The effects of different carbon sources on microbial mediation of arsenic in arsenic-contaminated sediment.
Changes in speciation and mobility of As by indigenous bacteria in As-contaminated sediments (339 mg/kg) from an abandoned Au-Ag mine area in Korea were investigated after biostimulation with a variety of carbon sources, including acetate, lactate and glucose in batch experiments. Sequential extraction analysis designed to determine the form of As occurrence revealed that 40 and 47% of As were present in the sediment as Fe-associated and residual fractions, respectively. After 22-day incubation with acetate and lactate, the presence of indigenous bacteria increased the amount of total dissolved As from both Fe-associated and residual fractions in the sediment. More than 99% of dissolved As existed as As(V) in biotic slurries in contrast to sterile controls (less than 50% of total dissolved As), which indicated that indigenous bacteria transformed some dissolved As(III) to As(V). In real environments, depending on the pH, microbially-produced aqueous As(V) may be either immobilized through adsorption or reduced to As(III) after migration to the anoxic subsurface.
Lee
Jong-Un
JU
Department of Civil, Geosystem and Environmental Engineering, Chonnam National University, Gwangju 500-757, Korea. jongun@chonnam.ac.kr
Lee
Sang-Woo
SW
Kim
Kyoung-Woong
KW
Yoon
Chung-Han
CH
D000085:Acetates / Q000378:metabolism; D001151:Arsenic / Q000737:chemistry / Q000378:metabolism*; D018053:Arsenites / Q000737:chemistry / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism; D001711:Biotransformation; D002244:Carbon / Q000737:chemistry / Q000378:metabolism*; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology*; D007723:Korea; D019344:Lactic Acid / Q000378:metabolism; D008906:Mining; D012834:Silver / Q000737:chemistry / Q000378:metabolism; D013997:Time Factors
D000085:Acetates; D018053:Arsenites; D019344:Lactic Acid; D012834:Silver; D002244:Carbon; D001151:Arsenic