Arsenic control during aquifer storage recovery cycle tests in the Floridan Aquifer.
Ground Water
; 51(4): 539-49, 2013.
Article
in En
| MEDLINE
| ID: mdl-23106789
ABSTRACT
Implementation of aquifer storage recovery (ASR) for water resource management in Florida is impeded by arsenic mobilization. Arsenic, released by pyrite oxidation during the recharge phase, sometimes results in groundwater concentrations that exceed the 10 µg/L criterion defined in the Safe Drinking Water Act. ASR was proposed as a major storage component for the Comprehensive Everglades Restoration Plan (CERP), in which excess surface water is stored during the wet season, and then distributed during the dry season for ecosystem restoration. To evaluate ASR system performance for CERP goals, three cycle tests were conducted, with extensive water-quality monitoring in the Upper Floridan Aquifer (UFA) at the Kissimmee River ASR (KRASR) pilot system. During each cycle test, redox evolution from sub-oxic to sulfate-reducing conditions occurs in the UFA storage zone, as indicated by decreasing Fe(2+) /H2 S mass ratios. Arsenic, released by pyrite oxidation during recharge, is sequestered during storage and recovery by co-precipitation with iron sulfide. Mineral saturation indices indicate that amorphous iron oxide (a sorption surface for arsenic) is stable only during oxic and sub-oxic conditions of the recharge phase, but iron sulfide (which co-precipitates arsenic) is stable during the sulfate-reducing conditions of the storage and recovery phases. Resultant arsenic concentrations in recovered water are below the 10 µg/L regulatory criterion during cycle tests 2 and 3. The arsenic sequestration process is appropriate for other ASR systems that recharge treated surface water into a sulfate-reducing aquifer.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Arsenic
/
Water Pollutants, Chemical
/
Groundwater
/
Water Quality
/
Water Purification
/
Conservation of Natural Resources
Type of study:
Evaluation_studies
Country/Region as subject:
America do norte
Language:
En
Journal:
Ground Water
Journal subject:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Year:
2013
Document type:
Article
Affiliation country:
Estados Unidos