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 Removal of Natural Organic Matter Fractions by Anion Exchange written by Anke Grefte and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Impact of UV Photooxidation on Natural Organic Matter and Its Removal from Drinking Water written by Felicity Roddick and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stantec s Water Treatment written by John C. Crittenden and published by John Wiley & Sons. This book was released on 2022-11-08 with total page 1956 pages. Available in PDF, EPUB and Kindle. Book excerpt: The updated third edition of the definitive guide to water treatment engineering, now with all-new online content Stantec's Water Treatment: Principles and Design provides comprehensive coverage of the principles, theory, and practice of water treatment engineering. Written by world-renowned experts in the field of public water supply, this authoritative volume covers all key aspects of water treatment engineering, including plant design, water chemistry and microbiology, water filtration and disinfection, residuals management, internal corrosion of water conduits, regulatory requirements, and more. The updated third edition of this industry-standard reference includes an entirely new chapter on potable reuse, the recycling of treated wastewater into the water supply using engineered advanced treatment technologies. QR codes embedded throughout the book connect the reader to online resources, including case studies and high-quality photographs and videos of real-world water treatment facilities. This edition provides instructors with access to additional resources via a companion website. Contains in-depth chapters on processes such as coagulation and flocculation, sedimentation, ion exchange, adsorption, and gas transfer Details membrane filtration technologies, advanced oxidation, and potable reuse Addresses ongoing environmental concerns, pharmacological agents in the water supply, and treatment strategies Describes reverse osmosis applications for brackish groundwater, wastewater, and other water sources Includes high-quality images and illustrations, useful appendices, tables of chemical properties and design data, and more than 450 exercises with worked solutions Stantec's Water Treatment: Principles and Design, Updated Third Edition remains an indispensable resource for engineers designing or operating water treatment plants, and is an essential textbook for students of civil, environmental, and water resources engineering.

Download or read book Monitored Natural Attenuation of Inorganic Contaminants in Ground Water written by and published by . This book was released on 2007 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: V.3 ... consists of individual chapters that describe 1) the conceptual background for radionuclides, including tritium, radon, strontium, technetium, uranium, iodine, radium, thorium, cesium, plutonium-americium and 2) data requirements to be met during site characterization.

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 Advanced Oxidation Processes for Water Treatment written by Mihaela I. Stefan and published by IWA Publishing. This book was released on 2017-09-15 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Oxidation Processes (AOPs) rely on the efficient generation of reactive radical species and are increasingly attractive options for water remediation from a wide variety of organic micropollutants of human health and/or environmental concern. Advanced Oxidation Processes for Water Treatment covers the key advanced oxidation processes developed for chemical contaminant destruction in polluted water sources, some of which have been implemented successfully at water treatment plants around the world. The book is structured in two sections; the first part is dedicated to the most relevant AOPs, whereas the topics covered in the second section include the photochemistry of chemical contaminants in the aquatic environment, advanced water treatment for water reuse, implementation of advanced treatment processes for drinking water production at a state-of-the art water treatment plant in Europe, advanced treatment of municipal and industrial wastewater, and green technologies for water remediation. The advanced oxidation processes discussed in the book cover the following aspects: - Process principles including the most recent scientific findings and interpretation. - Classes of compounds suitable to AOP treatment and examples of reaction mechanisms. - Chemical and photochemical degradation kinetics and modelling. - Water quality impact on process performance and practical considerations on process parameter selection criteria. - Process limitations and byproduct formation and strategies to mitigate any potential adverse effects on the treated water quality. - AOP equipment design and economics considerations. - Research studies and outcomes. - Case studies relevant to process implementation to water treatment. - Commercial applications. - Future research needs. Advanced Oxidation Processes for Water Treatment presents the most recent scientific and technological achievements in process understanding and implementation, and addresses to anyone interested in water remediation, including water industry professionals, consulting engineers, regulators, academics, students. Editor: Mihaela I. Stefan - Trojan Technologies - Canada

