Exploring the essential factors of performance improvement in sludge membrane bioreactor technology coupled with symbiotic algae

Li Sun; Jinxing Ma; Lipin Li; Yu Tian; Zhong Zhang; Huaiyu Liao; Jibin Li; Wangwang Tang; Di He

doi:10.1016/j.watres.2020.115843

Exploring the essential factors of performance improvement in sludge membrane bioreactor technology coupled with symbiotic algae

Water Res. 2020 Aug 15:181:115843. doi: 10.1016/j.watres.2020.115843. Epub 2020 May 10.

Authors

Li Sun¹, Jinxing Ma², Lipin Li³, Yu Tian³, Zhong Zhang⁴, Huaiyu Liao⁴, Jibin Li⁴, Wangwang Tang⁵, Di He⁶

Affiliations

¹ Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China; State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
² Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia.
³ State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
⁴ Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
⁵ College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha, 410082, China.
⁶ Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China. Electronic address: di.he@gdut.edu.cn.

PMID: 32422450
DOI: 10.1016/j.watres.2020.115843

Abstract

In this study, a coupled system of algal-sludge and membrane bioreactor (AS-MBR) was established for fouling control, and meanwhile the performance of wastewater treatment was enhanced. Results indicated that the AS-MBR increased the COD, NH₄⁺-N, TN and PO₄^3- -P removal efficiencies from 91.7% to 95.9%, 90.8%-96.9%, 22.0% to 34.3% and 18.4%-32.6%, respectively. Further analysis suggested that in the AS-MBR, the total specific oxygen utilization rate (SOUR), the SOUR of ammonia oxidizing bacteria and the SOUR of nitrite oxidizing bacteria were 26.6%, 58.5% and 52.4% higher than the control, respectively, indicating the improvement of microbial activities in AS-MBR. Additionally, the membrane fouling rates in the AS-MBR were 52.6% and 32.2% lower than the control in the slow and rapid fouling processes, respectively. A further mechanism investigation demonstrated that the concentrations of extracellular polymeric substance (EPS) were decreased by 19.8% and 22.1% in the mixed liquid and the fouling layer, respectively, after the inoculation of algae, which was expected to have a positive effect on the higher permeability and longer operation cycle of the membrane in the AS-MBR. More regular floc morphology was observed for the fouling layer on the membrane of AS-MBR, with the polysaccharides and proteins forming large clusters and channels in the fouling layer that likely decreased the filtration resistance. Consequently, high-throughput sequencing analysis revealed that the microbial community in the AS-MBR had higher abundances of bacteria and algae related to nutrients and organic matters degradation, which was beneficial for the improvement of wastewater treatment and alleviation of membrane fouling.

Keywords: Algal-sludge membrane bioreactor; Extracellular polymeric substances; Fouling; Microbial community.

MeSH terms

Bioreactors
Extracellular Polymeric Substance Matrix*
Membranes, Artificial
Sewage*
Wastewater

Substances

Membranes, Artificial
Sewage
Waste Water