Shuguang Zhang , Mingzhi Zhang , Jiangshan Li , Yu Song
{"title":"活化氧化镁改性生物炭炭化固化 Zn2+ 污染土壤的强度特征与微观机理","authors":"Shuguang Zhang , Mingzhi Zhang , Jiangshan Li , Yu Song","doi":"10.1016/j.conbuildmat.2024.138341","DOIUrl":null,"url":null,"abstract":"<div><p>Conventional curing agents are associated with environmental impacts when treating Zn<sup>2+</sup>contaminated soils. To overcome this limitation. In this study, we study a new type of MgO-CSB curing agent. Namely, corn stover biochar is modified with activated MgO. Modification of corn stover biochar using activated MgO, and carbonation curing was adopted to solidify/stabilize the Zn<sup>2+</sup>contaminated soil. The curing efficacy of Zn<sup>2+</sup>contaminated soil under modified mass ratio, Zn<sup>2+</sup> concentration, carbonation time, and curing agent incorporation was investigated. The findings indicate that the optimal adsorption efficiency was attained following the co-pyrolytic modification of activated MgO with corn stover biochar at 700°C. The optimal modified mass ratios for curing were found to be 1:1, 1:2, and 2:1 at Zn<sup>2+</sup> concentrations of 0.1 %, 0.5 %, and 1 %, respectively. At a lower Zn<sup>2+</sup> concentration, peak carbonization intensity is achieved at 0.5 hours, while at a 1 % Zn<sup>2+</sup> concentration, peak intensity is reached at 1 hour. The deformation modulus of the cured soil increases as the curing agent dosage increases and the soil aggregates become denser. SEM results show that: The carbonization and curing reaction products are mainly nesquehonite and Mg (OH)<sub>2</sub>. The internal structural damage of the cured soil was aggravated by the increase in Zn<sup>2+</sup>concentration, and the generation of nesquehonite and Mg (OH)<sub>2</sub> was inhibited; The carbonation time was extended to 1 h and the soil structure stability was enhanced.</p></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"449 ","pages":"Article 138341"},"PeriodicalIF":7.4000,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Strength characteristics and microscopic mechanism of activated MgO-modified biochar carbonization curing Zn2+ polluted soil\",\"authors\":\"Shuguang Zhang , Mingzhi Zhang , Jiangshan Li , Yu Song\",\"doi\":\"10.1016/j.conbuildmat.2024.138341\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Conventional curing agents are associated with environmental impacts when treating Zn<sup>2+</sup>contaminated soils. To overcome this limitation. In this study, we study a new type of MgO-CSB curing agent. Namely, corn stover biochar is modified with activated MgO. Modification of corn stover biochar using activated MgO, and carbonation curing was adopted to solidify/stabilize the Zn<sup>2+</sup>contaminated soil. The curing efficacy of Zn<sup>2+</sup>contaminated soil under modified mass ratio, Zn<sup>2+</sup> concentration, carbonation time, and curing agent incorporation was investigated. The findings indicate that the optimal adsorption efficiency was attained following the co-pyrolytic modification of activated MgO with corn stover biochar at 700°C. The optimal modified mass ratios for curing were found to be 1:1, 1:2, and 2:1 at Zn<sup>2+</sup> concentrations of 0.1 %, 0.5 %, and 1 %, respectively. At a lower Zn<sup>2+</sup> concentration, peak carbonization intensity is achieved at 0.5 hours, while at a 1 % Zn<sup>2+</sup> concentration, peak intensity is reached at 1 hour. The deformation modulus of the cured soil increases as the curing agent dosage increases and the soil aggregates become denser. SEM results show that: The carbonization and curing reaction products are mainly nesquehonite and Mg (OH)<sub>2</sub>. The internal structural damage of the cured soil was aggravated by the increase in Zn<sup>2+</sup>concentration, and the generation of nesquehonite and Mg (OH)<sub>2</sub> was inhibited; The carbonation time was extended to 1 h and the soil structure stability was enhanced.</p></div>\",\"PeriodicalId\":288,\"journal\":{\"name\":\"Construction and Building Materials\",\"volume\":\"449 \",\"pages\":\"Article 138341\"},\"PeriodicalIF\":7.4000,\"publicationDate\":\"2024-09-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Construction and Building Materials\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0950061824034834\",\"RegionNum\":1,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CONSTRUCTION & BUILDING TECHNOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Construction and Building Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0950061824034834","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}
Strength characteristics and microscopic mechanism of activated MgO-modified biochar carbonization curing Zn2+ polluted soil
Conventional curing agents are associated with environmental impacts when treating Zn2+contaminated soils. To overcome this limitation. In this study, we study a new type of MgO-CSB curing agent. Namely, corn stover biochar is modified with activated MgO. Modification of corn stover biochar using activated MgO, and carbonation curing was adopted to solidify/stabilize the Zn2+contaminated soil. The curing efficacy of Zn2+contaminated soil under modified mass ratio, Zn2+ concentration, carbonation time, and curing agent incorporation was investigated. The findings indicate that the optimal adsorption efficiency was attained following the co-pyrolytic modification of activated MgO with corn stover biochar at 700°C. The optimal modified mass ratios for curing were found to be 1:1, 1:2, and 2:1 at Zn2+ concentrations of 0.1 %, 0.5 %, and 1 %, respectively. At a lower Zn2+ concentration, peak carbonization intensity is achieved at 0.5 hours, while at a 1 % Zn2+ concentration, peak intensity is reached at 1 hour. The deformation modulus of the cured soil increases as the curing agent dosage increases and the soil aggregates become denser. SEM results show that: The carbonization and curing reaction products are mainly nesquehonite and Mg (OH)2. The internal structural damage of the cured soil was aggravated by the increase in Zn2+concentration, and the generation of nesquehonite and Mg (OH)2 was inhibited; The carbonation time was extended to 1 h and the soil structure stability was enhanced.
期刊介绍:
Construction and Building Materials offers an international platform for sharing innovative and original research and development in the realm of construction and building materials, along with their practical applications in new projects and repair practices. The journal publishes a diverse array of pioneering research and application papers, detailing laboratory investigations and, to a limited extent, numerical analyses or reports on full-scale projects. Multi-part papers are discouraged.
Additionally, Construction and Building Materials features comprehensive case studies and insightful review articles that contribute to new insights in the field. Our focus is on papers related to construction materials, excluding those on structural engineering, geotechnics, and unbound highway layers. Covered materials and technologies encompass cement, concrete reinforcement, bricks and mortars, additives, corrosion technology, ceramics, timber, steel, polymers, glass fibers, recycled materials, bamboo, rammed earth, non-conventional building materials, bituminous materials, and applications in railway materials.