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Li K, Qian J, Wang P, Wang C, Lu B, Tian X, Jin W, He X, Chen H, Zhang Y, Liu Y. Differential responses of encoding-amoA nitrifiers and nir denitrifiers in activated sludge to anatase and rutile TiO 2 nanoparticles: What is active functional guild in rate limiting step of nitrogen cycle? JOURNAL OF HAZARDOUS MATERIALS 2020; 384:121388. [PMID: 31668758 DOI: 10.1016/j.jhazmat.2019.121388] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/26/2019] [Accepted: 10/02/2019] [Indexed: 06/10/2023]
Abstract
The long-terms effects of different crystal-composition TiO2 nanoparticles (NPs) on nitrogen-cycle-related functional guilds in activated sludge remain unclear, especially under natural light irradiation. Accordingly, activated sludge was exposed to anatase TiO2-NPs (TiO2-A) and rutile TiO2-NPs (TiO2-R) for up to 45 days. With markedly (p < 0.05) reducing nitrification-/denitrification-enzymatic-activities and abundances of ammonia-oxidizing-microorganisms (AOMs) and nitrite-reducing-bacteria (NRB), TiO2-NPs triggered bacteria and archaea UPGMA clustering and a deep modification of N-cycling functional diversity guided by crystal structure. in situ13C-DNA-SIP confirmed ammonia-oxidizing-bacteria (AOB) (Nitrosomonas and Nitrosospira) in original sludge as main active AOMs with 75.4 times more abundance than ammonia-oxidizing-archaea (AOA), while AOA within Nitrosopumilus and Nitrososphaera genera were the main active AOMs and tended to aggregate inside sludge after 10-mg/L TiO2-NPs exposure. Encoding-nirK NRB were more sensitive, while encoding-nirS Zoogloea with a total share of 4.97% to 14.93%, etc. were the main active NRB. AOB was more sensitive to TiO2-A, while TiO2-R showed the stronger toxicity to AOA and NRB resulting from differences in water environmental behaviors and crystal characteristics of two TiO2-NPs. This work expands understanding of the ecological risks of titanium-dioxide-crystal-NPs in aquatic environment and may help devise better methods to alleviate environmental stress caused by NPs at wastewater treatment plants.
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Affiliation(s)
- Kun Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Jin Qian
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
| | - Chao Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Bianhe Lu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Xin Tian
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Wen Jin
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Xixian He
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Hao Chen
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Yuhang Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Yin Liu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
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Xu ML, Zhu YG, Gu KH, Zhu JG, Yin Y, Ji R, Du WC, Guo HY. Transcriptome Reveals the Rice Response to Elevated Free Air CO 2 Concentration and TiO 2 Nanoparticles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:11714-11724. [PMID: 31509697 DOI: 10.1021/acs.est.9b02182] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Increasing CO2 levels are speculated to change the effects of engineered nanomaterials in soil and on plant growth. How plants will respond to a combination of elevated CO2 and nanomaterials stress has rarely been investigated, and the underlying mechanism remains largely unknown. Here, we conducted a field experiment to investigate the rice (Oryza sativa L. cv. IIyou) response to TiO2 nanoparticles (nano-TiO2, 0 and 200 mg kg-1) using a free-air CO2 enrichment system with different CO2 levels (ambient ∼370 μmol mol-1 and elevated ∼570 μmol mol-1). The results showed that elevated CO2 or nano-TiO2 alone did not significantly affect rice chlorophyll content and antioxidant enzyme activities. However, in the presence of nano-TiO2, elevated CO2 significantly enhanced the rice height, shoot biomass, and panicle biomass (by 9.4%, 12.8%, and 15.8%, respectively). Furthermore, the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that genes involved in photosynthesis were up-regulated while most genes associated with secondary metabolite biosynthesis were down-regulated in combination-treated rice. This indicated that elevated CO2 and nano-TiO2 might stimulate rice growth by adjusting resource allocation between photosynthesis and metabolism. This study provides novel insights into rice responses to increasing contamination under climate change.
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Affiliation(s)
- Mei-Ling Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Yong-Guan Zhu
- Key Lab of Urban Environment and Health, Institute of Urban Environment , Chinese Academy of Science , Xiamen 361021 , China
- State Key Lab of Urban and Regional Ecology, Research Center for Eco-environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
| | - Kai-Hua Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Jian-Guo Zhu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science , Chinese Academy of Science , Nanjing 210008 , China
| | - Ying Yin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Rong Ji
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Wen-Chao Du
- School of Environment , Nanjing Normal University , Nanjing 210023 , China
| | - Hong-Yan Guo
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
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Wang Z, Song Y, Cai X, Zhang J, Tang T, Wen S. Rapid preparation of terbium-doped titanium dioxide nanoparticles and their enhanced photocatalytic performance. ROYAL SOCIETY OPEN SCIENCE 2019; 6:191077. [PMID: 31824714 PMCID: PMC6837207 DOI: 10.1098/rsos.191077] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 09/02/2019] [Indexed: 06/10/2023]
Abstract
Further applications of photocatalysis were limited by the high recombination probability of photo-induced electron-hole pairs in traditional titanium dioxide nanoparticles (TiO2 NPs). Herein, we modified them with rare earth metal via a facile sol-gel method, using tetrabutyl titanate as a precursor and terbium (III) nitrate hexahydrate as terbium (Tb) source. The resulting samples with different Tb doping amounts (from 0 to 2%) have been characterized by X-ray diffraction, UV-visible diffuse reflectance spectroscopy, X-ray photo-electron spectroscopy and a scanning electron microscope. The photocatalytic performance of Tb-doped TiO2 was evaluated by the degradation of methylene blue. The effects of Tb doping amount and initial pH value of solution were investigated in detail. The composite with Tb doping amount of 1.0 wt% showed the highest photocatalytic performance. It exhibited approximately three times enhancement in photocatalytic activity with a reaction rate constant of 0.2314 h-1 when compared with that of commercial P25 (0.0827 h-1). In addition, it presented low toxicity on zebrafishes with 96 h-LC50 of 23.2 mg l-1, and has been proved to be reusable for at least four cycles without significant loss of photocatalytic activity. A probable photocatalytic mechanism of Tb-doped TiO2 was proposed according to the active species trapping experiments. The high photocatalytic performance, excellent reusability and low toxicity of Tb-doped TiO2 indicated that it is a promising candidate material in the future treatment of dye wastewater.
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Affiliation(s)
- Zhencui Wang
- Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, Hainan 571199, People's Republic of China
- Laboratory of Environmental Monitoring, College of Tropical and Laboratory Medicine, Hainan Medical University, Haikou 571101, People's Republic of China
| | - Yuechao Song
- Laboratory of Environmental Monitoring, College of Tropical and Laboratory Medicine, Hainan Medical University, Haikou 571101, People's Republic of China
| | - Xingfei Cai
- Guangdong Tianyuan Environment Co., Ltd, Shenzhen 578061, People's Republic of China
| | - Jun Zhang
- Laboratory of Environmental Monitoring, College of Tropical and Laboratory Medicine, Hainan Medical University, Haikou 571101, People's Republic of China
| | - Tianle Tang
- Laboratory of Environmental Monitoring, College of Tropical and Laboratory Medicine, Hainan Medical University, Haikou 571101, People's Republic of China
| | - Shaobai Wen
- Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, Hainan 571199, People's Republic of China
- Laboratory of Environmental Monitoring, College of Tropical and Laboratory Medicine, Hainan Medical University, Haikou 571101, People's Republic of China
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