Grantee Research Project Results

2022 Progress Report: Solving the Arsenic Problem in Rural California

EPA Grant Number: SV840384
Title: Solving the Arsenic Problem in Rural California
Investigators: Gadgil, Ashok
Institution: University of California - Berkeley
EPA Project Officer: Aja, Hayley
Phase: II
Project Period: April 1, 2022 through March 31, 2024
Project Period Covered by this Report: April 1, 2022 through March 31,2023
Project Amount: $99,998
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2022) Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources

Objective:

A decentralized approach to water treatment can provide utility and empowerment to each community facing their water quality challenges. Electrochemical technologies for water treatment can be designed, modularized, and integrated within existing treatment trains or function as standalone systems. The overall objective of this research is to bring closer to maturation a novel technology, “air cathode assisted iron electrocoagulation” (abbreviated as ACAIE) for arsenic remediation of drinking water in small rural US communities.  ACAIE has fast kinetics, small footprint, and aims to be simple to operate.  With greater demands for, and a decreasing supply of, clean drinking water in the Central Valley, high-throughput technology at an affordable price would be highly desirable.

The project objectives are:

1) Operate ACAIE continuously and effectively reduce high arsenic concentrations for a 2-month duration in Allensworth, California.

2) Install sensors enabled for data collection and remote monitoring.

3) Conduct high-resolution cost analysis of ACAIE community-scale plant.  

4) Evaluate the community’s receptivity to ACAIE technology and engage community through a STEM education program.

Progress Summary:

During the reporting period,

(1) We completed the design, building, and testing (at a field station of UC Berkeley) of a 600 Liters per Hour (LPH) ACAIE system, making it ready for moving to Allensworth for commissioning and field test in Allensworth, CA. The stack of ACAIE reactors capable of treating 600 LPH was integrated with suitable flocculation and filtration units in a small spatial footprint.

(2) After commissioning, the treatment system was operated routinely, and samples collected to monitor arsenic concentrations at the inlet and outflow. Other parameters such as flow rates, pH, turbidity, iron concentration, arsenic and H₂O₂ concentrations at various points in the treatment train, and voltage, current, and total power consumption were periodically measured. Evaluation of the long-term operation shows the technology performed effectively in arsenic remediation.

(3) However, at no point during this phase, the ACAIE-treated (i.e., arsenic-remediated) water was made available for human consumption.

(4) The plant operated as Zero Liquid Discharge. More than 99% of arsenic in the inlet water was captured and removed, attached to solid (moist) sludge, primarily comprising precipitated Fe(III) hydroxide.  This sludge was handled and disposed of per a plan for its safe management: it was transported and disposed of (meeting the EPA and State of California guidelines) in the UC Berkeley laboratory waste stream.

(5) Prof. Winston Tseng team offered supplemental STEM education modules related to water, at the local K-8 school in Allensworth, for the academic year 2022-2023. The STEM curriculum included: Introduction to Water; States of Matter; Watersheds and Regions; Sand Filter Experiment; Carbon Cycle; and Super Plant Project.

(6) Our current rough cost estimates (to be refined and improved in the second year) suggest that the total cost of removing arsenic from real groundwater at a community scale is affordable to the residents of rural California, and favorably compares to their current practice of purchasing drinking water.

Future Activities:

A detailed economic analysis will be undertaken in Year 2.

Journal Articles:

No journal articles submitted with this report: View all 2 publications for this project

Supplemental Keywords:

Electrochemistry, ACAIE technology, environmental justice, public health, environmental education, cancer prevention, safe drinking water, field-test

Relevant Websites:

Gadgil Lab - Arsenic Removal Exit

Berkeley News - Bringing arsenic-safe drinking water to rural California Exit

Progress and Final Reports:

Original Abstract

Final Report

P3 Phase I:

Solving the Arsenic Problem in Rural California  | 2020 Progress Report  | Final Report