Grantee Research Project Results
Final Report: Design of Risk-reducing, Innovative-Implementable Small-System Knowledge(DeRISK) Center
EPA Grant Number: R835603Center: Design of Risk-reducing, Innovative-Implementable Small-System Knowledge Center
Center Director: Summers, R. Scott
Title: Design of Risk-reducing, Innovative-Implementable Small-System Knowledge(DeRISK) Center
Investigators: Summers, R. Scott , Westerhoff, Paul , Linden, Karl G. , Uber, Jim , Cook, Sherri , Hristovski, Kiril D , Dotson, Aaron , Collins, M. Robin , Malley, James P. , Barrett, Joy , Hogrewe, William , Seidel, Chad , Rosario-Ortiz, Fernando , Rodriquez, Roberto
Institution: Arizona State University , University of Alaska - Anchorage , University of Colorado at Boulder , University of New Hampshire , Rural Community Assistance Partnership , University of Texas El Paso School of Public Health
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 2014 through July 31, 2017 (Extended to July 31, 2018)
Project Amount: $4,099,973
RFA: National Centers for Innovation in Small Drinking Water Systems (2013) RFA Text | Recipients Lists
Research Category: Drinking Water , Water
Objective:
Project 1: New Strategies for Technology Assessment and Implementation
- Develop and test a decision support framework to evaluate the long-term sustainability of small drinking water systems.
- Facilitate the selection of treatment technologies for small drinking water utilities that will optimize public health risk reduction and balance disinfection byproducts (DBPs) and microbial risks in drinking water – those contaminant groups that pose the greatest public health risk in the United States.
- Develop, refine and disseminate a risk reduction based strategy that will facilitate improvements in the effectiveness and sustainability of small drinking water systems throughout the U.S.
Project 2: Application of photochemical processes for the design and implementation of sustainable treatment for small systems
- Explore the applications of photochemical processes, including both sunlight and engineered light sources, to advance water quality and provide effective photon-based treatment for small systems
Project 3: Extended Biofiltration for the Control of Microbial Contaminants and Disinfection By-Products
- Reduce the risk associated with surges in particulate matter, an indicator of microbial contaminants, in source water and in settled water using innovative filter options that also allow for the control of DBP precursors and preformed DBPs.
Project 4: Distribution System Innovations
- Innovative aeration system designed and tested that is installed in the distribution water mains and can effectively remove THMs without de-pressurizing the system or be dependent on a conveniently located storage tank
- Models created for predicting THM removal using vertical in-line diffused aeration (VILDA) and horizontal in-line diffused aeration (HILDA) with consideration to the air to water (A:W) ratio, pressure and mixing intensity variables.
- A Henry’s Law 2nd order predictive model was developed as a function of pressure (up to 70-psig).
- Field test completed for VILDA or HILDA systems and operational conditions, practical configurations and costs were ascertained.
- Developed and piloted data integration tool (RTX:LINK) in three sites (Milford, OH, Henderson KY, and Flint MI). The tool’s web-based analytics dashboards help utilities manage distribution residence times, and disinfectant residual and DBP concentrations by monitoring real-time data such as tank water quality, residence time and mixing, disinfection performance etc.
Summary/Accomplishments (Outputs/Outcomes):
Project 1: New Strategies for Technology Assessment and Implementation Outcomes
- Developed a spreadsheet-based tool that utilizes source water quality and treatment specification inputs to predict DBP health risks across multiple viable treatment technologies to achieve microbial risk protection requirements. The tool outputs relative risk reduction comparisons across alternative treatment trains based on contaminant concentrations of finished waters. Finished water qualities of alternative treatment trains are predicted using available models (e.g. USEPA Water Treatment Plant (WTP)) and those developed as a part of DeRISK Center research). The relative public health risk reductions for each technology are compared by applying the Relative Health Indicator (RHI) metric to the predicted finished water quality parameters from treatment model outputs.
- RTP-RHI tool was validated in case studies in New Hampshire.
- Developed the life cycle assessment (LCA) model framework was developed using ISO 14040 methodology that uses the following steps: (1) goal and scoping (defining the functional unit and system boundary), (2) inventory assessment (quantifying all materials, energy, and chemicals used in a treatment process using Ecoinvent LCI data), (3) impact assessment (using the U.S. EPA TRACI LCIA method), and (4) interpreted (iterating as needed and conducting sensitivity and uncertainty analyses). The model framework was implemented in a spreadsheet application.
