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Wang Q, Zheng W, Wang Y, Zhang T, Zhou Z, Wu Z. Insights into effects of operating temperature on the removal of pharmaceuticals/pesticides/synthetic organic compounds by membrane bioreactor process. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 335:122145. [PMID: 37422084 DOI: 10.1016/j.envpol.2023.122145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/17/2023] [Accepted: 07/03/2023] [Indexed: 07/10/2023]
Abstract
In this study, the removal efficiency and mechanism of 8 kinds of typical micropollutants by membrane bioreactor (MBR) at different temperatures (i.e. 15, 25 and 35 °C) were investigated. MBR exhibited the high removal rate (>85%) for 3 kinds of industrial synthetic organic micropollutants (i.e. bisphenol A (BPA), 4-tert-octylphenol (TB) and 4-n-nonylphenol (NP)) with similar functional groups, structures and high hydrophobicity (Log D > 3.2). However, the removal rates of ibuprofen (IBU), carbamazepine (CBZ) and sulfamethoxazole (SMX) with pharmaceutical activity showed great discrepancy (i.e. 93%, 14.2% and 29%, respectively), while that of pesticides (i.e. acetochlor (Ac) and 2,4-dichlorophenoxy acetic acid (2,4-D) were both lower than 10%. The results showed that the operating temperature played a significant role in microbial growth and activities. High temperature (35 °C) led to a decreased removal efficiency for most of hydrophobic organic micropollutants, and was also not conducive for refractory CBZ due to the temperature sensitivity. At lower temperature (15 °C), a large amount of exopolysaccharides and proteins were released by microorganisms, which caused the inhibited microbial activity, poor flocculation and sedimentation, resulting in the polysaccharide-type membrane fouling. It was proved that dominant microbial degradation of 61.01%-92.73% and auxiliary adsorption of 5.29%-28.30% were the main mechanisms for micropollutant removal in MBR system except for pesticides due to the toxicity. Therefore, the removal rates of most micropollutants were highest at 25 °C due to the high activity sludge so as to enhance microbial adsorption and degradation.
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Affiliation(s)
- Qiaoying Wang
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Wenjia Zheng
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Yan Wang
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Tong Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
| | - Zhen Zhou
- College of Environmental and Chemical Engineering, Shanghai Institute of Pollution Control and Ecological Security, Shanghai University of Electric Power, Shanghai, 200090, China
| | - Zhichao Wu
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
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The Municipal Sewage Discharge May Impact the Dissemination of Antibiotic-Resistant Escherichia coli in an Urban Coastal Beach. WATER 2022. [DOI: 10.3390/w14101639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
To determine the potential of the recreational marine environment as a dissemination vector of antibiotic-resistant microorganisms, the dissemination of antibiotic-resistant E. coli strains isolated from an urban coastal beach was studied. Sixty-nine and thirteen E. coli strains were isolated from the seawater and sand, respectively, in Fujiazhuang bathing beach, China. The average Antibacterial Resistance Index (ARI) value detected in the seawater is approximately three times that in beach sand. All the isolates from the sand were grouped into one cluster and only the isolates from the municipal sewage outlet were classified into three antibiogram clusters that were observed in the hetero-sites of the E. coli isolates. The E. coli strains with multiple antibiotic resistance (58% of total) were prevalent in the seawater, whereas the isolates from the sand were not detected with multiple antibiotic resistance. A significant association (p < 0.05) between all phenotypic and relative genotypic resistance profiles was observed in the isolates, except in the quinolones resistance genotype. The presence of a class 1 integron was significantly correlated with the resistance of E. coli to sulfonamides, streptomycin, and levofloxacin (p < 0.01). This study revealed that the municipal sewage discharge may impact the dissemination of antibiotic-resistant strains in the urban coastal beach, and that the class 1 integrons play an important role in mediating the resistance of E. coli to sulfonamide antibiotics.
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