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Hu Y, Feng Y, Yao L, Wu C, Chen M, Zhang H, Li Q. Destabilization mechanisms of Semi-aerobic aged refuse biofilters under harsh treatment conditions: Evidence from fluorescence and microbial characteristics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174436. [PMID: 38964403 DOI: 10.1016/j.scitotenv.2024.174436] [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: 03/18/2024] [Revised: 06/28/2024] [Accepted: 06/30/2024] [Indexed: 07/06/2024]
Abstract
Semi-aerobic aged refuse biofilters (SAARB) are commonly-used biotechnologies for treating landfill leachate. In actual operation, SAARB often faces harsh conditions characterized by high concentrations of chemical oxygen demand (COD) and Cl-, as well as a low carbon-to-nitrogen ratio (C/N), which can disrupt the microbial community within SAARB, leading to operational instability. Maintaining the stable operation of SAARB is crucial for the efficient treatment of landfill leachate. However, the destabilization mechanism of SAARB under harsh conditions remains unclear. To address this, the study simulated the operation of SAARB under three harsh conditions, namely, high COD loading (H-COD), high chloride ion (Cl-) concentration environment (H-Cl-), and low C/N ratio environment (L-C/N). The aim is to reveal the destabilization mechanism of SAARB under harsh conditions by analyzing the fluorescence characteristics of effluent DOM and the microbial community in aged refuse. The results indicate that three harsh conditions have different effects on SAARB. H-COD leads to the accumulation of proteins; H-Cl- impedes the reduction of nitrite nitrogen; L-C/N inhibits the degradation of humic substances. These outcomes are attributed to the specific effects of different factors on the microbial communities in different zones of SAARB. H-COD and L-C/N mainly affect the degradation of organic matter in aerobic zone, while H-Cl- primarily impedes the denitrification process in the anaerobic zone. The abnormal enrichment of Corynebacterium, Castellaniella, and Sporosarcina can indicate the instability of SAARB under three harsh conditions, respectively. To maintain the steady operation of SAARB, targeted acclimation of the microbial community in SAARB should be carried out to cope with potentially harsh operating conditions. Besides, timely mitigation of loads should be implemented when instability characteristics emerge, and carbon sources and electron donors should be provided to restore treatment performance effectively.
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Affiliation(s)
- Yuansi Hu
- School of Environmental Science an Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Yuanyuan Feng
- School of Environmental Science an Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Li Yao
- School of Environmental Science an Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Chuanwei Wu
- Three Gorges Group Sichuan Energy Investment Co., Ltd., Chengdu 610000, China
| | - Mengli Chen
- School of Environmental Science an Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Han Zhang
- School of Environmental Science an Engineering, Southwest Jiaotong University, Chengdu 611756, China.
| | - Qibin Li
- School of Environmental Science an Engineering, Southwest Jiaotong University, Chengdu 611756, China.
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Bai X, Yang G. Treatment of refractory organics in biologically treated landfill leachate by a zero valent iron enhanced Peroxone process: Degradation efficiency and mechanism study. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2023; 41:594-607. [PMID: 36169147 DOI: 10.1177/0734242x221126390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A zero valent iron (ZVI) enhanced Peroxone process (ZVI/Peroxone) was used to treat biologically treated landfill leachate (BTL). The treatment efficiency of the ZVI/Peroxone process was compared to single (ZVI, O3 and H2O2) and dual (ZVI/H2O2, Fe0/O3 and Peroxone) processes. The results showed that ZVI can greatly enhance the treatment capability of the Peroxone process, and the color number (CN), absorbance at 254 nm (UV254), and total organic carbon (TOC) removal efficiencies were 98.82, 84.30 and 66.38%, respectively. In the ZVI/Peroxone process, higher O3 and ZVI dosages improved organics removal, and H2O2 could promote organics removal within a certain dosage range. However, too much H2O2 decreased treatment efficiency. The best treatment performance by the ZVI/Peroxone process was obtained under acidic conditions. The three-dimensional excitation and emission matrix analysis showed that BTL mainly contained two fluorescent substances, which were fulvic-like substances in the ultraviolet region (Ex/Em = 235-255 nm/410-450 nm) and fulvic-like substances in the visible light region (Ex/Em = 310-360 nm/370-450 nm). Fluorescent substances could be substantially degraded by the ZVI/Peroxone process during the early stages of the reaction. An analysis of ZVI morphology and element valency changes showed that the micro Fe0 particles used in this study remained highly reactive during the process. The ZVI enhanced the homogenous Fenton, heterogeneous Fenton, and coagulation-flocculation effects during the Peroxone process.
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Affiliation(s)
- Xue Bai
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China
- Southwest Municipal Engineering Design & Research Institute of China, Chengdu, China
| | - Guangxu Yang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China
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3
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Mu S, Chen X, Song B, Wu C, Li Q. Enhanced performance and mechanism of the combined process of ozonation and a semiaerobic aged refuse biofilter for mature landfill leachate treatment. CHEMOSPHERE 2022; 308:136432. [PMID: 36115471 DOI: 10.1016/j.chemosphere.2022.136432] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/01/2022] [Accepted: 09/09/2022] [Indexed: 06/15/2023]
Abstract
A semiaerobic aged refuse biofilter (SAARB) can effectively treat mature landfill leachate (ML), but prolonged operation can lead to the enrichment of pollutants in the biofilter, resulting in severely degraded treatment performance. In this study, we constructed a combination process of ozonation and a SAARB to treat ML based on the principles of selective oxidation of aromatic organics by ozone and the preference of microorganisms for ozonation products. The results showed that the removal of organic and nitrogen pollutants became extremely poor after long-term treatment of ML using the SAARB alone. The decrease of chemical oxygen demand (COD), light absorbance at 254 nm (UV254), NH4+, and total nitrogen (TN) improved significantly after recirculating the ozonated ML effluent (OLE) into the SAARB, and the removal extents increased significantly to 63.59% (COD), 26.14% (UV254), 92.85% (NH4+), and 52.04% (TN), respectively. In addition, the recirculation of OLE enhanced the complete denitrification and tolerance to high NH4+ loading by the SAARB. An analysis of the community composition of 16S_bacteria and ammonia oxidation bacteria (AOB) showed that long-term treatment of ML using the SAARB alone had difficulty enriching the dominant functional bacteria. In the OLE recirculation stage, environmental factors-such as influent organic matter species and concentration, nitrogen pollutant concentration, and pH-were changed to influence the community composition of 16S_bacteria and AOB and enrich functional bacteria (e.g., Truepera, Luteibacter, and Nitrosospira). Therefore, ozonation combined with a SAARB can remove organic and nitrogen pollutants more effectively. In particular, this can be used to solve the problem of inefficient total nitrogen removal using the SAARB alone. This study provides a theoretical reference for the efficient and stable operation of biological processes when treating ML.
