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Mu M, Li D, Lin S, Bi H, Liu X, Wang Z, Qian C, Ji J. Insights into the individual and combined effects of Cu(Ⅱ) and Ni(Ⅱ) on anammox: Nitrogen removal performance, enzyme activity and microbial community. CHEMOSPHERE 2024; 365:143308. [PMID: 39265735 DOI: 10.1016/j.chemosphere.2024.143308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2024] [Revised: 09/03/2024] [Accepted: 09/09/2024] [Indexed: 09/14/2024]
Abstract
Anaerobic ammonium oxidation (anammox) is an efficient and economical nitrogen removal process for treating ammonium-rich industrial wastewaters. However, Cu(Ⅱ) and Ni(Ⅱ) present in industrial wastewaters are toxic to anaerobic ammonium-oxidizing bacteria (AnAOB). Unfortunately, the effects of Cu(Ⅱ) and Ni(Ⅱ) on anammox have not been thoroughly investigated, especially when Cu(Ⅱ) and Ni(Ⅱ) coexist. This work comprehensively investigated the individual and combined effects of Cu(Ⅱ) and Ni(Ⅱ) on anammox and revealed the inhibitory mechanisms. With the influent NH4+-N and NO2--N concentration of 230 and 250 mg L-1, the inhibition thresholds on anammox are 2.00 mg L-1 Cu(Ⅱ), 1.00 mg L-1 Ni(Ⅱ) and 1.00 mg L-1 Cu(Ⅱ) + 1.00 mg L-1 Ni(Ⅱ), and higher Cu(Ⅱ) or Ni(Ⅱ) concentrations resulted in sharp deteriorations of nitrogen removal performance. The inhibition of Ni(Ⅱ) on anammox was mainly attributed to the adverse effect on NiR activity, while the inhibition mechanism of Cu(Ⅱ) seemed to be unrelated to the four functional enzymes, but associated with disruption of cellular and organellar membranes. The behavior of extracellular polymeric substances (EPS) contributed to the antagonistic effect between Cu(Ⅱ) and Ni(Ⅱ) on anammox. In addition, the niche of Candidatus Brocadia and Candidatus Jettenia shifted under the Cu(II) and Ni(II) stress, and Candidatus Jettenia displayed greater tolerance to Cu(II) and Ni(II) stress. In conclusion, this research clarified the combined effect and the inhibitory mechanism of multiple heavy metals on anammox, and provide the guidances for anammox process application in treating high-ammonium industrial wastewaters containing heavy metals.
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Affiliation(s)
- Minghao Mu
- Innovation Research Institute, Shandong Hi-speed Group, Jinan, 250001, China
| | - Dengzhi Li
- Key Lab of Marine Environment and Ecology of Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Shilin Lin
- Key Lab of Marine Environment and Ecology of Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Haisong Bi
- Innovation Research Institute, Shandong Hi-speed Group, Jinan, 250001, China
| | - Xinqiang Liu
- Innovation Research Institute, Shandong Hi-speed Group, Jinan, 250001, China
| | - Zheng Wang
- Innovation Research Institute, Shandong Hi-speed Group, Jinan, 250001, China
| | - Chengduo Qian
- Innovation Research Institute, Shandong Hi-speed Group, Jinan, 250001, China
| | - Junyuan Ji
- Key Lab of Marine Environment and Ecology of Ministry of Education, Ocean University of China, Qingdao, 266100, China.
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Cheng J, Qiao L, Xu W, Qian Y, Ge Y, Xia T, Li Y. Nickel (ii) effects on Anammox reaction: reactor performance, dehydrogenase, sludge morphology and microbial community changes. ENVIRONMENTAL TECHNOLOGY 2022; 43:4227-4236. [PMID: 34152252 DOI: 10.1080/09593330.2021.1946165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/13/2021] [Indexed: 06/13/2023]
Abstract
Nickel (ii) (Ni2+) is considered as one of the necessary trace elements in the process of Anammox culture, but it may have toxic effects at high concentration. This study explored the long-term influence of Ni2+ on the denitrification efficiency of Anammox bioreactors. The results showed that when the concentration of Ni2+ was 0.5 mg/L, the bioreactor had the highest denitrification efficiency, while the removal efficiency of ammonia nitrogen and nitrite nitrogen gradually decreased at concentrations higher than 2 mg/L, and the removal rates of ammonia nitrogen and nitrite nitrogen were 26% and 39.81% at the end of the experiment, respectively. The NRR was decreased from 7.47 kg N/m3 d to 3.28 kg N/m3 d during the whole process. The highest concentration of microbial dehydrogenase was attained in about 40 days; in the meantime, its ability to consume organic matter was also maximized. The sludge morphology was changed from granular cluster to loose flocculant with a small number of spherical and filamentous bacteria and bacilli distributed on the surface. At the end of the experiment, both species richness and community diversity were reduced, and the proportion of the dominant bacteria Candidatus Kuenenia was also decreased from 59.89% to 36.72%.
