某有机废弃场地土壤化学分析与生态毒性诊断研究

Chemical Analysis and Eco-toxicity Diagnosis on Organics Contaminated Soil from an Abandoned Site

本研究采集了某有机废弃场地不同区域的土壤样品，分析了样品中重金属与半挥发性有机物浓度，并对场地土壤进行了生态毒性试验。结果表明，场地土壤无重金属污染，检出的半挥发性有机物有5类33种，其中有多种具有强致癌性的多环芳烃类污染物。各样品中，J-2点污染最为严重，J-3点、J-5点次之，其他点各有一种目标污染物检出。场地土壤对植物和蚯蚓均显示出较强的毒性效应，对玉米和小白菜种子发芽根伸长抑制率分别达到了4．71％～70％和57．03％～100％，小白菜对场地污染较为敏感。J-2点、J-3点、J-5点的蚯蚓7d死亡率达到了100％；J-1点、J-4点和对照在28d试验期内无死亡，J-1点、J-4点28d体重增长抑制率为45．58％和50．54％，明显高于对照的13．93％。研究表明，对于目标污染物不明确的污染场地，将化学分析与生态毒性指标相结合是诊断污染场地环境风险的有效手段。

Recently, soil environmental problem of abandoned industrial sites is gradually rising in certain area of China. Research on site/ soil investigation and eco-toxicity test will contribute to identification of risks related to site/soil contamination. In this study, soil samples were colleeted from an organics contaminated site. Soil samples were analyzed for concentrations of heavy metals and semi-volatile compounds. Eco-toxicity test using eorn（Zea mays ）, cabbage（Brassica chinensis ）, and earthworm （Eiseniafetida）, were performed. The results showed that various types of contaminants, including pesticides and some carcinogenic polycyclic aromatic hydrocarbons, were detected in the soil samples. Heavy metals concentrations in the soil were well below the related environmental quality standards. Soil samples from the J-2 spot were most seriously contaminated, and samples from the J-3 spot and J-5 spots were less contaminated. Only one contaminant was detected in soil samples from other spots. The soil used in the eeo-toxicity test showed significant inhibition effects on plant and earthworm growth. The inhibition rates of root elongation of corn and cabbage were 4.71%-70% and 57.03%-100%, respectively. Cabbage seems to be more sensitive to the contamination. The mortality test showed that death rates of earthworm in soil from the J-2, J-3 and J-5 spots all reached 100% within 7 days, while for the contrast spots, i. e. the J-1 spot and J-4 spot, all the earthworm were alive during a test period of 28 days. For soil from the J-1 and J-4 spots, the inhibition rate for body weight of the earthworms after 28 days were 45.58% and 50.54%, respectively, which are obviously higher than 13.93%, the inhabitation rate of the contrast spot. A general conclusion is that chemical analysis in combination with eco-toxicity test may be an effective approach to identify potential hazard and risks related to contaminated soil/site, and furthermore, provide useful information for decision-making of environmental management.