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Affiliation(s)
- Shiqi Mu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Xinglong Chen
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Bowen Song
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Chuanwei Wu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Qibin Li
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China.
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Chu YX, Wang J, Jiang L, Tian G, He R. Intermittent aeration reducing N 2O emissions from bioreactor landfills with gas-water joint regulation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 139:309-320. [PMID: 34999438 DOI: 10.1016/j.wasman.2021.12.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/04/2021] [Accepted: 12/29/2021] [Indexed: 06/14/2023]
Abstract
Landfills are important emission sources of atmospheric N2O, especially bioreactor landfills with leachate recirculation. In this study, N2O emissions were characterized in four bioreactor landfills with different ventilation methods, including intermittent (2-h aeration per 12 h or 4 h/d in continuous) and continuous aeration (20 h/d), in comparison to a traditional landfill without aeration. During the experiment, the N2O emissions from the landfill reactors with intermittent aeration were 7.48 and 7.15 mg, accounting for only 20.8% and 19.9% of those with continuous aeration, respectively. Continuous aeration was more favorable for the biodegradation of organic matter than intermittent aeration in the landfilled waste and leachate. Intermittent and continuous aeration could both effectively remove total nitrogen (TN) and NH4+-N with removal efficiencies above 64% in the leachate. In the experimental landfill reactors with gas-water joint regulation, the proportion of N2O-N to TN loss ranged from 0.02% to 0.75%. Luteimonas, Pseudomonas, Thauera, Pusillimonas and Comamonas were the dominant denitrifying bacteria in the landfill reactors. The denitrifying bacterial community in the landfilled waste was closely related to its degree of stabilization and nitrogenous compound concentrations in the landfilled waste and leachate. The NO3--N and NO2--N concentrations of leachate were the most important environmental factors affecting the succession of nirS-type and nirK-type denitrifying microbial communities in the landfilled waste. These findings indicated that intermittent aeration was an economical and effective way to accelerate the stabilization of landfilled waste and reduce the pollutants in leachate and N2O emissions during landfill mining and reclamation.
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Affiliation(s)
- Yi-Xuan Chu
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Jing Wang
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Lei Jiang
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China
| | - Guangming Tian
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Ruo He
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China; College of Environmental and Resource Science, Zhejiang University, Hangzhou 310058, China.
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Hu Y, Gu Z, He J, Li Q. Novel strategy for controlling colloidal instability during the flocculation pretreatment of landfill leachate. CHEMOSPHERE 2022; 287:132051. [PMID: 34523455 DOI: 10.1016/j.chemosphere.2021.132051] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/10/2021] [Accepted: 08/25/2021] [Indexed: 06/13/2023]
Abstract
Flocculation is an economical and effective pretreatment technology for landfill leachate. An iron salt flocculant is often used in landfill leachate pretreatment, but the flocs that are formed are affected by the operation sequence, which subsquently influences flocculation. This study selected three representative landfill leachates (i.e., mature landfill leachate (MLL), biologically treated landfill leachate (BTL), and nanofiltration concentrate leachate (NFCL)). The effect of different operation modes on the removal of organic matter from landfill leachate by flocculation was studied, and a strategy to control colloidal instability is put forward. The results revealed that adjusting the pH value to 9 using NaOH changes the zeta potential of leachate when the leachate and sludge are not separated, which affects electric neutralization in flocculation and colloidal stability. Furthermore, a part of the collected organic matter is released to the leachate again, leading to a decrease in the flocculation pretreatment effect. In this improved flocculation process, the leachate and sludge are first separated, and the pH value of the system is then adjusted to 9. The effect of OH- on electric neutralization is avoided and the remaining Fe3+ can further remove organic matter from leachates. Finally, the UV254 removal efficiencies of MLL, BTL, and NFCL increased by 20.38%, 28.67%, and 22.67%, respectively. In a full-scale application, i.e., an NFCL treatment facility, the UV254 removal efficiency during long-term operation reached 87.50%. Therefore, the colloid instability control strategy this study proposes can provide theoretical and engineering references for the flocculation pretreatment of landfill leachate.
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Affiliation(s)
- Yuansi Hu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, China
| | - Zhepei Gu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, China
| | - Junjie He
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, China
| | - Qibin Li
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, China.
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Hu Y. A microwave radiation-enhanced Fe-C/persulfate system for the treatment of refractory organic matter from biologically treated landfill leachate. RSC Adv 2021; 11:29620-29631. [PMID: 35479523 PMCID: PMC9040904 DOI: 10.1039/d1ra04995j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/11/2021] [Indexed: 01/13/2023] Open
Abstract
In this study, a microwave (MW) radiation enhanced Fe-C/PS system was used to treat refractory organic matter in biologically-treated landfill leachate. The effects of important influencing factors on the refractory organic matter in biologically treated landfill leachate were explored, and the main reactive oxygen species produced in the system were verified. The mechanism by which humus was degraded was investigated by analyzing effectiveness of organics removal in different systems, and comparative analysis was conducted on the Fe-C materials before and after the reaction. The results showed that degradation capacity and reaction rate of the system could be improved with an increase in the Fe-C/PS dosage and MW power, while initial acidic conditions were also conducive to the degradation of organic matter. Under the conditions of an Fe-C of 1 g L-1, PS dosage of 30 mM, MW power of 240 W, and reaction time of 10 min, the UV254, TOC, and CN removal efficiencies were 51.48%, 94.56%, and 51.59%, respectively. In the MW/Fe-C/PS system, a large amount of and a small amount of ˙OH were generated by the thermal activation of PS to remove organic matter. The removal efficiency of organic matter could be further improved via the homogeneous catalytic oxidation and heterogeneous adsorption catalytic oxidation of Fe-C materials. In addition, the MW/Fe-C/PS system was effective for removing refractory organic matter from the leachates from four typical treatment systems: DTRO, SAARB, MBR, and NF. The MW/Fe-C/PS system has the potential to be widely applied for the treatment of landfill leachate.