- Developed a spreadsheet-based decision support framework, as well as guidelines for usage. The decision support tool accounts for cost, environmental impacts, health risk, and other criteria that can be described as stakeholder or community preferences. Analytic Hierarchy Process is used to weight and rank criteria that account for social, environmental, and economic sustainability of small drinking water treatment alternatives. This framework can be used to provide a systematic, consistent, and transparent decision-making process to rank technologies, based on small system needs–especially to minimize environmental and health impacts without compromising water quality or affordability.
- Developed Training Design Tool (TDT) that includes training design approaches and information needed by stakeholders to participate in the consideration of innovative drinking water technologies.
- Two web based and four phone based workshop trainings were conducted to disseminate the tool.
- 107 people were trained on the tool in the phone and web workshops.
- Created a treatment technology based GIS model from State of Alaska maintained Safe Drinking Water Information System (SDWIS) database of all small systems in rural Alaska. This framework allows geographic location and through queries identifies technology similarities between small water treatment plants. It has the capacity to improve human health and the environment by providing operators a tool to identifying nearby communities that could assist them in time of need in the case that the state-wide circuit rider or remote maintenance working program is unable to respond.
- Demonstrated LW sensors can be used reliably and accurately to control medium pressure UV systems thereby allowing 4-log virus inactivation with reduced energy consumption of about 30% while in some applications achieving reduced microbial and chemical risk reduction over the use of chlorination. This was demonstrated for systems with flows as low as 5 gpm and as high as 300 gpm.
- Installed and monitored effectiveness of UV pilot demonstration projects for a period of one year of continuous operation. Two pilots were completed and removed from the sites at HAWC-Kingston, NH using a Berson-Aquionics MP system and Bethlehem, NH using a Trojan MP. The Star Island using a Xylem LPHO is fully operational and ran for the 2017 season. The 50 gpm pilot system at HAWC in Kingston, NH was decommissioned and the utility decided to remain with chlorination. HAWC originally wanted to pilot UV to reduce chemical use and costs and to eliminate the taste and odor complaints tied to chlorination. The decision not to go with UV for the 4-log virus credit was based upon changes in company personnel as well as the realization that their distribution system protection with a secondary disinfectant was desired by the operators as extra protection for the health of their 55 plus community.
- Project 1 provides small drinking water systems with a method of making informed decisions on infrastructure modifications that will result in more effective, efficient, and sustainable operations. The spreadsheet-based model will be provided free of cost to small systems and includes a user’s guide, which shows how the model can be easily modified to better meet a specific system’s needs.
Conclusions
- The RHI model identified that as DBP regulatory compliance strategies, optimized coagulation processes and granular activated carbon (GAC) adsorption at the treatment plant were found to provide superior public health protection than GAC and aeration technologies applied within the distribution system when population-weighted RHI values were considered. The relative efficiencies of distribution system technologies tended to be equivalent to those applied at the treatment plant as evidenced by normalizing population-weighted RHI reductions.
- The LCA model incorporates detailed data on currently available technologies, and it can be easily modified to add new technologies as they are developed and made available. This framework provides the foundation to evaluate current and future technologies in order to minimize global public health and environmental impacts without compromising water quality. Small drinking water systems can evaluate treatment options unique to them (e.g., bag and cartridge filtration) and identify the most effective approach to reduce materials, chemicals, and energy use.
- The spreadsheet-based decision support framework can identify and resolve conflicts of priorities and values between and in stakeholder groups. It can also provide a systematic, consistent, and transparent decision-making process to rank and select technologies, based on small system needs–particularly to minimize environmental and health impacts without compromising water quality or affordability.
- The TDT development identified training objectives, stakeholders and their motivations, and challenges including innovative drinking water technologies when evaluating alternatives.
- The project succeeded at creating the GIS based tool using Alaska SDWIS data that can be used to generate the alliances; however, the project has been redirected to evaluate the potential implementation pitfalls associated with security risks associated with making data publicly available.
- Demonstrated that using UV for 4-log virus inactivation credit followed by chloramines can be a very cost effective and practical solution for smaller systems that have major challenges to simultaneously meet microbial and DBP risk reduction goals and that find other treatment alternatives cost, space or time to implement and operate prohibitive.
Project 2: Application of photochemical processes for the design and implementation of sustainable treatment for small systems
Outcomes
- Sampling conducted at snowmelt and tropical water field sites; evaluated effectiveness of sunlight towards the inactivation of these pathogens, and effect of sunlight on DBP formation.
