Arsenite oxidation in batch reactors with alginate‐immobilized ULPAs1 strain

Arsenic is one of the major groundwater contaminants worldwide. It was previously demonstrated that the β‐proteobacterium Cenibacterium arsenoxidans has an efficient As[III] oxidation ability. The present study was conducted to evaluate the performance of alginate‐immobilized ULPAs1 in the oxidation of As[III] to As[V] in batch reactors. A two‐level full factorial experimental design was applied to investigate the influence of main parameters involved in the oxidation process, i.e., pH (7–8), temperature (4°C–25°C), kind of nutrient media (2%–20% sauerkraut brine), and arsenic concentration (10–100 mg/L). One hundred milligram per liter of As[III] was fully oxidized by calcium‐alginate immobilized cells in 1 h. It was found that the temperature as well as the kind of nutrient media used were significant parameters at a 95% confidence interval whereas only temperature was a significant parameter at a 99% confidence interval. The immobilization of the As[III] oxidizing strain in alginate beads offers a promising way to implement new treatment processes in the remediation of arsenic contaminated waters. © 2005 Wiley Periodicals, Inc.