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Affiliation(s)
- Yuansi Hu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University Chengdu 611756 China
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7
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Zhang X, Wang J, Bao S, Zhang X. Impact of internal conditions on the gas flow path in semi-aerobic landfill reactors. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 770:144673. [PMID: 33515880 DOI: 10.1016/j.scitotenv.2020.144673] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/29/2020] [Accepted: 12/18/2020] [Indexed: 06/12/2023]
Abstract
Despite the continuous development of waste disposal technology, landfill remains a significant means of municipal solid waste disposal around the world. Accelerating the process of waste stabilisation has become a pressing problem. In this study, four indoor landfill reactors were set up. Reactors A and C were semi-aerobic landfills, and in reactors B and D the gas vents were disconnected from the leachate collection pipes. Kitchen waste was the main ingredient of the sample waste (55.46%). The void fractions of reactors C and D were decreased by adding extra gravel. The void fractions were 32.82% and 33.27% in reactors A and B, respectively, whereas those in reactors C and D were about 6% lower. The temperatures of reactors A and B were higher than those of reactors C and D. The temperature peak in reactor A occurred earlier than that in Reactor B. The temperature and gas concentration measurements confirmed that not all the air was discharged directly through the gas vent, and some air passed horizontally through the waste layer of the reactor. It was finally showed that the void fraction and connections in the pipelines inside the landfill reactor affected the gas flow path.
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Affiliation(s)
- Xin Zhang
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, No.7989, Weixing Road, Changchun 130022, PR China
| | - Jiahui Wang
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, No.7989, Weixing Road, Changchun 130022, PR China
| | - Siqi Bao
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, No.7989, Weixing Road, Changchun 130022, PR China
| | - Xinyan Zhang
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, No.7989, Weixing Road, Changchun 130022, PR China.
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Xiang Y, Chen Y, Luo S, Zou J, Zhang A. Degradation of recalcitrant organic matter in SAARB leachate by a combined process of coagulation and catalytic ozonation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:40219-40228. [PMID: 32661974 DOI: 10.1007/s11356-020-08292-4] [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: 10/12/2019] [Accepted: 03/02/2020] [Indexed: 06/11/2023]
Abstract
A combined coagulation and γ-Al2O3 catalytic ozonation process was used to treat semi-aerobic aged refuse biofilter (SAARB) effluent from treating mature landfill leachate. First, the coagulant providing the best pretreatment performance was selected. Then, the coagulated SAARB leachate was further treated in an optimized γ-Al2O3-catalyzed ozonation process. Characteristics of the γ-Al2O3-catalyzed ozonation process were determined, and a reaction mechanism was proposed. FeCl3 provided the best treatment efficiency (chemical oxygen demand (COD) removal of 65.8%, absorbance at 254 nm (UV254) removal of 68.55%, and color number (CN) removal of 79.4%). Under optimized O3 dosage (18.92 mg/min) and γ-Al2O3 dosage (10 g/L), efficiencies of removing COD, UV254, and CN were 54.3%, 82.9%, and 95.9%, respectively, at 30 min. In addition, spectral analysis indicated that fulvic-like substances in ultraviolet and visible regions were effectively degraded in the γ-Al2O3-O3 process and some smaller organic products were produced. Characterization of γ-Al2O3 showed that γ-Al2O3 was relative stable; its morphology and constituent elements did not change much after reaction. In addition, ozonation capacity was enhanced by heterogeneous catalytic effects of γ-Al2O3. The combined coagulation and γ-Al2O3 catalytic ozonation process was proven to be an efficient treatment method for removing bio-refractory organic matter contained in SAARB leachate.
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Affiliation(s)
- Yan Xiang
- Chengdu Textile College, Chengdu, 611731, China
| | - Yaping Chen
- Sichuan Academy of Eco-Environmental Science, Chengdu, 610041, China.
| | - Siqiang Luo
- Sichuan Province Environmental Protection Technology Engineering, Chengdu, 610041, China
| | - Junliang Zou
- Sichuan Province Environmental Protection Technology Engineering, Chengdu, 610041, China
| | - Aiping Zhang
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu, 610068, China.
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Chen W, He C, Gu Z, Wang F, Li Q. Molecular-level insights into the transformation mechanism for refractory organics in landfill leachate when using a combined semi-aerobic aged refuse biofilter and chemical oxidation process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 741:140502. [PMID: 32887006 DOI: 10.1016/j.scitotenv.2020.140502] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 06/11/2023]
Abstract
Landfill leachate contains high concentrations of complex organic matter (OM) that can severely impact the ecological environment. If landfill leachate is to be treated using a combined "biological + advanced treatment" process, the molecular information of OM must be investigated to optimize the operation parameters of the combined process and maximize the removal of organic pollutants. This study applied ultra-high resolution mass spectroscopy to investigate the degradation and transformation characteristics of refractory OM in mature landfill leachate at the molecular level (m/z = 150-800) during biological treatment (i.e., semi-aerobic aged refuse biofilter, SAARB) and subsequent chemical oxidation (i.e., the Fenton process and ozonation). After SAARB treatment, the polycyclic aromatics (aromatic index, AI > 0.66) and polyphenol (0.66 ≥ AI > 0.50) contents increased, and the highly unsaturated phenolic compounds (AI ≤ 0.50 and H/C < 1.5), which have a high bioavailability, were mostly removed. Compared with raw leachate, SAARB effluent (i.e., SAARB leachate) contained fewer organics with short carbon chains, more organics with long carbon chains, an elevated condensation degree for organics and, thus, a considerably reduced biodegradability. Although both the Fenton and ozonation processes could remove many of the polycyclic aromatics and polyphenols, ozone produced considerable amounts of aliphatic compounds with high bioavailability. Compared to ozonation, the Fenton process utilized the hydroxyl radical to non-selectively react with OM and produced better mineralization results.
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Affiliation(s)
- Weiming Chen
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Chen He
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
| | - Zhepei Gu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Fan Wang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China
| | - Qibin Li
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China.
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Pan X, Chen M, Wang F, Li Q. Effect of biochar addition on the removal of organic and nitrogen pollutants from leachate treated with a semi-aerobic aged refuse biofilter. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2020; 38:1176-1184. [PMID: 32964808 DOI: 10.1177/0734242x20957411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The effect of biochar on the removal of organic and nitrogen contaminants from leachate in a semi-aerobic aged refuse biofilter (SAARB) was investigated. A preset amount of biochar was mixed with the aged refuse to explore the enhancement ability of pollutant removal by characterizing the leachate effluent and gas. The results showed that biochar contributed to the removal of organic and nitrogen pollutants from the leachate and that increasing the amount of biochar added led to higher colour number, chemical oxygen demand, ammonia nitrogen, and total nitrogen removal efficiencies. Furthermore, the addition of biochar significantly increased the removal of large molecule organic pollutants from the leachate. The improved removal of organics was due to the considerable number of surface functional groups and the large surface area of the biochar, which effectively absorbed and removed a significant amount of the organic matter from the leachate. Biochar elevated the dissolved oxygen concentration in the semi-aerobic system, which facilitated the completion of the nitrification reaction. It also promoted denitrification by acting as a supplementary carbon source. The nitrous oxide (N2O) emissions decreased as the amount of biochar added increased. When the biochar proportion reached 3%, the N2O emission was only 1.11% of the original total nitrogen and the di-nitrogen emission was 19.61%. The findings of this study can be used to improve the treatment of leachate using biochar combined with a SAARB.
