Comparison of the effects and distribution of zinc oxide nanoparticles and zinc ions in activated sludge reactors

Zhang, Dongqing and Trzcinski, Antoine and Oh, Hyun-Suk and Chew, Evelyn and Liu, Yu and Tan, Soon Keat and Ng, Wun Jern (2017) Comparison of the effects and distribution of zinc oxide nanoparticles and zinc ions in activated sludge reactors. Journal of Environmental Science and Health, Part A: Toxic Hazardous Substances and Environmental Engineering, 52 (11). pp. 1073-1081. ISSN 1093-4529

Abstract

Zinc Oxide nanoparticles (ZnO NPs) are being increasingly applied in the industry, which results inevitably in the release of these materials into the hydrosphere. In this study, simulated waste-activated sludge experiments were conducted to investigate the effects of Zinc Oxide NPs and to compare it with its ionic counterpart (as ZnSO4). It was found that even 1 mg/L of ZnO NPs could have a small impact on COD and ammonia removal. Under 1, 10 and 50 mg/L of ZnO NP exposure, the Chemical Oxygen Demand (COD) removal efficiencies decreased from 79.8% to 78.9%, 72.7% and 65.7%, respectively. The corresponding ammonium (NH4 C N) concentration in the effluent significantly (P < 0.05) increased from 11.9 mg/L (control) to 15.3, 20.9 and 28.5 mg/L, respectively. Under equal Zn concentration, zinc ions were more toxic towards microorganisms compared to ZnO NPs. Under 50 mg/L exposure, the effluent Zn level was 5.69 mg/L, implying that ZnO NPs have a strong affinity for activated sludge. The capacity for adsorption of ZnO NPs onto activated sludge was found to be 2.3, 6.3, and 13.9 mg/g MLSS at influent ZnO NP concentrations of 1.0, 10 and 50 mg/L respectively, which were 1.74-, 2.13- and 2.05-fold more than under Zn ion exposure.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying
Date Deposited: 11 Dec 2017 05:08
Last Modified: 01 Feb 2018 02:23
Uncontrolled Keywords: biosorption; waste activated sludge; zinc ions; ZnO nanoparticles
Fields of Research : 09 Engineering > 0904 Chemical Engineering > 090409 Wastewater Treatment Processes
09 Engineering > 0907 Environmental Engineering > 090703 Environmental Technologies
05 Environmental Sciences > 0502 Environmental Science and Management > 050205 Environmental Management
Socio-Economic Objective: D Environment > 96 Environment > 9609 Land and Water Management > 960912 Urban and Industrial Water Management
Identification Number or DOI: 10.1080/10934529.2017.1338896
URI: http://eprints.usq.edu.au/id/eprint/33034

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