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Sato Y, Xiang Y, Cooper P, Cassol GS, Luo Y, Zeng Q, Shang C, Ren ZJ, Chen G. Evaluating UV 254 absorbance reductions in landfill leachate for municipal sewage co-treatment through timed UV/electrooxidation. J Hazard Mater 2023; 445:130624. [PMID: 37056023 DOI: 10.1016/j.jhazmat.2022.130624] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/25/2022] [Accepted: 12/16/2022] [Indexed: 06/19/2023]
Abstract
Landfill leachate contains dissolved organic matter (DOM) exhibiting high ultraviolet absorbance at 254 nm (UVA254). The UVA254 limits leachate co-treatment with municipal sewage by hindering the downstream UV disinfection efficiency at wastewater treatment plants. Here, we alleviated the UVA254 by timing the radiation in a UV/electrooxidation (UV/EO) process to accelerate reactive species formation. At 200 A·m-2, the UV radiation was delayed by 10 min to accumulate 21 mg·L-1 as Cl2, which enhanced the initial radical formation rate by 5.25 times compared with a simultaneous UV/EO. The timed operation increased the steady-state concentrations of ClO• by 700 times to 4.11 × 10-14 M and reduced the leachate UVA254 by 78.2% after 60 min. We identified that aromatic formulas with low oxygen content were susceptible to UV/EO from Fourier-transform ion cyclotron resonance mass spectrometry analysis. The toxicity of the treated leachate and generated byproducts was assessed through specific oxygen uptake rates (SOUR) and developmental assays with Platynereis dumerilii. After quenching the residual chlorine, leachate co-treatment at 3.5% v/v presented minimal toxicological risk. Our findings provide operational insights for applying UV/EO in high UVA254 matrices such as landfill leachate.
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Affiliation(s)
- Yugo Sato
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Yingying Xiang
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Patrick Cooper
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Gabriela Scheibel Cassol
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Yu Luo
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Qian Zeng
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Chii Shang
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China; Fok Ying Tung Research Institute, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Zhiyong Jason Ren
- Department of Civil and Environmental Engineering and the Andlinger Center for Energy and the Environment, Princeton University, Princeton, NJ 08544, USA
| | - Guanghao Chen
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China; Fok Ying Tung Research Institute, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
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Meng HQ, Li HX, Zhao AP, Yuan JG, Zhang D. [Systematic Evaluation of Low-carbon Operation of Typical A 2O Processes in Municipal Sewage Plant]. Huan Jing Ke Xue 2023; 44:1174-1180. [PMID: 36775639 DOI: 10.13227/j.hjkx.202204042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Under the "Carbon Peak, Carbon Neutral" goal, the systematic evaluation of the carbon emission equivalent (CO2eq) and its compositions of the typical A2O process has important guiding significance for the low-carbon operation of most municipal sewage plants in China. Based on the operational data on the first municipal sewage plant of Jiaozuo in 2020 and the methods presented in "2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, " a systematic evaluation of the CO2eq of the typical A2O process was established, including direct emissions that were built on the Arrhenius model introducing the water temperature factor and indirect emissions from the three aspects of electricity consumption, agent addition, and sludge transportation. The results showed that the daily emission intensities of CH4 and N2O were (115±56) kg·d-1 and (30±18) kg·d-1, respectively. Additionally, indirect carbon emissions from electricity consumption and agent addition accounted for 48.4% and 51.3% in the biochemical treatment section, respectively. In 2020, CO2eq amounts of total research plant and per unit sewage were 2.17×104 t and (0.63±0.07) kg·m-3, respectively. The magnitude of the proportion of different carbon emission compositions was as follows:sewage electricity (36.5%)>sewage agent (26.6%)>N2O direct (15.4%)>sludge agent (9.6%)>sludge electricity (6.7%)>CH4 direct (4.9%)>sludge transportation (0.3%). System import/export fluxes of carbon and nitrogen elements were calculated, followed by the carbon to nitrogen mass ratio in the sewage plant. Direct carbon emission characteristics of CH4 and N2O and their influencing factors were discussed, respectively. Based on the balance theory of carbon and nitrogen elements in the system, it is proposed that the selective introduction of industrial wastewater may become an important reference measure for the low-carbon operation of municipal sewage plants in the future.
