文献类型：期刊文献

英文题名：Achieving enhanced denitrification via hydrocyclone treatment on mixed liquor recirculation in the anoxic/aerobic process

作者：Liu, Yi[1];Wang, Hualin[1];Xu, Yinxiang[2];Tu, Qingsong[3];Chen, Xiurong[4]

机构：[1]East China Univ Sci & Technol, Natl Engn Lab Ind Wastewater Treatment, Shanghai 200237, Peoples R China;[2]Sichuan Univ Sci & Engn, Coll Mech Engn, Zigong 643000, Peoples R China;[3]Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA;[4]East China Univ Sci & Technol, Sch Resources & Environm Engn, Shanghai 200237, Peoples R China

年份：2017

卷号：189

起止页码：206

外文期刊名：CHEMOSPHERE

收录：;EI(收录号：20173804186236);WOS:【SCI-EXPANDED(收录号:WOS:000414817900023)】；

基金：We would like to express our thanks for the sponsorship from the National Science Foundation for Distinguished Young Scholars of China (Grant No. 51125032). Yi Liu is grateful for the support of the visiting scholar program from the Chinese Scholar Council (CSC).

语种：英文

外文关键词：Hydrocyclone; Sludge disruption; Enzyme activity; Denitrification

摘要：This work presents the novel application of hydrocyclones for mixed liquor recirculation (MLR) treatment in the anoxic/aerobic (A/O) process to enhance the denitrification process. An exhaustive investigation on treated activated sludge and A/O effluents was conducted in batch and continuous operation tests. The median diameter of the sludge flocs was decreased from 78.82 mu m to 15.77-23.31 mu m, and the extracellular polymeric substances (EPS) desorption was observed, thus leading to the release of the soluble chemical oxygen demand (SCOD). A marked increase in the BOD5/TN ratio was consequently achieved, which supplied the carbon source and improved the biodegradability of the MLR. The hydrocyclone treatment also enabled a 7.17% +/- 0.93% specific oxygen utilization rate (SOUR) increase at the optimal hydrocyclone intensity of 0.13 MPa, owing to the desorption of positioned microbial secretion from the microorganism cells. The nitrate reductase and nitrite reductase were also improved by 15.13% +/- 1.16% and 17.61% +/- 1.55%, respectively. The nitrate removal efficiency was enhanced by 13.6%, and the nitrogen oxide gases varied slightly; this behavior was consistent with the variations in the key enzymes involved in denitrification. The A/O process operated in the mode of hydrocyclone-treated MLR, compared with in the conventional mode, resulted in a 15.56% higher TN removal, and the other effluent parameters remained stable. Hydrocyclone disruption is thus a convenient and energy-efficient process with broad implications in denitrification development. (C) 2017 Elsevier Ltd. All rights reserved.