过硫酸盐修复有机污染土的效果及强度特性研究  

The effectiveness and strength characteristics of persulfate-remediated organic-contaminated soil

作　　者：王菲 叶子俊 苗文权 徐建 WANG Fei;YE Zi-jun;MIAO Wen-quan;XU Jian(School of Transportation,Southeast University,Nanjing,Jiangsu 210096,China;State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control,Nanjing Institute of Environmental Sciences,Ministry of Ecology and Environment of China,Nanjing,Jiangsu 210042,China)

机构地区：[1]东南大学交通学院,江苏南京210096 [2]生态环境部南京环境科学研究所国家环境保护土壤环境管理与污染控制重点实验室,江苏南京210042

出　　处：《岩土力学》2024年第12期3635-3644,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金面上项目(No.51978157);国家重点研发计划(No.2018YFC1803100)。

摘　　要：对二价铁离子活化过硫酸盐修复后的1,2-二氯苯污染土进行降解试验、微观测试、颗粒分析试验、液塑限试验、无侧限抗压强度试验和不排水剪切试验,揭示了过硫酸盐修复有机污染土的效果及土的强度特性变化规律。结果表明,15.0%的Fe^(2+)活化过硫酸盐掺量对1,2-二氯苯去除率高达92.59%,反应后有硫酸钠、硫酸钙以及氢氧化铁等物质生成;少量的硫酸钠、硫酸钙填充土颗粒间的孔隙,使土更为密实;但大量的硫酸钠晶体的膨胀效应会削弱土颗粒间联结,使土变得松散;修复后的土中黏粒含量增加,粉粒和砂粒含量减少;液限和塑性指数随掺量增加而逐渐增大,塑限则逐渐减小,塑性能力稍有提升;无侧限抗压强度和剪切破坏时的最大剪应力随掺量的增加先增大后减小,当过硫酸盐掺量为10.0%时,修复后土的无侧限抗压强度可增大到310.75 kPa,增大幅度为20.34%,剪切破坏时的最大偏应力可达到142.73 kPa。To investigate the efficacy and strength properties of Fe^(2+)-activated persulfate remediation for 1,2-dichlorobenzene-contaminated soil with varying persulfate concentrations,we conducted degradation,microscopic,particle size,liquid-plastic limit,unconfined compressive strength(UCS),and undrained shear tests.The results indicate that adding 15.0%Fe^(2+)-activated persulfate achieves a 92.59%removal rate of 1,2-dichlorobenzene.Furthermore,the reaction produces sodium sulfate,calcium sulfate,and ferric hydroxide.Small amounts of sodium sulfate and calcium sulfate fill the pores between soil particles,leading to a denser soil structure.However,the expansive effect of excessive sodium sulfate crystals weakens the inter-particle cohesion,leading to soil loosening.After remediation,the clay content increases,while the silt and sand content decreases.The liquid limit,the plastic capacity and the plastic index increase,while the plastic limit decreases with the increase of the persulfate dosage.The UCS and the maximum shear stress decrease with the increase of the persulfate dosage.The UCS of the soil treated by 10.0%persulfate is 310.75 kPa,20.34%higher than the strength of untreated soil.The maximum deviator stress at shear failure is 142.73 kPa.

关 键 词：化学氧化 活化过硫酸钠 有机污染土 强度特性 

分 类 号：TU411.3[建筑科学—岩土工程]