title: Long-term effects of nickel oxide nanoparticles on performance, microbial enzymatic activity, and microbial community of a sequencing batch reactor.
abstract: The nitrogen and phosphorus removal, microbial enzymatic activity, and microbial community of a sequencing batch reactor (SBR) were evaluated under long-term exposure to nickel oxide nanoparticles (NiO NPs). High NiO NP concentration (over 5 mg L-1) affected the removal of chemical oxygen demand, nitrogen, and phosphorus. The presence of NiO NP inhibited the microbial enzymatic activities and reduced the nitrogen and phosphorus removal rates of activated sludge. The microbial enzymatic activities of the activated sludge showed a similar variation trend to the nitrogen and phosphorus removal rates with the increase in NiO NP concentration from 0 to 60 mg L-1. The Ni content in the effluent and activated sludge showed an increasing trend with the increase in NiO NP concentration. Some NiO NPs were absorbed on the sludge surface or penetrate the cell membrane into the interior of microbial cells in the activated sludge. NiO NP facilitated the increase in reactive oxygen species by disturbing the balance between the oxidation and anti-oxidation processes, and the variation in lactate dehydrogenase demonstrated that NiO NP could destroy the cytomembrane and cause variations in the microbial morphology and physiological function. High-throughput sequencing demonstrated that the microbial community of SBR had some obvious changes at 0-60 mg L-1NiO NPs at the phyla, class and genus levels.
authors.affiliation: Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China; School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China; Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Sen
authors.initials: S
authors.lastname: Wang
authors.affiliation: Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Li
authors.affiliation: Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Qingdao 266100, China. Electronic address: mengchungao@outlook.com.
authors.forename: Mengchun
authors.initials: M
authors.lastname: Gao
authors.affiliation: Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
authors.forename: Zonglian
authors.initials: Z
authors.lastname: She
authors.affiliation: Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Guo
authors.affiliation: Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zheng
authors.affiliation: Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
authors.forename: Yangguo
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Bingrui
authors.initials: B
authors.lastname: Ma
authors.affiliation: Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.affiliation: Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
authors.forename: Xuejiao
authors.initials: X
authors.lastname: Wang
mesh_terms: D001419:Bacteria / Q000145:classification / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry*; D059013:Microbial Consortia; D009532:Nickel / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000378:metabolism; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid
chemical_list: D017382:Reactive Oxygen Species; D012722:Sewage; D010758:Phosphorus; D009532:Nickel; C028007:nickel monoxide; D007770:L-Lactate Dehydrogenase; D009584:Nitrogen; D010100:Oxygen
keywords: Activated sludge; LDH; Microbial diversity and richness; Microbial enzymatic activity; NiO NPs; ROS