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Affiliation(s)
- Jian Cheng
- School of Environmental Science and Spatial Informatics, CUMT, Xuzhou, People's Republic of China
| | - Liang Qiao
- School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, People's Republic of China
| | - Wen Xu
- Everbright Water Technology Development (Nanjing) Co., Ltd., Nanjing, People's Republic of China
| | - Yulan Qian
- School of Environmental Science and Spatial Informatics, CUMT, Xuzhou, People's Republic of China
| | - Yiyang Ge
- School of Environmental Science and Spatial Informatics, CUMT, Xuzhou, People's Republic of China
| | - Ting Xia
- School of Environmental Science and Spatial Informatics, CUMT, Xuzhou, People's Republic of China
| | - Yan Li
- School of Environmental Science and Spatial Informatics, CUMT, Xuzhou, People's Republic of China
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Negi R, Kumar R, Jawed M. Recovery potential of aerobic sludge biomass from Co (II) stress in sequencing batch reactors. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:61954-61966. [PMID: 35378654 DOI: 10.1007/s11356-022-19965-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 03/25/2022] [Indexed: 06/14/2023]
Abstract
Heavy metals in higher concentrations are often encountered in domestic sewage of developing and under-developed countries. High metallic concentrations can stress reactor sludge biomass morphology impeding its performance in organics reduction. However, the extent of damage and ability of sludge biomass to recover from the metallic stress is not fully understood. Also, there is no protocol to identify and prevent the sludge biomass from metallic stress in fully functional sewage treatment plants (STPs). This study investigates performance, metabolic activity, morphology, and settling characteristics of the sludge biomass under different Co(II) stress conditions. The extent of recovery in biomass, when the supply of Co(II) metal ion was discontinued in the inlet stream, was explored. The study also proposed a protocol based on simple settling characteristics of sludge biomass to get an early indication of metal infiltration to prevent potential damage to the biomass morphology. Four sequencing batch reactors (SBRs) with Co(II) ion concentrations of 0 (designated as RCo0), 5 (RCo5), 25 (RCo25), and 75 mg/L (RCo75) in the feed were operated with a cycle time of 12 h. Reactors were operated for 35 days with Co(II) in the feed (termed as stressed phase operation) followed by 24 days of operation without Co(II) in the feed (termed as recovery phase operation). Results show that COD removal in reactor RCo75 reduced to 48% on the 10th day of stressed phase operation, showing a lag in COD removal due to metallic stress. The activity of biomass in reactors RCo5, RCo25, and RCo75 was reduced by 39%, 45%, and 49%, respectively, in the stressed phase compared to the biomass in control reactor. Recovery in COD removal efficiency and specific biomass activity were observed in all the reactors after the removal of metallic stress. The settleability of sludge biomass in reactors RCo25 and RCo75 was significantly affected. Transformation in the shape of flocs in reactor RCo25 and RCo75 biomasses revealed the prolonged effect of metallic stress, which was observed to be irreversible even during the recovery phase operation.
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Affiliation(s)
- Rajhans Negi
- Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
- Environmental Science and Engineering Department, Environmental Research Laboratory, Indian Institute of Technology Bombay, Mumbai, Maharashtra, 400076, India.