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Affiliation(s)
- Hong-Qi Meng
- Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo 454000, China
| | - Hong-Xia Li
- Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo 454000, China
| | - Ai-Ping Zhao
- Kangda Environmental Protection Water Co., Ltd., Jiaozuo 454000, China
| | - Jian-Guang Yuan
- Kangda Environmental Protection Water Co., Ltd., Jiaozuo 454000, China
| | - Dong Zhang
- Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo 454000, China
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Yu LF, Wang Y, Hua SS, Li R, Zhang XX, Hui XF. [Seasonal Effects of Influent Ammonia Oxidizing Bacteria of Municipal Wastewater Treatment Plants on Activated Sludge System]. Huan Jing Ke Xue 2021; 42:1923-1929. [PMID: 33742827 DOI: 10.13227/j.hjkx.202008075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The specific ammonia uptake rates (SAUR) and ammonia oxidizing bacteria (AOB) community of influent sewage and activated sludge in the 2nd wastewater treatment plant (WWTP) of Xi'an without the primary settling tank were analyzed over multiple years to explore the seasonal effects of the influent AOB on the activated sludge systems. During the experiment, the SAUR of the raw sewage and activated sludge were 0.48-3.02 mg·(g·h)-1 and 0.68-2.25 mg·(g·h)-1, respectively. Meanwhile, the correlation analysis indicated that the monthly SAUR of the raw sewage was highly correlated with that of the activated sludge of the following month (r=0.862,P<0.05), which indicated that influent nitrifiers had a significant effect on the nitrification performance of activated sludge. Considering that the estimated AOB seeding intensities based on the ammonia oxidizing activity were 0.21-0.92 g·(g·d)-1, the nitrifier immigration from the raw sewage should added to the design of WWTP and the activated sludge modeling. Moreover, the qPCR results revealed that the AOB abundance of activated sludge in winter decreased but remained at 1010 cells·g-1, indicating that the immigration of influent nitrifiers could partially compensate for the reduction of the AOB abundance in the activated sludge caused by decreasing temperatures. Finally, the Illumina MiSeq sequencing demonstrated that the shared dominant AOB between the raw sewage and activated sludge were Nitrosomonas sp. Nm58, Nitrosomonas sp. JL21, and bacterium CYCU-0253. These findings can provide theoretical support for the design and operation of a WWTP.
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Affiliation(s)
- Li-Fang Yu
- School of Municipal and Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.,Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Yu Wang
- School of Municipal and Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Si-Si Hua
- School of Municipal and Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Ren Li
- School of Municipal and Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Xing-Xiu Zhang
- School of Municipal and Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Xiao-Fei Hui
- School of Municipal and Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
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Ali Z, Mohammad A, Riaz Y, Shakeel A, Khan KY, Quraishi UM, Malik RN. Heavy metal phyto-accretion, biochemical responses and non-carcinogenic human health risks of genetically diverse wheat genotypes cultivated with sewage of municipal origin. Int J Phytoremediation 2020; 23:619-631. [PMID: 33232176 DOI: 10.1080/15226514.2020.1847033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Current study explored the effects of municipal sewage (MS) irrigation on heavy metal phyto-accretion, biochemical responses and human health risks of diverse wheat genotypes along with recycled municipal sewage (RMS). Mean concentrations of PO43-, NO3--N, chemical oxygen demand, biological oxygen demand, K, Co, Cu, Cd, Cr and Ni were found higher in MS than irrigation criteria. This led to significant increase in heavy metal contents in roots, stem and grains of MS irrigated wheat genotypes compared to RMS and control treatments. No adverse health risk effects for individual or multiple metals were recorded in RMS irrigated wheat genotypes on grounds of lowest heavy metal accumulation. Multivariate techniques i.e. principal component analyses (PCA) and hierarchical agglomerative cluster analyses (HACA) identified tolerant (inefficient metal accumulators) and sensitive (efficient metal accumulators) wheat genotypes in MS and RMS. Tolerant wheat genotypes showed lowest accumulation of heavy metals, efficient biochemical mechanisms to combat oxidative stress and lower health risks to adults/children. Cultivation of identified tolerant wheat genotypes is recommended in areas receiving municipal wastes to reduce human and environmental health risks. Moreover, genetic potential of identified tolerant wheat genotypes from MS and RMS can be utilized in breeding heavy metal tolerant wheat germplasm worldwide.