Download or read book Advanced Oxidation Processes for Water and Wastewater Treatment written by Simon Parsons and published by IWA Publishing. This book was released on 2004-03-01 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The suitability of Advanced Oxidation Processes (AOPs) for pollutant degradation was recognised in the early 1970s and much research and development work has been undertaken to commercialise some of these processes. AOPs have shown great potential in treating pollutants at both low and high concentrations and have found applications as diverse as ground water treatment, municipal wastewater sludge destruction and VOCs control. Advanced Oxidation Processes for Water and Wastewater Treatment is an overview of the advanced oxidation processes currently used or proposed for the remediation of water, wastewater, odours and sludge. The book contains two opening chapters which present introductions to advanced oxidation processes and a background to UV photolysis, seven chapters focusing on individual advanced oxidation processes and, finally, three chapters concentrating on selected applications of advanced oxidation processes. Advanced Oxidation Processes for Water and Wastewater Treatment will be invaluable to readers interested in water and wastewater treatment processes, including professionals and suppliers, as well as students and academics studying in this area. Dr Simon Parsons is a Senior Lecturer in Water Sciences at Cranfield University with ten years' experience of industrial and academic research and development.

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 Membrane Technology in Water Treatment in the Mediterranean Region written by Antonia Lorenzo and published by IWA Publishing. This book was released on 2010-11-24 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: The complex dimensions of the Mediterranean freshwater resources, their fragility and their scarcity have been highlighted and have received considerable attention as a primary priority issue politically, technically and scientifically. Membrane technology, with its different applications in water treatment (desalination, potable water treatment, wastewater treatment and reuse) has showed to be a powerful tool to abate the water crisis in the Mediterranean region. The primary objective of Membrane Technology in Water Treatment in the Mediterranean Region is to support the current research and development activities in membrane technology focused on water treatment in the Mediterranean area, providing an international stage to local research organisations and universities devoted to the development of membrane technologies in the following areas: municipal and industrial wastewater treatment, surface water purification and brackish and sea water treatment for drinking purpose. It covers the identification, mapping and evaluation of the on-going research, in order to propose future research and co-operation strategies. Visit the IWA WaterWiki to read and share material related to this title: http://www.iwawaterwiki.org/xwiki/bin/view/Articles/MembraneTechnologyinWaterTreatmentintheMediterraneanRegion

Download or read book Effect of Natural Organic Matter Metal Ions and Nitrate on Electrochemical Dechlorination of Trichloroethylene written by Noushin Fallahpour and published by . This book was released on 2016 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: Groundwater is susceptible to pollution due to improper waste disposal. Groundwater contamination continues to be a problem in areas where population relies on groundwater as a major source of drinking water. Development of technologies, such as in situ electrochemical transformation to clean contaminated groundwater is of great importance. Electrochemical systems, which mainly consist of two or more arranged electrodes that are immersed in wells in groundwater, are of interest because of their ability to manipulate redox conditions to transform contaminants into non-toxic forms. Aquifers in karst regions are very susceptible to contamination and present a significant exposure routes due to presence of fissures and channels that facilitate contaminant transport under high flow rate. Trichloroethylene (TCE), a toxic chlorinated solvent that causes major health problems, is present in many contaminated aquifers including many that reside in karst regions. Treatment of aquifers contaminated with TCE is difficult in the presence of other contaminants, such as chromate, selenate, and nitrate, which interfere with TCE transformation and degradation mechanisms. Moreover, presence of natural organic matter (NOM) in the groundwater can influence transformation of TCE and other contaminants. Therefore, it is important to evaluate transformation of TCE in the presence of contaminant mixtures in groundwater. In this study, a series of experiments are conducted to (1) evaluate of the effect of co-existing organic and inorganic compounds on the electrochemical dechlorination of trichloroethylene (TCE) in simulated karst media; and (2) assessment of the impacts of high groundwater flow rates in the presence of palladium (Pd) catalyst on TCE transformation rate and the accumulation of precipitates. A small-scale flow-through limestone column is used to simulate a karst aquifer media to evaluate dechlorination of TCE in the presence of organic and inorganic compounds. Iron anode was used to produce ferrous ions and promote reducing conditions in the column. Various current intensities (30, 60, and 90 mA) were applied under the flow rate of 1 mL min−1 and initial TCE concentration of 1 mg L−1. Under the same testing conditions, presence of chromate has the highest influence on TCE removal followed by selenate and then nitrate. The reduction of TCE under 90 mA current, 1 mL min−1 flow rate, and 1 mg L−1 initial TCE concentration, was inhibited in the presence of humic acids due to competition for direct electron transfer and/or reaction with atomic hydrogen produced at the cathode surface by water electrolysis. The use of iron anode creates favorable conditions for TCE reduction but produces aggregates in combination with ferrous ions, which may impact the long-term performance of the remedial system. A vertical acrylic column, with Pd pellets placed on the cathode surface, was used to investigate the impacts of Pd-based catalysis for the removal of TCE under high flow rate (1 L min−1). The effects of electrode materials and current intensities on precipitation, pH and ORP are assessed. The following electrode materials and arrangements were tested: (a) two MMO electrodes as an anode and a cathode, (b) a cast-iron anode and a MMO cathode, and (c) a cast-iron anode and a copper foam cathode. Current intensities of 500, 250, 125, and 62 mA were tested under the flow rate of 1 L min−1 and 5 mg L−1 of initial concentration of TCE. Under the conditions of 1 L min−1 flow, 500 mA current, and 5 mg L−1 initial concentration of TCE, removal efficacy using iron anodes (96%) is significantly higher than that of mixed metal oxide (MMO) anodes (66%) because the iron anode supports reduction conditions by electrolysis. Two types of cathodes (MMO and copper foam) in the presence of Pd/Al2O3 catalyst under various currents (250, 125, and 62 mA) were used to evaluate the effect of cathode materials on TCE removal efficacy. The similar removal efficiencies were achieved for both cathodes, but more precipitation generated with copper foam cathode. Palladium improved TCE degradation by 120% for 250 mA, 100% for 125 mA, 100% for 62 mA, under the conditions of using an iron anode followed by a copper foam cathode with 1 L min−1 flow rate. The high velocities of groundwater flow can have important implications since the groundwater flow rate can significantly fluctuate, especially in karst aquifers. The optimization of the electrochemical systems for successful operation under high flow rates allows the robustness and great flexibility for the application. It is assumed that the high flow rate would favor the transformation of contaminants since it would flush out precipitates and prevent clogging.

