Biogeochemical environments of streambed-sediment pore waters withand without arsenic enrichment in a sedimentary rock terrain, New Jersey Piedmont, USA

Science of the Total Environment
By: , and 

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Abstract

Release of arsenic (As) from sedimentary rocks has resulted in contamination of groundwater in aquifers of the New Jersey Piedmont Physiographic Province, USA; the contamination also may affect the quality of the region's streamwater to which groundwater discharges. Biogeochemical mechanisms involved in the release process were investigated in the streambeds of Six Mile Run and Pike Run, tributaries to the Millstone River in the Piedmont. At Six Mile Run, streambed pore water and shallow groundwater were low or depleted in oxygen, and contained As at concentrations greater than 20μg/L. At Pike Run, oxidizing conditions were present in the streambed, and the As concentration in pore water was 2.1μg/L. The 16S rRNA gene and the As(V) respiratory reductase gene, arrA, were amplified from DNA extracted from streambed pore water at both sites and analyzed, revealing that distinct bacterial communities that corresponded to the redox conditions were present at each site. Anaerobic enrichment cultures were inoculated with pore water from gaining reaches of the streams with acetate and As(V). As(V) was reduced by microbes to As(III) in enrichments with Six Mile Run pore water and groundwater, whereas no reduction occurred in enrichments with Pike Run pore water. Cloning and sequencing of the arrA gene indicated 8 unique operational taxonomic units (OTUs) at Six Mile Run and 11 unique OTUs at Pike Run, which may be representative of the arsenite oxidase gene arxA. Low-oxygen conditions at Six Mile Run have favored microbial As reduction and release, whereas release was inhibited by oxidizing conditions at Pike Run.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Biogeochemical environments of streambed-sediment pore waters withand without arsenic enrichment in a sedimentary rock terrain, New Jersey Piedmont, USA
Series title Science of the Total Environment
DOI 10.1016/j.scitotenv.2014.07.104
Volume 505
Year Published 2015
Language English
Publisher Elsevier
Contributing office(s) New Jersey Water Science Center
Description 11 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Science of the Total Environment
First page 1350
Last page 1360
Country United States
State New Jersey
Online Only (Y/N) N
Additional Online Files (Y/N) N