Download or read book Removal and Destruction of Perchlorate by Activated Carbon based Processes written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Perchlorate written by Baohua Gu and published by Springer Science & Business Media. This book was released on 2006-07-02 with total page 413 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a detailed description of perchlorate chemistry and recent advances in innovative remediation technologies for perchlorate contamination and their pros and cons Additionally, the first book to describe the natural occurrence of perchlorate and its unique isotopic signatures for environmental forensics and its detection in the environment, particularly the real-time analysis using surface enhanced Raman spectroscopy
Download or read book Perchlorate Ion C104 Removal Using an Electrochemically Induced Catalytic Reaction on Modified Activated Carbon written by Meredith Caitlyn Langille and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Perchlorate is known to adversely affect the thyroid gland functions including iodide take up, thus perchlorate should be removed from drinking water. Bituminous coal-based activated carbon (AC) has been used for perchlorate removal in past years. Virgin carbon and carbon modified by oxidation with HNO3, NaOH and H2O2 were examined in this study for their ability to remove perchlorate by reduction or adsorption mechanisms. Surface functional groups formed on the modified AC (MAC) were examined with diffuse reflectance infrared spectrometry. Inhibition of perchlorate removal onto MAC by various anions ( - Cl, - 3 NO, and - 2 4 SO) and solution pH (4.5, 7.2 and 10.5) were examined to characterize the MACs before an electrochemical reaction was performed. Surface functional groups were increased by oxidation. Groups that were found on the carbon include, but are not limited to lactone, quinine, carboxylate, and nitrogenoxygen groups. The effect of pH on removal of perchlorate by MAC was greatly affected by the change in the zero point charge (ZPC) induced on the carbon by modification. Virgin carbon also experienced difficulty in removing perchlorate when solution pH was above the ZPC. Anion inhibition varied with the modification process. - 3 NO inhibited perchlorate removal only by the virgin carbon. The other anions showed no major effects on the removal efficiency of perchlorate by the carbons. Electrochemical processes did not show favorable results in removal of perchlorate. The dominant mechanism of perchlorate removal during desorption tests was adsorption onto the carbon surfaces via ion exchange.
Download or read book Treatability of Perchlorate in Groundwater Using Ion Exchange Technology Phase II written by L. Aldridge and published by IWA Publishing (International Water Assoc). This book was released on 2005-04-30 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since 1997, several perchlorate treatment technologies have proven to be technically feasible at drinking-water treatment scale: biological reduction, ion exchange, reverse osmosis (RO) membranes, and granular activated carbon (GAC). The objectives of this project were to demonstrate the long-term performance of conventional ion-exchange technology for perchlorate removal and evaluate three disparate alternatives (chemical, biological, electrolytic) for brine treatment and reuse. This project evaluated three fundamentally different brine treatment and reuse processes. The first process, the biological brine treatment system, operated as a sequencing batch reactor (SBR). Spent 3 percent (0.5 N NaCl) brine was introduced to the nitrate and perchlorate degrading culture in the reactor and acetic acid was supplied to this culture as an electron donor for the reduction process. Once the nitrate and perchlorate were biodegraded, the mixture was settled, filtered, and amended with chloride before its reuse as regenerant solution. The second process, the physical/chemical brine treatment system, employed a high-pressure and high-temperature catalytic process to reduce the nitrate and perchlorate in the spent brine. After the process, the treated brine was ready for reuse without subsequent treatment. The system used a stoichiometric dose of a chemical reductant (ammonia) based on the measured concentrations of nitrate and perchlorate in the spent brine. The last process, a simple bipolar electrochemical cell, electrolytically reduced the perchlorate and/or nitrate present in the spent ion exchange brine. Once reduced, the brine could be immediately reused. This process did not require the addition of an electron donor as with the biological process, or a reductant as with the physical/chemical treatment process.
