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Xiang Y, Lan J, Dong Y, Zhou M, Hou H, Huang BT. Pollution control performance of solidified nickel-cobalt tailings on site: Bioavailability of heavy metals and microbial response. JOURNAL OF HAZARDOUS MATERIALS 2024; 471:134295. [PMID: 38631253 DOI: 10.1016/j.jhazmat.2024.134295] [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: 01/15/2024] [Revised: 04/10/2024] [Accepted: 04/10/2024] [Indexed: 04/19/2024]
Abstract
There has been increasing attention given to nickel-cobalt tailings (NCT), which pose a risk of heavy metal pollution in the field. In this study, on site tests and sampling analysis were conducted to assess the physical and chemical characteristics, heavy metal toxicity, and microbial diversity of the original NCT, solidified NCT, and the surrounding soil. The research results show that the potential heavy metal pollution species in NCT are mainly Ni, Co, Mn, and Cu. Simultaneous solidification and passivation of heavy metals in NCT were achieved, resulting in a reduction in biological toxicity and a fivefold increase in seed germination rate. The compressive strength of the original tailings was increased by 20 times after solidification. The microbial diversity test showed that the abundance of microbial community in the original NCT was low and the population was monotonous. This study demonstrates, for the first time, that the use of NCT for solidification in ponds can effectively solidification of heavy metals, reduce biological toxicity, and promote microorganism diversity in mining areas (tended to the microbial ecosystem in the surrounding soil). Indeed, this study provides a new perspective for the environmental remediation of metal tailings.
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Affiliation(s)
- Yuwei Xiang
- School of Resource and Environmental Sciences, Wuhan University, 430072, China.
| | - Jirong Lan
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
| | - Yiqie Dong
- School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430023, China.
| | - Min Zhou
- School of Resource and Environmental Sciences, Wuhan University, 430072, China
| | - Haobo Hou
- School of Resource and Environmental Sciences, Wuhan University, 430072, China.
| | - Bo-Tao Huang
- Institute of Advanced Engineering Structures, Zhejiang University, Hangzhou, China.
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2
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He ZH, Ni YQ, Shi JY, Rong H, Tao HY, Jamal AS. Upcycling textile sludge into magnesium oxychloride cement: Physical properties, microstructure, and leaching behavior. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 924:171416. [PMID: 38447715 DOI: 10.1016/j.scitotenv.2024.171416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 02/04/2024] [Accepted: 02/29/2024] [Indexed: 03/08/2024]
Abstract
Textile sludge is a by-product produced during the wastewater treatment process in the textile printing and dyeing industry. Textile sludge is rich in heavy metal elements, which makes it a potential risk to the surrounding environment. This study designs a magnesium oxychloride cement (MOC) components to solidify harmful substances in textile sludge and studies the influence of textile sludge ash (TSA) on the mechanical properties and microstructure of MOC samples. The results indicated that adding 5 %-20 % TSA is beneficial for increasing the compressive strength of air-cured MOC paste and improving its water resistance. Meanwhile, the MOC sample shows volume expansion in 168 h, which is related to the further hydration of residual MgO. Incorporating 10 %-20 % TSA substantially increased the volume expansion ratio of the mixture compared to plain MOC sample. In addition, the porosity of TSA-modified MOC after water curing did not change significantly compared to the sample before water curing, while the pore structure of plain MOC after water curing significantly coarsened. This is mainly because TSA reacts with MOC and generates Mg-Al-Cl-Si-H and Mg-Cl-Si-H gels, consequently improving the water stability of MOC sample. At the nanoscale, the 3/5-phase crystal and unreacted MgO content in the 15 % TSA-modified MOC sample is relatively reduced by 7.79 % and 25 %, respectively, compared to the plain sample, but the 13 % gel phase is detected. In addition, the MOC component can effectively solidify heavy metal elements in textile sludge. For the leachate of 20 % TSA-modified MOC paste, the Ni element is not detected, and its solidifying effect on heavy elements such as Zn and Mn exceeded 99 %.
