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.
Department of Civil, Geosystem and Environmental Engineering, Chonnam National University, Gwangju 500-757, Korea. jongun@chonnam.ac.kr
Jong-Un
JU
Lee
Sang-Woo
SW
Lee
Kyoung-Woong
KW
Kim
Chung-Han
CH
Yoon
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