Powdered activated carbon - Membrane bioreactor (PAC-MBR): Impacts of high PAC concentration on micropollutant removal and microbial communities

Muhammad Bilal Asif; Baoyu Ren; Chengyue Li; Tahir Maqbool; Xihui Zhang; Zhenghua Zhang

doi:10.1016/j.scitotenv.2020.141090

Powdered activated carbon - Membrane bioreactor (PAC-MBR): Impacts of high PAC concentration on micropollutant removal and microbial communities

Sci Total Environ. 2020 Nov 25:745:141090. doi: 10.1016/j.scitotenv.2020.141090. Epub 2020 Jul 23.

Authors

Muhammad Bilal Asif¹, Baoyu Ren¹, Chengyue Li¹, Tahir Maqbool¹, Xihui Zhang¹, Zhenghua Zhang²

Affiliations

¹ Institute of Environmental Engineering & Nano-Technology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China; Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China; School of Environment, Tsinghua University, Beijing 100084, China.
² Institute of Environmental Engineering & Nano-Technology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China; Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China; School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: zhenghua.zhang@sz.tsinghua.edu.cn.

PMID: 32758744
DOI: 10.1016/j.scitotenv.2020.141090

Abstract

In this study, the effect of a high concentration of powdered activated carbon (PAC) on pollutant removal and microbial communities was systematically investigated. Micropollutant removal by the 'control' MBR (without PAC addition) was pollutant-specific and was mainly controlled by their molecular properties. The PAC-MBR achieved enhanced removal of micropollutant by 10% (ofloxacin) to 40% (caffeine). Analysis of the microbial communities in the sludge samples collected from both MBRs indicated an increase in the abundance of 24 (out of 31) genera following PAC addition. Notably, bacterial diversity enriched, particularly in the anoxic zone of the PAC-MBR, indicating a positive impact of recirculating mixed liquor containing PAC from the aerobic to the anoxic zone. In addition, PAC improved the abundance of Comamonas and Methanomethylovorans (up to 2.5%) that can degrade recalcitrant micropollutants. According to the quantitative PCR (qPCR) analysis, the copies of functional genes (nirS, nosZ and narG) increased in PAC-MBR. This study demonstrated that MBR could be operated at a high PAC concentration without compromising the pollutant removal and microbial community evolution during wastewater treatment.

Keywords: Functional genes; Membrane bioreactor (MBR); Microbial communities; Micropollutants; Powdered activated carbon (PAC).

MeSH terms

Bioreactors
Charcoal*
Membranes, Artificial
Microbiota*
Powders
Sewage
Waste Disposal, Fluid

Substances

Membranes, Artificial
Powders
Sewage
Charcoal