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Affiliation(s)
- Xuqin Pan
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, China
| | - Maonan Chen
- SWJTU-Leeds Joint School, Southwest Jiaotong University, China
| | - Fan Wang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, China
| | - Qibin Li
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, China
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11
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Shi R, Han Z, Li H, Wang S, Guo N, Zhang Y. Carbon emission and energy potential of a novel spatiotemporally anaerobic/semi-aerobic bioreactor for domestic waste treatment. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 114:115-123. [PMID: 32659684 DOI: 10.1016/j.wasman.2020.06.040] [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: 02/26/2020] [Revised: 06/12/2020] [Accepted: 06/27/2020] [Indexed: 06/11/2023]
Abstract
The biogas generation mechanism and its utilization potential in a novel spatiotemporally anaerobic/semi-aerobic bioreactor (STASAB) system with three activated bioreactors (C1, C2 and C3) was analyzed. Methane generation potential was obtained by measurements and estimation methods with similar values of 23.38 and 27.79 kg CH4/t waste, respectively. CH4 and CO2 production was quickly achieved in the STASAB, and the total amount of CH4 and CO2 was low due to the mixed leachate-recirculation operation process among bioreactors, which were at different stages of operation. The microbial communities in different bioreactors were diverse. The leachate-recirculation operation was a critical parameter to effectively enhance the microbial community structure in the STASAB, which can regulate CH4, CO2 and N2O production with global warming potential of 7.479 kg CO2e/(t·d). The STASAB had higher energy potential of 1.011 kWh/(t·d) compared with that of conventional landfills and sequentially anaerobic/semi-aerobic bioreactors. Moreover, direct electricity production in the STASAB is recommended for energy utilization with 38.38% GHG emission reduction, and with 131.43 million CNY (Chinese Yuan) benefit per year for national rural waste disposal via utilization of biogas from the STASAB for power generation. Hence, the STASAB shows a notable potential for treating domestic waste in rural areas.
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Affiliation(s)
- Rui Shi
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu 610059, China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution (Chengdu University of Technology), Chengdu 610059, China; College of Ecology and Environment (Chengdu University of Technology), Chengdu 610059, China
| | - Zhiyong Han
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu 610059, China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution (Chengdu University of Technology), Chengdu 610059, China; College of Ecology and Environment (Chengdu University of Technology), Chengdu 610059, China.
| | - Hao Li
- College of Ecology and Environment (Chengdu University of Technology), Chengdu 610059, China
| | - Shuangchao Wang
- College of Ecology and Environment (Chengdu University of Technology), Chengdu 610059, China
| | - Nanfei Guo
- College of Ecology and Environment (Chengdu University of Technology), Chengdu 610059, China
| | - Yu Zhang
- College of Ecology and Environment (Chengdu University of Technology), Chengdu 610059, China
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Gu Z, Chen W, Wang F, Li Q. A pilot-scale comparative study of bioreactor landfills for leachate decontamination and municipal solid waste stabilization. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 103:113-121. [PMID: 31869722 DOI: 10.1016/j.wasman.2019.12.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 12/10/2019] [Accepted: 12/15/2019] [Indexed: 06/10/2023]
Abstract
Many studies have sought to optimize operation parameters and enhance the treatment capacity of bioreactor landfills (BL) under ideal laboratory conditions. At pilot scale, conclusions drawn from laboratory-scale experiments will be different due to variations in actual landfill composition and changes in environmental conditions. However, comparative pilot-scale studies of traditional anaerobic landfills (AnL) and BLs are rare. In this study, three pilot-scale landfills, including an AnL, anaerobic BL (AnBL) and semi-aerobic BL (SABL), were monitored to examine the difference in performance at different scales and among types of landfills. Settlement amount followed the order SABL (25.45 cm) > AnBL (18.67 cm) > AnL (14.38 cm). Decomposition of organic matter (i.e., volatile fatty acids) was more rapid in SABL than in the other landfills and no hydrolytic acidification period was observed. Therefore, among the three landfills, SABL entered the methanogenic stage in a much shorter time and MSW stabilization was accelerated due to this landfill's unique combination of aerobic-anoxic-anaerobic ambient. In addition, NH4+-N concentration in leachate from the SABL (~19.96 mg/L) was substantially lower than from AnL (338.28 mg/L) and AnBL (233.22 mg/L), and SABL leachate exhibited the least chloride pollution risk. This study provides theoretical support and strong evidence for using SABLs to treat MSW in practical applications.
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Affiliation(s)
- Zhepei Gu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China
| | - Weiming Chen
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China
| | - Fan Wang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China
| | - Qibin Li
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China.
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13
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Wang F, Luo Y, Ran G, Li Q. Sequential coagulation and Fe 0-O 3/H 2O 2 process for removing recalcitrant organics from semi-aerobic aged refuse biofilter leachate: Treatment efficiency and degradation mechanism. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 699:134371. [PMID: 31522039 DOI: 10.1016/j.scitotenv.2019.134371] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 08/22/2019] [Accepted: 09/08/2019] [Indexed: 06/10/2023]
Abstract
Landfill leachate effluent obtained after semi-aerobic aged refuse biofilter (SAARB) treatment still contains various recalcitrant organics. In this study, a sequential coagulation and Fe0-O3/H2O2 process was developed for treating SAARB leachate. The effects in terms of degradation of recalcitrant organics and the related mechanisms due to the coagulation and Fe0-O3/H2O2 processes were systematically explored and discussed. The results indicated that polymerized ferric sulfate was the most efficient coagulant for treating SAARB leachate where the chemical oxygen demand (COD), UV254, and CN removal efficiencies were 59.60%, 63.22%, and 70.32%, respectively. In the Fe0-O3/H2O2 process under the optimized conditions comprising Fe0 dose = 0.6 g/L, O3 dose = 26.80 mg/min, H2O2 dose = 1.0 mL/L, and reaction time = 20 min, the COD, UV254, and CN removal efficiencies with the coagulated supernatant were 43.39%, 59.47%, and 93.20%, respectively, and the biodegradability (biochemical oxygen demand/COD) improved greatly from 0.06 to 0.34. Analysis of UV-Vis and 3D-EEM spectra indicated that coagulation-resistant substances in the SAARB leachate could be effectively degraded and destroyed by the Fe0-O3/H2O2 process. In the O3/H2O2 environment, Fe0 generated Fe2+ and iron oxides (Fe2O3, Fe3O4, and FeOOH) with homogeneous and heterogeneous catalytic roles against O3/H2O2 to produce reactive oxygen species. Furthermore, Fe(OH)2 and Fe(OH)3 colloids contributed to the removal of organics to some extent via adsorption and precipitation effects. In conclusion, the proposed sequential coagulation and Fe0-O3/H2O2 process is an efficient method for treating recalcitrant organics in SAARB leachates.
