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A listing of webinars, symposia, and conferences relevant to this work.
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The International Water Conference
November 6-10 | San Antonio, Texas
IWC brings together plant personnel, engineers, water chemists and biologists, business development managers, administrators, operation managers, and engineering managers to discuss new applications in water treatment.
Water Quality Technology Conference & Exposition
November 13-17 | Indianapolis, Indiana
This AWWA conference provides a practical forum for a wide range of water technology professionals to exchange the latest research and information.
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Project Update from the WINSSS Center
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The Water Innovation Network for Sustainable Small Systems (WINSSS) Center at the University of Massachusetts-Amherst is led by Dr. David Reckhow.
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The WINSSS Center brings together a national team of experts to transform drinking water treatment for small water systems to meet the urgent need for state-of-the-art innovation, development, demonstration, and implementation of treatment, information, and process technologies in part by leveraging existing relationships with industry.
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Biological Management of Nitrogenous Chemicals in Small Systems: Ammonia, Nitrite, Nitrate, and N-Disinfection By-Products
Mary Jo Kirisits, Gerald E. Speitel, Kerry Kinney, Michal Ziv-El, Emily Palmer, University of Texas
David A. Reckhow, Chul Park, Soon-Mi Kim, University of Massachusetts
Jess Brown, Carollo Engineers
Nitrogen (N) is present in drinking water in a variety of forms including ammonia (NH3), nitrite (NO2-), nitrate (NO3-), dissolved organic nitrogen (DON), and nitrogenous disinfection by-products (N-DBPs). Biological treatment processes provide an attractive treatment option for small water systems (SWS) because they can be automated and might be the lowest cost treatment option for certain contaminants. Development of a robust biological treatment system for nitrogenous contaminants will provide SWS with an economical method to meet current and future regulations associated with nitrogen. The objective of this project is to biologically manage the nitrogenous contaminant grouping (ammonia, nitrite, nitrate, and N-DBP precursors) in SWS via nitrification and denitrification and to demonstrate that these processes can yield other water quality benefits related to trace organic compound (TrOC) removal.
Currently, we are examining the impact of nitrification on TrOC degradation. Four down-flow biofilter trains (each with two biofilters in series, as shown in Figure 1) were designed. Each biofilter is packed with granular activated carbon to achieve an empty bed contact time (EBCT) of 3 minutes, simulating a full-scale EBCT of 10 minutes according to the biofilter-scaling model of Manem and Rittmann (1990). Two biofilter trains are operated with natural organic matter from surface water, and two are operated with natural organic matter from groundwater. For both surface water and groundwater, one train is nitrifying and one is non-nitrifying (called the ‘standard aerobic’ biofilter). All trains contain a suite of 10 TrOCs in the influent, including estrone, thiabendazole, 2-methylisoborneol (2-MIB), naproxen, caffeine, diclofenac, geosmin, atenolol, N,N-diethyl-meta-toluamide (DEET), and gemfibrozil; these TrOCs represent pharmaceuticals, personal care products, and taste and odor compounds.
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Figure 1. Bench-scale biofilter train. Each biofilter train consists of two biofilters in series, where each biofilter has a 3-min EBCT.
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Figure 2. Removal of (a) ammonia in the 3-min bench-scale nitrifying biofilters and (b) 2-MIB in the 3-min bench-scale biofilters. Biofilters are operated with surface water (SW) or groundwater (GW) natural organic matter. Nitrifying biofilters contain 1 mg/L NH3-N in the influent.
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Once the final operating conditions had been implemented (day 60), stable nitrification (generally greater than 95 percent ammonia removal) was achieved in the 3-min biofilters (Figure 2a). The nitrifying biofilters (both those supplied with surface water and those supplied with groundwater natural organic matter) achieved 100% 2-MIB removal more quickly than did their standard aerobic (non-nitrifying) counterparts (Figure 2b). It is possible that the production of soluble microbial products (SMP) by nitrifiers spurred the growth of heterotrophic microorganisms capable of 2-MIB degradation. We are currently analyzing the concentrations of the other TrOCs to determine if the occurrence of nitrification has a similar benefit to their removal in the biofilters.
Preliminary data suggest that the occurrence of nitrification, as compared to the absence of nitrification, in the bench-scale biofilters does not have substantial impact on the formation of dihaloacetic acids, trihaloacetic acids, and trihalomethanes following disinfection. In the coming year, the impact of nitrification on the formation of N-DBPs will be assessed.
References
Manem, J.A. and B.E. Rittmann. 1990. “Scaling Procedure for Biofilm Processes.” Water Sci Technol. 22:1/2:329-346.
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Project Update from the DeRISK Center
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The Design of Risk-reducing, Innovative-implementable Small-system Knowledge (DeRISK) Center at the University of Colorado-Boulder is led by Dr. Scott Summers.
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The DeRISK Center’s overall objectives focus on applying principles of risk reduction, sustainability and new implementation approaches to innovative technologies that will reduce the risk associated with key contaminant groups and increase the chance of adoption and sustainable use in small systems.
