Biodegradation of di-n-butyl phthalate in sequencing batch reactor bioaugmented with Micrococcus sp and the bacterial community analysis

Di-n-butyl phthalate is widely used as plasticizer, which has been listed as priority pollutant due to its toxic and ubiquitous characteristics. It is difficult to remove by the conventional wastewater treatment processes. In this paper, the feasibility of using Micrococcus sp. to bioaugment a sequencing batch reactor for degrading di-n-butyl phthalate (DBP) was investigated. The terminal restriction fragment length polymorphisms (T-RFLP) were used to analyze the variation of microbial community in the reactor. The experimental results showed that for the bioaugmented reactor, the removal efficiency of DBP was about 85 % as compared to 25 % of the control reactor when initial DBP concentration was 100 mg/L. The bioaugmentation not only enhanced the removal efficiency of target compound, but also shortened the start-up time of the reactor. The kinetics of DBP degradation conformed to the first-order model in both reactors. The T-RFLP analysis indicated the bacterial community changes in the acclimated activated sludge and the introduced Micrococcus sp. during the operational process.