Biodegradation and detoxification of wood leachate from pentachlorophenol‐treated poles

Abstract

AbstractThe pentachlorophenol (PCP) in leachate, generated from size‐reduced PCP‐treated poles, was degraded using a mixed culture containing Arthrobacter sp. in cyclic batch bioreactors in non‐sterile conditions. Complete degradation of PCP was achieved for a five‐month period for a concentration of 50 mg PCP/L and 12 h cycle time. The adsorbable organic halogen (AOX) concentration of the reactor effluent was reduced by two orders of magnitude compared to the feed, and the chemical oxygen demand (COD) was reduced by 50%. The increase in chloride ion concentration also suggests that PCP was mineralized to end products. In tests to increase the process throughput, complete degradation of PCP was also achieved in the cases for 120 mg PCP/L and a 12 h cycle time or 50 mg PCP/L and a 6 h cycle time. Daphnia magna toxicity tests showed that the presence of PCP in leachate caused toxicity, and the biodegradation of PCP resulted in significantly reducing the effluent toxicity to a value similar to that of PCP‐free nutrient solution.