改性塿土对土壤有机污染物苯酚运移的阻滞模拟  

Soil organic polluted matter phenol migration characteristics in modified loessial soil

作　　者：狄鑫[1] 孟昭福[2,3] 杨淑英[1] 崔晓波[1] 向伟[2] 任文理[2] 杨亚莉[1] 李文斌[2] 吴琼[2] 

机构地区：[1]西北农林科技大学理学院,杨凌712100 [2]西北农林科技大学资源环境学院,杨凌712100 [3]农业部西北植物营养与农业环境重点实验室,杨凌712100

出　　处：《农业工程学报》2015年第11期249-255,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：陕西省社会发展攻关项目(2013K13-01-05);陕西省农业科技攻关项目(2012K02-15)资助

摘　　要：为了防止和控制污染物在土壤中纵向迁移，保护地下水免受污染。该研究通过饱水土柱运移试验，用非反应性离子Cl-探求土柱参数弥散系数，并运用平均孔隙水流速和弥散系数求算反应性溶质苯酚的运移参数阻滞系数，探究十六烷基三甲基溴化铵（cetyltrimethylammonium bromide，CTMAB）改性土和原土对苯酚运移的阻滞效应，以及改性比例、pH值、离子强度等因素对苯酚在土柱中运移的影响。结果表明：以 CTMAB 改性黏化层塿土，显著增强了土壤对苯酚运移的阻滞能力。改性土对苯酚运移的阻滞能力随着改性比例的增加而增强，苯酚在100%改性土中运移的阻滞系数值是在原土中的26.06倍；pH值在6.0～8.0变化时，对苯酚在改性土中运移的阻滞作用影响不大；当离子强度在0.001～0.1 mol/L范围内，随着离子强度的增加，原土和改性土对苯酚运移的阻滞能力均减弱，原土对苯酚的阻滞系数由0.56降至0.37，100%改性土由17.57降至8.71。以100%改性比例制备的改性土在中性环境，离子强度为0.001 mol/L环境中对苯酚的阻滞效果最好。In order to prevent and control longitudinal migration of pollutants in soil and protect the groundwater from pollution, saturated soil column transport experiments were conducted,and the software CXTFIT2.1 was used for fitting the parameters from the experiments. This study aimed to explore retarding effect of the cetyltrimethylammonium bromide （CTMAB） modified soil and raw soil on migration of phenol, and to investigate the effect of modification ratio, pH, ionic strength on phenol migration in soil column. The results showed that with the software CXTFIT2.1, the deterministic equilibrium CDE （EM） model can be used to simulate breakthrough curves of Cl-, and the deterministic non-equilibrium CDE （NEM） model can be used to simulate breakthrough curves of phenol well. Non-reactive Cl- was used to determine the soil column parameter dispersion coefficient when average pore water velocityvwas fixed. Then the average velocity of pore water and dispersion coefficient were used to calculate the transport parameter retardation factor of the reactive solute phenol. Clay layer of Lou soil modified by CTMAB significantly enhanced the retardant ability of soil for phenol migration. The greater the modification ratio was, the later the flow time of phenol was, and the greater the retardation coefficient was. With the modification ratio increasing from 0 to 100%, the flow time of phenol was delayed by 3.90 to 82.65 pv, and the retardation coefficient increased from 0.48 to 12.51. So the increase of modified soil proportion can block phenol transportation, and increase the retention quantity of phenol. In other words, the retention ratio more than 25% modification ratio soil samples reached about 50% for phenol, while the retention ratios of CK and 10% modification ratio soil samples for phenol were only about 20%. The pH values ranging from 6.0 to 8.0 had almost no effects on blocking phenol migration in the modified soils. The flow time of phenol in raw soil remained at around 0.45 pv, and the retardation coeffi

关 键 词：土壤 污染 有机物 苯酚 十六烷基三甲基溴化铵 改性土 运移 pH值 离子强度 

分 类 号：X53[环境科学与工程—环境工程]