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Affiliation(s)
- Fan Wang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Sichuan, Chengdu 611756, China
| | - Yuangfeng Luo
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Sichuan, Chengdu 611756, China
| | - Gang Ran
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Sichuan, Chengdu 611756, China
| | - Qibin Li
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Sichuan, Chengdu 611756, China.
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14
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Luo Z, Chen W, Wen P, Jiang G, Li Q. Impact of leachate recirculation frequency on the conversion of carbon and nitrogen in a semi-aerobic bioreactor landfill. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:13354-13365. [PMID: 30903466 DOI: 10.1007/s11356-019-04817-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 03/07/2019] [Indexed: 06/09/2023]
Abstract
To study the impact of leachate recirculation frequency on the transformation of carbon and nitrogen pollutants in a semi-aerobic bioreactor landfill (SABL), three laboratory-scale SABLs were investigated, each using a different leachate recirculation frequency (daily, once each 3 days, and once each 5 days). Results showed that degradation of total nitrogen (TN), ammonium nitrogen (NH4+-N), chemical oxygen demand (COD), and total organic carbon (TOC) could be described using a quadratic polynomial-compound index model. Degradation rates of TN, NH4+-N, COD, and TOC slightly increased from 0.01795, 0.01814, 0.01451, and 0.01166 day-1 to 0.02054, 0.01903, 0.01488, and 0.01203 day-1, respectively, when the recirculation frequency increased from once per 5 days to once per 3 days. When recirculation frequency was increased to daily, degradation rates of TN, NH4+-N, COD, and TOC significantly increased to 0.03698, 0.02718, 0.02479, and 0.02872 day-1, respectively. Moreover, when recirculation frequency increased from once per 5 days to once per 3 days, the gasification rate of nitrogenous and carbonaceous pollutants was enhanced between 20.38 and 8.17%, respectively. When the leachate recirculation rate further increased to daily, only a small amount of carbonaceous and nitrogenous pollutants was transformed to the liquid phase. Thus, increasing the leachate recirculation frequency in an SABL benefits the removal of carbonaceous and nitrogenous pollutants from the reactor. In addition, the greater is the recirculation frequency, the lower is the residual carbon and nitrogen in the solid phase, and the higher is the gasification rate. A proper recirculation frequency promotes the stabilization of landfill leachate. This study provides a theoretical reference and experimental evidence for accelerating the stabilization of MSW and contributes to the macro-control of landfills.
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Affiliation(s)
- Ziyin Luo
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, China
| | - Weiming Chen
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, China
| | - Peng Wen
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, China
| | - Guobin Jiang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, China
| | - Qibin Li
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, China.
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15
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Feng F, Liu ZG, Song YX, Jiang CK, Chai XL, Tang CJ, Chai LY. The application of aged refuse in nitrification biofilter: Process performance and characterization. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 657:1227-1236. [PMID: 30677889 DOI: 10.1016/j.scitotenv.2018.12.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 10/11/2018] [Accepted: 12/03/2018] [Indexed: 06/09/2023]
Abstract
High adsorption capacity, good biocompatibility and low cost are highly demanded for biofilter used in ammonium-rich wastewater treatment. In this study, we used SEM, BET, XRD and 16S rRNA to document the evidence for good performance in adsorption and biodegradation in aged refuse. Parallel experiment between raw and inert refuse showed ammonium adsorption occurred at the initial week, with the highest ammonium removal efficiency of 90.36%, but saturated during the subsequent long-term operation. Meanwhile, over 6months' operation of an aged refuse biofilter was conducted to confirm that nitrification was the main pathway of ammonium conversion. The maximum nitrogen loading rate could reach up to as high as 1.28kg/m3/d, with ammonium removal efficiency at 99%. Further, high nitrifier biodiversity were detected with 'Nitrosomonas' and 'Nitrospira' in domination in the refuse. However, Nitrospira would outcompete Nitrosomonas under the oxygen limiting condition and resulted in the failure of partial nitrification. The physicochemical and biological analysis show that biodegradation is the main ammonium conversion pathway, which is the critical finding of this work. This investigation would help to accelerate the application of the aged refuse process in ammonium-rich wastewater treatment.
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Affiliation(s)
- Fan Feng
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China
| | - Zhi-Gong Liu
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China
| | - Yu-Xia Song
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China
| | - Chu-Kuan Jiang
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China
| | - Xi-Lin Chai
- The Jiangxi Provincial Collaborative Research Institute for Environmental Protection Industry, Wannian 335500, China
| | - Chong-Jian Tang
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China.
| | - Li-Yuan Chai
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China
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16
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Han Z, Zeng D, Mou Z, Shi G, Zhang Y, Lou Z. A novel spatiotemporally anaerobic/semi-aerobic bioreactor for domestic solid waste treatment in rural areas. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 86:97-105. [PMID: 30902244 DOI: 10.1016/j.wasman.2019.01.034] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/22/2019] [Accepted: 01/22/2019] [Indexed: 06/09/2023]
Abstract
To meet the requirements of domestic solid waste treatment and technological upgrading of bioreactors, a spatiotemporally anaerobic/semi-aerobic bioreactor (STASAB) was designed. The STASAB took full advantages of anaerobic and semi-aerobic bioreactors by the sequential alternation of anaerobic and semi-aerobic operation and by recirculation of mixed leachate from different-stage bioreactors. Results indicated that after the start-up stage, the pH of leachate in the STASAB always remained higher than 6.88, even in the hydrolysis and acidogenesis stage. The maximum total nitrogen concentration in the STASAB was 1461 mg·L-1, which was merely half that of the sequentially anaerobic/semi-aerobic bioreactor (SASAB) and had no adverse effects on the anaerobic process. Nitrogen removal in the STASAB reached 92.3%-95.5% when operated in the semi-aerobic phase and even reached 49.4% when operated in the anaerobic phase. The peak concentration of chemical oxygen demand was much lower and the anaerobic digestion lag time was much shorter in the STASAB than in the SASAB. The period of rapid biogas production in the STASAB was double that of the SASAB, which resulted in a 70% increase in biogas generation. Moreover, leachate could be exhausted by evaporation in just 3-5 months during the semi-aerobic phase. Therefore, the STASAB can eliminate acidogenic and ammonia inhibition during solid waste treatment, enhance the rate and extent of organic waste decomposition, rapidly initiate methanogenesis, enhance methane generation, and achieve zero leachate discharge (excluding rainfall infiltration). The STASAB is an efficient and feasible technique for treating domestic solid waste in rural areas.
