Utilizing municipal solid waste incineration fly ash for mine goaf filling: Preparation, optimization, and heavy metal leaching study

IF 7.7 2区 环境科学与生态学 Q1 ENVIRONMENTAL SCIENCES
Lijuan Su , Siyao Wu , Feng Yu , Wancheng Zhu , Xiangdong Zhang , Bing Liang
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引用次数: 0

Abstract

Municipal solid waste incineration fly ash (MSWI FA) contains many harmful substances, such as heavy metals, which pose a great threat to the ecological environment. Its proper disposal is an urgent environmental problem that needs to be addressed. The large number of goaf areas in China's mines provides a new approach for MSWI FA treatment. Scientifically processed MSWI FA can be used for goaf filling; this reduces the stockpile of MSWI FA and improves the safety of mine goaf areas. In this study, paste backfill was prepared using MSWI FA and slag as cementitious materials and coal gangue as aggregates under the composite excitation of sodium hydroxide and water glass. The optimal mix ratio was determined using response surface methodology, and the leaching trend of the heavy metal ions inside the material and the micro mechanism of strength formation were studied. Molecular dynamics simulations were used to further examine the leaching pathways of the heavy metal ions. The experimental research showed that the optimal mix proportions of the backfill were 81.65%, 3.67% and 52.27% for the mass concentration, aggregate-to-cement ratio and fine gangue ratio, respectively. The main polymerization products were C-(A)-S-H and N-A-S-H silicate gel, and small amounts of ettringite (AFt), calcium aluminate chloride (3CaO • Al2O3 • 3CaCl2 • 30H2O) and CaCO3 were generated. Through Materials Studio (MS) software, the leaching pathway of the heavy metal ions in the backfill and the adsorption performance between the ions were examined, and the influence of the C-A-S-H gel on the leaching rates of the heavy metal ions of Pb2+, Cr3+, and Cd2+ was explored. The leaching rate was ranked as Pb2+>Cr3+>Cd2+. In this study, a pollution-free and structurally stable mine paste backfill material was prepared using MSWI FA solid waste.
利用生活垃圾焚烧飞灰充填矿山采空区:制备、优化及重金属浸出研究。
城市生活垃圾焚烧飞灰(MSWI FA)中含有重金属等多种有害物质,对生态环境造成极大威胁。它的妥善处理是一个迫切需要解决的环境问题。中国矿山大量的采空区,为MSWI FA处理提供了新的途径。经科学处理的MSWI FA可用于采空区充填;这减少了MSWI FA的库存,提高了采空区的安全性。在氢氧化钠和水玻璃的复合激发下,以MSWI FA和矿渣为胶凝材料,煤矸石为集料制备膏体充填体。采用响应面法确定了最佳配比,并对材料内部重金属离子的浸出趋势和强度形成的微观机理进行了研究。利用分子动力学模拟进一步研究了重金属离子的浸出途径。试验研究表明,充填体质量浓度、骨料灰比和细脉石比的最佳配合比分别为81.65%、3.67%和52.27%。聚合产物主要为C-(A)- s - h和N-A-S-H硅酸盐凝胶,并生成少量钙矾石(AFt)、氯化铝酸钙(3CaO•Al2O3•3CaCl2•30H2O)和CaCO3。通过Materials Studio (MS)软件,考察了重金属离子在充填体中的浸出途径及离子间的吸附性能,探讨了C-A-S-H凝胶对重金属离子Pb2+、Cr3+、Cd2+浸出速率的影响。浸出率依次为Pb2+>Cr3+>Cd2+。本研究利用MSWI FA固体废弃物制备了一种无污染、结构稳定的矿山膏体充填材料。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
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来源期刊
Environmental Research
Environmental Research 环境科学-公共卫生、环境卫生与职业卫生
CiteScore
12.60
自引率
8.40%
发文量
2480
审稿时长
4.7 months
期刊介绍: The Environmental Research journal presents a broad range of interdisciplinary research, focused on addressing worldwide environmental concerns and featuring innovative findings. Our publication strives to explore relevant anthropogenic issues across various environmental sectors, showcasing practical applications in real-life settings.
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