BIODEGRADATION OF PHTHALIC-ACID ESTERS BY ACCLIMATED ACTIVATED-SLUDGE

The microbial degradation by acclimated activated sludge of three phth alates, priority pollutants listed by both the China National Environm ental Monitoring Centre and the U.S. EPA, i.e., dimethyl (DMP), di-n-b utyl (DBP), and di-n-octyl (DOP) phthalate was investigated. The exper imental results demonstrated that DMP and DBP with the shorter alkyl-s ide chain phthalic acid esters (PAEs) can be rapidly degraded-nearly 9 0% within 3 d for DMP and 8 d for DBP. However, the degradation rate o f DOP was slow. The degradation of PAEs can be described by the first- order reaction model. The first-order rate constants (k(l)) of three P AEs determined in this study can correlate with the corresponding seco nd-order hydrolysis rate constants (k(OH)). Copyright (C) 1996 Elsevie r Science Ltd