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Affiliation(s)
- Zhiyong Han
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu 610059, China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution (Chengdu University of Technology), Chengdu 610059, China; Biogas Institute of Ministry of Agriculture, Chengdu 610041, China.
| | - Dan Zeng
- Science School of Tibet University, Lhasa 850002, China
| | - Zishen Mou
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu 610059, China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution (Chengdu University of Technology), Chengdu 610059, China
| | - Guozhong Shi
- Biogas Institute of Ministry of Agriculture, Chengdu 610041, China
| | - Yu Zhang
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu 610059, China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution (Chengdu University of Technology), Chengdu 610059, China
| | - Ziyang Lou
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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17
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Chen W, Zhang A, Jiang G, Li Q. Transformation and degradation mechanism of landfill leachates in a combined process of SAARB and ozonation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 85:283-294. [PMID: 30803582 DOI: 10.1016/j.wasman.2018.12.038] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 12/24/2018] [Accepted: 12/27/2018] [Indexed: 06/09/2023]
Abstract
Dissolved organic matter (DOM) in mature landfill leachate is significantly different from that in young landfill leachate; the composition of DOM greatly influences both biological treatment and advanced treatment processes. In the present study, the transformation and degradation mechanisms of landfill leachates in a combined semi-aerobic aged refuse biofilter (SAARB) and ozonation process was investigated using organic removal analysis, molecular weight distribution (MWD), 3D-EEM-PARAFAC analysis, UV-Vis spectroscopy, and linear regression. Results revealed that the DOM in mature landfill leachate contained a greater amount of aromatic substances and had higher molecular weight than DOM in young landfill leachate. After the SAARB process, humus contained in the SAARB was discharged with effluent from both mature and young landfill leachate. Due to the differences in composition and structure of organic matter, the COD removal efficiency (17.89%) of SAARB effluent from treating mature landfill leachate (mature SAARB effluent) was much lower than that (45.91%) of SAARB effluent from treating young landfill leachate (young SAARB effluent) under the same operational parameters of the ozonation process. As indicated by PARAFAC analysis, better chemical stability of DOM in mature SAARB effluent resulted in inferior ozone treatment efficiency. Furthermore, the hydrophobicity and the concentration of benzene ring compounds in the mature and young SAARB effluent were reduced significantly by the ozonation process. Therefore, great improvements in the biodegradability of SAARB effluents were achieved in the ozonation process. Overall, the results of this study provide suggestions and guidance for practical applications of these technologies.
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Affiliation(s)
- Weiming Chen
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, PR China
| | - Aiping Zhang
- Key Laboratory of Special Waste Water Treatment, Sichuan Province Higher Education System, College of Chemistry and Material Science, Sichuan Normal University, Chengdu 610068, PR China
| | - Guobin Jiang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, PR China
| | - Qibin Li
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, PR China.
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18
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Liu Q, Li Q, Wang N, Liu D, Zan L, Chang L, Gou X, Wang P. Bioremediation of petroleum-contaminated soil using aged refuse from landfills. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 77:576-585. [PMID: 29754988 DOI: 10.1016/j.wasman.2018.05.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 03/21/2018] [Accepted: 05/05/2018] [Indexed: 06/08/2023]
Abstract
This study explored the effects and mechanisms of petroleum-contaminated soil bioremediation using aged refuse (AR) from landfills. Three treatments of petroleum-contaminated soil (47.28 mg·g-1) amended with AR, sterilized aged refuse (SAR) and petroleum-contaminated soil only (as a control) were tested. During 98 days of incubation, changes in soil physicochemical properties, residual total petroleum hydrocarbon (TPH), biodegradation kinetics, enzyme activities and the microbial community were investigated. The results demonstrated that AR was an effective soil conditioner and biostimulation agent that could comprehensively improve the quality of petroleum-contaminated soil and promote microbial growth, with an 74.64% TPH removal rate, 22.36 day half-life for SAR treatment, compared with the control (half-life: 138.63 days; TPH removal rate: 22.40%). In addition, the petroleum-degrading bacteria isolation results demonstrated that AR was also a petroleum-degrading microbial agent containing abundant microorganisms. AR addition significantly improved both the biotic and abiotic conditions of petroleum-contaminated soil without other additives. The cooperation of conditioner addition, biostimulation and bioaugmentation in AR treatment led to better bioremediation effects (half-life: 13.86 days; TPH removal rate: 89.83%). In conclusion, AR amendment is a cost-effective, easy-to-use method facilitating in situ large-scale application while simultaneously recycling huge amounts of AR from landfills.
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Affiliation(s)
- Qingmei Liu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China.
| | - Qibin Li
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China
| | - Ning Wang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China
| | - Dan Liu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China.