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In-Line Diffused Aeration to Reduce THMs in Distribution Piping
M.R. Collins, University of New Hampshire
Several methods exist for controlling THM formation, including reducing natural organic matter (NOM) prior to chlorine disinfection, and using an alternate disinfectant such as ozone, chloramines, or UV. Using these disinfectants will prevent or reduce the formation of THMs, but could facilitate the production of other potentially harmful byproducts. Also, using ozone or UV as a disinfectant will not provide a residual in the distribution system (USEPA, 1981 & USEPA, 1999). While effective at reducing THM formation, changing or upgrading the water treatment plant to include these control techniques could be costly and negatively affect other plant processes.
Posttreatment aeration is another strategy to control THMs, and involves removing the THMs after formation. Countercurrent packed towers, diffused aeration in open reactors, and spray aeration in storage tanks are all viable aeration methods to remove THMs (USEPA, 1981 and Brooke & Collins, 2011). While the above methods are viable and have been applied in the field, all require depressurization of the water, and are limited in terms of placement in the water distribution system. Placement in the distribution system is important since THMs continue to form in the system, and often exceed regulations when at the far end of the system. This research explores both vertical in-line diffused aeration (VILDA) and horizontal in-line diffused aeration (HILDA) to reduce THMs, which has the potential to be cost effective and conveniently placed where needed in the distribution system.
A schematic of an in-line diffused aeration system is depicted in Figure 1. The basic components consist of an air compressor, air-water reactor, air injector, air release system and associated air and water flow meters. The basic difference between VILDA and HILDA systems is the configuration of the air-water reactor. The VILDA system will utilize a countercurrent arrangement where air is injected in the bottom of the vertical reactor while the water enters at the top of the reactor. The HILDA will have air and water flowing concurrently through the horizontal reactor.
Continue reading on WaterOperator.org.
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Figure 1. Schematic of basic in-line diffused aeration system.
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Comprehensive Manual for a Sweeping Gas Membrane Distillation Prototype and Design of a Field Scale Solar Nanofiltration Membrane Desalination Facility
Serwon, D. (2016). Comprehensive manual for a sweeping gas membrane distillation prototype and design of a field scale solar nanofiltration membrane desalination facility. Available at hdl.handle.net/10150/613597.
Why it's interesting: This University of Arizona master's thesis discusses the development and piloting of prototype water purification units utilizing membrane distillation and nanofiltration membrane technology to improve access to potable water on the Navajo Nation. The report also includes comprehensive manuals that will be shared with the Navajo Department of Water Resources designed to enable the practical application of these innovative technologies.
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Understanding Small Water System Violations and Deficiencies
Oxenford, J.L. and Barrett, J.M. (2016). Understanding small water system violations and deficiencies. Journal of the American Water Works Association, 108:3, 31-37. doi:0.5942/jawwa.2016.108.0040
Why it's interesting: This study investigated why small water systems were failing to comply with drinking water regulations.
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Oxidation of Manganese(II) with Ferrate: Stoichiometry, Kinetics, Products and Impact of Organic Carbon
Goodwill, J.E. Mai, X., Jiang, Y. Reckhow, D.A., Tobiason, J.E. (2016) Oxidation of manganese(II) with ferrate: Stoichiometry, kinetics, products and impact of organic carbon. Chemosphere, 159, 457-464. doi:10.1016/j.chemosphere.2016.06.014.
Why it's interesting: The results of this study indicate ferrate is a viable alternative to other strong oxidants used for Mn(II) oxidation in drinking water treatment and may be a preferable option for utilities treating water containing problematic levels of Mn(II) in addition to NOM.
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How Ozone and Biofiltration an Contribute to Potable Reuse
Two California projects are paving the way for demonstrating the effectiveness of ozone-enhanced biofiltration as a key treatment process in potable reuse facilities.
40 Years After Legionnaires Outbreak, the Case for a 'Safe Breathing Water Act'
In this commentary, a Drexel University professor proposes amending the Safe Drinking Water Act to include provisions for reducing the risk of inhaling Legionella, Mycrobacteria and other respiratory pathogens amplified in water systems.
New Study Shows High Potential for Groundwater to be Corrosive in Half of U.S. States
A U.S. Geological Survey assessment of more than 20,000 wells nationwide shows that untreated groundwater in 25 states has a high prevalence of being potentially corrosive.
H2O Innovation Has Won A Water/Wastewater Prize At The 2016 National Awards Of Merit By The DBIA
The prize was for a state-of-the-art ultrafiltration water purification system in Clifton, Colorado.
Water Research Foundation and National Science Foundation Partner to Fund Lead Corrosion Study
WRF and NSF hope the research will provide new insights into the efficient application of phosphate to control dissolved and total lead concentrations.
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The two National Centers for Innovation in Small Drinking Water Systems, based at the University of Colorado - Boulder and the University of Massachusetts - Amherst, are collaborative research groups charged with examining and reducing the barriers of innovative treatment technology implementation at small drinking water systems. The funding for the centers comes from the U.S. Environmental Protection Agency as part of its Science to Achieve Results (STAR) program.
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