Grantee Research Project Results
Final Report: NiTreat: Nitrate Removal from Drinking Water
EPA Grant Number: SU836770Title: NiTreat: Nitrate Removal from Drinking Water
Investigators: Jassby, David
Institution: University of California - Riverside
EPA Project Officer: Page, Angela
Phase: I
Project Period: September 1, 2016 through August 31, 2017
Project Amount: $14,308
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2016) RFA Text | Recipients Lists
Research Category: Sustainable and Healthy Communities , P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources
Objective:
The primary goal of this project was to design and build a water treatment system capable of removing high amounts of nitrate in drinking water sources. The health consequences associated with ingesting high amounts of nitrates are methemoglobinemia, sudden infant death syndrome (SIDS), thyroid disorders, and specific types of cancers. Additionally, current nitrate remediation technology poses an environmental threat. Current treatment technologies- such as reverse osmosis and ion exchange - require waste by-product permits for proper waste disposal. The possibility of mishandling high amounts of waste by-product could lead to environmental consequences. In coastal states, brine diffusion into the ocean could lead to hypoxia or algal blooms, if brine loading exceeds the current ocean nutrient limit. However, inland states face a problem for introducing contaminants into untapped aquifers through deep-well injection. Lastly, the high treatment cost of nitrate remediation could financially strain overburdened treatment facilities. This financial issue could lead water facilities to intermittently shut-off water treatment to balance operational costs, possibly exposing communities to highly nitrated water. Thus, a simple and efficient approach was taken by the team to provide a novel technology for nitrate remediation. The team constructed an electrochemical-mediated packed bed reactor. The system consists of titanium metal as the electrodes and granular activated carbon as the filter media. Activated carbon is a known filtration media in the water treatment industry. However, activated carbon is an ineffective method for nitrate reduction. Through the application of an electric potential of +5 volts onto the granular activated carbon, the team hopes to increase nitrates’ affinity onto the carbon’s surface. The main objective of the group was to investigate the capability of the system at remediating nitrate contamination. Additionally, the team wanted to explore the main nitrate mechanism of the system and its waste by-products.
Summary/Accomplishments (Outputs/Outcomes):
An outcome of this project was the development and demonstration of the removal of nitrate from drinking sources using an electrochemical system. The developed system was tested at 90 and 20 mg∙l nitrate-N in tap water, concentrations above the EPA maximum contaminant level (MCL) of 10 mg∙l nitrate-N6. Using only a single-pass through the electrochemical system costing approximately $5 to construct and an energy consumption of $ 0.09/m3 of treated water, the team’s system could generate 8 liters of nitrate free water treating an initial concentration of 20 mg∙l nitrate-N and 2.5 liters of nitrate free water treating an initial concentration of 90 mg∙l nitrate-N. The ability of this electrochemical system to treat low and high concentrations of nitrated water with minimal costs to the consumer demonstrates the robustness and cost-effectiveness of this system. With these findings, delivering affordable drinking water to communities affected by the persistent and growing levels of nitrate in their drinking water shows promise to be an attainable goal for this project.
Conclusions:
The EPA P3 Phase I team has successfully designed a filtration unit capable of amplifying nitrate's affinity onto the granular activated carbon surface. Additionally, chemical transformation of nitrate to a possible nitrogen derivative was observed. Harmful nitrogen derivatives - such as nitrite, ammonium, and NOx - were not found in the effluent. Thus, the team posits that a transformation mechanism of nitrate to nitrogen gas was a possibility. The system could treat 90 and 20 mg∙L-1 of nitrate-N, producing clean drinking water at 2.5L and 8L, respectively. Subsequent runs required a regeneration phase, where the regenerative quality of the filtration column was exhibited. The team intends to promote overall health by reducing nitrate levels in drinking water resources. This novel filtration column would be highly beneficial to the communities plagued with highly-nitrated drinking water. The team expects to provide an ecologically cost-effective system by reducing waste streams while providing safer drinking water.
Journal Articles:
No journal articles submitted with this report: View all 1 publications for this projectSupplemental Keywords:
People, sustainability, nitrate, water contamination, pollution, methemoglobinemia, hypoxia, dead zones, activated carbon, brine, cost-effective, wells, septic tanks, agriculture, runoff, low income, rural, electrochemical, reverse osmosis, ion exchange, potable, brine injections, algal bloomsThe 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.