) activities aimed at meeting DOE cleanup goals, while minimizing cost and risk. Because of US governmental activities dating back to the Manhattan project, mixed radioactive and hazardous waste is an area of particular concern to DOE. The OTD is responsible for a number of R ampersand D activities aimed at improving capabilities to characterize, control, and properly dispose of mixed waste. These activities and their progress to date will be reviewed. In addition, needs for additional R ampersand D on managing mixed waste will be presented. 5 refs., 2 tabs

  11. Anaerobic bioleaching of metals from waste activated sludge

    Meulepas, Roel J W; Gonzalez-Gil, Graciela; Teshager, Fitfety Melese; Witharana, Ayoma; Saikaly, Pascal; Lens, Piet Nl L

    2015-01-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether

  12. Study on Bleaching Technology of Cotton Fabric with Sodium Percarbonate

    Li Zhi; Wang Yanling; Wang Zhichao

    2016-01-01

    Bleach cotton fabric with sodium percarbonate solution. Analyse of the effect of the concentration of sodium percarbonate solution, bleaching time, bleaching temperature and the light radiation on the bleaching effect of fabric.The result shows that increasing concentrations of percarbonate,increasing the bleaching time , raising the bleaching temperature and the UV irradiation may whiten the cotton fabric.The most suitable conditions for the bleaching process is concentration of sodium perca...

  13. Characterization plan for the immobilized low-activity waste borehole

    Reidel, S.P.; Reynolds, K.D.

    1998-03-01

    The US Department of Energy's (DOE's) Hanford Site has the most diverse and largest amounts of radioactive tank waste in the US. High-level radioactive waste has been stored at Hanford in large underground tanks since 1944. Approximately 209,000 m 3 (54 Mgal) of waste are currently stored in 177 tanks. Vitrification and onsite disposal of low activity tank waste (LAW) are embodied in the strategy described in the Tri-Party Agreement. The tank waste is to be retrieved, separated into low- and high-level fractions, and then immobilized by private vendors. The DOE will receive the vitrified waste from private vendors and dispose of the low-activity fraction in the Hanford Site 200 East Area. The Immobilized Low-Activity Waste Disposal Complex (ILAWDC) is part of the disposal complex. This report is a plan to drill the first characterization borehole and collect data at the ILAWDC. This plan updates and revises the deep borehole portion of the characterization plan for the ILAWDC by Reidel and others (1995). It describes data collection activities for determining the physical and chemical properties of the vadose zone and the saturated zone at and in the immediate vicinity of the proposed ILAWDC. These properties then will be used to develop a conceptual geohydrologic model of the ILAWDC site in support of the Hanford ILAW Performance Assessment

  14. Low Activity Waste Feed Process Control Strategy

    STAEHR, T.W.

    2000-01-01

    The primary purpose of this document is to describe the overall process control strategy for monitoring and controlling the functions associated with the Phase 1B high-level waste feed delivery. This document provides the basis for process monitoring and control functions and requirements needed throughput the double-shell tank system during Phase 1 high-level waste feed delivery. This document is intended to be used by (1) the developers of the future Process Control Plan and (2) the developers of the monitoring and control system

  15. Reportable Nuclide Criteria for ORNL Radioactive Waste Management Activities - 13005

    McDowell, Kip; Forrester, Tim; Saunders, Mark

    2013-01-01

    The U.S. Department of Energy's Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee generates numerous radioactive waste streams. Many of those streams contain a large number of radionuclides with an extremely broad range of concentrations. To feasibly manage the radionuclide information, ORNL developed reportable nuclide criteria to distinguish between those nuclides in a waste stream that require waste tracking versus those nuclides of such minimal activity that do not require tracking. The criteria include tracking thresholds drawn from ORNL onsite management requirements, transportation requirements, and relevant treatment and disposal facility acceptance criteria. As a management practice, ORNL maintains waste tracking on a nuclide in a specific waste stream if it exceeds any of the reportable nuclide criteria. Nuclides in a specific waste stream that screen out as non-reportable under all these criteria may be dropped from ORNL waste tracking. The benefit of these criteria is to ensure that nuclides in a waste stream with activities which meaningfully affect safety and compliance are tracked, while documenting the basis for removing certain isotopes from further consideration. (authors)

  16. Leaching of gold from a mechanically and mechanochemically activated waste

    Jana Ficeriová

    2010-03-01

    Full Text Available The intensification of leaching of gold from a waste using mechanical activation (milling in water and mechanochemical activation(milling in thiourea solution were studied as the pretreatment steps. The leaching of “as-received“ sample in an acid thiourea solutionresulted in 78 % Au dissolution, after mechanical activation 98 % and mechanochemical activation up to 99 % of the gold was leachedduring 120 min. The mechanochemical activation resulted in an increase of the specific surface area of the waste from 0.6 m2g-1to a maximum value of 20.5 m2g-1. The activation was performed in an attritor using variable milling times. The physico-chemical changesin the waste as a consequence of mechanochemical activation had a pronounced influence on the subsequent gold extraction.

  17. The effects of coral bleaching on settlement preferences and growth of juvenile butterflyfishes.

    Cole, A J; Lawton, R J; Pisapia, C; Pratchett, M S

    2014-07-01

    Coral bleaching and associated mortality is an increasingly prominent threat to coral reef ecosystems. Although the effects of bleaching-induced coral mortality on reef fishes have been well demonstrated, corals can remain bleached for several weeks prior to recovery or death and little is known about how bleaching affects resident fishes during this time period. This study compared growth rates of two species of juvenile butterflyfishes (Chaetodon aureofasciatus and Chaetodon lunulatus) that were restricted to feeding upon either bleached or healthy coral tissue of Acropora spathulata or Pocillopora damicornis. Coral condition (bleached vs. unbleached) had no significant effects on changes in total length or weight over a 23-day period. Likewise, in a habitat choice experiment, juvenile butterflyfishes did not discriminate between healthy and bleached corals, but actively avoided using recently dead colonies. These results indicate that juvenile coral-feeding fishes are relatively robust to short term effects of bleaching events, provided that the corals do recover. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  18. Effect of different bleaching strategies on microhardness of a silorane-based composite resin.

    Bahari, Mahmoud; Savadi Oskoee, Siavash; Mohammadi, Narmin; Ebrahimi Chaharom, Mohammad Esmaeel; Godrati, Mostafa; Savadi Oskoee, Ayda

    2016-01-01

    Background. Dentists' awareness of the effects of bleaching agents on the surface and mechanical properties of restorative materials is of utmost importance. Therefore, this in vitro study was undertaken to investigate the effects of different bleaching strategies on the microhardness of a silorane-based composite resin. Methods. Eighty samples of a silorane-based composite resin (measuring 4 mm in diameter and 2 mm in thickness) were prepared within acrylic molds. The samples were polished and randomly assigned to 4 groups (n=20). Group 1 (controls) were stored in distilled water for 2 weeks. The samples in group 2 underwent a bleaching procedure with 15% carbamide peroxide for two weeks two hours daily. The samples in group 3 were bleached with 35% hydrogen peroxide twice 5 days apart for 30 minutes each time. The samples in group 4 underwent a bleaching procedure with light-activated 35% hydrogen peroxide under LED light once for 40 minutes. Then the microhardness of the samples was determined using Vickers method. Data were analyzed with one-way ANOVA and post hoc Tukey tests (P bleaching agents significantly decreased microhardness compared to the control group (P 0.05). Conclusion. Bleaching agents decreased microhardness of silorane-based composite resin restorations, the magnitude of which depending on the bleaching strategy used.

  19. Assessment of acute phase proteins and oxidative stress status of Nigerians using bleaching agents

    Akibinu, M.O.; Arinola, O.G.; Afolabi, K.A.

    2010-01-01

    The disruption of primary innate immune function of the epidermal layer of the skin accounts for the susceptibility of individuals using bleaching agents to localized or systemic infections. This subverted innate immunity in these people may lead to other pathological conditions. The resultant effects of skin bleaching and phagocytes activation in response to infections have not been studied in Nigerians using bleaching agents. The present study therefore assessed the levels of C-reactive protein (CRP), albumin, total antioxidant potential (TAP), total plasma peroxides (TPP), oxidative stress index (OSI) and malonaldehyde (MDA) in the users bleaching agents. Thirty (30) people who had used bleaching agents for average of 4.9 + 1.2 years participated in this study. They were recruited from various schools and markets within the city of Ibadan, Oyo State, Nigeria. Thirty apparently healthy staffs of University College Hospital Ibadan, Ibaadan, Nigeria, who had never used bleaching agents served as controls. All the subjects used for this study had no metabolic abnormality and tested negative to both HIV and hepatitis B infections. The mean value of TAP (p 0.20) when compared with the controls. Oxidative stress and chronic inflammation are possible consequences of skin bleaching. The users of skin bleaching agents may need antioxidant therapies to avert the risks of oxidative stress. (author)

  20. Application of TAED/H2O2 system for low temperature bleaching of crude cellulose extracted from jute fiber

    Wen, Zuoqiang; Zou, Linbo; Wang, Weiming

    2018-03-01

    Tetraacetylethylenediamine (TAED) activated hydrogen peroxide system had been applied for bleaching of crude cellulose extracted from jute fiber. Comparing with conventional hydrogen peroxide bleaching system, those results showed that bleaching temperature and time could be effectively reduced, and a preferable whiteness could be produced under faint alkaline condition. And the optimum conditions for activated bleaching system could be summarized as molar ratio of H2O2/TAED 1:0.7, pH 8, pure hydrogen peroxide 0.09 mol/L, temperature 70 °C and time 60min.

  1. Conversion of highly active waste to solids

    Scheffler, K.

    Borosilicate glasses were selected as matrix material for solidification of highly radioactive wastes. Current laboratory work on the VERA process is described. Goals were met by a five-component glass VG-38 and a glass-ceramic VC-15. The VERA process is described: flowsheet, denitration, calcinator, fusion facility

  2. Activity measurements at a waste volume reduction facility

    Richardson, J.; Lee, D.A.

    1979-01-01

    The monitoring program for Ontario Hydro's radioactive waste management site will be described, several aspects of which will be discussed in detail. The program at this facility includes categorization, volume reduction processing, and storage of solid radioactive wastes from nuclear generating stations of the CANDU type. At the present time, two types of volume reduction process are in operation - incineration and compaction. Following categorization and processing, wastes are stored in in-ground concrete trenches or tile-holes, or in above-ground quadricells. The monitoring program is divided into three areas: public safety, worker safety, and structural integrity. Development projects with respect to the monitoring program have been undertaken to achieve activity accounting for the total waste management program. In particular, a field measurement for the radioactivity content of radioactive ash containers and compacted waste drums

  3. Reuse of discarded deactivated bleaching earth in the bleaching of oils

    Girgis, Adel Y.

    2005-03-01

    Full Text Available Discarded bleaching earth was used after its reactivation for the bleaching of sunflower, soybean and corn oils. The efficiency of reactivated bleaching earth was compared to the efficiency of virgin activated bleaching earth. Acid reactivated earth (pH 2.5-3 had a slightly higher content in silicone than virgin activated or neutralized reactivated earths. The best results in the color of sunflower and corn oils were obtained when neutralized earth (pH 6–7 was used at 1 and 2 % levels. Acid reactivated earth used at 2 % achieved a higher reduction in soybean oil color than virgin earth (pH 3 at the same dosage. Both reactivated earths reduced peroxide value, iron, conjugated dienes and soap, while they increased acidity and conjugated trienes. Furthermore, these reactivated earths determined higher decrements in the oil induction period than virgin earth. Reactivated earth could be used for 5 cycles for the bleaching of soybean or corn oils and for more than 6 cycles for sunflower oil.Tierra decolorante desechada, fue empleada, tras su reactivación para decolorar aceites de girasol, soja y maíz. La eficiencia de la tierra decolorante reactivada fue comparada con la de la virgen activada. La tierra reactivada ácida (pH 2,5–3 tuvo ligeramente mayor contenido en silicona que la tierra virgen o la reactivada neutra. Los mejores resultados en el color de los aceites de girasol y maíz fueron obtenidos cuando se emplearon niveles del 1 y 2 % de tierra reactivada neutra (pH 6-7. La tierra ácida reactivada, usada al 2 % consiguió una mayor reducción del color del aceite de soja, que una misma dosis de tierra virgen (pH 3. Ambas tierras reactivadas redujeron el índice de peróxidos, hierro, dienos conjugados y jabón de los aceites, mientras que hicieron aumentar la acidez y los trienos conjugados. Además, estas tierras reactivadas determinaron mayores descensos en los periodos de inducción del aceite que la tierra virgen. Las tierras

  4. Body image disturbance and skin bleaching.

    Charles, Christopher A D; McLean, Shua-Kym

    2017-11-01

    This study looks at body image disturbance among Jamaicans who bleach their skin. The hypothesis states that there is a positive relationship between skin bleaching and body image disturbance. The study used a convenience sample of 160 participants with a skin bleaching group (n = 80) and a non-bleaching comparison group (n = 80). The instrument included demographic questions, the body image disturbance questionnaire (BIDQ), and questions about skin bleaching. The results of a t-test revealed that the skin bleaching group (M = 1.5255, SD = 0.42169) was not significantly different from the non-bleaching group (M = 1.4938, SD = 0.74217) in terms of body image disturbance, t(158) = 0.333, p = .740. The participants who bleached did not suffer from body image disturbance. Self-reports revealed that they bleached to acquire beauty, attract a partner, elude the police, and market skin bleaching products. The practice was fashionable and popular and it made some participants feel good, while others were fans of a popular musical artiste who bleached his skin. The majority of participants bleached because of the perceived personal, social, and entrepreneurial benefits of the practice and not because they suffered emotional distress, anxiety, and functional impairment because of their skin colour. However, there was some level of BID among the minority of participants who argued that they bleached because they wanted to be pretty so they were emotionally distressed about there body image and experienced functional impairment. © 2017 The British Psychological Society.

  5. Treatment of low alpha activity liquid wastes

    Nannicini, R.; Fenoglio, F.; Pozzi, L.

    1984-01-01

    The nuclear industry considers so big safety problems that the purifying treatment of liquid wastes must always provide for a complete recycle of the liquid strems from the production processes as regard this problem. ''Enea-Comb-Ifec'' people from saluggia, already previously engages with verifying and setting-up ''Sol-Gel'' process for the recover of uranium-plutonium solutions coming from irradiated fuel reprocessing, started an experimental work, with the assistance of ''Cnr-Irsa'' from Rome, on the applicability of the biological treatment to the purification of liquid wastes coming from the production process itself. The present technical report gives, besides a short description of the ''Sol-Gel'' process, the first results, only relating to the biological stage of the whole proposed purifyng treatment, included the final results of the experimental work, object of a contract between ''Enea-Ifec'' and ''Snam progetti'' from Fano

  6. Microhardness of demineralized enamel following home bleaching and laser-assisted in office bleaching

    Ghanbarzadeh, Majid; Akbari, Majid; Hamzei, Haniye

    2015-01-01

    Background There is little data regarding the effect of tooth whitening on microhardness of white spot lesions. This study was conducted to investigate the effect of home-bleaching and laser-assisted in-office bleaching on microhardness of demineralized enamel. Material and Methods Forty bovine incisors were selected and immersed in a demineralizing solution for 12 weeks to induce white spot lesions. Enamel blocks were prepared and randomly assigned to two groups of 20 each. The first group underwent home bleaching with 15% carbamide peroxide which was applied for 8 hours a day over a period of 15 days. In the second group, in-office bleaching was performed by 40% hydrogen peroxide and powered by irradiation from an 810 nm gallium-aluminum-arsenide (GaAlAs) diode laser (CW, 2W). This process was performed for 3 sessions every seven days, in 15 days. The specimens were stored in Fusayama Meyer artificial saliva during the experiment. Surface microhardness was assessed before and after the bleaching therapies in both groups. Results Microhardness decreased significantly following both home bleaching and laser-assisted in-office bleaching (pTooth whitening through home bleaching or laser-assisted in-office bleaching can result in a significant reduction in microhardness of white spot lesions. Therefore, it is suggested to take protective measures on bleached demineralized enamel. Key words:White spot lesion, bleaching, laser, microhardness, demineralized enamel, home bleaching, in-office bleaching. PMID:26330939

  7. Segregation of low-level dry active waste

    Kornblith, L. Jr.; Naughton, M.D.; Welsh, L.

    1984-01-01

    A program has been carried out to characterize the Dry Active Waste (DAW) stream from a typical PWR power plant in order to determine the usefulness of large-volume DAW monitors for segregating such waste in order to dispose of it in appropriate facilities. A waste monitor using plastic scintillation counters was used for measuring the waste. The monitor had a volume of about 300 liters and an overall efficiency of about 12% for a typical fission product mixture. It provides automatic compensation for background radioactivity and can measure a bag of waste in less than a minute, including background measurements. Six hundred consecutively generated bags of DAW were measured. These had a total activity of about one millicurie and an average specific activity of about 540 nanocuries per kilogram. About half of the bags contained less than 1000 nanocuries and had specific activities of less than 100 nanocuries per kilogram. Based on simplified preliminary calculations, it appears that an evaluation of the risks of disposal of bags such as these in a landfill other than a low-level waste disposal facility could be carried out that would demonstrate that such disposal of half or more of these bags would not result in any substantial hazard, either short or long term

  8. Storage drums for radio-active waste

    Knights, H.C.

    1982-01-01

    The lid of a storage drum for radioactive waste is secured by a series of clamps each of which has a hook for engaging the rim of the drum. Each clamp has an indicating means whereby a remote operator can check that the lid is secured to the drum. In a second embodiment, the position of an arm acts as a visual indication as to whether or not the clamp is in engagement with the container rim. (author)

  9. Kinetics and thermodynamics of aqueous Cu(II adsorption on heat regenerated spent bleaching earth

    Enos W. Wambu

    2011-08-01

    Full Text Available This study investigated the kinetics and thermodynamics of copper(II removal from aqueous solutions using spent bleaching earth (SBE. The spent bleaching earth, a waste material from edible oil processing industries, was reactivated by heat treatment at 370 oC after residual oil extraction in excess methyl-ethyl ketone. Copper adsorption tests were carried out at room temperature (22±3 oC using 5.4 x 10-3C M metal concentrations. More than 70% metal removal was recorded in the first four hours although adsorption continued to rise to within 90% at 42 hours. The pH, adsorbent dosage and initial concentrations were master variables affecting RSBE adsorption of Cu(II ions. The adsorption equilibrium was adequately described by the Dubinin-Radushkevich (D-R and the Temkin isotherms and the maximum sorption capacity derived from the D-R isotherm was compared with those of some other low cost adsorbents. The adsorption process was found to follow Lagergren Pseudo-second order kinetics complimented by intra-particle diffusion kinetics at prolonged periods of equilibration. Based on the D-R isotherm adsorption energy and the thermodynamic adsorption free energy ∆G, it was suggested that the process is spontaneous and based on electrostatic interactions between the metal ions and exposed active sites in the adsorbent surface.

  10. Phase 1 immobilized low-activity waste operational source term

    Burbank, D.A.

    1998-01-01

    This report presents an engineering analysis of the Phase 1 privatization feeds to establish an operational source term for storage and disposal of immobilized low-activity waste packages at the Hanford Site. The source term information is needed to establish a preliminary estimate of the numbers of remote-handled and contact-handled waste packages. A discussion of the uncertainties and their impact on the source term and waste package distribution is also presented. It should be noted that this study is concerned with operational impacts only. Source terms used for accident scenarios would differ due to alpha and beta radiation which were not significant in this study

  11. Incineration plant for low active waste at Inshass, LAWI

    Krug, W.; Thoene, L.; Schmitz, H.J.; Abdelrazek, I.D.

    1993-10-01

    The LAWI (Low Active Waste Incinerator) prototype incinerating plant was devised and constructed according to the principle of the Juelich thermoprocess and installed at the Egyptian research centre Inshass. In parallel, AEA Cairo devised and constructed their own operations building for this plant with all the features, infrastructural installations and rooms required for operating the plant and handling and treating low-level radioactive wastes. The dimensions of this incinerator were selected so as to be sufficient for the disposal of solid, weakly radioactive combustible wastes from the Inshass Research Centre and the environment (e.g. Cairo hospitals). (orig./DG) [de

  12. In vitro colorimetric evaluation of the efficacy of home bleaching and over-the-counter bleaching products.

    Dietschi, Didier; Benbachir, Nacer; Krejci, Ivo

    2010-06-01

    Various bleaching modalities are now offered to patients, either monitored by the dental office or self-directed, for which relative efficiency is unknown. The aim of this in vitro study was to evaluate the ability of bleaching products and protocols to lighten enamel and dentin. Bovine tooth specimens of standardized thickness (2.5 +/- 0.025 mm with similar dentin and enamel thickness) were prepared and stained with whole blood and hemolysate before being submitted to seven supervised or self-directed bleaching regimens: tray-based bleaching using 10% (Opalescence, Ultradent; Nite White, Discus Dental) or light-activated 30% (Metatray, Metatray) carbamide peroxide (CP); 6% (Zoom, Discus Dental) or 9% (TresWhite, Ultradent) hydrogen peroxide (HP); strips (Whitening Strips, Oral B-Rembrandt); and paint-on gel (Paint on Plus, Ivoclar Vivadent) containing 8.1% and 6% HP, respectively. Colorimetric measurements were performed on each specimen side, according to the CIE L*a*b* system, before and after staining, as well as after 5, 10, and the recommended number of bleaching applications. Color change after recommended number of applications (DEr) varied from 15.72 (Metatray) to 29.67 (Nite White) at enamel and 14.91 (Paint on Plus) to 41.43 (Nite White) at dentin side; Nite White (10% CP) and TresWhite (9% HP) were more effective than Metatray (30% CP) and Paint on Plus (6% HP) after 5 or the recommended number of applications. In this in vitro study based on bovine teeth, tray-based systems produced the faster and better bleaching effect, regardless of the product and concentration used, at both enamel and dentin sides.

  13. Desactivation of liquid radioactive wastes of low and medium activity

    Golinski, M.; Charomska, K.

    1978-01-01

    The results of research made according to the prodranm of scientific and technical cooperation of the CMEA countries are discussed. The main direction of these research works is on future improvement of installations for purification of liquid radioactive wastes by chemical methods of coprecipitation and coagulation, ion exchange, sorption, distillation and electrolysis. It was shown that methods of coprecipitation and coagulation have low efficiency and the activity reduction factor seldom was more than 10. In sorption processes different sorbents, both organic and nonorganic were used. The modified bentonite used as a sorbent agent has shown high selectivity towards zesium ions. Waste concentration by means of distillation is an universal but rather expensive method and is applied mainly in the cases of high salts concentration and high specific activity of liquid wastes. Electrolysis, as a method of the liquid wastes purification is used in the USSR and has high efficiency with low energy consumption. (I.T.) [ru

  14. Influence of dental bleaching on marginal leakage of Class V restorations

    Andréia Cristina Ramos Dorini

    2010-04-01

    Full Text Available Objective: Evaluate the in vitro effect of bleaching performed in the dental office and waiting time on the degree of microleakage in class V cavities with margins in enamel, restored with resin composite. Methods: Forty-five human third molars were used, in which the vestibular faces were bleached with 35% hydrogen peroxide activated with LED and the palatine faces were not bleached (control. The teeth were randomly divided into 3 groups with 15 teeth in each: Group 1, restored immediately after bleaching; Group 2, seven days after bleaching; and Group 3, fourteen days after bleaching. After cavity preparation, 35% phosphoric acid, Adper Single Bond 2 adhesive (3M ESPE, St. Paul, Mn, USA, and resin composite Filtek Z250 (3M ESPE, St. Paul, MN, USA were applied. The teeth were thermal cycled and sealed with red nail polish on the bleached faces and blue on the non bleached faces, except for 1mm around the restored region. The samples were classified according to the following scores: 0 = no leakage, 1 = minimum leakage (less than 1 / 3 the length of the wall, 2 = moderate leakage (1/3 to 2/3 of the wall and 3 = extensive leakage (over 2/3 of the wall. The data were submitted to the Kruskal-Wallis test at a level of significance of 5%. Results: The restorative procedure immediately after bleaching resulted in statistically higher microleakage values (p 0.05. Conclusion: Based on the results, it is advisable to wait at least 7 days after bleaching to make the definitive restoration.

  15. Non-bleached colonies of massive Porites may attract fishes for selective grazing during mass bleaching events

    Eri Ikeuchi

    2017-06-01

    Full Text Available In this study we investigated the variation in grazing scar densities between bleached and non-bleached colonies of massive Porites species in Sekisei Lagoon (Okinawa, southwestern Japan during a mass bleaching event in 2016. The grazing scar densities and bleaching susceptibility varied among neighboring colonies of massive Porites spp. However, non-bleached colonies had significantly more surface scars than bleached colonies. One explanation for these variations is that corallivorous fishes may selectively graze on non-bleached, thermally tolerant colonies. This is the first report of a relationship between grazing scars and the bleaching status of massive Porites spp. colonies during a mass bleaching event.

  16. Multifocal ERG reveals long distance effects of a local bleach in the retina.

    Kretschmann, U; Tornow, R P; Zrenner, E

    1998-06-01

    To examine the distribution of ERG-activity in the central visual field after local bleaching of the fovea, multifocal electroretinograms were recorded in eight normal volunteers before, during and after recurrent light exposure. During bleaching (90% bleached pigment), the response density (scalar product) of the foveal area (0-2 degrees eccentricity) decreased from 10.7 +/- 3.5 to 4.1 +/- 1.9 nV/degree2 (P < 0.001). The average activity in the extrafoveal macular area was unchanged, while the amplitudes were frequently (in 53 of 54 areas) enhanced at 5-30.5 degrees eccentricity. Here the average response density changed from 3.1 +/- 0.9 to 3.5 +/- 1.0 nV/degree2 (P < 0.001). A fast recovery of foveal responses after cessation of bleaching occurred. Besides a strong decrease of response in the directly bleached area, local bleaching led to enhanced activity mainly 3-27 degrees distant from the bleached area.

  17. Incineration of alpha-active solid waste by microwaves

    Mallik, G K; Bhargava, V K; Kamath, H S; Purushotham, D S.C. [Bhabha Atomic Research Centre, Tarapur (India). Advanced Fuel Fabrication Facility

    1996-12-31

    The conventional techniques for treatment of alpha-active compressible solid waste involve incineration using electrically heated incinerators and subsequent recovery of special nuclear materials (SNM) from the ash by acid leaching. A microwave incineration followed by microwave digestion and SNM recovery from ash has specific advantages from maintenance and productivity consideration. The paper describes a preliminary work carried out with simulated uranium containing compressible solid waste using microwave heating technique. (author). 3 refs., 1 tab.

  18. Characterization of silicoaluminates for low and medium activity wastes packaging

    Rivoallan, A.; Berson, X.

    1996-01-01

    Studies are done in order to demonstrate many advantages (as an important volume reduction and a greater chemical stability) of packaging low and medium activity wastes in crystal structures compared with concrete and bitumen. In order to understand the consequences of hazardous chemical composition (especially anions) in the waste on the characteristics of the mineral packaging, a simulation study is developed with inactive concentrates. It leads to well crystallized structures which have not the same major crystallized phase. (authors)

  19. Effect of ultrasonic specific energy on waste activated sludge ...

    The effect of ultrasonic specific energy on waste activated sludge (WAS) solubilization and enzyme activity was investigated in this study. Experimental results showed that the increase of ultrasonic specific energy in the range of 0 - 90000 kJ/kg dried sludge (DS) benefited WAS particle size reduction and the solubilization ...

  20. Differential gene expression during thermal stress and bleaching in the Caribbean coral Montastraea faveolata.

    DeSalvo, M K; Voolstra, C R; Sunagawa, S; Schwarz, J A; Stillman, J H; Coffroth, M A; Szmant, A M; Medina, M

    2008-09-01

    The declining health of coral reefs worldwide is likely to intensify in response to continued anthropogenic disturbance from coastal development, pollution, and climate change. In response to these stresses, reef-building corals may exhibit bleaching, which marks the breakdown in symbiosis between coral and zooxanthellae. Mass coral bleaching due to elevated water temperature can devastate coral reefs on a large geographical scale. In order to understand the molecular and cellular basis of bleaching in corals, we have measured gene expression changes associated with thermal stress and bleaching using a complementary DNA microarray containing 1310 genes of the Caribbean coral Montastraea faveolata. In a first experiment, we identified differentially expressed genes by comparing experimentally bleached M. faveolata fragments to control non-heat-stressed fragments. In a second experiment, we identified differentially expressed genes during a time course experiment with four time points across 9 days. Results suggest that thermal stress and bleaching in M. faveolata affect the following processes: oxidative stress, Ca(2+) homeostasis, cytoskeletal organization, cell death, calcification, metabolism, protein synthesis, heat shock protein activity, and transposon activity. These results represent the first medium-scale transcriptomic study focused on revealing the cellular foundation of thermal stress-induced coral bleaching. We postulate that oxidative stress in thermal-stressed corals causes a disruption of Ca(2+) homeostasis, which in turn leads to cytoskeletal and cell adhesion changes, decreased calcification, and the initiation of cell death via apoptosis and necrosis.

  1. Modelling the thermal bleaching of OSL signal in the case of a competition between recombination centres

    Chruscinska, A.

    2009-01-01

    The thermal bleaching of the optically stimulated luminescence (OSL) has been investigated by computer simulations for a model including three traps and two luminescence centres. The deepest trap is active only during the OSL process. Two other traps are active only during the thermal bleaching. The thermal bleaching effects on the OSL intensity as well as on the OSL curve shape are presented for the wide range of trap and luminescence centre parameters and for the different settings of optical detection window. The conventional OSL curve analysis consisting in decomposition of the OSL curve into first order components is applied to the simulation results and the optical cross section spectra obtained as a result of this analysis are compared with the model assumptions. The simulations show that OSL signal can decrease to undetectable level even when the traps related to this signal are not emptied during thermal bleaching. The residual level of the OSL signal after bleaching process, however, depends strongly on centre parameters and concentrations. The modifications of optical detection spectral window lead to significant changes of bleaching effects. The thermal bleaching influences also the optical cross section spectra obtained as a result of the OSL curve decomposition.

  2. Active Waste Materials Corrosion and Decontamination Tests

    Danielson, M.J.; Elmore, M.R.; Pitman, S.G.

    2000-01-01

    Stainless steel alloys, 304L and 316L, were corrosion tested in representative radioactive samples of three actual Hanford tank waste solutions (Tanks AW-101, C-104, AN-107). Both the 304L and 316L exhibited good corrosion performance when immersed in boiling waste solutions. The maximum general corrosion rate was 0.015 mm/y (0.60 mils per year). Generally, the 304L had a slightly higher rate than the 316L. No localized attack was observed after 122 days of testing in the liquid phase, liquid/vapor phase, or vapor phase. Radioactive plate-out decontamination tests indicated that a 24-hour exposure to 1 und M HNO 3 could remove about 99% of the radioactive components in the metal film when exposed to the C-104 and AN-107 solutions. The decontamination results are less certain for the AW-101 solution, since the initial contamination readings exceeded the capacity of the meter used for this test

  3. Efficacy of cold light bleaching using different bleaching times and their effects on human enamel.

    Wang, Wei; Zhu, Yuhe; Li, Jiajia; Liao, Susan; Ai, Hongjun

    2013-01-01

    This study investigated the efficacy of cold light bleaching using different bleaching times and the effects thereof on tooth enamel. Before and after bleaching, stained tooth specimens were subjected to visual and instrumental colorimetric assessments using Vita Shade Guide and spectrophotometric shade matching. Enamel surface alterations were examined using scanning electron microscopy (SEM) to analyze surface morphology, surface microhardness (SMH) measurement to determine changes in mechanical properties, and X-ray diffraction (XRD) to characterize post-bleaching enamel composition. Cold light bleaching successfully improved tooth color, with optimal efficacy when bleaching time was beyond 10 min. Significant differences in surface morphology were observed among the different bleaching times, but no significant differences were observed for enamel composition and surface microhardness among the different bleaching times. Results of this study revealed an association between the bleaching time of cold light bleaching and its whitening efficacy. Together with the results on enamel surface changes, this study provided positive evidence to support cold light bleaching as an in-office bleaching treatment.

  4. Activation analyses updating the ITER radioactive waste assessment

    Pampin, R.; Zheng, S.; Lilley, S.; Na, B.C.; Loughlin, M.J.; Taylor, N.P.

    2012-01-01

    Highlights: ► Comprehensive updated of ITER radwaste assessment. ► Latest coupled neutronics and activation methods. ► Type A waste at shutdown decays to TFA within 100 years. ► Most type B waste at shutdown is still type B after 100 years. - Abstract: A study is reported which computes the radiation transport and activation response throughout the ITER machine and updates the ITER radioactive waste assessment using modern 3D models and up-to-date methods. The latest information on component design, maintenance, replacement schedules and materials is adopted. The radwaste classification is revised for all the major components of ITER, as well as several representative port plugs. Results include categorisation snapshots at different decay times, time histories of radiological quantities throughout the machine, and guidelines on interim decay times for components. All plasma-facing materials except tungsten are found to classify as type B due to the transmutation of their main constituents. Major contributors to the IRAS index of all materials are reported. Elemental concentration limits for type A classification of first wall and divertor materials are obtained; for the steels, only a reduction in service lifetime can reduce the waste class. Comparison of total waste amounts with earlier assessments is limited by the fact that analyses of some components are still preliminary; the trend, however, indicates a potential reduction in the total amount of waste if component segregation is demonstrated.

  5. Hanford immobilized low-activity tank waste performance assessment

    Mann, F.M.

    1998-01-01

    The Hanford Immobilized Low-Activity Tank Waste Performance Assessment examines the long-term environmental and human health effects associated with the planned disposal of the vitrified low-level fraction of waste presently contained in Hanford Site tanks. The tank waste is the by-product of separating special nuclear materials from irradiated nuclear fuels over the past 50 years. This waste has been stored in underground single and double-shell tanks. The tank waste is to be retrieved, separated into low and high-activity fractions, and then immobilized by private vendors. The US Department of Energy (DOE) will receive the vitrified waste from private vendors and plans to dispose of the low-activity fraction in the Hanford Site 200 East Area. The high-level fraction will be stored at Hanford until a national repository is approved. This report provides the site-specific long-term environmental information needed by the DOE to issue a Disposal Authorization Statement that would allow the modification of the four existing concrete disposal vaults to provide better access for emplacement of the immobilized low-activity waste (ILAW) containers; filling of the modified vaults with the approximately 5,000 ILAW containers and filler material with the intent to dispose of the containers; construction of the first set of next-generation disposal facilities. The performance assessment activity will continue beyond this assessment. The activity will collect additional data on the geotechnical features of the disposal sites, the disposal facility design and construction, and the long-term performance of the waste. Better estimates of long-term performance will be produced and reviewed on a regular basis. Performance assessments supporting closure of filled facilities will be issued seeking approval of those actions necessary to conclude active disposal facility operations. This report also analyzes the long-term performance of the currently planned disposal system as a basis

  6. Hanford immobilized low-activity tank waste performance assessment

    Mann, F.M.

    1998-03-26

    The Hanford Immobilized Low-Activity Tank Waste Performance Assessment examines the long-term environmental and human health effects associated with the planned disposal of the vitrified low-level fraction of waste presently contained in Hanford Site tanks. The tank waste is the by-product of separating special nuclear materials from irradiated nuclear fuels over the past 50 years. This waste has been stored in underground single and double-shell tanks. The tank waste is to be retrieved, separated into low and high-activity fractions, and then immobilized by private vendors. The US Department of Energy (DOE) will receive the vitrified waste from private vendors and plans to dispose of the low-activity fraction in the Hanford Site 200 East Area. The high-level fraction will be stored at Hanford until a national repository is approved. This report provides the site-specific long-term environmental information needed by the DOE to issue a Disposal Authorization Statement that would allow the modification of the four existing concrete disposal vaults to provide better access for emplacement of the immobilized low-activity waste (ILAW) containers; filling of the modified vaults with the approximately 5,000 ILAW containers and filler material with the intent to dispose of the containers; construction of the first set of next-generation disposal facilities. The performance assessment activity will continue beyond this assessment. The activity will collect additional data on the geotechnical features of the disposal sites, the disposal facility design and construction, and the long-term performance of the waste. Better estimates of long-term performance will be produced and reviewed on a regular basis. Performance assessments supporting closure of filled facilities will be issued seeking approval of those actions necessary to conclude active disposal facility operations. This report also analyzes the long-term performance of the currently planned disposal system as a basis

  7. 1993 annual report of hazardous waste activities for the Oak Ridge K-25 site

    1994-02-01

    This report is a detailed listing of all of the Hazardous Waste activities occurring at Martin Marietta`s K-25 site. Contained herein are hazardous waste notification forms, waste stream reports, generator fee forms and various TSDR reports.

  8. 1993 annual report of hazardous waste activities for the Oak Ridge K-25 site

    1994-02-01

    This report is a detailed listing of all of the Hazardous Waste activities occurring at Martin Marietta's K-25 site. Contained herein are hazardous waste notification forms, waste stream reports, generator fee forms and various TSDR reports

  9. Distinguishing method for contamination/radio-activation of radioactive wastes

    Fukazawa, Takuji; Kato, Keiichiro; Koda, Satoshi.

    1994-01-01

    The present invention concerns a method of distinguishing the contamination/radio-activation of radioactive wastes used in processing wastes generated upon dismantling of exhausted nuclear reactors. Especially, contaminated/radio-activation is distinguished for wastes having openings such as pipes and valves, by utilizing scattering of γ-rays or γ-ray to β-ray ratio. That is, ratio of scattered γ-rays and direct γ-rays or ratio of β-rays and γ-rays from radioactive wastes are measured and compared by a radiation detector, to distinguish whether the radioactive wastes contaminated materials or radio-activated materials. For example, when an object to be measured having an opening is contaminated at the inner side, the radiation detector facing to the opening mainly detects high direct γ-rays emitted from the object to be measured while a radiation detector not facing the opening mainly detects high scattered γ-rays relatively. On the other hand, when the object is a radio-activated material, any of the detectors detect scattered γ-rays, so that they can be distinguished by these ratios. (I.S.)

  10. Transportation research activities in support of nuclear waste management programs

    Allen, G.C. Jr.; Cashwell, J.W.; Jefferson, R.M.

    1983-01-01

    Transportation Technology Center has been conducting a wide range of technical research activities to assure the ability to transport radioactive materials in a safe, reliable manner. These activities include tasks in basic, analysis methodology and system research areas. Recently, the requirements of defense waste shipments have served as a focal point for development tasks with the expectation that they would serve as a precursor for commercial activities. The passage of the Nuclear Waste Policy Act has placed additional responsibility on the Department of Energy for concerns involving the shipments of civilian materials. The development of additional research responsibilities is expected to proceed concurrently with the evolution of the transportation mission plan for civilian spent fuel and high-level wastes

  11. Transportation research activities in support of nuclear waste management programs

    Allen, G.C.; Luna, R.E.; Jefferson, R.M.; Wowak, W.E.

    1983-01-01

    The Transportation Technology Center has been conducting a wide range of technical and non-technical research activities to assure the ability to transport radioactive materials in a safe, reliable, and publicly acceptable manner. These activities include tasks in Information and Intergovernmental issues, Safety Assessment and Environmental Analysis and Technology Development. Until recently, the requirements of defense waste shipments have served as a focal point for development tasks with the expectation that they would serve as a precursor for commercial activities. The passage of the Nuclear Waste Policy Act has placed additional responsibility on DOE for concerns involving the shipments of civilian materials. The development of additional research responsibilities is expected to proceed concurrently with the evolution of the transportation mission plan for civilian spent fuel and high-level wastes

  12. 226Ra adsorption on active coals from waste waters

    Panturu, E.; Georgescu, D.P.; Serban, N.; Filip, D.; Radulescu, R.

    2000-01-01

    During the mining and extraction of uranium, the principle means of protection measurement is to prevent uranium and its products diffusing into the environment. The main carriers of radioactive elements in the environment are air and water. Therefore, reduction of the pollution at a uranium mine can be achieved by the treatment of waste waters contaminated with 226 Ra Radium contaminated waste waters represent a major biological risk. This paper presents the results of the study of the sorption of 226 Ra on active coal mechanisme and the influence of the physical and chemical characteristics of fluid. The 226 Ra removal from the residue pond water at the uranium ore processing plant was studied using eight types of indigenous active coals. The experimental results for each type of active coal and their effect on removal of 226 Ra from waste waters are presented in this paper. (author)

  13. Investigation of bleaching kinetics of the photochromic halogen-copper-cadmium glass

    Marczuk, K.; Ziemba, B.

    1997-01-01

    The curves of the isothermal glass bleaching kinetics of various conditions of exciting radiation are presented. Different values of radiation power, time of irradiation and temperature of samples were applied. analysis of the relaxation curves made it possible to distinguish three exponential components of the bleaching process with different time constants. For each component the relaxation coefficient has been determined. Basing on temperature dependence of the relaxation coefficients for the isothermal glass bleaching the activation energy for slow (E D = 0.46 eV) and fast (E K = 0.13 eV) colour centre decay process have been determined. (author)

  14. Biochemical methane potential of kraft bleaching effluent and codigestion with other in-mill streams

    Fitamo, Temesgen Mathewos; Dahl, Olli; Master, Emma

    2016-01-01

    and in combination: total bleaching effluent, alkaline bleaching effluent, kraft evaporator condensate, and chemithermomechanical pulping effluent. The total bleaching effluent, consisting of the chlorine dioxide bleaching and alkaline bleaching effluents, exhibited the highest potential for organic matter...

  15. Analysis of alternatives for immobilized low activity waste disposal

    Burbank, D.A.

    1997-10-28

    This report presents a study of alternative disposal system architectures and implementation strategies to provide onsite near-surface disposal capacity to receive the immobilized low-activity waste produced by the private vendors. The analysis shows that a flexible unit strategy that provides a suite of design solutions tailored to the characteristics of the immobilized low-activity waste will provide a disposal system that best meets the program goals of reducing the environmental, health, and safety impacts; meeting the schedule milestones; and minimizing the life-cycle cost of the program.

  16. Analysis of alternatives for immobilized low-activity waste disposal

    Burbank, D.A.

    1997-01-01

    This report presents a study of alternative disposal system architectures and implementation strategies to provide onsite near-surface disposal capacity to receive the immobilized low-activity waste produced by the private vendors. The analysis shows that a flexible unit strategy that provides a suite of design solutions tailored to the characteristics of the immobilized low-activity waste will provide a disposal system that best meets the program goals of reducing the environmental, health, and safety impacts; meeting the schedule milestones; and minimizing the life-cycle cost of the program

  17. Tropical cyclone cooling combats region-wide coral bleaching.

    Carrigan, Adam D; Puotinen, Marji

    2014-05-01

    Coral bleaching has become more frequent and widespread as a result of rising sea surface temperature (SST). During a regional scale SST anomaly, reef exposure to thermal stress is patchy in part due to physical factors that reduce SST to provide thermal refuge. Tropical cyclones (TCs - hurricanes, typhoons) can induce temperature drops at spatial scales comparable to that of the SST anomaly itself. Such cyclone cooling can mitigate bleaching across broad areas when well-timed and appropriately located, yet the spatial and temporal prevalence of this phenomenon has not been quantified. Here, satellite SST and historical TC data are used to reconstruct cool wakes (n=46) across the Caribbean during two active TC seasons (2005 and 2010) where high thermal stress was widespread. Upon comparison of these datasets with thermal stress data from Coral Reef Watch and published accounts of bleaching, it is evident that TC cooling reduced thermal stress at a region-wide scale. The results show that during a mass bleaching event, TC cooling reduced thermal stress below critical levels to potentially mitigate bleaching at some reefs, and interrupted natural warming cycles to slow the build-up of thermal stress at others. Furthermore, reconstructed TC wave damage zones suggest that it was rare for more reef area to be damaged by waves than was cooled (only 12% of TCs). Extending the time series back to 1985 (n = 314), we estimate that for the recent period of enhanced TC activity (1995-2010), the annual probability that cooling and thermal stress co-occur is as high as 31% at some reefs. Quantifying such probabilities across the other tropical regions where both coral reefs and TCs exist is vital for improving our understanding of how reef exposure to rising SSTs may vary, and contributes to a basis for targeting reef conservation. © 2014 John Wiley & Sons Ltd.

  18. In vitro penetration of bleaching agents into the pulp chamber

    Benetti, Ana Raquel; Valera, M C; Mancini, M N G

    2004-01-01

    To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures.......To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures....

  19. Activation of waste brewer's yeast Saccharomyces cerevisiae for bread production

    Popov Stevan D.

    2005-01-01

    Full Text Available The waste brewer's yeast S. cerevisiae (activated and non-activated was compared with the commercial baker's yeast regarding the volume of developed gas in dough, volume and freshness stability of produced bread. The activation of waste brewer's yeast resulted in the increased volume of developed gas in dough by 100% compared to non-activated brewer's yeast, and the obtained bread is of more stable freshness compared to bread produced with baker's yeast. The activation of BY affects positively the quality of produced bread regarding bread volume. The volume of developed gas in dough prepared with the use of non-activated BY was not sufficient, therefore, it should not be used as fermentation agent, but only as an additive in bread production process for bread freshness preservation. Intense mixing of dough results in more compressible crumb 48 hrs after baking compared to high-speed mixing.

  20. Characterization and application of municipal solid waste incineration (MSWI) bottom ash and waste granite powder in alkali activated slag

    Gao, X.; Yuan, B.; Yu, Q. L.; Brouwers, H. J.H.

    2017-01-01

    In this paper, the feasibility of using two solid wastes in alkali activated slag composites as construction and building materials is evaluated. One waste is the municipal solid waste incineration (MSWI) bottom ash, and the other one is fine granite powder from aggregate manufacturing. These two

  1. Inhibition of photosynthetic CO₂ fixation in the coral Pocillopora damicornis and its relationship to thermal bleaching.

    Hill, Ross; Szabó, Milán; ur Rehman, Ateeq; Vass, Imre; Ralph, Peter J; Larkum, Anthony W D

    2014-06-15

    Two inhibitors of the Calvin-Benson cycle [glycolaldehyde (GA) and potassium cyanide (KCN)] were used in cultured Symbiodinium cells and in nubbins of the coral Pocillopora damicornis to test the hypothesis that inhibition of the Calvin-Benson cycle triggers coral bleaching. Inhibitor concentration range-finding trials aimed to determine the appropriate concentration to generate inhibition of the Calvin-Benson cycle, but avoid other metabolic impacts to the symbiont and the animal host. Both 3 mmol l(-1) GA and 20 μmol l(-1) KCN caused minimal inhibition of host respiration, but did induce photosynthetic impairment, measured by a loss of photosystem II function and oxygen production. GA did not affect the severity of bleaching, nor induce bleaching in the absence of thermal stress, suggesting inhibition of the Calvin-Benson cycle by GA does not initiate bleaching in P. damicornis. In contrast, KCN did activate a bleaching response through symbiont expulsion, which occurred in the presence and absence of thermal stress. While KCN is an inhibitor of the Calvin-Benson cycle, it also promotes reactive oxygen species formation, and it is likely that this was the principal agent in the coral bleaching process. These findings do not support the hypothesis that temperature-induced inhibition of the Calvin-Benson cycle alone induces coral bleaching. © 2014. Published by The Company of Biologists Ltd.

