Desorption and degradation of fenobucarb in paddy soil with the presence of pH, dissolved organic carbon, and sodium dodecyl sulphate in irrigation water

Abstract

The presence of pH, dissolved organic carbon (DOC), and sodium dodecyl sulphate (SDS) in irrigation water for rice fields enhanced the release and biodegradation of fenobucarb in the soil-water system, contributing to the diminishing of fenobucarb and 2-sec-butylphenol in the soil and drain water. The fenobucarb-spiked soil was amended with pH 7, pH 9, 25 mg L− 1 DOC, and 1 critical micelle (2.4 g L− 1) SDS solutions, and the residual fenobucarb and 2-sec-butyl phenol were analysed in water and soil after each decomposition period. The disappearance of fenobucarb and the appearance of 2-sec-butylphenol were the result of biodegradation and hydrolysis, and these processes were influenced by the presence in the order of pH 9, DOC, pH 7, and SDS. In the presence of SDS in the solution, the desorption and biodegradation processes simultaneously affected the degradation of fenobucarb in the soil. However, fenobucarb biodegradation was inhibited, probably because of the preferential utilisation of SDS by fenobucarb degraders.