title: Insight into the impact of ZnO nanoparticles on aerobic granular sludge under shock loading.
abstract: The increasing use of zinc oxide nanoparticles (ZnO NPs) has raised concerns about the environmental threats to the wastewater treatment systems. Shock loading of 10, 50 and 100 mg/L ZnO NPs was conducted to evaluate impacts on reactor performance, microbial activities and extracellular polymeric substances (EPS) in parent aerobic/oxic/anoxic (A/O/A) granular sequencing batch reactors (SBRs). The results showed that ZnO NPs caused inhibition to nitrogen transformations due to acute toxicity to nitrification and denitrification. However, phosphorus removal remained unaffected by the exposure to ZnO NPs. Besides, ZnO NPs significantly enhanced the oxygen respiration rate and caused acute toxicity to ammonia oxidizing rate (10.40-35.21%), phosphorus release rate (37.79-19.80%), aerobic phosphorus uptake rate (36.95-20.69%) and total phosphorus uptake rate (32.77-16.91%) of aerobic granules. ZnO NPs stimulated the secretion of EPS, especially the content of protein (PN), which could relieve the toxicity of ZnO NPs.
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China.
authors.forename: Qiulai
authors.initials: Q
authors.lastname: He
authors.affiliation: School of Food Science and Engineering, Guangzhou 510640, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Yuan
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China.
authors.forename: Shilu
authors.initials: S
authors.lastname: Zhang
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China.
authors.forename: Zhuocheng
authors.initials: Z
authors.lastname: Zou
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China. Electronic address: hywang96@126.com.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Wang
mesh_terms: D000332:Aerobiosis; D000641:Ammonia / Q000378:metabolism; D001704:Biopolymers / Q000096:biosynthesis; D019149:Bioreactors; D058440:Denitrification; D053768:Metal Nanoparticles / Q000633:toxicity*; D058465:Nitrification; D009584:Nitrogen / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000379:methods*; D015034:Zinc Oxide / Q000633:toxicity*
chemical_list: D001704:Biopolymers; D012722:Sewage; D010758:Phosphorus; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen; D015034:Zinc Oxide
keywords: A/O/A SBR; AGS; Biological nitrogen and phosphorus removal; Environmental impact; ZnO NPs