- Demonstrated a concept reactor that employs photo-catalyst (TiO2 nanoparticles) coated optical fibers to photo catalytically reduce nitrate to innocuous nitrogen gases.
- Designed and implementation of a compact reactor to achieve efficient pollutant remediation with optical fibers coupled to light emitting diodes.
- Inactivation efficiencies were determined for common pathogens and surrogates irradiated by individual UV sources.
- Performed bench testing to understand the potential synergies of multi-wavelength UVLED combinations. UV sources included LEDs (light emitting diodes), a KrCl excimer lamp, and a conventional low pressure (LP) mercury lamp, medium pressure mercury lamps were also tested.
- Viral disinfection by the PearlAqua was modeled using the first application of the combined variable approach to a UV LED reactor, providing a basis for comparison of the bench validation results to pilot-scale results of quarterly virus challenge tests.
- The commercially available PearlAqua (Aquisense) UV LED disinfection reactor was installed in the slow sand filter effluent in the small drinking water treatment system in the mountain town of Jamestown, CO, and evaluated for MS2, Total Coliform, and E. coli disinfection over the course of a one-year demonstration study. The MS2 disinfection performance of the flow-through UV LED reactor was measured at various flowrates and UV transmittances (UVTs) measured at 285 nm (the wavelength emitted by the LEDs) at the bench in dechlorinated tap water. The disinfection data was modeled using the first application of the combined variable to an LED reactor to provide a basis of comparison for the longitudinal demonstration study.
- Testing completed of bench-scale (dead end flow) and pilot-scale (cross-flow) of process unit integrating ceramic membrane/ UV light.
- A full patent has been received:K Doudrick, KD Hristovski, PK Westerhoff, (2017) Photocatalytic reduction of oxo-anions, US Patent 9,751,785.
- Data and approach developed that can be used to compare, validate, and test other reactors in the rapidly developing UV LED industry.
Conclusions
- A correlation was found between dissolved organic carbon (DOC) and singlet oxygen formation rates, as DOC increased in the water so did the formation rate of singlet oxygen. Higher singlet oxygen concentrations are related to higher inactivation rates. Sunlight irradiation had minimal effect on DBP formation. However, the effect of sunlight on overall pathogen inactivation would require a lower chlorine dose overall.
- Water retention ponds are a viable pre-treatment technology to initially reduce the concentrations of pathogens and natural organic matter (NOM) by sunlight enhanced mechanisms for small systems for the inactivation of pathogens E. coli and Adenovirus Type 2, but not MS2). More barriers of control must be implemented in order for water retention ponds to treat for required MS2 inactivation.
- Flow through reactors could be designed and optimized to reduce nitrate to innocuous nitrogen gases with high quantum efficiency and low electrical energy per order of treatment (EEO) by tailoring of the photocatalyst, selectivity mechanisms, and irradiation light wavelengths
- An understanding of the existing reduction nitrate mechanisms has been developed and (2) feasibility has been demonstrated for a small scale reactor concept that enables low LED energy or sunlight uses to minimize the risk portfolio for nitrate.
- In the one year pilot study, the first commercial UV-C LED reactor (PearlAqua by AquiSense) was resilient and maintained bacterial and viral disinfection performance with zero maintenance, with an electrical cost estimated to be < $25 treating 0.5 lpm continuously for one year.
- No electrical or disinfection synergies were observed for simultaneous LED exposure disinfection.
- For UV-C LEDs to match the electrical efficiency per order of log reduction of conventional LP UV sources, they must reach efficiencies of 25–39% or be improved on by smart reactor design.
- Synergies from irradiation by sequential or simultaneous exposures of multiple UV sources were investigated. Synergy was demonstrated for sequential exposures for MS2 virus disinfection, incorporating the LP or excimer lamp before LEDs. The excimer lamp, even in current prototypic state, rivals current mercury-based technologies for viral disinfection electrical efficiency.
- UV-C wavelength specific protein damage and genome damage was determined for MS2 and adenovirus. Protein damage across the UV spectrum was similar between the viruses, but differences were observed in genome damage across wavelengths between the viruses and between previously published and currently investigated quantification methods (PCR previously versus ELISA currently).
- All compounds exhibited increased degradation when utilizing both the membrane and either of the two types of UV light compared to just the membrane or UV lights alone.
