Grantee Research Project Results
2014 Progress Report: Small, Safe, Sustainable (S3) Public Water Systems through Innovative Ion Exchange
EPA Grant Number: R835334Title: Small, Safe, Sustainable (S3) Public Water Systems through Innovative Ion Exchange
Investigators: Boyer, Treavor H. , Zhang, Qiong
Institution: University of Florida , University of South Florida
EPA Project Officer: Packard, Benjamin H
Project Period: August 16, 2012 through August 15, 2016 (Extended to August 15, 2017)
Project Period Covered by this Report: August 16, 2013 through August 15,2014
Project Amount: $499,361
RFA: Research and Demonstration of Innovative Drinking Water Treatment Technologies in Small Systems (2011) RFA Text | Recipients Lists
Research Category: Drinking Water , Water
Objective:
The main objective of this project is to identify and test ion exchange processes that can treat groups of chemical contaminants and evaluate their sustainability. The specific objectives of this project are to (1) identify combined anion and cation exchange processes that can treat groups of chemical contaminants in an environmentally friendly way; (2) develop an ion exchange process model that includes multi-contaminant treatment and regeneration efficiency; (3) demonstrate the performance of the ion exchange treatment and regeneration processes through pilot-scale testing at a small PWS; and (4) evaluate the environmental, human health, and economic impacts of the ion exchange treatment and regeneration processes through life cycle assessment (LCA) and life cycle cost analysis (LCCA).
Progress Summary:
Project progress is on track with the research objectives and timeline to accomplish research activities. Laboratory ion exchange experiments are underway that evaluate contaminant removal by separate and combined anion and cation exchange and subsequent regeneration (objective 1), model development of fixed bed ion exchange treatment and regeneration (objective 2), and data collection and analysis to allow for LCA and LCCA of full-scale ion exchange treatment (objective 4). Activities for research objective 1 have focused on selectivity of contaminant removal using bicarbonate-form anion exchange resin and potassium-form cation exchange resin. This follows from the research activities in year 1, which investigated the regeneration efficiency of anion exchange resin exhausted with nitrate and cation exchange resin exhausted with calcium. Sodium chloride, potassium chloride, sodium bicarbonate, and potassium bicarbonate were tested as regeneration chemicals. Since the selectivity of chloride-form anion exchange resin and sodium-form cation exchange resin is well known, new experimental data were generated on the selectivity of bicarbonate-from anion exchange resin for nitrate, sulfate, bromide, perchlorate, chromate, and dissolved organic carbon and potassium-form cation exchange resin for calcium, strontium, barium, cobalt, and cadmium. The selectivity of the anion and cation exchange resins were also investigated for a range of resin properties. Activities on research objective 2 have focused on the development of a fixed bed ion exchange treatment process model that includes regeneration. The process model has been developed and is in the process of validation. The current model can predict ion exchange breakthrough curves, regeneration efficiency, residual stream information, and so on. Activities on research objective 4 have focused on evaluating environmental and human health impacts as well as costs of conventional ion exchange systems using a life cycle approach. Drinking water treatment plants in Florida that currently utilize ion exchange have served as a case study for evaluation, particularly focusing on systems that remove organic carbon, which is a precursor for disinfection byproducts. Life cycle inventories were developed for both construction and operation phases of conventional ion exchange systems and environmental impact assessment results were calculated. Cost inventories were also developed for operation and maintenance of the systems. The assessment allowed for comparison among conventional systems, including reactor design configuration, resin choice, and scale. Furthermore, this assessment provides a basis of comparison, to ensure that novel ion exchange designs provide environmental and economic improvements over conventional ion exchange technology.
Future Activities:
The following activities will take place during the next reporting period (i.e., year 3): laboratory ion exchange experiments as part of research objective 1 will be completed, the ion exchange process model developed as part of research objective 2 will be expanded to include other reactor configurations and multiple contaminant removal, design of the ion exchange pilot plant system (research objective 3) will take place during year 3 with the goal of stating pilot testing in summer 2015 (i.e., second half of year 3), the evaluation of conventional ion exchange systems will be completed (research objective 4) and the process model will be linked with LCA to include dynamic evaluation of alternate scenarios during the first half of year 3, and the evaluation of novel systems will take place during the second half of year 3. The laboratory experiments (research objective 1) will investigate combined ion exchange treatment and regeneration under continuous flow column conditions. The ion exchange process model (research objective 2) will be adapted to allow for different reactor configuration for treatment (fixed bed, fluidized bed, completely mixed flow reactor) and regeneration (fixed bed, completely mixed batch reactor). The ion exchange process model will also be extended to multiple contaminants. The ion exchange pilot plant study (research objective 3) will be designed to investigate the scale-up behavior of the laboratory experiments, allow for validation of the ion exchange process model, and provide inventory data for LCA and LCCA work. The integrated process model for conventional systems (research objective 2) will be linked with LCA (research objective 4) to evaluate alternate scenarios (reactor configuration, operating condition), and data on the novel ion exchange processes will be obtained from the laboratory experiments (research objective 1) and the pilot plant study (research objective 3) to allow for preliminary environmental impact assessment (research objective 4).
Journal Articles on this Report : 1 Displayed | Download in RIS Format
Other project views: | All 37 publications | 7 publications in selected types | All 7 journal articles |
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Type | Citation | ||
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Maul GA, Kim Y, Amini A, Zhang Q, Boyer TH. Efficiency and life cycle environmental impacts of ion-exchange regeneration using sodium, potassium, chloride, and bicarbonate salts. Chemical Engineering Journal 2014;254:198-209. |
R835334 (2014) R835334 (2015) R835334 (Final) |
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Supplemental Keywords:
Nitrate, softening, regenerant brine, salinity, life cycle assessment (LCA), mining, freshwater toxicity, sodic soil, wastewater nitrificationRelevant Websites:
Boyer Research Group Water Sustainability Exit
Treavor H. Boyer Exit
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.