| | - Li Zan
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China
| | - Le Chang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China
| | - Xuemei Gou
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China
| | - Peijin Wang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China
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19
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Zhang A, Chen W, Gu Z, Li Q, Shi G. Mechanism of adsorption of humic acid by modified aged refuse. RSC Adv 2018; 8:33642-33651. [PMID: 35548845 PMCID: PMC9086569 DOI: 10.1039/c8ra05933k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 09/25/2018] [Indexed: 11/21/2022] Open
Abstract
In the present study, aged refuse (AR) was modified to be applied as an adsorbent to remove humic acid from water. The efficiency of humic acid removal by modified aged refuse (MAR) under different preparation conditions (calcination temperature, dose of aged refuse for calcination and holding time) was systematically investigated. Results showed that the optimum preparation conditions are calcination temperature = 700 °C, AR dose for calcination = 25 g, and holding time = 2.0 h. The characteristics of the modified aged refuse obtained under different calcination conditions were determined by Fourier transform infrared, X-ray diffraction and X-ray photoelectron spectroscopy analysis. In addition, the effects of modified aged refuse dose and initial solution pH on adsorption performance were studied. The removal of humic acid increased with higher doses of modified aged refuse, and weak alkaline (initial pH = 8.0) conditions were favorable for humic acid removal. A pseudo-second order model fitted the experimental data well. Moreover, the adsorption isotherms were well described by the Langmuir isotherm model, in which the monolayer surface loading was calculated to be approximately 37 mg g−1. During the adsorption process, the molecular weight, degree of condensation and aromaticity of humic acid were considerably decreased, according to 3D-EEM analysis. MAR as a new type of adsorbent thus provides a potential adsorption method for humic acid. In the present study, aged refuse (AR) was modified to be applied as an adsorbent to remove humic acid from water.![]()
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Affiliation(s)
- Aiping Zhang
- Key Laboratory of Special Wastewater Treatment of Collages of Sichuan Province
- College of Chemistry and Material Science of Sichuan Normal University
- Chengdu 610068
- China
- Laboratory of Development and Application of Rural Renewable Energy
| | - Weiming Chen
- Faculty of Geosciences and Environmental Engineering
- Southwest Jiaotong University
- Chengdu 611756
- China
| | - Zhepei Gu
- Key Laboratory of Special Wastewater Treatment of Collages of Sichuan Province
- College of Chemistry and Material Science of Sichuan Normal University
- Chengdu 610068
- China
| | - Qibin Li
- Key Laboratory of Special Wastewater Treatment of Collages of Sichuan Province
- College of Chemistry and Material Science of Sichuan Normal University
- Chengdu 610068
- China
- Faculty of Geosciences and Environmental Engineering
| | - Guozhong Shi
- Laboratory of Development and Application of Rural Renewable Energy
- Ministry of Agriculture
- Chengdu 610041
- China
- Biogas Institute of Ministry of Agriculture
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He Y, Li D, Zhao Y, Huang M, Zhou G. Assessment and analysis of aged refuse as ammonium-removal media for the treatment of landfill leachate. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2017; 35:1168-1174. [PMID: 28956498 DOI: 10.1177/0734242x17730136] [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] [Indexed: 06/07/2023]
Abstract
This is the first attempt to explore the sustainability of aged refuse as ammonium-removal media. Batch experiments combined with the aged-refuse-based reactor were performed to examine how the adsorption and desorption processes are involved in the ammonia removal via aged refuse media in this research. The results showed that the adsorption of ammonium by aged refuse occurred instantly and the adsorbed ammonium was stable and less exchangeable. The adsorption data fit the Freundlich isotherms well and the n value of 0.1-0.5 indicated that the adsorption of ammonium occurred easily. The maximum adsorbed ammonium occupied less than 10% of the cation exchange capacity in aged-refuse-based reactors owing to the high solid/liquid ratios (50:1-120:1). The synergistic transformations of ammonium within the aged-refuse-based reactor indicated that the cation exchange sites only provide temporary storage of ammonium, and the subsequent nitrification process can be considered the predominant restoration pathway of ammonium adsorption capacity of the reactor. It seems reasonable to assume that there is no expiry for the aged-refuse-based reactor in terms of ammonium removal owing to its bioregeneration via nitrification.
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Affiliation(s)
- Yan He
- 1 Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai, China
| | - Dan Li
- 1 Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai, China
| | - Youcai Zhao
- 2 The State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, China
| | - Minsheng Huang
- 1 Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai, China
| | - Gongming Zhou
- 2 The State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, China
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21
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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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22
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Sun X, Zhang H, Cheng Z, Wang S. Effect of low aeration rate on simultaneous nitrification and denitrification in an intermittent aeration aged refuse bioreactor treating leachate. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 63:410-416. [PMID: 28089204 DOI: 10.1016/j.wasman.2016.12.042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 12/30/2016] [Accepted: 12/30/2016] [Indexed: 06/06/2023]
Abstract
Three intermittent aeration aged refuse bioreactors (ARBs), A, B, and C, with aeration rates of 670, 1340, and 2010L/m3 aged refuse·d in stage 1, and 670, 503, and 335L/m3 aged refuse·d in stage 2 were constructed to evaluate the effect of low aeration rate on leachate treatment by simultaneous nitrification and denitrification (SND). Results show that SND can be achieved and improved by reasonably adjusting the aeration rate of the ARB. In stage 1, the average chemical oxygen demand (COD) removal rates of ARBs A, B, and C were 91%, 92%, and 93%, respectively. The ammonia nitrogen (NH4+-N) removal rate of the three ARBs approached 100%. The total nitrogen (TN) average removal rates were 68%, 59%, and 57%. The average SND efficiency values were 73%, 66%, and 65%. In stage 2, the COD removal rates of ARBs A, B, and C decreased from the original values of 85%, 92%, and 93% to 84%, 81%, and 80%. The NH4+-N removal rate decreased from above 99% to 90%-92% in ARB B and from above 99% to 87%-91% in ARB C. The TN removal rates of ARBs B and C increased to 59% and 53% on day 15 from the initial values of 49% and 43% and were maintained at 49%-61% and 50%-60%. The SND efficiency of ARBs B and C improved, and the average values were 68% and 70% after day 15. These values were higher than the 66% of ARB A during the same period. Comprehensively considering the COD, NH4+-N, TN removal rate, and SND efficiency, the optimal aeration rate of 670L/m3 aged refuse·d is therefore suggested in this study.
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Affiliation(s)
- Xiaojie Sun
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, China; Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin 541004, China.
| | - Hongxia Zhang
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, China; Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin 541004, China
| | - Zhaowen Cheng
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, China; Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin 541004, China
| | - Siming Wang
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, China; Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin 541004, China
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Feng Y, Yi A, Li H, Wang W, Du Y. Ocean bacteria: performance on CODCr and NH4(+)-N removal in landfill leachate treatment. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2015; 71:817-822. [PMID: 25812089 DOI: 10.2166/wst.2015.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An experiment was carried out to investigate the performance of mixed ocean bacteria, isolated from the ocean sediment, on landfill leachate treatment. In this treatment, ocean bacteria were the only constituent added to remove organics and NH(4)(+)-N. Given their considerable influence on wastewater purification, factors such as inoculum, initial pH, processing time and oxygen condition, were directly involved in this research. As indicated by laboratory test results, chemical oxygen demand (CODCr) and NH(4)(+)-N removal could reach 94.45% and 67.87%, respectively, after 3 days of treatment, in conditions of natural pH 6.3 and with the application of oxygen. The volt-ampere characteristics of the bacteria solution verified the redox-active ability of the bacteria in landfill leachate treatment.
