有机-无机复合固化剂合成及重金属污染底泥固化研究  

SYNTHESIS OF ORGANIC-INORGANIC COMPOSITE CURING AGENT AND ITS SOLIDIFICATION EFFECT ON HEAVY METAL CONTAMINATED DREDGED SILT

作　　者：陈运涛[1,2,3,4] 肖瑶 王健男 高忠帅 崔美 黄仁亮 CHEN Yuntao;XIAO Yao;WANG Jiannan;GAO Zhongshuai;CUI Mei;HUANG Renliang(CCCC Tianjin Port Engineering Institute Co.,Ltd.,Tianjin 300222,China;Key Laboratory of Port Geotechnical Engineering of the Ministry of Communication,Tianjin 300222,China;Key Laboratory of Port Geotechnical Engineering of Tianjin,Tianjin 300222,China;First Harbor Engineering Co.,Ltd.,CCCC,Tianjin 300222,China;School of Marine Science and Technology,Tianjin University,Tianjin 300072,China)

机构地区：[1]中交天津港湾工程研究院有限公司,天津300222 [2]港口岩土工程技术交通运输行业重点实验室,天津300222 [3]天津市港口岩土工程技术重点实验室,天津300222 [4]中交第一航务工程局有限公司,天津300222 [5]天津大学海洋科学与技术学院,天津300072

出　　处：《环境工程》2024年第3期82-91,共10页Environmental Engineering

基　　金：天津市重点研发计划(18YFHBZC00010)。

摘　　要：疏浚重金属污染底泥由于具有含水率高、强度低等特性,无法直接作为工程材料应用,并且会对环境造成污染。设计合成了一种丙烯酸-苯乙烯磺酸共聚物(AA-SSS),并与水泥和纳米水化硅酸钙(早强剂)混合,开发了一种有机-无机复合固化剂。探究了有机-无机复合固化剂对底泥固化抗压强度和重金属离子稳定化的影响,并分析了其机理。结果表明:有机-无机复合固化剂对底泥固化强度增强效果显著,在10%水泥、1%AA-SSS、2%早强剂添加量下,底泥固化1 d的抗压强度为0.85 MPa,相比未加固化剂,提高了467%。在该条件下,底泥中的Pb^(2+)、Ni^(2+)、Cd^(2+)、Cr^(3+)的浸出浓度分别从7.05,8.32,4.40,7.12 mg/L降至2.68,2.61,0.68,2.05 mg/L,经固化稳定化后底泥酸浸出液中重金属浓度均低于危险废物鉴别标准值。水泥水化产物加强了淤泥颗粒之间的胶结,并包裹固定金属离子,同时AA-SSS和纳米水化硅酸钙可以分散和促进水泥水化,并通过静电作用和吸附作用固定金属离子。研究表明有机-无机复合固化剂在提高底泥抗压强度和重金属离子稳定化具有良好的应用前景。Dredged silt has the characteristics of high moisture content and low strength,resulting in the inability to be applied directly as an engineering material.It can also pose risk to the environment.In this study,an organic-inorganic composite curing agent was developed,consisting of a synthetic copolymer of acrylic acid and styrenesulphonic acid(AA-SSS),cement,and nano-hydrated calcium silicate(early strength agent).The effect of organic-inorganic composite curing agents on the compressive strength of substrate curing and stabilization of heavy metal ions was investigated and the mechanism was analyzed.The results showed that the organic-inorganic composite curing agent was effective in enhancing the strength of the cured substrate.With the addition of 10%cement,1%AA-SSS,and 2%early strength agent,the compressive strength of the substrate cured for 1 day was 0.85 MPa,increased by 467%compared to that without the addition of curing agent.Under these conditions,the leaching concentrations of Pb^(2+),Ni^(2+),Cd^(2+),and Cr^(3+)in the sediment decreased from 7.05,8.32,4.40 and 7.12 mg/L to 2.68,2.61,0.68 and 2.05 mg/L,respectively.The concentrations of heavy metals in the acid leachate of the solidified and stabilized substrate were all below the hazardous waste identification standard values.The cement hydration products enhance the cementation between the silt particles and encapsulate the immobilized metal ions,while AA-SSS and nano-hydrated calcium silicate disperse and promote cement hydration and immobilize the metal ions by electrostatic action and adsorption.The results show that the organic-inorganic composite curing agent has great potential to improve the compressive strength of silt and the stabilization of heavy metal ions.

关 键 词：重金属 污染底泥 固化剂 无侧限抗压强度 稳定化 

分 类 号：X52[环境科学与工程—环境工程]