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 Effects of Chemical Treatment for Organic Matter Removal on Mineral Soil Constituents written by Adelina Siregar and published by . This book was released on 2004 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bioavailability of Contaminants in Soils and Sediments written by National Research Council and published by National Academies Press. This book was released on 2003-05-03 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bioavailability refers to the extent to which humans and ecological receptors are exposed to contaminants in soil or sediment. The concept of bioavailability has recently piqued the interest of the hazardous waste industry as an important consideration in deciding how much waste to clean up. The rationale is that if contaminants in soil and sediment are not bioavailable, then more contaminant mass can be left in place without creating additional risk. A new NRC report notes that the potential for the consideration of bioavailability to influence decision-making is greatest where certain chemical, environmental, and regulatory factors align. The current use of bioavailability in risk assessment and hazardous waste cleanup regulations is demystified, and acceptable tools and models for bioavailability assessment are discussed and ranked according to seven criteria. Finally, the intimate link between bioavailability and bioremediation is explored. The report concludes with suggestions for moving bioavailability forward in the regulatory arena for both soil and sediment cleanup.

Download or read book Removal of Natural Organic Matter from Drinking Water by Ion Exchange written by Kathryn Linge and published by . This book was released on 1997 with total page 48 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 Advanced Reduction Processes a New Class of Treatment Processes written by Bhanu Prakash Vellanki and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A new class of treatment processes called Advanced Reduction Processes (ARP) has been proposed. The ARPs combine activation methods and reducing agents to form highly reactive reducing radicals that degrade oxidized contaminants. Batch screening experiments were conducted to identify effective ARP by applying several combinations of activation methods (ultraviolet light, ultrasound, electron beam, microwaves) and reducing agents (dithionite, sulfite, ferrous iron, sulfide) to degradation of five target contaminants (perchlorate, nitrate, perfluorooctanoic acid, 2,4 dichlorophenol, 1,2 dichloroethane) at 3 pH levels (2.4, 7.0, 11.2). These experiments identified the combination of sulfite activated by ultraviolet light produced by a low pressure mercury vapor lamp as an effective ARP. More detailed kinetic experiments were conducted with nitrate and perchlorate as target compounds and nitrate was found to degrade more rapidly than perchlorate. The effects of pH, sulfite concentration, and light intensity on perchlorate and nitrate degradation were investigated. The effectiveness of the sulfite/UV-L treatment process improved with increasing pH for both perchlorate and nitrate.