  2. Inhibition of photosynthesis and bleaching of zooxanthellae by the coral pathogen Vibrio shiloi.

    Ben-Haim, Y; Banim, E; Kushmaro, A; Loya, Y; Rosenberg, E

    1999-06-01

    Vibrio shiloi is the causative agent of bleaching (loss of endosymbiotic zooxanthellae) of the coral Oculina patagonica in the Mediterranean Sea. To obtain information on the mechanism of bleaching, we examined the effect of secreted material (AK1-S) produced by V. shiloi on zooxanthellae isolated from corals. AK1-S caused a rapid inhibition of photosynthesis of the algae, as measured with a Mini-PAM fluorometer. The inhibition of photosynthesis was caused by (i) ammonia produced during the growth of V. shiloi on protein-containing media and (ii) a non-dialysable heat-resistant factor. This latter material did not inhibit photosynthesis of the algae by itself but, when added to different concentrations of NH4Cl, enhanced the inhibition approximately two- to threefold. Ammonia and the enhancer were effective to different degrees on zooxanthellae isolated from four species of coral examined. In addition to the rapid inhibition of photosynthesis, AK1-S caused bleaching (loss of pigmentation) and lysis of zooxanthellae. Bleaching was more rapid than lysis, reaching a peak (25% bleached algae) after 6 h. The factors in AK1-S responsible for bleaching and lysis were different from those responsible for the inhibition of photosynthesis, because they were heat sensitive, non-dialysable and active in the dark. Thus, the coral pathogen V. shiloi produces an array of extracellular materials that can inhibit photosynthesis, bleach and lyse zooxanthellae.

  3. Ion release from a composite resin after exposure to different 10% carbamide peroxide bleaching agents

    Renata Plá Rizzolo Bueno

    2012-06-01

    Full Text Available OBJECTIVE: This in vitro study evaluated the influence of two 10% carbamide peroxide bleaching agents - a commercial product (Opalescence PF; Ultradent Products, Inc. and a bleaching agent prepared in a compounding pharmacy - on the chemical degradation of a light-activated composite resin by determining its release of ions before and after exposure to the agents. MATERIAL AND METHODS: Thirty composite resin (Filtek Z250; 3M/ESPE samples were divided into three groups: group I (exposed to Opalescence PF commercial bleaching agent, group II (exposed to a compounded bleaching agent and group III (control - Milli-Q water. After 14 days of exposure, with a protocol of 8 h of daily exposure to the bleaching agents and 16 h of immersion in Milli-Q water, the analysis of ion release was carried out using a HP 8453 spectrophotometer. The values were analyzed statistically by ANOVA, Tukey's test and the paired t-tests. The significance level was set at 5%. RESULTS: After 14 days of the experiment, statistically significant difference was found between group II and groups I and III, with greater ion release from the composite resin in group II. CONCLUSIONS: The compounded bleaching agent had a more aggressive effect on the composite resin after 14 days of exposure than the commercial product and the control (no bleaching.

  4. Wastes from former mining and milling activities in Tajikistan

    Mirsaidov, U.M.

    2012-01-01

    This article is devoted to wastes from former mining and milling activities in Tajikistan. Currently, the serious radiological and ecological problems in Tajikistan are uranium mining and milling activities consequences overcoming which intensively developed during the soviet period. After the collapse of USSR, the uranic ores extraction in Tajikistan stopped due to deposit's output completion on the territory of the republic. Remediation of mining and milling activities' sites became the most urgent once all mines were closed.

  5. A bleaching earth from egyptian local deposits

    El Kinawy, Omayma S.

    2001-10-01

    Full Text Available The present investigation deals with the bleaching of vegetable oils using activated clays collected from some deposits in Egypt as compared to Tonsil FF currently used by local oil industry. The comparison was made; not only on the basis of the decolourising power of the earth, but also on the basis of its effects on the oil acidity, formation of the oil peroxides and the decomposition rate of the formed peroxides to aldehydes and ketones during the bleaching process. The activation of the collected earth samples was made using 4N HCl, 6N HCl and 30 % H2SO4. The bleaching tests of the activated samples were performed using the major four oil types processed in Egypt being cottonseed, sunflower, soybean and palm oils. In addition to the laboratory-evaluation tests, the performance of the activated samples, which showed promise on the lab-scale have been also tested on an industrial scale. The industrial application has proved that the activated local earth's can be successfully used as bleaching earth of local oils. Thus it can be used as a substitute of the varieties currently imported and used by the local oil sector.La presente investigación trata de la decoloración de aceites vegetales usando tierras activadas obtenidas de yacimientos egipcios, comparándola con el Tonsil FF usado normalmente en la industria oleícola local. La comparación se realizó, no sólo sobre la base del poder decolorante de la tierra, sino también sobre la base de sus efectos en la acidez del aceite, la formación de peróxidos y la velocidad de descomposición de los peróxidos formados en aldehidos y cetonas durante el proceso de decoloración. La activación de las muestras de tierras recogidas se hizo utilizando ClH 4N, ClH 6N y H2SO4 30 %. Los tests de decoloración de las muestras activadas se llevaron a cabo usando los cuatro tipos mayoritarios de aceites procesados en Egipto: aceite de semilla de algodón, de girasol, de soja y de palma. Además de los

  6. Waste management assessment and technical review programme. WATRP. An international peer review service for radioactive waste management activities

    1994-09-01

    International Atomic Energy Agency provides international peer review services in radioactive waste management to those Member States that have established radioactive waste management programmes. Such services are provided within Waste Management Assessment and Technical Review Programme (WATRP). The main objective of WATRP is to provide international expertise and information on a requested subject in the field of radioactive waste management and to validate that programmes and activities are sound and performing well. Refs, figs and tabs

  7. Characterization of selected waste tanks from the active LLLW system

    Keller, J.M.; Giaquinto, J.M.; Griest, W.H.

    1996-08-01

    From September 1989 through January of 1990, there was a major effort to sample and analyze the Active Liquid-Low Level Waste (LLLW) tanks at ORNL which include the Melton Valley Storage Tanks (MVST) and the Bethel Valley Evaporator Service Tanks (BVEST). The purpose of this report is to summarize additional analytical data collected from some of the active waste tanks from November 1993 through February 1996. The analytical data for this report was collected for several unrelated projects which had different data requirements. The overall analyte list was similar for these projects and the level of quality assurance was the same for all work reported. the new data includes isotopic ratios for uranium and plutonium and an evaluation of the denature ratios to address criticality concerns. Also, radionuclides not previously measured in these waste tanks, including 99Tc and 237Np, are provided in this report

  8. Technical baseline description of high-level waste and low-activity waste feed mobilization and delivery

    Papp, I.G.

    1997-01-01

    This document is a compilation of information related to the high-level waste (HLW) and low-activity waste (LAW) feed staging, mobilization, and transfer/delivery issues. Information relevant to current Tank Waste Remediation System (TWRS) inventories and activities designed to feed the Phase I Privatization effort at the Hanford Site is included. Discussions on the higher level Phase II activities are offered for a perspective on the interfaces

  9. Salt, chloride, bleach, and innate host defense

    Wang, Guoshun; Nauseef, William M.

    2015-01-01

    Salt provides 2 life-essential elements: sodium and chlorine. Chloride, the ionic form of chlorine, derived exclusively from dietary absorption and constituting the most abundant anion in the human body, plays critical roles in many vital physiologic functions, from fluid retention and secretion to osmotic maintenance and pH balance. However, an often overlooked role of chloride is its function in innate host defense against infection. Chloride serves as a substrate for the generation of the potent microbicide chlorine bleach by stimulated neutrophils and also contributes to regulation of ionic homeostasis for optimal antimicrobial activity within phagosomes. An inadequate supply of chloride to phagocytes and their phagosomes, such as in CF disease and other chloride channel disorders, severely compromises host defense against infection. We provide an overview of the roles that chloride plays in normal innate immunity, highlighting specific links between defective chloride channel function and failures in host defense. PMID:26048979

  10. Salt, chloride, bleach, and innate host defense.

    Wang, Guoshun; Nauseef, William M

    2015-08-01

    Salt provides 2 life-essential elements: sodium and chlorine. Chloride, the ionic form of chlorine, derived exclusively from dietary absorption and constituting the most abundant anion in the human body, plays critical roles in many vital physiologic functions, from fluid retention and secretion to osmotic maintenance and pH balance. However, an often overlooked role of chloride is its function in innate host defense against infection. Chloride serves as a substrate for the generation of the potent microbicide chlorine bleach by stimulated neutrophils and also contributes to regulation of ionic homeostasis for optimal antimicrobial activity within phagosomes. An inadequate supply of chloride to phagocytes and their phagosomes, such as in CF disease and other chloride channel disorders, severely compromises host defense against infection. We provide an overview of the roles that chloride plays in normal innate immunity, highlighting specific links between defective chloride channel function and failures in host defense. © Society for Leukocyte Biology.

  11. Development plan. High activity-long living wastes project. Abstract

    2007-01-01

    This brochure presents the actions that the ANDRA (the French national agency of radioactive wastes) has to implement in the framework of the project of high activity-long living (HALL) radioactive wastes (HAVL project) conformably to the requirements of the program defined in the law from June 28, 2006 (law no 2006-739). This law precises the three, complementary, research paths to explore for the management of this type of wastes: separation and transmutation of long-living radioactive elements, reversible disposal in deep geologic underground, and long duration storage. The ANDRA's action concerns the geologic disposal aspect. The following points are presented: the HALL wastes and their containers, the reversible disposal procedure, the HAVL project: financing of researches, storage concepts, development plan of the project (dynamics, information and dialogue approach, input data, main steps, schedule); the nine programs of the HAVL project (laboratory experiments and demonstration tests, surface survey, scientific program, simulation program, surface engineering studies and technological tests, information and communication program, program of environment and facilities surface observation and monitoring, waste packages management, monitoring and transport program, disposal program); the five transverse technical and scientific activities (safety, reversibility, cost, health and occupational safety, impact study). (J.S.)

  12. THE BLEACHING SYNDROME: MANIFESTATION OF A POST ...

    User

    universal and extends to the Americas and elsewhere impacted by colonial influences. Without exception .... "They say we should stop bleaching because of skin cancer and skin disease. ... Kenya, activists moved to have a ban put on the sale of skin bleaching creams. In agreement .... socioeconomic standing. Furthermore ...

  13. Anaerobic bioleaching of metals from waste activated sludge

    Meulepas, Roel J W

    2015-05-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342μgg-1 of copper, 487μgg-1 of lead, 793μgg-1 of zinc, 27μgg-1 of nickel and 2.3μgg-1 of cadmium. During the anaerobic acidification of 3gdry weightL-1 waste activated sludge, 80-85% of the copper, 66-69% of the lead, 87% of the zinc, 94-99% of the nickel and 73-83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead.

  14. This is how we manage Sweden's radioactive waste. Activities 1995

    1996-01-01

    SKB operates systems and facilities for the management and final disposal of spent nuclear fuel and other radioactive waste in Sweden. SKB has conducted extensive R, D and D work with regard to constructing a spent fuel encapsulation plant and a deep repository in crystalline bedrock. This annual report treats all the different activities without going into technical details

  15. BLEACHING IN VITAL TEETH: A LITERARY REVIEW

    Felipe Fagundes Soares

    2007-12-01

    Full Text Available Tooth bleaching technique has presented a significant evolution, promoting higher satisfaction and comfort to the patients. Therefore, the aim of this study was to present the bleaching agents and the techniques, discussing advantages and disadvantages of each one, and the effect of these agents in the oral environment. The main agents used in the bleaching technique are the hydrogen peroxide and the carbamide peroxide, promoting the bleaching effect through oxidation of organic compounds. The application of these agents can be made at home or at a doctor office. During treatment, it may occur some adverse effects, such as tooth sensibility, increasing of dental porosity, and some interactions with the restorative material. However, these adverse effects can be eliminated or controlled when the treatment is executed under professional orientation. When the bleaching technique is well indicated and correctly conducted, it is associated with significantly positive results.

  16. Side effects of external tooth bleaching

    Bruzell, E.M.; Pallesen, Ulla; Thoresen, N.R.

    2013-01-01

    Objective The study was performed to assess the risk of at-home and in-office bleaching procedures, and to recognise potential predictors for side effects. Design Multi-centre, questionnaire-based prospective study with follow-ups at around 14 days and around one year post-treatment. Setting...... General practices and university clinics during the years 2007‑2009 in Scandinavia. Subjects Patients with tooth bleaching as part of the treatment plan. Results The prevalence of experienced tooth sensitivity at first follow-up was independent of bleaching procedure (at-home = 50.3% [n = 143]; in...... attributed to the bleaching treatment in the at-home and in-office groups, respectively. Predictors for side effects were tooth sensitivity, surface loss and gingivitis when observed at inclusion. Treatment-related predictors were bleaching concentration and contact between tray and gingiva. Conclusions...

  17. Radioactive gaseous waste management activities at CWMF

    Sumangala, R.K; Cheralathan, M.; Hariharan, P.T.; Chitra, S.; Paul, B.

    2015-01-01

    HEPA and iodine filter banks are used as an important engineering safeguard to prevent the release of airborne activity to the environment during normal and accident conditions in all nuclear installations. CWMF is responsible for the periodical testing and certification these filter banks as per the technical specification of the nuclear facilities at Kalpakkam site. An efficiency of >99.9% is ensured for both the HEPA as well as iodine filter banks. The larger radioactive particulates are trapped in the micro glass fibre filter paper medium by the mechanism of interception and inertial impaction whereas particulates of submicron size are caught by diffusion. The major activity removed in particulate form is 137 Cs and 90 Sr. The elemental iodine is removed by physico-chemical adsorption on high surface area activated charcoal and organic compounds of iodine are removed by isotopic exchange with KI/KOH impregnated activated charcoal or silver impregnated silica gel. Silver impregnated molecular sieves 13-X and AR-1 were developed for the removal of iodine from reprocessing atmosphere. Studies on pressure swing adsorption technique have been carried out for isolating Argon from air. Using Molecular sieve 5A (45psi-50psi) and Carbon molecular sieves (100psi to 120psi) based PSA systems in series an enrichment of 30% Ar is possible. Pressurized Heavy Water Reactors with calandria vault coolant as air produces 41 Ar due to neutron activation of 40 Ar present in air which main contributor to the air is borne activity in MAPS, RAPS and Dhruva reactors. The isolated argon can be stored for decay and activity release can be minimized as per ALARA principle. (author)

  18. Anaerobic bioleaching of metals from waste activated sludge

    Meulepas, Roel J.W.; Gonzalez-Gil, Graciela; Teshager, Fitfety Melese; Witharana, Ayoma; Saikaly, Pascal E.; Lens, Piet N.L.

    2015-01-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342 μg g −1 of copper, 487 μg g −1 of lead, 793 μg g −1 of zinc, 27 μg g −1 of nickel and 2.3 μg g −1 of cadmium. During the anaerobic acidification of 3 g dry weight L −1 waste activated sludge, 80–85% of the copper, 66–69% of the lead, 87% of the zinc, 94–99% of the nickel and 73–83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead. - Highlights: • Heavy metals were leached during anaerobic acidification of waste activated sludge. • The process does not require the addition of chelating or oxidizing agents. • The metal leaching efficiencies (66 to 99%) were comparable to chemical leaching. • The produced leachate may be used for metal recovery and biogas production. • The produced digested sludge may be used as soil conditioner

  19. Anaerobic bioleaching of metals from waste activated sludge

    Meulepas, Roel J.W., E-mail: roel.meulepas@wetsus.nl [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Gonzalez-Gil, Graciela [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Thuwal 13955-69000 (Saudi Arabia); Teshager, Fitfety Melese; Witharana, Ayoma [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Saikaly, Pascal E. [King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Thuwal 13955-69000 (Saudi Arabia); Lens, Piet N.L. [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands)

    2015-05-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342 μg g{sup −1} of copper, 487 μg g{sup −1} of lead, 793 μg g{sup −1} of zinc, 27 μg g{sup −1} of nickel and 2.3 μg g{sup −1} of cadmium. During the anaerobic acidification of 3 g{sub dry} {sub weight} L{sup −1} waste activated sludge, 80–85% of the copper, 66–69% of the lead, 87% of the zinc, 94–99% of the nickel and 73–83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead. - Highlights: • Heavy metals were leached during anaerobic acidification of waste activated sludge. • The process does not require the addition of chelating or oxidizing agents. • The metal leaching efficiencies (66 to 99%) were comparable to chemical leaching. • The produced leachate may be used for metal recovery and biogas production. • The produced digested sludge may be used as soil conditioner.

  20. Activities of the IAEA in the area of radioactive waste management

    Efremenkov, V.M.

    1998-01-01

    The IAEA activity in the area of radioactive waste management mainly concentrates on three areas, namely: (i) the establishing of international principles and standards for the safe management of radioactive waste; (ii) to promote the development and improvements of waste processing technologies, including handling, treatment, conditioning, packaging, storage and disposal of waste; and (iii) assisting developing Member States in establishing good waste management practice through dissemination of technical information, providing technical support and training. These activities are carried out by the Waste Technology Section, Department of Nuclear Energy, and the Waste Safety Section, Department of Nuclear Safety. The Waste Technology Section's activities are organized into four subprogrammes covering: the handling, processing and storage of radioactive waste; radioactive waste disposal; technology and management aspects of decontamination, decommissioning and environmental restoration; and waste management information and support services

  1. Disposal Activities and the Unique Waste Streams at the Nevada National Security Site (NNSS)

    Arnold, P.

    2012-01-01

    This slide show documents waste disposal at the Nevada National Security Site. Topics covered include: radionuclide requirements for waste disposal; approved performance assessment (PA) for depleted uranium disposal; requirements; program approval; the Waste Acceptance Review Panel (WARP); description of the Radioactive Waste Acceptance Program (RWAP); facility evaluation; recent program accomplishments, nuclear facility safety changes; higher-activity waste stream disposal; and, large volume bulk waste streams

  2. Low-Activity Waste Feed Data Quality Objectives

    MJ Truex; KD Wiemers

    1998-12-11

    This document describes characterization requirements for the Tank Waste Remediation System (TWRS) Waste Disposal Program's privatization efforts in support of low-activity waste (LAW) treatment and immobilization, This revised Data Quality Objective (DQO) replaces earlier documents (PNNL 1997; DOE-W 1998zq Wiemers 1996). Revision O of this DQO was completed to meet Tri-Party Agreement (TPA) target milestone M-60-14-TO1. Revision 1 updates the data requirements based on the contract issued `August 1998 (DOE-RL 1998b). In addition, sections of Revision O pertaining to "environmental planning" were not acceptable to the Washington State Department of Ecology (Ecology) and have been removed. Regulatory compliance for TWRS Privatization is being addressed in a separate DQO (Wiemers et al. 1998). The Project Hanford Management Contract (PHMC) Contractors and the private contractor may elect to complete issue-specific DQOS to accommodate their individual work scope.

  3. Update of Nuclear Waste Policy Act transportation activities

    Callaghan, E.F.

    1987-01-01

    As directed by the Nuclear Waste Policy Act of 1982 (NWPA), the Department of Energy (DOE) is developing a nationwide system for transporting spent nuclear fuel and high-level radioactive waste from commercial power plants to deep geologic repositories for disposal. Plans for the transportation system will consider the following factors: the President's 1985 decision to co-locate some defense high-level waste with commercial waste in a repository, the NWPA requirement that the private sector be used to the fullest extent possible in developing and operating the system, and the possible approval by Congress of the DOE's proposal for a Monitored Retrievable Storage (MRS) facility, submitted in March 1987. (The MRS, if approved, would provide for the consolidation, packaging, and perhaps the temporary storage of spent fuel from reactors.) The ''Transportation Business Plan'', published in January 1986, reflects these considerations. The transportation system, when operational, will consist of two elements: (1) the cask system, which includes the transportation casks, the vehicular conveyances, tie-downs, and associated equipment for handling the casks; and (2) the transportation support system which is comprised of facilities, equipment, and services to support waste transportation. Development of the transportation system incorporates the following work elements: operational planning, support systems development, cash system development, systems analysis, and institutional activities. This paper focusses on the technical aspects of the system

  4. Radioactive waste packages stored at the Aube facility for low-intermediate activity wastes. A selective and controlled storage

    2005-01-01

    The waste package is the first barrier designed to protect the man and the environment from the radioactivity contained in wastes. Its design is thus particularly stringent and controlled. This brochure describes the different types of packages for low to intermediate activity wastes like those received and stored at the Aube facility, and also the system implemented by the ANDRA (the French national agency of radioactive wastes) and by waste producers to safely control each step of the design and fabrication of these packages. (J.S.)

  5. Optical Emission Spectroscopy of an Atmospheric Pressure Plasma Jet During Tooth Bleaching Gel Treatment.

    Šantak, Vedran; Zaplotnik, Rok; Tarle, Zrinka; Milošević, Slobodan

    2015-11-01

    Optical emission spectroscopy was performed during atmospheric pressure plasma needle helium jet treatment of various tooth-bleaching gels. When the gel sample was inserted under the plasma plume, the intensity of all the spectral features increased approximately two times near the plasma needle tip and up to two orders of magnitude near the sample surface. The color change of the hydroxylapatite pastille treated with bleaching gels in conjunction with the atmospheric pressure plasma jet was found to be in correlation with the intensity of OH emission band (309 nm). Using argon as an additive to helium flow (2 L/min), a linear increase (up to four times) of OH intensity and, consequently, whitening (up to 10%) of the pastilles was achieved. An atmospheric pressure plasma jet activates bleaching gel, accelerates OH production, and accelerates tooth bleaching (up to six times faster).

  6. 40 CFR 63.445 - Standards for the bleaching system.

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Standards for the bleaching system. 63... Standards for Hazardous Air Pollutants from the Pulp and Paper Industry § 63.445 Standards for the bleaching system. (a) Each bleaching system that does not use any chlorine or chlorinated compounds for bleaching...

  7. Maintenance Plan for the Hanford Immobilized Low-Activity Tank Waste Performance Assessment

    MANN, F.M.

    2000-01-01

    The plan for maintaining the Hanford Immobilized Low-Activity Tank Waste Performance Assessment (PA) is described. The plan includes expected work on PA reviews and revisions, waste reports, monitoring, other operational activities, etc

  8. Dissolution test for low-activity waste product acceptance

    Ebert, W. L.

    1998-01-01

    We have measured the mean and standard deviation of the solution concentrations of B, Na, and Si attained in replicate dissolution tests conducted at temperatures of 20, 40, and 70 C, for durations of 3 and 7 days, and at glass/water mass ratios of 1:10 and 1:1. These and other tests were conducted to evaluate the adequacy of the test methods specified in privatization contracts and to develop a data base that can be used to evaluate the reliability of reported results for tests performed on the waste products. Tests were conducted with a glass that we formulated to be similar to low-activity waste products that will be produced during the remediation of Hanford tank wastes. Statistical analyses indicated that, while the mean concentrations of B, Na, and Si were affected by the values of test parameters, the standard deviation of replicate tests was not. The precision of the tests was determined primarily by uncertainties in the analysis of the test solutions. Replicate measurements of other glass properties that must be reported for Hanford low-activity waste products were measured to evaluate the possible adoption of the glass used in these tests as a standard test material for the product acceptance process

  9. Characterization of activated carbon produced from urban organic waste

    Abdul Gani Haji

    2013-10-01

    Full Text Available The difficulties to decompose organic waste can be handled naturally by pyrolisis so it can  decomposes quickly that produces charcoal as the product. This study aims to investigate the characteristics of activated carbon from urban organic waste. Charcoal results of pyrolysis of organic waste activated with KOH 1.0 M at a temperature of 700 and 800oC for 60 to 120 minutes. Characteristics of activated carbon were identified by Furrier Transform Infra Red (FTIR, Scanning Electron Microscopy (SEM, and X-Ray Diffraction (XRD. However, their quality is determined yield, moisture content, ash, fly substances, fixed carbon, and the power of adsorption of iodine and benzene. The identified functional groups on activated carbon, such as OH (3448,5-3436,9 cm-1, and C=O (1639,4 cm-1. In general, the degree and distance between the layers of active carbon crystallites produced activation in all treatments showed no significant difference. The pattern of activated carbon surface topography structure shows that the greater the pore formation in accordance with the temperature increase the more activation time needed. The yield of activated carbon obtained ranged from 72.04 to 82.75%. The results of characterization properties of activated carbon was obtained from 1.11 to 5.41% water, 13.68 to 17.27% substance fly, 20.36 to 26.59% ash, and 56.14 to 62.31% of fixed carbon . Absorption of activated carbon was good enough at 800oC and 120 minutes of activation time, that was equal to 409.52 mg/g of iodine and 14.03% of benzene. Activated carbon produced has less good quality, because only the water content and flying substances that meet the standards.Doi: 10.12777/ijse.5.2.89-94 [How to cite this article: Haji, A.G., Pari, G., Nazar, M., and Habibati.  (2013. Characterization of activated carbon produced from urban organic waste . International Journal of Science and Engineering, 5(2,89-94. Doi: 10.12777/ijse.5.2.89-94

  10. Hospitalar radioactive waste of low activity, a daily practice

    Rezio, M.T.; Vieira, M.R. [Instituto Portugues de Oncologia de Francisco Gentil - CROL, Lisboa (Portugal)

    2006-07-01

    Introduction According to the law we should have a specific area for storing and treating waste. That area should have special containers for temporary storage in order to assure the radioactive decay for all the radioactive waste, biological contaminated or non biological and in solid or liquid form. According with that law the limits established for discharge are: For solid waste, we must not discharge more than 370 MBq in a minimum volume of 0,1 m{sup 3} and is not allowed waste with activities higher than 3,7 kBq; For liquid waste discharges from the department to the public sewer, the average concentrations calculated taking into account the water flow of the sewer system that serves the installation, should be the following:The annual medium concentration must not exceed 3 times the reference concentration (C.R.) for that nuclide; The monthly medium concentration must not exceed 15 times the reference concentration (C.R.); The daily medium concentration must not exceed 60 times the reference concentration (C.R.); The reference concentration (C.R.), expressed in Bq.m{sup -3}, should be calculated taking into account the relevant incorporation per ingestion. The calculation of C.R. in liquid waste should have into account the following: For the general public the effective dose E achieved, per ingestion by an individual in the group of age g is determined according to the following formula(1):E= {sigma}{sub i} h(g){sub j,ing} X J{sub j,ing}, where h(g){sub j,ing} is the committed effective dose per unit-intake for the ingested radionuclide j (Sv/Bq) by an individual in the group of age g; J{sub j,ing} is the relevant intake via ingestion of the radionuclide j (Bq). The effective dose E achieved by an individual in the group of age g should not be higher than 0,1 mSv/year. If the average water volume ingested by an individual adult is 800 l, the value J{sub j,ing}, calculated by the formula (1) should be referred to 1000 l, in order to obtain the C.R., for the

  11. [Assessment of tooth bleaching efficacy with spectrophotometer].

    Zhu, Wenhao; Liu, Chang; Pan, Jie

    2014-06-01

    To analyze the changes in CIE L*, a*, and b* at cervical, body, and incisal sites after tooth bleaching by using a spectrophotometer. Sixty-seven intact and healthy maxillary central incisors were in-vestigated. These incisors were darker than A3 according to the Vita Classical shade guide. The CIE tooth shade parameters L*, a*, and b* were simultaneously recorded at three tooth areas (cervical, body, and incisal) with a spectrophotometer before and after tooth bleaching (35%H2O2 coordinating with Beyond whitening accelerator irradiating). The shade dif-ferential (DeltaE) was calculated. ANOVA, paired t-test, and Pearson correlation analysis were used for data analysis. The efficacy rates of tooth bleaching were satisfactory, with 86.6%, 86.6%, and 85.1% in the cervical, body, and incisal sites, respectively. The average values of DeltaE were 5.09, 4.44, and 4.40 in the cervical, body, and incisal sites. Tooth bleaching significantly increased L* and significantly decreased a* and b* in all tooth areas (P spectrophotometer could objectively evaluate the whitening effect of tooth bleaching at the different tooth sites. The tooth bleaching system (35%H202 coordinating with Beyond whitening accelerator irradiating) exerts powerful bleaching actions in most of the tooth areas investigated. The order of tooth bleaching effectiveness is cervicalbody>incisal. Yellow coloration is decreased mainly at the cervical site, and brightness was increased mostly at theincisal site. The effectiveness of tooth bleaching increases as the baseline b* value increases.

  12. State and Federal activities on low-level waste

    1983-01-01

    With the passage of the Low-Level Waste Policy Act in December 1980, the states have assumed the management responsibility and the federal government has become a facilitator. State and Federal roles in regulation have not altered. This paper reviews the developments over the last two years to point out the progress made and critical steps that lie ahead. Both technological and political aspects are covered, and a conclusion is presented with a look to the future. Since compact development in the tool chosen by the politicans for low-level waste management, the author reviews the present status starting with the northwest compact which has been introduced into the House and Senate and is subject to hearings. The past two years have seen real progress in technology in the broadest sense. An information development and dissemination system was established in 1978 wih the state-by-state assessment of low-level waste disposal. Annual examinations have been made through 1981 which enables one to understand the generation of low-level wastes. Policy level planning by states can be supported by the base level of information available. Incineration of dry active waste and other non-fuel cycle waste is ready to be fully accepted. Much work has been done on volume reduction of liquids. The increased understanding of the ways to make a disposal site work represents a major technolological improvement. Within the DOE system, there is beginning to be a real understanding of the critical parameters in disposal site performance in the East

  13. Mill Designed Bio bleaching Technologies

    Institute of Paper Science Technology

    2004-01-30

    A key finding of this research program was that Laccase Mediator Systems (LMS) treatments on high-kappa kraft could be successfully accomplished providing substantial delignification (i.e., > 50%) without detrimental impact on viscosity and significantly improved yield properties. The efficiency of the LMS was evident since most of the lignin from the pulp was removed in less than one hour at 45 degrees C. Of the mediators investigated, violuric acid was the most effective vis-a-vis delignification. A comparative study between oxygen delignification and violuric acid revealed that under relatively mild conditions, a single or a double LMS{sub VA} treatment is comparable to a single or a double O stage. Of great notability was the retention of end viscosity of LMS{sub VA} treated pulps with respect to the end viscosity of oxygen treated pulps. These pulps could then be bleached to full brightness values employing conventional ECF bleaching technologies and the final pulp physical properties were equal and/or better than those bleached in a conventional ECF manner employing an aggressively O or OO stage initially. Spectral analyses of residual lignins isolated after LMS treated high-kappa kraft pulps revealed that similar to HBT, VA and NHA preferentially attack phenolic lignin moieties. In addition, a substantial decrease in aliphatic hydroxyl groups was also noted, suggesting side chain oxidation. In all cases, an increase in carboxylic acid was observed. Of notable importance was the different selectivity of NHA, VA and HBT towards lignin functional groups, despite the common N-OH moiety. C-5 condensed phenolic lignin groups were overall resistant to an LMS{sub NHA, HBT} treatments but to a lesser extent to an LMS{sub VA}. The inactiveness of these condensed lignin moieties was not observed when low-kappa kraft pulps were biobleached, suggesting that the LMS chemistry is influenced by the extent of delignification. We have also demonstrated that the current

  14. Biohydrogen production using waste activated sludge disintegrated by gamma irradiation

    Yin, Yanan; Wang, Jianlong

    2015-01-01

    Highlights: • The waste activated sludge could be disintegrated by gamma irradiation. • The disintegrated sludge could be used for biohydrogen production. • Combined alkali-irradiation treatment achieved the highest solubilization of sludge. - Abstract: The biohydrogen production using the disintegrated and dissolved sludge by gamma irradiation was studied. The experimental results showed that gamma irradiation and irradiation combined with alkali pretreatment could disintegrate and dissolve waste activated sludge for biohydrogen production. The alkali-irradiation treatment of the sludge at pH = 12 and 20 kGy achieved the highest disintegration and dissolution, i.e., it could destroy the cell walls and release organic matters (such as soluble COD, polysaccharides and protein) into the solution. The disintegrated sludge could be used as a low-cost substrate for biohydrogen production

  15. Effect of laser-assisted bleaching with Nd:YAG and diode lasers on shear bond strength of orthodontic brackets.

    Mirhashemi, Amirhossein; Emadian Razavi, Elham Sadat; Behboodi, Sara; Chiniforush, Nasim

    2015-12-01

    The aim of the present study was to assess the effect of laser-assisted bleaching with neodymium:yttrium-aluminum-garnet (Nd:YAG) and diode lasers on shear bond strength (SBS) of orthodontic brackets. One hundred and four extracted human premolars were randomly divided into four groups: group 1: No bleaching applied (control group); group 2: Teeth bleached with 40 % hydrogen peroxide; group 3: Teeth treated with 30 % hydrogen peroxide activated with Nd:YAG laser (1064 nm, 2.5 W, 25 Hz, pulse duration of 100 μs, 6 mm distance); and group 4: Teeth treated with 30 % hydrogen peroxide activated with diode laser (810 nm, 1 W, CW, 6 mm distance). Equal numbers of teeth in groups 2, 3, and 4 were bonded at start, 1 h, 24 h, and 1 week after bleaching. A universal testing machine measured the SBS of the samples 24 h after bonding. After bracket debonding, the amount of residual adhesive on the enamel surface was observed under a stereomicroscope to determine the adhesive remnant index (ARI) scores. The SBS in the unbleached group was significantly higher than that in the bleached groups bonded immediately and 1 h after laser-assisted bleaching (P laser-assisted bleaching, the SBS was found to be significantly lower than that in the control group. Significant differences in the ARI scores existed among groups as well. The SBS of brackets seems to increase quickly within an hour after laser-assisted bleaching and 24 h after conventional bleaching. Thus, this protocol can be recommended if it is necessary to bond the brackets on the same day of bleaching.

  16. Activity measurement algorithm in solid radioactive waste clearance procedure

    Hinca, R.; Skala, L.

    2014-01-01

    Most of European metrology experts prefer in radiation wastes characterization process to use scaling factor method in combination with high definition gamma spectrometry rather than radionuclide vector method in combination with gross gamma activity measurement. The second method is actually used in Slovakian nuclear facilities. The international (IAEA) and Slovak national authorities (UVZ) recognize both approach but there is a fact, that high definition gamma spectrometry radionuclides more properly. (authors)

  17. Briefing book on environmental and waste management activities

    Quayle, T.A.

    1993-04-01

    The purpose of the Briefing Book is to provide current information on Environmental Restoration and Waste Management Activities at the Hanford Site. Each edition updates the information in the previous edition by deleting those sections determined not to be of current interest and adding new topics to keep up to date with the changing requirements and issues. This edition covers the period from October 15, 1992 through April 15, 1993

  18. ''Cold crucible'' vitrification projects for low and high active waste

    Roux, P.; Jouan, A.

    1998-01-01

    In continuity of the CEA HLW vitrification process experienced for more than 20 years in industrial operations in Cogema reprocessing plants (Marcoule and La Hague), CEA has developed an advanced extended performance cold crucible glass melter to address a wider range of waste like LLW, ILW and in particular waste with very corrosive species or requiring glass with higher elaboration temperature. In the cold crucible melter the bath of molten glass is directly heated by induction while the walls are cooled in order to freeze a protective glass layer. This technology subsequently allows high glass throughput while keeping the flexibility, the maintainability and low secondary waste generation related to a small metallic melter. Its recent use in the glass industry and the thousands of hours of pilot tests performed on inactive surrogates have demonstrated the maturity of this technology and its flexibility of use for processing most of the waste generated at nuclear facilities. SGN has therefore proposed this technology in Italy and Korea and in USA in the frame of the Hanford Privatization phase 1 A feasibility study. Main features of this study but also tests results with Hanford surrogates and active samples are discussed. (author)

  19. The effect of baking soda when applied to bleached enamel prior to restorative treatment.

    Tostes, Bhenya Ottoni; Mondelli, Rafael Francisco Lia; Lima-Arsati, Ynara Bosco de Oliveira; Rodrigues, Jose Augusto; Costa, Leonardo Cesar

    2013-08-01

    This in vitro study evaluated the effect of 10% baking soda solution and sodium bicarbonate powder (applied with jets) when applied to bleached enamel prior to restorative treatment. The surfaces of 40 bovine incisors were flattened and divided into 5 groups (n = 8): Group B (bleached and restored, negative control), Group W (bleached, stored in distilled water for 7 days, and restored), Group BSJ (bleached, abraded with baking soda jet for 1 min, and restored), Group BSS (bleached, application of 10% baking soda solution for 5 min, and restored), and Group R (restored, without bleaching, positive control). The samples were bleached in 1 session with 3 applications of 35% HP-based gel and activated with a LED appliance for 9 min each. Resin composite cylinders (2 mm height and 0.8 mm diameter) were made on the enamel surface after the acid etching and a conventional 1-step single vial adhesive application was performed. After storage in distilled water (37 ± 1°C, 24 hr), the microshear bond test was performed (1 mm/min). ANOVA and Tukey tests were applied to compare the results. The mean results of these tests showed that Groups W, BBS, and R were not statistically different. These groups also indicated a higher bond strength when compared with Groups B and BSJ. The application of 10% baking soda solution for 5 min may be an alternative pre-restorative treatment for bleached enamel, but further studies are needed to consider whether or not this treatment may be effectively used in clinical practice.

  20. Influence of pH, bleaching agents, and acid etching on surface wear of bovine enamel

    Soares, Ana Flávia; Bombonatti, Juliana Fraga Soares; Alencar, Marina Studart; Consolmagno, Elaine Cristina; Honório, Heitor Marques; Mondelli, Rafael Francisco Lia

    2016-01-01

    ABSTRACT Development of new materials for tooth bleaching justifies the need for studies to evaluate the changes in the enamel surface caused by different bleaching protocols. Objective The aim of this study was to evaluate the bovine dental enamel wear in function of different bleaching gel protocols, acid etching and pH variation. Material and Methods Sixty fragments of bovine teeth were cut, obtaining a control and test areas. In the test area, one half received etching followed by a bleaching gel application, and the other half, only the bleaching gel. The fragments were randomly divided into six groups (n=10), each one received one bleaching session with five hydrogen peroxide gel applications of 8 min, activated with hybrid light, diode laser/blue LED (HL) or diode laser/violet LED (VHL) (experimental): Control (C); 35% Total Blanc Office (TBO35HL); 35% Lase Peroxide Sensy (LPS35HL); 25% Lase Peroxide Sensy II (LPS25HL); 15% Lase Peroxide Lite (LPL15HL); and 10% hydrogen peroxide (experimental) (EXP10VHL). pH values were determined by a pHmeter at the initial and final time periods. Specimens were stored, subjected to simulated brushing cycles, and the superficial wear was determined (μm). ANOVA and Tukey´s tests were applied (α=0.05). Results The pH showed a slight decrease, except for Group LPL15HL. Group LPS25HL showed the highest degree of wear, with and without etching. Conclusion There was a decrease from the initial to the final pH. Different bleaching gels were able to increase the surface wear values after simulated brushing. Acid etching before bleaching increased surface wear values in all groups. PMID:27008254

  1. The potential significance of microbial activity in radioactive waste disposal

    McCabe, A.M.

    1987-12-01

    The aim of this report is to assess the potential significance of microbial activity in radioactive waste disposal. It outlines the major factors which need to be considered in order to evaluate the importance of microbiological action. These include water and nutritional sources (particularly carbon) hostile conditions (particularly the effects of radiation and pH), the establishment of pH micro-environments and the degradative effect of microbial metabolic by-products on the disposed waste forms. Before an active microbial population can develop there are certain basic requirements for life. These are outlined and the possibility of colonisation occurring within the chemical, radiological and nutritional constraints of a repository are considered. Once colonisation is assumed, the effect of microbial activity is discussed under five headings, i.e. (i) direct attack, (ii) physical disruption (which includes consideration of fissuring processes and void formation), (iii) gas generation (which may be of particular importance), (iv) radionuclide uptake and finally (v) alteration of groundwater chemistry. Particular attention is paid to the possibility of environments becoming established both within the waste form itself (allowing microbes to attack from the inside of the repository outward) or attack on the encapsulant materials (microbes attacking from the outside inward). (author)

  2. Recycling of radioactive mineral waste by activity separation

    Schartmann, F.; Cramer, T.; Meier-Kortwig, J.; Diedenhofen, S.; Wotruba, H.

    2005-01-01

    The AST process is a device for the recycling of building rubble originating from the dismantling of nuclear installations. Due to the activity separation in the process, a major part of rubble which would have otherwise been radioactive waste can now be cleared. The AST process has been developed in the course of the combined research project ''Aufbereitung radioaktiver mineralischer Rueckstaede durch Aktivitaetsseparation (Recycling of radioactive mineral waste by activity separation)'' which was sponsored by the BMBF (Federal Ministry for Education and Research). The first step was to investigate the activity distribution between the various constituents of activated heavy concrete (additions: hematite, magnetite, iron cuttings), of contaminated heavy and normal concrete, as well as of composition floor. Heavy concrete with metal additions showed a selective activation of the various constituents. Contaminated rubble often exhibits a selective enrichment of the activity in the cement in contrast to the aggregate. The AST facility for activity separation was designed on the basis of these results. Trial operation with various types of building rubble was carried out using three methods for sorting, screening according to grain size, magnetic separation and radiometric sorting. The use of these three methods was adapted to the material. (orig.)

  3. Influence of bleaching agents on surface roughness of sound or eroded dental enamel specimens.

    Azrak, Birgül; Callaway, Angelika; Kurth, Petra; Willershausen, Brita

    2010-12-01

    The aim of the present in vitro study was to assess the effect of bleaching agents on eroded and sound enamel specimens. Enamel specimens prepared from human permanent anterior teeth were incubated with different bleaching agents containing active ingredients as 7.5 or 13.5% hydrogen peroxide or 35% carbamide peroxide, ranging in pH from 4.9 to 10.8. The effect of the tooth whitening agents on surface roughness was tested for sound enamel surfaces as well as for eroded enamel specimens. To provoke erosive damage, the enamel specimens were incubated for 10 hours with apple juice (pH = 3.4). Afterwards, pretreated and untreated dental slices were incubated with one of the bleaching agents for 10 hours. The surface roughness (R(a)) of all enamel specimens (N = 80) was measured using an optical profilometric device. A descriptive statistical analysis of the R(a) values was performed. The study demonstrated that exposure to an acidic bleaching agent (pH = 4.9) resulted in a higher surface roughness (p = 0.043) than treatment with a high peroxide concentration (pH = 6.15). If the enamel surface was previously exposed to erosive beverages, subsequent bleaching may enhance damage to the dental hard tissue. Bleaching agents with a high concentration of peroxide or an acidic pH can influence the surface roughness of sound or eroded enamel. © 2010, COPYRIGHT THE AUTHORS. JOURNAL COMPILATION © 2010, WILEY PERIODICALS, INC.

  4. An Effective Ostrich Oil Bleaching Technique Using Peroxide Value as an Indicator

    Gan Seng Chiew

    2011-07-01

    Full Text Available Ostrich oil has been used extensively in the cosmetic and pharmaceutical industries. However, rancidity causes undesirable chemical changes in flavour, colour, odour and nutritional value. Bleaching is an important process in refining ostrich oil. Bleaching refers to the removal of certain minor constituents (colour pigments, free fatty acid, peroxides, odour and non-fatty materials from crude fats and oils to yield purified glycerides. There is a need to optimize the bleaching process of crude ostrich oil prior to its use for therapeutic purposes. The objective of our study was to establish an effective method to bleach ostrich oil using peroxide value as an indicator of refinement. In our study, we showed that natural earth clay was better than bentonite and acid-activated clay to bleach ostrich oil. It was also found that 1 hour incubation at a 150 °C was suitable to lower peroxide value by 90%. In addition, the nitrogen trap technique in the bleaching process was as effective as the continuous nitrogen flow technique and as such would be the recommended technique due to its cost effectiveness.

  5. Sizing and melting development activities using noncontaminated metal at the Waste Experimental Reduction Facility

    Larsen, M.M.; Logan, J.A.

    1984-05-01

    EG and G Idaho, Inc., has established the Waste Experimental Reduction Facility (WERF) at the Idaho National Engineering Laboratory (INEL) to develop the capability to reduce the volume that low-level beta/gamma wastes occupy at the disposal site. The work effort at WERF includes a waste sizing development activity (WSDA), a waste melting development activity (WMDA), and a waste incineration development activity (WIDA). This report describes work and developments to date in the WSDA and WMDA with noncontaminated metallic waste in preparation for operations at WERF involving beta/gamma-contaminated metal

  6. Don't bleach chaotic data

    Theiler, J.; Eubank, S.

    1993-01-01

    A common first step in time series signal analysis involves digitally filtering the data to remove linear correlations. The residual data is spectrally white (it is ''bleached''), but in principle retains the nonlinear structure of the original time series. It is well known that simple linear autocorrelation can give rise to spurious results in algorithms for estimating nonlinear invariants, such as fractal dimension and Lyapunov exponents. In theory, bleached data avoids these pitfalls. But in practice, bleaching obscures the underlying deterministic structure of a low-dimensional chaotic process. This appears to be a property of the chaos itself, since nonchaotic data are not similarly affected. The adverse effects of bleaching are demonstrated in a series of numerical experiments on known chaotic data. Some theoretical aspects are also discussed

  7. LOW ACTIVITY WASTE FEED SOLIDS CARACTERIZATION AND FILTERABILITY TESTS

    McCabe, D.; Crawford, C.; Duignan, M.; Williams, M.; Burket, P.

