Re-evaluation of the environmental hazards of nZnO to denitrification: Performance and mechanism
| Autor: | Yang-Yang Fan, Xiang Xiao, Feng-Ting Cao, Xiangtong Zhou, Xiao-Lin Ma, En-Jing He |
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| Rok vydání: | 2021 |
| Předmět: |
Environmental Engineering
Denitrification Nitrogen Health Toxicology and Mutagenesis Nanoparticle chemistry.chemical_element Zinc Wastewater Anaerobic Ammonia Oxidation Denitrifying bacteria Biotreatment Bioreactors Environmental Chemistry Inhibitory effect Sewage Chemistry Public Health Environmental and Occupational Health General Medicine General Chemistry Pollution Anammox Environmental chemistry Nanoparticles Oxidation-Reduction |
| Zdroj: | Chemosphere. 291(Pt 2) |
| ISSN: | 1879-1298 |
| Popis: | Numerous studies have shown that zinc oxide nanoparticles (nZnO) have an inhibitory effect on wastewater biotreatment, where doses exceeding ambient concentrations are used. However, the effect of ambient concentrations of ZnO (1 mg/L) on anaerobic digestion processes is not clear. Herein, this study comprehensively explored the impact of nZnO on the denitrification performance and core microbial community of activated sludge under ambient concentrations. Results showed that only 0.075 mg/L nZnO had shown a beneficial effect on nitrogen removal by activated sludge. When nZnO concentration reached 0.75 mg/L, significant enhancement of nitrate reduction and mitigation of nitrite accumulation were observed, indicating a remarkable stimulatory effect on nitrogen removal. Simultaneously, nZnO could weaken the sludge surface charge and improve the secretion of extracellular polymeric substances, thus enhancing sludge flocculation for denitrification. Microbial community analysis revealed that nZnO exposure increased the relative abundance of denitrifying bacteria, which could contribute to the reinforcement of traditional denitrification. Furthermore, exogenous addition of NH |
| Databáze: | OpenAIRE |
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