perchlorate Articles
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Combined bio-regeneration and ion-exchange system for perchlorate removal
In order to prove that perchlorate-laden resins could be bio-regenerated through direct contact with perchlorate-reducing bacteria (PRB), a combined bio-regeneration and ion-exchange (IX) system was operated. Two kinds of perchlorate-laden resins, nitrate-selective A520E and perchlorate-selective A530E, were successfully regenerated by PRB cultivated under anaerobic conditions. The ...
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Inhibition of bacterial perchlorate reduction by zero-valent iron
Perchlorate was reduced by a mixed bacterial culture over a pH range of 7.0–8.9. Similar rates of perchlorate reduction were observed between pH 7.0 and 8.5, whereas significantly slower reduction occurred at pH 8.9. Addition of iron metal, Fe(0), to the mixed bacterial culture resulted in slower rates of perchlorate reduction. Negligible perchlorate reduction was observed under abiotic ...
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CL-Out In Situ Bioremediation of Perchlorate
CL-Out is a consortium of facultative aerobic organisms that are well know for their ability to utilize nitrates. CL-Out is generally used for the aerobic cometabolism of PCE and other chlorinated solvents. As the half-reaction for perchlorate is close to that of nitrate, CL-Out cometabolism of perchlorate was successfully tested in the laboratory. In addition to laboratory tests, CL-Out was ...
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A comparative study of perchlorate degradation in acute toxicity and chronic toxicity
Since the discovery of perchlorate in water system, the public has been concerned about its human health effect. In practice it was reported that chronic exposure to perchlorate may lead to damage in thyroid hormone activity. This study introduced a method of perchlorate reduction, using autotrophic bacteria which utilise hydrogen as an electron donor. Two experiments were conducted to compare ...
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Perchlorate Treatment Technology Update
This issue paper has been prepared by EPA's Federal Facilities Forum to provide information about technologies available for treatment of perchlorate contamination in environmental media, including technologies that have been used to date and others that show potential for treating such contamination. Furthermore, this paper provides site-specific information on 51 projects where treatment ...
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Evaluation of nitrate and perchlorate reduction using sulfur-based autotrophic and mixotrophic denitrifying processes
The biological reduction of nitrate and perchlorate was comparatively evaluated in autotrophic and mixotrophic bioreactors using elemental sulfur and/or methanol as the energy source. The mixotrophic reactor was supplemented with methanol at CH3OH/NO3−-N ratio of 1 or 1.4. The mixotrophic reactor completely reduced perchlorate in the feed up to 1,000 μg l−1. The autotrophic reactor also ...
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Perchlorate Quantitation in Drinking Water Using Suppressed Anion Chromatography Coupled with Single Quadrupole MS
The EPA has established a Lifetime Drinking Water Health Advisory of 15 ppb for perchlorate to reduce health risks. More than 10 states in U.S. have established heath advisory levels for perchlorate in drinking water ranging from 1 to 18 ppb; for example, California and Maryland have proposed standards of 6 ppb and 1 ppb, respectively. A few quantitative methods for perchlorate have been ...
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Soy Oil ‘Walls’ Win Against Perchlorate, Texas Military Facility Gets EPA, State OK for Reuse
“The successful remediation of more than 50 years of contamination—including perchlorate—earned a 9,700-acre U. S. Navy facility the “Ready for Reuse” (RFR) Determination by the U.S. Environmental Protection Agency (EPA) and the Texas Commission on Environmental Quality (TCEQ). One hero of this accomplishment is the soybean, or to be more precise its derivative, soy oil (EOS), which cleaned up ...
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Perchlorate adsorption onto orange peel modified by cross-linking amine groups from aqueous solutions
Orange peel was made into a highly efficient bio-sorbent by modification with cross-linking amine groups for perchlorate removal. Bench-scale experiments were performed to explore the factors affecting the perchlorate adsorption onto the modified orange peel (MOP). Perchlorate could be removed effectively at a wide range of pH (from 1.5 to 11). The maximum adsorption capacity of MOP for ...
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Synthesis of nano grade ?–ferric oxide and evaluation of its catalytic properties
Ferric oxide is a well–known catalyst for the thermal decomposition of ammonium perchlorate and hence it is extensively used as ballistic modifier for ammonium perchlorate based composite solid propellants. The particle size of conventional propellant grade ferric oxide was reduced to nano levels by continuous ball milling using a planetary ball mill employing zircon balls in isopropyl alcohol. ...