    2014-04-03

    The primary treatment of the tank waste at the DOE Hanford site will be done in the Waste Treatment and Immobilization Plant (WTP) that is currently under construction. The baseline plan for the WTP Pretreatment facility is to treat the waste, splitting it into High Level Waste (HLW) feed and Low Activity Waste (LAW) feed. Both waste streams are then separately vitrified as glass and sealed in canisters. The LAW glass will be disposed onsite in the Integrated Disposal Facility (IDF). There are currently no plans to treat the waste to remove technetium in the WTP Pretreatment facility, so its disposition path is the LAW glass. Options are being explored to immobilize the LAW portion of the tank waste, i.e., the LAW feed from the WTP Pretreatment facility. Removal of {sup 99}Tc from the LAW Feed, followed by off-site disposal of the {sup 99}Tc, would eliminate a key risk contributor for the IDF Performance Assessment (PA) for supplemental waste forms, and has potential to reduce treatment and disposal costs. Washington River Protection Solutions (WRPS) is developing some conceptual flow sheets for LAW treatment and disposal that could benefit from technetium removal. One of these flowsheets will specifically examine removing {sup 99}Tc from the LAW feed stream to supplemental immobilization. The conceptual flow sheet of the {sup 99}Tc removal process includes a filter to remove insoluble solids prior to processing the stream in an ion exchange column, but the characteristics and behavior of the liquid and solid phases has not previously been investigated. This report contains results of testing of a simulant that represents the projected composition of the feed to the Supplemental LAW process. This feed composition is not identical to the aqueous tank waste fed to the Waste Treatment Plant because it has been processed through WTP Pretreatment facility and therefore contains internal changes and recycle streams that will be generated within the WTP process. Although

  8. Mixed-waste minimization activities in the nuclear weapons complex

    Marchetti, J.A.; Suffern, J.S.

    1991-01-01

    Over the past 40 years, the US Department of Energy (DOE) and the nuclear weapons complex have successfully executed their mission of providing the country with a strong nuclear deterrent. Now, however, they must attain another mission at the same time: to eliminate or greatly reduce the environmental, safety, and health problems in the complex. Mixed-waste minimization activities have taken place in 11 of the complex production plants and laboratories: the Pinellas plant, the Mount plant, the Kansas City plant, the Y-12 plant, the Rocky Flats plant, the Savannah River Site (SRS), the Savannah River Site (SRS), the Pantex plant, the Nevada Test Site, Sandia National Laboratories, Los Alamos National Laboratory, and the Lawrence Livermore National Laboratory. The mixed-waste minimization opportunities that have been implemented to date by the production facilities are different from those that have been implemented by the laboratories. Areas of opportunity at the plants involve the following activities: (1) process design or improvement; (2) substitution of materials; (3) waste segregation; (4) recycling; and (5) administrative controls

  9. Alkali activated slag cements using waste glass as alternative activators. Rheological behaviour

    Manuel Torres-Carrasco

    2015-03-01

    The findings show that AAS paste behaviour of rheology when the activator was a commercial waterglass solution or NaOH/Na2CO3 with waste glass was similar, fit the Herschel-Bulkley model. The formation of primary C-S-H gel in both cases were confirmed. However, the rheological behaviour in standard cements fit the Bingham model. The use of the waste glass may be feasible from a rheological point of view in pastes can be used.

  10. State-of-the-art dry active waste processing facility

    Hillmer, T.; Ingalsbe, H.; Alcorn, G.; Anderson, K.; Dahlen, D.

    1989-01-01

    Palo Verde Nuclear Generating Station (PVNGS) is operated by Arizona Public Service for a consortium of seven owners. The site consists of three identical single unit power plants. Each unit is a Combustion Engineering Series 80 pressurized water reactor (PWR) rated at 1270 Megawatts electric. The site is located 100 kilometers west of Phoenix, Arizona in the arid southwest desert region of the United States of America. Since the start up of Unit One in 1985, Palo Verde has aggressively pursued waste volume reduction. This includes a dry active waste (DAW) segregation program that locates and separates nonradioactive and reusable materials that have been mixed with the radioactive DAW. The DAW program is described in further detail in the paper

  11. Fluidized bed steam reformed mineral waste form performance testing to support Hanford Supplemental Low Activity Waste Immobilization Technology Selection

    Jantzen, C. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pierce, E. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Cozzi, A. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Crawford, C. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Daniel, W. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Herman, C. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Miller, D. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Missimer, D. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, C. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Brown, C. F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Qafoku, N. P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Neeway, J. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Valenta, M. M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gill, G. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Swanberg, D. J. [Washington River Protection Solutions (WRPS), Richland, WA (United States); Robbins, R. A. [Washington River Protection Solutions (WRPS), Richland, WA (United States); Thompson, L. E. [Washington River Protection Solutions (WRPS), Richland, WA (United States)

    2015-10-01

    This report describes the benchscale testing with simulant and radioactive Hanford Tank Blends, mineral product characterization and testing, and monolith testing and characterization. These projects were funded by DOE EM-31 Technology Development & Deployment (TDD) Program Technical Task Plan WP-5.2.1-2010-001 and are entitled “Fluidized Bed Steam Reformer Low-Level Waste Form Qualification”, Inter-Entity Work Order (IEWO) M0SRV00054 with Washington River Protection Solutions (WRPS) entitled “Fluidized Bed Steam Reforming Treatability Studies Using Savannah River Site (SRS) Low Activity Waste and Hanford Low Activity Waste Tank Samples”, and IEWO M0SRV00080, “Fluidized Bed Steam Reforming Waste Form Qualification Testing Using SRS Low Activity Waste and Hanford Low Activity Waste Tank Samples”. This was a multi-organizational program that included Savannah River National Laboratory (SRNL), THOR® Treatment Technologies (TTT), Pacific Northwest National Laboratory (PNNL), Oak Ridge National Laboratory (ORNL), Office of River Protection (ORP), and Washington River Protection Solutions (WRPS). The SRNL testing of the non-radioactive pilot-scale Fluidized Bed Steam Reformer (FBSR) products made by TTT, subsequent SRNL monolith formulation and testing and studies of these products, and SRNL Waste Treatment Plant Secondary Waste (WTP-SW) radioactive campaign were funded by DOE Advanced Remediation Technologies (ART) Phase 2 Project in connection with a Work-For-Others (WFO) between SRNL and TTT.

  12. Development of Simulants to Support Mixing Tests for High Level Waste and Low Activity Waste

    EIBLING, RUSSELLE.

    2004-01-01

    The objectives of this study were to develop two different types of simulants to support vendor agitator design studies and mixing studies. The initial simulant development task was to develop rheologically-bounding physical simulants and the final portion was to develop a nominal chemical simulant which is designed to match, as closely as possible, the actual sludge from a tank. The physical simulants to be developed included a lower and upper rheologically bounded: pretreated low activity waste (LAW) physical simulant; LAW melter feed physical simulant; pretreated high level waste (HLW) physical simulant; HLW melter feed physical simulant. The nominal chemical simulant, hereafter referred to as the HLW Precipitated Hydroxide simulant, is designed to represent the chemical/physical composition of the actual washed and leached sludge sample. The objective was to produce a simulant which matches not only the chemical composition but also the physical properties of the actual waste sample. The HLW Precipitated Hydroxide simulant could then be used for mixing tests to validate mixing, homogeneity and representative sampling and transferring issues. The HLW Precipitated Hydroxide simulant may also be used for integrated nonradioactive testing of the WTP prior to radioactive operation

  13. Fracture resistance of teeth submitted to several internal bleaching protocols.

    Leonardo, Renato de Toledo; Kuga, Milton Carlos; Guiotti, Flávia Angélica; Andolfatto, Carolina; Faria-Júnior, Norberto Batista de; Campos, Edson Alves de; Keine, Kátia Cristina; Dantas, Andrea Abi Rached

    2014-03-01

    The aim of this study was to evaluate the fracture resistance of teeth submitted to several internal bleaching protocols using 35% hydrogen peroxide (35HP), 37% carbamide peroxide (37CP), 15% hydrogen peroxide with titanium dioxide nanoparticles (15HPTiO2) photoactivated by LED-laser or sodium perborate (SP). After endodontic treatment, fifty bovine extracted teeth were divided into five groups (n = 10): G1-unbleached; G2-35HP; G3-37CP; G4-15HPTiO2 photoactivated by LED-laser and G5-SP. In the G2 and G4, the bleaching protocol was applied in 4 sessions, with 7 days intervals between each session. In the G3 and G5, the materials were kept in the pulp teeth for 21 days, but replaced every 7 days. After 21 days, the teeth were subjected to compressive load at a cross head speed of 0.5 mm/min, applied at 135° to the long axis of the root using an eletromechanical testing machine, until teeth fracture. The data were submitted to ANOVA and Tukey tests (α = 5%). The 35HP, 37CP, 15HPTiO2 and SP showed similar fracture resistance teeth reduction (p > 0.05). All bleaching treatments reduced the fracture resistance compared to unbleached teeth (p endodontically-treated teeth, but there were no differences between each other. There are several internal bleaching protocols using hydrogen peroxide in different concentrations and activation methods. This study evaluated its effects on fracture resistance in endodontically-treated teeth.

  14. Comparative study of the action of two different types of bleaching agents activated by two different types of irradiation fonts: xenon plasma arc lamp and 960 nm diode laser

    Walverde, Debora Ayala

    2001-01-01

    This in vitro study compares two different types of tooth bleaching agents stimulated with two different irradiation fonts. These fonts accelerate the action of the bleaching agents upon the enamel surface by heating up the materials. We used the xenon plasma arc lamp and a 960 nm fiber-coupled diode laser to irradiate the two materials containing 35% of hydrogen peroxide (Opus White and Opalescence extra). The color of the teeth was measured with a spectrophotometer using the CIELAB color system that gives the numeric values of L * a * b * . (author)

  15. Volume reduction of dry active waste by use of a waste sorting table at the Brunswick nuclear power plant

    Snead, P.B.

    1988-01-01

    Carolina Power and Light Company's Brunswick nuclear power plant has been using a National Nuclear Corporation Model WST-18 Waste Sorting Table to monitor and sort dry active waste for segregating uncontaminated material as a means of low-level waste volume reduction. The WST-18 features 18 large-area, solid scintillation detectors arranged in a 3 x 6 array underneath a sorting/monitoring surface that is shielded from background radiation. An 11-week study at Brunswick showed that the use of the waste sorting table resulted in dramatic improvements in both productivity (man-hours expended per cubic foot of waste processed) and monitoring quality over the previous hand-probe frisking method. Use of the sorting table since the study has confirmed its effectiveness in volume reduction. The waste sorting table paid for its operation in volume reduction savings alone, without accounting for the additional savings from recovering reusable items

  16. Data Packages for the Hanford Immobilized Low-Activity Tank Waste Performance Assessment: 2001 Version

    MANN, F.M.

    2000-01-01

    Data package supporting the 2001 Immobilized Low-Activity Waste Performance Analysis. Geology, hydrology, geochemistry, facility, waste form, and dosimetry data based on recent investigation are provided. Verification and benchmarking packages for selected software codes are provided

  17. Assessment of bleaching of K-feldspar grains

    Zhang Jiafu; Li Shenghua; Tso, M-Y.W.

    2001-01-01

    Based on the difference in the bleaching rate between IRSL and TL signals, a new method of assessing the bleaching of sedimentary feldspar is proposed. All measurements for De and the bleaching factor (normalized ratio of IRSL to TL) are carried out on the same grain. K-feldspar grains from two sediments, a marine and an alluvium, from Hong Kong were tested. Their bleaching factors indicate that bleaching of the marine sediment was not uniform, whereas the latter was relatively homogeneous. Furthermore, the relatively well-bleached grains in each sample were identified

  18. Electrical processes for the treatment of medium active liquid wastes

    Turner, A.D.; Bowen, W.R.; Bridger, N.J.; Junkinson, A.R.; Cox, D.R.

    1985-07-01

    Cross-flow electrokinetic dewatering has been developed on a lab-scale into an effective process for the treatment of such wastes as gravity-settled flocs, or sludges arising from fuel storage. The product may be concentrated to 25-42% solids while still remaining fluid, prior to immobilization - e.g. by addition of cement powder. Complete retention of activity in the concentrate was observed during the treatment of Harwell low-level waste sludges due to the high solids separation factor ( > 10 4 ). It is a low pressure, low temperature process - consuming only 0.03-0.13 kWh/L at permeation rates of 0.3-1.5 m/h (depending on the stream), corresponding to 1 /67 - 1 /15 that needed for evaporation. An advanced electrochemical ion-exchange system has been developed in which ionic material can be electrically adsorbed and eluted by polarity reversal > 1000 times, without any change in performance. Decontamination factors of about 2000 were achieved for Cs removal, up to 75% loading of the exchanger at flow rates of 8 bed volumes/h. Elution into water can give concentrates of >= 0.25 M - with consequent high volume reduction factors. Inorganic ion-exchangers have also demonstrated system selectivity for the removal of specific cations. Overall energy consumption is 3 ( 1 /400 evaporation). Significant cost savings over conventional ion-exchange may accrue from the improved performance under electrical control, and the reduced volumes of waste requiring disposal. (author)

  19. Lead corrosion evaluation in high activity nuclear waste container (Argentina)

    Guasp, R.; Lanzani, L.; Bruzzoni, P.; Cufre, W.; Semino, C.J.

    2000-01-01

    This report describes a study of high activity nuclear waste canister corrosion in a deep geological disposal. In this canister design, the vitrified nuclear waste stainless steel container is shielded by a 100 mm thick lead wall. For mechanical resistance, the canister will also have a thin carbon steel external liner. Experimental and mathematical modeling studies are aimed to asses the corrosion kinetics of the carbon steel liner in first instance and then, once this liner has been corroded away, the corrosion kinetics of the main lead barrier. Being that oxygen reduction is the main cathodic reaction that supports the anodic oxidation of iron, a model is described predicting the rate of oxygen consumption in a sealed deep nuclear waste disposal vault as a result of the canister corrosion. Oxidation processes other than container corrosion, and that can account also for oxygen depletion, are not taken into consideration. Corrosion experimental studies on lead and its alloys in groundwater are also reported. These experiments are aimed to improve the corrosion resistance of commercial lead in groundwater. (author)

  20. Temperament and perception of tooth bleaching results

    Katarzyna Mehr

    2016-09-01

    Full Text Available Background . The neurophysiological process of perceiving the results of tooth bleaching requires the correct interaction between the central nervous system and the organs of sight. Exaggerated beliefs concerning defective facial features may enhance inner attitudes about one’s own color of dentition, as well as a feeling of dissatisfaction with the degree of leaching. Objectives. The study aimed to assess the degree of the patient satisfaction with the results of tooth bleaching in relation to their temperament. Material and methods. There were 68 generally healthy volunteers, aged 28–38 years, with external discolorations of the teeth. They had never undergone dental bleaching and their frontal teeth did not have any fillings. After clinical evaluation and the completion of formalities, the patients were asked to fill in Strelau’s temperament questionnaire. Questionnaires and visual status were assessed three times by three doctors: before bleaching, and then 24 hours and two weeks after the home-bleaching operation, which was done with the use of Opalescence (Ultradent in uniform sequence. Results . There were practically no adverse side results, except a periodic dentin hypersensitivity that occurred periodically in 44 patients. The results of the visual assessment performed by the physicians did not differ. The questionnaire data showed that women were more critical of the results in relation to the expectations. Among elancholics, full satisfaction was declared by 41%, whereas among sanguine people, full satisfaction was obtained by 85%. Satisfaction with the aesthetic results was associated with bleaching by at least 4 degrees. Conclusions . Patients’ temperament affects their subjective evaluation of the effectiveness of tooth bleaching, which should be taken into consideration in the patient’s individual dental treatment plan.

  1. Bleaching and enamel surface interactions resulting from the use of highly-concentrated bleaching gels.

    Grazioli, Guillermo; Valente, Lisia Lorea; Isolan, Cristina Pereira; Pinheiro, Helena Alves; Duarte, Camila Gonçalves; Münchow, Eliseu Aldrighi

    2018-03-01

    Tooth bleaching is considered a non-invasive treatment, although the use of highly-concentrated products may provoke increased surface roughness and enamel demineralization, as well as postoperative sensitivity. Thus, the aim of this study was to investigate whether hydrogen peroxide (H 2 O 2 ) concentration would affect tooth bleaching effectiveness and the enamel surface properties. Enamel/dentin bovine specimens (6 × 4 mm) were immersed in coffee solution for 7 days and evaluated with a spectrophotometer (Easyshade; baseline), using the CIEL * a * b * color parameters. Hardness was measured using a hardness tester. The specimens were randomly assigned into four groups: one negative control, in which the specimens were not bleached, but they were irradiated with a laser-light source (Whitening Lase II, DMC Equipments); and three groups using distinct H 2 O 2 concentration, namely LP15% (15% Lase Peroxide Lite), LP25% (25% Lase Peroxide Sensy), and LP35% (35% Lase Peroxide Sensy), all products from DMC. The bleached specimens were also irradiated with the laser-light source. After bleaching, all specimens were evaluated using scanning electron microscopy (SEM). pH kinetics and rate was monitored during bleaching. The data were analyzed using ANOVA and Tukey's test (p bleaching gels produced similar color change (p > 0.05). Concerning hardness, only the LP25% and LP35% significantly reduced hardness after bleaching; also, there was a progressive tendency for a greater percentage reduction in hardness with increased H 2 O 2 concentration of the gel (R 2  = 0.9973, p bleaching effectiveness, and may increase the possibility for alteration of enamel hardness, surface morphology, and acidity of the medium. When using H 2 O 2 -based bleaching agents, dental practitioners should choose for less concentrated gels, e.g., around the 15% level. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Low activation material design methodology for reduction of radio-active wastes of nuclear power plant

    Hasegawa, A.; Satou, M.; Nogami, S.; Kakinuma, N.; Kinno, M.; Hayashi, K.

    2007-01-01

    Most of the concrete shielding walls and pipes around a reactor pressure vessel of a light water reactor become low level radioactive waste at decommission phase because they contain radioactive nuclides by thermal-neutron irradiation during its operation. The radioactivity of some low level radioactive wastes is close to the clearance level. It is very desirable in terms of life cycle cost reduction that the radioactivity of those low level radioactive wastes is decreased below clearance level. In case of light water reactors, however, methodology of low activation design of a nuclear plant has not been established yet because the reactor is a large-scale facility and has various structural materials. The Objectives of this work are to develop low activation material design methodology and material fabrication for reduction of radio-active wastes of nuclear power plant such as reinforced concrete. To realize fabrication of reduced radioactive concrete, it is necessary to develop (1) the database of the chemical composition of raw materials to select low activation materials, (2) the tool for calculation of the neutron flux and the spectrum distribution of nuclear plants to evaluate radioactivity of reactor components, (3) optimization of material process conditions to produce the low activation cement and the low activation steels. Results of the data base development, calculation tools and trial production of low activation cements will be presented. (authors)

  3. Development for low-activation concrete design reducing radioactive waste

    Kimura, Ken-ichi; Kinno, Masaharu; Hasegawa, Akira

    2008-01-01

    Full text: Concrete is very valuable and inexpensive material, however it can be changed to be expensive and hard to deal with in use of a nuclear plant after long operation. One of the counter plans for the above is to use low-activation concrete instead of the ordinary concrete, that will reduce radioactive waste and could be even below clearance level in decommissioning and that is very useful in term of life cycle cost. Radioactive analysis showed that Co and Eu were the major target elements which decide the radioactivity level of reinforced concrete in decommissioning stage, and a several material were selected as a low-activation raw material from wide survey of raw materials for concrete (typically aggregates and cements). With the canditate of raw materials, several low-activation concrete were proposed for various portion of light water reactor plant, which reduction ratio were 1/10 to 1/30 which were mainly consist of limestone and low heat cement or white cement, and 1/100 to 1/300 which were mainly consist of alumina aggregate or quartz and high almina cement, comparing to the ordinary concrete in ΣDi/Ci unit, where 'Di' indicates concentration of each residual radioisotope, Ci defined by IAEA as a clearance level, and suffition of 'i' indicates each radioisotope. National funded project for development of low-activation design method for reduction of radioactive waste below clearance level were started from 2005 with aiming (1) development of a database on the content of target elements, which transform radioactive nuclides, in raw materials of reinforced concrete, (2) development of calculation tools for estimation of residual radioactivity of plant components, and (3) development of low-activation materials for concrete such as cements and reinforcing steel bars for structural components. For the optimized design for applying low-activation concrete to the reactor portion, effective evaluation of neutron spectrum in the certain portion including

  4. Regulation of Federal radioactive waste activities. Report to Congress on extending the Nuclear Regulatory Commission's licensing or regulatory authority to Federal radioactive waste storage and disposal activities

    1979-09-01

    The report contains two recommendations for extending the Commission's regulatory authority: (1) NRC licensing authority should be extended to cover all new DOE facilities for disposal of transuranic (TRU) waste and nondefense low-level waste. (2) A pilot program, focused on a few specific DOE waste management activities, should be established to test the feasibility of extending NRC regulatory authority on a consultative basis to DOE waste management activities not now covered by NRC's licensing authority or its extension as recommended in Recommendation 1

  5. Removal of Sulfate from Waste Water by Activated Carbon

    Mohammed Sadeq Salman

    2009-01-01

    Activated carbon was Produced from coconut shell and was used for removing sulfate from industrial waste water in batch Processes. The influence of various parameter were studied such as pH (4.5 9.) , agitation time (0 120)min and adsorbent dose (2 10) gm.The Langmuir and frandlich adsorption capacity models were been investigated where showed there are fitting with langmmuir model with squre regression value ( 0.76). The percent of removal of sulfate (22% - 38%) at (PH=7) in the isotherm ...

  6. Borosilicate glasses for the high activity waste vetrification

    Cantale, C.; Donato, A.; Guidi, G.

    1984-01-01

    Some results concerning the researches carried out on the high-level wastes vitrification at ENEA, Comb-Mepis-Rifiu laboratory are reported. A fission product solution referred to power plant nuclear fuel reprocessing has been selected and simulated with no radioactive chemicals. Some glass composition have been tested for the vitrification of this solution, the best of them being taken into consideration for real active tests at the hot bench scale plant ESTER in Ispra. The final glasses have been characterized from the chemical and physical point of view; moreover some microstructural investigations have been performed in order to identify few microsegregations and to test the degree of amorphousness of the products

  7. Automation of a measurement systems of waste drum alpha activity

    Labarre, S.; Bardy, N.

    1985-10-01

    The alpha radiator activity in the two-hundred liter waste drums is found by an IN96, computerized analyzer of the society Intertechnique, from data delivered by a gamma detector (GeHP) and by neutron detection blocks (He counter). This computerized analyzer manages not only the drum rotation and position in front of the detector, but also the experimental data monitoring and their processing from specific programs (background noise, calibration, drum measurements). Thanks to this automation, the measurement number and their reliability are optimized [fr

  8. Electrochemical ion-exchange for active liquid waste treatment

    Turner, A.D.; Bridger, N.J.; Jones, C.P.

    1992-10-01

    Electrochemical ion exchange (EIX) has been firmly established as an effective process for the treatment of a wide range of liquid radioactive wastes. Both organic (for low specific activity streams) and inorganic systems (for higher activity wastes) have been demonstrated. A low cost current feeder electrode has also been developed, with a projected lifetime of > 6 years. While cation EIX can be used for the treatment of low salt content streams, combination with anion EIX to control the pH can extend its range of application. At the same time, it is also able to remove activity complexed in an anionic form. AEIX has also demonstrated its ability to remove radionuclides with insoluble hydroxides (eg Co, U and Pu) from both high and low salt content streams. EIX has been successfully scaled-up form the bench-top scale by increasing electrode size by a factor of 11, and then by operating five units in parallel. An improvement in performance of by a factor 3 was observed over a simple increase in area, due to the minimization of edge effects in the larger units. The most significant advantage of EIX is its compactness -with plant sizes of 1000). (Author)

  9. Unprecedented Mass Bleaching and Loss of Coral across 12° of Latitude in Western Australia in 2010–11

    Moore, James A. Y.; Bellchambers, Lynda M.; Depczynski, Martial R.; Evans, Richard D.; Evans, Scott N.; Field, Stuart N.; Friedman, Kim J.; Gilmour, James P.; Holmes, Thomas H.; Middlebrook, Rachael; Radford, Ben T.; Ridgway, Tyrone; Shedrawi, George; Taylor, Heather; Thomson, Damian P.; Wilson, Shaun K.

    2012-01-01

    Background Globally, coral bleaching has been responsible for a significant decline in both coral cover and diversity over the past two decades. During the summer of 2010–11, anomalous large-scale ocean warming induced unprecedented levels of coral bleaching accompanied by substantial storminess across more than 12° of latitude and 1200 kilometers of coastline in Western Australia (WA). Methodology/Principal Findings Extreme La-Niña conditions caused extensive warming of waters and drove considerable storminess and cyclonic activity across WA from October 2010 to May 2011. Satellite-derived sea surface temperature measurements recorded anomalies of up to 5°C above long-term averages. Benthic surveys quantified the extent of bleaching at 10 locations across four regions from tropical to temperate waters. Bleaching was recorded in all locations across regions and ranged between 17% (±5.5) in the temperate Perth region, to 95% (±3.5) in the Exmouth Gulf of the tropical Ningaloo region. Coincident with high levels of bleaching, three cyclones passed in close proximity to study locations around the time of peak temperatures. Follow-up surveys revealed spatial heterogeneity in coral cover change with four of ten locations recording significant loss of coral cover. Relative decreases ranged between 22%–83.9% of total coral cover, with the greatest losses in the Exmouth Gulf. Conclusions/Significance The anomalous thermal stress of 2010–11 induced mass bleaching of corals along central and southern WA coral reefs. Significant coral bleaching was observed at multiple locations across the tropical-temperate divide spanning more than 1200 km of coastline. Resultant spatially patchy loss of coral cover under widespread and high levels of bleaching and cyclonic activity, suggests a degree of resilience for WA coral communities. However, the spatial extent of bleaching casts some doubt over hypotheses suggesting that future impacts to coral reefs under forecast

  10. Unprecedented mass bleaching and loss of coral across 12° of latitude in Western Australia in 2010-11.

    Moore, James A Y; Bellchambers, Lynda M; Depczynski, Martial R; Evans, Richard D; Evans, Scott N; Field, Stuart N; Friedman, Kim J; Gilmour, James P; Holmes, Thomas H; Middlebrook, Rachael; Radford, Ben T; Ridgway, Tyrone; Shedrawi, George; Taylor, Heather; Thomson, Damian P; Wilson, Shaun K

    2012-01-01

    Globally, coral bleaching has been responsible for a significant decline in both coral cover and diversity over the past two decades. During the summer of 2010-11, anomalous large-scale ocean warming induced unprecedented levels of coral bleaching accompanied by substantial storminess across more than 12° of latitude and 1200 kilometers of coastline in Western Australia (WA). Extreme La-Niña conditions caused extensive warming of waters and drove considerable storminess and cyclonic activity across WA from October 2010 to May 2011. Satellite-derived sea surface temperature measurements recorded anomalies of up to 5°C above long-term averages. Benthic surveys quantified the extent of bleaching at 10 locations across four regions from tropical to temperate waters. Bleaching was recorded in all locations across regions and ranged between 17% (±5.5) in the temperate Perth region, to 95% (±3.5) in the Exmouth Gulf of the tropical Ningaloo region. Coincident with high levels of bleaching, three cyclones passed in close proximity to study locations around the time of peak temperatures. Follow-up surveys revealed spatial heterogeneity in coral cover change with four of ten locations recording significant loss of coral cover. Relative decreases ranged between 22%-83.9% of total coral cover, with the greatest losses in the Exmouth Gulf. The anomalous thermal stress of 2010-11 induced mass bleaching of corals along central and southern WA coral reefs. Significant coral bleaching was observed at multiple locations across the tropical-temperate divide spanning more than 1200 km of coastline. Resultant spatially patchy loss of coral cover under widespread and high levels of bleaching and cyclonic activity, suggests a degree of resilience for WA coral communities. However, the spatial extent of bleaching casts some doubt over hypotheses suggesting that future impacts to coral reefs under forecast warming regimes may in part be mitigated by southern thermal refugia.

  11. The northern limit of corals of the genus Acropora in temperate zones is determined by their resilience to cold bleaching.

    Higuchi, Tomihiko; Agostini, Sylvain; Casareto, Beatriz Estela; Suzuki, Yoshimi; Yuyama, Ikuko

    2015-12-18

    The distribution of corals in Japan covers a wide range of latitudes, encompassing tropical to temperate zones. However, coral communities in temperate zones contain only a small subset of species. Among the parameters that determine the distribution of corals, temperature plays an important role. We tested the resilience to cold stress of three coral species belonging to the genus Acropora in incubation experiments. Acropora pruinosa, which is the northernmost of the three species, bleached at 13 °C, but recovered once temperatures were increased. The two other species, A. hyacinthus and A. solitaryensis, which has a more southerly range than A. pruinosa, died rapidly after bleaching at 13 °C. The physiological effects of cold bleaching on the corals included decreased rates of photosynthesis, respiration, and calcification, similar to the physiological effects observed with bleaching due to high temperature stress. Contrasting hot bleaching, no increases in antioxidant enzyme activities were observed, suggesting that reactive oxygen species play a less important role in bleaching under cold stress. These results confirmed the importance of resilience to cold stress in determining the distribution and northern limits of coral species, as cold events causing coral bleaching and high mortality occur regularly in temperate zones.

  12. Effect of Toothpaste Application Prior to Dental Bleaching on Whitening Effectiveness and Enamel Properties.

    Vieira-Junior, W F; Lima, D A N L; Tabchoury, C P M; Ambrosano, G M B; Aguiar, F H B; Lovadino, J R

    2016-01-01

    The purpose of this study was to investigate the effects on the enamel properties and effectiveness of bleaching using 35% hydrogen peroxide (HP) when applying toothpastes with different active agents prior to dental bleaching. Seventy enamel blocks (4 × 4 × 2 mm) were submitted to in vitro treatment protocols in a tooth-brushing machine (n=10): with distilled water and exposure to placebo gel (negative control [NC]) or HP bleaching (positive control [PC]); and brushing with differing toothpastes prior to HP bleaching, including potassium nitrate toothpaste (PN) containing NaF, conventional sodium monofluorophosphate toothpaste (FT), arginine-based toothpastes (PA and SAN), or a toothpaste containing bioactive glass (NM). Color changes were determined using the CIE L*a*b* system (ΔE, ΔL, Δa, and Δb), and a roughness (Ra) analysis was performed before and after treatments. Surface microhardness (SMH) and cross-sectional microhardness (CSMH) were analyzed after treatment. Data were analyzed with repeated measures ANOVA for Ra, one-way ANOVA (SMH, ΔE, ΔL, Δa, and Δb), split-plot ANOVA (CSMH), and Tukey post hoc test (α PA = SAN > all other groups) or decreased HP effects (CSMH). Ra increased in all bleached groups, with the exception of NM, which did not differ from the NC. The variation in the color variables (ΔL, Δa, and Δb) explained 21% of the variation in the physical surface variables (Ra and SMH). The application of toothpaste prior to dental bleaching did not interfere with the effectiveness of treatment. The bioactive glass based toothpaste protected the enamel against the deleterious effects of dental bleaching.

  13. Short communication: The influence of solids concentration and bleaching agent on bleaching efficacy and flavor of sweet whey powder.

    Jervis, M G; Smith, T J; Drake, M A

    2015-04-01

    Recent studies have demonstrated the effect of bleaching conditions and bleaching agent on flavor and functional properties of whey protein ingredients. Solids concentration at bleaching significantly affected bleaching efficacy and flavor effects of different bleaching agents. It is not known if these parameters influence quality of sweet whey powder (SWP). The purpose of this study was to determine the effects of solids concentration and bleaching agent on the flavor and bleaching efficacy of SWP. Colored cheddar whey was manufactured, fat separated, and pasteurized. Subsequently, the whey (6.7% solids) was bleached, concentrated using reverse osmosis (RO) to 14% solids, and then spray dried, or whey was concentrated before bleaching and then spray dried. Bleaching treatments included a control (no bleaching, 50 °C, 60 min), hydrogen peroxide (HP; 250 mg/kg, 50 °C, 60 min), benzoyl peroxide (50 mg/kg, 50 °C, 60 min), lactoperoxidase (20 mg/kg of HP, 50 °C, 30 min), and external peroxidase (MaxiBright, DSM Food Specialties, Delft, the Netherlands; 2 dairy bleaching units/mL, 50 °C, 30 min). The experiment was repeated in triplicate. Sensory properties and volatile compounds of SWP were evaluated by a trained panel and gas chromatography-mass spectrometry, respectively. Bleaching efficacy (norbixin destruction) and benzoic acid were measured by HPLC. Differences in bleaching efficacy, sensory and volatile compound profiles, and benzoic acid were observed with different bleaching agents, consistent with previous studies. Solids concentration affected bleaching efficacy of HP, but not other bleaching agents. The SWP from whey bleached with HP or lactoperoxidase following RO had increased cardboard and fatty flavors and higher concentrations of lipid oxidation compounds compared with SWP from whey bleached before RO. The SWP bleached with benzoyl peroxide after RO contained less benzoic acid than SWP from whey bleached before RO. These results indicate that

  14. Maxey Flats low-level waste disposal site closure activities

    Haight, C.P.; Mills, D.; Razor, J.E.

    1987-01-01

    The Maxey Flats Radioactive Waste Disposal Facility in Fleming County, Kentucky is in the process of being closed. The facility opened for commercial business in the spring of 1963 and received approximately 4.75 million cubic feet of radioactive waste by the time it was closed in December of 1977. During fourteen years of operation approximately 2.5 million curies of by-product material, 240,000 kilograms of source material, and 430 kilograms of special nuclear material were disposed. The Commonwealth purchased the lease hold estate and rights in May 1978 from the operating company. This action was taken to stabilize the facility and prepare it for closure consisting of passive care and monitoring. To prepare the site for closure, a number of remedial activities had to be performed. The remediation activities implemented have included erosion control, surface drainage modifications, installation of a temporary plastic surface cover, leachate removal, analysis, treatment and evaporation, US DOE funded evaporator concentrates solidification project and their on-site disposal in an improved disposal trench with enhanced cover for use in a humid environment situated in a fractured geology, performance evaluation of a grout injection demonstration, USGS subsurface geologic investigation, development of conceptual closure designs, and finally being added to the US EPA National Priority List for remediation and closure under Superfund. 13 references, 3 figures

  15. Melter feed viscosity during conversion to glass: Comparison between low-activity waste and high-level waste feeds

    Jin, Tongan [Pacific Northwest National Laboratory, Richland Washington; Chun, Jaehun [Pacific Northwest National Laboratory, Richland Washington; Dixon, Derek R. [Pacific Northwest National Laboratory, Richland Washington; Kim, Dongsang [Pacific Northwest National Laboratory, Richland Washington; Crum, Jarrod V. [Pacific Northwest National Laboratory, Richland Washington; Bonham, Charles C. [Pacific Northwest National Laboratory, Richland Washington; VanderVeer, Bradley J. [Pacific Northwest National Laboratory, Richland Washington; Rodriguez, Carmen P. [Pacific Northwest National Laboratory, Richland Washington; Weese, Brigitte L. [Pacific Northwest National Laboratory, Richland Washington; Schweiger, Michael J. [Pacific Northwest National Laboratory, Richland Washington; Kruger, Albert A. [U.S. Department of Energy, Office of River Protection, Richland Washington; Hrma, Pavel [Pacific Northwest National Laboratory, Richland Washington

    2017-12-07

    During nuclear waste vitrification, a melter feed (generally a slurry-like mixture of a nuclear waste and various glass forming and modifying additives) is charged into the melter where undissolved refractory constituents are suspended together with evolved gas bubbles from complex reactions. Knowledge of flow properties of various reacting melter feeds is necessary to understand their unique feed-to-glass conversion processes occurring within a floating layer of melter feed called a cold cap. The viscosity of two low-activity waste (LAW) melter feeds were studied during heating and correlated with volume fractions of undissolved solid phase and gas phase. In contrast to the high-level waste (HLW) melter feed, the effects of undissolved solid and gas phases play comparable roles and are required to represent the viscosity of LAW melter feeds. This study can help bring physical insights to feed viscosity of reacting melter feeds with different compositions and foaming behavior in nuclear waste vitrification.

  16. 75 FR 65625 - Agency Information Collection Activities; Proposed Collection; Comment Request; Hazardous Waste...

    2010-10-26

    ... Activities; Proposed Collection; Comment Request; Hazardous Waste Specific Unit Requirements, and Special Waste Processes and Types, EPA ICR Number 1572.08, OMB Control Number 2050-0050 AGENCY: Environmental..., and Special Waste Processes and Types. ICR numbers: EPA ICR No. 1572.08, OMB Control No. 2050-0050...

  17. Los Alamos Scientific Laboratory waste management technology development activities. Summary progress report, 1979

    Johnson, L.J.

    1980-10-01

    Summary reports on the Department of Energy's Nuclear Energy-sponsored waste management technology development projects at the Los Alamos Scientific Laboratory describe progress for calendar year 1979. Activities in airborne, low-level, and transuranic waste management areas are discussed. Work progress on waste assay, treatment, disposal, and environmental monitoring is reviewed

  18. Los Alamos Scientific Laboratory waste management technology development activities. Summary progress report, 1979

    Johnson, L.J. (comp.)

    1980-10-01

    Summary reports on the Department of Energy's Nuclear Energy-sponsored waste management technology development projects at the Los Alamos Scientific Laboratory describe progress for calendar year 1979. Activities in airborne, low-level, and transuranic waste management areas are discussed. Work progress on waste assay, treatment, disposal, and environmental monitoring is reviewed.

  19. Scenarios for the Hanford Immobilized Low-Activity Waste (ILAW) performance assessment

    MANN, F.M.

    1999-01-01

    Scenarios describing representative exposure cases associated with the disposal of low activity waste from the Hanford Waste Tanks have been defined. These scenarios are based on guidance from the Department of Energy, the U.S. Nuclear Regulatory Commission, and previous Hanford waste disposal performance assessments

  20. Performance objectives for the Hanford Immobilized Low-Activity Waste (ILAW) performance assessment

    MANN, F.M.

    1999-01-01

    Performance objectives for the disposal of low activity waste from Hanford Waste Tanks have been developed. These objectives have been based on DOE requirements, programmatic requirements, and public involvement. The DOE requirements include regulations that direct the performance assessment and are cited within the Radioactive Waste Management Order (DOE Order 435.1). Performance objectives for other DOE complex performance assessments have been included

  1. Improvement in dry active waste segregation and processing

    Hillmer, T.P.; Anderson, K.D.; Dahlen, D.E.

    1989-01-01

    At the Palo Verde Nuclear Generating Station (PVNGS) the majority of dry active waste (DAW) volume reduction activities are performed in the site's new DAW processing and storage facility. This facility houses an interim storage area for a five year volume of compacted DAW, a shredder/compactor, and a DAW segregation area. The DAW segregation program locates and separates non-radioactive and reusable materials from DAW generated at the three unit PVNGS site. This program has saved more than 24,000 cubic feet of burial space and has reclaimed more than $1,000,000 worth of materials. Palo Verde has made numerous changes to the DAW segregation program since its inception. To ensure that the DAW segregation program remained cost effective and in compliance with applicable regulatory guidance, segregation techniques were revised and new equipment was evaluated and procured. This paper details that effort and summarizes the operational data that has been collected

  2. Waste Management Policy Framework to Mitigate Terrorist Intrusion Activities

    Redus, Kenneth S.

    2003-01-01

    A policy-directed framework is developed to support US Department of Energy (DOE) counterterrorism efforts, specifically terrorist intrusion activities that affect of Environmental Management (EM) programs. The framework is called the Security Effectiveness and Resource Allocation Definition Forecasting and Control System (SERAD-FACS). Use of SERAD-FACS allows trade-offs between resources, technologies, risk, and Research and Development (R and D) efforts to mitigate such intrusion attempts. Core to SERAD-FACS is (1) the understanding the perspectives and time horizons of key decisionmakers and organizations, (2) a determination of site vulnerabilities and accessibilities, and (3) quantifying the measures that describe the risk associated with a compromise of EM assets. The innovative utility of SERAD-FACS is illustrated for three integrated waste management and security strategies. EM program risks, time delays, and security for effectiveness are examined to demonstrate the significant cost and schedule impact terrorist activities can have on cleanup efforts in the DOE complex

  3. High active waste (HAW) data report January-June 1991

    Duijves, K.A.

    1992-04-01

    Data are presented from the High Active Waste (HAW) experiment, a large-scale, in situ test being performed underground at the Asse salt mine in Remlingen, FRG. These data include selected field information, the test configuration, instrumentation activities and comprehensive results from a large number of gauges. The results are measured data obtained from gap meters, thermocouples, linear displacement transducers, extensometers, inclinometers and pressure gauges. Data certification practices have been described together with the quality assurance of the data reduction and of the data base management system. The experiment began on November 8, 1988 and will continue for five years. Data in this report cover the period from January 1st, 1991 to June 30, 1991. (author). 4 refs.; 43 figs.; 8 tabs

  4. Local stressors reduce coral resilience to bleaching.

    Carilli, Jessica E; Norris, Richard D; Black, Bryan A; Walsh, Sheila M; McField, Melanie

    2009-07-22

    Coral bleaching, during which corals lose their symbiotic dinoflagellates, typically corresponds with periods of intense heat stress, and appears to be increasing in frequency and geographic extent as the climate warms. A fundamental question in coral reef ecology is whether chronic local stress reduces coral resistance and resilience from episodic stress such as bleaching, or alternatively promotes acclimatization, potentially increasing resistance and resilience. Here we show that following a major bleaching event, Montastraea faveolata coral growth rates at sites with higher local anthropogenic stressors remained suppressed for at least 8 years, while coral growth rates at sites with lower stress recovered in 2-3 years. Instead of promoting acclimatization, our data indicate that background stress reduces coral fitness and resilience to episodic events. We also suggest that reducing chronic stress through local coral reef management efforts may increase coral resilience to global climate change.

  5. On luminescence bleaching of tidal channel sediments

    Fruergaard, Mikkel; Pejrup, Morten; Murray, Andrew S.

    2015-01-01

    We investigate the processes responsible for bleaching of the quartz OSL signal from tidal channel sediment. Tidal dynamics are expected to play an important role for complete bleaching of tidal sediments. However, no studies have examined the amount of reworking occurring in tidal channels...... and on tidal flats due to the mixing caused by currents and waves. We apply bed level data to evaluate the amount of vertical sediment reworking in modern tidal channels and at a tidal flat. Cycles of deposition and erosion are measured with a bed level sensor, and the results show that gross sedimentation...... was several times higher than net sedimentation. We propose that tidal channel sediment is bleached either on the tidal flat before it is transported to the tidal channels and incorporated in channel-fill successions or, alternatively, on the shallow intertidal part of the channel banks. Based...

  6. Winery waste recycling through anaerobic co-digestion with waste activated sludge.

    Da Ros, C; Cavinato, C; Pavan, P; Bolzonella, D

    2014-11-01

    In this study biogas and high quality digestate were recovered from winery waste (wine lees) through anaerobic co-digestion with waste activated sludge both in mesophilic and thermophilic conditions. The two conditions studied showed similar yields (0.40 m(3)/kgCODfed) but different biological process stability: in fact the mesophilic process was clearly more stable than the thermophilic one in terms of bioprocess parameters. The resulting digestates showed good characteristics for both the tested conditions: heavy metals, dioxins (PCDD/F), and dioxin like bi-phenyls (PCBs) were concentred in the effluent if compared with the influent because of the important reduction of the solid dry matter, but remained at levels acceptable for agricultural reuse. Pathogens in digestate decreased. Best reductions were observed in thermophilic condition, while at 37°C the concentration of Escherichia coli was at concentrations level as high as 1000 UFC/g. Dewatering properties of digestates were evaluated by means of the capillary suction time (CST) and specific resistance to filtration (SRF) tests and it was found that a good dewatering level was achievable only when high doses of polymer (more than 25 g per kg dry solids) were added to sludge. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Demonstration of sulfur solubility determinations in high waste loading, low-activity waste glasses

    Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-04-25

    A method recommended by Pacific Northwest National Laboratory (PNNL) for sulfate solubility determinations in simulated low-activity waste glasses was demonstrated using three compositions from a recent Hanford high waste loading glass study. Sodium and sulfate concentrations in the glasses increased after each re-melting step. Visual observations of the glasses during the re-melting process reflected the changes in composition. The measured compositions showed that the glasses met the targeted values. The amount of SO3 retained in the glasses after washing was relatively high, ranging from 1.6 to 2.6 weight percent (wt %). Measured SnO2 concentrations were notably low in all of the study glasses. The composition of the wash solutions should be measured in future work to determine whether SnO2 is present with the excess sulfate washed from the glass. Increases in batch size and the amount of sodium sulfate added did not have a measureable impact on the amount of sulfate retained in the glass, although this was tested for only a single glass composition. A batch size of 250 g and a sodium sulfate addition targeting 7 wt %, as recommended by PNNL, will be used in future experiments.

  8. Evaporation Of Hanford Waste Treatment Plant Direct Feed Low Activity Waste Effluent Management Facility Core Simulant

    Adamson, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Mcclane, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-01

    The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Melter Off-Gas Condensate, LMOGC) from the off-gas system. The baseline plan for disposition of this stream during full WTP operations is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation, and recycled to the LAW vitrification facility. However, during the Direct Feed LAW (DFLAW) scenario, planned disposition of this stream is to evaporate it in a new evaporator, in the Effluent Management Facility (EMF), and then return it to the LAW melter. It is important to understand the composition of the effluents from the melter and new evaporator, so that the disposition of these streams can be accurately planned and accommodated. Furthermore, alternate disposition of the LMOGC stream would eliminate recycling of problematic components, and would reduce the need for closely integrated operation of the LAW melter and the Pretreatment Facilities. Long-term implementation of this option after WTP start-up would decrease the LAW vitrification mission duration and quantity of glass waste, amongst the other operational complexities such a recycle stream presents. In order to accurately plan for the disposition path, it is key to experimentally determine the fate of contaminants. To do this, testing is needed to accurately account for the buffering chemistry of the components, determine the achievable evaporation end point, identify insoluble solids that form, and determine the distribution of key regulatory-impacting constituents. The LAW Melter Off-Gas Condensate stream will contain components that are volatile at melter temperatures, have limited solubility in the glass waste form, and represent a materials corrosion concern, such as halides and sulfate. Because this stream will recycle within WTP, these components will accumulate in the Melter Condensate

  9. Effects of bleaching wastewater irrigation on soil quality of constructed reed wetlands

    Cheng Ding

    2016-10-01

    Full Text Available Constructed reed wetland microcosms (CRWs in a lab of east China have been irrigated with bleaching wastewater per month for a reed growth season. The soil physicochemical properties, enzyme activities (i.e. urease, invertase, polyphenol oxidase, alkaline phosphatase and cellulase and soil microbial diversity were assayed before and after the exposure experiment. Compared to the river water irrigated controls (CKs, bleaching wastewater application has no marked influence on soil pH, but significantly increased soil Na+, total halogen and absorbable organic halogen (AOX contents, which induced the increasing of soil electrical conductivity. Furthermore, soil enzyme activities displayed significant variation (except for polyphenol oxidase. Bleaching wastewater irrigation decreased Sorenson’s pairwise similarity coefficient (Cs, which indicated the changes of the structure of bacterial and fungal communities. However, only the diversity of bacterial community was inhibited and has no effect on the diversity of fungal community, as evidenced by the calculated Shannon–Wiener index (H.