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Affiliation(s)
- Yali Feng
- School of Civil and Environment Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Aifei Yi
- School of Civil and Environment Engineering, University of Science and Technology Beijing, Beijing 100083, China; State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China E-mail:
| | - Haoran Li
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China E-mail:
| | - Weida Wang
- School of Civil and Environment Engineering, University of Science and Technology Beijing, Beijing 100083, China; State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China E-mail:
| | - Yunlong Du
- School of Civil and Environment Engineering, University of Science and Technology Beijing, Beijing 100083, China; State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China E-mail:
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Wang YN, Sun YJ, Wang L, Sun XJ, Wu H, Bian RX, Li JJ. N₂O emission from a combined ex-situ nitrification and in-situ denitrification bioreactor landfill. WASTE MANAGEMENT (NEW YORK, N.Y.) 2014; 34:2209-2217. [PMID: 25062936 DOI: 10.1016/j.wasman.2014.06.023] [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: 03/19/2014] [Revised: 06/09/2014] [Accepted: 06/21/2014] [Indexed: 06/03/2023]
Abstract
A combined process comprised of ex-situ nitrification in an aged refuse bioreactor (designated as A bioreactor) and in-situ denitrification in a fresh refuse bioreactor (designated as F bioreactor) was constructed for investigating N2O emission during the stabilization of municipal solid waste (MSW). The results showed that N2O concentration in the F bioreactor varied from undetectable to about 130 ppm, while it was much higher in the A bioreactor with the concentration varying from undetectable to about 900 ppm. The greatly differences of continuous monitoring of N2O emission after leachate cross recirculation in each period were primarily attributed to the stabilization degree of MSW. Moreover, the variation of N2O concentration was closely related to the leachate quality in both bioreactors and it was mainly affected by the COD and COD/TN ratio of leachate from the F bioreactor, as well as the DO, ORP, and NO3(-)-N of leachate from the A bioreactor.
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Affiliation(s)
- Ya-nan Wang
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; School of Environmental and Municipal Engineering, Qingdao Technological University, Qingdao 266033, China
| | - Ying-jie Sun
- School of Environmental and Municipal Engineering, Qingdao Technological University, Qingdao 266033, China.
| | - Lei Wang
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xiao-jie Sun
- College of Environmental Science and Engineering, Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, China
| | - Hao Wu
- Sanlihe Subdistrict Office, Jiaozhou, Qingdao 266033, China
| | - Rong-xing Bian
- School of Environmental and Municipal Engineering, Qingdao Technological University, Qingdao 266033, China
| | - Jing-jing Li
- School of Environmental and Municipal Engineering, Qingdao Technological University, Qingdao 266033, China
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Hassan M, Xie B. Use of aged refuse-based bioreactor/biofilter for landfill leachate treatment. Appl Microbiol Biotechnol 2014; 98:6543-53. [DOI: 10.1007/s00253-014-5813-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 05/01/2014] [Accepted: 05/02/2014] [Indexed: 11/28/2022]
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Wang C, Zhao Y, Xie B, Peng Q, Hassan M, Wang X. Nitrogen removal pathway of anaerobic ammonium oxidation in on-site aged refuse bioreactor. BIORESOURCE TECHNOLOGY 2014; 159:266-271. [PMID: 24657757 DOI: 10.1016/j.biortech.2014.02.093] [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: 12/19/2013] [Revised: 02/19/2014] [Accepted: 02/21/2014] [Indexed: 06/03/2023]
Abstract
The nitrogen removal pathways and nitrogen-related functional genes in on-site three-stage aged refuse bioreactor (ARB) treating landfill leachate were investigated. It was found that on average 90.0% of CODCr, 97.6% of BOD5, 99.3% of NH4(+)-N, and 81.0% of TN were removed with initial CODCr, BOD5, NH4(+)-N, and TN concentrations ranging from 2323 to 2754, 277 to 362, 1237 to 1506, and 1251 to 1580 mg/L, respectively. Meanwhile, the functional genes amoA, nirS and anammox 16S rRNA gene were found to coexist in every bioreactor, and their relative proportions in each bioreactor were closely related to the pollutant removal performance of the corresponding bioreactor, which indicated the coexistence of multiple nitrogen removal pathways in the ARB. Detection of anammox expression proved the presence of the anammox nitrogen removal pathway during the process of recirculating mature leachate to the on-site ARB, which provides important information for nitrogen management in landfills.
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Affiliation(s)
- Chao Wang
- Shanghai Key Lab for Urban Ecological Process and Eco-Restoration, Department of Environmental Science & Technology, East China Normal University, Shanghai 200062, China
| | - Youcai Zhao
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Engineering and Science, Tongji University, Shanghai 200092, China
| | - Bing Xie
- Shanghai Key Lab for Urban Ecological Process and Eco-Restoration, Department of Environmental Science & Technology, East China Normal University, Shanghai 200062, China.
| | - Qing Peng
- Shanghai Key Lab for Urban Ecological Process and Eco-Restoration, Department of Environmental Science & Technology, East China Normal University, Shanghai 200062, China
| | - Muhammad Hassan
- Shanghai Key Lab for Urban Ecological Process and Eco-Restoration, Department of Environmental Science & Technology, East China Normal University, Shanghai 200062, China
| | - Xiaoyuan Wang
- Shanghai Key Lab for Urban Ecological Process and Eco-Restoration, Department of Environmental Science & Technology, East China Normal University, Shanghai 200062, China
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Sun F, Sun B, Li Q, Deng X, Hu J, Wu W. Pilot-scale nitrogen removal from leachate by ex situ nitrification and in situ denitrification in a landfill bioreactor. CHEMOSPHERE 2014; 101:77-85. [PMID: 24397889 DOI: 10.1016/j.chemosphere.2013.12.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Revised: 12/07/2013] [Accepted: 12/10/2013] [Indexed: 06/03/2023]
Abstract
A combined process consisting of ex situ nitrification and in situ denitrification in landfill refuse was studied in pilot scale for nitrogen removal from municipal landfill leachate. The results showed that above 80% of partial nitrification ratio and an average COD loading rate of 1.50 kg m(-3) d(-1) were steadily maintained under DO concentrations of 1.0-1.7 mg L(-1) in the aerobic reactor. Quantitative PCR results indicated that nitrite-oxidizing bacteria being sensitive to DO fluctuations lead to partial nitrification when free ammonia inhibition was weak. Nitrified landfill leachate could be denitrified in the landfill bioreactor with maximum total oxidizing nitrogen removal rate of 67.2 g N t(-1) TSwaste d(-1). Clone and sequencing analysis of denitrifying bacterial nirS gene inferred that heterotrophic denitrifier Azoarcus tolulyticu was the primary nitrogen converter in the landfill bioreactor. The obtained results will provide valuable information for optimizing the design and operation of a landfill bioreactor.
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Affiliation(s)
- Faqian Sun
- Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310058, China
| | - Bin Sun
- Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310058, China
| | - Qian Li
- Ningda Inspection and Technology Co. Ltd., Hangzhou 310004, China
| | - Xiaoya Deng
- Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310058, China
| | - Jian Hu
- Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310058, China
| | - Weixiang Wu
- Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310058, China.
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