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Biological treatment of ammonium perchlorate-contaminated wastewater: a review
Absolute reduction of perchlorate has proven complex owing to the diverse characteristics of the perchlorate ion. Technologies such as chemical reduction, ozone/peroxide, nanofiltration, and reverse osmosis have had limited success, high costs and are not environmentally friendly. A great deal of research and reviews on ion exchange and biodegradation have been carried out, but conditions for ...
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Novel perchlorate treatment at Edwards sparks national interest
Untitled Document People from across the nation came to Edwards on May 14 to see a new perchlorate treatment system being tested here. Associated with the use of rocket fuels at Edwards, perchlorate can cause thyroid problems and is a contaminant of concern nationwide. Approximately 80 people representing the Department of Defense, federal, state and regional regulatory ...
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Nitrate and Perchlorate Bioremediation in Ground Water
In Situ Bioremediation Eliminated Pump and Treat and Ion-Exhange Treatment Cost Site closure reached in less than half the time and at less than half the cost CL-Out bioremediation was implemented at a confidential manufacturing site to remediate nitrate and perchlorate concentrations in soil and ground water. A pump and treatment system was installed and operated for years in immediate response ...
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In Situ Remediation of Perchlorate in Soil and Groundwater, M.S. Thesis, California State University San Bernardino
This research project documents a technology assessment for in-situ bioremediation of perchlorate (ClO4-). The main goals are to compare methodologies, perform site characterization of soil and groundwater, and perform microcosm and bench scale tests. In this approach, perchlorate is reduced to chloride, requiring an electron donor. The suitability of electron donor amendments will be assessed ...
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Treatment of Perchlorate and 1,1,1-Trichloroethane in Groundwater using Edible Oil Substrate (EOS®)
ABSTRACT: Laboratory studies and a pilot-scale field test are being conducted to evaluate the use of edible oil emulsions for biodegradation of perchlorate and 1,1,1-trichloroethane (1,1,1-TCA) in groundwater at a site in Maryland. The patented Edible Oil Substrate (EOS®) process is a cost-effective approach for stimulating in situ anaerobic biodegradation with little or no operation and ...
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Case Study: Southern California Water Professionals View Perchlorate Data with EQuIS for ArcGIS
Perchlorate contamination is of major concern in many parts of the country and particularly in the Southwestern United States. In a recent event held at California State University, San Bernardino, perchlorate data from a 2 million record EQuIS data set incorporating the data from over 2000 sample points were examined by environmental professionals from utilities, water districts, several cities, ...
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Edible Oil Barriers for Treatment of Perchlorate Contaminated Groundwater
An EOS® biobarrier was designed and implemented to remediate perchlorate contaminated groundwater. The report describes the site characterization, design steps, implementation, monitoring results and lessons learned from this effective remedial approach. EXECUTIVE SUMMARYThis final technical report documents the demonstration of emulsified edible oils for remediation of perchlorate in ...
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Sorptive removal of Cr (III) ions from aqueous solution onto beach sand
Sorption potential of beach sand for the removal of traces of Cr(III) ions has been investigated. The effects of different electrolytes namely nitric acid, hydrochloric acid and perchloric acid (10−2 to 10−4 M), deionised water, shaking time (5?40 min), amount of sand (50?300 mg/15 cm?) and pH (2?10)on the sorption were studied. The sorption of Cr (III) ions is monitored in its concentration ...
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Effect of carbon nanotube on the thermal decomposition characteristics of selected propellant binders and oxidisers
The effect of carbon nanotube (CNT) on the thermal decomposition behaviour of polymeric binders viz., hydroxyl terminated polybutadiene (HTPB) and glycidyl azide polymer (GAP) as well as oxidisers namely ammonium perchlorate (AP) and phase stabilised ammonium nitrate (PSAN) was investigated using simultaneous TG–DSC. The results indicate that addition of CNT to AP, lowered the thermal ...
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Study of the optimization factors for preparation of heterogeneous reverse osmosis membranes
The influence of the preparation factors such as casting solution composition, different methods of coal modification, evaporation time of solvent and their optimization on performance of cellulose acetate heterogeneous reverse osmosis membranes have been studied. Three types of membranes were made from a blend of cellulose acetate (CA) and coal by weight ratios 1:1.5, 1:1.75 and 1:2. The ...
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