  10. Coral Bleaching and Associated Mortality at Mayotte, Western Indian ...

    Mamoudzou 97600, Mayotte. Keywords: coral, bleaching, mortality, Mayotte, Western Indian Ocean. Abstract—Bleaching and associated coral mortality were assessed on fringing and barrier reefs on the north and east coasts of Mayotte from 1-24 May 2010. Major bleaching was encountered; nearly 80% of the corals were ...

  11. Mass coral bleaching in the northern Persian Gulf, 2012

    Javid Kavousi

    2014-09-01

    Full Text Available Coral bleaching events due to elevated temperatures are increasing in both frequency and magnitude worldwide. Mass bleaching was recorded at five sites in the northern Persian Gulf during August and September 2012. Based on available seawater temperature data from field, satellite and previous studies, we suggest that the coral bleaching threshold temperature in the northern Persian Gulf is between 33.5 and 34°C, which is about 1.5 to 2.5°C lower than that in the southern part. To assess the bleaching effects, coral genera counted during 60-minute dives were categorized into four groups including healthy, slightly bleached ( 50% bleached tissue and fully bleached colonies. The anomalously high sea surface temperature resulted in massive coral bleaching (~84% coral colonies affected. Acropora spp. colonies, which are known as the most vulnerable corals to thermal stress, were less affected by the bleaching than massive corals, such as Porites, which are among the most thermo-tolerant corals. Turbid waters, suggested as coral refugia against global warming, did not protect corals in this study since most affected corals were found in the most turbid waters. The 2012 bleaching in the northern Persian Gulf was relatively strong from the viewpoint of coral bleaching severity. Long-term monitoring is needed to understand the actual consequences of the bleaching event on the coral reefs and communities.

  12. 21 CFR 872.6475 - Heat source for bleaching teeth.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Heat source for bleaching teeth. 872.6475 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device that consists of a...

  13. Bleaching and diffusion dynamics in optofluidic dye lasers

    Gersborg-Hansen, Morten; Balslev, Søren; Mortensen, Asger

    2007-01-01

    The authors have investigated the bleaching dynamics that occur in optofluidic dye lasers where the liquid laser dye in a microfluidic channel is locally bleached due to optical pumping. They find that for microfluidic devices, the dye bleaching may be compensated through diffusion of dye molecules...

  14. Tooth Bleaching: Current Concepts of the Procedure in Cosmetic ...

    Less caustic agents more recently introduced, in the late 1900s, have revived the interest of the dental profession in the art of tooth bleaching. These agents are now being packaged as bleaching kits, which may be used for in-office bleaching by the dentist or used at home by the patient under the supervision of the dentist.

  15. Development of acceptance specifications for low-activity waste from the Hanford tanks

    Cunnane, J.C.; Kier, P.H.; Brown, N.R.

    1997-01-01

    Low-activity products will be in the form of soldified waste and optional matrix and filler materials enclosed in sealed metal boxes. Acceptance specifications limit the physical characteristics of the containers, the chemical and physical characteristics of the waste form and other materials that may be in the container, the waste loading, and the radionuclide leaching characteristics of the waste form. The specifications are designed to ensure that low-activity waste products will be compatible with the driving regulatory and operational requirements and with existing production technologies

  16. The Japan Power Demonstration Reactor (JPDR) dismantling activities. Management of JPDR dismantling waste

    Abe, Masayoshi; Nakata, Susumu; Ito, Shinichi

    1996-01-01

    The management of wastes, both radioactive and non-radioactive, is one of the most important issues for a safe and reasonable dismantling operation of nuclear power plants. A large amount of radioactive wastes is arising from a reactor dismantling operation in a relatively short period time, ranging in a wide variety from very low level to relatively high level. Moreover non-radioactive waste is also in a huge amount. The dismantling operation of Japan Power Demonstration Reactor (JPDR) resulted in 24,440 tons of dismantling wastes, of which about 15% was radioactive and 85% non-radioactive. These wastes were managed successfully implementing a well developed management plan for JPDR dismantling waste. Research and development works for handling of JPDR dismantling wastes were performed, including fixation of loose contamination on surface, volume reduction and waste containers for on-site transportation and interim storage. The JPDR dismantling wastes generated were classified and categorized depending on their materials, characteristics and activity level. Approximately 2,100 tons of radioactive wastes were stored in the interim storage facilities on site using developed containers, and 1,670 tons of radioactive concrete waste were used for a safe demonstration test of a simple near-surface disposal for very low level waste. Other dismantling wastes such as steel and concrete which were categorized as non-radioactive were recycled and reused as useful resources. This paper describes the management of the JPDR dismantling wastes. (author)

  17. Laboratory optimization tests of technetium decontamination of Hanford Waste Treatment Plant low activity waste melter off-gas condensate simulant

    Taylor-Pashow, Kathryn M.L. [Savannah River Site (SRS), Aiken, SC (United States); McCabe, Daniel J. [Savannah River Site (SRS), Aiken, SC (United States)

    2015-11-01

    The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Off-Gas Condensate) from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable simplified operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also decrease the LAW vitrification mission duration and quantity of glass waste.

  18. Categorisation of waste streams arising from the operation of a low active waste incinerator and justification of discharge practices

    Richards, J.M.

    1989-01-01

    Waste streams arising from the low active waste incinerator at Harwell are described, and the radiological impact of each exposure pathway discussed. The waste streams to be considered are: (i) discharge of scrubber liquors after effluent treatment to the river Thames; (ii) disposal of incinerator ash; and (iii) discharge of airborne gaseous effluents to the atmosphere. Doses to the collective population and critical groups as a result of the operation of the incinerator are assessed and an attempt made to justify the incineration practice by consideration of the radiological impact and monetary costs associated with alternative disposal methods. (author)

  19. Anaerobic co-digestion of winery waste and waste activated sludge: assessment of process feasibility.

    Da Ros, C; Cavinato, C; Cecchi, F; Bolzonella, D

    2014-01-01

    In this study the anaerobic co-digestion of wine lees together with waste activated sludge in mesophilic and thermophilic conditions was tested at pilot scale. Three organic loading rates (OLRs 2.8, 3.3 and 4.5 kgCOD/m(3)d) and hydraulic retention times (HRTs 21, 19 and 16 days) were applied to the reactors, in order to evaluate the best operational conditions for the maximization of the biogas yields. The addition of lee to sludge determined a higher biogas production: the best yield obtained was 0.40 Nm(3)biogas/kgCODfed. Because of the high presence of soluble chemical oxygen demand (COD) and polyphenols in wine lees, the best results in terms of yields and process stability were obtained when applying the lowest of the three organic loading rates tested together with mesophilic conditions.

  20. Radioisotope Characterization of HB Line Low Activity Waste

    Snyder, S.J.

    1999-01-01

    The purpose of this document is to provide a physical, chemical, hazardous and radiological characterization of Low-Level Waste (LLW) generated in HB-Line as required by the 1S Manual, Savannah River Site Waste Acceptance Criteria Manual

  1. Current activities in DOE's commercial waste management program

    1978-03-01

    Deep geologic disposal of radioactive wastes is being studied. Packaging and storage of spent fuel are also considered. Potential sites at Hanford and NTS are discussed. Research on waste immobilization and supporting studies is reported

  2. Influence of whitening gel on pulp chamber temperature rise by in-office bleaching technique

    Sandro Cordeiro Loretto

    Full Text Available INTRODUCTION: Dental bleaching is a conservative method for the aesthetic restoration of stained teeth. However, whitening treatments are likely to cause adverse effects when not well planned and executed. OBJECTIVE: This study evaluated the influence of whitening gel on temperature rise in the pulp chamber, using the in-office photoactivated dental bleaching technique. MATERIAL AND METHOD: The root portion of an upper central human incisor was sectioned 3mm below the cemento-enamel junction. The root canal was enlarged to permit the insertion of the K-type thermocouple sensor (MT-401 into the pulp chamber, which was filled with thermal paste to facilitate the transfer of heat during bleaching. Three photosensitive whitening agents (35% hydrogen peroxide were used: Whiteness HP (FGM, Whiteness HP Maxx (FGM and Lase Peroxide Sensy (DMC. An LED photocuring light (Flash Lite - Discus Dental was used to activate the whitening gels. Six bleaching cycles were performed on each group tested. The results were submitted to one-way ANOVA and LSD t-test (α<0.05. RESULT: The lowest mean temperature variation (ºC was detected for Lase Peroxide Sensy (0.20, while the highest was recorded for Whiteness HP (1.50. CONCLUSION: The Whiteness HP and Whiteness HP Maxx whitening gels significantly affected the temperature rise in the pulp chamber during bleaching, and this variation was dependent on the type of whitening gel used.

  3. Variables and potential models for the bleaching of luminescence signals in fluvial environments

    Gray, Harrison J.; Mahan, Shannon

    2015-01-01

    Luminescence dating of fluvial sediments rests on the assumption that sufficient sunlight is available to remove a previously obtained signal in a process deemed bleaching. However, luminescence signals obtained from sediment in the active channels of rivers often contain residual signals. This paper explores and attempts to build theoretical models for the bleaching of luminescence signals in fluvial settings. We present two models, one for sediment transported in an episodic manner, such as flood-driven washes in arid environments, and one for sediment transported in a continuous manner, such as in large continental scale rivers. The episodic flow model assumes that the majority of sediment is bleached while exposed to sunlight at the near surface between flood events and predicts a power-law decay in luminescence signal with downstream transport distance. The continuous flow model is developed by combining the Beer–Lambert law for the attenuation of light through a water column with a general-order kinetics equation to produce an equation with the form of a double negative exponential. The inflection point of this equation is compared with the sediment concentration from a Rouse profile to derive a non-dimensional number capable of assessing the likely extent of bleaching for a given set of luminescence and fluvial parameters. Although these models are theoretically based and not yet necessarily applicable to real-world fluvial systems, we introduce these ideas to stimulate discussion and encourage the development of comprehensive bleaching models with predictive power.

  4. Radiation effects on medium active waste forms. Annual report - 1988

    Johnson, D.; Wilding, C.; Lyon, C.

    1989-01-01

    and such measurements can now be performed on a routine basis. More work is however required to obtain reliable data for cement systems which are completely saturated with water. γ irradiation has started on a waste form simulate of RMA11.1 which more closely resembles the real waste form. The waste material is enclosed in a steel mesh basket which is totally encased in cement grout. Samples of fully active dissolver residues have been obtained from the dissolver of the fast reactor reprocessing plant at Dounreay and transported to Harwell. The fuel hull samples were from fuels that had achieved 8 and 16% burn-up in PFR. Characterisation analyses have begun at Dounreay and Harwell prior to the preparation of immobilised samples at Harwell. (author)

  5. Safety research activities on radioactive waste management in JNES

    Otsuka, Ichiro; Aoki, Hiroomi; Suko, Takeshi; Onishi, Yuko; Masuda, Yusuke; Kato, Masami

    2010-01-01

    Research activities in safety regulation of radioactive waste management are presented. Major activities are as follows. As for the geological disposal, major research areas are, developing 'safety indicators' to judge the adequacy of site investigation results presented by an implementer (NUMO), compiling basic requirements of safety design and safety assessment needed to make a safety review of the license application and developing an independent safety assessment methodology. In proceeding research, JNES, Japan Atomic Energy Agency (JAEA) and the National Institute of Advanced Industrial Science and Technology (AIST) signed an agreement of cooperative study on geological disposal in 2007. One of the ongoing joint studies under this agreement has been aimed at investigating regional-scale hydrogeological modeling using JAEA's Horonobe Underground Research Center. In the intermediate depth disposal, JNES conducted example analysis of reference facility and submitted the result to Nuclear Safety Commission of Japan (NSC). JNES is also listing issues to be addressed in the safety review of the license application and tries to make criteria of the review. Furthermore, JNES is developing analysis tool to evaluate long term safety of the facility and conducting an experiment to investigate long term behavior of engineered barrier system. In the near surface disposal of waste package, it must be confirmed by a regulatory inspector whether each package meets safety requirements. JNES continuously updates the confirmation methodology depending on new processing technologies. The clearance system was established in 2005. Two stages of regulatory involvement were adapted, 1) approval for measurement and judgment methods developed by the nuclear operator and 2) confirmation of measurement and judgment results based on approved methods. JNES is developing verification methodology for each stage. As for decommissioning, based on the regulatory needs and a research program

  6. The IAEA's activities in the field of radioactive waste management

    Semenov, B.A.

    1984-01-01

    The IAEA has been concerned with radioactive waste management since its inception. Its programme in this area was expanded in the mid 1970s as questions related to the management and disposal of radioactive wastes came into focus in conjunction with the further industrial development of nuclear power. The objectives of the Agency's waste management programme are to assist its Member States in the safe and effective management of wastes by organizing the exchange and dissemination of information, providing guidance and technical assistance and supporting research. The current programme addresses all aspects of the industrial use of nuclear power under the aspects (a) technology of handling and treatment of wastes, (b) underground disposal of wastes, (c) environmental aspects of nuclear energy, including sea disposal of radioactive wastes. Systematic reviews have been made and publications issued concerning the technology of handling, treating, conditioning, and storing various categories of wastes, including liquid and gaseous wastes, wastes from nuclear power plants, spent fuel reprocessing and mining and milling of uranium ores, as well as wastes from decommissioning of nuclear facilities. As waste disposal is the current issue of highest interest, an Agency programme was set up in 1977 to develop a set of guidelines on the safe underground disposal of low-, intermediate- and high-level wastes in shallow ground, rock cavities or deep geological repositories. This programme will continue until 1990. Eleven Safety Series and Technical Documents and Reports have been published under this programme so far, which also addresses safety and other criteria for waste disposal. The environmental part of the waste management programme is concerned with the assessment of radiological and non-radiological consequences of discharges from nuclear facilities, including de minimis concepts in waste disposal and environmental models and data for radionuclide releases

  7. Rock mechanics activities at the Waste Isolation Pilot Plant

    Francke, C.; Saeb, S.

    1996-01-01

    The application of rock mechanics at nuclear waste repositories is a true multidisciplinary effort. A description and historical summary of the Waste Isolation Pilot Plant (WIPP) is presented. Rock mechanics programs at the WIPP are outlined, and the current rock mechanics modeling philosophy of the Westinghouse Waste Isolation Division is discussed

  8. Activated Carbon from the Chinese Herbal Medicine Waste by H3PO4 Activation

    Tie Mi

    2015-01-01

    Full Text Available Large amounts of Chinese herbal medicine wastes produced by the medicinal factories have been mainly landfilled as waste. In this study, via phosphoric acid activation, a Chinese herbal medicine waste from Magnolia officinalis (CHMW-MO was prepared for activated carbon (CHMW-MO-AC. The effect of preparation conditions (phosphoric acid/CHMW-MO impregnation ratio, activation temperature, and time of activated carbon on yield of CHMW-MO-AC was investigated. The surface area and porous texture of the CHMW-MO-ACs were characterized by nitrogen adsorption at 77 K. The SBET and pore volume were achieved in their highest value of 920 m2/g and 0.703 cm3/g, respectively. Thermal gravity analysis and scanning electron microscope images showed that CHMW-MO-ACs have a high thermal resistance and pore development. The results indicated that CHMW-MO is a good precursor material for preparing activated carbon, and CHMW-MO-AC with well-developed mesopore volume can be prepared by H3PO4 activation.

  9. Evaluation of treatment alternatives for wastes from both spent fuel rod consolidation and miscellaneous commercial activities

    Ross, W.A.; Schneider, K.J.; Oma, K.H.; Smith, R.I.; Bunnell, L.R.

    1986-07-01

    Alternative treatments were considered for both existing commercial transuranic wastes and future wastes from spent fuel rod consolidation. Waste treatment was assumed to occur at a hypothetical central treatment facility (a Monitored Retrieval Storage [MRS] facility was used as a reference). Disposal of the waste in a geologic repository was also assumed. The waste form charcteristics, process characteristics, and costs were evaluated for each waste treatment alternative. The evaluation indicated that selection of a high volume reduction alternative can save almost $1 billion in life-cycle costs for the management of transuranic and high-activity wastes from 70,000 MTU of spent fuel compared to the reference MRS waste treatment processes. The supercompaction, arc pyrolysis and melting, and maximum volume reduction alternatives are recommended for further consideration; the latter two are recommended for further testing and demonstration

  10. Identifying well-bleached quartz using the different bleaching rates of quartz and feldspar luminescence signals

    Murray, A.S.; Thomsen, Kristina Jørkov; Masuda, N.

    2012-01-01

    When dating older sedimentary deposits using quartz, there are no unambiguous methods for identifying the presence of incomplete bleaching. Current statistical analysis of dose distributions depends entirely on the assumption that incomplete bleaching and mixing are the main causes of any excess...... dispersion in the distribution; the only existing way to test this assumption is using independent age control. Here we suggest a new approach to this question, based on the differential bleaching rates of quartz and feldspar luminescence signals. We first present data that confirm the differences...... in relative bleaching rates of quartz optically stimulated luminescence (OSL) and feldspar luminescence stimulated at 50 °C by infrared light (IR50) and feldspar luminescence stimulated at 290 °C by infrared light after a stimulation at 50 °C (pIRIR290), and use recently deposited samples to determine...

  11. Electrochemical ion-exchange for medium active liquid waste treatment

    Bridger, N.J.; Turner, A.D.

    1987-01-01

    Electrochemical ion-exchange has already been demonstrated to be a robust, effective process for the treatment of active liquid wastes -with high decontamination and volume reduction factors, and only a low energy requirement. The primary aim of this new programme is to scale up this process - initially to 0.1m 3 /h, and ultimately to 1 3 m/h. A new 0.4m 2 electrode module has been designed and constructed, together with 3m 3 feed tanks for the first phase of this work. Further development work is also being carried out on alternative electrode designs and fabrication methods, as well as new exchange media (including inorganic absorbers and organic chelating resins) in order to optimize selectivity performance. (author)

  12. HYDROGEN PEROXIDE BLEACHING OF CMP PULP USING MAGNESIUM HYDROXIDE

    Farhad Zeinaly

    2009-11-01

    Full Text Available Conventional bleaching of hardwood CMP pulp with magnesium hydroxide (Mg(OH2 show significant benefits over bleaching with sodium hydroxide (NaOH under various conditions. Magnesium hydroxide bleaching generate higher optical properties, higher pulp yield and lower effluent COD at the same chemical charge, but the physical properties were found to be similar for both processes. The initial freeness of the bleached pulps and refining value to reach a target freeness (about 350 ml. CSF were more for the Mg(OH2-based process. The residual peroxide of filtrate from the Mg(OH2-based process was very high as compared to conventional bleaching.

  13. Optimization of Dithionite Bleaching of High Yield Bagasse Pulp

    Mohamed, E.

    2005-01-01

    High yield bagasse pulp was prepared by soaking bagasse in 10 % cold sodium hydroxide for 24 hours and then refluxing for two hours at 95 degree C. Optimization of dithionite bleaching was attained by investigation of different parameters as consistency, temperature, time and ph. Effect of additives as chelating agent (EDTA) or stabilizing of bleaching solution (Zn compound and hexamethylene tetramine) was considered. The effect of air content was also studied. One and two stages bleaching of the pulp were investigated by using sodium dithionite (D) as a sole bleaching agent or after application of one stage bleaching by hydrogen peroxide to attain high brightness for high yield pulp

  14. Radioactive Demonstrations Of Fluidized Bed Steam Reforming As A Supplementary Treatment For Hanford's Low Activity Waste And Secondary Wastes

    Jantzen, C.; Crawford, C.; Cozzi, A.; Bannochie, C.; Burket, P.; Daniel, G.

    2011-01-01

    The U.S. Department of Energy's Office of River Protection (ORP) is responsible for the retrieval, treatment, immobilization, and disposal of Hanford's tank waste. Currently there are approximately 56 million gallons of highly radioactive mixed wastes awaiting treatment. A key aspect of the River Protection Project (RPP) cleanup mission is to construct and operate the Waste Treatment and Immobilization Plant (WTP). The WTP will separate the tank waste into high-level and low-activity waste (LAW) fractions, both of which will subsequently be vitrified. The projected throughput capacity of the WTP LAW Vitrification Facility is insufficient to complete the RPP mission in the time frame required by the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement (TPA), i.e. December 31, 2047. Therefore, Supplemental Treatment is required both to meet the TPA treatment requirements as well as to more cost effectively complete the tank waste treatment mission. The Supplemental Treatment chosen will immobilize that portion of the retrieved LAW that is not sent to the WTP's LAW Vitrification facility into a solidified waste form. The solidified waste will then be disposed on the Hanford site in the Integrated Disposal Facility (IDF). In addition, the WTP LAW vitrification facility off-gas condensate known as WTP Secondary Waste (WTP-SW) will be generated and enriched in volatile components such as Cs-137, I-129, Tc-99, Cl, F, and SO4 that volatilize at the vitrification temperature of 1150 C in the absence of a continuous cold cap. The current waste disposal path for the WTP-SW is to recycle it to the supplemental LAW treatment to avoid a large steady state accumulation in the pretreatment-vitrification loop. Fluidized Bed Steam Reforming (FBSR) offers a moderate temperature (700-750 C) continuous method by which LAW and/or WTP-SW wastes can be processed irrespective of whether they contain organics, nitrates, sulfates/sulfides, chlorides

  15. Laser and thermal bleaching of colour centres in sodium borate glasses

    Bukharaev, A A; Yafaev, N R [AN SSSR, Kazan. Fiziko-Tekhnicheskij Inst.

    1978-12-01

    The maximum of the additional absorption band in ..gamma..- or UV-irradiated sodium borate glasses shifts to higher energy when the low-energy side of the band is bleached by a helium-neon laser, ..lambda.. = 632.8 nm. Simultaneously the half-width of the additional absorption band decreases. This phenomenon is associated with the fact that because of structural disorder of glasses there is a distribution of ground-state energies of trapped electrons forming the light-sensitive absorption band. The distribution interval of the activation energy for trapped electrons is estimated using the decomposition of the initial thermal bleaching curves into components. For UV irradiated glasses it is aproximately 0.24 eV, and for ..gamma..-irradiated glasses only 0.12 eV. These values correlate with the relative shift maximum of the absorption band at laser bleaching.

  16. Chemical activation of tea waste and use for the removal of chromium (Vi) from aqueous solution

    Qureshi, K.; Bhatti, I.; Ansari, A.K.

    2009-01-01

    Tea waste is the residue left after the preparation of tea. At present the tea waste is regarded as a waste product having no use. In this study, tea waste is converted into an adsorbent. Tea waste is chemically activated with phosphoric acid at low temperature 450 degree C. This activated carbon is then utilized as an adsorbent for the removal of Chromium (VI) from aqueous solution. The various sorption parameters i.e pH, sorbent dose sorbate concentration, shaking time and shaking speed are first optimized. 75% of chromium from aqueous solution is effectively removed at pH 2. The best optimum conditions were obtained when 1 gm of sorbent was agitated at 100 rpm with 60 mg/l of sorbate for 50 minutes. Better results were obtained when low concentrations of sorbates were used. Hence tea waste could also be successfully used for the sorption of Chromium (VI), from industrial waste water. (author)

  17. REMINERALIZATION POTENTIAL OF A CARBAMIDE BLEACHING AGENT

    Marinova-Takorova Borislavova Mirela

    2016-03-01

    Full Text Available Background: Bleaching has gradually became a popular procedure for people searching for aesthetic improvement. The aim of this in vitro study was to investigate the effect of bleaching with 45% carbamide peroxide on the level of mineralization of enamel, using laser fluorescence. Materials and methods: Sixty extracted human teeth were treated with 45% carbamid peroxide (Opalescence, Ultradent, 4 consecutive days for one hour each day. The effect of the bleaching agent on the level of mineralization of enamel was measured with DIAGNO dent pen. The statistical method we use was descriptive analysis. Results: The average values, measured before the applications of the carbamid peroxide were 6.33. On the first day they were 5.41, on the second 5.38, on the third 5.11 and 5.35 on the forth. Conclusion: There was observed a slight remineralization effect due to the incorporated Ca2+ and F- ions in the bleaching agent that we have used.

  18. Enzymes improve ECF bleaching of pulp

    Lachenal, D.

    2006-07-01

    Full Text Available The delignification efficiency of different laccase enzymes was examined on the eucalyptus Kraft pulp. The laccase enzyme from Trametes versicolor showing the highest delignification efficiency was selected and used in the elemental chlorine-free bleaching sequence for improving the pulp bleachability. An appreciable reduction in chlorine dioxide consumption was also obtained. Further reduction in chlorine dioxide consumption was obtained when the same laccase treated pulp was subjected to an acid treatment after the extraction stage followed by the DEPD sequence. Elemental-chlorine free bleaching was also performed using the xylanase-laccase treated pulp. Xylanase treatment was incorporated to the laccase mediator system in the elemental-chlorine free bleaching both sequentially and simultaneously. The bleaching sequence DEPD followed and in both the cases, the reduction in chlorine dioxide consumption was greater in comparison to the control. The chlorine dioxide consumption was reduced further when xylanase-laccase treated pulp was given an additional acid treatment. The final pulp properties of the treated pulps were comparable to the control pulp.

  19. BLEACHING EUCALYPTUS PULPS WITH SHORT SEQUENCES

    Flaviana Reis Milagres

    2011-03-01

    Full Text Available Eucalyptus spp kraft pulp, due to its high content of hexenuronic acids, is quite easy to bleach. Therefore, investigations have been made attempting to decrease the number of stages in the bleaching process in order to minimize capital costs. This study focused on the evaluation of short ECF (Elemental Chlorine Free and TCF (Totally Chlorine Free sequences for bleaching oxygen delignified Eucalyptus spp kraft pulp to 90% ISO brightness: PMoDP (Molybdenum catalyzed acid peroxide, chlorine dioxide and hydrogen peroxide, PMoD/P (Molybdenum catalyzed acid peroxide, chlorine dioxide and hydrogen peroxide, without washing PMoD(PO (Molybdenum catalyzed acid peroxide, chlorine dioxide and pressurized peroxide, D(EPODP (chlorine dioxide, extraction oxidative with oxygen and peroxide, chlorine dioxide and hydrogen peroxide, PMoQ(PO (Molybdenum catalyzed acid peroxide, DTPA and pressurized peroxide, and XPMoQ(PO (Enzyme, molybdenum catalyzed acid peroxide, DTPA and pressurized peroxide. Uncommon pulp treatments, such as molybdenum catalyzed acid peroxide (PMo and xylanase (X bleaching stages, were used. Among the ECF alternatives, the two-stage PMoD/P sequence proved highly cost-effective without affecting pulp quality in relation to the traditional D(EPODP sequence and produced better quality effluent in relation to the reference. However, a four stage sequence, XPMoQ(PO, was required to achieve full brightness using the TCF technology. This sequence was highly cost-effective although it only produced pulp of acceptable quality.

  20. Design requirements document for project W-520, immobilized low-activity waste disposal

    Ashworth, S.C.

    1998-01-01

    This design requirements document (DRD) identifies the functions that must be performed to accept, handle, and dispose of the immobilized low-activity waste (ILAW) produced by the Tank Waste Remediation System (TWRS) private treatment contractors and close the facility. It identifies the requirements that are associated with those functions and that must be met. The functional and performance requirements in this document provide the basis for the conceptual design of the Tank Waste Remediation System Immobilized Low-Activity Waste disposal facility project (W-520) and provides traceability from the program-level requirements to the project design activity

  1. Design requirements document for project W-520, immobilized low-activity waste disposal

    Ashworth, S.C.

    1998-08-06

    This design requirements document (DRD) identifies the functions that must be performed to accept, handle, and dispose of the immobilized low-activity waste (ILAW) produced by the Tank Waste Remediation System (TWRS) private treatment contractors and close the facility. It identifies the requirements that are associated with those functions and that must be met. The functional and performance requirements in this document provide the basis for the conceptual design of the Tank Waste Remediation System Immobilized Low-Activity Waste disposal facility project (W-520) and provides traceability from the program-level requirements to the project design activity.

  2. Long-term management of wastes resulting from dismantling operations. Storing the very low-level activity wastes at Morvilliers

    Duret, F.; Dutzer, M.; Beranger, V.; Lecoq, P.

    2003-01-01

    Extension of dismantling operations in France in the years to come poses the question of availability of long-term waste facility. Large amount of such wastes will be produced after progressive shutdown of the 58 pressurized water reactors now in operation, not before 2010. However, France is already confronted with dismantling of 9 power reactors (6 of which of gas cooled graphite type), the first reprocessing plant at Marcoule, as well as, dismantling of other installations, for instance the CEA reactors or laboratories. The systems of processing the dismantling waste are not different from those used for wastes resulting from nuclear operations. For the high-level or long-term intermediate level activity disposal the debates must start by 2006, as based on the results of the research conducted according to different provisions of the December 30, 1991 law. These wastes represent however small amounts from the dismantling (around 2000 t for the 9 reactors at shutdown) and they will be stored until a decision will be made. A specific storing system should be implemented by 2008-2010 for the graphite wastes (around 23,000 t) which contain significant amount of long-lived radioelements, although their gross activity is low. But the most significant amount will come from low-level or intermediate-level of short lifetime or from wastes of very low activity. The first category is stored at Storage Center at Aube (CSA), its capacity being of 1,000,000 m 3 of drums. The total volume stored by the end of 2002 amounted 136,500 m 3 with an annual delivering of 12-15,000 m 3 at design rate of 30,000 m 3 /y. This center will be able to absorb the flux increase resulting from dismantling of the decommissioned nuclear installations (around 50,000 t from the dismantling of the 9 power reactor). The Center at Aube can be also adapted for storing wastes of large sizes as for instance the lid of the reactor vessel. According to the French regulation, the wastes produced within a

  3. Global warming and recurrent mass bleaching of corals

    Hughes, Terry P.; Kerry, James T.; Álvarez-Noriega, Mariana; Álvarez-Romero, Jorge G.; Anderson, Kristen D.; Baird, Andrew H.; Babcock, Russell C.; Beger, Maria; Bellwood, David R.; Berkelmans, Ray; Bridge, Tom C.; Butler, Ian R.; Byrne, Maria; Cantin, Neal E.; Comeau, Steeve; Connolly, Sean R.; Cumming, Graeme S.; Dalton, Steven J.; Diaz-Pulido, Guillermo; Eakin, C. Mark; Figueira, Will F.; Gilmour, James P.; Harrison, Hugo B.; Heron, Scott F.; Hoey, Andrew S.; Hobbs, Jean-Paul A.; Hoogenboom, Mia O.; Kennedy, Emma V.; Kuo, Chao-Yang; Lough, Janice M.; Lowe, Ryan J.; Liu, Gang; McCulloch, Malcolm T.; Malcolm, Hamish A.; McWilliam, Michael J.; Pandolfi, John M.; Pears, Rachel J.; Pratchett, Morgan S.; Schoepf, Verena; Simpson, Tristan; Skirving, William J.; Sommer, Brigitte; Torda, Gergely; Wachenfeld, David R.; Willis, Bette L.; Wilson, Shaun K.

    2017-03-01

    During 2015-2016, record temperatures triggered a pan-tropical episode of coral bleaching, the third global-scale event since mass bleaching was first documented in the 1980s. Here we examine how and why the severity of recurrent major bleaching events has varied at multiple scales, using aerial and underwater surveys of Australian reefs combined with satellite-derived sea surface temperatures. The distinctive geographic footprints of recurrent bleaching on the Great Barrier Reef in 1998, 2002 and 2016 were determined by the spatial pattern of sea temperatures in each year. Water quality and fishing pressure had minimal effect on the unprecedented bleaching in 2016, suggesting that local protection of reefs affords little or no resistance to extreme heat. Similarly, past exposure to bleaching in 1998 and 2002 did not lessen the severity of bleaching in 2016. Consequently, immediate global action to curb future warming is essential to secure a future for coral reefs.

  4. Global warming and recurrent mass bleaching of corals.

    Hughes, Terry P; Kerry, James T; Álvarez-Noriega, Mariana; Álvarez-Romero, Jorge G; Anderson, Kristen D; Baird, Andrew H; Babcock, Russell C; Beger, Maria; Bellwood, David R; Berkelmans, Ray; Bridge, Tom C; Butler, Ian R; Byrne, Maria; Cantin, Neal E; Comeau, Steeve; Connolly, Sean R; Cumming, Graeme S; Dalton, Steven J; Diaz-Pulido, Guillermo; Eakin, C Mark; Figueira, Will F; Gilmour, James P; Harrison, Hugo B; Heron, Scott F; Hoey, Andrew S; Hobbs, Jean-Paul A; Hoogenboom, Mia O; Kennedy, Emma V; Kuo, Chao-Yang; Lough, Janice M; Lowe, Ryan J; Liu, Gang; McCulloch, Malcolm T; Malcolm, Hamish A; McWilliam, Michael J; Pandolfi, John M; Pears, Rachel J; Pratchett, Morgan S; Schoepf, Verena; Simpson, Tristan; Skirving, William J; Sommer, Brigitte; Torda, Gergely; Wachenfeld, David R; Willis, Bette L; Wilson, Shaun K

    2017-03-15

    During 2015-2016, record temperatures triggered a pan-tropical episode of coral bleaching, the third global-scale event since mass bleaching was first documented in the 1980s. Here we examine how and why the severity of recurrent major bleaching events has varied at multiple scales, using aerial and underwater surveys of Australian reefs combined with satellite-derived sea surface temperatures. The distinctive geographic footprints of recurrent bleaching on the Great Barrier Reef in 1998, 2002 and 2016 were determined by the spatial pattern of sea temperatures in each year. Water quality and fishing pressure had minimal effect on the unprecedented bleaching in 2016, suggesting that local protection of reefs affords little or no resistance to extreme heat. Similarly, past exposure to bleaching in 1998 and 2002 did not lessen the severity of bleaching in 2016. Consequently, immediate global action to curb future warming is essential to secure a future for coral reefs.

  5. Removal of Methylene Blue from aqueous solution using spent bleaching earth

    Saputra, E.; Saputra, R.; Nugraha, M. W.; Irianty, R. S.; Utama, P. S.

    2018-04-01

    The waste from industrial textile waste is one of the environmental problems, it is required effective and efficient processing. In this study spent bleaching earth was used as absorbent. It was found that the absorbent was effective to remove methylene blue from aqueous solution with removal efficiency 99.97 % in 120 min. Several parameters such as pH, amount of absorbent loading, stirring speed are found as key factor influencing removal of methylene blue. The mechanism of adsorption was also studied, and it was found that Langmuir isotherm fitted to data of experiment with adsorption capacity 0.5 mg/g.

  6. Technical basis for classification of low-activity waste fraction from Hanford site tanks

    Petersen, C.A., Westinghouse Hanford

    1996-07-17

    The overall objective of this report is to provide a technical basis to support a U.S. Nuclear Regulatory Commission determination to classify the low-activity waste from the Hanford Site single-shell and double-shell tanks as `incidental` wastes after removal of additional radionuclides and immobilization.The proposed processing method, in addition to the previous radionuclide removal efforts, will remove the largest practical amount of total site radioactivity, attributable to high-level wastes, for disposal in a deep geologic repository. The remainder of the waste would be considered `incidental` waste and could be disposed onsite.

  7. Technical basis for classification of low-activity waste fraction from Hanford site tanks

    Petersen, C.A.

    1996-09-20

    The overall objective of this report is to provide a technical basis to support a U.S. Nuclear Regulatory Commission determination to classify the low-activity waste from the Hanford Site single-shell and double-shell tanks as `incidental` wastes after removal of additional radionuclides and immobilization.The proposed processing method, in addition to the previous radionuclide removal efforts, will remove the largest practical amount of total site radioactivity, attributable to high-level waste, for disposal is a deep geologic repository. The remainder of the waste would be considered `incidental` waste and could be disposed onsite.

  8. Processing method and processing device for liquid waste containing surface active agent and radioactive material

    Nishi, Takashi; Matsuda, Masami; Baba, Tsutomu; Yoshikawa, Ryozo; Yukita, Atsushi.

    1998-01-01

    Washing liquid wastes containing surface active agents and radioactive materials are sent to a deaerating vessel. Ozone is blown into the deaerating vessel. The washing liquid wastes dissolved with ozone are introduced to a UV ray irradiation vessel. UV rays are irradiated to the washing liquid wastes, and hydroxy radicals generated by photodecomposition of dissolved ozone oxidatively decompose surface active agents contained in the washing liquid wastes. The washing liquid wastes discharged from the UV ray irradiation vessel are sent to an activated carbon mixing vessel and mixed with powdery activated carbon. The surface active agents not decomposed in the UV ray irradiation vessel are adsorbed to the activated carbon. Then, the activated carbon and washing liquid wastes are separated by an activated carbon separating/drying device. Radioactive materials (iron oxide and the like) contained in the washing liquid wastes are mostly granular, and they are separated and removed from the washing liquid wastes in the activated carbon separating/drying device. (I.N.)

  9. Perbandingan intensitas warna CPO dengan menggunakan Bleaching Earth (BE) dan Spent Bleaching Earth (SBE) di PT. SMART Tbk.

    Aritonang, Dwi Christina

    2016-01-01

    Comparative studies have been conducted on the effect of bleaching earth quality bleachibility power on CPO (crude palm oil). by using the tool Lovibond Tintometer model of F in PT Smart Tbk Medan – Belawan.From experiments obtained initial color with the CPO 20R - 20Y after addition Bleaching Earth and spent bleaching earth with the CPO each - each 10,2R - 20Y and 17.3R - 20Y . The results showed that purification using Bleaching Earth better than the purification of Spent Bleaching Earh ...

  10. Identification of items and activities important to waste form acceptance by Westinghouse GoCo sites

    Plodinec, M.J.; Marra, S.L.; Dempster, J.; Randklev, E.H.

    1993-01-01

    The Department of Energy has established specifications (Waste Acceptance Product Specifications for Vitrified High-Level Waste Forms, or WAPS) for canistered waste forms produced at Hanford, Savannah River, and West Valley. Compliance with these specifications requires that each waste form producer identify the items and activities which must be controlled to ensure compliance. As part of quality assurance oversight activities, reviewers have tried to compare the methodologies used by the waste form producers to identify items and activities important to waste form acceptance. Due to the lack of a documented comparison of the methods used by each producer, confusion has resulted over whether the methods being used are consistent. This confusion has been exacerbated by different systems of nomenclature used by each producer, and the different stages of development of each project. The waste form producers have met three times in the last two years, most recently on June 28, 1993, to exchange information on each producer's program. These meetings have been sponsored by the Westinghouse GoCo HLW Vitrification Committee. This document is the result of this most recent exchange. It fills the need for a documented comparison of the methodologies used to identify items and activities important to waste form acceptance. In this document, the methodology being used by each waste form producer is summarized, and the degree of consistency among the waste form producers is determined

  11. In-Office Bleaching During Orthodontic Treatment.

    Gomes, Mauricio Neves; Dutra, Hélio; Morais, Alexandre; Sgura, Ricardo; Devito-Moraes, André Guaraci

    2017-04-01

    To demonstrate that it is possible to pursue teeth whitening treatment protocols during orthodontic treatment with no esthetic loss. Many patients undergoing orthodontic treatment desire to have a straight and well aligned dentition, but also whiter teeth. For many years, it was believed that carrying out a whitening treatment with positioned orthodontic brackets in place would result in localized spots on the enamel labial surfaces of teeth. However, a deeper understanding of the bleaching process suggests that the oxidation caused by products, which results from hydrogen peroxide decomposition, are able to diffuse peripherally into the tooth structure and reach even that under the cemented brackets. Two in-office-bleaching treatments were performed in patients using orthodontic fixed braces in two or three 40-minute sessions using a 35% hydrogen peroxide. In-office bleaching is possible and effective, even with orthodontic brackets in position. The teeth were successfully bleached despite the presence of brackets. All biological criteria have been fulfilled satisfying patients' expectations of aligned and whitened teeth in less time than if treatments had been performed separately, with satisfactory results and no esthetic loss. The whitening of teeth is possible during orthodontic treatment with fixed braces without any esthetic loss. The in-office bleaching treatment with brackets in position also may act as a motivation factor, preventing patient withdrawal or treatment interruption. Therefore, at the end of the orthodontic treatment, the patient is able to display an aligned, functional and whitened smile. (J Esthet Restor Dent 29:83-92, 2017). © 2016 Wiley Periodicals, Inc.

  12. Removal of phenol from radioactive waste solutions using activated granular Carbon and activated vermiculite

    Ezz El-Din, M.R.; Atta, E.R.

    2006-01-01

    The efficiency of both activated granular carbon (AGC) and activated vermiculite (AV) in removal of phenol from aqueous waste solutions is of great interest. The aim of the present study is to compare the absorbance capacities of both AGC and AV for the removal of phenol from radioactive waste solutions and to identify the factors affecting the sorption process. The experimental results were in the form of batch sorption measurements for the removal of phenol at ambient temperature (29 ± 1 degree C) and for times up to 40 min and 180 min for AGC and AV, respectively. The results indicated that activated carbon has good efficiency to adsorb phenol. Freundlich equation has been fitted to both AGC and AV for the contaminant removal. The adsorption capacities of both AGC and AV to phenol were 17.4 mg g-1 and 4.5 mg g-1, respectively. The maximum desorption percent of phenol from both loaded AGC and loaded AV were 9 % and 0 %, respectively, and it attained within about 200 min. accordingly, it is recommended that activated carbon is preferred in the applied field for removing phenol from radioactive aqueous wastes

  13. The Transuranic Waste Program's integration and planning activities and the contributions of the TRU partnership

    Harms, T.C.; O'Neal, W.; Petersen, C.A.; McDonald, C.E.

    1994-02-01

    The Technical Support Division, EM-351 manages the integration and planning activities of the Transuranic Waste Program. The Transuranic Waste Program manager provides transuranic waste policy, guidance, and issue resolution to Headquarters and the Operations Offices. In addition, the program manager is responsible for developing and implementing an integrated, long-range waste management plan for the transuranic waste system. A steering committee, a core group of support contractors, and numerous interface working groups support the efforts of the program manager. This paper provides an overview of the US Department of Energy's transuranic waste integration activities and a long-range planning process that includes internal and external stakeholder participation. It discusses the contributions and benefits provided by the Transuranic Partnership, most significantly, the integration activities and the body of data collected and assembled by the Partnership

  14. Bulk Vitrification Technology For The Treatment And Immobilization Of Low-Activity Waste

    Ard, K.E.

    2011-01-01

    This report is one of four reports written to provide background information regarding immobilization technologies under consideration for supplemental immobilization of Hanford's low-activity waste. This paper is intended to provide the reader with general understanding of Bulk Vitrification and how it might be applied to immobilization of Hanford's low-activity waste.

  15. Human health and ecological risks from environmental restoration and waste management activities

    Pehlman, P.A.; Wollert, D.A.; Phillippi, R.H.

    1994-01-01

    This paper summarizes the methodologies for estimating human health and ecological risks resulting from Environmental Restoration and Waste Management activities across the Department of Energy (DOE) complex. DOE is currently assessing these activities as part of the Environmental Restoration and Waste Management Programmatic Environmental Impact Statement (EM-PEIS)

  16. Fluidized Bed Steam Reforming For Treatment And Immobilization Of Low-Activity Waste

    Hewitt, W.M.

    2011-01-01

    This report is one of four reports written to provide background information regarding immobilization technologies remaining under consideration for supplemental immobilization of Hanford's low-activity waste. This paper provides the reader a general understanding of fluidized bed steam reforming and its possible application to treat and immobilize Hanford low-activity waste.

  17. A Joule-Heated Melter Technology For The Treatment And Immobilization Of Low-Activity Waste

    Kelly, S.E.

    2011-01-01

    This report is one of four reports written to provide background information regarding immobilization technologies remaining under consideration for supplemental immobilization of Hanford's low-activity waste. This paper provides the reader a general understanding of joule-heated ceramic lined melters and their application to Hanford's low-activity waste.

  18. BULK VITRIFICATION TECHNOLOGY FOR THE TREATMENT AND IMMOBILIZATION OF LOW-ACTIVITY WASTE

    ARD KE

    2011-04-11

    This report is one of four reports written to provide background information regarding immobilization technologies under consideration for supplemental immobilization of Hanford's low-activity waste. This paper is intended to provide the reader with general understanding of Bulk Vitrification and how it might be applied to immobilization of Hanford's low-activity waste.

  19. A JOULE-HEATED MELTER TECHNOLOGY FOR THE TREATMENT AND IMMOBILIZATION OF LOW-ACTIVITY WASTE

    KELLY SE

    2011-04-07

    This report is one of four reports written to provide background information regarding immobilization technologies remaining under consideration for supplemental immobilization of Hanford's low-activity waste. This paper provides the reader a general understanding of joule-heated ceramic lined melters and their application to Hanford's low-activity waste.

  20. FLUIDIZED BED STEAM REFORMING FOR TREATMENT AND IMMOBILIZATION OF LOW-ACTIVITY WASTE

    HEWITT WM

    2011-04-08

    This report is one of four reports written to provide background information regarding immobilization technologies remaining under consideration for supplemental immobilization of Hanford's low-activity waste. This paper provides the reader a general understanding of fluidized bed steam reforming and its possible application to treat and immobilize Hanford low-activity waste.

  1. Thermographic and spectrophotometric analysis of the extrinsic tooth bleaching using a diode laser and a LED system. In vitro

    Micheli, Paola Racy de

    2004-01-01

    The aim of this study was to evaluate the intra-pulpal temperature change, as well as to compare the bleaching power of a 38% hydrogen peroxide (Opalescence Xtra Boost- Ultradent. Inc), when activated with a diode laser, with a LED system and without activation, in the extrinsic tooth bleaching in vitro. Ten mandibular human incisors, a thermocouple, 45 bovine incisors and a spectrophotometer (Shade Eye- Shofu) for the color analysis. The samples were divided into 3 groups: 38% hydrogen peroxide activated by a diode laser (ZAP lasers, wavelength 808 nm ± 5, power of 1,4 W); 38% hydrogen peroxide activated by LED (Bright LEC-Mmoptics, wavelength 470 nm ± 25, power of 380 mW); 38% hydrogen peroxide without activation. After the artificial pigmentation, the bleaching agent acted for the same time in the 3 groups, differing only by the type of activation. The results of temperature showed that the LED activation was safer than the diode laser, which, in some measures exceeded the limit of 5.6 deg C. The luminosity of the samples did not show significantly statistics differences in none of the groups and moments of this study. The diode laser and LED activation did not influenced at the bleaching power of the peroxide, which showed effective for removing stains, with great capacity of bleaching bovine tooth artificially darkened. (author)

  2. USDOE activities in low-level radioactive waste treatment

    Vath, J.E.

