Download or read book Biological and Ion Exchange Nitrate Removal Evaluation written by Kerry J. Meyer and published by . This book was released on 2010-10-22 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrate Contamination written by Istvan Bogardi and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nitrate content of drinking water is rising at an alarming rate in several regions of NATO countries and elsewhere in the world. The increase is due to lack of proper sewage treatment, and primarily to excess fertilizer application. Also, eutrophication in several coastal areas is triggered by high nitrate concentrations. The main purpose of this book is to integrate scientific knowledge related to exposure assessment, health consequences and control of nitrate contamination in water. The motivation is related to the magnitude, the possible adverse health effects, and the high cost of control ling nitrate contamination. Future research tasks are defined by an interaction among hydro logists, toxicologists and environmental engineers in an integrated framework for nitrate risk management. The target readership of this book is a mix of university colleagues, practitioners from both the private and public sectors and advanced graduate students working with the hydrological, health science or environmental engineering aspects of nitrate contamination. The main conclusions include: 1. For risk assessment purposes, knowledge and sufficiently accurate models are available to predict nitrate load and its fate in water under changes in land use. 2. Once agricultural exposure controls are implemented, the response times in ground water may be so long as to make controls unrealistic. 3. It is still unknown whether agricultural best management practice is a compromise between nitrate risk reduction and agricultural revenue. 4. The current drinking water guidelines of 10 mg/L NOrN need not be changed.
Download or read book Nitrate Removal Evaluation of Amberlite IRA 904 Ion Exchange Resion written by Des Moines (Iowa). Water Works Laboratory and published by . This book was released on 1989 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrate Removal from Water Supplies by Ion Exchange written by Dennis A. Clifford and published by . This book was released on 1978 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrate Removal from Water Supplies by Ion Exchange written by Dennis A. Clifford and published by . This book was released on 1977 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combined Ion Exchange biological Denitrification for Nitrate Removal from Ground Water written by J. P. van der Hoek and published by . This book was released on 1988* with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrates in Groundwater written by Larry W. Canter and published by Routledge. This book was released on 2019-01-22 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: This time-saving book provides extensive coverage of all important aspects of nitrates in groundwater, ranging from prevention to problem assessment to remediation. It begins by highlighting the nitrogen cycle and related health concerns, providing both background information and a unique perspective on health issues. It then analyzes subsurface pr
Download or read book Nitrates in Groundwater written by Larry W. Canter and published by Routledge. This book was released on 2019-01-22 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: This time-saving book provides extensive coverage of all important aspects of nitrates in groundwater, ranging from prevention to problem assessment to remediation. It begins by highlighting the nitrogen cycle and related health concerns, providing both background information and a unique perspective on health issues. It then analyzes subsurface pr
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 Groundwater Quality written by Harriet Nash and published by Springer. This book was released on 1994-10-31 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Groundwater quality monitoring and testing is of paramount importance both in the developed and developing world. This book presents a series of papers illustrating the varied nature of current research into groundwater quality. Urban and rural supplies are covered through a case history approach, and the importance of remedial action to prevent deterioration is emphasized.
Download or read book Nitrate Removal for Small Public Water Systems written by and published by . This book was released on 1983 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biological Removal of Nitrate from River Water written by R. B. Gauntlett and published by . This book was released on 1979 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Membrane Biofilm Reactor Process for Nitrate and Perchlorate Removal written by S. Adham and published by IWA Publishing. This book was released on 2005-04-30 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this project were to evaluate the performance of an innovative hydrogen-fed membrane biofilm reactor (MBfR) for nitrate and perchlorate removal, and identify the system operational and design parameters that affect the biological reduction process. The MBfR contained hollow-fiber membranes within a cylindrical module. Hydrogen was fed to the fibers filling the inside and passively diffusing through the membrane avoiding the formation of a hydrogen atmosphere and serving as an electron donor for the biofilm growing on the outside of the hollow fibers. The biofilm within the reactor was developed from the indigenous bacteria present in the groundwater and was not artificially inoculated or amended. Following the MBfR, an aeration process was employed to oxygenate the water in preparation for its introduction into a distribution system as a drinking water source. A subsequent media filter captured any sloughed biomass and provided a support for aerobic organisms to remove any residual dissolved hydrogen. Process Demonstration The MBfR process was demonstrated at pilot-scale to reduce perchlorate contaminated groundwater (55 ?g/L) to below the current 4 ?g/L California Department of Health Services (CaDHS) perchlorate action limit. The simultaneous removal of influent dissolved oxygen and nitrate to below detection limits was also observed. Their removal has been observed with the MBfR system operated at system flow rates corresponding to theoretical hydraulic residence times between 15 and 60 minutes. In addition, measured hydrogen consumption closely matches theoretical calculations based on stoichiometry and anaerobic biomass development. Microbial Ecology Bench-scale investigations into the microbial ecology of the mixed cultures in MBfRs revealed that perchlorate reducing bacteria (PCRB) were found to be present in a denitrifying system that had not been previously exposed to perchlorate. However, a dominant PCRB species increased from 14 to 21 percent of total bacteria when 100-?g/L perchlorate was added to the influent. Increasing perchlorate reduction led to further increases in the dominant PCBR and the perchlorate-removal capacity of MBfRs. Another important finding is that oxygen alone can serve as a primary acceptor for perchlorate