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Affiliation(s)
- Zhi-Hai He
- College of Civil Engineering, Shaoxing University, Shaoxing 312000, China; Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province, Shaoxing 312000, China
| | - Ya-Qian Ni
- College of Civil Engineering, Shaoxing University, Shaoxing 312000, China
| | - Jin-Yan Shi
- School of Civil Engineering, Central South University, Changsha 410075, China.
| | - Hui Rong
- School of Materials Science and Engineering, Tianjin Chengjian University, Tianjin 300384, China
| | - Hong-Yu Tao
- Yuanpei College, Shaoxing University, Shaoxing 312000, China
| | - Ahmed Salah Jamal
- Civil Engineering Department, Tishk International University, Erbil 44001, Iraq
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3
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Tong H, Shi D, Huang J, Xu S, Fu K, Wen X, Xie H, Liu J, Cai H, Xu X. Resource utilization of MSWI fly ash supporting TiO 2/BiOCl nanocomposite for enhanced photocatalytic degradation of sodium isopropyl xanthate: Mechanism and performance evaluation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 359:120987. [PMID: 38692029 DOI: 10.1016/j.jenvman.2024.120987] [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: 02/11/2024] [Revised: 03/24/2024] [Accepted: 04/20/2024] [Indexed: 05/03/2024]
Abstract
The removal of organic pollutants in water environments and the resource utilization of solid waste are two pressing issues around the world. Facing the increasing pollution induced by discharge of mining effluents containing sodium isopropyl xanthate (SIPX), in this work, municipal solid waste incineration fly ash (MSWI FA) was pretreated by hydrothermal method to produce stabilized FA, which was then innovatively used as support for the construction of FA/TiO2/BiOCl nanocomposite (FTB) with promoted photocatalytic activity under visible light and natural sunlight. When the content of FA was 20 wt% and the mass ratio of TiO2 to BiOCl was 4:6, a remarkable performance for the optimal FTB (20-FTB-2) was achieved. Characterizations demonstrated that TiO2 and BiOCl uniformly dispersed on FA contributing to high surface area and broad light adsorption of FTB, which exhibits excellent adsorption capacity and light response ability. Build in electric field formed in the interface of TiO2/BiOCl heterojunction revealed by density functional theory calculations accelerated the separation of photoinduced e- and h+, leading to high efficiency for SIPX degradation. The synergetic effect combined with adsorption and photocatalytic degradation endowed 20-FTB-2 superior SIPX removal efficiency over 99% within 30 min under visible light and natural sunlight irradiation. The photocatalytic degradation pathways of SIPX were determined through theoretical calculations and characterizations, and the toxic byproduct CS2 was effectively eliminated through oxidation of •O2-. For 20-FTB-2, reusability of photocatalyst was showed by cycle tests, also the concentrations of main heavy metals (Pb, Zn, Cu, Cr, and Cd) in the liquid phases released during photocatalyst preparation process (< 1 mg/L) and photodegradation process (< 8.5 μg/L) proved the satisfactory stability with low toxicity. This work proposed a novel strategy to develop efficient and stable support-based photocatalysts by utilizing MSWI FA and realize its resource utilization.
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Affiliation(s)
- Haihang Tong
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, 400044, PR China; School of Energy and Environment, City University of Hong Kong, Kowloon Tong, Hong Kong, 999077, PR China
| | - Dezhi Shi
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, 400044, PR China.
| | - Jie Huang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, 400044, PR China
| | - Shuo Xu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, 400044, PR China
| | - Kun Fu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, 400044, PR China
| | - Xianyi Wen
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, 400044, PR China
| | - Hui Xie
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, 400044, PR China
| | - Jiayu Liu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, 400044, PR China
| | - Huayi Cai
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, 400044, PR China
| | - Xiaoyi Xu
- College of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215000, PR China
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Liu R, Liu S, Sun S, Cao X, Lin J, Peng J, Ji F, Ma R. Medical waste incineration fly ash-based magnesium potassium phosphate cement: Calcium-reinforced chlorine solidification/stabilization mechanism and optimized carbon reduction process strategy. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 357:120749. [PMID: 38552517 DOI: 10.1016/j.jenvman.2024.120749] [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: 11/30/2023] [Revised: 02/28/2024] [Accepted: 03/20/2024] [Indexed: 04/14/2024]
Abstract
The traditional solidification/stabilization (S/S) technology, Ordinary Portland Cement (OPC), has been widely criticized due to its poor resistance to chloride and significant carbon emissions. Herein, a S/S strategy based on magnesium potassium phosphate cement (MKPC) was developed for the medical waste incineration fly ash (MFA) disposal, which harmonized the chlorine stabilization rate and potential carbon emissions. The in-situ XRD results indicated that the Cl- was efficiently immobilized in the MKPC system with coexisting Ca2+ by the formation of stable Ca5(PO4)3Cl through direct precipitation or intermediate transformation (the Cl- immobilization rate was up to 77.29%). Additionally, the MFA-based MKPC also demonstrated a compressive strength of up to 39.6 MPa, along with an immobilization rate exceeding 90% for heavy metals. Notably, despite the deterioration of the aforementioned S/S performances with increasing MFA incorporation, the potential carbon emissions associated with the entire S/S process were significantly reduced. According to the Life Cycle Assessment, the potential carbon emissions decreased to 8.35 × 102 kg CO2-eq when the MFA reached the blending equilibrium point (17.68 wt.%), while the Cl- immobilization rate still remained above 65%, achieving an acceptable equilibrium. This work proposes a low-carbon preparation strategy for MKPC that realizes chlorine stabilization, which is instructive for the design of S/S materials.
