Anaerobic Biodegradation of PAH in River Sediment Treated with Different Additives

Abstract

Abstract Excavation of the polluted sediments is a remediation approach for the polluted rivers and streams, when the excavated sediments can be reasonably detoxified. In this work, PAHs in river sediments was removed by mixing with different additives such as acetate, lactate, and spent mushroom compost (SMC), to test the ability of indigenous microorganisms on anaerobic PAH degradation. The activities of dehydrogenase and polyphenol oxidase were also investigated. 9% of phenanthrene and no anthracene in the river sediments can be degraded naturally in 30 days and increased to 22% and 53%, 28% and 63%, 44% and 53% in the presence of 40 mM/kg acetate, 40 mM/kg lactate and 10% SMC, respectively. The dehydrogenase activities increased remarkably from 23 to 225, 456 and 920 mg triphenylformazan/kg/24hr in sediments amended with acetate, lactate and SMC respectively. The results supported that readily degradable carbon sources boost PAH anaerobic biodegradation dramatically. SMC is recommended as a potential amendment for intrinsic anaerobic biodegradation of PAH in polluted river sediments.