Download or read book Removal of Bromate and Perchlorate in Conventional Ozone GAC Systems written by Mary Jo Kirisits and published by American Water Works Association. This book was released on 2001 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Removal of Perchlorate by Sorption and Biological Reduction in an Activated Carbon Filter written by Jess Carl Brown and published by . This book was released on 1999 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Treatability of Perchlorate Containing Water by RO NF and UF Membranes written by Gary Amy and published by IWA Publishing. This book was released on 2004-01-01 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: The California Department of Health Services has established a provisional action level of 4 ug/L for perchlorate in drinking water due to its toxicity. There are 14 states in the United States that have thus far confirmed perchlorate in ground or surface waters. Ongoing research is investigating other treatment technologies for perchlorate rejection, including biological degradation, ion exchange, and activated carbon. The major objectives of this project were to: determine the removal/rejection of perchlorate (ClO4-) ion by high pressure membranes, including reverse osmosis (RO), nanofiltration (NF), and tight ultrafiltration (UF); evaluate the effects of water quality parameters, pH, ionic strength (conductivity), and co-ions and counter-ions, on process performance; and study membrane operating conditions (e.g., recovery) on perchlorate rejection and potential scaling. Water quality is a determining factor in applying high pressure membranes to perchlorate rejection. Effective rejection of perchlorate by RO, NF, and tight UF has been demonstrated according to two rejection mechanisms: steric (size) versus electrostatic (charge) exclusion. Based on its size (hydrodynamic radius), perchlorate is selectively rejected over chloride through size exclusion; however, based on charge exclusion, sulfate is selectively rejected over perchlorate. Originally published by AwwaRF for its subscribers in 2003. This publication can also be purchased and downloaded via Pay Per View on Water Intelligence Online
Download or read book Impacts of Natural Organic Matter on Perchlorate Removal by an Advanced Reduction Process written by Yuhang Duan and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Perchlorate is one of the major emerging contaminants of concern and has been found in soil and water systems throughout the United States. Human exposures to perchlorate could occur by ingestion of contaminated water and food as well as by skin contact. Studies show that perchlorate blocks the sodium iodide symporter (NIS) protein in human body, which results in several diseases. It has been demonstrated that perchlorate can be removed by Advanced Reduction Processes (ARPs) that combine chemical reductants (e.g. sulfite) with activating methods (e.g. UV light) in order to produce highly reactive reducing free radicals that are capable of rapid and effective perchlorate reduction. However, other compounds in a real system might inhibit or promote this reduction process. Natural organic matter (NOM) widely exists in the environment and it can absorb UV light, so it has the potential to influence the process of perchlorate reduction by ARPs that use UV light as the activating method. Therefore, batch experiments were conducted to obtain data on the impacts of natural organic matter and light intensity on destruction of perchlorate by the ARPs that use sulfite activated by ultraviolet light produced by low-pressure mercury lamps or KrCl excimer lamps. The results indicate that NOM strongly inhibits perchlorate removal by either the sulfite/UV-KrCl or the sulfite/UV-L ARP, because NOM competes with sulfite for UV light and can possibly scavenge sulfite radicals. Even though the absorbance of sulfite is much higher at UV wavelength of 222 nm than that at 254 nm, the results indicate that a higher portion of perchlorate was removed with the UV-L lamp than with the UV-KrCl lamp. The results of this study will help to develop the proper way to apply the ARPs in a real wastewater treatment plant.
Download or read book Perchlorate in the Environment written by Edward Todd Urbansky and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on a symposium sponsored by the Environmental Division of the American Chemical Society, Perchlorate in the Environment is the first comprehensive book to address perchlorate as a potable water contaminant. The two main topics are: analytical chemistry (focusing on ion chromatography and electrospray ionization mass spectrometry), and treatment or remediation. Also included are topics such as ion exchange, phytoremediation, bacterial reduction of perchlorate, bioreactors, and in situ bioremediation. To provide complete coverage, background chapters on fundamental chemistry, toxicology, and reulatory issues are also included. The authors are environmental consultants, government researchers, industry experts, and university professors from a wide array of disciplines.
Download or read book Tailoring and Regeneration of Granular Activated Carbon for Perchlorate Removal written by Weifang Chen and published by . This book was released on 2005 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perchlorate contaminates waters in 15 US states that 15 million American could otherwise drink. Although, conventional granular activated carbon (GAC) has a very limited capacity for removing perchlorate, it was found that ammonia thermal tailoring could enhance its bed life.