    1981-01-01

    This paper describes current research, development and demonstration (R, D and D) programs sponsored by the US Department of Energy in the area of low-level radioactive waste treatment. During the twelve month period ending September 30, 1981, 14 prime US Department of Energy contractors were involved with over 40 low-level radioactive waste disposal technology projects. Three specific projects or task areas have been selected for discussion to illustrate new and evolving technologies, and application of technology developed in other waste management areas to low-level waste treatment. The areas to be discussed include a microwave plasma torch incinerator, application of waste vitrification, and decontamination of metal waste by melting

  3. The treatment of active waste from a PIE facility

    Turier, C.A.; Kerswell, A.G.

    1978-09-01

    The types of radioactive waste produced in the post irradiation examination of nuclear fuel elements from several classes of reactor are described. Other radioactive wastes may be produced in cave facilities as a result of contamination of the equipment. The methods of disposal of all types of waste are considered, together with methods to improve the operation of the caves. The training of cave operators, and the use of method study to collect information in cave operations are considered also. (U.K.)

  4. Supplemental Immobilization of Hanford Low-Activity Waste: Cast Stone Screening Tests

    Westsik, Joseph H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Piepel, Gregory F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lindberg, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Heasler, Patrick G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mercier, Theresa M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Russell, Renee L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cozzi, Alex [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Daniel, William E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Eibling, Russell E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hansen, E. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Reigel, Marissa M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Swanberg, David J. [Washington River Protection Solutions (WRPS), Aiken, SC (United States)

    2013-09-30

    More than 56 million gallons of radioactive and hazardous waste are stored in 177 underground storage tanks at the U.S. Department of Energy’s (DOE’s) Hanford Site in southeastern Washington State. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the wastes and immobilize them in a glass waste form. The WTP includes a pretreatment facility to separate the wastes into a small volume of high-level waste (HLW) containing most of the radioactivity and a larger volume of low-activity waste (LAW) containing most of the nonradioactive chemicals. The HLW will be converted to glass in the HLW vitrification facility for ultimate disposal at an offsite federal repository. At least a portion (~35%) of the LAW will be converted to glass in the LAW vitrification facility and will be disposed of onsite at the Integrated Disposal Facility (IDF). The pretreatment and HLW vitrification facilities will have the capacity to treat and immobilize the wastes destined for each facility. However, a second LAW immobilization facility will be needed for the expected volume of LAW requiring immobilization. A cementitious waste form known as Cast Stone is being considered to provide the required additional LAW immobilization capacity. The Cast Stone waste form must be acceptable for disposal in the IDF. The Cast Stone waste form and immobilization process must be tested to demonstrate that the final Cast Stone waste form can comply with the waste acceptance criteria for the disposal facility and that the immobilization processes can be controlled to consistently provide an acceptable waste form product. Further, the waste form must be tested to provide the technical basis for understanding the long-term performance of the waste form in the disposal environment. These waste form performance data are needed to support risk assessment and performance assessment (PA) analyses of the long-term environmental impact of the waste disposal in the IDF

  5. The very-low activity waste storage facility. A new waste management system; Le centre de stockage des dechets de tres faible activite. Une nouvelle filiere de gestion

    NONE

    2006-07-01

    Very-low activity wastes have a radioactivity level close to the natural one. This category of waste is taken into consideration by the French legislation and their storage is one of their point of achievement. This document gives a complete overview of the principles of storage implemented at the storage center for very-low activity wastes (CSTFA) sited in the Aube departement in the vicinity of the storage center for low- and intermediate activity wastes: storage concept, wastes confinement, center organization, environmental monitoring. (J.S.)

  6. Endoglucanase post-milling treatment for producing cellulose nanofibers from bleached eucalyptus fibers by a supermasscolloider

    Wangxia Wang; Michael D. Mozuch; Ronald C. Sabo; Philip Kersten; Junyong Zhu; Yongcan Jin

    2016-01-01

    Three recombinant GH5 endoglucanases chosen for their contrasting hydrolytic activities, and a commercial endoglucanase were used to treat cellulose nanofibers (CNFs) after they were milled from bleached eucalyptus pulp with a supermasscolloider. This enzyme ‘‘post-treatment’’ resulted in different properties for the CNFs depending on enzyme treatment. The degree of...

  7. Changes in bleaching susceptibility among corals subject to ocean warming and recurrent bleaching in Moorea, French Polynesia.

    Pratchett, Morgan S; McCowan, Dominique; Maynard, Jeffrey A; Heron, Scott F

    2013-01-01

    Climate-induced coral bleaching poses a major threat to coral reef ecosystems, mostly because of the sensitivities of key habitat-forming corals to increasing temperature. However, susceptibility to bleaching varies greatly among coral genera and there are likely to be major changes in the relative abundance of different corals, even if the wholesale loss of corals does not occur for several decades. Here we document variation in bleaching susceptibility among key genera of reef-building corals in Moorea, French Polynesia, and compare bleaching incidence during mass-bleaching events documented in 1991, 1994, 2002 and 2007. This study compared the proportion of colonies that bleached for four major genera of reef-building corals (Acropora, Montipora, Pocillopora and Porites), during each of four well-documented bleaching events from 1991 to 2007. Acropora and Montipora consistently bleached in far greater proportions (up to 98%) than Pocillopora and Porites. However, there was an apparent and sustained decline in the proportion of colonies that bleached during successive bleaching events, especially for Acropora and Montipora. In 2007, only 77% of Acropora colonies bleached compared with 98% in 1991. Temporal variation in the proportion of coral colonies bleached may be attributable to differences in environmental conditions among years. Alternately, the sustained declines in bleaching incidence among highly susceptible corals may be indicative of acclimation or adaptation. Coral genera that are highly susceptible to coral bleaching, and especially Acropora and Montipora, exhibit temporal declines in their susceptibility to thermal anomalies at Moorea, French Polynesia. One possible explanation for these findings is that gradual removal of highly susceptible genotypes (through selective mortality of individuals, populations, and/or species) is producing a coral assemblage that is more resistant to sustained and ongoing ocean warming.

  8. Changes in Bleaching Susceptibility among Corals Subject to Ocean Warming and Recurrent Bleaching in Moorea, French Polynesia

    Pratchett, Morgan S.; McCowan, Dominique; Maynard, Jeffrey A.; Heron, Scott F.

    2013-01-01

    Background Climate-induced coral bleaching poses a major threat to coral reef ecosystems, mostly because of the sensitivities of key habitat-forming corals to increasing temperature. However, susceptibility to bleaching varies greatly among coral genera and there are likely to be major changes in the relative abundance of different corals, even if the wholesale loss of corals does not occur for several decades. Here we document variation in bleaching susceptibility among key genera of reef-building corals in Moorea, French Polynesia, and compare bleaching incidence during mass-bleaching events documented in 1991, 1994, 2002 and 2007. Methodology/Principal Findings This study compared the proportion of colonies that bleached for four major genera of reef-building corals (Acropora, Montipora, Pocillopora and Porites), during each of four well-documented bleaching events from 1991 to 2007. Acropora and Montipora consistently bleached in far greater proportions (up to 98%) than Pocillopora and Porites. However, there was an apparent and sustained decline in the proportion of colonies that bleached during successive bleaching events, especially for Acropora and Montipora. In 2007, only 77% of Acropora colonies bleached compared with 98% in 1991. Temporal variation in the proportion of coral colonies bleached may be attributable to differences in environmental conditions among years. Alternately, the sustained declines in bleaching incidence among highly susceptible corals may be indicative of acclimation or adaptation. Conclusions/Significance Coral genera that are highly susceptible to coral bleaching, and especially Acropora and Montipora, exhibit temporal declines in their susceptibility to thermal anomalies at Moorea, French Polynesia. One possible explanation for these findings is that gradual removal of highly susceptible genotypes (through selective mortality of individuals, populations, and/or species) is producing a coral assemblage that is more resistant to

  9. An overview of the AECB's strategy for regulating radioactive waste management activities

    Hamel, P.E.; Smythe, W.D.; Duncan, R.M.; Coady, J.R.

    1982-07-01

    The goal of the Canadian Atomic Energy Control Board in regulating the management of radioactive wastes is to ensure the protection of people and the environment. A program of cooperation with other agencies, identification and adoption of baselines for describing radioactive wastes, development of explicit criteria and requirements, publication of related regulatory documents, establishment of independent consultative processes with technical experts and the public, and maintenance of awareness and compatibility with international activities is underway. Activities related to high-level radioactive waste, uranium mine and mill tailings, low- and medium-level wastes, radioactive effluents from nuclear facilities, and decommissioning and decontamination are described

  10. Development of activated carbon pore structure via physical and chemical activation of biomass fibre waste

    Williams, Paul T.; Reed, Anton R.

    2006-01-01

    Biomass waste in the form of biomass flax fibre, produced as a by-product of the textile industry was processed via both physical and chemical activation to produce activated carbons. The surface area of the physically activated carbons were up to 840 m 2 g -1 and the carbons were of mesoporous structure. Chemical activation using zinc chloride produced high surface area activated carbons up to 2400 m 2 g -1 and the pore size distribution was mainly microporous. However, the process conditions of temperature and zinc chloride concentration could be used to manipulate the surface area and porosity of the carbons to produce microporous, mesoporous and mixed microporous/mesoporous activated carbons. The physically activated carbons were found to be a mixture of Type I and Type IV carbons and the chemically activated carbons were found to be mainly Type I carbons. The development of surface morphology of physically and chemically activated carbons observed via scanning electron microscopy showed that physical activation produced activated carbons with a nodular and pitted surface morphology whereas activated carbons produced through chemical activation had a smooth surface morphology. Transmission electron microscopy analysis could identify mesopore structures in the physically activated carbon and microporous structures in the chemically activated carbons

  11. Coral bleaching response index: a new tool to standardize and compare susceptibility to thermal bleaching.

    Swain, Timothy D; Vega-Perkins, Jesse B; Oestreich, William K; Triebold, Conrad; DuBois, Emily; Henss, Jillian; Baird, Andrew; Siple, Margaret; Backman, Vadim; Marcelino, Luisa

    2016-07-01

    As coral bleaching events become more frequent and intense, our ability to predict and mitigate future events depends upon our capacity to interpret patterns within previous episodes. Responses to thermal stress vary among coral species; however the diversity of coral assemblages, environmental conditions, assessment protocols, and severity criteria applied in the global effort to document bleaching patterns creates challenges for the development of a systemic metric of taxon-specific response. Here, we describe and validate a novel framework to standardize bleaching response records and estimate their measurement uncertainties. Taxon-specific bleaching and mortality records (2036) of 374 coral taxa (during 1982-2006) at 316 sites were standardized to average percent tissue area affected and a taxon-specific bleaching response index (taxon-BRI) was calculated by averaging taxon-specific response over all sites where a taxon was present. Differential bleaching among corals was widely variable (mean taxon-BRI = 25.06 ± 18.44%, ±SE). Coral response may differ because holobionts are biologically different (intrinsic factors), they were exposed to different environmental conditions (extrinsic factors), or inconsistencies in reporting (measurement uncertainty). We found that both extrinsic and intrinsic factors have comparable influence within a given site and event (60% and 40% of bleaching response variance of all records explained, respectively). However, when responses of individual taxa are averaged across sites to obtain taxon-BRI, differential response was primarily driven by intrinsic differences among taxa (65% of taxon-BRI variance explained), not conditions across sites (6% explained), nor measurement uncertainty (29% explained). Thus, taxon-BRI is a robust metric of intrinsic susceptibility of coral taxa. Taxon-BRI provides a broadly applicable framework for standardization and error estimation for disparate historical records and collection of novel

  12. Improved sensitivity, safety and laboratory turnaround time in the diagnosis of pulmonary tuberculosis by use of bleach sedimentation

    Ameh James

    2015-11-01

    Full Text Available Background: Inadequate diagnostic processes and human resources in laboratories contribute to a high burden of tuberculosis (TB in low- and middle-income countries. Direct smear microscopy is relied on for TB diagnosis; however, sensitivity rates vary. To improve sensitivity of direct microscopy, the researchers employed several approaches, including sputum digestion and concentration of acid-fast bacilli (AFB, a technique which uses commercial bleach. Objectives: This study compared methods used to diagnose active Mycobacterium tuberculosis infections. Methods: Three sputum specimens were collected from each of 340 participants in Abuja, Nigeria, over two consecutive days. Direct microscopy was performed on all specimens; following microscopy, one specimen from each patient was selected randomly for bleach sedimentation and one for Lowenstein-Jensen culture. Results: Direct microscopy produced 28.8% AFB-positive results, whilst bleach sedimentation resulted in 30.3%. When compared with the cultures, 26.5% were AFB true positive using direct microscopy and 27.1% using bleach sedimentation. Whilst the specificity rate between these two methods was not statistically significant (P = 0.548, the sensitivity rate was significant (P = 0.004. Conclusion: Based on these results, bleach increases the sensitivity of microscopy compared with direct smear and has similar specificity. When diagnosing new cases of pulmonary TB, one bleach-digested smear is as sensitive as three direct smears, reducing waiting times for patients and ensuring the safety of laboratory technicians.

  13. Wastes from selected activities in two light-water reactor fuel cycles

    Palmer, C.R.; Hill, O.F.

    1980-07-01

    This report presents projected volumes and radioactivities of wastes from the production of electrical energy using light-water reactors (LWR). The projections are based upon data developed for a recent environmental impact statement in which the transuranic wastes (i.e., those wastes containing certain long-lived alpha emitters at concentrations of at least 370 becquerels, or 10 nCi, per gram of waste) from fuel cycle activities were characterized. In addition, since the WG.7 assumed that all fuel cycle wastes except mill tailings are placed in a mined geologic repository, the nontransuranic wastes from several activities are included in the projections reported. The LWR fuel cycles considered are the LWR, once-through fuel cycle (Strategy 1), in which spent fuel is packaged in metal canisters and then isolated in geologic formations; and the LWR U/Pu recycle fuel cycle (Strategy 2), wherein spent fuel is reprocessed for recovery and recycle of uranium and plutonium in LWRs. The wastes projected for the two LWR fuel cycles are summarized. The reactor operations and decommissioning were found to dominate the rate of waste generation in each cycle. These activities account for at least 85% of the fuel cycle waste volume (not including head-end wastes) when normalized to per unit electrical energy generated. At 10 years out of reactor, however, spent fuel elements in Strategy 1 represent 98% of the fuel cycle activity but only 4% of the volume. Similarly, the packaged high-level waste, fuel hulls and hardware in Strategy 2 concentrate greater than 95% of the activity in 2% of the waste volume

  14. Clinical and patient reported outcomes of bleaching effectiveness.

    Klaric Sever, Eva; Budimir, Zrinka; Cerovac, Matea; Stambuk, Mario; Par, Matej; Negovetic Vranic, Dubravka; Tarle, Zrinka

    2018-01-01

    The objective of this study is to evaluate clinical and patient reported outcomes of different bleaching products. Thirty participants were randomly divided into three bleaching groups (n = 10). Bleaching was performed with high concentrations of hydrogen peroxide (HP) - Boost (40%) and Dash (30%), and with prefabricated splints Bite&White (6% HP). Tooth colour was measured before, immediately after, and 1 and 6 months after the bleaching by using classical shade guide and spectrophotometer. Tooth hypersensitivity was self-rated by patients on the Wong-Baker's face scale. Patient satisfaction was evaluated on a 7-point Likert-type scales that measured perceived performance and importance of different characteristics of bleaching treatment. All products were effective in teeth colour change (ΔE > 3.3), which was significantly higher for Boost (p = .016) and Dash (p = .024) than Bite&White treatment. Perception of hypersensitivity was the highest in Boost group, followed by Dash and Bite&White treatment. Most of the patients were satisfied with final tooth colour, length and comfort during treatment, but were dissatisfied with the stability of bleached tooth colour. Materials with the higher concentrations of bleaching agent demonstrated greater bleaching effectiveness than at-home bleaching product, but also a greater hypersensitivity. Lengthening the treatment process, but achieving a more stable tooth colour may improve the perceived value of a bleaching service.

  15. Spatial consequences of bleaching adaptation in cat retinal ganglion cells.

    Bonds, A B; Enroth-Cugell, C

    1981-01-01

    1. Experiments were conducted to study the effects of localized bleaching on the centre responses of rod-driven cat retinal ganglion cells. 2. Stimulation as far as 2 degrees from the bleaching site yielded responses which were reduced nearly as much as those generated at the bleaching site. Bleaching in the receptive field middle reduced responsiveness at a site 1 degrees peripheral more than bleaching at that peripheral site itself. 3. The effectiveness of a bleach in reducing centre responsiveness is related to the sensitivity of the region in which the bleach is applied. 4. Response reduction after a 0.2 degree bleach followed the same temporal pattern for concentric test spots of from 0.2 to 1.8 degrees in diameter, implying a substantially uniform spread of adaptation within these bounds. 5. A linear trade-off between fraction of rhodopsin and area bleached over a range of 8:1 yields the same pattern of response reduction, implying that the non-linear nature of bleaching adaptation is a property of the adaptation pool rather than independent photoreceptors. PMID:7320894

  16. Incorporating adaptive responses into future projections of coral bleaching.

    Logan, Cheryl A; Dunne, John P; Eakin, C Mark; Donner, Simon D

    2014-01-01

    Climate warming threatens to increase mass coral bleaching events, and several studies have projected the demise of tropical coral reefs this century. However, recent evidence indicates corals may be able to respond to thermal stress though adaptive processes (e.g., genetic adaptation, acclimatization, and symbiont shuffling). How these mechanisms might influence warming-induced bleaching remains largely unknown. This study compared how different adaptive processes could affect coral bleaching projections. We used the latest bias-corrected global sea surface temperature (SST) output from the NOAA/GFDL Earth System Model 2 (ESM2M) for the preindustrial period through 2100 to project coral bleaching trajectories. Initial results showed that, in the absence of adaptive processes, application of a preindustrial climatology to the NOAA Coral Reef Watch bleaching prediction method overpredicts the present-day bleaching frequency. This suggests that corals may have already responded adaptively to some warming over the industrial period. We then modified the prediction method so that the bleaching threshold either permanently increased in response to thermal history (e.g., simulating directional genetic selection) or temporarily increased for 2-10 years in response to a bleaching event (e.g., simulating symbiont shuffling). A bleaching threshold that changes relative to the preceding 60 years of thermal history reduced the frequency of mass bleaching events by 20-80% compared with the 'no adaptive response' prediction model by 2100, depending on the emissions scenario. When both types of adaptive responses were applied, up to 14% more reef cells avoided high-frequency bleaching by 2100. However, temporary increases in bleaching thresholds alone only delayed the occurrence of high-frequency bleaching by ca. 10 years in all but the lowest emissions scenario. Future research should test the rate and limit of different adaptive responses for coral species across latitudes and

  17. Mobile fission and activation products in nuclear waste disposal

    Umeki, H; Evans, N; Czervinski, K; Bruggeman, Ch; Poineau, F; Breynaert, A; Reiler, P; Pablo, J de; Pipon, Y; Molnar, M; Nishimura, T; Kienzler, B; Van Iseghem, P; Crovisier, J L; Wieland, E; Mace, N; Pablo, J de; Spahiu, K; Cui, D; Lida, Y; Charlet, L; Liu, X; Sato, H; Goutelard, F; Savoye, S; Glaus, M; Poinssot, C; Seby, F; Sato, H; Tournassat, Ch; Montavon, G; Rotenberg, B; Spahiu, K; Smith, G; Marivoet, J; Landais, P; Bruno, J; Johnson, H; Umeki, L; Geckeis, H; Giffaut, E; Grambow, B; Dierckx, A

    2007-07-01

    This document gathers 33 oral presentations that were made at this workshop dedicated to the mobility of some radionuclides in nuclear waste disposal. The workshop was organized into 6 sessions: 1) performance assessment, 2) speciation/interaction in aqueous media, 3) radioactive wastes, 4) redox processes at interfaces, 5) diffusion processes, and 6) retention processes.

  18. Mobile fission and activation products in nuclear waste disposal

    Umeki, H.; Evans, N.; Czervinski, K.; Bruggeman, Ch.; Poineau, F.; Breynaert, A.; Reiler, P.; Pablo, J. de; Pipon, Y.; Molnar, M.; Nishimura, T.; Kienzler, B.; Van Iseghem, P.; Crovisier, J.L.; Wieland, E.; Mace, N.; Pablo, J. de; Spahiu, K.; Cui, D.; Lida, Y.; Charlet, L.; Liu, X.; Sato, H.; Goutelard, F.; Savoye, S.; Glaus, M.; Poinssot, C.; Seby, F.; Sato, H.; Tournassat, Ch.; Montavon, G.; Rotenberg, B.; Spahiu, K.; Smith, G.; Marivoet, J.; Landais, P.; Bruno, J.; Johnson, H.; Umeki, L.; Geckeis, H.; Giffaut, E.; Grambow, B.; Dierckx, A.

    2007-01-01

    This document gathers 33 oral presentations that were made at this workshop dedicated to the mobility of some radionuclides in nuclear waste disposal. The workshop was organized into 6 sessions: 1) performance assessment, 2) speciation/interaction in aqueous media, 3) radioactive wastes, 4) redox processes at interfaces, 5) diffusion processes, and 6) retention processes

  19. Waste production and regional growth of marine activities an econometric model.

    Bramati, Maria Caterina

    2016-11-15

    Coastal regions are characterized by intense human activity and climatic pressures, often intensified by competing interests in the use of marine waters. To assess the effect of public spending on the regional economy, an econometric model is here proposed. Not only are the regional investment and the climatic risks included in the model, but also variables related to the anthropogenic pressure, such as population, economic activities and waste production. Feedback effects of economic and demographic expansion on the pollution of coastal areas are also considered. It is found that dangerous waste increases with growing shipping and transportation activities and with growing population density in non-touristic coastal areas. On the other hand, the amount of non-dangerous wastes increases with marine mining, defense and offshore energy production activities. However, lower waste production occurs in areas where aquaculture and touristic industry are more exploited, and accompanied by increasing regional investment in waste disposal. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Immobilized low-activity waste interim storage facility, Project W-465 conceptual design report

    Pickett, W.W.

    1997-12-30

    This report outlines the design and Total Estimated Cost to modify the four unused grout vaults for the remote handling and interim storage of immobilized low-activity waste (ILAW). The grout vault facilities in the 200 East Area of the Hanford Site were constructed in the 1980s to support Tank Waste disposal activities. The facilities were to serve project B-714 which was intended to store grouted low-activity waste. The existing 4 unused grout vaults, with modifications for remote handling capability, will provide sufficient capacity for approximately three years of immobilized low activity waste (ILAW) production from the Tank Waste Remediation System-Privatization Vendors (TWRS-PV). These retrofit modifications to the grout vaults will result in an ILAW interim storage facility (Project W465) that will comply with applicable DOE directives, and state and federal regulations.

  1. Immobilized low-activity waste interim storage facility, Project W-465 conceptual design report

    Pickett, W.W.

    1997-01-01

    This report outlines the design and Total Estimated Cost to modify the four unused grout vaults for the remote handling and interim storage of immobilized low-activity waste (ILAW). The grout vault facilities in the 200 East Area of the Hanford Site were constructed in the 1980s to support Tank Waste disposal activities. The facilities were to serve project B-714 which was intended to store grouted low-activity waste. The existing 4 unused grout vaults, with modifications for remote handling capability, will provide sufficient capacity for approximately three years of immobilized low activity waste (ILAW) production from the Tank Waste Remediation System-Privatization Vendors (TWRS-PV). These retrofit modifications to the grout vaults will result in an ILAW interim storage facility (Project W465) that will comply with applicable DOE directives, and state and federal regulations

  2. Spanish experience in managing low and intermediate activity radioactive wastes

    Granero, J.J.

    1986-01-01

    The Spanish experience in management of low and intermediated level radioactive wastes is presented. The radioactive wastes stored come from research reactors, nuclear power plants, nuclear fuel cycle, scientific research, radiodiagnostic and medical applications. The commonest method is incorporation in cement inside special drums, even though some facilities use processes based on urea formal dehyde and on asphalt. Transport of the wastes is carried out by private undertakings and the Nuclear Energy Board. The sites used for storing are temporary in nature. The wastes produced by nuclear power plants are stored on site, with those processed by the Nuclear Energy Board are taken to a province of Cordoba. The National Company ENRESA for managing of all kinds of wastes was created. The Spanish legislation on this subject and the research being carried out by Spain itself and in cooperation with other States, are described. (Author) [pt

  3. Decision for counting condition of radioactive waste activities measuring by Ludlum detector

    Bambang-Purwanto

    2000-01-01

    Radioactive waste must measured for activities before be throw out to environment. Measuring will be important in ordered to know activities can be given management direction. For activities radioactive waste on limit threshold value must processed, but for under limit threshold value activities can be throw out to environment. Activities measuring for solid radioactive waste and liquid by (Total, β, γ) Ludlum detector connected Mode-1000 Scaler Counting. Before measuring for solid waste activities was decisioned optimally counting condition, and be obtained are : sample weight 3.5 gram, heating temperature of 125 o C and heating time at 60 minutes. Activities measuring result by total detector ranges from (0.68-0.71) 10 -1 μCi/gram, β detector ranges from (0.24-0.25) 10 -1 μCi/gram and γ detector ranges from (0.35-0.37) μCi/gram

  4. A treatment station for solid radio-active waste at the Saclay nuclear research centre (1962)

    Cerre, P.; Mestre, E.; Lebrun, P.

    1962-01-01

    The waste from an atomic centre is very varied in nature, in form, and in activity, going from weakly contaminated laboratory waste to objects actuated in a pile and strongly radioactive. After one year's working of a pilot plant, a factory has been built, in which solide waste is treated and then conditioned in concrete blocks. The present communication describes the treatment and conditioning techniques in this factory which uses to a maximum remotely controlled operation. (authors) [fr

  5. Comparative clinical study of the effectiveness of different dental bleaching methods - two year follow-up

    Rafael Francisco Lia Mondelli

    2012-08-01

    Full Text Available This study evaluated color change, stability, and tooth sensitivity in patients submitted to different bleaching techniques. MATERIAL AND METHODS: In this study, 48 patients were divided into five groups. A half-mouth design was conducted to compare two in-office bleaching techniques (with and without light activation: G1: 35% hydrogen peroxide (HP (Lase Peroxide - DMC Equipments, São Carlos, SP, Brazil + hybrid light (HL (LED/Diode Laser, Whitening Lase II DMC Equipments, São Carlos, SP, Brazil; G2: 35% HP; G3: 38% HP (X-traBoost - Ultradent, South Jordan UT, USA + HL; G4: 38% HP; and G5: 15% carbamide peroxide (CP (Opalescence PF - Ultradent, South Jordan UT, USA. For G1 and G3, HP was applied on the enamel surface for 3 consecutive applications activated by HL. Each application included 3x3' HL activations with 1' between each interval; for G2 and G4, HP was applied 3x15' with 15' between intervals; and for G5, 15% CP was applied for 120'/10 days at home. A spectrophotometer was used to measure color change before the treatment and after 24 h, 1 week, 1, 6, 12, 18 and 24 months. A VAS questionnaire was used to evaluate tooth sensitivity before the treatment, immediately following treatment, 24 h after and finally 1 week after. RESULTS: Statistical analysis did not reveal any significant differences between in-office bleaching with or without HL activation related to effectiveness; nevertheless the time required was less with HL. Statistical differences were observed between the results after 24 h, 1 week and 1, 6, 12, 18 and 24 months (intergroup. Immediately, in-office bleaching increased tooth sensitivity. The groups activated with HL required less application time with gel. CONCLUSION: All techniques and bleaching agents used were effective and demonstrated similar behaviors.

  6. Distribution of the active liquid waste discharge concentration

    Chan, A.H.C.

    1985-03-01

    In assessing the proposal for removing the on-line liquid effluent monitor (LEM) from the Darlington NGS-A design, it was required to estimate the probability that the concentration of β-y emitters in the active liquid waste (ALW) tank discharges exceeds a specified level. To achieve this, it was necessary to know the underlying distribution of the ALW discharge concentration. Since the distribution could only be estimated from the historical data, it was also important to provide the confidence interval for the estimated probability. Using the ALW discharge records of Pickering and Bruce NGS-A, it was found that the log-normal distribution provided the best fit for the data. The frequency of the tank concentration exceeding the specified level of 24000μCi/m 3 was estimated to be 1 in 200,000 years at Bruce NGS-A and 1 in 100,000 years at Pickering. The 99% upper confidence limits are 1 in 2777 years and 1 in 77 years, respectively

  7. Nitrogen in the Process of Waste Activated Sludge Anaerobic Digestion

    Suschka Jan

    2014-07-01

    Full Text Available Primary or secondary sewage sludge in medium and large WWTP are most often processed by anaerobic digestion, as a method of conditioning, sludge quantity minimization and biogas production. With the aim to achieve the best results of sludge processing several modifications of technologies were suggested, investigated and introduced in the full technical scale. Various sludge pretreatment technologies before anaerobic treatment have been widely investigated and partially introduced. Obviously, there are always some limitations and some negative side effects. Selected aspects have been presented and discussed. The problem of nitrogen has been highlighted on the basis of the carried out investigations. The single and two step - mesophilic and thermophilic - anaerobic waste activated sludge digestion processes, preceded by preliminary hydrolysis were investigated. The aim of lab-scale experiments was pre-treatment of the sludge by means of low intensive alkaline and hydrodynamic disintegration. Depending on the pretreatment technologies and the digestion temperature large ammonia concentrations, up to 1800 mg NH4/dm3 have been measured. Return of the sludge liquor to the main sewage treatment line means additional nitrogen removal costs. Possible solutions are discussed.

  8. Radioactivity evaluation method for pre-packed concrete packages of low-level dry active wastes

    Sakai, Toshiaki; Funahashi, Tetsuo; Watabe, Kiyomi; Ozawa, Yukitoshi; Kashiwagi, Makoto

    1998-01-01

    Low-level dry active wastes of nuclear power plants are grouted with cement mortal in a container and planned to disposed into the shallow land disposal site. The characteristics of radionuclides contained in dry active wastes are same as homogeneous solidified wastes. In the previous report, we reported the applicability of the radioactivity evaluation methods established for homogeneous solidified wastes to pre-packed concrete packages. This report outlines the developed radioactivity evaluation methods for pre-packed concrete packages based upon recent data. Since the characteristics of dry active wastes depend upon the plant system in which dry active wastes originate and the types of contamination, sampling of wastes and activity measurement were executed to derive scaling factors. The radioactivity measurement methods were also verified. The applicability of non-destructive methods to measure radioactivity concentration of pre-packed concrete packages was examined by computer simulation. It is concluded that those methods are accurate enough to measure actual waste packages. (author)

  9. Wastes

    Bovard, Pierre

    The origin of the wastes (power stations, reprocessing, fission products) is determined and the control ensuring the innocuity with respect to man, public acceptance, availability, economics and cost are examined [fr

  10. Laboratory Evaporation Testing Of Hanford Waste Treatment Plant Low Activity Waste Off-Gas Condensate Simulant

    Adamson, Duane J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, Charles A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, Daniel J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Crawford, Charles L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Wilmarth, William R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2014-01-01

    The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream, LAW Off-Gas Condensate, from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable de-coupled operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also decrease the LAW vitrification mission duration and quantity of canistered glass waste forms. This LAW Off-Gas Condensate stream contains components that are volatile at melter temperatures and are problematic for the glass waste form. Because this stream recycles within WTP, these components accumulate in the Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to be within acceptable concentration ranges in the LAW glass. Diverting the stream reduces the halides in the recycled Condensate and is a key outcome of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, identifying a disposition path becomes vitally important. This task examines the impact of potential future disposition of this stream in the Hanford tank farms, and investigates auxiliary evaporation to enable another disposition path. Unless an auxiliary evaporator is used, returning the stream to the tank farms would require evaporation in the 242-A evaporator. This stream is expected to be unusual because it will be very high in corrosive species that are volatile in the melter

  11. Laboratory Evaporation Testing Of Hanford Waste Treatment Plant Low Activity Waste Off-Gas Condensate Simulant

    Adamson, Duane J.; Nash, Charles A.; McCabe, Daniel J.; Crawford, Charles L.; Wilmarth, William R.

    2014-01-01

    The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream, LAW Off-Gas Condensate, from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable de-coupled operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also decrease the LAW vitrification mission duration and quantity of canistered glass waste forms. This LAW Off-Gas Condensate stream contains components that are volatile at melter temperatures and are problematic for the glass waste form. Because this stream recycles within WTP, these components accumulate in the Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to be within acceptable concentration ranges in the LAW glass. Diverting the stream reduces the halides in the recycled Condensate and is a key outcome of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, identifying a disposition path becomes vitally important. This task examines the impact of potential future disposition of this stream in the Hanford tank farms, and investigates auxiliary evaporation to enable another disposition path. Unless an auxiliary evaporator is used, returning the stream to the tank farms would require evaporation in the 242-A evaporator. This stream is expected to be unusual because it will be very high in corrosive species that are volatile in the melter

  12. [Complications of cosmetic skin bleaching in Africa].

    Morand, J J; Ly, F; Lightburn, E; Mahé, A

    2007-12-01

    Use of cosmetic products to bleach or lighten the skin is common among dark-skinned women in some sub-Saharan African countries. Long-term use of some pharmacologic compounds (e.g. hydroquinone, glucocorticoids and mercury) can cause adverse effects including dermatologic disorders such as dyschromia, exogenous ochronosis, acne and hypertrichosis, prominent striae, tinea corporis, pyoderma, erysipelas, scabies, and contact dermatitis and systemic complications such as hypertension, hypercorticism or surrenal deficiency, and mercurial nephropathy.

  13. Radioprotection and physical surveillance during activities of liquid wastes of high and low activity in italian ITREC plant

    Petagna, Edoardo; Tortorelli, Pietro

    1997-03-01

    Many studies were made in ITREC Plant, located in ENEA - Trisaia Research Center, in the field of the nuclear fuel reprocessing, in the past years. During these activities liquid wastes of high and low activity were yielded and stored in the special area of tanks named Waste-1. In order to condition the low activity liquid wastes, essentially fission products, beta and gamma emitters, was built the SIRTE Plant (Integrate System for the Raise and Effluents Treatment) based on cementation process. In the present work, the radiological monitoring performed within the plant during the first campaign of cementation, is showed

  14. Preparation of activated Carbons from extracted waste biomass by chemical activation

    Toteva, V.; Nickolov, R.

    2013-01-01

    Full text: Novel biomass precursors for the production of activated carbons (ACs) were studied. ACs were prepared from extracted coffee husks and extracted spent ground coffee - separately or as mixtures with 10, 20 and 30 mass % Bulgarian lignite coal. Activation by potassium hydroxide was employed for all samples. The results obtained show that the surface and porous parameters of the ACs depend on the nature of the initial materials used. The specific surface areas (BET) and the microporosities of ACs obtained from extracted spent ground coffee mixed with 20 mass % Bulgarian lignite coals, are greater than those of the ACs from extracted coffee husks. It is likely that the reason for this result is the chemical composition of the precursors. The coffee husks have less lignin and more holocellulose. The latter undergoes more significant destructive changes in the process of chemical activation. On the contrary, waste ground coffee precursors contain more lignin and less holocellulose. As a result, after the chemical activation, the carbons prepared from extracted spent ground coffee exhibit better porous parameters and higher specific surface areas. key words: activated carbons, extraction, waste biomass

  15. Sodium Hydroxide and Calcium Hydroxide Hybrid Oxygen Bleaching with System

    Doelle, K.; Bajrami, B.

    2018-01-01

    This study investigates the replacement of sodium hydroxide in the oxygen bleaching stage using a hybrid system consisting of sodium hydroxide calcium hydroxide. Commercial Kraft pulping was studied using yellow pine Kraft pulp obtained from a company in the US. The impact of sodium hydroxide, calcium hydroxide hybrid system in regard to concentration, reaction time and temperature for Kraft pulp was evaluated. The sodium hydroxide and calcium hydroxide dosage was varied between 0% and 15% based on oven dry fiber content. The bleaching reaction time was varied between 0 and 180 minutes whereas the bleaching temperature ranged between 70 °C and 110 °C. The ability to bleach pulp was measured by determining the Kappa number. Optimum bleaching results for the hybrid system were achieved with 4% sodium hydroxide and 2% calcium hydroxide content. Beyond this, the ability to bleach pulp decreased.

  16. Thermoluminescence emission spectra and optical bleaching of oligoclase

    Bos, A.J.J.; Piters, T.M.; Ypma, P.J.

    1994-01-01

    Thermoluminescence (TL) spectra of oligoclase samples have been recorded in the temperature range from 300 to 700 K and the wavelength range from 300 to 850 nm. Like other feldspars, oligoclase produces blue (peaking at 460 nm) and red (peaking at 765 nm) emission bands. The maximum of the red emission occurs 20 K lower than that of the blue band. Optical bleaching was performed at wavelengths varying from 360 to 800 nm. Bleaching of artificially irradiated oligoclase causes a decrease of the TL signal. The bleaching efficiency increases with decreasing wavelength. Bleaching does not only influence the height of the glow curve but also the shape. An interesting observation is that the ratio of the blue and red band intensities is not affected by a bleaching procedure. No evidence has been found that bleaching influences the shape of the emission spectra. The correlation between the blue and red bands is discussed. (Author)

  17. Overview of DOE LLWMP waste treatment, packaging, and handling activities

    Pechin, W.H.

    1982-01-01

    The program objective is to develop the best available technology for waste treatment, packaging, and handling to meet the needs of shallow land burial disposal and for greater confinement than shallow land burial. The program has reviewed many of the hardware options for appropriate usage with low-level waste, but promising options remain to be evaluated. The testing of treatment technologies with actual radioactive process wastes has been initiated. The analysis of the interaction of treatment, solidification and disposal needs to be completed

  18. Participation of the ININ in the activities of radioactive waste management of the Laguna Verde Central

    Medrano L, M.; Rodriguez C, C.; Linares R, D.; Ramirez G, R.; Zarate M, N.

    2006-01-01

    From the beginning of the operation of the Laguna Verde Central (CLV) the National Institute of Nuclear Research (ININ) has come supporting the CLV in the activities of administration of the humid and dry radioactive waste generated by the operation of the two units of the CLV, from the elaboration of procedures to the temporary storage in site, the implementation of a program of minimization and segregation of dry solid wastes, until the classification of the lots of humid waste and bulk dry wastes. In this work the description of the management activities of radioactive wastes carried out by the ININ in the facilities of the CLV to the date is presented, as well as some actions that they are had drifted in the future near, among those that it stands out the determination of the total alpha activity in humid samples by means of scintillation analysis. (Author)

  19. Cultivation of phagotrophic algae with waste activated sludge as a fast approach to reclaim waste organics.

    Li, Cong; Xiao, Suo; Ju, Lu-Kwang

    2016-03-15

    Substantial energy is reserved in waste activated sludge (WAS) organics but much of it is difficult to recover because the solid organics require long time to solubilize. In this work we introduced the new approach of recovering WAS organics into the biomass of phagotrophic algae. Phagotrophic algae have the unique ability to grow by ingesting insoluble organic particles including microbial cells. This phagotrophic ability renders the solubilization of WAS organics unnecessary and makes this approach remarkably fast. The approach consists of two stages: a short anaerobic digestion treatment followed by the algal growth on treated WAS. The short anaerobic digestion was exploited to release discrete bacteria from WAS flocs. Phagotrophic algae could then grow rapidly with the released bacteria as well as the solubilized nutrients in the treated WAS. The results showed that WAS organics could be quickly consumed by phagotrophic algae. Among all studied conditions the highest WAS volatile solids (VS) reduction was achieved with 72 h anaerobic digestion and 24 h algal growth. In this optimal process, 28% of WAS VS was reduced, and 41% and 20% of the reduced VS were converted into algal biomass and lipids, respectively. In comparison, only 18% WAS VS were reduced after the same time of aerobic digestion without algae addition. Through this approach, the amount of WAS organics requiring further treatment for final disposal is significantly reduced. With the production of significant amounts of algal biomass and lipids, WAS treatment is expected to be more economical and sustainable in material recycling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. 40 CFR 260.41 - Procedures for case-by-case regulation of hazardous waste recycling activities.

    2010-07-01

    ... of hazardous waste recycling activities. 260.41 Section 260.41 Protection of Environment... Rulemaking Petitions § 260.41 Procedures for case-by-case regulation of hazardous waste recycling activities... hazardous waste recycling activities described in § 261.6(a)(2)(iii) under the provisions of § 261.6 (b) and...

  1. The management of low activity radioactive waste: IAEA guidance and perspectives

    Louvat, D.; Rowat, J.H.; Potier, J.M.

    2005-01-01

    This paper describes the safety standards and reports of the International Atomic Energy Agency (IAEA) applicable to the management and disposal of low activity radioactive waste and provides some historical perspective on their development. Some of the most important current issues in the area of low activity radioactive waste management are discussed in the context of related ongoing IAEA activities. At the end of the paper, a number of issues and questions are raised for consideration and discussion at this symposium. (author)

  2. A global protocol for monitoring of coral bleaching

    Oliver, J.; Setiasih, N.; Marshall, P.; Hansen, L.

    2004-01-01

    Coral bleaching and subsequent mortality represent a major threat to the future health and productivity of coral reefs. However a lack of reliable data on occurrence, severity and other characteristics of bleaching events hampers research on the causes and consequences of this important phenomenon. This article describes a global protocol for monitoring coral bleaching events, which addresses this problem and can be used by people with different levels of expertise and resources.

  3. Mass Coral Bleaching in 2010 in the Southern Caribbean

    Alemu I, Jahson Berhane; Clement, Ysharda

    2014-01-01

    Ocean temperatures are increasing globally and the Caribbean is no exception. An extreme ocean warming event in 2010 placed Tobago's coral reefs under severe stress resulting in widespread coral bleaching and threatening the livelihoods that rely on them. The bleaching response of four reef building taxa was monitored over a six month period across three major reefs systems in Tobago. By identifying taxa resilient to bleaching we propose to assist local coral reef managers in the decision mak...

  4. Coral mass bleaching and reef temperatures at Navassa Island, 2006

    Miller, M. W.; Piniak, G. A.; Williams, D. E.

    2011-01-01

    Bleaching and associated mortality is an extreme threat to the persistence of coral populations in the projected warming regime of the next few decades. Recent evidence indicates that thermal bleaching thresholds may be affected by water quality gradients. The unexpected encounter of a coral mass bleaching event at a remote, uninhabited Caribbean island (Navassa) during a routine reef assessment cruise in November 2006 provided the opportunity to characterize bleaching responses and thermal exposure in an oceanic area with negligible continental influence or human impact on water quality. The coral taxa most susceptible to bleaching were Agaricia spp. and Montastraea faveolata. Siderastraea siderea, Diploria spp. and Porites porites were intermediately affected, while Porites astreoides and Montastraea cavernosa were minimally affected and negligible bleaching was observed in Acropora palmata. Bleaching prevalence (colonies > 4 cm diameter) ranged from 0.16 to 0.63 among sites. Deeper sites (between 18 and 37 m) had significantly higher prevalence of bleaching than shallow sites (<10 m). This general pattern of more bleaching in deeper sites also occurred within species. Though exposure to high-temperature stress was not greater at deeper sites, water motion, which may bolster bleaching resistance, was likely less. In situ loggers indicated temperatures over 30 °C initiated at shallow sites in mid-August, at deeper sites in early September, and were persistent at all sites until mid-October. Long term (1983-2007) climatologies constructed from AVHRR SSTs suggest that the mass bleaching event observed at Navassa in 2006 corresponded with greater intensity and duration of warm temperature anomalies than occurred in 2005, for which no in situ observations (bleaching nor temperature) are available.

  5. Capability and limitation study of the DDT passive-active neutron waste assay instrument

    Nicholas, N.J.; Coop, K.L.; Estep, R.J.

    1992-05-01

    The differential-dieaway-technique passive-active neutron assay system is widely used by transuranic waste generators to certify their drummed waste for eventual shipment to the Waste Isolation Pilot Plant (WIPP). Stricter criteria being established for waste emplacement at the WIPP site has led to a renewed interest in improvements to and a better understanding of current nondestructive assay (NDA) techniques. Our study includes the effects of source position, extreme matrices, high neutron backgrounds, and source self-shielding to explore the system's capabilities and limitations and to establish a basis for comparison with other NDA systems. 11 refs

  6. Nondestructive assay of TRU waste using gamma-ray active and passive computed tomography

    Roberson, G.P.; Decman, D.; Martz, H.; Keto, E.R.; Johansson, E.M.

    1995-01-01

    The authors have developed an active and passive computed tomography (A and PCT) scanner for assaying radioactive waste drums. Here they describe the hardware components of their system and the software used for data acquisition, gamma-ray spectroscopy analysis, and image reconstruction. They have measured the performance of the system using ''mock'' waste drums and calibrated radioactive sources. They also describe the results of measurements using this system to assay a real TRU waste drum with relatively low Pu content. The results are compared with X-ray NDE studies of the same TRU waste drum as well as assay results from segmented gamma scanner (SGS) measurements

  7. Quarterly Progress Report Research And Development Activities Waste Fixation Program October Through December 1976

    McElroy, J. L.

    1977-01-01

    Research and development activities of the Waste Fixation Program for October through December 1976 are described in this report. The objective of this program is to develop processes to convert high-level radioactive liquid waste (HLLW) to solid forms that are demonstrated to be physically, chemically, and radiolytically stable and inert. The scope of this program encompasses plans to make available a flexible advancing technology for the solidification of radioactive waste. Early technology will produce borosilicate glass by in-can melting and continuous electric melters. Multibarrier waste forms will be developed for future application

  8. Assessment of allowable transuranic activity levels for WIPP wastes

    1987-12-01

    This study provides a technical evaluation for the establishment of an upper limit on the transuranic content of waste packages to be received. To accomplish this, the predicted radiological performance of WIPP is compared to the radiological performance requirements applicable to WIPP. These performance requirements include radiation protection standards for both routine facility operations and credible operational accidents. These requirements are discussed in Chapter 2.0. From the margin between predicted performance and the performance requirements, the maximum allowable transuranic content of waste packages can then be inferred. Within the resulting compliance envelope, a waste acceptance criterion can be established that delineates the allowable level of transuranic radioactivity content for contact handled (CH) and remote handled (RH) waste packages. 13 refs., 8 tabs

  9. Adsorption of Safranin-T from wastewater using waste materials- activated carbon and activated rice husks.

    Gupta, Vinod K; Mittal, Alok; Jain, Rajeev; Mathur, Megha; Sikarwar, Shalini

    2006-11-01

    Textile effluents are major industrial polluters because of high color content, about 15% unfixed dyes and salts. The present paper is aimed to investigate and develop cheap adsorption methods for color removal from wastewater using waste materials activated carbon and activated rice husk-as adsorbents. The method was employed for the removal of Safranin-T and the influence of various factors such as adsorbent dose, adsorbate concentration, particle size, temperature, contact time, and pH was studied. The adsorption of the dye over both the adsorbents was found to follow Langmuir and Freundlich adsorption isotherm models. Based on these models, different useful thermodynamic parameters have been evaluated for both the adsorption processes. The adsorption of Safranin-T over activated carbon and activated rice husks follows first-order kinetics and the rate constants for the adsorption processes decrease with increase in temperature.