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Affiliation(s)
- Runjie Liu
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Shiwei Liu
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Shichang Sun
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Xing Cao
- Shenzhen Engineering Lab of Flexible Transparent Conductive Films, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China
| | - Junhao Lin
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Juan Peng
- Shenzhen Environmental Technology Group Co. LTD, Shenzhen, 518010, China
| | - Fei Ji
- Shenzhen Environmental Technology Group Co. LTD, Shenzhen, 518010, China
| | - Rui Ma
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, China.
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Shi D, Liu J, Tong H, Fu K, Salam M, Huang J, Xu S, Wen X, Xie H, Wang P, Cai H, Luo D. Enhancement of catalytic detoxification of polycyclic aromatic hydrocarbons in fly ash from municipal solid waste incineration via magnetic hydroxyapatite-assisted hydrothermal treatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170467. [PMID: 38290685 DOI: 10.1016/j.scitotenv.2024.170467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/01/2024]
Abstract
The emission of carcinogenic, teratogenic, and mutagenic polycyclic aromatic hydrocarbons (PAHs) during municipal solid waste incineration (MSWI) of fly ash (FA) has attracted significant attention. Hydrothermal treatment (HT) has emerged as a practical approach for degrading PAHs during MSWI of FA by utilizing magnetite (Fe3O4) as a catalyst and hydrogen peroxide (H2O2) as an oxidizing agent. In this study, as an alternative to traditional hydroxyapatite (HAP), eggshell-derived magnetic hydroxyapatite (MHAP) was synthesized and applied in the hydrothermal catalytic degradation of PAHs in MSWI FA in an H2O2 system for the first time. The degradation efficiency of the PAHs is influenced not only by H2O2 but also by the choice of hydroxyapatite. Adding HAP or MHAP during hydrothermal treatment with H2O2 substantially reduced the overall PAH concentration and toxicity equivalent quantity (TEQ), superior to that without H2O2. MHAP demonstrated superior catalytic activity compared to HAP in the presence of H2O2 in the hydrothermal system. The hydrothermal detoxification of the PAHs increased with increasing MHAP dosage. By employing 0.5 mol/L H2O2 as the oxidant and 15 wt% MHAP as the catalyst, a total PAH degradation rate of 88.9 % was achieved, with a remarkable TEQ degradation rate of 98.3 %. Notably, the level of 4-6-ring PAHs, particularly benzo(a) pyrene (BaP) and dibenz(a,h)anthracene (DahA), with a TEQ of 1.0, was significantly reduced (by 69.4 % and 46.0 %, respectively). MHAP remained stable during the hydrothermal catalytic process, whereas H2O2 was effectively activated by MHAP and decomposed to produce strongly oxidizing hydroxyl (•OH) under hydrothermal conditions. •OH produced from the decomposition of H2O2 and metals on the surface of MHAP act as catalytically active centers, efficiently converting high-ring PAHs to low-ring PAHs. These findings provide valuable insights and a technological foundation for PAH detoxification in MSWI FA via hydrothermal catalytic oxidation.
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Affiliation(s)
- Dezhi Shi
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, PR China.
| | - Jiayu Liu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, PR China
| | - Haihang Tong
- School of Energy and Environment, City University of Hong Kong, Kowloon Tong, 999077, Hong Kong
| | - Kun Fu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, PR China
| | - Muhammad Salam
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, PR China
| | - Jie Huang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, PR China
| | - Shuo Xu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, PR China
| | - Xianyi Wen
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, PR China
| | - Hui Xie
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, PR China
| | - Pan Wang
- Chongqing Water Resources and Electric Engineering College, Chongqing 402160, PR China.