Download or read book Abiotic and Biotic Perchlorate Removal in an Activated Carbon Filter written by Jess Carl Brown and published by . This book was released on 2002 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Perchlorate written by Kathleen Sellers and published by CRC Press. This book was released on 2006-08-30 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of analytical methods for identifying widespread perchlorate contamination brought about an explosion of research into the environmental problems and their potential solutions along with a corresponding increase in the availability of information. Unlike reference works that focus on only a few aspects of this contaminant, Perchlora
Download or read book Perchlorate Removal Destruction and Field Monitoring Demonstration written by and published by . This book was released on 2007 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this demonstration were to evaluate and demonstrate a complete perchlorate ion exchange process for groundwater that included a unique, regenerable, perchlorate-selective ion exchange resin; an efficient regeneration technique that greatly minimized waste volume; methods for treating regeneration waste from this process that would reduce cost by enabling discharge or reuse; and to demonstrate a new perchlorate field monitor with ppb detection. In order to validate the performance and economics of the proposed processes compared to current perchlorate treatment processes, the following objectives were proposed: 1. Demonstrate perchlorate removal in groundwater from>50 ppb to
Download or read book Removal of Perchlorate in Ammunition Wastewater by Zero valent Iron and Perchlorate Respiring Bacteria written by Se Chang Ahn and published by ProQuest. This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Perchlorate has recently received a great deal of attention due to high concentrations found in groundwaters and surface waters. The US Army and DoD facilities generate ammunition wastewater containing perchlorate (ClO 4 - ), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and 2,4-dinitroanisole (DNAN) (i.e. PAX-21 wastewater) from munitions manufacturing and demilitarization processes. Perchlorate is known to affect human health by interfering with the uptake of iodide into the thyroid glands. The US EPA recently set the perchlorate reference dose to 0.0007 mg/kg/day which corresponds to a drinking water equivalent level of 24.5 ppb. Aqueous perchlorate is both chemically stable in natural water and extremely soluble and mobile; as a result, many traditional wastewater treatment techniques that are commonly used for solvents and other organic pollutants are not effective for removal of perchlorate from contaminated water. Presently, most Army ammunition plants use granular activated carbon (GAC) adsorption and alkaline hydrolysis to separate and treat energetic compounds in wastewater from munitions manufacturing and demilitarization processes. GAC processes are not only expensive but generate explosive-laden spent carbon, which needs to be treated or disposed of properly to avoid secondary contamination problems. This additional treatment further increases the overall cost of wastewater treatment. The overall objective of this research was to develop a novel treatment process for the removal of perchlorate and energetic compounds from mixed ammunition wastewater. We investigated two options for effective removal of perchlorate from mixed munitions wastewater that contains both perchlorate and energetic compounds: (1) increasing the solution temperature to overcome the kinetic barrier of perchlorate reduction by zero-valent iron; and (2) integrating Fe(0)-biological process for simultaneous removal of perchlorate and energetic compounds. Perchlorate reduction by zero-valent iron at elevated temperatures was investigated with a continuous-flow system that consisted of an iron-packed pressure vessel and a heat exchanger. Results from the continuous-flow system showed that 99% of perchlorate was removed in 1 hour of contact time at 175°C. With decreasing pH to 2.5, more than 60% of perchlorate was removed with an iron contact time of 30 min at operation temperature of 95°C. Increasing the reactor temperature to 125°C resulted in 98% perchlorate removal at the same retention time of 30 min. This result demonstrated that Fe(0) technology combined with heating may be a viable option for the removal of perchlorate from Army ammunition wastewater. Biodegradation experiments using glucose as the primary sources of electrons and carbon were conducted to evaluate microbial perchlorate reduction as a practical option for the treatment of perchlorate in PAX-21 wastewater. The results indicated that the constituents in PAX-21 wastewater may be toxic to perchlorate reducing bacteria. A series of batch toxicity test was conducted to identify the toxic constituents in PAX-21 wastewater and DNAN was identified as the primary toxicant responsible for inhibiting the activity of perchlorate reducing bacteria. It was hypothesized that pretreatment of PAX-21 by zero-valent iron granules will transform toxic constituents in PAX-21 wastewater to non-toxic products. Zero-valent iron pretreatment completely removed DNAN and RDX. After a 3-day acclimation period, perchlorate in iron-treated PAX-21 wastewater was rapidly decreased to an undetectable level in 2 days, which demonstrated that iron treatment not only removed energetic compounds but also eliminated the toxic constituents that inhibited the subsequent microbial process. Finally, potential application of energetic compounds as the source of electrons for perchlorate reduction by PRB was investigated. It was hypothesized that the pretreatment of PAX-21 wastewater with Fe(0) would convert energetic compounds to products that are more amenable for biological oxidation and that these products can also serve as electron donors for PRB. Results of batch experiments showed that DNAN was completely reduced to 2,4-diaminoanisole (DAAN) and RDX was completely reduced to formaldehyde in the presence of cast iron granules within 2 h. Batch biodegradation experiments showed that formaldehyde can serve as an electron donor for perchlorate respiring bacteria. It was also demonstrated that complete reduction of perchlorate in iron-treated PAX-21 wastewater can be achieved without adding an exogenous electron donor. This study confirmed that iron pretreatment not only removed energetic compounds, but also transformed the energetic compounds to products that can serve as the source of electrons for perchlorate respiring bacteria. Based on the results, we proposed an integrated Fe(0)-biological process for simultaneous removal of perchlorate and energetic compounds, which consists of (1) a Fe(0) process for the reduction of electron-withdrawing nitro groups to biodegradable compounds and (2) an anaerobic biological treatment process containing perchlorate-respiring bacteria, which utilize Fe(0)-treated energetic compounds as electron donor and perchlorate as electron acceptor.
Download or read book Preparation and Characterization of N alkyl Quaternized Activated Carbon for Perchlorate Removal from Groundwater written by Xin Gu and published by . This book was released on 2011 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Tailored Granular Activated Carbon to Remove Perchlorate in the Presence of Oxyanions written by Judodine Patterson and published by . This book was released on 2009 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Perchlorate in Drinking Water written by and published by . This book was released on 2004 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