  10. Glass-crystalline materials for active waste incorporation

    Kulichenko, V.V.; Krylova, N.V.; Vlasov, V.I.; Polyakov, A.S.

    1979-01-01

    This paper presents the results of investigations into the possibility and conditions for using glass-crystalline materials for the incorporation of radionuclides. Materials of a cast pyroxene type that are obtained by smelting calcined wastes with acid blast furnace slags are described. A study was also made of materials of a basalt type prepared from wastes with and without alkali metal salt. Changes in the structure and properties of materials in the process of storage at different temperatures have been studied

  11. Determination of alpha activity and fissile mass content in solid waste by systems using neutron interrogation

    Romeyer Dherbey, J.; Lacruche, G.; Berne, R.; Auge, J.; Martin Deidier, L.; Butez, M.

    1990-01-01

    The Quantitative control (determination of heavy nuclides and alpha activity) of alpha radioactive wastes is necessary, particularly to determine if the waste is in accordance with the surface storage limits. In order to reduce the uncertainty on the alpha activity resulting from unknown isotopic composition, inhomogeneity of heavy nuclides in the matrix, combination of several methods is necessary. In the paper we present the Cadarache development work in the NDA of solid waste using the Californium shuffler, 14 Mev neutron generator, and also passive techniques such as neutron emission measurement and gamma spectrometry. Experimental systems combining active and passive methods are presented (COSAC, BANCO, DANAIDE, PROMETHEE)

  12. Effects of ozonation on disinfection and microbial activity in waste activated sludge for land application

    Ahn, Kyu-Hong; Maeng, Sung Kyu; Hong, Jun-Seok; Lim, Byung-Ran

    2003-07-01

    Effects of ozonation on microbial biomass activity and community structure in waste activated sludges from various treatment plants were investigated. The densities of viable cells and microbial community structure in the sludges treated with ozone at 0.1, 0.2 and 0.4 gO{sub 3}/gDS were measured on the basis of the respiratory quinone profile and LIVE/DEAD Backlight(TM). The results from the bacterial concentration and quinone profiles of the waste activated sludge showed that respiratory activities of microorganisms were detected at the ozone dose of 0.4 gO{sub 3}/gDS. However, fecal coliform, fecal streptococcus and Salmonella sp. in the ozonized sludge were not detected. This result implies that some microorganisms might be more tolerant to ozonation than the pathogenic indicators. The pathogens reduction requirements for Class A biosolids were still met by the ozonation at 0.4 gO{sub 3}/gDS.

  13. Mass coral bleaching in 2010 in the southern Caribbean.

    Alemu I, Jahson Berhane; Clement, Ysharda

    2014-01-01

    Ocean temperatures are increasing globally and the Caribbean is no exception. An extreme ocean warming event in 2010 placed Tobago's coral reefs under severe stress resulting in widespread coral bleaching and threatening the livelihoods that rely on them. The bleaching response of four reef building taxa was monitored over a six month period across three major reefs systems in Tobago. By identifying taxa resilient to bleaching we propose to assist local coral reef managers in the decision making process to cope with mass bleaching events. The bleaching signal (length of exposure to high ocean temperatures) varied widely between the Atlantic and Caribbean reefs, but regardless of this variation most taxa bleached. Colpophyllia natans, Montastraea faveolata and Siderastrea siderea were considered the most bleaching vulnerable taxa. Interestingly, reefs with the highest coral cover showed the greatest decline reef building taxa, and conversely, reefs with the lowest coral cover showed the most bleaching but lowest change in coral cover with little algal overgrowth post-bleaching.

  14. Coral bleaching at Little Cayman, Cayman Islands 2009

    van Hooidonk, Ruben J.; Manzello, Derek P.; Moye, Jessica; Brandt, Marilyn E.; Hendee, James C.; McCoy, Croy; Manfrino, Carrie

    2012-06-01

    The global rise in sea temperature through anthropogenic climate change is affecting coral reef ecosystems through a phenomenon known as coral bleaching; that is, the whitening of corals due to the loss of the symbiotic zooxanthellae which impart corals with their characteristic vivid coloration. We describe aspects of the most prevalent episode of coral bleaching ever recorded at Little Cayman, Cayman Islands, during the fall of 2009. The most susceptible corals were found to be, in order, Siderastrea siderea, Montastraea annularis, and Montastraea faveolata, while Diplora strigosa and Agaricia spp. were less so, yet still showed considerable bleaching prevalence and severity. Those found to be least susceptible were Porites porites, Porites astreoides, and Montastraea cavernosa. These observations and other reported observations of coral bleaching, together with 29 years (1982-2010) of satellite-derived sea surface temperatures, were used to optimize bleaching predictions at this location. To do this a Degree Heating Weeks (DHW) and Peirce Skill Score (PSS) analysis was employed to calculate a local bleaching threshold above which bleaching was expected to occur. A threshold of 4.2 DHW had the highest skill, with a PSS of 0.70. The method outlined here could be applied to other regions to find the optimal bleaching threshold and improve bleaching predictions.

  15. Regeneration of irradiated optical fibres by photo-bleaching?

    Henschel, H.; Koehn, O.

    1999-01-01

    It is known that a light power between 0,1 and 20 μW caused bleaching of colour centres, which implies a reduction of induced loss. Older fibres especially those with a core made of undoped, low OH silica, experience tremendous photo-bleaching. Light of shorter wavelengths has a higher bleaching efficiency than that of longer wavelengths and same light intensity. The investigations have demonstrated that the injection of photo-bleaching light of shorter wavelength and higher intensity can distinctly decrease the radiation-induced loss of Ge-doped fibres, especially at low temperatures. Another possibility to apply photo-bleaching by short wavelength is to regenerate fibres that are permanently installed in radiation environments. Modern undoped multi-mode (MM) step index (Si), Ge-doped MM graded index (Gi) and Ge-doped single-mode (SM) fibres that had been irradiated were submitted to bleaching light. In this article it is shown how loss reduction and necessary bleaching time depend on wavelength and intensity of the bleaching light, on fibre length (bleaching time) and on radiation dose. These results are promising for the regeneration of optical fibres in facilities where the fibres cannot be replaced easily by new ones. (A.C.)

  16. Coral community response to bleaching on a highly disturbed reef.

    Guest, J R; Low, J; Tun, K; Wilson, B; Ng, C; Raingeard, D; Ulstrup, K E; Tanzil, J T I; Todd, P A; Toh, T C; McDougald, D; Chou, L M; Steinberg, P D

    2016-02-15

    While many studies of coral bleaching report on broad, regional scale responses, fewer examine variation in susceptibility among coral taxa and changes in community structure, before, during and after bleaching on individual reefs. Here we report in detail on the response to bleaching by a coral community on a highly disturbed reef site south of mainland Singapore before, during and after a major thermal anomaly in 2010. To estimate the capacity for resistance to thermal stress, we report on: a) overall bleaching severity during and after the event, b) differences in bleaching susceptibility among taxa during the event, and c) changes in coral community structure one year before and after bleaching. Approximately two thirds of colonies bleached, however, post-bleaching recovery was quite rapid and, importantly, coral taxa that are usually highly susceptible were relatively unaffected. Although total coral cover declined, there was no significant change in coral taxonomic community structure before and after bleaching. Several factors may have contributed to the overall high resistance of corals at this site including Symbiodinium affiliation, turbidity and heterotrophy. Our results suggest that, despite experiencing chronic anthropogenic disturbances, turbid shallow reef communities may be remarkably resilient to acute thermal stress.

  17. Mass Coral Bleaching in 2010 in the Southern Caribbean

    Alemu I, Jahson Berhane; Clement, Ysharda

    2014-01-01

    Ocean temperatures are increasing globally and the Caribbean is no exception. An extreme ocean warming event in 2010 placed Tobago's coral reefs under severe stress resulting in widespread coral bleaching and threatening the livelihoods that rely on them. The bleaching response of four reef building taxa was monitored over a six month period across three major reefs systems in Tobago. By identifying taxa resilient to bleaching we propose to assist local coral reef managers in the decision making process to cope with mass bleaching events. The bleaching signal (length of exposure to high ocean temperatures) varied widely between the Atlantic and Caribbean reefs, but regardless of this variation most taxa bleached. Colpophyllia natans, Montastraea faveolata and Siderastrea siderea were considered the most bleaching vulnerable taxa. Interestingly, reefs with the highest coral cover showed the greatest decline reef building taxa, and conversely, reefs with the lowest coral cover showed the most bleaching but lowest change in coral cover with little algal overgrowth post-bleaching. PMID:24400078

  18. Arundo donax L. reed: new perspectives for pulping and bleaching. Part 4. Peroxide bleaching of organosolv pulps.

    Shatalov, A A; Pereira, H

    2005-05-01

    A comparative study on TCF (totally chlorine-free) bleachability of organosolv pulps from the annual fibre crop Arundo donax L. (giant reed) was carried out using a simple three-stage peroxide bleaching sequence without oxygen pre-bleaching. ASAM (alkali-sulfite-anthraquinone-methanol), Organocell (alkali-anthraquinone-methanol) and ethanol-soda organosolv pulps were bleached and compared with kraft pulp, as a reference. The final brightness of 76-78% ISO was attained for all tested pulps. The chemical charge required to reach this level of brightness varied for different pulps (despite the equal initial content of the residual lignin) and directly related to starting brightness values. No direct correlation between brightness improvement and lignin removal during bleaching was found, indicating the influence of the specific pulp properties introduced by pulping process on bleaching chemistry. The general higher bleaching response of organosolv pulps from A. donax was noted in comparison with kraft.

  19. The safety of high activity long life nuclear waste

    Devillers, Ch.

    1998-01-01

    The article concerns the deep geological storage for managing high activity long life nuclear waste. He puts forward a context giving a structure to the discussions of those involved concerning an assessment of the safety of a deep geological deposit project. Three main aspects are put forward. The risks for future generations and the time scales to be considered: briefly, the deposit needs to satisfy two functions for protecting man and the environment, namely firstly isolating high activity radionuclides from the biosphere during the time required for their radioactive decay (about ten thousands years), and secondly delay and dilute long life radionuclides without any a priori time limit so as to reduce their effects in the biosphere to extremely low levels. The risks are linked to possible failures of the containment barriers whose causes need to be analysed and be provided against by suitable provisions concerning their design. The definition of these design provisions requires an in depth examination of uncertain elements. The main causes of uncertainty are listed according to the scale of time in question, that is O-10,000 years, 10,000-100,000 years and beyond 100,000 years, stressing the importance of selecting a stable geological site and more generally a solid concept that is not very sensitive in uncertainties. Beyond 100,000 years the extent of uncertainties no longer makes it possible to make realistic predictions. It is thus necessary to consider the alternative scenarios concerning geological and climatic changes and the corresponding increasing risks of radionuclides. The risks in question may be relativized by realizing that on this time scale, the residual activities of soluble and insoluble alpha and beta emitters are comparable to those of a storage centre located on the surface at the end of the monitoring period. Finally, the article considers the approach put forward concerning the safety of a deep geological storage advocated by the French

  20. Characterization of hazardous waste residuals from Environmental Restoration Program activities at DOE installations: Waste management implications

    Lazaro, M.A.; Esposito, M.P.

    1995-01-01

    Investigators at Argonne National Laboratory (ANL), with support from associates at the Pacific Northwest Laboratory (PNL), have assembled an inventory of the types and volumes of radioactive, toxic or hazardous, and mixed waste likely to be generated over the next 30 years as the US Department of Energy (DOE) implements its nationwide Environmental Restoration (ER) Program. The inventory and related analyses are being considered for integration into DOE's Programmatic Environmental Impact Statement (PEIS) covering the potential environmental impacts and risks associated with alternative management practices and programs for wastes generated from routine operations. If this happens, the ER-generated waste could be managed under a set of alternatives considered under the PEIS and selected at the end of the current National Environmental Policy Act process

  1. Aged refuse enhances anaerobic digestion of waste activated sludge.

    Zhao, Jianwei; Gui, Lin; Wang, Qilin; Liu, Yiwen; Wang, Dongbo; Ni, Bing-Jie; Li, Xiaoming; Xu, Rui; Zeng, Guangming; Yang, Qi

    2017-10-15

    In this work, a low-cost alternative approach (i.e., adding aged refuse (AR) into waste activated sludge) to significantly enhance anaerobic digestion of sludge was reported. Experimental results showed that with the addition dosage of AR increasing from 0 to 400 mg/g dry sludge soluble chemical oxygen demand (COD) increased from 1150 to 5240 mg/L at the digestion time of 5 d, while the maximal production of volatile fatty acids (VFA) increased from 82.6 to 183.9 mg COD/g volatile suspended solids. Although further increase of AR addition decreased the concentrations of both soluble COD and VFA, their contents in these systems with AR addition at any concentration investigated were still higher than those in the blank, which resulted in higher methane yields in these systems. Mechanism studies revealed that pertinent addition of AR promoted solubilization, hydrolysis, and acidogenesis processes and did not affect methanogenesis significantly. It was found that varieties of enzymes and anaerobes in AR were primary reason for the enhancement of anaerobic digestion. Humic substances in AR benefited hydrolysis and acidogenesis but inhibited methanogenesis. The effect of heavy metals in AR on sludge anaerobic digestion was dosage dependent. Sludge anaerobic digestion was enhanced by appropriate amounts of heavy metals but inhibited by excessive amounts of heavy metals. The relative abundances of microorganisms responsible for sludge hydrolysis and acidogenesis were also observed to be improved in the system with AR addition, which was consistent with the performance of anaerobic digestion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. A novel paleo-bleaching proxy using boron isotopes and high-resolution laser ablation to reconstruct coral bleaching events

    Dishon, G.; Fisch, J.; Horn, Ingo; Kaczmarek, Karina; Bijma, Jelle; Gruber, D.F.; Nir, O.; Popovich, Y.; Tchernov, D.

    2015-01-01

    Coral reefs occupy only ~ 0.1 percent of the ocean's habitat, but are the most biologically diverse marine ecosystem. In recent decades, coral reefs have experienced a significant global decline due to a variety of causes, one of the major causes being widespread coral bleaching events. During bleaching, the coral expels its symbiotic algae, thereby losing its main source of nutrition generally obtained through photosynthesis. While recent coral bleaching events have been ex...

  3. Activation and characterization of waste coffee grounds as bio-sorbent

    Mariana; Marwan; Mulana, F.; Yunardi; Ismail, T. A.; Hafdiansyah, M. F.

    2018-03-01

    As the city well known for its culture of coffee drinkers, modern and traditional coffee shops are found everywhere in Banda Aceh, Indonesia. High number of coffee shops in the city generates large quantities of spent coffee grounds as waste without any effort to convert them as other valuable products. In an attempt to reduce environmental problems caused by used coffee grounds, this research was conducted to utilize waste coffee grounds as an activated carbon bio-sorbent. The specific purpose of this research is to improve the performance of coffee grounds bio-sorbent through chemical and physical activation, and to characterize the produced bio-sorbent. Following physical activation by carbonization, a chemical activation was achieved by soaking the carbonized waste coffee grounds in HCl solvent and carbonization process. The activated bio-sorbent was characterized for its morphological properties using Scanning Electron Microscopy (SEM), its functional groups by Fourier Transform Infra-Red Spectrophotometer (FTIR), and its material characteristics using X-Ray Diffraction (XRD). Characterization of the activated carbon prepared from waste coffee grounds shows that it meets standard quality requirement in accordance with Indonesian National Standard, SNI 06-3730-1995. Activation process has modified the functional groups of the waste coffee grounds. Comparing to natural waste coffee grounds, the resulted bio-sorbent demonstrated a more porous surface morphology following activation process. Consequently, such bio-sorbent is a potential source to be used as an adsorbent for various applications.

  4. Long-term α-hazard of high activity waste from nuclear fuel reprocessing

    Girardi, F.; Bertozzi, G.

    1974-01-01

    The concentration and decay of α-emitters in high activity waste arising from spent nuclear fuel reprocessing was calculated under specified reference conditions. An attempt to evaluate the long-term hazard of such waste is being made by applying the ''barrier'' approach derived from reactor safety studies. Four barriers were identified, which could be evaluated in a probabilistic way by taking into account the great uncertainties present in each of them. The barriers are: 1) quality of the segregation afforded by deep geological formations, 2) stability of conditioned waste (chemical and physical), 3) retention by immediate surrounding, 4) distribution pattern of actinides in the environment. The analysis of a fictional accident showed that the uncertainties connected with the evaluation of the barriers' value are rather large. Additional studies particularly on the stability of conditioned waste and ecological properties of the environment towards actinides, would considerably improve our knowledge of the value of the barrier system. Chemical separation of actinides from high activity waste would be an additional option of undoubted value for the disposal of high activity waste. Its value for the overall safety of the entire waste inventory depends on many factors which need better evaluation, such as safety of the disposal of the separated actinides and the amount and quality of the additional waste generated by the separation process. An analysis of various levels of possible separations suggests that a reasonable target might be: Pu, Am and Cm, decontamination factor 10 3 ; Np, coextraction with U and Pu with a 90% yield

  5. Corrosion Study of Stainless Steels in Peracetic Acid Bleach Media With and Without Chloride and Chelant

    Rohtash

    2014-12-01

    Full Text Available The paper industries are adopting non-chlorine containing chemicals e.g. peroxide, ozone, peracids etc. as alternate of chlorine based bleach chemicals e.g. chlorine and chlorine dioxide etc. with the aim of eco-friend atmospheres. Changeover to the new chemicals in the bleaching process is likely to affect the metallurgy of the existing bleach plants due to change in the corrosivity of the media. Accordingly, corrosion investigations were performed in a peracid namely peracetic acid to test the suitability of austenitic stainless steels 654SMO, 265SMO, 2205, 317L and 316L. The performance of above stainless steels was evaluated through long term immersion tests and Electrochemical polarization measurements in peracetic acid (PAA bleach media at pH value 4 maintaining concentration 0.2 % as active oxygen along with three chloride levels 0, 500 and 1000 ppm in pulp-free laboratory. To study the effect of corrosion inhibitors with extending limit of chloride in liquors, measurements were also made with two types of chelants- EDTA & MgSO4. The results showed that corrosivity of PAA reduced by addition of chelant while increased with concentration of Cl¯. The results also exhibited that EDTA is better inhibitor than MgSO4.

  6. Development of MHI's induction melting system for low level radio active solid waste treatment

    Murakami, Tadashi; Hashiba, Kenji; Fukui, Hiroshi; Sato, Akio; Minemoto, Masaki

    1999-01-01

    Mitsubishi Heavy Industries, Ltd., (MHI) has developed melting facilities that reduce radioactive waste volume. The system uses a high-frequency induction to separately melt nonmetallic waste in SUS containers and metallic waste. Use of system extends refractory life. To validate system feasibility, major components were tested with the following results: (1) Two 200-liter drum cans of molten solid waste are produced per work day, (2) Radioactivity in molten solid was homogeneous with a coefficient of variation ≤10%, clarifying residue properties, (3) The radioactive decontamination factor of off-gas facilities --DF=Activity to system/Activity at the system exit --exceeded 10 7 . We confirmed system to fill the requirements for molten solid waste and have the merit of high volume-reduction and long-life refractory. (author)

  7. Office of River Protection Advanced Low-Activity Waste Glass Research and Development Plan

    Kruger, A. A.; Peeler, D. K.; Kim, D. S.; Vienna, J. D.; Piepel, G. F.; Schweiger, M. J.

    2015-01-01

    The U.S. Department of Energy Office of River Protection (ORP) has initiated and leads an integrated Advanced Waste Glass (AWG) program to increase the loading of Hanford tank wastes in glass while meeting melter lifetime expectancies and process, regulatory, and product performance requirements. The integrated ORP program is focused on providing a technical, science-based foundation for making key decisions regarding the successful operation of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) facilities in the context of an optimized River Protection Project (RPP) flowsheet. The fundamental data stemming from this program will support development of advanced glass formulations, key product performance and process control models, and tactical processing strategies to ensure safe and successful operations for both the low-activity waste (LAW) and high-level waste vitrification facilities. These activities will be conducted with the objective of improving the overall RPP mission by enhancing flexibility and reducing cost and schedule.

  8. Office of River Protection Advanced Low-Activity Waste Glass Research and Development Plan

    Kruger, A. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Peeler, D. K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kim, D. S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Vienna, J. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Piepel, G. F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schweiger, M. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-11-23

    The U.S. Department of Energy Office of River Protection (ORP) has initiated and leads an integrated Advanced Waste Glass (AWG) program to increase the loading of Hanford tank wastes in glass while meeting melter lifetime expectancies and process, regulatory, and product performance requirements. The integrated ORP program is focused on providing a technical, science-based foundation for making key decisions regarding the successful operation of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) facilities in the context of an optimized River Protection Project (RPP) flowsheet. The fundamental data stemming from this program will support development of advanced glass formulations, key product performance and process control models, and tactical processing strategies to ensure safe and successful operations for both the low-activity waste (LAW) and high-level waste vitrification facilities. These activities will be conducted with the objective of improving the overall RPP mission by enhancing flexibility and reducing cost and schedule.

  9. Waste Composite Sensor Designed by Cellulose and Activated Carbon as Ethylene Absorber

    S. Ummartyotin

    2016-01-01

    Full Text Available Activated carbon was successfully derived from scrap tile waste from thermochemical conversion. Chemical and physical modifications were therefore employed to modify the specific surface area and porosity of activated carbon. Cellulose was successfully extracted from palm front. Designation of waste composite was prepared by cellulose and activated carbon. Less than 30 wt% of activated carbon was integrated into cellulose sheet matrix. It was important to note that there is no change in mechanical and morphological properties. Small amount of activated carbon was well dispersed. In order to investigate the feasibility of composite as active packaging, oxygen permeation rate and ethylene gas adsorption ability were preliminary investigated.

  10. Developments in the management of low and intermediate activity solid wastes at the Cadarache Centre

    Barbreau, A.; Marcaillou, J.; Mery, J.; Pinto, D.; Rancon, D.

    1975-01-01

    The Cadarache Nuclear Studies Centre is located in a thinly populated region. Covering a total area of 1600 hectares, it has been able to accommodate numerous and important research facilities. In 1970, 11 reactors or critical assemblies were in operation. More than 164000 m 2 are devoted to laboratories, testing areas, installations for the inspection of irradiated fuel elements and plutonium technology workshops. Up to 1968 the low- and intermediate-activity solid wastes (categories 1, 2 and 30) collected at the Centre were divided into two classes for disposal purposes: (a) burnable wastes which, after sorting, were destroyed in an incinerator; (b) compressible wastes which were compacted in concrete containers after recovery of the packing, by means of a 250-ton press. The situation at Cadarache and the results obtained in hydrogeological studies have prompted the Centre to improve the processing of these wastes and reduce the cost. The treatment of solid wastes should, in effect, be regarded as a step towards their final elimination. The measure envisaged at Cadarache were thus aimed at permitting final storage on site, in order to reduce the volume of waste, contain the activity and keep the cost to a minimum. The management of solid wastes is at present based on the following methods: (a) storage in trenches with PVC packing for non-burnable solid wastes of categories 1 and 4, after monitoring of specific activities; (b) compacting and storage in leak-proof pools for solid wastes of categories 2 and 3, the most highly active undergoing a period of decay storage beforehand; (c) incineration of burnable solid wastes of categories 1 and 2 and also of contaminated oils and solvents. (author)

  11. Experimental Design for Hanford Low-Activity Waste Glasses with High Waste Loading

    Piepel, Gregory F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cooley, Scott K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Vienna, John D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Crum, Jarrod V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-07-24

    This report discusses the development of an experimental design for the initial phase of the Hanford low-activity waste (LAW) enhanced glass study. This report is based on a manuscript written for an applied statistics journal. Appendices A, B, and E include additional information relevant to the LAW enhanced glass experimental design that is not included in the journal manuscript. The glass composition experimental region is defined by single-component constraints (SCCs), linear multiple-component constraints (MCCs), and a nonlinear MCC involving 15 LAW glass components. Traditional methods and software for designing constrained mixture experiments with SCCs and linear MCCs are not directly applicable because of the nonlinear MCC. A modification of existing methodology to account for the nonlinear MCC was developed and is described in this report. One of the glass components, SO3, has a solubility limit in glass that depends on the composition of the balance of the glass. A goal was to design the experiment so that SO3 would not exceed its predicted solubility limit for any of the experimental glasses. The SO3 solubility limit had previously been modeled by a partial quadratic mixture model expressed in the relative proportions of the 14 other components. The partial quadratic mixture model was used to construct a nonlinear MCC in terms of all 15 components. In addition, there were SCCs and linear MCCs. This report describes how a layered design was generated to (i) account for the SCCs, linear MCCs, and nonlinear MCC and (ii) meet the goals of the study. A layered design consists of points on an outer layer, and inner layer, and a center point. There were 18 outer-layer glasses chosen using optimal experimental design software to augment 147 existing glass compositions that were within the LAW glass composition experimental region. Then 13 inner-layer glasses were chosen with the software to augment the existing and outer

  12. Experimental Design for Hanford Low-Activity Waste Glasses with High Waste Loading

    Piepel, Gregory F.; Cooley, Scott K.; Vienna, John D.; Crum, Jarrod V.

    2015-01-01

    This report discusses the development of an experimental design for the initial phase of the Hanford low-activity waste (LAW) enhanced glass study. This report is based on a manuscript written for an applied statistics journal. Appendices A, B, and E include additional information relevant to the LAW enhanced glass experimental design that is not included in the journal manuscript. The glass composition experimental region is defined by single-component constraints (SCCs), linear multiple-component constraints (MCCs), and a nonlinear MCC involving 15 LAW glass components. Traditional methods and software for designing constrained mixture experiments with SCCs and linear MCCs are not directly applicable because of the nonlinear MCC. A modification of existing methodology to account for the nonlinear MCC was developed and is described in this report. One of the glass components, SO 3 , has a solubility limit in glass that depends on the composition of the balance of the glass. A goal was to design the experiment so that SO 3 would not exceed its predicted solubility limit for any of the experimental glasses. The SO 3 solubility limit had previously been modeled by a partial quadratic mixture model expressed in the relative proportions of the 14 other components. The partial quadratic mixture model was used to construct a nonlinear MCC in terms of all 15 components. In addition, there were SCCs and linear MCCs. This report describes how a layered design was generated to (i) account for the SCCs, linear MCCs, and nonlinear MCC and (ii) meet the goals of the study. A layered design consists of points on an outer layer, and inner layer, and a center point. There were 18 outer-layer glasses chosen using optimal experimental design software to augment 147 existing glass compositions that were within the LAW glass composition experimental region. Then 13 inner-layer glasses were chosen with the software to augment the existing and outer-layer glasses. The experimental

  13. Experiment of Industrial Waste Absorption using Activated Carbon from Coal of Tanjung Tabalong, South Kalimantan

    M. Ulum Gani

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v6i4.130Activated carbon made from Tanjung Tabalong coal was investigated its absorption capability to organic and inorganic elements in industrial waste. Coal was carbonized at low temperature of 600C to produce semicoke, and then was activated at temperature of 700C with activation time of 120 minutes with water steam flow. The absorption capability of activated carbon to chemical oxygen demand (COD was performed using 2.5 and 9.0 g activated carbon for 250 ml and 300 ml COD waste respectively. The agitation time of each experiment were 30, 60, and 90 minutes. Atomic absorption spectrophotometer (AAS was used to analyze the COD waste. The result shows that 2.5 g activated carbon could absorb COD waste ranging from 6.9-67.5 %, while the utilization of 9 g could absorb COD waste ranging from 88.9 - 100 %. The more activated carbon and the longer time of agitation used in this experiment, the more the absorption of COD waste.

  14. SELENIUM TREATMENT/REMOVAL ALTERNATIVES DEMONSTRATION PROJECT - MINE WASTE TECHNOLOGY PROGRAM ACTIVITY III, PROJECT 20

    This document is the final report for EPA's Mine WAste Technology Program (MWTP) Activity III, Project 20--Selenium Treatment/Removal Alternatives Demonstration project. Selenium contamination originates from many sources including mining operations, mineral processing, abandoned...

  15. Removing radio-active wastes from nuclear power stations by the STEAG system

    Baatz, H.

    1978-01-01

    The mobile STEAG System for conditioning radio-active wastes from nuclear power stations represents a particularly safe and economic method of removing them in present day conditions. Cementation by the FAFNIR System is used for the greater part of the waste, the liquid concentrate (evaporator concentrate and filter slurry). For the special case of the medium active resin balls from the primary circuits, embedding in plastic by the FAMA process has proved to be the only available successful process so far. The highly active solid waste from the reactor core is decomposed by the MOSAIK System, is packed in transportable and storable containers and is removed from the fuel element storage pond. The systems are so safe that faults or interruptions of power station operation due to faults in removing radio-active wastes can be excluded. (orig.) [de

  16. Laser Teeth Bleaching: Evaluation of Eventual Side Effects on Enamel and the Pulp and the Efficiency In Vitro and In Vivo

    De Moor, Roeland Jozef Gentil; Meire, Maarten August; De Coster, Peter Jozef

    2015-01-01

    Light and heat increase the reactivity of hydrogen peroxide. There is no evidence that light activation (power bleaching with high-intensity light) results in a more effective bleaching with a longer lasting effect with high concentrated hydrogen peroxide bleaching gels. Laser light differs from conventional light as it requires a laser-target interaction. The interaction takes place in the first instance in the bleaching gel. The second interaction has to be induced in the tooth, more specifically in the dentine. There is evidence that interaction exists with the bleaching gel: photothermal, photocatalytical, and photochemical interactions are described. The reactivity of the gel is increased by adding photocatalyst of photosensitizers. Direct and effective photobleaching, that is, a direct interaction with the colour molecules in the dentine, however, is only possible with the argon (488 and 415 nm) and KTP laser (532 nm). A number of risks have been described such as heat generation. Nd:YAG and especially high power diode lasers present a risk with intrapulpal temperature elevation up to 22°C. Hypersensitivity is regularly encountered, being it of temporary occurrence except for a number of diode wavelengths and the Nd:YAG. The tooth surface remains intact after laser bleaching. At present, KTP laser is the most efficient dental bleaching wavelength. PMID:25874258

  17. A new, high-resolution global mass coral bleaching database.

    Simon D Donner

    Full Text Available Episodes of mass coral bleaching have been reported in recent decades and have raised concerns about the future of coral reefs on a warming planet. Despite the efforts to enhance and coordinate coral reef monitoring within and across countries, our knowledge of the geographic extent of mass coral bleaching over the past few decades is incomplete. Existing databases, like ReefBase, are limited by the voluntary nature of contributions, geographical biases in data collection, and the variations in the spatial scale of bleaching reports. In this study, we have developed the first-ever gridded, global-scale historical coral bleaching database. First, we conducted a targeted search for bleaching reports not included in ReefBase by personally contacting scientists and divers conducting monitoring in under-reported locations and by extracting data from the literature. This search increased the number of observed bleaching reports by 79%, from 4146 to 7429. Second, we employed spatial interpolation techniques to develop annual 0.04° × 0.04° latitude-longitude global maps of the probability that bleaching occurred for 1985 through 2010. Initial results indicate that the area of coral reefs with a more likely than not (>50% or likely (>66% probability of bleaching was eight times higher in the second half of the assessed time period, after the 1997/1998 El Niño. The results also indicate that annual maximum Degree Heating Weeks, a measure of thermal stress, for coral reefs with a high probability of bleaching increased over time. The database will help the scientific community more accurately assess the change in the frequency of mass coral bleaching events, validate methods of predicting mass coral bleaching, and test whether coral reefs are adjusting to rising ocean temperatures.

  18. A new, high-resolution global mass coral bleaching database.

    Donner, Simon D; Rickbeil, Gregory J M; Heron, Scott F

    2017-01-01

    Episodes of mass coral bleaching have been reported in recent decades and have raised concerns about the future of coral reefs on a warming planet. Despite the efforts to enhance and coordinate coral reef monitoring within and across countries, our knowledge of the geographic extent of mass coral bleaching over the past few decades is incomplete. Existing databases, like ReefBase, are limited by the voluntary nature of contributions, geographical biases in data collection, and the variations in the spatial scale of bleaching reports. In this study, we have developed the first-ever gridded, global-scale historical coral bleaching database. First, we conducted a targeted search for bleaching reports not included in ReefBase by personally contacting scientists and divers conducting monitoring in under-reported locations and by extracting data from the literature. This search increased the number of observed bleaching reports by 79%, from 4146 to 7429. Second, we employed spatial interpolation techniques to develop annual 0.04° × 0.04° latitude-longitude global maps of the probability that bleaching occurred for 1985 through 2010. Initial results indicate that the area of coral reefs with a more likely than not (>50%) or likely (>66%) probability of bleaching was eight times higher in the second half of the assessed time period, after the 1997/1998 El Niño. The results also indicate that annual maximum Degree Heating Weeks, a measure of thermal stress, for coral reefs with a high probability of bleaching increased over time. The database will help the scientific community more accurately assess the change in the frequency of mass coral bleaching events, validate methods of predicting mass coral bleaching, and test whether coral reefs are adjusting to rising ocean temperatures.

  19. Recovery of cat retinal ganglion cell sensitivity following pigment bleaching.

    Bonds, A B; Enroth-Cugell, C

    1979-01-01

    1. The threshold illuminance for small spot stimulation of on-centre cat retinal ganglion cells was plotted vs. time after exposure to adapting light sufficiently strong to bleach significant amounts of rhodopsin. 2. When the entire receptive field of an X- or Y-type ganglion cell is bleached by at most 40%, recovery of the cell's rod-system proceeds in two phases: an early relatively fast one during which the response appears transient, and a late, slower one during which responses become more sustained. Log threshold during the later phase is well fit by an exponential in time (tau = 11.5-38 min). 3. After bleaches of 90% of the underlying pigment, threshold is cone-determined for as long as 40 min. Rod threshold continues to decrease for at least 85 min after the bleach. 4. The rate of recovery is slower after strong than after weak bleaches; 10 and 90% bleaches yield time constants for the later phase of 11.5 and 38 min, respectively. This contrasts with an approximate time constant of 11 min for rhodopsin regeneration following any bleach. 5. The relationship between the initial elevation of log rod threshold extrapolated from the fitted exponential curves and the initial amount of pigment bleached is monotonic, but nonlinear. 6. After a bleaching exposure, the maintained discharge is initially very regular. The firing rate first rises, then falls to the pre-bleach level, with more extended time courses of change in firing rate after stronger exposures. The discharge rate is restored before threshold has recovered fully. 7. The change in the response vs. log stimulus relationship after bleaching is described as a shift of the curve to the right, paired with a decrease in slope of the linear segment of the curve. PMID:521963

  20. Nuclear energy - Waste-packages activity measurement - Part.1: high-resolution gamma spectrometry in integral mode with open geometry

    2004-01-01

    ISO 14850:2004 describes a procedure for measurements of gamma-emitting radionuclide activity in homogeneous objects such as unconditioned waste (including process waste, dismantling waste, etc.), waste conditioned in various matrices (bitumen, hydraulic binder, thermosetting resins, etc.), notably in the form of 100 L, 200 L, 400 L or 800 L drums, and test specimens or samples, (vitrified waste), and waste packaged in a container, notably technological waste. It also specifies the calibration of the gamma spectrometry chain. The gamma energies used generally range from 0,05 MeV to 3 MeV. (authors)

  1. NDA generic research programme for higher activity waste management issues - 16390

    McKinney, James; Brownridge, Melanie

    2009-01-01

    NDA has a responsibility to ensure decommissioning activities are sufficiently technically underpinned and appropriate Research and Development (Rand D) is carried out. The NDA funds research and development (R and D) indirectly via the Site Licence Companies (SLCs) or directly. The main component of directly funded R and D is the NDA Direct Research Portfolio (DRP). The DRP is split into four framework areas: - University Interactions; - Waste Processing; - Material Characterisation; - Actinide and Strategic Nuclear Materials. These four framework areas were competed through an Official Journal of European Union (OJEU) process in 2008. Although all four areas involve waste management, Waste Processing and Material Characterisation specifically deal with Higher Activity Waste (HAW) waste management issues. The Waste Processing area was awarded to three groups: (i) National Nuclear Laboratory (NNL), (ii) Consortium led by Hyder Consulting Ltd, and (iii) Consortium led by UKAEA Ltd. The Material Characterisation area was awarded to three groups: (i) NNL, (ii) Serco, and (iii) Consortium led by UKAEA Ltd. The initial work in Waste Processing and Material Characterisation was centered on establishing a forward research programme to address the generic needs of the UK civil nuclear industry and the NDA strategic drivers for waste management and land quality. This has been achieved by the four main framework contractors from the Waste Processing and Materials Characterisation areas working together with the NDA to identify the key research themes and begin the development of the NDA's HAW Management Research Programme. The process also involves active engagement with both industry and regulators via the Nuclear Waste Research Forum (NWRF). The NDA's HAW Management Research Programme includes a number of themes: - Optimisation of Interim Store Operation and Design; - Alternative Waste Encapsulants; - Waste Package Integrity; - Alternative Waste treatment methods

  2. Low-activity waste envelope definitions for the TWRS Privatization Phase I Request For Proposal

    Patello, G.K.; Lauerhass, L.; Myers, R.L.; Wiemers, K.D.

    1996-11-01

    Radioactive waste has been stored in large underground storage tanks at the Hanford Site since 1944. Approximately 212 million liters of waste containing approximately 240,000 metric tons of processed chemicals and 177 mega-curies of radionuclides are now stored in 177 tanks. These caustic wastes are in the form of liquids, slurries, saltcakes, and sludge. In 1991, the Tank Waste Remediation System (TWRS) Program was established to manage, retrieve, treat, immobilize, and dispose of these wastes in a safe, environmentally sound, and cost-effective manner. The Department of Energy (DOE) has believes that it is feasible to privatize portions of the TWRS Program. Under the privatization strategy embodied in the Request for Proposal (RFP), DOE will purchase services from a contractor-owned, contractor-operated facility under a fixed-price contract. Phase I of the TWRS privatization strategy is a proof-of-concept/commercial demonstration-scale effort. The objectives of Phase I are to demonstrate the technical and business viability of using privatized facilities to treat Hanford tank waste; define and maintain required levels of radiological, nuclear, process, and occupational safety; maintain environmental protection and compliance; and substantially reduce life-cycle costs and time required to treat Hanford tank waste. Three low-activity waste (LAW) envelopes are identified for Phase I of the privatization contract and are representative of the range of Hanford double-shelled tank (DST) waste

  3. Low-activity waste envelope definitions for the TWRS Privatization Phase I Request For Proposal

    Patello, G.K.; Lauerhass, L.; Myers, R.L.; Wiemers, K.D.

    1996-11-01

    Radioactive waste has been stored in large underground storage tanks at the Hanford Site since 1944. Approximately 212 million liters of waste containing approximately 240,000 metric tons of processed chemicals and 177 mega-curies of radionuclides are now stored in 177 tanks. These caustic wastes are in the form of liquids, slurries, saltcakes, and sludge. In 1991, the Tank Waste Remediation System (TWRS) Program was established to manage, retrieve, treat, immobilize, and dispose of these wastes in a safe, environmentally sound, and cost-effective manner. The Department of Energy (DOE) has believes that it is feasible to privatize portions of the TWRS Program. Under the privatization strategy embodied in the Request for Proposal (RFP), DOE will purchase services from a contractor-owned, contractor-operated facility under a fixed-price contract. Phase I of the TWRS privatization strategy is a proof-of-concept/commercial demonstration-scale effort. The objectives of Phase I are to demonstrate the technical and business viability of using privatized facilities to treat Hanford tank waste; define and maintain required levels of radiological, nuclear, process, and occupational safety; maintain environmental protection and compliance; and substantially reduce life-cycle costs and time required to treat Hanford tank waste. Three low-activity waste (LAW) envelopes are identified for Phase I of the privatization contract and are representative of the range of Hanford double-shelled tank (DST) waste.

  4. Techniques for sampling nuclear waste tank contents and in situ measurement of activity

    Lawrence, R.C.

    1978-04-01

    A study was conducted to develop suitable sampling equipment and techniques for characterizing the mechanical properties of nuclear wastes; identifying effective means of measuring radiation levels, temperatures, and neutron fluxes in situ in wastes; and developing a waste core sampler. A portable, stainless steel probe was developed which is placed in the tank through a riser. This probe is built for the insertion of instrumentation that can measure the contents of the tank at any level and take temperature, radiation, and neutron activation readings with reliable accuracy. A simple and reliable instrument for the in situ extraction of waste materials ranging from liquid to concrete-like substances was also developed. This portable, stainless steel waste core sampler can remove up to one liter of radioactive waste from tanks for transportation to hot cell laboratories for analysis of hardness, chemical form, and isotopic content. A cask for transporting the waste samples from the tanks to the laboratory under radiation-protected conditions was also fabricated. This cask was designed with a ''boot'' or inner-seal liner to contain any radioactive wastes that might remain on the outside of the waste core sampling device

  5. Chromium removal from water by activated carbon developed from waste rubber tires.

    Gupta, Vinod Kumar; Ali, Imran; Saleh, Tawfik A; Siddiqui, M N; Agarwal, Shilpi

    2013-03-01

    Because of the continuous production of large amount of waste tires, the disposal of waste tires represents a major environmental issue throughout the world. This paper reports the utilization of waste tires (hard-to-dispose waste) as a precursor in the production of activated carbons (pollution-cleaning adsorbent). In the preparation of activated carbon (AC), waste rubber tire (WRT) was thermally treated and activated. The tire-derived activated carbon was characterized by means of scanning electron microscope, energy-dispersive X-ray spectroscopy, FTIR spectrophotometer, and X-ray diffraction. In the IR spectrum, a number of bands centred at about 3409, 2350, 1710, 1650, and 1300-1000 cm(-1) prove the present of hydroxyl and carboxyl groups on the surface of AC in addition to C═C double bonds. The developed AC was tested and evaluated as potential adsorbent removal of chromium (III). Experimental parameters, such as contact time, initial concentration, adsorbent dosage and pH were optimized. A rapid uptake of chromium ions was observed and the equilibrium is achieved in 1 h. It was also found that the adsorption process is pH dependent. This work adds to the global discussion of the cost-effective utilization of waste rubber tires for waste water treatment.

  6. Low-level waste research and development activities of the Department of Energy

    Barainca, M.J.

    1986-01-01

    This paper presents an overview of the technical activities of the Department of Energy's Defense and Nuclear Energy Low-Level Radioactive Waste Management Programs (LLWPs). Although each Program was established with a different purpose, the technologies developed and demonstrated by each are transferable for use in both the commercial and DOE sectors. This paper presents an overview of the technical activities being pursued through both the Defense and Nuclear Energy LLWP's. These technologies have been placed in the following categories; Criteria and Standards, Systems Analysis, Information and Technology Transfer, Waste Treatment and Wast Form, Improved Near Surface Disposal, Greater Confinement Disposal, Corrective Measures, and Monitoring

  7. Production of activated carbons from waste tyres for low temperature NOx control.

    Al-Rahbi, Amal S; Williams, Paul T

    2016-03-01

    Waste tyres were pyrolysed in a bench scale reactor and the product chars were chemically activated with alkali chemical agents, KOH, K2CO3, NaOH and Na2CO3 to produce waste tyre derived activated carbons. The activated carbon products were then examined in terms of their ability to adsorb NOx (NO) at low temperature (25°C) from a simulated industrial process flue gas. This study investigates the influence of surface area and porosity of the carbons produced with the different alkali chemical activating agents on NO capture from the simulated flue gas. The influence of varying the chemical activation conditions on the porous texture and corresponding NO removal from the flue gas was studied. The activated carbon sorbents were characterized in relation to BET surface area, micropore and mesopore volumes and chemical composition. The highest NO removal efficiency for the waste tyre derived activated carbons was ∼75% which was obtained with the adsorbent treated with KOH which correlated with both the highest BET surface area and largest micropore volume. In contrast, the waste tyre derived activated carbons prepared using K2CO3, NaOH and Na2CO3 alkali activating agents appeared to have little influence on NO removal from the flue gases. The results suggest problematic waste tyres, have the potential to be converted to activated carbons with NOx removal efficiency comparable with conventionally produced carbons. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Low-activity waste feed delivery -- Minimum duration between successive batches

    Peters, B.B.

    1998-08-25

    The purpose of this study is to develop a defensible basis for establishing what ``minimum duration`` will provide acceptable risk mitigation for low-activity waste feed delivery to the privatization vendors. The study establishes a probabilistic-based duration for staging of low-activity waste feed batches. A comparison is made of the durations with current feed delivery plans and potential privatization vendor facility throughput rates.

  9. Low-activity waste feed delivery -- Minimum duration between successive batches

    Peters, B.B.

    1998-01-01

    The purpose of this study is to develop a defensible basis for establishing what ''minimum duration'' will provide acceptable risk mitigation for low-activity waste feed delivery to the privatization vendors. The study establishes a probabilistic-based duration for staging of low-activity waste feed batches. A comparison is made of the durations with current feed delivery plans and potential privatization vendor facility throughput rates

  10. Derivation of activity limits for the disposal of radioactive waste in near surface disposal facilities

    2003-12-01

    criteria for disposal of radioactive wastes to near surface facilities. These criteria are qualitative in nature and, for example, they do not address limitations on radionuclide content of waste, waste packages or the facility as a whole. This publication is to present an approach for establishing radiological waste acceptance criteria using a safety assessment methodology and to illustrate its application in establishing limits on the total activity and the activity concentrations of radioactive waste to be disposed in near surface disposal facilities. The approach makes use of accepted methods and computational schemes currently used in assessing the safety of near surface disposal facilities both during the operational and post-closure periods. The scope of this publication covers the use of safety assessment methodology to calculate total and specific activities limits for radioactive waste in near surface disposal facilities. It is used to evaluate the potential operational and post-closure radiological impact of solid and solidified radioactive waste in near surface facilities. The radioactive waste types used to illustrate the approach range from waste containing radionuclides used for medical, industrial and research purposes to waste arising from nuclear fuel cycle activities. They also include waste arising from the decommissioning of nuclear facilities. The focus of the publication is on using of safety assessment methodology in derivation of quantitative radioactivity limits. This report deals with the role of activity limits in disposal system safety (Section 2), the relevant radiation protection criteria (Section 3), the approach to derive activity limits (Section 4), illustrations of the application of this approach (Section 5), and guidance on the use of the approach (Section 6)

  11. Low-level radioactive waste from nuclear power generating stations: Characterization, classification and assessment of activated metals and waste streams

    Thomas, V.W.; Robertson, D.E.; Thomas, C.W.

