X. Zhang’s scientific contributions

In order to investigate the change of disinfection by-product (DBP) precursors during the sewage treatment process, dissolved organic matter (DOM) of the effluents during the AAO-MBR process was separated with ultrafiltration membrane and XAD adsorption resin, then characterized with 3D-EEM spectra. The DBPFP of effluents and their separated fractions were further evaluated in this study. The results showed that C-DBPFP of the grit chamber effluent was low, the AAO and MBR processes could increase C-DBPFP significantly. SMPs produced by microbial metabolism during the AAO and MBR processes was the major C-DBP precursors. The grit chamber effluent also displayed low N-DBPFP. The AAO process led to the increase in N-DBPFP mainly due to the production of small molecule SMPs. The MBR process could result in the decrease in N-DBPFP comparing to the AAO process, by reducing small molecule SMPs with long SRT and high sludge concentration. In all, the AAO process would obviously enhance C-DBP and N-DBP precursors by 90.9% and 7.3%, respectively. However, the MBR process could remove 74.4% DOC, resulting in 56.8% C-DBP precursor and 78.1% N-DBP precursor removal. Therefore, AAO-MBR had a respectable removal effect on C and N-DBPs precursors in the municipal sewage. © 2018, Editorial Board, Research of Environmental Sciences. All right reserved.