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Affiliation(s)
- Zeshan Ali
- Department of Plant Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
- National Institute of Bioremediation, Department of Plant and Environmental Protection, National Agricultural Research Center, Islamabad, Pakistan
- Plant Physiology Program, Crop Sciences Institute, National Agricultural Research Centre, Islamabad, Pakistan
| | - Ashiq Mohammad
- National Institute of Bioremediation, Department of Plant and Environmental Protection, National Agricultural Research Center, Islamabad, Pakistan
| | - Yousaf Riaz
- National Institute of Bioremediation, Department of Plant and Environmental Protection, National Agricultural Research Center, Islamabad, Pakistan
| | - Adnan Shakeel
- Climate, Energy and Water Research Institute, National Agricultural Research Centre, Islamabad, Pakistan
| | - Kiran Yasmin Khan
- Key Laboratory of Advanced Process Control for Light Industry, Ministry of Education, Jiangnan University, Wuxi, China
| | - Umar Masood Quraishi
- Department of Plant Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Riffat Naseem Malik
- Environmental Biology and Ecotoxicology Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
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Wu CL, Rong Y, Liu XP, Shi HX, Zhang WS, Jin PK, Ma WW. [Partial Nitrification and Denitrification of Low C/N Ratio Sewage Based on Zoning Oxygen and Dissolved Oxygen Control]. Huan Jing Ke Xue 2019; 40:2310-2316. [PMID: 31087871 DOI: 10.13227/j.hjkx.201809038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Poor nitrogen removal from municipal sewage is mainly due to insufficient carbon source and low C/N ratio. The A2/O pilot plant was established to investigate the accumulation rate of nitrous nitrogen and the removal of nitrogen pollutants by adjusting the ratio of anoxic/aerobic zoning and dissolved oxygen levels in the aerobic zone. The results showed that when DO is 2.0-2.5 mg·L-1, changing the ratio of anoxic to aerobic zoning had little effect on the reaction system, and it was difficult to realize partial nitrification. When DO is 0.5-0.8 mg·L-1, VAnoxic:VAerobic=1:1, this is the best working condition of the system. The accumulation rate of nitrous nitrogen at the end of aerobic zone is stable at more than 62%, and the total nitrogen of effluent is reduced to 9.0 mg·L-1, which can achieve the goal of deep denitrification. Analyzing the apparent activity of nitrifying bacteria, it was found that the SAOR and SNOR (according to N/VSS calculation) were 0.14 g·(g·d)-1 and 0.04 g·(g·d)-1, respectively, under the optimum conditions. The difference between them was more obvious than that in other stages of the experiment, that is, the higher inhibition of NOB activity was the direct reason for the increase of nitrite accumulation rate. Illumina MiSeq sequencing showed that the number of NOB in this stage was significantly lower than that in other stages. Intermittent OUR method was used to analyze the composition of carbon sources at the inlet and outlet of the anoxic zone. The results showed that short-cut nitrification and denitrification could save 27.3% of the carbon sources under the optimal operating conditions. The biodegradable COD consumption in the anoxic zone was 63.6%, which was much higher than that in other stages.
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Affiliation(s)
- Chun-Lei Wu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Yi Rong
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Xiao-Peng Liu
- Xi'an Fifth Sewage Treatment Plant, Xi'an 710016, China
| | - Hui-Xin Shi
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Wu-Shou Zhang
- Shaanxi Langzheng Environmental Protection Technology Co., Ltd., Xi'an 710065, China
| | - Peng-Kang Jin
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Wen-Wei Ma
- Shaanxi Environmental Protection Group Water Environment Co., Ltd., Xi'an 710003, China
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Das S, Chaudhari S. Effect of reactor configuration on performance during anaerobic treatment of low strength wastewater. Environ Technol 2015; 36:2312-2318. [PMID: 25751650 DOI: 10.1080/09593330.2015.1026845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The efficiency of the up-flow anaerobic sludge blanket (UASB) reactor is quite low for the treatment of low strength wastewaters (LSWs) due to less biogas production leading to poor mixing. LSW may be treated efficiently by providing adequate mixing in the UASB reactor when gas production is low, and sufficient mixing can be achieved by modifying reactor geometry. Hence, modifying UASB reactor geometry for enhanced mixing and evaluating its performance for the treatment of LSWs would be a worthwhile effort. In the present study, UASB reactor configuration was modified by providing a vertical baffle along the height to promote mixing of reactor contents, and is termed as modified UASB (MUASB). The performance of an on-site pilot-scale MUASB reactor was evaluated for 375 days under ambient condition for the treatment of municipal sewage as LSW and compared with that of the conventional UASB and hybrid UASB (HUASB) reactors. The MUASB reactor showed better performance in terms of chemical oxygen demand (COD) removal efficiency as compared with UASB and HUASB reactors during this study. At 4 h hydraulic retention time, the total COD removal efficiency of UASB and HUASB reactors was 53.7% and 61%, respectively, which were much lower than the total COD removal efficiency of the MUASB reactor (72.7%). The better performance observed in the MUASB reactor is possibly due to improved mixing. Depth-wise analysis of reactor liquid showed that better mixing in the MUASB reactor enhances the contact of wastewater with biomass, which contributes to the improved treatment efficiency. It seems that MUASB holds promise for LSW treatment.
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Affiliation(s)
- Suprotim Das
- a Research & Development , Tata Steel Limited , Jamshedpur 831001 , India
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