| | - Rajneesh Kumar
- Centre for the Environment, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Mohammad Jawed
- Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
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Syamimi Zaidi N, Syafiuddin A, Sillanpää M, Burhanuddin Bahrodin M, Zhang Zhan L, Ratnasari A, Kadier A, Aamer Mehmood M, Boopathy R. Insights into the potential application of magnetic field in controlling sludge bulking and foaming: A review. BIORESOURCE TECHNOLOGY 2022; 358:127416. [PMID: 35660656 DOI: 10.1016/j.biortech.2022.127416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
The formation of bulking and foaming in biological wastewater treatment could cause a series of operational issues with biomass and effluent quality, ultimately affect the treatment performance of the system. The essential parameters influencing the growth of bulking and foaming bacteria are comprehensively summarised in this paper. Existing bulking and foaming control approached are critically reviewed and addressed, as well as their drawbacks and limitations. Despite the abundance of information and implementation, a complete control technique for limiting filamentous sludge bulking and foaming remains insufficient. Magnetic field application is emphasised as a viable control strategy in this regard. The present review study provides new insight of this application by comparing the use of magnetic fields to conventional treatments. Future outlooks on the use of magnetic fields to prevent BFB proliferation were also highlighted.
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Affiliation(s)
- Nur Syamimi Zaidi
- School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia (UTM), 81310 Johor Bahru, Johor, Malaysia; Centre for Environmental Sustainability and Water Security (IPASA), Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia
| | - Achmad Syafiuddin
- Environmental Health Division, Department of Public Health, Universitas Nahdlatul Ulama Surabaya, 60237 Surabaya, East Java, Indonesia
| | - Mika Sillanpää
- Department of Civil and Environmental Engineering, Florida International University, Miami, USA
| | - Muhammad Burhanuddin Bahrodin
- School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia (UTM), 81310 Johor Bahru, Johor, Malaysia
| | - Loh Zhang Zhan
- School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia (UTM), 81310 Johor Bahru, Johor, Malaysia
| | - Anisa Ratnasari
- School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia (UTM), 81310 Johor Bahru, Johor, Malaysia
| | - Abudukeremu Kadier
- Laboratory of Environmental Science and Technology, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, China
| | - Muhammad Aamer Mehmood
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad 38000, Pakistan
| | - Raj Boopathy
- Department of Biological Sciences, Nicholls State University, Thibodaux, LA 70310, USA.
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Maal-Bared R. Operational impacts of heavy metals on activated sludge systems: the need for improved monitoring. ENVIRONMENTAL MONITORING AND ASSESSMENT 2020; 192:560. [PMID: 32748335 DOI: 10.1007/s10661-020-08529-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
Biological nutrient removal is highly reliant on maintaining a heterogeneous, balanced, and metabolically active microbial community that can adapt to the fluctuating composition of influent wastewater and encompassing environmental conditions. Maintaining this balance can be challenging in municipal wastewater systems that sporadically receive wastewater from industrial facilities due to the impact of heavy metals and other contaminants on the microbial ecology of the activated sludge. A thorough understanding of the impacts of heavy metals on activated sludge and of practical monitoring options is needed to support decision-making at the wastewater utility level. This paper is divided into two parts. In the first part, the review explains what happens when heavy metals interact with activated sludge systems by highlighting biosorption and bioaccumulation processes, and when an activated sludge system switches from bioaccumulation to toxic shock. Here, it also summarizes the impacts of heavy metal exposure on plant performance. In the second part, the review summarizes practical approaches that can be used at the plant outside the realm of traditional toxicological bioassays testing to determine the possible impacts of influent heavy metal concentrations on the BNR process. These approaches include the following: monitoring operational parameters for major shifts; respirometry; microscopy; ATP; chemical analyses of heavy metals with a focus on synergistic impacts and inhibitory limits; and other novel approaches, such as EPS chemical analyses, molecular techniques, and quorum sensing.
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Affiliation(s)
- Rasha Maal-Bared
- Scientific Services, Quality Assurance and Environment, EPCOR Water Canada, EPCOR Tower, 2000 10423 101 Street, Edmonton, AB, T5H 0E8, Canada.
