某有机污染场地土壤异味筛查和修复试验

Screening and Remediation Test of Soil Odor in an Organic Contaminated Site

针对某有机污染场地产生的土壤异味,利用吹扫捕集/气相色谱-质谱法测定了其中的挥发性有机物(VOCs),确定了其异味来源主要为2-氯甲苯。采用自然挥发、氧化钙辅助升温挥发、双氧水氧化处理和过硫酸钠/氧化钙氧化处理四种方法进行了异味治理修复试验。结果表明:常温自然挥发异味去除率可达到90%以上,氧化钙升温挥发、双氧水及过硫酸钠氧化均能在一定程度上提高去除率(4%~7%),但氧化反应难以将2-氯甲苯完全降解,且生成新的污染物邻氯苯甲醛。建议采用原位搅拌集气处理或原地异位常温挥发等工艺处理土壤中的异味,现场挖掘时采用覆盖或除臭技术防控异味逸散及二次污染。

The Volatile Organic Compounds(VOCs)in the soil odors produced from an organic contaminated site were determined by purge and trap/gas chromatography-mass spectrometry.The results showed that the main source of odor was 2-chlorotoluene.The odor treatment and remediation tests were carried out by four methods including natural volatilization,calcium oxide assisted heating and volatilization,hydrogen peroxide oxidation and sodium persulfate/calcium oxide oxidation.The results indicated that the odor removal rate by natural volatilization could reach more than 90% at room temperature,while the other three methods could improve the removal rate to a certain extent(4%~7%).But 2-chlorotoluene was difficult to be completely degraded by oxidation reaction and o-chlorobenzaldehyde was generated.Therefore,in-situ agitation and gas gathering or in-situ natural volatilization treatment was recommended to treat the odor,and on-site coverage or deodorization technology was used to prevent and control odor escape and secondary pollution during site excavation.