| | - Huayi Cai
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, PR China
| | - Dan Luo
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, PR China
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Liu Y, Molinari S, Dalconi MC, Valentini L, Bellotto MP, Ferrari G, Pellay R, Rilievo G, Vianello F, Famengo A, Salviulo G, Artioli G. Industrial by-products-derived binders for in-situ remediation of high Pb content pyrite ash: Synergistic use of ground granulated blast furnace slag and steel slag to achieve efficient Pb retention and CO 2 mitigation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 345:123455. [PMID: 38301818 DOI: 10.1016/j.envpol.2024.123455] [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: 07/05/2023] [Revised: 12/19/2023] [Accepted: 01/25/2024] [Indexed: 02/03/2024]
Abstract
Ordinary Portland cement (OPC) is a cost-effective and conventional binder that is widely adopted in brownfield site remediation and redevelopment. However, the substantial carbon dioxide emission during OPC production and the concerns about its undesirable retention capacity for potentially toxic elements strain this strategy. To tackle this objective, we herein tailored four alternative binders (calcium aluminate cement, OPC-activated ground-granulated blast-furnace slag (GGBFS), white-steel-slag activated GGBFS, and alkaline-activated GGBFS) for facilitating immobilization of high Pb content pyrite ash, with the perspectives of enhancing Pb retention and mitigating anthropogenic carbon dioxide emissions. The characterizations revealed that the incorporation of white steel slag efficiently benefits the activity of GGBFS, herein facilitating the hydration products (mainly ettringite and calcium silicate hydrates) precipitation and Pb immobilization. Further, we quantified the cradle-to-gate carbon footprint and cost analysis attributed to each binder-Pb contaminants system, finding that the application of these alternative binders could be pivotal in the envisaged carbon-neutral world if the growth of the OPC-free roadmap continues. The findings suggest that the synergistic use of recycled white steel slag and GGBFS can be proposed as a profitable and sustainable OPC-free candidate to facilitate the management of lead-contaminated brownfield sites. The overall results underscore the potential immobilization mechanisms of Pb in multiple OPC-free/substitution binder systems and highlight the urgent need to bridge the zero-emission insights to sustainable in-situ solidification/stabilization technologies.
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Affiliation(s)
- Yikai Liu
- Department of Geosciences and CIRCe Centre, University of Padua, via G. Gradenigo 6, 35129, Padua, Italy
| | - Simone Molinari
- Department of Geosciences and CIRCe Centre, University of Padua, via G. Gradenigo 6, 35129, Padua, Italy.
| | - Maria Chiara Dalconi
- Department of Geosciences and CIRCe Centre, University of Padua, via G. Gradenigo 6, 35129, Padua, Italy
| | - Luca Valentini
- Department of Geosciences and CIRCe Centre, University of Padua, via G. Gradenigo 6, 35129, Padua, Italy
| | | | | | - Roberto Pellay
- TEVGroup S.r.l., via Romea 8, 30034, Mira, Venice, Italy
| | - Graziano Rilievo
- Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell'Università 16, 35020, Legnaro, Italy
| | - Fabio Vianello
- Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell'Università 16, 35020, Legnaro, Italy
| | - Alessia Famengo
- Istituto di Chimica della Materia Condensata e di Tecnologie per l'Energia, Consiglio Nazionale delle Ricerche, C.so Stati Uniti 4, 35127, Padova, Italy
| | - Gabriella Salviulo
- Department of Geosciences and CIRCe Centre, University of Padua, via G. Gradenigo 6, 35129, Padua, Italy
| | - Gilberto Artioli
- Department of Geosciences and CIRCe Centre, University of Padua, via G. Gradenigo 6, 35129, Padua, Italy
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Jiang H, Yin J, Wei D, Luo X, Ding Y, Xia R. Industrial carbon emission efficiency prediction and carbon emission reduction strategies based on multi-objective particle swarm optimization-backpropagation: A perspective from regional clustering. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167692. [PMID: 37827314 DOI: 10.1016/j.scitotenv.2023.167692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/22/2023] [Accepted: 10/07/2023] [Indexed: 10/14/2023]
Abstract
Against the backdrop of global climate change, industrial carbon emission reduction has become an important pathway to for global low-carbon development. This study constructs a framework of geographic spatial constraints regionalization and multi-objective machine learning to predict future industrial carbon emission efficiency (ICEE) and explore strategies for carbon emission reduction. Firstly, the ICEE of 285 Chinese cities were calculated by the super-efficiency slacks-based measure. Secondly, the cities were classified into four ICEE level regions through the spatially constrained multivariate clustering. Next, the multi-objective particle swarm optimization-BP (MOPSO-BP) model was constructed to predict the future trends of ICEE in the four regions. Finally, the geographical detector and multi-scale geographically weighted regression were employed for exploring driving force and carbon emission reduction strategies in different regions. The results show that most cities had low or medium ICEE, while super efficiency cities were mainly distributed in the east coastal areas. The prediction performance of the MOPSO-BP model for the four regions was better than the ordinary particle swarm optimization-BP and traditional BP model. Except for the Agricultural Production Region, there is considerable room for improving the ICEE of other regions over the next decade. Macroeconomic and microeconomic development have a global effect in promoting regional ICEE improvement, urban construction shows a promoting or inhibiting effect in different regions, and information technology has significant spatial heterogeneity in its influence within each region. The analysis framework developed in the study is a reliable solution for managing and planning ICEE and provides constructive suggestions for future regional low-carbon development.