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Ma B, Li Z, Wang S, Liu Z, Li S, She Z, Yu N, Zhao C, Jin C, Zhao Y, Guo L, Gao M. Insights into the effect of nickel (Ni(II)) on the performance, microbial enzymatic activity and extracellular polymeric substances of activated sludge. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 251:81-89. [PMID: 31071636 DOI: 10.1016/j.envpol.2019.04.094] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/15/2019] [Accepted: 04/18/2019] [Indexed: 05/27/2023]
Abstract
The performance, nitrogen removal rate, microbial enzymatic activity and extracellular polymeric substances (EPS) of activated sludge were assessed under nickel (Ni(II)) stress. The organic matter and NH4+-N removal efficiencies were stable at less than 10 mg/L Ni(II) and subsequently decreased with the increment of Ni(II) concentration from 10 to 30 mg/L. The specific oxygen uptake rate and dehydrogenase activity kept stable at less than 5 mg/L Ni(II) and then declined at 5-30 mg/L Ni(II). Both specific ammonia-oxidizing rate (SAOR) and specific nitrite-oxidizing rate (SNOR) decreased with the increment of Ni(II) concentration. The changing trends of ammonia monooxygenase and nitrite oxidoreductase activities were matched those of SAOR and SNOR, respectively. The nitrite-reducing rate and nitrate-reducing rate illustrated a similar variation tendency to the nitrite reductase activity and nitrate reductase activity, respectively. Ni(II) impacted on the production, chemical composition and functional group of EPS. The relation between the sludge volume index and the EPS production exhibited a better linear function with a negative slope, demonstrating that Ni(II) improved the sludge settleability despite of the increase of EPS production.
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Affiliation(s)
- Bingrui Ma
- Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Zhiwei Li
- Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Sen Wang
- School of Environmental Science and Engineering, Qingdao University, Qingdao, 266071, China
| | - Zhaozhe Liu
- Qingjian International Group Co., Ltd, Qingdao, 266000, China
| | - Shanshan Li
- Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Zonglian She
- Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Naling Yu
- Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Changkun Zhao
- Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Chunji Jin
- Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Yangguo Zhao
- 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
| | - Liang Guo
- Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Mengchun Gao
- Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.
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Wu D, Zhang Q, Xia WJ, Shi ZJ, Huang BC, Fan NS, Jin RC. Effect of divalent nickel on the anammox process in a UASB reactor. CHEMOSPHERE 2019; 226:934-944. [PMID: 31509923 DOI: 10.1016/j.chemosphere.2019.03.121] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 03/05/2019] [Accepted: 03/17/2019] [Indexed: 06/10/2023]
Abstract
The anaerobic ammonium oxidation (anammox) process has the advantages of a high nitrogen removal rate, low operational cost, and small footprint and has been successfully implemented to treat high-content ammonium wastewater. However, very little is known about the toxicity of the heavy metal element Ni(II) to the anammox process. In this study, the short- and long-term effects of Ni(II) on the anammox process in an upflow anaerobic sludge blanket (UASB) reactor were revealed. The results of the short-term batch test showed that the half maximal inhibitory concentration (IC50) of Ni(II) on anammox biomass was 14.6 mg L-1. A continuous-flow experiment was performed for 150 days of operation, and the results illustrated that after domestication, the achieved nitrogen removal efficiency was up to 93±0.03% at 10 mg L-1 Ni(II). The settling velocity, specific anammox activity and EPS content decreased as the Ni(II) concentration increased. Nevertheless, the content of heme c increased as the Ni(II) increased. These results indicate that short-term exposure to Ni(II) has an adverse impact on anammox process, but the anammox system could tolerate 10 mg L-1 Ni(II) stress after acclimation during continuous-flow operation for 150 days. High-throughput sequencing results indicated that the presence of Ni(II) had an impact on the microbial community composition in the anammox reactor, especially Candidatus Kuenenia. At Ni(II) concentrations of 0-10 mg L-1, the relative abundance of Candidatus Kuenenia decreased from 36.23% to 28.46%.
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Affiliation(s)
- Dan Wu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China; Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, Hangzhou Normal University, Hangzhou, 310036, China
| | - Quan Zhang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China; Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, Hangzhou Normal University, Hangzhou, 310036, China
| | - Wen-Jing Xia
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China; Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, Hangzhou Normal University, Hangzhou, 310036, China
| | - Zhi-Jian Shi
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China; Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, Hangzhou Normal University, Hangzhou, 310036, China
| | - Bao-Cheng Huang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China; Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, Hangzhou Normal University, Hangzhou, 310036, China
| | - Nian-Si Fan
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China; Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, Hangzhou Normal University, Hangzhou, 310036, China
| | - Ren-Cun Jin
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China; Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, Hangzhou Normal University, Hangzhou, 310036, China.
