摘要
随着我国工业和城镇的快速发展,化石能源的大量使用使得环境中多环芳烃(PAHs)残留量不断增加,给环境和人体健康带来严重危害。以2-4环PAHs为研究对象,探讨了热脱附温度、时间以及PAHs自身结构对热脱附效果的影响,简要分析了热脱附处理对土壤性质的影响,评估了管式炉热脱附的能耗。结果表明:低环PAHs的脱附率随着脱附温度的升高、脱附时间的延长呈升高的趋势;在脱附温度为300℃、脱附30 min条件下,2环PAHs(2R-PAHs)被完全去除,3环PAHs(3R-PAHs)和4环PAHs(4R-PAHs)的去除率分别为93.22%和83.85%。PAHs各组分满足修复目标DB11/T 811—2011《北京市场地土壤环境风险评价筛选值》标准的优选条件,具体如下:萘(Nap)在脱附温度为100℃、脱附10 min时修复达标;菲(Phe)和蒽(Ant)修复达标条件分别为250℃、30 min和150℃、60 min;荧蒽(Fla)和芘(Pyr)土壤残留量基本均高于标准筛选值,需进一步调整热脱附工况参数,或辅助添加改性剂协同修复以降低成本。热脱附后土壤粗颗粒比例减小,与扫描电镜中大颗粒破碎为小颗粒现象相符。该结果可为热脱附技术在PAHs污染土壤修复的应用提供理论参考。
With the rapid development of China’s industries and urbanization, the massive use of fossil energy has led to an increasing amount of PAHs residues in the environment, which poses serious hazards to the environment and human health. The effects of thermal desorption temperature, time and the structure of PAHs themselves on the thermal desorption were investigated with 2-4 ring PAHs. Additionally, the effect of thermal desorption on soil properties were briefly analyzed, and the energy consumption of thermal desorption in a tube furnace was also evaluated. The results showed that the desorption removal efficiency of low ring PAHs showed an increasing trend with the increase of desorption temperature and desorption time. Under the conditions of 300 ℃ and 30 min of desorption, 2 ring-PAHs was completely removed, and the removal efficiency of 3 ring-PAHs and 4 ring-PAHs was 93.22% and 83.85%, respectively. The preferred conditions for each PAHs component to meet the objective values of the remediation standard(DB11/T 811—2011) were as follows: Nap was remediated at a desorption temperature of 100 ℃ for 10 min;Phe and Ant were remediated at 250 ℃ for 30 min and 150 ℃ for 60 min, respectively;the residues of Fla and Pyr were basically higher than the standard screening values, which required further adjustment of the thermal desorption working parameters or the addition of modifiers for synergistic remediation to reduce the cost. Moreover, the proportion of coarse soil particles decreased after thermal desorption, which was consistent with the fragmentation of large particles into small particles in SEM. The results can provide theoretical references for application of thermal desorption technology in remediation of PAHs contaminated soil.
作者
陈春红
徐成华
于天
刘刚
张亚平
洪雅敏
CHEN Chunhong;XU Chenghua;YU Tian;LIU Gang;ZHANG Yaping;HONG Yarnin(Key Laboratory of Thermal Conversion and Control of Ministry of Education,School of Energy and Environment,Southeat University,Nanjing 210096,China;Jiangsu Nanjing Geo-engineering Survey Institute,Nanjing 210041,China)
出处
《环境工程》
CAS
CSCD
北大核心
2022年第1期78-85,共8页
Environmental Engineering
基金
国家自然科学基金面上项目(42077126)
江苏省环境工程重点实验室科研开放基金(KF2018002)。
关键词
异位热脱附
低环PAHs
污染土壤
土壤修复
ex-situ thermal desorption
low-rings PAHs
contaminated soil
soil remediation
