Source: PANI CLEAN INC submitted to
A HYBRID ELECTRODIALYSIS/ELECTROLYSISN UNIT FOR COMBINED NITRATE REMOVAL AND CONVERSION FROM AGRICULTURAL WASTEWATER
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
SMALL BUSINESS GRANT
Reporting Frequency
Annual
Accession No.
1019399
Grant No.
2019-33610-29769
Cumulative Award Amt.
$100,000.00
Proposal No.
2019-00600
Multistate No.
(N/A)
Project Start Date
Jul 1, 2019
Project End Date
May 1, 2020
Grant Year
2019
Program Code
[8.4]- Air, Water and Soils
Project Director
Lee, J.
Recipient Organization
PANI CLEAN INC
2350 FLINTSHIRE VIEW
CORALVILLE,IA 522413609
Performing Department
(N/A)
Non Technical Summary
Nitrate is currently the most prevalent groundwater pollutant in Northern America, primarily from agricultural activities and changing nitrogen input to the land surface. State-of-the-art treatment technologies such as reverse osmosis, ion exchange, and electrodialysis, suffer from brine management cost associated with nitrate removal. The core technology developed through this SBIR project will be a hybrid electrodialysis (ED)/electrolysis (EL) unit to efficiently remove nitrates from wastewater and subsequently convert them to molecular nitrogen, thereby eliminating brine management cost. The project objectives are: (1) To develop bi-functional electrodes that operate efficiently in both electrodialysis (nitrate removal) and electrolysis (nitrate conversion) mode; (2) Assemble and test lab scale hybrid electrodialysis/electrolysis unit and evaluate their performance and durability for continuous removal and conversion of nitrates in different feed water sources.The target is to achiever nitrate conversion efficiency over 75%, fresh water recovery efficiency over 85% and energy efficiency over 75%. If successful, the proposed project will improve water recovery and reuse from agricultural return flows and improve nutrient management. An economical process of treating nitrates with no brine generation can impact more than 1000 community drinking water systems that have nitrate levels greater than maximum contaminant level of 45 mg/L.
Animal Health Component
40%
Research Effort Categories
Basic
40%
Applied
40%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
11102102020100%
Knowledge Area
111 - Conservation and Efficient Use of Water;

Subject Of Investigation
0210 - Water resources;

Field Of Science
2020 - Engineering;
Goals / Objectives
The major goal of this SBIR Phase 1 proposal is to demonstrate concept feasibility of a novel hybrid electrodialysis/electrolysis (ED/EL) unit that is economically and environmentally sustainable for removing nitrates from agricultural return flows while minimizing brine management cost.The specific objectives and milestones are as follows:Objective 1: To develop bi-functional electrodes that operate efficiently in both electrodialysis (nitrate removal) and electrolysis (nitrate conversion) mode and test their performance and durability in model nitrate rich waters.Milestone: Identification of optimal electrodes and catalysts for the electrochemical reduction of nitrate using a half-cell electrolysis set-up with target removal and conversion of >75% nitrates.Objective 2: Assemble and test 1 cm2 hybrid ED/EL in full cell configuration using optimal catalysts and electroactive supports prepared through objective 1 and evaluate their performance and durability for continuous removal and conversion of nitrates in different feed water sources.Milestone(s): Complete fabrication of 1 cm2 full-cell hybrid ED/EL unit.Performance evaluation for nitrate removal in different simulated water composition and total dissolved solids (TDS) concentration and achieve nitrate conversion efficiency >75%, fresh water recovery efficiency >85% and energy efficiency >75%.
Project Methods
To achieve our research objectives, we propose a research and development plan that builds upon team strengths in the design and synthesis of functional materials, experimental and analytical electrochemistry, and advanced water treatment processes. In general, scientific methods include:(1) Identification and development of novel hierarchical electrode/electrocatalyst assemblies that is bifunctional in nature (i.e. serves as both electrodialysis and electrolysis electrode). This will be achieved using traditional electrochemical and wet-chemical synthetic processes.(2) Characterization of electrode/electrocatalyst assemblies. The physical characterization of the assemblies will be done using electron microscopy and spectroscopy tools, while its performance characterization to remove and convert nitrates will be carried out using both DC and AC electrochemical techniques.(3) Benchmarking the electrode/electrocatalyst assemblies for nitrate removal and conversion. This will be achieved by building a lab-scaleelectrodialysis/electrolysis unit for full cell testing of nitrate removal from simulated and real nitrate rich waters. This testing will be carried out in batch and continuous mode with the simultaneous investigation on the effect of operational variables (current density, potential, pH, temperature, flow rate, etc.) on nitrate removal.

Progress 07/01/19 to 05/01/20

Outputs
Target Audience:The scope of work carried at the University of Iowa, initiated bya sponsored research agreement, provided training for a graduate student. Further, the graduate student involved in this project served as a mentor to two undergraduate researchers (unfunded) for understanding the overall challenges related towater scarcity and treatment, and the technologies for removing pollutants while minimizing wastes by conversion. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training for one graduate student (funded through Phase I) and two undergraduate student researchers (unfunded) How have the results been disseminated to communities of interest?Part of the work carried out under the SBIR Phase I funding was accepted to be presented at the American Chemical Society (ACS) conference, but the conference was canceled due to the COVID-19 pandemic. Part of the work on the electroactive support for catalyst loading and efficient removal of nitrate in an electrodialysis set-up is currently in the process of submission to a peer-reviewed journal. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Down selectedhigh surface area electrodes for electrodialysis operation and also as catalyst support layer on which nitrate conversion catalyst can be loaded for electrolysis operation. Synthesized a matrix of monometallic and bimetallic catalysts on down selected electroactive supports to test nitrate to nitrogen conversion. Benchmarking of the monometallic and bimetallic catalyst for nitrate electroreduction using an electrolysis set-up. Successfully showed that the bimetallic systems are highly active for nitrate reduction. Product quantification showed >80% selectivity for N2 production, exceeding the target metric proposed for Phase I. Completed the fabrication of 1 cm2 full-cell hybrid electrodialysis and electrolysis unit with cell resistance less than 1-ohm cm2 to minimize energy losses. Benchmarking of down-selected catalysts in 1 cm2 ED/EL unit different water chemistries. For all different feed water chemistries tested, we were able to achieve a freshwater recovery of 85% and higher. We were also able to achieve nitrate-to-nitrogen conversion efficiencies >75% for all feedwater chemistries, meeting all our Phase 1 target metrics.

Publications