- Some compounds demonstrated that the type of light had the largest impact on the removal of the compounds where others demonstrated that the light and even the dose were less influential than the presence of the membrane.\
- MB-VUV High Dose yielded the highest degradation, removing an average of 79.8% of the initial concentration of all compounds tested. This result was similar to the MB-VUV Low Dose result, which was only 0.02% lower, suggesting that VUV plays a significant role than LUV in the destruction of micropollutants.
- For fouling experiments with the silicon carbide membrane, TMP was improved on average 25% throughout the experiment for MB-VUV and specific flux was improved 2135% over MB-NUV experiments.
Project 3: Extended Biofiltration for the Control of Microbial Contaminants and Disinfection By-Products
Outcomes
- J ar test & bench scale tests completed to evaluate enhancements to course media roughing filters that elevate year-round removals of pathogenic microorganisms, especially organic DBP precursors over conventional gravel roughing filters, and to slow-rate biofilters treating low organic carbon source waters.
- Explored how to increase filter biomass by determining the groundwater rate-limited nutrients, especially organic carbon substrate and low-dose ferric ion additions, and (ii) assessed biofilter E. coli removals as a function of biomass development
- Bench scale tests completed to evaluate the control of DBPs and DBP precursors by extending the EBCTs up to 30 minutes
- Biofilters in UCB pilot plant used to evaluate DBP precursor removal and control of surges in particulate matte
- Extended EBCT filter implemented in a small water system in Jamestown, CO
Conclusions
- The most popular configurations of gravel roughing filters (GRFs) are (i) vertical-upflow (VGRF) and horizontal (HGRF).
- Filamentous and suspended algae can enhance particle removal by GRFs and lessen the impact of water quality spikes but maintaining a monoculture or establishing uniform surface coverage of the GRF with the desired algal specie was problematic. Adding precursor material and other undesirable algae based by-products to the water supply reduced the desire to explore algae enhancements further.
- Biofilter active biomass was increased by the addition of nutrients, especially organic substrates.
- The addition of a readily biodegradable organic substrate (e.g. glucose-glutamic acid) may favor the growth of specific microbes, such as some fungus species.
- The addition of more complex organic substrate, e.g. powdered milk, can result in a more diverse bacterial community which can inhibit or reduce fungus development.
- E. coli removals was positively correlated to ferric ion addition and especially active, diverse biomass as quantified by ATP and DNA analysis.
- With each source water, DOC removal was highest at the 30 min EBCT compared to the 5 min and 15 min EBCT, which supported our hypothesis of longer EBCTs increase DOC removal.
- DOC removal was highest at the warm temp (28°C) compared the colder temperatures (6 and 22 °C).
- An increase in EBCT from 5 to 30 min improved DOC removals by 5-6% (n=14). An increase in temperature from 6°C to 28 °C improved DOC removals by 5-9% (n= 9). DOC origin, e.g., terrestrial, microbial or wastewater effluent, did not impact biodegradation, as the same DOC removal was observed for each source with the similar influent DOC. Each water had a different extent of reaction, as measured by BDOC fraction, yet Barker Reservoir had slightly higher kinetics than Wonderland Lake and Boulder Wastewater Treatment Plant Effluent. SUVA did not correlate well with biodegradation potential in the range of 1.6 – 2.9 (L/mg-C/m) nor did SUVA correlate with DBPs formed. However, SUVA did prove to be a useful indicator of DBP yields. DBP precursors were best controlled during longest EBCTs as higher biodegradation of the organic matter occurred.
Project 4: Distribution System Innovations
Outcomes
- Innovative aeration system designed and tested that is installed in the distribution water mains and can effectively remove THMs without de-pressurizing the system or be dependent on a conveniently located storage tank.
- Models created for predicting THM removal using vertical in-line diffused aeration (VILDA) and horizontal in-line diffused aeration (HILDA) with consideration to the air to water (A:W) ratio, pressure and mixing intensity variables.
- A Henry’s Law 2nd order predictive model was developed as a function of pressure (up to 70-psig).
- Field test completed for VILDA or HILDA systems and operational conditions, practical configurations and costs were ascertained.
- Developed and piloted data integration tool (RTX:LINK) in three sites (Milford, OH, Henderson KY, and Flint MI). The tool’s web-based analytics dashboards help utilities manage distribution residence times, and disinfectant residual and DBP concentrations by monitoring real-time data such as tank water quality, residence time and mixing, disinfection performance etc.
