Solving the Arsenic Problem in Rural California

EPA Grant Number: SU839960
Title: Solving the Arsenic Problem in Rural California
Investigators: Gadgil, Ashok , Kumar, Arkadeep , Hernandez, Dana , Majmudar, Jay , Duffy, Lucas , Nahata, Mohit , Bandaru, Siva , Tseng, Winston
Current Investigators: Gadgil, Ashok , Tseng, Winston , Kumar, Arkadeep , Nahata, Mohit , Hernandez, Dana , Bandaru, Siva , Duffy, Lucas , Majmudar, Jay
Institution: University of California - Berkeley
EPA Project Officer: Callan, Richard
Phase: I
Project Period: October 1, 2019 through September 30, 2020 (Extended to September 30, 2021)
Project Amount: $25,000
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2019) RFA Text |  Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources

Description:

An estimated 55,000 people in California rely on public water systems that are out of compliance with respect to arsenic. Low income, mostly minority communities bear a disproportionate burden of these high arsenic carcinogen levels in drinking water, which are above the EPA -Maximum Contaminant Level (MCL) of 10 parts per billion (ppb). This project's technical challenge is to effectively remove arsenic from contaminated groundwater at a high throughput to meet the water demands of rural California.

Iron Electrocoagulation (Fe-EC) systems have shown to effectively remove high concentrations of arsenic from contaminated groundwater sources. Fe-EC relies on the controlled electrolytic dissolution of an Fe anode in an electrochemical cell to form Fe precipitates that adsorb the contaminant of concern. However, Fe-EC is limited by slow Fe(II) oxidation kinetics due to the depletion of dissolved oxygen in the bulk solution. A promising solution, called Air Cathode Assisted Iron Electrocoagulation (ACAIE), is based on Fe-EC, but also induces the oxygen reduction reaction (ORR) at the cathode to produce large amounts of hydrogen peroxide, H2O2, in-situ, a more powerful oxidant than oxygen. Thus, the process overcomes the problem of oxygen depletion through the abundance of H2O2in the reactor. In the process, As(III) is oxidized to As(V), a more readily adsorbed form of inorganic arsenic. The arsenic laden iron sludge is then settled out, producing arsenic-safe drinking water.

Objective:

The main objective of this proposal is to further develop this technology in the laboratory, for a high throughput system. While ACAIE began as a 500 mL volume batch reactor, the technology has now scaled up to a 60 liter per hour (LPH) continuous flow system. For the proposal period, 2019-2020, our specific objectives are the following: 1) Demonstrate arsenic removal from very high initial concentrations of 250 ppb of As(III), which is the more difficult species of inorganic arsenic to remove, to below the EPA-MCL in a synthetic groundwater matrix mimicking the composition of contaminated aquifers in California, 2) Design and optimize a compact, stacked continuous flow system that produces 600 LPH of arsenic-safe water, 3) Initiate efforts for subsequent Community-Engaged Research by reaching out to central valley communities in rural California, and 4) Conduct an economic analysis to estimate the total cost of removing arsenic from the water at a community-scale plant in California.

Approach:

The activities conducted in this project with relevance to the P3 approach are as follows: 1) People: technology development towards future implementation to improve drinking water quality, 2) Prosperity: development of an affordable technology for low-income communities without the production of hazardous waste in the process, and 3) Planet: technology development while engaging the local community, spreading knowledge regarding the importance to conserve safe drinking water sources, and introducing sustainable approaches to protect the health of exposed communities. Furthermore, this project may potentially be introduced in a course taught by Prof. Gadgil called Design, Evaluate and Scale Developmental Technologies in which Master of Business Administration (MBA) students, Master of Development Practice (MDP) students, and graduate students of several engineering departments participate. This will further disseminate awareness of the arsenic problem and stimulate creative discussion on sustainable solutions.

Expected Results:

The expected output of the project will be the production of arsenic safe drinking water using ACAIE at 600 LPH in the laboratory in synthetic groundwater and high charge dosage rates. Product water will be tested before and after treatment using ICP-OES and ICP-MS. In Phase I we will hold an informational meeting with the school community (teachers, parents, public officials) and administer a brief survey to assess their intent to collaborate with our project. We will also organize a follow-up meeting and evaluate the receptivity from the community to form a community advisory board (CAB) potentially for Phase II.

Apart from the final arsenic levels in treated water, a data set containing operating parameters (i.e. dosage rates, voltage, conductivity, pH) and system design will indicate arsenic removal performance and energy consumption. A manuscript to be published in a peer-reviewed journal will be prepared at the end of the grant period with the data collected. If phase 1 proposal is funded and successful, future work would involve a field scale demonstration of ACAIE as a modular, decentralized water treatment device that can serve the needs of low-income, disadvantaged communities in rural California. Long term outcomes in the future may include 1) decreased cancer rates 2) decreased financial burdens, and 3) increased water conservation efforts. These could be assessed via public health records, household surveys, and changes in local policy regarding water usage.

Publications and Presentations:

Publications have been submitted on this project: View all 6 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 1 journal articles for this project

Supplemental Keywords:

electrochemistry, surface chemistry, iron nanoparticles, safe drinking water, public health, cancer prevention, environmental justice, environmental education

Progress and Final Reports:

  • 2020 Progress Report