    1993-02-01

    Since the enactment of 10 CFR Part 61, additional difficult-to-measure long-lived radionuclides, not specified in Tables 1 2 of Part 61, have been identified (e.g., 108m Ag, 93 Mo, 36 Cl, 10 Be, 113m Cd, 121m Sn, 126 Sn, 93m Nb) that may be of concern in certain types of waste. These nuclides are primarily associated with activated metal and perhaps other nuclear power low-level waste (LLW) being sent to disposal facilities. The concentration of a radionuclide in waste materials is normally determined by direct measurement or by indirect calculational methods, such as using a scaling factor to relate inferred concentration of a difficult-to-measure radionuclide to another that is easily measured. The total disposal site inventory of certain difficult-to-measure radionuclides (e.g., 14 C, 129 I, and 99 Tc) often control the total quantities of radioactive waste permitted in LLW burial facilities. Overly conservative scaling factors based on lower limits of detection (LLD), often used in the nuclear power industry to estimate these controlling nuclides, could lead to premature closure of a disposal facility. Samples of LLW (Class B and C activated metals [AM] and other waste streams) are being collected from operating nuclear power stations and analyzed for radionuclides covered in 10 CFR Part 61 and the additional difficult-to-measure radionuclides. This analysis will enhance the NRC's understanding of the distribution and projected quantities of radionuclides within AM and LLW streams from commercial nuclear power stations. This research will also provide radiological characterization of AM specimens for others to use in leach-rate and lysimeter experiments to determine nuclide releases and subsequent movement in natural soil environments

  12. Co-conditioning and dewatering of chemical sludge and waste activated sludge.

    Chang, G R; Liu, J C; Lee, D J

    2001-03-01

    The conditioning and dewatering behaviors of chemical and waste activated sludges from a tannery were studied. Capillary suction time (CST), specific resistance to filtration (SRF), and bound water content were used to evaluate the sludge dewatering behaviors. Zeta potentials were also measured. Experiments were conducted on each sludge conditioned and dewatered separately, and on the sludge mixed at various ratios. Results indicate that the chemical sludge was relatively difficult to be dewatered, even in the presence of polyelectrolyte. When the waste activated sludge was mixed with the chemical sludge at ratios of 1:1 and 2:1, respectively, the dewaterability of chemical sludge improved remarkably while the relatively better dewaterability of the waste activated sludge deteriorated only to a limited extent. As the mixing ratios became 4:1 and 8:1, the dewaterability of the mixed sludge was equal to that of the waste activated sludge. The optimal polyelectrolyte dosage for the mixed sludge was equal to or less than that of the waste activated sludge. It is proposed that the chemical sludges act as skeleton builders that reduce the compressibility of the mixed sludge whose dewaterability is enhanced. Bound water contents of sludge decreased at low polyelectrolyte dosage and were not significantly affected as polyelectrolyte dosage increased. Advantages and disadvantages of co-conditioning and dewatering chemical sludge and waste activated sludge were discussed.

  13. Climate change and coral reef bleaching: An ecological assessment of long-term impacts, recovery trends and future outlook

    Baker, Andrew C.; Glynn, Peter W.; Riegl, Bernhard

    2008-12-01

    regenerating and recovering coral reefs have originated from broadcast spawning taxa with a potential for asexual growth, relatively long distance dispersal, successful settlement, rapid growth and a capacity for framework construction. Whether or not affected reefs can continue to function as before will depend on: (1) how much coral cover is lost, and which species are locally extirpated; (2) the ability of remnant and recovering coral communities to adapt or acclimatize to higher temperatures and other climatic factors such as reductions in aragonite saturation state; (3) the changing balance between reef accumulation and bioerosion; and (4) our ability to maintain ecosystem resilience by restoring healthy levels of herbivory, macroalgal cover, and coral recruitment. Bleaching disturbances are likely to become a chronic stress in many reef areas in the coming decades, and coral communities, if they cannot recover quickly enough, are likely to be reduced to their most hardy or adaptable constituents. Some degraded reefs may already be approaching this ecological asymptote, although to date there have not been any global extinctions of individual coral species as a result of bleaching events. Since human populations inhabiting tropical coastal areas derive great value from coral reefs, the degradation of these ecosystems as a result of coral bleaching and its associated impacts is of considerable societal, as well as biological concern. Coral reef conservation strategies now recognize climate change as a principal threat, and are engaged in efforts to allocate conservation activity according to geographic-, taxonomic-, and habitat-specific priorities to maximize coral reef survival. Efforts to forecast and monitor bleaching, involving both remote sensed observations and coupled ocean-atmosphere climate models, are also underway. In addition to these efforts, attempts to minimize and mitigate bleaching impacts on reefs are immediately required. If significant reductions in

  14. The Remote Handled Immobilization Low-Activity Waste Disposal Facility Environmental Permits and Approval Plan

    DEFFENBAUGH, M.L.

    2000-01-01

    The purpose of this document is to revise Document HNF-SD-ENV-EE-003, ''Permitting Plan for the Immobilized Low-Activity Waste Project, which was submitted on September 4, 1997. That plan accounted for the interim storage and disposal of Immobilized-Low Activity Waste at the existing Grout Treatment Facility Vaults (Project W-465) and within a newly constructed facility (Project W-520). Project W-520 was to have contained a combination of concrete vaults and trenches. This document supersedes that plan because of two subsequent items: (1) A disposal authorization that was received on October 25, 1999, in a U. S. Department of Energy-Headquarters, memorandum, ''Disposal Authorization Statement for the Department of Energy Hanford site Low-Level Waste Disposal facilities'' and (2) ''Breakthrough Initiative Immobilized Low-Activity Waste (ILAW) Disposal Alternative,'' August 1999, from Lucas Incorporated, Richland, Washington. The direction within the U. S. Department of Energy-Headquarters memorandum was given as follows: ''The DOE Radioactive Waste Management Order requires that a Disposal authorization statement be obtained prior to construction of new low-level waste disposal facility. Field elements with the existing low-level waste disposal facilities shall obtain a disposal authorization statement in accordance with the schedule in the complex-wide Low-Level Waste Management Program Plan. The disposal authorization statement shall be issued based on a review of the facility's performance assessment and composite analysis or appropriate CERCLA documentation. The disposal authorization shall specify the limits and conditions on construction, design, operations, and closure of the low-level waste facility based on these reviews. A disposal authorization statement is a part of the required radioactive waste management basis for a disposal facility. Failure to obtain a disposal authorization statement or record of decision shall result in shutdown of an operational

  15. Radioactive waste package assay facility. Volume 2. Investigation of active neutron and active gamma interrogation

    Bailey, M.; Bunce, L.J.; Findlay, D.J.S.; Jolly, J.E.; Parsons, T.V.; Sene, M.R.; Swinhoe, M.T.

    1992-01-01

    Volume 2 of this report describes the theoretical and experimental work carried out at Harwell on active neutron and active gamma interrogation of 500 litre cemented intermediate level waste drums. The design of a suitable neutron generating target in conjunction with a LINAC was established. Following theoretical predictions of likely neutron responses, an experimental assay assembly was built. Responses were measured for simulated drums of ILW, based on CAGR, Magnox and PCM wastes. Good correlations were established between quantities of 235 -U, nat -U and D 2 O contained in the drums, and the neutron signals. Expected sensitivities are -1g of fissile actinide and -100g of total actinide. A measure of spatial distribution is obtainable. The neutron time spectra obtained during neutron interrogation were more complex than expected, and more analysis is needed. Another area of discrepancy is the difference between predicted and measured thermal neutron flux in the drum. Clusters of small 3 He proportional counters were found to be much superior for fast neutron detection than larger diameter counters. It is necessary to ensure constancy of electron beam position relative to target(s) and drum, and prudent to measure the target neutron or gamma output as appropriate. 59 refs., 77 figs., 11 tabs

  16. Waste management, waste resource facilities and waste conversion processes

    Demirbas, Ayhan

    2011-01-01

    In this study, waste management concept, waste management system, biomass and bio-waste resources, waste classification, and waste management methods have been reviewed. Waste management is the collection, transport, processing, recycling or disposal, and monitoring of waste materials. A typical waste management system comprises collection, transportation, pre-treatment, processing, and final abatement of residues. The waste management system consists of the whole set of activities related to handling, treating, disposing or recycling the waste materials. General classification of wastes is difficult. Some of the most common sources of wastes are as follows: domestic wastes, commercial wastes, ashes, animal wastes, biomedical wastes, construction wastes, industrial solid wastes, sewer, biodegradable wastes, non-biodegradable wastes, and hazardous wastes.

  17. Data Packages for the Hanford Immobilized Low Activity Tank Waste Performance Assessment 2001 Version [SEC 1 THRU 5

    MANN, F.M.

    2000-03-02

    Data package supporting the 2001 Immobilized Low-Activity Waste Performance Analysis. Geology, hydrology, geochemistry, facility, waste form, and dosimetry data based on recent investigation are provided. Verification and benchmarking packages for selected software codes are provided.

  18. Physiological and biogeochemical traits of bleaching and recovery in the mounding species of coral Porites lobata: implications for resilience in mounding corals.

    Stephen J Levas

    Full Text Available Mounding corals survive bleaching events in greater numbers than branching corals. However, no study to date has determined the underlying physiological and biogeochemical trait(s that are responsible for mounding coral holobiont resilience to bleaching. Furthermore, the potential of dissolved organic carbon (DOC as a source of fixed carbon to bleached corals has never been determined. Here, Porites lobata corals were experimentally bleached for 23 days and then allowed to recover for 0, 1, 5, and 11 months. At each recovery interval a suite of analyses were performed to assess their recovery (photosynthesis, respiration, chlorophyll a, energy reserves, tissue biomass, calcification, δ(13C of the skeletal, δ(13C, and δ(15N of the animal host and endosymbiont fractions. Furthermore, at 0 months of recovery, the assimilation of photosynthetically acquired and zooplankton-feeding acquired carbon into the animal host, endosymbiont, skeleton, and coral-mediated DOC were measured via (13C-pulse-chase labeling. During the first month of recovery, energy reserves and tissue biomass in bleached corals were maintained despite reductions in chlorophyll a, photosynthesis, and the assimilation of photosynthetically fixed carbon. At the same time, P. lobata corals catabolized carbon acquired from zooplankton and seemed to take up DOC as a source of fixed carbon. All variables that were negatively affected by bleaching recovered within 5 to 11 months. Thus, bleaching resilience in the mounding coral P. lobata is driven by its ability to actively catabolize zooplankton-acquired carbon and seemingly utilize DOC as a significant fixed carbon source, facilitating the maintenance of energy reserves and tissue biomass. With the frequency and intensity of bleaching events expected to increase over the next century, coral diversity on future reefs may favor not only mounding morphologies but species like P. lobata, which have the ability to utilize heterotrophic

  19. The effects of habitat on coral bleaching responses in Kenya.

    Grimsditch, Gabriel; Mwaura, Jelvas M; Kilonzo, Joseph; Amiyo, Nassir

    2010-06-01

    This study examines the bleaching responses of scleractinian corals at four sites in Kenya (Kanamai, Vipingo, Mombasa and Nyali) representing two distinct lagoon habitats (relatively shallow and relatively deep). Bleaching incidence was monitored for the whole coral community, while zooxanthellae densities and chlorophyll levels were monitored for target species (Pocillopora damicornis, Porites lutea, and Porites cylindrica) during a non-bleaching year (2006) and a year of mild-bleaching (2007). Differences in bleaching responses between habitats were observed, with shallower sites Kanamai and Vipingo exhibiting lower bleaching incidence than deeper sites Nyali and Mombasa. These shallower lagoons display more fluctuating thermal and light environments than the deeper sites, suggesting that corals in the shallower lagoons have acclimatized and/or adapted to the fluctuating environmental conditions they endure on a daily basis and have become more resistant to bleaching stress. In deeper sites that did exhibit higher bleaching (Mombasa and Nyali), it was found that coral recovery occurred more quickly in the protected area than in the non-protected area.

  20. Investigating Motivations for Women's Skin Bleaching in Tanzania

    Lewis, Kelly M.; Robkin, Navit; Gaska, Karie; Njoki, Lillian Carol

    2011-01-01

    Why do many African women continue to use damaging skin-bleaching cosmetics that contain dangerous chemicals (e.g., mercury) that may increase their rates of infertility, skin cancer, and serious skin/brain/kidney disease? To address this question, our study investigated motivations driving the preservation of skin-bleaching practices in Tanzania.…

  1. The evaluation of hydrogen peroxide bleaching of Gonometa ...

    The effect of hydrogen peroxide bleaching on Gonometa postica silk and the influence that temperature, pH and time duration had on hydrogen peroxide release , colour change, breaking load and stiffness were determined. The best bleaching (81 delta E) of the Gonometa postica silk fabric was obtained with 60 minutes ...

  2. The Bleaching Syndrome: The Role of Educational Intervention

    Hall, Ronald E.

    2016-01-01

    Per the Bleaching Syndrome, people of color, including African, Asian, and Latino Americans, are both victims and perpetrators of color discrimination. The Bleaching Syndrome encompasses perceptual, psychological, and behavioral sectors that affect students' schooling experiences. Education professionals, including teachers, administrators, and…

  3. Effects of a New Bleaching Gel on Tooth Whitening

    2016-05-17

    that claims "wow’’ results and permanent whiteness unaffected by consumption of coffee, tea, or red wine with low to no sensitivity. KOR has also...bleaching to result in greater lightness {delta L *)than Home bleaching, suggesting no overall benefit from either technique. Two recent clinical

  4. Effect of a New Bleaching Gel on Tooth Whitening

    2016-05-12

    that claims “wow” results and permanent whiteness unaffected by consumption of coffee, tea, or red wine with low to no sensitivity. KöR has also...tendency for Combined bleaching to result in greater lightness (delta L*) than Home bleaching, suggesting no overall benefit from either technique

  5. The bleaching syndrome: manifestation of a post-colonial pathology ...

    The post-colonial root of African problems is directly related to skin color. Under the cloak of personal preference, light skin among African women has replaced dark skin as the native ideal. The aftermath is manifestation of the Bleaching Syndrome. Social Work professionals have overlooked the Bleaching Syndrome as ...

  6. Does deposition depth control the OSL bleaching of fluvial sediment?

    Cunningham, A. C.; Wallinga, J.; Hobo, N.; Versendaal, A. J.; Makaske, B.; Middelkoop, H.

    2014-01-01

    The Optically Stimulated Luminescence (OSL) signal from fluvial sediment often contains a remnant from the previous deposition cycle, leading to a partially bleached equivalent-dose distribution. Although identification of the burial dose is of primary concern, the degree of bleaching could

  7. Waste minimization activities in the Materials Fabrication Division at Lawrence Livermore National Laboratory

    Dini, J.W.

    1991-08-01

    The mission of the Materials Fabrication Division (MFD) is to provide fabrication services and technology in support of all programs at Lawrence Livermore National Laboratory (LLNL). MFD involvement is called for when fabrication activity requires levels of expertise, technology, equipment, process development, hazardous processes, security, or scheduling that is typically not commercially available. Customers are encouraged to utilize private industry for fabrication activity requiring routine processing or for production applications. Our waste minimization (WM) program has been directed at source reduction and recycling in concert with the working definition of waste minimization used by EPA. The principal focus of WM activities has been on hazardous wastes as defined by RCRA, however, all pollutant emissions into air, water and land are being considered as part of the program. The incentives include: (1) economics, (2) regulatory conformance, (3) public image and (4) environmental concern. This report discusses the waste minimization program at LLNL

  8. SWEPP PAN assay system uncertainty analysis: Active mode measurements of solidified aqueous sludge waste

    Blackwood, L.G.; Harker, Y.D.; Meachum, T.R.

    1997-12-01

    The Idaho National Engineering and Environmental Laboratory is being used as a temporary storage facility for transuranic waste generated by the US Nuclear Weapons program at the Rocky Flats Plant (RFP) in Golden, Colorado. Currently, there is a large effort in progress to prepare to ship this waste to the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico. In order to meet the TRU Waste Characterization Quality Assurance Program Plan nondestructive assay compliance requirements and quality assurance objectives, it is necessary to determine the total uncertainty of the radioassay results produced by the Stored Waste Examination Pilot Plant (SWEPP) Passive Active Neutron (PAN) radioassay system. This paper is one of a series of reports quantifying the results of the uncertainty analysis of the PAN system measurements for specific waste types and measurement modes. In particular this report covers active mode measurements of weapons grade plutonium-contaminated aqueous sludge waste contained in 208 liter drums (item description codes 1, 2, 7, 800, 803, and 807). Results of the uncertainty analysis for PAN active mode measurements of aqueous sludge indicate that a bias correction multiplier of 1.55 should be applied to the PAN aqueous sludge measurements. With the bias correction, the uncertainty bounds on the expected bias are 0 ± 27%. These bounds meet the Quality Assurance Program Plan requirements for radioassay systems

  9. Recent IAEA activities to support utilisation of cementitious materials in radioactive waste management

    Ojowan, M.I.; Samanta, S.K.

    2015-01-01

    The International Atomic Energy Agency promotes a safe and effective management of radioactive waste and has suitable programmes in place to serve the needs of Member States in this area. In support of these programmes the Waste Technology Section fosters technology transfer, promotes information exchange and cooperative research, as well as builds capacity in Member States to manage radioactive wastes, resulting both from the nuclear fuel cycle and nuclear applications. Technical assistance in pre disposal area covers all of these activities and is delivered through established Agency mechanisms including publication of technical documents. While the Agency does not conduct any in-house research activities, its Coordinated Research Projects (CRPs) foster research in Member States. There are 2 CRPs concerning cementitious materials: a CRP on cements and an on-going CRP on irradiated graphite waste. The CRP on cements has resulted in the recent IAEA publication TECDOC-1701. An important activity concerned with characterisation of cementitious waste forms is the LABONET network of laboratory-based centres of expertise involved in the characterization of low and intermediate level radioactive wastes. The Waste Technology Section is preparing a series of comprehensive state of the art technical handbooks

  10. Optimisation of the Management of Higher Activity Waste in the UK - 13537

    Walsh, Ciara; Buckley, Matthew [Nuclear Decommissioning Authority, Building 587, Curie Avenue, Harwell Oxford, Didcot, Oxfordshire, OX11 0RH (United Kingdom)

    2013-07-01

    The Upstream Optioneering project was created in the Nuclear Decommissioning Authority (UK) to support the development and implementation of significant opportunities to optimise activities across all the phases of the Higher Activity Waste management life cycle (i.e. retrieval, characterisation, conditioning, packaging, storage, transport and disposal). The objective of the Upstream Optioneering project is to work in conjunction with other functions within NDA and the waste producers to identify and deliver solutions to optimise the management of higher activity waste. Historically, optimisation may have occurred on aspects of the waste life cycle (considered here to include retrieval, conditioning, treatment, packaging, interim storage, transport to final end state, which may be geological disposal). By considering the waste life cycle as a whole, critical analysis of assumed constraints may lead to cost savings for the UK Tax Payer. For example, it may be possible to challenge the requirements for packaging wastes for disposal to deliver an optimised waste life cycle. It is likely that the challenges faced in the UK are shared in other countries. It is therefore likely that the opportunities identified may also apply elsewhere, with the potential for sharing information to enable value to be shared. (authors)

  11. Status of activities: Low-level radioactive waste management in the United States

    Ozaki, C.B.; Shilkett, R.C.; Kirkpatrick, T.D.

    1989-01-01

    A primary objective of low-level radioactive waste management in the United States is to protect the health and safety of the public and the quality of the environment. In support of this objective is the development of waste treatment and disposal technologies designed to provide stabilization and long-term institutional control of low-level radioactive wastes. Presented herein is a technical review of specific low-level radioactive waste management activities in the United States. Waste treatment and disposal technologies are discussed along with the performance objectives of the technologies aimed at protecting the health and safety of the public and the quality of the environment. 13 refs., 4 figs

  12. Study of scenarios of long term management of low-activity long-life wastes

    2012-01-01

    This document reports the study of scenarios for the management of different low-activity long-life radioactive wastes with reference to different French legal texts. After a presentation of the legal and technical context, the report presents different existing and projected storages (description and safety principles for the Cires and Aube centres and for the Cigeo project of deep geological storage centre). It addresses the various aspects of radiferous and graphite waste management on a long term: inventory, parcel, waste peculiarities, management scenarios, assessment of storage in SCR. It also addresses the case of other wastes such as bituminous coated wastes, those presenting a reinforced natural radioactivity or residues of uranium conversion processing. The last part presents the main orientations for the project

  13. LLNL/YMP Waste Container Fabrication and Closure Project; GFY technical activity summary

    NONE

    1990-10-01

    The Department of Energy`s Office of Civilian Radioactive Waste Management (OCRWM) Program is studying Yucca Mountain, Nevada as a suitable site for the first US high-level nuclear waste repository. Lawrence Livermore National Laboratory (LLNL) has the responsibility for designing and developing the waste package for the permanent storage of high-level nuclear waste. This report is a summary of the technical activities for the LLNL/YMP Nuclear Waste Disposal Container Fabrication and Closure Development Project. Candidate welding closure processes were identified in the Phase 1 report. This report discusses Phase 2. Phase 2 of this effort involved laboratory studies to determine the optimum fabrication and closure processes. Because of budget limitations, LLNL narrowed the materials for evaluation in Phase 2 from the original six to four: Alloy 825, CDA 715, CDA 102 (or CDA 122) and CDA 952. Phase 2 studies focused on evaluation of candidate material in conjunction with fabrication and closure processes.

  14. Method to determine the activity concentration and total activity of radioactive waste; Metodo para determinar la concentracion de actividad y actividad total de desechos radiactivos

    Angeles C, A

    2001-02-15

    A characteristic system of radioactive waste is described to determine the concentration of radionuclides activity and the total activity of bundles of radioactive waste. The system this integrated by three subsystems: - Elevator of drums. - Electromechanics. - Gamma spectroscopy. In the system it is analyzed waste of issuing gamma specifically, and this designed for materials of relative low density and it analyzes materials of cylindrical recipients.

  15. Coral bleaching pathways under the control of regional temperature variability

    Langlais, C. E.; Lenton, A.; Heron, S. F.; Evenhuis, C.; Sen Gupta, A.; Brown, J. N.; Kuchinke, M.

    2017-11-01

    Increasing sea surface temperatures (SSTs) are predicted to adversely impact coral populations worldwide through increasing thermal bleaching events. Future bleaching is unlikely to be spatially uniform. Therefore, understanding what determines regional differences will be critical for adaptation management. Here, using a cumulative heat stress metric, we show that characteristics of regional SST determine the future bleaching risk patterns. Incorporating observed information on SST variability, in assessing future bleaching risk, provides novel options for management strategies. As a consequence, the known biases in climate model variability and the uncertainties in regional warming rate across climate models are less detrimental than previously thought. We also show that the thresholds used to indicate reef viability can strongly influence a decision on what constitutes a potential refugia. Observing and understanding the drivers of regional variability, and the viability limits of coral reefs, is therefore critical for making meaningful projections of coral bleaching risk.

  16. PPARβ/δ regulates glucocorticoid- and sepsis-induced FOXO1 activation and muscle wasting.

    Estibaliz Castillero

    Full Text Available FOXO1 is involved in glucocorticoid- and sepsis-induced muscle wasting, in part reflecting regulation of atrogin-1 and MuRF1. Mechanisms influencing FOXO1 expression in muscle wasting are poorly understood. We hypothesized that the transcription factor peroxisome proliferator-activated receptor β/δ (PPARβ/δ upregulates muscle FOXO1 expression and activity with a downstream upregulation of atrogin-1 and MuRF1 expression during sepsis and glucocorticoid treatment and that inhibition of PPARβ/δ activity can prevent muscle wasting. We found that activation of PPARβ/δ in cultured myotubes increased FOXO1 activity, atrogin-1 and MuRF1 expression, protein degradation and myotube atrophy. Treatment of myotubes with dexamethasone increased PPARβ/δ expression and activity. Dexamethasone-induced FOXO1 activation and atrogin-1 and MuRF1 expression, protein degradation, and myotube atrophy were inhibited by PPARβ/δ blocker or siRNA. Importantly, muscle wasting induced in rats by dexamethasone or sepsis was prevented by treatment with a PPARβ/δ inhibitor. The present results suggest that PPARβ/δ regulates FOXO1 activation in glucocorticoid- and sepsis-induced muscle wasting and that treatment with a PPARβ/δ inhibitor may ameliorate loss of muscle mass in these conditions.

  17. Scaling factors for the activity determination of radioactive waste from nuclear power reactors

    Medici, Marcela A.; Piumetti, Elsa H.

    2007-01-01

    Specific information of the total activity and activity concentration of the radionuclides contained is required for conditioning, transporting and final disposal of radioactive waste. Due to the complexity associated to alpha and beta measurements for these emitters it is worldwide used, particularly in the case of heterogeneous radioactive waste, the Scaling Factor Method. As in other cases, inputs of the results of the analysis of waste samples taking from waste streams are necessary. The Scaling Factor Method is based on the determination of averaged correlations between the activity concentrations of Difficult to Measure (DTM) nuclides (i.e. alpha and beta emitters) and the activity concentration of easy to measure nuclides (i.e. strong gamma emitters) called Key Nuclides (KN). In the application of this method two phases may be identified: in the first one the degree of correlation between averaged activities of DTM and a given KN is verified, and specific Scaling Factors are derived for every DTM radionuclide. In the second stage the total activity and the activity concentration of the selected KN is determined in each waste item and, by applying the SFs obtained previously, the activities of DTM nuclides are calculated. It is concluded that this method is appropriate and cost-effective and it is stressed that it is only applicable while the Nuclear Power Reactor is in operation. (author)

  18. Susceptibility of Enamel Treated with Bleaching Agents to Mineral Loss after Cariogenic Challenge

    Hüseyin Tezel

    2011-01-01

    Full Text Available Objectives. Controversial reports exist whether bleaching agents cause a susceptibility to demineralization. The aim of this study was to compare the calcium loss of enamel treated with different bleaching agents and activation methods. Method and Materials. The specimens obtained from human premolars were treated in accordance with manufacturer protocols; 10% carbamide peroxide, 38% hydrogen peroxide light-activated, 38% hydrogen peroxide laser-activated, and no treatment (control. After cariogenic challenge calcium concentrations were determined by Inductively Coupled Plasma Mass Spectrometry. Results. No differences were found between the calcium loss of the laser-activated group and 10% carbamide peroxide group (>0.05. However, the differences between laser-activated and control groups were statistically significant (0.05. On the other hand, the light-activated group showed a significantly higher calcium loss compared with the other groups (<0.05. Conclusions. The results show that bleaching agents may cause calcium loss but it seems to be a negligible quantity for clinical aspects.

  19. WATER ACTIVITY DATA ASSESSMENT TO BE USED IN HANFORD WASTE SOLUBILITY CALCULATIONS

    DISSELKAMP RS

    2011-01-06

    The purpose of this report is to present and assess water activity versus ionic strength for six solutes:sodium nitrate, sodium nitrite, sodium chloride, sodium carbonate, sodium sulfate, and potassium nitrate. Water activity is given versus molality (e.g., ionic strength) and temperature. Water activity is used to estimate Hanford crystal hydrate solubility present in the waste.

  20. Unravelling the protein preference of aquatic worms during waste activated sludge degradation

    de Valk, S.L.; Khadem, A.F.; van Lier, J.B.; de Kreuk, M.K.

    2017-01-01

    Worm predation (WP) by Tubifex tubifex was investigated using waste activated sludge (WAS) as the substrate. In order to better understand the sludge degradation mechanisms during WP, the activity of five common hydrolytic enzymes was determined and compared among the initial feed activated

  1. WATER ACTIVITY DATA ASSESSMENT TO BE USED IN HANFORD WASTE SOLUBILITY CALCULATIONS

    Disselkamp, R.S.

    2011-01-01

    The purpose of this report is to present and assess water activity versus ionic strength for six solutes:sodium nitrate, sodium nitrite, sodium chloride, sodium carbonate, sodium sulfate, and potassium nitrate. Water activity is given versus molality (e.g., ionic strength) and temperature. Water activity is used to estimate Hanford crystal hydrate solubility present in the waste.

  2. Biodiesel production from residual oils recovered from spent bleaching earth

    Huang, Yi-Pin; Chang, James I.

    2010-01-01

    This work was to study technical and economic feasibilities of converting residual oils recovered from spent bleaching earth generated at soybean oil refineries into useable biodiesel. Experimental results showed that fatty acids in the SBE residual oil were hexadecenoic acid (58.19%), stearic acid (21.49%) and oleic acid (20.32%), which were similar to those of vegetable oils. The methyl ester conversion via a transesterification process gave a yield between 85 and 90%. The biodiesel qualities were in reasonable agreement with both EN 14214 and ASTM D6751 standards. A preliminary financial analysis showed that the production cost of biodiesel from SBE oils was significantly lower than the pre-tax price of fossil diesel or those made of vegetable oils or waste cooking oils. The effects of the crude oil price and the investment on the production cost and the investment return period were also conducted. The result showed that the investment would return faster at higher crude oil price. (author)

  3. Reuse of spent bleaching earth by polymerisation of residual organics.

    Beshara, Abdelhamid; Cheeseman, Christopher R

    2014-10-01

    Spent bleaching earth (SBE) is a waste generated by the edible oil industry that currently has limited options for beneficial reuse. In excess of ∼2 million tonnes per year of SBE is generated world-wide with major quantities available in the middle-east where significant volumes of edible oils are produced. Low pressure compaction followed by heat treatment at 150°C causes polymerisation of the residual organic components in SBE and this produces monolithic samples with high unconfined compressive strengths (54MPa). SBE can therefore be used to manufacture novel clay blocks for use in construction that are bonded by polymerised vegetable oil. This represents a new, innovative and resource efficient application for SBE. In this research, commercial SBE has been characterised and the effects of key processing variables (temperature and compaction pressure) on the compressive strength, porosity and density of the SBE clay blocks are reported and the mechanisms responsible for strength development are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Bleaching of reef coelenterates in the San Blas Islands, Panama

    Lasker, Howard R.; Peters, Esther C.; Coffroth, Mary Alice

    1984-12-01

    Starting in June 1983, 25 species of hermatypic corals, gorgonians, hydrocorals, anemones and zoanthids in the San Blas Islands, Panama, began showing signs of a loss of colour leading in some cases to a white “bleached” appearance. Histologic examination of six coral species indicated that bleaching was associated with drastic reductions in the density of zooxanthellae and with the atrophy and necrosis of the animal tissue. The severity of the bleaching varied among species and many species were unaffected. The species most extensively affected were: Agaricia spp., which became completely bleached and frequently died; Montastraea annularis which bleached and continued to survive; and Millepora spp. which bleached white but quickly regained their colouration. Shallow reefs dominated by Agaricia spp. suffered the most extensive bleaching. At one site, Pico Feo, 99% of the Agaricia (32% of the living cover) was bleached. On fore reers, which were dominated by Agaricia spp. and M. annularis, the proportion of M. annularis bleached ranged from 18 to 100% and that of Agaricia spp. from 30 to 53%. Transects at Sail Rock and House Reef were surveyed in August 1983 and January 1984. At those sites, 53% of the Agaricia cover died between August and January. The remaining living cover of Agaricia and of all other species exhibited normal colouration in January. Salinity and temperature were monitored every second day at 4 m depth between May 10 and August 28, 1983 at one of the localities. Bleaching was first observed within two weeks of a 2 °C rise in temperature which occurred in late May 1983. Temperatures remained at or above 31.5 °C for the following 3 weeks and were at or above 30 °C for an additional 4 weeks. The bleaching of corals in the San Blas was most likely due to those elevanted temperatures.

  5. ALKALI-ACTIVATED CEMENT MORTARS CONTAINING RECYCLED CLAY-BASED CONSTRUCTION AND DEMOLITION WASTE

    F. Puertas

    2015-09-01

    Full Text Available The use of clay-based waste as an aggregate for concrete production is an amply studied procedure. Nonetheless, research on the use of this recycled aggregate to prepare alkaline cement mortars and concretes has yet to be forthcoming. The present study aimed to determine: the behaviour of this waste as a pozzolan in OPC systems, the mechanical strength in OPC, alkali-activated slag (AAS and fly ash (AAFA mortars and the effect of partial replacement of the slag and ash themselves with ground fractions of the waste. The pozzolanic behaviour of clay-based waste was confirmed. Replacing up to 20 % of siliceous aggregate with waste aggregate in OPC mortars induced a decline in 7 day strength (around 23 wt. %. The behaviour of waste aggregate in AAMs mortars, in turn, was observed to depend on the nature of the aluminosilicate and the replacement ratio used. When 20 % of siliceous aggregate was replaced by waste aggregate in AAS mortars, the 7 day strength values remained the same (40 MPa. In AAFA mortars, waste was found to effectively replace both the fly ash and the aggregate. The highest strength for AAFA mortars was observed when they were prepared with both a 50 % replacement ratio for the ash and a 20 % ratio for the aggregate.

  6. Performance of cement solidification with barium for high activity liquid waste including sulphate

    Waki, Toshikazu; Yamada, Motoyuki; Horikawa, Yoshihiko; Kaneko, Masaaki; Saso, Michitaka; Haruguchi, Yoshiko; Yamashita, Yu; Sakai, Hitoshi

    2009-01-01

    The target liquid waste to be solidified is generated from PWR primary loop spent resin treatment with sulphate acid, so, its main constituent is sodium sulphate and the activity of this liquid is relatively high. Waste form of this liquid waste is considered to be a candidate for the subsurface disposal. The disposed waste including sulphate is anticipated to rise a concentration of sulphate ion in the ground water around the disposal facility and it may cause degradation of materials such as cement and bentonite layer and comprise the disposal facility. There could be two approaches to avoid this problem, the strong design of the disposal facility and the minimization of sulphaste ion migration from the solidified waste. In this study, the latter approach was examined. In order to keep the low concentration of sulphate ion in the ground water, it is effective to make barium sulphate by adding barium compound into the liquid waste in solidification. However, adding equivalent amount of barium compound with sulphate ion causes difficulty of mixing, because production of barium sulphate causes high viscosity. In this study, mixing condition after and before adding cement into the liquid waste was estimated. The mixing condition was set with consideration to keep anion concentration low in the ground water and of mixing easily enough in practical operation. Long term leaching behavior of the simulated solidified waste was also analyzed by PHREEQC. And the concentration of the constitution affected to the disposal facility was estimated be low enough in the ground water. (author)

  7. Protocol for the quantification of greenhouse gas emissions from waste management activities

    2013-10-01

    ' document. The quantification of GHG emissions from waste management activities is a complex exercise. This Protocol is a living document which is going to evolve together with the improvement of calculation and measurement techniques. This Protocol is a tool for quantifying and reporting a greenhouse gas inventory from waste activities over a given time frame, typically a year. In this regard, the landfill methane emissions reported are only those estimated to be emitted in the given reporting year. The reported value does not include the future emissions resulting from the degradation of waste landfilled in and prior to the reporting year. Therefore, the reported landfill methane values based on this Protocol should not be used in the context of a comparison of greenhouse gas footprint of various waste technologies

  8. ANDRA - National Radioactive Waste Management Agency. Activity report and sustainable development 2013. Financial report 2013

    2014-01-01

    Created in 1979 within the CEA, the National Radioactive Waste Management Agency (ANDRA) was established by the December 1991 Waste Act as a public body in charge of the long-term management of all radioactive waste, under the supervision of the Ministry of Ecology, Energy, Sustainable Development and the Sea (formerly the Ministry of Industry and the Ministry of Environment), and the Ministry of Research. Its 3 basic missions were extended and their funding secured through the 2006 Planning Act: - a R and D mission to propose safe long-term solution for radioactive waste without current disposal system; this mission includes long-term storage, since the 2006 Planning Act, in order to propose interim solutions while final ones are being studied; - an industrial mission concerning, on one hand, waste acceptance criteria and control and, on the other hand, siting, construction, operation, closure and monitoring of repositories. This mission includes as well a public service mission in terms of i) collection of waste of the 'small-scale nuclear activities' producers or owners (including the so-called 'household' radioactive waste, i.e. waste owned by private individuals) and ii) clean-up and rehabilitation of orphan polluted sites; - an information mission, notably through the regular publication of the National Inventory of radioactive materials and waste. This mission includes as well an active policy of dialogue with stakeholders both at national and local level. This document is the activity and Sustainable Development Report, with the financial report, of the Andra for the year 2013

  9. ANDRA - National Radioactive Waste Management Agency. Activity report 2016. Financial report 2016

    2017-01-01

    Created in 1979 within the CEA, the National Radioactive Waste Management Agency (ANDRA) was established by the December 1991 Waste Act as a public body in charge of the long-term management of all radioactive waste, under the supervision of the Ministry of Ecology, Energy, Sustainable Development and the Sea (formerly the Ministry of Industry and the Ministry of Environment), and the Ministry of Research. Its 3 basic missions were extended and their funding secured through the 2006 Planning Act: - a R and D mission to propose safe long-term solution for radioactive waste without current disposal system; this mission includes long-term storage, since the 2006 Planning Act, in order to propose interim solutions while final ones are being studied; - an industrial mission concerning, on one hand, waste acceptance criteria and control and, on the other hand, siting, construction, operation, closure and monitoring of repositories. This mission includes as well a public service mission in terms of i) collection of waste of the 'small-scale nuclear activities' producers or owners (including the so-called 'household' radioactive waste, i.e. waste owned by private individuals) and ii) clean-up and rehabilitation of orphan polluted sites; - an information mission, notably through the regular publication of the National Inventory of radioactive materials and waste. This mission includes as well an active policy of dialogue with stakeholders both at national and local level. This document is the activity and financial report of the Andra for the year 2016

  10. ANDRA - National Radioactive Waste Management Agency. Activity report 2006. Management report - Financial statements 2006

    2007-06-01

    Created in 1979 within the CEA, the National Radioactive Waste Management Agency (ANDRA) was established by the December 1991 Waste Act as a public body in charge of the long-term management of all radioactive waste, under the supervision of the Ministry of Ecology, Energy, Sustainable Development and the Sea (formerly the Ministry of Industry and the Ministry of Environment), and the Ministry of Research. Its 3 basic missions were extended and their funding secured through the 2006 Planning Act: - a R and D mission to propose safe long-term solution for radioactive waste without current disposal system; this mission includes long-term storage, since the 2006 Planning Act, in order to propose interim solutions while final ones are being studied; - an industrial mission concerning, on one hand, waste acceptance criteria and control and, on the other hand, siting, construction, operation, closure and monitoring of repositories. This mission includes as well a public service mission in terms of i) collection of waste of the 'small-scale nuclear activities' producers or owners (including the so-called 'household' radioactive waste, i.e. waste owned by private individuals) and ii) clean-up and rehabilitation of orphan polluted sites; - an information mission, notably through the regular publication of the National Inventory of radioactive materials and waste. This mission includes as well an active policy of dialogue with stakeholders both at national and local level. This document is the activity report with the management and financial statements report of the Andra for the year 2006

  11. ANDRA - National Radioactive Waste Management Agency. Activity report 2015. Financial report 2015

    2016-01-01

    Created in 1979 within the CEA, the National Radioactive Waste Management Agency (ANDRA) was established by the December 1991 Waste Act as a public body in charge of the long-term management of all radioactive waste, under the supervision of the Ministry of Ecology, Energy, Sustainable Development and the Sea (formerly the Ministry of Industry and the Ministry of Environment), and the Ministry of Research. Its 3 basic missions were extended and their funding secured through the 2006 Planning Act: - a R and D mission to propose safe long-term solution for radioactive waste without current disposal system; this mission includes long-term storage, since the 2006 Planning Act, in order to propose interim solutions while final ones are being studied; - an industrial mission concerning, on one hand, waste acceptance criteria and control and, on the other hand, siting, construction, operation, closure and monitoring of repositories. This mission includes as well a public service mission in terms of i) collection of waste of the 'small-scale nuclear activities' producers or owners (including the so-called 'household' radioactive waste, i.e. waste owned by private individuals) and ii) clean-up and rehabilitation of orphan polluted sites; - an information mission, notably through the regular publication of the National Inventory of radioactive materials and waste. This mission includes as well an active policy of dialogue with stakeholders both at national and local level. This document is the activity and financial report of the Andra for the year 2015

  12. ANDRA - National Radioactive Waste Management Agency. 2014 Activity report - Responsibility in action. Financial report 2014

    2015-01-01

    Created in 1979 within the CEA, the National Radioactive Waste Management Agency (ANDRA) was established by the December 1991 Waste Act as a public body in charge of the long-term management of all radioactive waste, under the supervision of the Ministry of Ecology, Energy, Sustainable Development and the Sea (formerly the Ministry of Industry and the Ministry of Environment), and the Ministry of Research. Its 3 basic missions were extended and their funding secured through the 2006 Planning Act: - a R and D mission to propose safe long-term solution for radioactive waste without current disposal system; this mission includes long-term storage, since the 2006 Planning Act, in order to propose interim solutions while final ones are being studied; - an industrial mission concerning, on one hand, waste acceptance criteria and control and, on the other hand, siting, construction, operation, closure and monitoring of repositories. This mission includes as well a public service mission in terms of i) collection of waste of the 'small-scale nuclear activities' producers or owners (including the so-called 'household' radioactive waste, i.e. waste owned by private individuals) and ii) clean-up and rehabilitation of orphan polluted sites; - an information mission, notably through the regular publication of the National Inventory of radioactive materials and waste. This mission includes as well an active policy of dialogue with stakeholders both at national and local level. This document is the activity and financial report of the Andra for the year 2014

  13. Alternatives evaluation of high activity radioactive wastes disposal

    Ciallella, N.R.; Petraitis, E.J.

    1989-01-01

    Different alternatives considered in the world to be used as barriers to isolate the high level radioactive from the environment wastes produced during the electric energy generation of nuclear origin are presented. Engineering and geologic barriers, are analyzed, considering nuclear fuel cycles with or without plutonium recycling; to that purpose the consideration of elements such as durability and resistance of the various engineering, availability of the fabrication processes, associated radiological impact, geological media apt to be used as geological barrier. Finally, the scopes of the Feasibility Study and Engineering draft are presented for the construction of a repository for high-level radioactive wastes, for the Argentine Nuclear Program needs, which contemplates the construction of six nuclear power plants with a potential installed towards the year 2000 GW( e ), with natural and/or lowly enriched uranium power plants and recycling of plutonium generated in the cycle. (Author) [es

  14. Competition between excitation and bleaching of thermoluminescence

    Chen, R.; Hornyak, W.F.

    1990-01-01

    The bleaching of thermoluminescence (TL) yield to a residual value by light is explained, at least in some cases, to be due to an equilibrium between excitation and de-excitation by the illuminating light. Kinetic differential equations are given governing the process for the simple case of a single trapping state for electrons and a single variety of hole recombination centre. The equations are solved numerically for chosen sets of the relevant parameters starting either from empty traps and centres or from highly populated ones. In agreement with experimental results, the numerical computation predicts that after a long enough illumination the process of filling of the traps converges to the same equilibrium value as that produced by bleaching. It is also found that the equilibrium value is independent of the intensity, though, of course, this is approached faster with more intense light. The computed dependencies of the filling of trapping states as a function of illumination time are shown. The final equilibrium value for the filling of trapping states can also be evaluated analytically for any set of given parameters; these compare very favourably with the calculated results. The change of the results with the variation of the relevant parameters is discussed. (author)

  15. Shielded analytical laboratory activities supporting waste isolation programs

    McCown, J.J.

    1985-08-01

    The Shielded Analytical Laboratory (SAL) is a six cell manipulator-equipped facility which was built in 1962 as an addition to the 325 Radiochemistry Bldg. in the 300 Area at Hanford. The facility provides the capability for handling a wide variety of radioactive materials and performing chemical dissolutions, separations and analyses on nuclear fuels, components, waste forms and materials from R and D programs

  16. Low-level dry active waste management planning for Calvert Cliffs Nuclear Power Plant

    Butler, C.N.; Feizollani, F.; Jarboe, Th.B.

    1984-01-01

    To offset the rising cost of low-level radioactive waste disposal and to provide contingency measures for disposal space unavailability after January 1, 1986, Baltimore Gas and Electric (BG and E) has undertake efforts to establish a long-term waste management program. This plan, which was developed after detailed study of a number of options, consists of four elements: management of dry active wastes; implementation of 10CFR61 requirements; storage of process wastes; and enhancement of liquid/solid waste systems and equipment performance. Each element was scheduled for implementation in accordance with an established set of priorities. Accordingly, detailed engineering for implementation of the first two elements was initiated in December of 1982. This paper focuses on BGandE's experience in implementation of the first element o the program, i.e., the management of dry active waste (DAW). DAW is managed by providing a new buildin dedicated to its handling, processing, volume-reduction, and storage. This building, which is equipped with state-of-the-art decontamination and processing techniques, allows for implementation of waste minimization and for interim storage of DAW in a safe and cost effective manner

  17. Waste management, decommissioning and environmental restoration for Canada's nuclear activities. Proceedings

    2011-01-01

    The Canadian Nuclear Society conference on Waste Management, Decommissioning and Environmental Restoration for Canada's Nuclear Activities was held in Toronto, Ontario, Canada on September 11-14, 2011. The conference provided a forum for discussion of the status and proposed future directions of technical, regularly, environmental, social and economic aspects of radioactive waste management, nuclear facility decommissioning, and environmental restoration activities for Canadian nuclear facilities. The conference included both plenary sessions and sessions devoted to more detailed technical issues. The plenary sessions were focussed on three broad themes: the overall Canadian program; low and intermediate waste; and, international perspectives. Topics of the technical sessions included: OPG's deep geologic repository for low and intermediate level waste; stakeholder interactions; decommissioning projects; uranium mine waste management; used fuel repository - design and safety assessment; federal policies, programs and oversight; regulatory considerations; aboriginal traditional knowledge; geological disposal - CRL site classification; geological disposal - modelling and engineered barriers; Port Hope Area Initiative; waste characterization; LILWM - treatment and processing; decommissioning projects and information management; international experience; environmental remediation; fuel cycles and waste processing.

  18. Waste Form Release Data Package for the 2001 Immobilized Low-Activity Waste Performance Assessment

    McGrail, B. Peter; Icenhower, Jonathan P.; Martin, Paul F.; Schaef, Herbert T.; O' Hara, Matthew J.; Rodriguez, Eugenio; Steele, Jackie L.