reduction, and that the oxygen reduction appeared to be more favorable for perchlorate reduction than was nitrate reduction. Ultimately, full-scale application MBfR technology could effectively and economically be used to replace costly treatment technologies currently used by municipalities to treat perchlorate-contaminated drinking water sources. This research defined the critical parameters and operating conditions required for full-scale application and provided an extensive review of the critical water quality issues considered for drinking water by CaDHS and other state primacy agencies. In addition, this project has direct relevance to the application of biological treatment for the removal of nitrate (or other biologically reducible compounds) from contaminated groundwater. For a long time, biological denitrification has long been used in wastewater treatment, but not in drinking water treatment. Due to concerns about operating a biological process in a water treatment plant, nitrate removal in the United States has been largely limited to ion-exchange or membranes, both of which are expensive processes and can generate difficult to handle residuals. The results obtained in this study looked at simultaneous biological perchlorate removal and denitrification. Originally published by AwwaRF for its subscribers in 2004. This publication can be purchased and downloaded via Pay Per View on Water Intelligence Online - click on the Pay Per View icon below
Download or read book Removal of nitrate from contaminated water supplies for public use written by Gerald A. Guter and published by . This book was released on 1982 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessing Innovative Technologies for Nitrate Removal from Drinking Water written by Shoeleh Shams and published by . This book was released on 2010 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several health problems may be caused by excess nitrate in drinking water, the most important of which being methemoglobinemia, a potentially fatal disorder, in infants under six months of age. Many different parts of the world have been facing the problem of nitrate contaminated surface and groundwaters due in large part to excessive use of nitrate-based chemical fertilizers. In the Region of Waterloo, Ontario, Canada some groundwater sources have nitrate concentrations approaching the Health Canada and Ontario Ministry of the Environment maximum acceptable concentration (MAC) of 10 mg NO3--N/L. Finding a practical and economical way to reduce nitrate concentrations in representative groundwater in the Region of Waterloo was the overall objective of this research. To achieve this goal, nitrate removal technologies including biological denitrification, ion exchange (IX), reverse osmosis (RO), electrodialysis (ED), and chemical denitrification were reviewed and compared. IX and RO were found to be the most promising technologies for nitrate removal. They have also been approved by the United States Environmental Protection Agency (USEPA) as Best Available Technologies (BAT). To investigate the feasibility of IX and RO for nitrate removal from representative groundwater in the Region of Waterloo, bench-scale experiments were conducted and compared. These technologies could be considered for application at full- or point-of-use (POU)-scale. Decision support assistance for the selection of the appropriate technology for different technical and economical conditions is provided as an outcome of this work. Two nitrate-selective ion exchange resins (Dowex NSR-1 and Purolite® A-520E), two non-selective resins (Purolite® A-300E and Amberlite® IRA400 Cl), and a commercially-available RO POU device (Culligan® Aqua-Cleer® model RO30), which included a particle filter and a carbon block, were tested with deionized water and real groundwater.* IX results confirmed that production time before resin exhaustion was influenced by operating conditions, specifically bed depth as would be expected. It was also confirmed that the presence of competing anions (sulfate, chloride) and alkalinity adversely affected performance, with sulfate being the main competitor for nitrate removal. The extent of these effects was quantified for the conditions tested. At the end of the runs, the non-selective resins were prone to potential nitrate displacement and release into product water and are therefore not recommended. The nitrate-selective resins did not release previously adsorbed nitrate as their capacity became exhausted. Purolite® A-520E was identified as the best alternative amongst the four resins for removing nitrate from the representative groundwater source. The RO unit removed roughly 80% of the nitrate from groundwater. Background ions didn't appear to compete with each other for removal by RO units, so RO might be a more appropriate technology than IX for nitrate removal from waters with high concentrations of sulfate or TDS. Since RO removes other background ions as well as nitrate, the product water of RO is low in alkalinity and can potentially be corrosive, if water from a small full-scale system is pumped through a communal distribution system. Post-treatment including pH adjustment, addition of caustic soda, and/or corrosion inhibitors may be required. While the carbon block did not play a substantial role with respect to removal of nitrate in the groundwater tested, a potential issue was identified when running RO systems without the carbon block. In deionized water (and presumably in very low alkalinity real waters) it was noted that RO nitrate removal efficiency dropped substantially as the alkalinity of the influent water approached zero. With respect to the scale of application of IX and RO devices, IX can be applied at full-scale without requiring large amounts of space. However, if feed water contains high concentrations of sulfate or TDS, nitrate leakage happens sooner and regeneration would be needed at more frequent intervals. Also, chloride concentrations in IX product water might exceed aesthetic objectives (AO) and should be monitored in cases of high feed water TDS. POU IX devices are not recommended when feed water nitrate concentration is high due to potential nitrate leakage into the product water when the resin is nearing exhaustion which increases public health risk. Issues associated with RO application at full-scale are high energy demand, low recovery, high costs, need of pre-treatment (fouling control), and post-treatment (corrosion control). On the other hand, POU RO devices may be acceptable since low recovery is of less importance in a household system, and product water corrosivity is less relevant. POU RO devices are preferable to POU IX units due to their lower risk of nitrate leakage into treated water. * Mention of trade names or commercial products does not constitute endorsement or recommendation for use.
Download or read book Ammonia Removal from Waste Waters written by and published by . This book was released on 1976 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrate Removal from Ground Water by Ion Exchange written by Robert Simon Reich and published by . This book was released on 1976 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:
