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Wang Q, Ko JH, Liu F, Xu Q. Leaching characteristics of heavy metals in MSW and bottom ash co-disposal landfills. JOURNAL OF HAZARDOUS MATERIALS 2021; 416:126042. [PMID: 34492889 DOI: 10.1016/j.jhazmat.2021.126042] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 04/06/2021] [Accepted: 05/02/2021] [Indexed: 06/13/2023]
Abstract
Bottom ash (BA) management is often implemented through its co-disposal with municipal solid waste (MSW) in landfills. However, BA co-disposal may lead to heavy metal leaching in landfills. In this study, the effect of BA co-disposal on heavy metal leaching behavior under different scenarios, specifically, MSW, low BA co-disposal (BA_L), high BA co-disposal (BA_H), and BA monofill were investigated. The heavy metal concentrations in the leachate decreased in landfills over time. The leached metals primarily included Zn, Cu, Mn, Pb, Cr, and Cd. The discharge concentration ratio of heavy metals in the leachates exhibited the following decreasing order: MSW, BA_L, BA_H, and BA. In particular, the discharge concentration ratio of Cu in the MSW, BA_L, BA_H, and BA cases ranged from 7.1 × 10-3 to 8.8 × 10-1 (mean = 3.0 ×10-1), 2.8 × 10-4 to 2.0 × 10-1 (mean = 5.4 ×10-2), 9.1 × 10-5 to 3.0 × 10-2 (mean = 5.9 ×10-3), and 4.4 × 10-4 to 7.9 × 10-3 (mean = 1.8 ×10-3), respectively. Moreover, the leaching of the heavy metals could be attributed to waste contents, properties of the heavy metals, and leachate characteristics, such as the pH, chemical oxygen demand (COD), alkalinity, and Cl- content. The presented findings can help clarify the leaching characteristics of heavy metals in BA co-disposal landfills, thereby facilitating the optimization of practical landfills.
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Affiliation(s)
- Qian Wang
- School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Xili, Nanshan District, Shenzhen 518055, PR China
| | - Jae Hac Ko
- Department of Environmental Engineering, College of Ocean Sciences, Jeju National University, Jeju Special Self-Governing Province 63243, Republic of Korea
| | - Feng Liu
- School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Xili, Nanshan District, Shenzhen 518055, PR China
| | - Qiyong Xu
- School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Xili, Nanshan District, Shenzhen 518055, PR China.
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2
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Hettiaratchi JPA, Jayasinghe PA, Yarandy TA, Attalage D, Jalilzadeh H, Pokhrel D, Bartholameuz E, Hunte C. Innovative Practices to Maximize Resource Recovery and Minimize Greenhouse Gas Emissions from Landfill Waste Cells: Historical and Recent Developments. J Indian Inst Sci 2021. [DOI: 10.1007/s41745-021-00230-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Jiang G, Liu D, Chen W, Han Z, Li Q. Greenhouse gas emissions from semi-aerobic bioreactor landfills with different vent-pipe diameters. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:17563-17572. [PMID: 33400112 DOI: 10.1007/s11356-020-12047-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
The emission patterns of three greenhouse gasses (GHGs), viz. CH4, CO2, and N2O from landfills, were examined on a lab scale. Three simulated semi-aerobic bioreactor landfills (SABL1, SABL2, SABL3), with respective vent-pipe inner diameters (φ) of 25, 50, and 75 mm, were used to investigate their effect on the greenhouse effect (GHE) during the municipal solid waste (MSW) stabilization process. We found that the vent-pipe φ influenced both MSW degradation and GHG emissions, increasing the vent-pipe φ which improved the removal of carbon and nitrogen-based pollutants. The GHG emissions were 364, 356, and 309 kg CO2 equivalents per ton of MSW from the SABL2, SABL1, and SABL3, respectively, during the operation of 465 days. Of the three GHGs, CH4 influenced the GHE the most, contributing 72.53%, 79.17%, and 71.42% in SABL1, SABL2, and SABL3, respectively. In the same sequence, CO2 (14.87%, 14.06%, and 21.9%) and N2O (12.6%, 6.77%, and 6.69%) were the second and third contributors to the GHE, respectively. Considering the rapidly MSW stabilization and the mitigation of GHG emissions, a vent pipe with φ of 75 mm in the SABL column (φ of 800 mm) was suggested. Moreover, the GHG mitigation in the SABL should be implemented by prioritizing CH4 collection and oxidation. The results provided a technical guidance for GHG mitigation in MSW management.
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Affiliation(s)
- Guobin Jiang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, People's Republic of China
| | - Dan Liu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, People's Republic of China
| | - Weiming Chen
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, People's Republic of China
| | - Zhiyong Han
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu, 610059, China
| | - Qibin Li
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, People's Republic of China.
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Ma J, Liu L, Xue Q, Yang Y, Zhang Y, Fei X. A systematic assessment of aeration rate effect on aerobic degradation of municipal solid waste based on leachate chemical oxygen demand removal. CHEMOSPHERE 2021; 263:128218. [PMID: 33297175 DOI: 10.1016/j.chemosphere.2020.128218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/09/2020] [Accepted: 08/29/2020] [Indexed: 06/12/2023]
Abstract
Aeration is one mainstream technique to accelerate municipal solid waste (MSW) degradation in landfills. The determination of an appropriate aeration rate is critical to the design and operation of a landfill aeration system. In this study, we analyze 132 waste degradation tests reported in forty one studies in the literature. We use L min-1 kg-1 dry organic matter (L min-1 kg-1 DOM) as the uniform unit to quantify the aeration rates in all tests. The first order rate coefficient for chemical oxygen demand (COD) removal in leachate (kCOD) is selected as the parameter to characterize MSW degradation process. We further divide aerobic tests into five aerobic groups base on the respective aeration rates, i.e., <0.02, 0.02-0.1, 0.1-0.3, 0.3-1, and >1 L min-1 kg-1 DOM. With an increase in the aeration rate, the kCOD increases first and then decreases. The aeration rate between 0.1 and 0.3 L min-1 kg-1 DOM has the best enhancement on the kCOD. The kCOD values are not much higher than the anaerobic and semi-aerobic tests when the aeration rates are <0.1 L min-1 kg-1 DOM, because such aeration rates may be lower than the actual oxygen consumption rates. An aeration rate >0.3 L min-1 kg-1 DOM reduces the kCOD likely due to excess water evaporation and ventilation cooling. Among the analyzed results, the aeration rate is the most related to the kCOD in principal component analysis than the other factors, including liquid recirculation and addition, waste total density, waste degradation level, and waste initial temperature.
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Affiliation(s)
- Jun Ma
- State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, 430071, China; University of Chinese Academy of Sciences, Beijing, 100049, China; IRSM-CAS/HK PolyU Joint Laboratory on Solid Waste Science, Wuhan, 430071, China; Hubei Province Key Laboratory of Contaminated Sludge and Soil Science and Engineering, Wuhan, 430071, China
| | - Lei Liu
- State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, 430071, China; IRSM-CAS/HK PolyU Joint Laboratory on Solid Waste Science, Wuhan, 430071, China; Hubei Province Key Laboratory of Contaminated Sludge and Soil Science and Engineering, Wuhan, 430071, China.
| | - Qiang Xue
- State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, 430071, China; IRSM-CAS/HK PolyU Joint Laboratory on Solid Waste Science, Wuhan, 430071, China; Hubei Province Key Laboratory of Contaminated Sludge and Soil Science and Engineering, Wuhan, 430071, China
| | - Yong Yang
- Beijing Water Science and Technology Institute, Beijing Engineering Technique Research Center for Exploration and Utilization of Non-Conventional Water Resources and Water Use Efficiency, Beijing, 100048, China
| | - Yi Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Xunchang Fei
- School of Civil and Environmental Engineering, Nanyang Technological University, Nanyang Avenue, 639798, Singapore; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, 1 Cleantech Loop, 637141, Singapore.
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Zhang S, Wang Y, Liu S. Process optimization for the anaerobic digestion of poplar ( Populus L.) leaves. Bioengineered 2020; 11:439-448. [PMID: 32189559 PMCID: PMC7161560 DOI: 10.1080/21655979.2020.1739823] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/29/2022] Open
Abstract
This study investigates the optimized condition for enhancing biogas production in the anaerobic digestion of fallen poplar leaves. Two experiments were conducted: (1) The calcium hydroxide concentration, bacteria concentration, and composting time were used as three parameters to optimize the fermentation pretreatment condition and contrasting tests were performed; and (2) a series of fermentation tests were conducted to explore the best process parameters and biogas production characteristics. The results showed that a biological and chemical combined pretreatment effectively improved the biogas productivity of poplar leaves as fermentation substrates, and the parameter that had the greatest effect during anaerobic digestion was temperature followed by the solid concentration and pH value. The optimal pretreatment condition was: alkali concentration 4.61%, bacterial concentration 0.20‰, and a composting time of 6.6 days. By considering the factors that affect the fermentation of poplar leaves and the cumulative gas production, the optimum condition for poplar leave digestion was found to be a temperature of 30°C, a pH of 7, and a 10% solid concentration. In addition, the methane yield of the optimized trial was well fitted using the modified Gompertz model.
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Affiliation(s)
- Shuqing Zhang
- Key Laboratory of Renewable Energy of Ministry of Agriculture, Henan Agricultural University/Collaborative Innovation Center of Biomass Energy, Zhengzhou, China
| | - Yanling Wang
- Key Laboratory of Renewable Energy of Ministry of Agriculture, Henan Agricultural University/Collaborative Innovation Center of Biomass Energy, Zhengzhou, China
| | - Shengyong Liu
- Key Laboratory of Renewable Energy of Ministry of Agriculture, Henan Agricultural University/Collaborative Innovation Center of Biomass Energy, Zhengzhou, China
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Campanaro S, Raga R, Squartini A. Intermittent aeration of landfill simulation bioreactors: Effects on emissions and microbial community. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 117:146-156. [PMID: 32828012 DOI: 10.1016/j.wasman.2020.08.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 06/11/2023]
Abstract
Landfill simulation experiments were run at lab-scale to compare the effects of intermittent and continuous aeration on the evolution of leachate composition and biogas production. The experiments were carried out using six reactors; two of them under continuous aeration, two under intermitted aeration and two anaerobic as a control. Different aeration regimes produced different effects on reactors. As expected, carbon discharge via biogas was higher in reactors under continuous aeration than under intermittent aeration. The evolution of leachate quality was affected by the aeration regimes; however, at test end very similar concentration were ascertained for relevant leachate parameters in all aerated reactors. A comprehensive description of the aerobic and anaerobic landfill microbiome is provided, using a metagenomic approach focused on the microbial genome reconstruction. A time course investigation evidenced the modification of the microbiome and revealed taxa and specific microbes more strictly connected to the environmental parameters of the reactors. Methanoculleus, Syntrophomonas and Parabacteroides were identified as the genera more strictly connected to biogas production, while numerous species belonging to Thiomonas, Nitrosomonas, Xanthomonadaceae, Myxococcales and Alcaligenaceae were found to be connected with NH4+ oxidation.
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Affiliation(s)
- Stefano Campanaro
- Department of Biology, University of Padua, via U. Bassi 58/b, 35131 Padova, Italy
| | - Roberto Raga
- ICEA, Department of Civil, Environmental and Architectural Engineering, University of Padua, via Marzolo 9, 35131 Padova, Italy.
| | - Andrea Squartini
- Department of Agronomy, Food, Natural Resources, Animals and Environment, DAFNAE, University of Padua, viale dell'Università 16, 35020 Legnaro (PD), Italy
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Barati rashvanlou R, Rezaee A, Farzadkia M, Gholami M, Kermani M. Effect of micro-aerobic process on improvement of anaerobic digestion sewage sludge treatment: flow cytometry and ATP assessment. RSC Adv 2020; 10:35718-35728. [PMID: 35517111 PMCID: PMC9056904 DOI: 10.1039/d0ra05540a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 08/07/2020] [Indexed: 11/21/2022] Open
Abstract
Micro-aeration as a pretreatment method improves the efficiency of anaerobic digestion of municipal sewage sludge and consequently promotes the methane production. In this study, adenosine triphosphate (ATP) and flow cytometry (FCM) were employed to monitor the performance of the micro-aerobic process and investigate the survival of bacterial cells within the process. At first, the effect of air flow rate (AFR) (0.1, 0.2, 0.3 and 0.5 vvm) on hydrolysis of mixed sludge in 5 aeration cycles (20, 30, 40, 48 and 60 hours) was examined. Then, the effects of the micro aerobic process on methane (CH4) production in anaerobic digestion were surveyed. The highest VSS reduction was 30.6% and 10.4% for 40 hours in the reactor and control, respectively. Soluble COD also fluctuated between 40.87 and 65.14% in micro-aerobic conditions; the highest SCOD was achieved at the time of 40 h. Microbial activities were increased by 597%, 170% and 79.4% for 20, 30 and 40 h pretreatment with the micro-aerobic process, respectively. Apoptosis assay showed that micro-aerobic pre-treatment at 20, 30 and 40 h increased the percentage of living cells by 57.4, 62.8 and 67.9%, respectively. On the other hand, FCM results showed that the highest percentage of viable bacteria (i.e., 67.9%) was observed at 40 h pretreating which was approximately 40% higher the ones for the control. Variation in cumulative methane production shows that methane production was increased by 221% compared to anaerobic digestion (control group). Therefore, ATP and FCM can be employed as two appropriate, accurate, relatively specific indicators for monitoring the process and bacteria viability. Micro-aeration as a pretreatment method improves the efficiency of anaerobic digestion of municipal sewage sludge and consequently promotes the methane production.![]()
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Affiliation(s)
- Reza Barati rashvanlou
- Research Center for Environmental Health Technology
- Iran University of Medical Sciences
- Tehran
- Iran
- Department of Environmental Health Engineering
| | - Abbas Rezaee
- Department of Environmental Health Engineering
- Faculty of Medical Sciences
- Tarbiat Modares University
- Tehran
- Iran
| | - Mahdi Farzadkia
- Research Center for Environmental Health Technology
- Iran University of Medical Sciences
- Tehran
- Iran
- Department of Environmental Health Engineering
| | - Mitra Gholami
- Research Center for Environmental Health Technology
- Iran University of Medical Sciences
- Tehran
- Iran
- Department of Environmental Health Engineering
| | - Majid Kermani
- Research Center for Environmental Health Technology
- Iran University of Medical Sciences
- Tehran
- Iran
- Department of Environmental Health Engineering
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8
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Li W, Sun Y, Wang H, Wang YN. Improving leachate quality and optimizing CH 4 and N 2O emissions from a pre-aerated semi-aerobic bioreactor landfill using different pre-aeration strategies. CHEMOSPHERE 2018; 209:839-847. [PMID: 30114732 DOI: 10.1016/j.chemosphere.2018.06.148] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 06/11/2018] [Accepted: 06/23/2018] [Indexed: 06/08/2023]
Abstract
Landfill aeration efficiently accelerates municipal solid waste (MSW) stabilization. This method also impacts methane (CH4) and nitrous oxide (N2O) emissions during aeration. In this study, the effects of three pre-aeration strategies on leachate quality variations and CH4 and N2O emissions from three lab-scale pre-aerated semi-aerobic bioreactor landfills, which were filled with MSW, were investigated: low frequency and high frequency intermittent aeration (LIA and HIA) and continuous micro-aeration (CMA). Experimental results showed that these three strategies effectively reduced organic and N-based pollutants concentration in leachate. Compared with intermittent aeration (IA), CMA increased cumulative CH4 emissions (9234.3 mg) and resulted in a longer emission period (95 days). HIA generated the least cumulative CH4 emissions (4297.6 mg) and shortest emission period (65 days) due to organic matter loss during aeration. N2O emissions were present at low levels in early stages for each bioreactor, and then, increased by 1-3 orders of magnitude in the later stages due to low influent carbon-nitrogen ratio. HIA resulted in maximum cumulative N2O emissions (2884.6 mg) and experienced a longer emission period (179 days) compared to CMA (2281.6 mg; 151 days). LIA had the longest N2O emission period (209 days), but had the lowest cumulative N2O emissions (1486.3 mg). CH4 and N2O emissions mainly occurred in the early and later stages of landfill stabilization, respectively. Therefore, the study proposes an optimized pre-aeration strategy for practical landfill aeration management: early CMA may promote rapid organic matter removal and effective CH4 recovery; and late LIA may reduce N2O emissions.
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Affiliation(s)
- Weihua Li
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, 266033, China
| | - Yingjie Sun
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, 266033, China.
| | - Huawei Wang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, 266033, China
| | - Ya-Nan Wang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, 266033, China
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9
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Wu C, Yu M, Huang Q, Ma H, Gao M, Wang Q, Sakai K. Stimulation of methane yield rate from food waste by aerobic pre-treatment. BIORESOURCE TECHNOLOGY 2018; 261:279-287. [PMID: 29677655 DOI: 10.1016/j.biortech.2018.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 03/30/2018] [Accepted: 04/01/2018] [Indexed: 06/08/2023]
Abstract
Aerobic pre-treatment (AP) was applied to enhance methane yield from food waste through anaerobic digestion. Different AP durations (i.e. 2, 5 and 8 days) prior to anaerobic digestion were tested. The results indicated that AP of food waste led to no significant differences (p > 0.05) in methane yield potential (ca. 418 mL/g-VS). However, a suitable AP duration (5 days) increased methane yield rates (ca. 18 mL/d/g-VS; 22.0% higher than the control) by anticipating methane generation and shortening the methanogenic phase via volatile fatty acid reduction and pH increase. Although AP induced chemical oxygen demand loss to some extent (i.e. by 2.6%-9.9%) in the AP stage via aerobic degradation, the methane yield potential could be recovered by enhancing organic matter hydrolysis. Therefore, maximisation of hydrolysis should be used as a basis for determining a suitable AP duration for various types of organic matter.
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Affiliation(s)
- Chuanfu Wu
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China; Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 10083, China
| | - Miao Yu
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
| | - Qiqi Huang
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
| | - Hongzhi Ma
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
| | - Ming Gao
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China; Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 10083, China.
| | - Qunhui Wang
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China; Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 10083, China
| | - Kenji Sakai
- Department of Bioscience and Biotechnology, Faculty of Agriculture Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
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10
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Liu L, Ma J, Xue Q, Shao J, Chen Y, Zeng G. The in situ aeration in an old landfill in China: Multi-wells optimization method and application. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 76:614-620. [PMID: 29545072 DOI: 10.1016/j.wasman.2018.02.041] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 12/07/2017] [Accepted: 02/19/2018] [Indexed: 06/08/2023]
Abstract
The optimization design of well spacing (WS) and aeration rate (AR) is crucial to the in situ aeration system operation in under long-term and high-efficiency conditions. This optimization design aims to transport additional air into landfills and to develop an improved oxygen environment for enhancing aerobic degradation. Given the specific pore structure distribution within landfills, providing sufficient oxygen in all waste bodies in field sites through gas wells is difficult. The design of well distribution also lacks adequate criteria. In this work, the multi-well optimization aeration method (MWOAM) was proposed to select the WS and AR from prediction results that consider gas transport properties by maximizing oxygen storage ratio (OSR) as the key objective threshold. This method was applied to the aeration restoration engineering in Jinkou landfill, which represents the first full-scale application of an aeration project in China, to optimize the operation scheme of the aeration system. Results of the gas concentration monitoring show that the trend of the OSR with aeration time based on the measurement agrees with the prediction. The oxygen and methane contents remain high and low within the landfill during the aeration process, respectively. Moreover, the temperature in the waste body did not exceed the upper limit value. These results suggested that the MWOAM is an effective means of supplying sufficient oxygen content across the landfill body and extend the aeration system operation for the long term. Therefore, this work provides reliable evidence to support the design and operation management of the aeration systems in full-scale landfills.
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Affiliation(s)
- Lei Liu
- State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China; Hubei Key Laboratory of Contaminated Clay Science & Engineering, Wuhan 430071, China.
| | - Jun Ma
- State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100000, China.
| | - Qiang Xue
- State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China; Hubei Key Laboratory of Contaminated Clay Science & Engineering, Wuhan 430071, China.
| | - Jingbang Shao
- Beijing Guohuan Tsinghua Environmental Engineering Design & Research Institute Co., Ltd, China.
| | - Yijun Chen
- State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China; Hubei Key Laboratory of Contaminated Clay Science & Engineering, Wuhan 430071, China
| | - Gang Zeng
- School of Civil Engineering and Architecture, Hubei University of Arts and Science, Xiangyang 441053, China.
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11
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Li W, Sun Y, Bian R, Wang H, Zhang D. N 2O emissions from an intermittently aerated semi-aerobic aged refuse bioreactor: Combined effect of COD and NH 4+-N in influent leachate. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 69:242-249. [PMID: 28811146 DOI: 10.1016/j.wasman.2017.08.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 06/30/2017] [Accepted: 08/09/2017] [Indexed: 06/07/2023]
Abstract
The carbon-nitrogen ratio (COD/NH4+-N) is an important factor affecting nitrification and denitrification in wastewater treatment; this factor also influences nitrous oxide (N2O) emissions. This study investigated two simulated intermittently aerated semi-aerobic aged refuse bioreactors (SAARB) filled with 8-year old aged refuse (AR). The research analyzed how differences in and the combination of influent COD and NH4+-N impact N2O emissions in leachate treatment. Experimental results showed that N2O emissions increased as the influent COD/NH4+-N decreased. The influent COD had a greater effect on N2O emissions than NH4+-N at the same influent ratios of COD/NH4+-N (2.7 and 8.0, respectively). The maximum N2O emission accounted for 8.82±2.65% of the total nitrogen removed from the influent leachate; the maximum level occurred when the COD was 2000mg/L. An analysis of differences in influent carbon sources at the same COD/NH4+-N ratios concluded that the availability of biodegradable carbon substrates (i.e. glucose) is an important factor affecting N2O emissions. At a low influent COD/NH4+-N ratio (2.7), the N2O conversion rate was greater when there were more biodegradable carbon substrates. Although the SAARB included the N2O generation and reduction processes, N2O reduction mainly occurred later in the process, after leachate recirculation. The maximum N2O emission rate occurred in the first hour of single-period (24h) experiments, as leachate contacted the surface AR. In practical SAARB applications, N2O emissions may be reduced by measures such as reducing the initial recirculation loading of NH4+-N substrates, adding a later supplement of biodegradable carbon substrates, and/or prolonging hydraulic retention time (HRT) of influent leachate.
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Affiliation(s)
- Weihua Li
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, PR China
| | - Yingjie Sun
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, PR China.
| | - Rongxing Bian
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Huawei Wang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, PR China
| | - Dalei Zhang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, PR China
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