    2001-02-01

    This data package documents the experimentally derived input data on the representative waste glasses LAWABP1 and HLP-31 that will be used for simulations of the immobilized lowactivity waste disposal system with the Subsurface Transport Over Reactive Multiphases (STORM) code. The STORM code will be used to provide the near-field radionuclide release source term for a performance assessment to be issued in March of 2001. Documented in this data package are data related to 1) kinetic rate law parameters for glass dissolution, 2) alkali-H ion exchange rate, 3) chemical reaction network of secondary phases that form in accelerated weathering tests, and 4) thermodynamic equilibrium constants assigned to these secondary phases. The kinetic rate law and Na+-H+ ion exchange rate were determined from single-pass flow-through experiments. Pressurized unsaturated flow and vapor hydration experiments were used for accelerated weathering or aging of the glasses. The majority of the thermodynamic data were extracted from the thermodynamic database package shipped with the geochemical code EQ3/6. However, several secondary reaction products identified from laboratory tests with prototypical LAW glasses were not included in this database, nor are the thermodynamic data available in the open literature. One of these phases, herschelite, was determined to have a potentially significant impact on the release calculations and so a solubility product was estimated using a polymer structure model developed for zeolites. Although this data package is relatively complete, final selection of ILAW glass compositions has not been done by the waste treatment plant contractor. Consequently, revisions to this data package to address new ILAW glass formulations are to be regularly expected.

  19. Where, when, how: the place of radioactive wastes in France. Andra, 1998 activity report

    1998-01-01

    The 1998 activity report of the French national agency of radioactive wastes (Andra) presents successively: the role and missions of the Andra (history, status of radioactive wastes in France, surface storage and know-how, underground research laboratories, site selection and public information); the aspects of safety (inventory, identification and labelling of wastes, environmental policy, public relation, safety rules and reports, information storage); the scientific programs (collaborations, financing, site studies, rock mechanics and reversibility of storage, design of storage facilities, services); financial report. (J.S.)

  20. Performance test results of noninvasive characterization of RCRA surrogate waste by prompt gamma neutron activation analysis

    Gehrke, R.J.; Propp, W.A.

    1997-11-01

    A performance evaluation to determine the feasibility of using prompt gamma neutron activation analysis (PGNAA) for noninvasive, quantitative assay of mixed waste containers was sponsored by DOE's Office of Technology Development (OTD), the Mixed Waste Focus Area (MWFA), and the Idaho National Engineering and Environmental Laboratory (INEEL). The evaluation was conducted using a surrogate waste, based on Portland cement, that was spiked with three RCRA metals, mercury, cadmium, and lead. The results indicate that PGNAA has potential as a process monitor. However, further development is required to improve its sensitivity to meet regulatory requirements for determination of these RCRA metals

  1. Active and passive computed tomography mixed waste focus area final report

    Becker, G K; Camp, D C; Decman, D J; Jackson, J A; Martz, H E; Roberson, G P.

    1998-01-01

    The Mixed Waste Focus Area (MWFA) Characterization Development Strategy delineates an approach to resolve technology deficiencies associated with the characterization of mixed wastes. The intent of this strategy is to ensure the availability of technologies to support the Department of Energy s (DOE) mixed-waste, low-level or transuranic (TRU) contaminated waste characterization management needs. To this end the MWFA has defined and coordinated characterization development programs to ensure that data and test results necessary to evaluate the utility of non-destructive assay technologies are available to meet site contact handled waste management schedules. Requirements used as technology development project benchmarks are based in the National TRU Program Quality Assurance Program Plan. These requirements include the ability to determine total bias and total measurement uncertainty. These parameters must be completely evaluated for waste types to be processed through a given nondestructive waste assay system constituting the foundation of activities undertaken in technology development projects. Once development and testing activities have been completed, Innovative Technology Summary Reports are generated to provide results and conclusions to support EM-30, -40, or -60 end user or customer technology selection. The active and passive computed tomography non-destructive assay system is one of the technologies selected for development by the MWFA. Lawrence Livermore National Laboratory (LLNL) has developed the active and passive computed tomography (A ampersand XT) nondestructive assay (NDA) technology to identify and accurately quantify all detectable radioisotopes in closed containers of waste. This technology will be applicable to all types of waste regardless of their classification-low level, transuranic or mixed. Mixed waste contains radioactivity and hazardous organic species. The scope of our technology is to develop a non-invasive waste-drum scanner that

  2. TWRS retrieval and storage mission. Immobilized low-activity waste disposal plan

    Shade, J.W.

    1998-01-01

    The TWRS mission is to store, treat, and immobilize highly radioactive Hanford waste (current and future tank waste and the encapsulated cesium and strontium) in a safe, environmentally sound, and cost-effective manner (TWRS JMN Justification for mission need). The mission includes retrieval, pretreatment, immobilization, interim storage and disposal, and tank closure. As part of this mission, DOE has established the TWRS Office to manage all Hanford Site tank waste activities. The TWRS program has identified the need to store, treat, immobilize, and dispose of the highly radioactive Hanford Site tank waste and encapsulated cesium and strontium materials in an environmentally sound, safe, and cost-effective manner. To support environmental remediation and restoration at the Hanford Site a two-phase approach to using private contractors to treat and immobilize the low-activity and high-level waste currently stored in underground tanks is planned. The request for proposals (RFP) for the first phase of waste treatment and immobilization was issued in February 1996 (Wagoner 1996) and initial contracts for two private contractor teams led by British Nuclear Fuels Ltd. and Lockheed-Martin Advanced Environmental Services were signed in September 1996. Phase 1 is a proof-of-concept and commercial demonstration effort to demonstrate the technical and business feasibility of using private facilities to treat Hanford Site waste, maintain radiological, nuclear, process, and occupational safety; and maintain environmental protection and compliance while reducing lifecycle costs and waste treatment times. Phase 1 production of ILAW is planned to begin in June 2002 and could treat up to about 13 percent of the waste. Phase 1 production is expected to be completed in 2007 for minimum order quantities or 2011 for maximum order quantities. Phase 2 is a full-scale production effort that will begin after Phase 1 and treat and immobilize most of the waste. Phase 2 production is

  3. The validation of waste assay systems during active test at Rokkasho Reprocessing Plant

    Tamura, Takayuki; Miura, Yasushi; Iwamoto, Tomonori

    2007-01-01

    In order to implement accurate material accountancy at Rokkasho Reprocessing Plant (RRP) as a large scale reprocessing plant, it is necessary to introduce accurate measurement systems not only for mainstream material, but also appropriate measurement systems for solid waste materials. In this sense, the generated wastes by the active test operation have been measured with the Non-Destructive Assay Systems, such as Rokkasho Hulls Measurement System (RHMS) and Waste Crate Assay System (WCAS) for accountancy. This paper describes the experience of the NDA operation and the evaluation results for accountancy. (author)

  4. Volumetric activity of SRS mixed waste and comparison with SRS performance and commercial facility limits

    Ades, M.J.; Daugherty, B.A.; Cook, J.R.

    1996-01-01

    This paper discusses the comparative analysis performed to estimate the after-treatment volumetric activity of the radionuclides included in the Savannah River site (SRS) mixed-waste streams and its comparison with the following: (1) The performance evaluation (PE) limits established for each radionuclide for on-site disposal: These limits correspond to the permissible waste disposal limits that are the lowest limits evaluated for the most restrictive release scenarios that include the groundwater pathway, the atmospheric pathway, and the intruder scenarios. (2) The radiological performance assessment (PA) limits established for each radionuclide for disposal in the SRS disposal vaults that meet the requirements of Chap. III of the U.S. Department of Energy Order 5820.2A: The vaults considered are the low-activity waste (LAW) vaults, the intermediate-level non-tritium (ILNT) vaults. and the intermediate-level tritium (ILT) vaults. (3) The radioactive limits of a commercial mixed waste disposal facility

  5. Microleakage comparison of glass-ionomer and white mineral trioxide aggregate used as a coronal barrier in nonvital bleaching.

    Vosoughhosseini, Sepideh; Lotfi, Mehrdad; Shahmoradi, Kaveh; Saghiri, Mohammad-Ali; Zand, Vahid; Mehdipour, Masoumeh; Ranjkesh, Bahram; Mokhtari, Hadi; Salemmilani, Amin; Doosti, Sirvan

    2011-11-01

    There is some evidence that the pH at the root surface is reduced by intracoronal placement of bleaching pastes, which is known to enhance osteoclastic activity. Therefore, it is recommended that a protective barrier be used over the canal filling to prevent leakage of bleaching agents. Glass-ionomer (GI) is commonly used as a coronal barrier before nonvital bleaching. Because mineral trioxide aggregate (MTA) creates high alkalinity after mixing with water, using MTA as a protective barrier over the canal filling may not only prevent leakage of bleaching agents and microorganisms, but may prevent cervical resorption. The aim of this study was to evaluate sealing ability of white mineral trioxide aggregate (WMTA) as a coronal barrier before nonvital bleaching. Root canals of one hundred thirty human maxillary incisors were instrumented and filled with gutta-percha without sealer. Gutta-percha was removed up to 3 mm below the cementoenamel junction (CEJ). The teeth were randomly divided into six experimental groups of 20 teeth each and two control groups of 5. In three experimental groups, WMTA was packed into the canal to the level of CEJ. In the remaining experimental groups, glass-ionomer (GI) was used as a coronal barrier. After a 24-hour incubation period, one of the following three bleaching agents was placed in the access cavity of each of the WMTA or GI groups. These three bleaching agents were 30% hydrogen peroxide, sodium perborate mixed with 30% hydrogen peroxide, and sodium perborate mixed with distilled water. The bleaching agents were replaced every 3 days for three times. In the positive controls, no coronal barrier was used. In the negative controls, all the tooth surfaces were covered by two layers of nail varnish. Microleakage was evaluated using protein leakage test. Statistical analyses were performed with the Kruskal-Wallis and Mann-Whitney tests. The experimental groups showed minimum leakage which was not significantly more than tha in the

  6. Detoxification of kraft pulp ECF bleaching effluents by catalytic hydrotreatment.

    Calvo, L; Gilarranz, M A; Casas, J A; Mohedano, A F; Rodríguez, J J

    2007-02-01

    Two different effluents from the D(1) and E(1) stages of the ECF bleaching of Eucalyptus globulus kraft pulp were treated by catalytic hydrogenation in a trickle bed reactor using commercial and homemade Pd/AC catalysts. The reactor was fed with the bleaching effluent and a H(2)/N(2) gas stream. The variables studied were space-time (1.4-5g(cat)min/mL), gas to liquid flow ratio (286-1000vol.), gas feed concentration (H(2):N(2), 1:1-1:7.3vol.), temperature (25-100 degrees C) and pressure (1-11bar). Hydrotreatment performance was evaluated in terms of ecotoxicity, adsorbable organic halogen (AOX), chemical oxygen demand (COD), biological oxygen demand (BOD(5)) and colour removal. In all the runs, the ecotoxicity of the effluents decreased as a result of the treatment, achieving reductions that ranged from 70% to 98%. Simultaneously to the reduction of toxicity, the hydrotreatment led to a decrease of the colour of the effluents, being the decrease significantly higher in the case of E(1) effluent. The AOX content was reduced by 85% and 23% for E(1) and D(1) effluents, respectively. In the case of D(1) effluent the removal of ecotoxicity was significantly higher than that of AOX, which indicates that much of the toxicity of the effluent must be associated to non-chlorinated organics. In spite of the important reduction of ecotoxicity, the biodegradability of the effluents only increased slightly. The homemade catalysts, prepared from activated carbons with a high external or non-microporous surface area and mesopore volume and a convenient surface chemistry showed a higher efficiency than the commercial one.

  7. DEVELOPMENT, QUALIFICATION, AND DISPOSAL OF AN ALTERNATIVE IMMOBILIZED LOW-ACTIVITY WASTE FORM AT THE HANFORD SITE

    Sams, T.L.; Edge, J.A.; Swanberg, D.J.; Robbins, R.A.

    2011-01-01

    Demonstrating that a waste form produced by a given immobilization process is chemically and physically durable as well as compliant with disposal facility acceptance criteria is critical to the success of a waste treatment program, and must be pursued in conjunction with the maturation of the waste processing technology. Testing of waste forms produced using differing scales of processing units and classes of feeds (simulants versus actual waste) is the crux of the waste form qualification process. Testing is typically focused on leachability of constituents of concern (COCs), as well as chemical and physical durability of the waste form. A principal challenge regarding testing immobilized low-activity waste (ILAW) forms is the absence of a standard test suite or set of mandatory parameters against which waste forms may be tested, compared, and qualified for acceptance in existing and proposed nuclear waste disposal sites at Hanford and across the Department of Energy (DOE) complex. A coherent and widely applicable compliance strategy to support characterization and disposal of new waste forms is essential to enhance and accelerate the remediation of DOE tank waste. This paper provides a background summary of important entities, regulations, and considerations for nuclear waste form qualification and disposal. Against this backdrop, this paper describes a strategy for meeting and demonstrating compliance with disposal requirements emphasizing the River Protection Project (RPP) Integrated Disposal Facility (IDF) at the Hanford Site and the fluidized bed steam reforming (FBSR) mineralized low-activity waste (LAW) product stream.

  8. Supplement analysis of transuranic waste characterization and repackaging activities at the Idaho National Engineering Laboratory in support of the Waste Isolation Pilot Plant test program

    1991-03-01

    This supplement analysis has been prepared to describe new information relevant to waste retrieval, handling, and characterization at the Idaho National Engineering Laboratory (INEL) and to evaluate the need for additional documentation to satisfy the National Environmental Policy Act (NEPA). The INEL proposes to characterize and repackage contact-handled transuranic waste to support the Waste Isolation Pilot Plant (WIPP) Test Phase. Waste retrieval, handling and processing activities in support of test phase activities at the WIPP were addressed in the Supplemental Environmental Impact Statement (SEIS) for the WIPP. To ensure that test-phase wastes are properly characterized and packaged, waste containers would be retrieved, nondestructively examined, and transported from the Radioactive Waste Management Complex (RWMC) to the Hot-Fuel Examination Facility for headspace gas analysis, visual inspections to verify content code, and waste acceptance criteria compliance, then repackaging into WIPP experimental test bins or returned to drums. Following repackaging the characterized wastes would be returned to the RWMC. Waste characterization would help DOE determine WIPP compliance with US Environmental Protection Agency regulations governing disposal of transuranic waste and hazardous waste. Additionally, this program supports onsite compliance with Resource Conservation and Recovery Act (RCRA) requirements, compliance with the terms of the No-Migration Variance at WIPP, and provides data to support future waste shipments to WIPP. This analysis will help DOE determine whether there have been substantial changes made to the proposed action at the INEL, or if preparation of a supplement to the WIPP Final Environmental Impact Statement (DOE, 1980) and SEIS (DOE, 1990a) is required. This analysis is based on current information and includes details not available to the SEIS

  9. Historically Black Colleges and Universities Radioactive Waste Management Research Program: Summary of activities, 1985-1986

    1986-01-01

    This report summarizes the 1985 to 1986 activities of the Historically Black Colleges and Universities (HBCUs) Radioactive Waste Management Research Program sponsored by the Office of Civilian Radioactive Waste Management of the US Department of Energy (DOE). The first set of three awards was made in September,1984. In September, 1985, two of these projects were renewed and a new proposal was funded. The program has been enthusiastically received by the community of HBCUs and the program sponsor

  10. Multiple containment for LSA [low specific activity] and SCO [surface contaminated objects] wastes

    Burgess, M.H.

    1993-09-01

    Radioactive wastes are generally transported in the form of Low Specific Activity (LSA) materials or Surface Contaminated Objects (SCO). This report proposes that a method of acknowledging the beneficial effects of multiple containment for such wastes should be written into the 1996 Edition of the IAEA Transport Regulations. Experience used to assess risks from on-site movements of radioactive material in the UK can be applied to develop safety arguments justifying the alleviation of off-site transport risks. (UK)

  11. 'In vitro' assessment to instrumented indentation hardness tests in enamel of bovine teeth, before and after dental bleaching by laser

    Britto Junior, Francisco Meira

    2004-01-01

    The laser enamel bleaching is a common used procedure due to its satisfactory esthetic results. The possible changes on the dental structures caused by the bleaching technique are of great importance. The enamel superficial microhardness changes through instrumented indentation hardness on bovine teeth were analyzed in this present study. The samples were divided in two halves, one being the control and the other irradiated with a diode laser (808 nm) or with a Nd:YAG laser (1064 nm) to activate the Whiteness HP bleaching gel (hydrogen peroxide at 35%). It was possible to conclude that there was a statistical significant increase on the enamel superficial microhardness (Group I, sample 1 and Group II, sample 1) despite this increase did not seem to indicate a concern regarding the enamel surface resistance change. There was not a significant statistical change on the enamel microhardness on the other samples. The final conclusion is that there was no superficial enamel morphological change after these treatments. (author)

  12. Thermal bleaching of the V-centres in gamma irradiated KCl:Ca and KCl:Sr crystals

    Georgiev, G.; Popov, P.; Bakalova, N.

    1982-01-01

    The thermal bleaching of the Vsub(2)sup(M)-and F-bands in gamma irradiated KCl:Ca and KCl:Sr has been investigated under a linear heating with rate of 1 K/min in the temperature range from 270K up to 470K. The results show that during the bleaching the ratio between the concentrations of the F-and Vsub(2)sup(M)-centers is constant. Under the supposition that the ratio is equal to 2, oscillator strenghts of 0.61 and 0.70 have been obtained for the Vsub(2)sup(M)-centre in KCl:Sr, respectively. From the derivatives of the bleaching curves the activation energies and frequency factors for the Vsub(2)sup(M)-centre destruction has been obtained as well. (authors)

  13. Efficacy and persistence of tooth bleaching using a diode laser with three different treatment regimens.

    Al Quran, Firas A M; Mansour, Yasar; Al-Hyari, Sabaa; Al Wahadni, Ahed; Mair, Lawrence

    2011-01-01

    Studies have measured the effectiveness of tooth bleaching, however there are very few studies that have measured the persistence in color change after a 6-month follow-up. This study assessed the efficacy of the laser bleaching process using different regimens, and the persistence of color change over a 6-month period. Sixty patients divided into three equal groups were subjected to bleaching using a diode laser with 34% hydrogen peroxide. Group 1: patients subjected to one session of laser bleaching. Group 2: patients subjected to two sessions of laser bleaching with a 1-week interval. Group 3: the same as Group 2 but followed by home bleaching once a month for 3 months. The color was assessed four times: before bleaching, directly after bleaching, 3 months after bleaching, and 6 months after bleaching. All teeth had a significant color change at 6 months, but all teeth had regressed from the maximum value. There was significantly less regression in color for Group 3, followed by Groups 2 and 1, respectively. The combined technique of in-office laser bleaching for two sessions with a 1-week interval, followed by home bleaching once a month for 3 months gave more persistence in color change. In-office power bleaching using a laser assisted hydrogen peroxide system repeated after a week, combined with home bleaching once a month for 3 months, is an effective bleaching regimen with less color regression after 6 months compared to a regimen of in-office bleaching alone.

  14. Considerations for an active and passive scanner to assay nuclear waste drums

    Martz, H.E.; Azevedo, S.G.; Roberson, G.P.; Schneberk, D.J.; Koenig, Z.M.; Camp, D.C.

    1990-01-01

    Radioactive wastes are generated at many DOE laboratories, military facilities, fuel fabrication and enrichment plants, reactors, hospitals, and university research facilities. At all of these sites, wastes must be separated, packaged, categorized, and packed into some sort of container--usually 208-L (55-gal) drums--for shipment to waste-storage sites. Prior to shipment, the containers must be labeled, assayed, and certified; the assay value determines the ultimate disposition of the waste containers. An accurate nondestructive assay (NDA) method would identify all the radioisotopes present and provide a quantitative measurement of their activity in the drum. In this way, waste containers could be routed in the most cost-effective manner and without having to reopen them. Currently, the most common gamma-ray method used to assay nuclear waste drums is segmented gamma-ray scanning (SGS) spectrometer that crudely measures only the amount of 235 U or 239 Pu present in the drum. This method uses a spatially-averaged, integrated, emitted gamma-ray-intensity value. The emitted intensity value is corrected by an assumed constant-attenuation value determined by a spatially-averaged, transmission (or active) measurement. Unfortunately, this typically results in an inaccurate determination of the radioactive activities within a waste drum because this measurement technique is valid only for homogeneous-attenuation or known drum matrices. However, since homogeneous-attenuation matrices are not common and may be unknown, other NDA techniques based on active and Passive CT (A ampersand PCT) are under development. The active measurement (ACT) yields a better attenuation matrix for the drum, while the passive measurement (PCT) more accurately determines the identity of the radioisotopes present and their activities. 9 refs., 2 figs

  15. Generation and management of solid waste resulting from tourist activities of the Porto de Galinhas - P

    Jaqueline Guimarães Santos

    2015-04-01

    Full Text Available The significant solid waste generation, coupled with the lack of proper management of the waste generated, has been one of the issues of concern and conducting research on the part of scholars in the field. Tourism as an activity that positively impacts and negativity a given location, has emerged as an activity that can generate a lot of waste, especially in periods of high season, considering the increase of people moving to the tourist destinations. Accordingly, this study aims to analyze the generation and management of solid waste resulting from tourism in Porto de Galinhas, PE. We performed an exploratory, descriptive, qualitative study, conducted in the form of a case study in Porto de Galinhas, PE. The data collection was done interviews together social actors, as well as non-participant observation during data collection. The results showed that tourism activities in Porto de Galinhas result in a high amount of solid waste, and these are directed to inappropriate places. Although fate presents a combination of recyclable materials, RECYCLE, reuses this not a significant amount, given the proportion of waste generated.

  16. 40 CFR 60.1370 - What records must I keep for municipal waste combustion units that use activated carbon?

    2010-07-01

    ... waste combustion unit at your plant. Include supporting calculations. (b) Records of low carbon feed... waste combustion units that use activated carbon? 60.1370 Section 60.1370 Protection of Environment... SOURCES Standards of Performance for Small Municipal Waste Combustion Units for Which Construction is...

  17. Bleaching and recovery of a phototrophic bioeroding sponge

    Marlow, Joseph; Davy, Simon K.; Shaffer, Megan; Haris, Abdul; Bell, James J.

    2018-06-01

    In the Wakatobi region of Indonesia, a prolonged period of elevated water temperature in 2016 caused extensive coral bleaching and mortality. Unusually, bleaching was also observed in the bioeroding sponge Cliona aff. viridis, with affected sponges expelling 99% of their Symbiodinium. Bleaching surveys of C. aff. viridis were conducted 6 weeks apart, coinciding with a 0.8 °C drop in water temperature. Over this period, bleaching prevalence dropped from 73.9% (± 9.9 SE) to 25.7% (± 5.8 SE), and bleaching severity dropped from 25.95% (± 4.5 SE) to 11.54% (± 1.9 SE) of sponge tissue. Over the same period, monitored bleached sponges showed an 81% drop in bleaching severity, but also a 13% reduction in overall sponge size. Our results show that while the clionaid- Symbiodinium relationship is susceptible to break down under thermal stress, rapid recovery can occur, although incurring some partial host mortality.

  18. Evaluation of peanut hulls as an alternative to bleaching clays

    Hassanein, M. M.; El-Shami, S. M.; Taha, F. S.

    2011-07-01

    Peanut hulls (PNH) were carbonized at different temperatures, times, and evaluated at different concentrations as an alternative to bleaching clays. Evaluation of bleached crude soybean oil with PNH was based on their delta free fatty acids, reduction in peroxide value (PV), reduction in phospholipids (PL) and bleachability. The performance of several commercially used bleaching clays was evaluated, for comparison. Mixtures were formulated including: PNH and Tonsil -N (TN), PNH and Fuller's earth (FE) and PNH and O-passive (OP) and examined. The oxidative stability of oils was determined. Results for the investigated commercial bleaching clays revealed: TN > FE > F > TF > OP. Highest reduction in PV and PL, and highest bleachability were achieved for soybean oil bleached with 2% PNH carbonized at 500 degree centigrade for 30 min (PNH). Mixtures of PNH with the three chosen bleaching clays indicated that 1PNH : 2TN gave the highest bleachability. CSO was miscella bleached in hexane using PNH and resulted in an appreciable improvement in all oil characteristics, especially in bleachability. Oxidative stability of oils was in the following order: TN > control > FE > PNH with Induction period values of 23.1 > 6.43 > 5.73 > 2.85 h, respectively. (Author) 20 refs.

  19. Bleaching of F-type centres in alkali halides

    Chandratillake, M.R.; Newton, G.W.A.; Robinson, V.J.

    1984-01-01

    Bleaching of the F band in KCl occurs on pulsing with 532 nm laser light. The bleaching is accompanied by the appearance of an absorption on the red side of the F band. Both bleaching and absorption are transient phenomena, and no permanent bleaching or absorption is observed. The same exponential lifetime of about 5μS was obtained for both bleaching and absorption, and all the features were found to be independent of both temperature (between 200 and 300 K) and the intensity of the analysing light. This eliminates the possibility of a trapped species, such as F - , being responsible. The phenomena are qualitatively different from the bleaching observed at low light intensity, where bleaching of the F band is accompanied by formation of F - , which is thermally stable below 250 K. The most likely explanation of the results is that the high concentration of conduction band electrons following the laser pulse allows formation of free or quasi-free electron pairs, e 2 - , which decay back into F centres on a time scale which is long compared with that for individual electrons. (author)

  20. Determination of burial dose in incompletely bleached fluvial samples using single grains of quartz

    Thomsen, Kristina Jørkov; Murray, A.S.; Bøtter-Jensen, Lars

    2007-01-01

    We determine the burial dose in three known-age incompletely bleached fluvial samples using single grains of quartz. Estimation of burial dose in incompletely bleached samples requires that the characteristics of the well-bleached part of the distribution are known in order to distinguish between...... well-bleached and poorly bleached grains. It is especially important to investigate if the uncertainties assigned to individual estimates of dose adequately describe the observed variability in well-bleached dose distributions. We investigate this by quantifying the overdispersion in laboratory-bleached...

  1. Bench scale experiments for the remediation of Hanford Waste Treatment Plant low activity waste melter off-gas condensate

    Taylor-Pashow, Kathryn M.L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Poirier, Michael [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, Daniel J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-08-11

    The Low Activity Waste (LAW) vitrification facility at the Hanford Waste Treatment and Immobilization Plant (WTP) will generate an aqueous condensate recycle stream (LAW Off-Gas Condensate) from the off-gas system. The plan for disposition of this stream during baseline operations is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. The primary reason to recycle this stream is so that the semi-volatile 99Tc isotope eventually becomes incorporated into the glass. This stream also contains non-radioactive salt components that are problematic in the melter, so diversion of this stream to another process would eliminate recycling of these salts and would enable simplified operation of the LAW melter and the Pretreatment Facilities. This diversion from recycling this stream within WTP would have the effect of decreasing the LAW vitrification mission duration and quantity of glass waste. The concept being tested here involves removing the 99Tc so that the decontaminated aqueous stream, with the problematic salts, can be disposed elsewhere.

  2. Waste production and regional growth of marine activities an econometric model

    Bramati, Maria Caterina

    2016-01-01

    Coastal regions are characterized by intense human activity and climatic pressures, often intensified by competing interests in the use of marine waters. To assess the effect of public spending on the regional economy, an econometric model is here proposed. Not only are the regional investment and the climatic risks included in the model, but also variables related to the anthropogenic pressure, such as population, economic activities and waste production. Feedback effects of economic and demographic expansion on the pollution of coastal areas are also considered. It is found that dangerous waste increases with growing shipping and transportation activities and with growing population density in non-touristic coastal areas. On the other hand, the amount of non-dangerous wastes increases with marine mining, defense and offshore energy production activities. However, lower waste production occurs in areas where aquaculture and touristic industry are more exploited, and accompanied by increasing regional investment in waste disposal. - Highlights: • We use an econometric model as a tool for assessing the effects of regional policies on the development of economic activities related to the use of the sea and on the impact on the marine environment. • Through scenario simulation we provide strategic guidelines for policy makers and economic planners • The model features feedback effects of economic and demographic expansion on the pollution of coastal areas.

  3. Aerobic composting of waste activated sludge: Kinetic analysis for microbiological reaction and oxygen consumption

    Yamada, Y.; Kawase, Y.

    2006-01-01

    In order to examine the optimal design and operating parameters, kinetics for microbiological reaction and oxygen consumption in composting of waste activated sludge were quantitatively examined. A series of experiments was conducted to discuss the optimal operating parameters for aerobic composting of waste activated sludge obtained from Kawagoe City Wastewater Treatment Plant (Saitama, Japan) using 4 and 20 L laboratory scale bioreactors. Aeration rate, compositions of compost mixture and height of compost pile were investigated as main design and operating parameters. The optimal aerobic composting of waste activated sludge was found at the aeration rate of 2.0 L/min/kg (initial composting mixture dry weight). A compost pile up to 0.5 m could be operated effectively. A simple model for composting of waste activated sludge in a composting reactor was developed by assuming that a solid phase of compost mixture is well mixed and the kinetics for microbiological reaction is represented by a Monod-type equation. The model predictions could fit the experimental data for decomposition of waste activated sludge with an average deviation of 2.14%. Oxygen consumption during composting was also examined using a simplified model in which the oxygen consumption was represented by a Monod-type equation and the axial distribution of oxygen concentration in the composting pile was described by a plug-flow model. The predictions could satisfactorily simulate the experiment results for the average maximum oxygen consumption rate during aerobic composting with an average deviation of 7.4%

  4. Removing polysaccharides-and saccharides-related coloring impurities in alkyl polyglycosides by bleaching with the H2O2/TAED/NaHCO3 system.

    Yanmei, Liu; Jinliang, Tao; Jiao, Sun; Wenyi, Chen

    2014-11-04

    The effect of H2O2/TAED/NaHCO3 system, namely NaHCO3 as alkaline agent with the (tetra acetyl ethylene diamine (TAED)) TAED-activated peroxide system, bleaching of alkyl polyglycosides solution was studied by spectrophotometry. The results showed that the optimal bleaching conditions about H2O2/TAED/NaHCO3 system bleaching of alkyl polyglycosides solution were as follows: molar ratio of TAED to H2O2 was 0.06, addition of H2O2 was 8.6%, addition of NaHCO3 was 3.2%, bleaching temperature of 50-65 °C, addition of MgO was 0.13%, and bleaching time was 8h. If too much amount of NaHCO3 was added to the system and maintained alkaline pH, the bleaching effect would be greatly reduced. Fixing molar ratio of TAED to H2O2 and increasing the amount of H2O2 were beneficial to improve the whiteness of alkyl polyglycosides, but adding too much amount of H2O2 would reduce the transparency. In the TAED-activated peroxide system, NaHCO3 as alkaline agent and buffer agent, could overcome the disadvantage of producing black precipitates when NaOH as alkaline agent. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Initial Selection of Supplemental Treatment Technologies for Hanford's Low-Activity Tank Waste

    Raymond, Richard E.; Powell, Roger W.; Hamilton, Dennis W.; Kitchen, William A.; Mauss, Billie M.; Brouns, Thomas M.

    2004-01-01

    In 2002, the U.S. Department of Energy (DOE) documented a plan for accelerating cleanup of the Hanford Site, located in southeastern Washington State, by at least 35 years (DOE 2002). A key element of the accelerated cleanup plan was a strategic initiative for acceleration of the tank waste program and completion of ''tank waste treatment by 2028 by increasing the capacity of the planned Waste Treatment Plant (ETP) and using supplemental technologies for waste treatment and immobilization''. The plan identified specific technologies to be evaluated for supplemental treatment of as much as 70% of the low-activity waste (LAW). The objective was to complete required testing and evaluation that would ''...bring an appropriate combination of the above technologies to deployment to supplement LAW treatment and immobilization in the WTP to achieve the completion of tank waste treatment by 2028''. In concert with this acceleration plan, DOE, the U.S. Environmental Protection Agency, and the Washington State Department of Ecology have proposed to accelerate from 2012 to 2005 the Hanford Federal Facility Compliance Agreement (Tri-Party Agreement) milestone (M-62-08) associated with a final decision on treatment of the balance of tank waste that is beyond the capacity of the currently designed WTP

  6. Vitrification of Three Low-Activity Radioactive Waste Streams from Hanford

    Ferrara, D.M.; Crawford, C.L.; Ha, B.C.; Bibler, N.E.

    1998-09-01

    As part of a demonstration for British Nuclear Fuels Limited, Incorporated (BNFL), the Immobilization Technology Section (ITS) of the Savannah River Technology Center (SRTC) has produced and characterized three low-activity waste (LAW) glasses from Hanford radioactive waste samples. The three LAW glasses were produced from radioactive supernate samples that had been treated by the Waste Processing Technology Section (WPTS) at SRTC to remove most of the radionuclides. These three glasses were produced by mixing the waste streams with between four and nine glass-forming chemicals in platinum/gold crucibles and heating the mixture to between 1120 and 1150 degrees C. Compositions of the resulting glass waste forms were close to the target compositions. Low concentrations of radionuclides in the LAW feed streams and, therefore, in the glass waste forms supported WPTS conclusions that pretreatment had been successful. No crystals were detected in the LAW glasses. In addition, all glass waste forms passed the leach tests that were performed. These included a 20 degrees C Product Consistency Test (PCT) and a modified version of the United States Environmental Protection Agency Toxicity Characteristic Leaching Procedure (TCLP)

  7. Nova tecnologia de branqueamento de celulose adaptada ao fechamento do circuito de água A novel bleaching technology adapted to partial bleach plant closure

    Marcelo Moreira Costa

    2006-02-01

    (EOPD(EPD and D(EOPDP, respectively. The mill has an activated sludge effluent treatment plant comprised of two aeration tanks with 20,000 m3 and it is equipped with superficial aerators followed by four secondary clarifiers (two for each reactor. In the last decades, CENIBRA has been optimizing and changing its processes in order to improve environmental performance. Aiming at decreasing effluent volume, COD and AOX loads, the Ahot(EOPD(PO sequence has been proposed and evaluated in lab-scale trials, with partial filtrate recycling. This paper proposes a filtrate recycling scheme that reduces bleach plant effluent volume by 9 m3/adt (air dry ton, i.e., about 50% of the total. The filtrate saved is partially diverted to the recausticizing cycle and to post oxygen washers. The reutilization of the Ahot filtrate in the recausticizing cycle to replace the filtrates currently used to wash lime mud and dregs was shown suitable. The impact of NPE´s in the calcium cycle was not significant. This strategy allowed a recovery of c.a. 12 kg NaOH/adt of pulp that would otherwise be wasted. Pulp bleachability and quality was not significantly affected. The discharged effluent coming from D(PO stages (about 50% showed low color, COD and AOX loads, and good bio-treatability (DBO5/COD.

  8. Solid Waste Educational Resources and Activities: Let's Reduce, Reuse, and Recycle. [CD-ROM].

    Environmental Protection Agency, Washington, DC. Solid Waste and Emergency Response.

    This contains games, activities, publications, and resources for students and teachers on how to reduce, reuse, recycle, and properly manage waste. It also contains a screen saver featuring runners-up from the Earth Day 2000 art contest. Activities and games include titles such as "Planet Protectors,""Recycle City,""Trash…

  9. All "Trashed" Out: An Activity Guide to Solid Waste Management for Grades K-6.

    Illinois Univ., Springfield. Center for Solid Waste Management and Research, Springfield.

    This activity guide, specifically designed for Illinois classrooms but adaptable for other states, seeks to encourage primary students to make their own personal statement and responses to the environment through increased awareness of reducing, reusing, recycling, and composting of solid waste materials. The activities incorporate environmental…

  10. Assessing Waste Water Treatment Plant Effluents For Thyroid Hormone Disrupting Activity

    Much information has been coming to light on the estrogenic and androgenic activity of chemicals present in the waste water stream and in surface waters, but much less is known about the presence of chemicals with thyroid activity. To address this issue, we have utilized two ass...

  11. Analysis of waste management issues arising from a field study evaluating decontamination of a biological agent from a building.

    Lemieux, P; Wood, J; Drake, J; Minamyer, S; Silvestri, E; Yund, C; Nichols, T; Ierardi, M; Amidan, B

    2016-01-01

    The Bio-response Operational Testing and Evaluation (BOTE) Project was a cross-government effort designed to operationally test and evaluate a response to a biological incident (release of Bacillus anthracis [Ba] spores, the causative agent for anthrax) from initial public health and law enforcement response through environmental remediation. The BOTE Project was designed to address site remediation after the release of a Ba simulant, Bacillus atrophaeus spp. globigii (Bg), within a facility, drawing upon recent advances in the biological sampling and decontamination areas. A key component of response to a biological contamination incident is the proper management of wastes and residues, which is woven throughout all response activities. Waste is generated throughout the response and includes items like sampling media packaging materials, discarded personal protective equipment, items removed from the facility either prior to or following decontamination, aqueous waste streams, and materials generated through the application of decontamination technologies. The amount of residual contaminating agent will impact the available disposal pathways and waste management costs. Waste management is an integral part of the decontamination process and should be included through "Pre-Incident" response planning. Overall, the pH-adjusted bleach decontamination process generated the most waste from the decontamination efforts, and fumigation with chlorine dioxide generated the least waste. A majority of the solid waste generated during pH-adjusted bleach decontamination was the nonporous surfaces that were removed, bagged, decontaminated ex situ, and treated as waste. The waste during the two fumigation rounds of the BOTE Project was associated mainly with sampling activities. Waste management activities may represent a significant contribution to the overall cost of the response/recovery operation. This paper addresses the waste management activities for the BOTE field test

  12. Levels for the specific activity at disposing low-level contaminated municipal wastes

    Poschner, J.; Schaller, G.

    1995-01-01

    Using radioecological models, nuclide specific values were calculated for the specific activity of low contaminated radioactive waste, which is disposed in conventional waste deposits or burned in incineration plants. The calculation of these values is based on a limit of 10 μSv effective dose in one year, i.e. effective dose possibly resulting from waste disposal or burning should not exceed a 'de-minimis'-value of some 10 μSv per year. The applied radioecological models describe exposure of the public by direct radiation, inhalation and ingestion for the operational period of a deposit or an incineration plant, but also cover post-operational scenarios, collecting and sorting of waste and road accidents of the waste-truck. Referring to the dose limit of 10 μSv/a, a value for the specific activity of waste was calculated for each scenario and each radionuclide considered. The smallest of these values for a radionuclide, the 'basic value' was rounded to a 'reference value'. For about 600 radionuclides reference values were derived. About 90% of the reference values are ranging between 1 and 1 000 Bq/g. For about 90% of the radionuclides direct radiation or inhalation at the deposit proved to be the critical path of exposure. (orig.) [de

  13. Status on the regulatory aspects in NORM/TENORM activities and waste in Malaysia

    Hassan, Hasmadi

    2005-01-01

    In Malaysia, waste associated with TENORM are generated mostly in the tin mining and smelting, processing of minerals, and oil and gas industry. As one of a major tin producer in the world and the country current activities in oil production, the amount of waste generated in this kind of activities is quite substantial. Currently the government of Malaysia did not provide any provision in the law specifically for the exclusion of TENORM waste, however, the government did imposed the criteria for exclusion of this waste by adopting the guideline limit established by the IAEA safety series 26, which is very vital for the regulatory body i.e. Atomic Energy Licensing Board (AELB) to overcome the problems in managing some of waste related to TENORM industries. As one example, this guideline has been applied to one of the mineral processing industries in the country on decommissioning and disposing of their waste. Furthermore, due to economic reason and price of tin and its by-product is not viable and profitable so much, making this industry not significant in business and trade industries, several practices have been exempted from the regulatory control under the Atomic Energy Licensing Act, 1984. (author)

  14. Regulation of apoptotic pathways by Stylophora pistillata (Anthozoa, Pocilloporidae to survive thermal stress and bleaching.

    Hagit Kvitt

    Full Text Available Elevated seawater temperatures are associated with coral bleaching events and related mortality. Nevertheless, some coral species are able to survive bleaching and recover. The apoptotic responses associated to this ability were studied over 3 years in the coral Stylophora pistillata from the Gulf of Eilat subjected to long term thermal stress. These include caspase activity and the expression profiles of the S. pistillata caspase and Bcl-2 genes (StyCasp and StyBcl-2-like cloned in this study. In corals exposed to thermal stress (32 or 34°C, caspase activity and the expression levels of the StyBcl-2-like gene increased over time (6-48 h and declined to basal levels within 72 h of thermal stress. Distinct transcript levels were obtained for the StyCasp gene, with stimulated expression from 6 to 48 h of 34°C thermal stress, coinciding with the onset of bleaching. Increased cell death was detected in situ only between 6 to 48 h of stress and was limited to the gastroderm. The bleached corals survived up to one month at 32°C, and recovered back symbionts when placed at 24°C. These results point to a two-stage response in corals that withstand thermal stress: (i the onset of apoptosis, accompanied by rapid activation of anti-oxidant/anti-apoptotic mediators that block the progression of apoptosis to other cells and (ii acclimatization of the coral to the chronic thermal stress alongside the completion of symbiosis breakdown. Accordingly, the coral's ability to rapidly curb apoptosis appears to be the most important trait affecting the coral's thermotolerance and survival.

  15. Egyptian Environmental Activities and Regulations for Management of Hazardous Substances and Hazardous Wastes

    El Zarka, M.

    1999-01-01

    A substantial use of hazardous substances is essential to meet the social and economic goals of the community in Egypt. Agrochemicals are being used extensively to increase crop yield. The outdated agrochemicals and their empty containers represent a serious environmental problem. Industrial development in different sectors in Egypt obligates handling of huge amounts of hazardous substances and hazardous wastes. The inappropriate handling of such hazardous substances creates several health and environmental problems. Egypt faces many challenges to control safe handling of such substances and wastes. Several regulations are governing handling of hazardous substances in Egypt. The unified Environmental Law 4 for the year 1994 includes a full chapter on the Management of Hazardous Substances and Hazardous Wastes. National and international activities have been taken to manage hazardous substances and hazardous wastes in an environmental sound manner

  16. Will vitrified high active reactor waste be deposited on the seabed

    Koksvik, R.M.

    1978-01-01

    The NRPB in the UK has carried out a preliminary study on the consequences of the disposal of high active waste on the ocean bed at great depths. This is reported in 'Assessment of the radiological protection aspects of disposal of high level waste on the ocean floor', by P.D. Grimswood and G.A.M. Webb (NRPB-R 48). This report is here briefly summarised and commented on. It deals with the radiological consequences to man of the erosion and corrosion of glassified (vitrified) radioactive waste, in the deep (>4000m) ocean, radionuclide migration and path ways to man. The conclusion is that considerations of radiological protection do not preclude the disposal of specially treated radioactive waste on the ocean bed. (JIW)

  17. A mobile system for treating low-salinity low-activity liquid wastes

    Sobolev, I.A.; Timofeev, E.M.; Panteleev, V.I.; Karlin Yu.V.; Kropotov, V.N.; Slastennikov, Yu.T.; Chuikov, V.Yu.; Demkin, V.I.; Rozhkov, V.T.

    1993-01-01

    Radioactive wastes are produced not only in radiochemical production and nuclear power stations but also in numerous research institutes and industrial organizations. The specific activities of these wastes are low, and the volumes do not exceed a few dozen cubic meters a year at each individual organization, but processing such territorially distributed wastes is complicated. This particularly applies to liquid wastes, whose transportation involves a high risk of contamination if the sealing fails. As a rule, liquid wastes are solidified before transportation to a storage site. In some cases, that simplified approach leads to an unduly large consumption of solidifying materials, and particularly to an increase in volume, while storage is an expensive technique. A considerable volume reduction in the wastes to be stored is provided by processing the liquid wastes to concentrate the radionuclides in a small volume, with the main volume of treated water discharged to the drains. Two styles are possible: a stationary plant for processing wastes at each institution or a mobile one with a centralized service base, e.g., at the storage site. Mobile systems have been reported in world practice, although there is no detailed information on them. From the economic viewpoint, the second approach is preferable because it enables one to conduct such operations with fewer plants and fewer staff. That a mobile concept that was used at the Moscow Radon Cooperative in 1985 in processing liquid wastes at regional storage locations is summarized in this article. Research and development led in 1989 to the manufacture of a prototype mobile system mounted on an MAZ articulated vehicle, which included three basic modules: ultrafiltration, electrodialysis, and filtration ones. Each module is located on a separate framework and is connected to the others by reinforced rubber hoses

  18. PROMETHEE: An Alpha Low Level Waste Assay System Using Passive and Active Neutron Measurement Methods

    Passard, Christian; Mariani, Alain; Jallu, Fanny; Romeyer-Dherbey, Jacques; Recroix, Herve; Rodriguez, Michel; Loridon, Joel; Denis, Caroline; Toubon, Herve

    2002-01-01

    The development of a passive-active neutron assay system for alpha low level waste characterization at the French Atomic Energy Commission is discussed. Less than 50 Bq[α] (about 50 μg Pu) per gram of crude waste must be measured in 118-l 'European' drums in order to reach the requirements for incinerating wastes. Detection limits of about 0.12 mg of effective 239 Pu in total active neutron counting, and 0.08 mg of effective 239 Pu coincident active neutron counting, may currently be detected (empty cavity, measurement time of 15 min, neutron generator emission of 1.6 x 10 8 s -1 [4π]). The most limiting parameters in terms of performances are the matrix of the drum - its composition (H, Cl...), its density, and its heterogeneity degree - and the localization and self-shielding properties of the contaminant

  19. New insights into co-digestion of activated sludge and food waste: Biogas versus biofertilizer.

    Ma, Yingqun; Yin, Yao; Liu, Yu

    2017-10-01

    This study explored two holistic approaches for co-digestion of activated sludge and food waste. In Approach 1, mixed activated sludge and food waste were first hydrolyzed with fungal mash, and produced hydrolysate without separation was directly subject to anaerobic digestion. In Approach 2, solid generated after hydrolysis of food waste by fungal mash was directly converted to biofertilizer, while separated liquid with high soluble COD concentration was further co-digested with activated sludge for biomethane production. Although the potential energy produced from Approach 1 was about 1.8-time higher than that from Approach 2, the total economic revenue generated from Approach 2 was about 1.9-fold of that from Approach 1 due to high market value of biofertilizer. It is expected that this study may lead to a paradigm shift in biosolid management towards environmental and economic sustainability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Electrolysis of Gold from Filtration Waste by Means of Mechanical Activation

    Jana Ficeriová

    2012-12-01

    Full Text Available The intensification of the gold thiourea leaching from a filtration waste (Košice, Slovakia using mechanical activationas the pretreatment step has been studied. The leaching of “as-received“ sample in an acid thiourea solution resulted in 65 % Audissolution. However, after mechanical activation in a planetary mill 99 % of the gold was leached. The optimum redox potential forelectrolysis is in the range 500-523 mV for the gold extraction 99.79 % from the mechanically activated sample. The mechanicalactivation resulted in an increase of the specific surface area of the waste from 0.7 m2g-1 to a maximum value of 13.5 m2g-1. The physicochemicalchanges in the filtration waste as a consequence of mechanical activation had a pronounced influence on the subsequent goldextraction.