EPA Science Inventory

Water Chemistry Impacts on Arsenic Mobilization from Arsenopyrite Dissolution and Secondary Mineral Precipitation: Implications for Managed Aquifer Recharge

Citation:

Neil, C., J. Yang, D. Schupp, AND Y. Jun. Water Chemistry Impacts on Arsenic Mobilization from Arsenopyrite Dissolution and Secondary Mineral Precipitation: Implications for Managed Aquifer Recharge. ENVIRONMENTAL SCIENCE AND TECHNOLOGY. John Wiley & Sons, Ltd., Indianapolis, IN, 48(8):4395-4405, (2014).

Description:

Managed Aquifer Recharge (MAR) is one water reuse technique with the potential to meet growing water demands. However, MAR sites have encountered arsenic remobilization resulting from recharge operations. To combat this challenge, it is important to identify the mechanism of arsenic remobilization during MAR. In this bench-scale study, arsenic remobilization from arsenopyrite (FeAsS) was characterized for conditions relevant to MAR operations. Experimentally determined activation energies for arsenic remobilization from FeAsS under aerobic conditions were 36.87 ± 2.27 kJ/mol for 10 mM sodium chloride, and 40.81 ± 3.52 kJ/mol for 10 mM sodium nitrate, and 43.63 ± 4.98 kJ/mol for secondary effluent from a wastewater treatment plant. In addition, sodium chloride had higher arsenic remobilization under aerobic conditions. Interestingly, secondary mineral precipitation varied between systems and further affected arsenic remobilization. For example, the wastewater system inhibited precipitation, while faster phase transformation of iron(III) (hydr)oxide precipitates was observed in the sodium chloride system, resulting in hematite formation after 7 days in this system only. The transformation would result in less available surface area for arsenic attenuation. Together, these new observations and calculated activation energies can be used to model arsenic reactive transport during MAR and develop scenarios to minimize arsenic release.

Purpose/Objective:

Communicate to the science and technical community of EPA research results on aquifer storage and recharge impacts on groundwater quality

URLs/Downloads:

http://dx.doi.org/10.1021/es405119q   Exit

Record Details:

Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Start Date: 04/15/2014
Completion Date: 04/15/2014
Record Last Revised: 04/22/2014
Record Created: 04/16/2014
Record Released: 04/16/2014
OMB Category: Other
Record ID: 273437

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL RISK MANAGEMENT RESEARCH LABORATORY

WATER SUPPLY AND WATER RESOURCES DIVISION

URBAN WATERSHED MANAGEMENT BRANCH