- LINK technology platform usefully interprets and visualizes real-time data, elevating awareness of water quality and operational efficiency issues and potential solutions, and ultimately leading to confidence that an increased investment in information infrastructure will pay dividends for the small utility.
- All three participating utility pilot sites continued to use the LINK tool after conclusions of pilot.
- Utility staff participating in the pilot began to customize the dashboards within a week of installation, demonstrating an unmet demand to access real-time data related to critical performance measures of filter performance and disinfection residual.
- The most interesting analytics applications (for utilities engaged in pilot installations) automated the most common analyses performed by utility staff or addressed specific regulatory needs. The software frameworks that have been developed allow these, and other similar calculations, to be made available as automated real-time analyses, instead of periodic manual calculations.
- In discussion with the state of Kentucky regarding expanded use of RTX:LINK to modernize their statewide application of Partnership for Safe Water methods and goals, through automation of filter performance data collection and analytics.
Conclusions
- THMs are more difficult to remove by aeration at elevated pressures than at atmospheric pressures.
- Removal predictions (up to 38%) were reasonably verified for typical A/W ratios (0-20) and pressures ranging between 40 - 70 psig for both a batch and continuous VILDA system using a mass balance approach.
- In-line diffused aeration is a fast treatment process. EBCTs required to reach THM saturation removals by in-line diffused aeration systems are typically <18 sec. Saturation residence times appear to be slightly influenced by direction of water flow. Actual residence times required to reach saturation removals by VILDA was 3-6 sec while HILDA took 5-16 sec.
- The total capital costs for an automated VILDA system treating 500 gpm was roughly $250,000. Other findings were that air compressors are the most significant capital cost and the operation costscan be significantly higher than the capital cost itself if the system has to be operating continuously. It was also found that the cost of treatment per gpm decreases logarithmically as the VILDA system capacity increases.
- Experimental results show that adsorption with bituminous GAC is an effective treatment strategy for the removal of TOC and TTHMs through at least 6,000 bed volumes (42 days at 10min EBCT) and often longer depending on influent conditions. Pore surface diffusion model (PSDM) analysis indicated that the presence of both natural organic matter (NOM) and co-solutes are important to consider when analyzing THM breakthrough, with THM adsorbability being the most important factor in determining breakthrough order (TCM< DCBM < DBCM< TBM) and influent concentration determining localized breakthrough. Experimental HAA adsorption results were nonsystematic (see Error! Reference source not found.)
- In biofiltration pilot runs, DCAA and TCAA made up >85% of HAA5. Experimental DCAA removal between 83%-97% was reported at all EBCTS (5, 10 and 20min) for the duration of the pilot runs. TCAA removal ranged between 50%-78% at 5 minute EBCT, 80%-96% at 10 minute EBCT and 93%-98% at 20 minute EBCT. No THM biodegradation was observed. HAA reduction and reformation results indicated that biofiltration is an effective treatment for the reduction in HAA5 both immediately after biofiltration as well as at the end of the distribution system, across many ranges of chlorinated influent bromide and TOC conditions.
- A wide variety of useful treatment plant and distribution system operational performance measures, previously assumed to require laborious data analysis exercises, can now be fully automated using freely available open-source software tools developed with support from the DeRisk Center. Such a capability is necessary, if real-time data is to be routinely and effectively leveraged for public health protection, and help move the water utility culture to a flexible and adaptive one that emphasizes optimizing performance.