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Zou G, Papirio S, van Hullebusch ED, Puhakka JA. Fluidized-bed denitrification of mining water tolerates high nickel concentrations. BIORESOURCE TECHNOLOGY 2015; 179:284-290. [PMID: 25549902 DOI: 10.1016/j.biortech.2014.12.044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 12/11/2014] [Accepted: 12/12/2014] [Indexed: 05/14/2023]
Abstract
This study revealed that fluidized-bed denitrifying cultures tolerated soluble Ni concentrations up to 500 mg/L at 7-8 and 22°C. From 10 to 40 mg/L of feed Ni, denitrification resulted in complete nitrate and nitrite removal. The concomitant reduction of 30 mg/L of sulfate produced 10 mg/L of sulfide that precipitated nickel, resulting in soluble effluent Ni below 22 mg/L. At this stage, Dechloromonas species were the dominant denitrifying bacteria. From 60 to 500 mg/L of feed Ni, nickel remained in solution due to the inhibition of sulfate reduction. At soluble 60 mg/L of Ni, denitrification was partially inhibited prior to recover after 34 days of enrichment by other Ni-tolerant species (including Delftia, Zoogloea and Azospira) that supported Dechloromonas. Subsequently, the FBR cultures completely removed nitrate even at 500 mg/L of Ni. Visual Minteq speciation model predicted the formation of NiS, NiCO3 and Ni3(PO4)2, whilst only Ni3(PO4)2 was detected by XRD.
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Affiliation(s)
- G Zou
- Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland.
| | - S Papirio
- Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland
| | - E D van Hullebusch
- Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 77454 Marne-la-Vallée, France
| | - J A Puhakka
- Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland
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Yan Y, Wang Y, Liu Y, Liu X, Yao C, Ma L. Effect of continuously dosing Cu(II) on pollutant removal and soluble microbial products in a sequencing batch reactor. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2015; 72:1653-1661. [PMID: 26524458 DOI: 10.2166/wst.2015.385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The effects of synthetic wastewater that contained 20 mg/L Cu(II) on the removal of organic pollutants in a sequencing batch reactor were investigated. Results of continuous 20 mg/L Cu(II) exposure for 120 days demonstrated that the chemical oxygen demand (COD) removal efficiency decreased to 42% initially, followed by a subsequent gradual recovery, which peaked at 78% by day 97. Effluent volatile fatty acid (VFA) concentration contributed 67 to 89% of the influent COD in the experimental reactor, which indicated that the degradation of the organic substances ceased at the VFA production step. Meanwhile, the varieties of soluble microbial products (SMP) content and main components (protein, polysaccharide, and DNA) were discussed to reveal the response of activated sludge to the toxicity of 20 mg/L Cu(II). The determination of Cu(II) concentrations in extracellular polymeric substances (EPS) and SMP throughout the experiment indicated an inverse relationship between extracellular Cu(II) concentration and COD removal efficiency.
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Affiliation(s)
- YangWei Yan
- Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433, China E-mail:
| | - YuWen Wang
- Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433, China E-mail:
| | - Yan Liu
- Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433, China E-mail:
| | - Xiang Liu
- Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433, China E-mail:
| | - ChenChao Yao
- Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433, China E-mail:
| | - LuMing Ma
- College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
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Li J, Liu X, Liu Y, Ramsay J, Yao C, Dai R. The effect of continuous exposure of copper on the properties and extracellular polymeric substances (EPS) of bulking activated sludge. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2011; 18:1567-1573. [PMID: 21584640 DOI: 10.1007/s11356-011-0492-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2010] [Accepted: 03/11/2011] [Indexed: 05/30/2023]
Abstract
INTRODUCTION This study investigated the effect of copper on chemical oxygen demand (COD) removal efficiency and on the properties (mainly settling and dewatering) and the composition of extracellular polymeric substances (EPS) when 20 mg/L Cu(II) was continuously dosed to a sequencing batch reactor (SBR) inoculated with activated sludge. MATERIALS AND METHODS The results showed that the continuous addition of 20 mg/L Cu(II) seriously inhibited the removal of sodium benzoate (provided as a model organic pollutant) by activated sludge in a SBR. RESULTS AND DISCUSSION After 40 days of acclimation, the removal efficiency presented a slight but unsteady recovery and the settling and dewatering properties improved, indicating that sludge bulking had been inhibited. Additionally, the proportion of loosely bound EPS in the total EPS increased with time and the relative composition of the total organics was polysaccharide > humic substances > protein > DNA. CONCLUSION The effects of copper on the composition of EPS and the settling and dewatering properties of bulking activated sludge were also discussed for the first time in this paper.
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Affiliation(s)
- Jia Li
- Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433, China
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