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Affiliation(s)
- Hongtao Jiang
- Center for China Western Modernization, Guizhou University of Finance and Economics, Guiyang, Guizhou 550025, China; College of Big Data Application and Economic, Guizhou University of Finance and Economics, Guiyang, Guizhou 550025, China; Key Laboratory of Green Fintech, Guiyang 550025, China
| | - Jian Yin
- Center for China Western Modernization, Guizhou University of Finance and Economics, Guiyang, Guizhou 550025, China; College of Big Data Application and Economic, Guizhou University of Finance and Economics, Guiyang, Guizhou 550025, China; Key Laboratory of Green Fintech, Guiyang 550025, China.
| | - Danqi Wei
- College of Big Data Application and Economic, Guizhou University of Finance and Economics, Guiyang, Guizhou 550025, China
| | - Xinyuan Luo
- College of Big Data Application and Economic, Guizhou University of Finance and Economics, Guiyang, Guizhou 550025, China
| | - Yi Ding
- College of Big Data Application and Economic, Guizhou University of Finance and Economics, Guiyang, Guizhou 550025, China
| | - Ruici Xia
- College of Big Data Application and Economic, Guizhou University of Finance and Economics, Guiyang, Guizhou 550025, China
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Liu ZH, Li JQ, Zhang XL, Li HD, Su DP, Liang JW. MSWIFA and cement cooperate in the disposal of soft soil - experimental study on silty sand and silty clay. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:8150-8163. [PMID: 38177644 DOI: 10.1007/s11356-023-31686-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/19/2023] [Indexed: 01/06/2024]
Abstract
Municipal solid waste incineration fly ash (MSWIFA) can be reused as a positive additive to strengthen soft soil. In this study, MSWIFA was initially used as a supplementary solidification material in combination with ordinary Portland cement to prepare fly ash cement-stabilized soil (FACS) with silty sand and silty clay, respectively. The ratio of MWSIFA to total mass was 5%, 10%, and 15%, and the cement content was set as 10% and 15%. The mechanical properties of FACS were evaluated by unconfined compressive strength test. The heavy metal-leaching test was conducted to estimate the environmental risk of FACS. The scanning electron microscope was used to test the micro-structure of FACS. The X-ray diffraction was performed to analyze material composition of FACS. The result indicates that the collaborative solidification of soft soil with MSWIFA and cement is feasible. Regarding the silty clay, the FA had positive effects on the silty clay in the service age (between 50 and 100% with 15% MSWIFA), as the MSWIFA reformulated the initial silty clay structure, resulting in interconnection and pore fill between particles. It can be founded that C-S-H and ettringite are the main products of MSWIFA and cement hydration, which are formed by the hydration of C3S and C2S. Regarding the silty sand, the MSWIFA decreased the peak strength (between 35 and 48% with 15% MSWIFA) but increased the ductility of the stabilized cement. Under the same mix proportions, the leaching toxicities of Zn and Pb in FACS of silty clay were obviously lower than were those of silty sand. Generally, the leaching concentrations of tested metals under all the mix proportions were well below the limit value set by GB 18598-2019 for hazardous waste landfill. Thus, the reuse of MSWIFA in cement-stabilized soil would be one of the effective methods in soft soil treatment and solid waste reduction.
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Affiliation(s)
- Zong-Hui Liu
- Guangxi Key Laboratory of Disaster Prevention and Engineering Safety, College of Civil Engineering and Architecture, State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, Guangxi University, Nanning, 530004, China
| | - Jia-Qi Li
- Guangxi Key Laboratory of Disaster Prevention and Engineering Safety, College of Civil Engineering and Architecture, State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, Guangxi University, Nanning, 530004, China
| | - Xiao-Lei Zhang
- Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Department of Geotechnical Engineering, Tongji University, Shanghai, 200092, China.
| | - Hao-Dong Li
- Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Department of Geotechnical Engineering, Tongji University, Shanghai, 200092, China
| | - Dong-Po Su
- Guangxi Key Laboratory of Disaster Prevention and Engineering Safety, College of Civil Engineering and Architecture, State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, Guangxi University, Nanning, 530004, China
| | - Jia-Wei Liang
- Guangxi Key Laboratory of Disaster Prevention and Engineering Safety, College of Civil Engineering and Architecture, State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, Guangxi University, Nanning, 530004, China
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