活化过硫酸钠去除长期污染土壤中的TPH  

Application of persulfate to remediatiate long-term TPH contaminated soils

作　　者：吴昊[1] 孙丽娜[1] 李玉双[1] 王辉[1] 王晓旭[1] 

机构地区：[1]沈阳大学环境学院区域污染环境生态修复教育部重点实验室,沈阳110044

出　　处：《环境工程学报》2016年第9期5231-5237,共7页Chinese Journal of Environmental Engineering

基　　金：国家重点基础研究发展计划项目(2014CB441106);沈阳市科技计划项目(F14-133-9-00);沈阳市科学事业费竞争性选择项目(城市生态风险管理及其修复技术研究);科技部中德科技合作项目(S2012ZR01912)

摘　　要：探讨了利用过硫酸钠氧化修复实际污染场地长期高浓度石油类(TPH)污染土壤的可行性。研究了过硫酸钠的活化方式、添加量、添加方式、土壤初始p H等因素对TPH降解效率的影响,并采用探针化合物研究了活化过硫酸钠对TPH的氧化去除机制。结果表明:Fe^(2+)活化方法对TPH去除效果最好,反应24 h最高去除率达40.8%;碱活化效果次之,去除率可达35.2%;过氧化氢活化效果一般,去除率为21%左右;热活化效果较差,去除率仅为15.6%。Fe^(2+)活化过硫酸钠去除土壤中TPH的反应在5 min内基本完成,最佳过硫酸钠用量为2.5 mmol·g-1土,过硫酸钠/硫酸亚铁/柠檬酸投加量之比为4∶1∶1,一次添加氧化剂的方式较多次添加效果好。实验场地土壤初始p H对TPH降解效果影响不大,自由基探针实验证实反应中硫酸根自由基、羟基自由基、还原性物质的存在。对于本场地污染土壤的修复,利用Fe^(2+)活化过硫酸钠修复是较为有效、快速的方法。Laboratory batch-scale experiments were conducted to evaluate the feasibility of remediating long-term petroleum hydrocarbon-contaminated soil by using persulfate oxidation. The factors considered included different activation, different persulfate concentrations, additional methods of persulfate activation, and the initial pH of the soils. Probe chemicals were used to study the persulfate oxidation mechanism. The results showed that the best activation method was the use of Fe2~ , which possessed an efficiency of 40.8% for TPH degradation o- ver 24 h. With regard to the alkaline and hydrogen peroxide activation treatments, the TPH degradation efficien- cies were 35.2% and 21% , respectively. The efficiency of thermal activation was low at a value of only 15.6%. The reaction was substantially complete within 5 min, and the optimum dosage of sodium persulfate was 2.5 mmol · g-1 soil, with the sodium persulfate/ferrous sulfate/citrate dosage ratio being 4： 1： 1. In addition, the re- sults revealed that the one-time addition of persulfate was superior to multiple additions. The addition of probe compounds showed that the formation of sulfate radicals, hydroxyl radicals, and reductants. The results sugges- ted that activated persulfate could be a feasible technology to remediate long-term TPH-contaminated soils.

关 键 词：化学氧化修复 石油类污染物 过硫酸钠 自由基 

分 类 号：X53[环境科学与工程—环境工程]