Journal Articles: 15 Displayed | Download in RIS Format
Other center views: | All 116 publications | 15 publications in selected types | All 15 journal articles |
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Garcia-Segura S, Lanzarini-Lopes M, Hristovski K, Westerhoff P. Electrocatalytic reduction of nitrate:Fundamentals to full-scale water treatment applications. APPLIED CATALYSIS B-ENVIRONMENTAL 2018;236:546-568. |
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Jones C, Terry L, Summers R, Cook S. Environmental life cycle comparison of conventional and biological filtration alternatives for drinking water treatment. ENVIRONMENTAL SCIENCE-WATER RESEARCH & TECHNOLOGY 2018;4(10):1464-1497. |
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Jones C, Meyer J, Comejo P, Hogrewe W, Seidel C, Cook S. A new framework for small drinking water plant sustainability support and decision-making. SCIENCE OF THE TOTAL ENVIRONMENT 2019;695. |
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Ling, L., Tugaoen, H., Brame, J., Sinha, S., Li, C., Schoepf, J., Hristovski, K., Kim, J., Shang, C., Westerhoff, P., (2017). Coupling Light-Emitting Diodes with Photocatalyst-Coated Optical Fibers Improves Quantum Yield of Pollutant Oxidation. Environmental Science and Technology 2017; 51 (22), 13319–13326 . |
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Meyer J, Seidel C, Summers R. Evaluation of Population-Weighted Risk Reduction for Several Disinfection By-Product Control Strategies. JOURNAL OF ENVIRONMENTAL ENGINEERING 2020;146(3). |
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Oxenford JL, Barrett JM. Understanding small water system violations and deficiencies. Journal of the American Water Works Association 2016;108(3):31-37. |
R835603 (2016) R835603 (2017) |
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Stewart, J.R., Livneh, B., Kasprzyk, J.R., Rajagopalan, B., Minear, J.T. and Raseman, W.J., 2017. A multi-algorithm approach to land surface modeling of suspended sediment in the Colorado Front Range. Journal of Advances in Modeling Earth Systems 2017; 9(7):2526-2544. |
R835603 (2017) R835865 (2017) R835865 (2018) R835865 (Final) |
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Terry, L. G., and Summers, R. S. Biodegradable organic matter and rapid-rate biofilter performance:A review. Water Research 2018;128, 234–245. |
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Terry L, Peterson E, Summers RS. Organic matter biofiltration performance modeling:Influence of influent water quality, operating conditions, and biomass. WATER RESEARCH 2024;249(121006). |
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Tugaoen, H., Garcia-Segura, S., Hristovski, K., Westerhoff, P., Challenges in photocatalytic reduction of nitrate as water treatment technology. Science of the Total Environment 2017; 599: 1524–1551. |
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Tugaoen H, Garcia-Segura S, Hristovski K, Westerhoff P. Challenges in photocatalytic reduction of nitrate as a water treatment technology. SCIENCE OF THE TOTAL ENVIRONMENT 2017;599:1524-1551. |
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Tugaoen, H., Garcia-Segura, S., Hristovski, K., Westerhoff, P., Compact light-emitting diode optical fiber immobilized TiO2 reactor for photocatalytic water treatment. Science of the Total Environment 2018;613:1331–1338. |
R835603 (2017) |
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Tugaoen, H., Herckes, P., Hristovski, K., Westerhoff, P., Influence of ultraviolet wavelengths on kinetics and selectivity for N-gases during TiO2 photocatalytic reduction of nitrate. Applied Catalysis B-Environmental 2018;220: 597–606 |
R835603 (2017) |
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Beck SE, Ryu H, Boczek L, Cashdollar J, Jeanis K, Rosenblum J, Lawal O, and Linden K (2017). Evaluating UV-C LED disinfection performance and investigating potential dual-wavelength synergy. Water Research 2017;109;207-216. |
R835603 (2017) |
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Hull NM, Linden KG. Synergy of MS2 disinfection by sequential exposure to tailored UV wavelengths. Water research 2018;143:292-300, DOI:j.watres.2018.06.017. |
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Supplemental Keywords:
gravel roughing filters, anion exchange resin, zero valent iron, algal seedings, magnesium clarification, pretreatment clarification, organic precursor removals, Biofilter; Filter Depth; Natural Organic Matter; drinking water; DOC removal, trihalomethanes, in-line diffused aeration, pressurized, distribution system, water mains, carbon dioxide, Risk reduction; Disinfection byproducts; Decision support, Lifecycle Analysis; Source Water Quality; Decision Support, Environmental Sustainability, SDWIS, GIS Model low UV wavelengths monitoring, MP UV, LPHO UV, UV-chloramines, virus inactivation, disinfection by-products, surface waters, groundwaters, rainwater disinfection, Sustainable small water systems, Photochemical Inactivation, Retention Pond, nitrate reduction, photocatalysis, electrical energy per order, quantum yield, photon fluence, hole scavenger Disinfection, UV LED, KrCl excimer lamp, water treatment, drinking water, virus, microbiome, Vacuum UV, Ceramic Membranes, Ceramic Membrane Filtration, UV-Membrane, Biofilter; Filter Depth; Natural Organic Matter; drinking water; DOC removal, Smart water systems; data analytics; data integration; SCADA historian; database; dashboard.Relevant Websites:
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Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.