TCP污染土壤的植物修复及其毒性研究

目的]研究2,4,6-三氯酚(TCP)污染土壤的植物修复及其毒性,为氯酚植物修复技术的实际应用提供参考。方法]利用玻璃房盆栽试验,研究了苜蓿(Loliummultiflorum L.)对土壤中TCP污染的修复作用,苜蓿的生长情况和TCP对莴苣(Lactucasativa)种子发芽和根生长的毒性影响。结果]75 d的盆栽试验表明,土壤中TCP的可提取态浓度随着时间延长逐渐减少,苜蓿加快了土壤中可提取态TCP浓度的下降。对于种植苜蓿的污染土壤,在75 d培养中,1、10、100 mg/kg处理(低、中、高)的降解率分别是55.2%、80.2%、90.1%,无植物处理的降解率分别是20.1%、30.2%、49.2%。莴苣根的生长对TCP污染土壤的毒性敏感,可以作为污染土壤毒性的快速评价指标,但发芽率不能反映土壤的毒性变化规律,不宜作为评价TCP污染土壤的毒性指标。结论]种植苜蓿具有强化TCP污染土壤修复的作用,可通过促进苜蓿生长,增强土壤过氧化氢酶的活性,增强土壤微生物活性,提高苜蓿修复TCP污染土壤的能力。

TCP Contaminated Soil Phytoremediation and Its Toxicity Evaluation

Objective] The research aimed to study the 2,4,6-trichlorophenol(TCP)contaminated soil phytoremediation and its toxicity evaluation,and provide references for the Chlorophenols phytoremediation technology in the practical application.Method] Using plant to decontaminate organic pollutants-contaminated soil may be a good technology of low cost,effective and friendly to environment.Bioremediation of TCP contaminated soil by alfalfa(Medicago sativa L.) was studied in greenhouse.In addition,the research on seed germination and root growth of the toxicity test were made.Result] 75 days pot experiment showed that the concentration of TCP in soil grown alfalfa was significantly lower than that without plant grown(P<0.05).Under 1,10 and 100 mg/kg TCP treatments,TCP biodegradability amounted to 55.2%,80.2% and 90.1% respectively.The root growth of Lactuca sativa seeds was tenderness to TCP contaminated soil,and could be used as the evaluation index.But the seed germination rate of Lactuca sativa did not reflect the changes law of soil toxicity,and was not appropriate for evaluation of TCP contaminated soil toxicity of indicators.Conclusion] There results indicated that alfalfa could enhance the degradation rate of TCP in the TCP contaminated soil and increase alfalfa yield,enhance soil catalase and microbial activity,and could improve the ability of TCP contaminated soil bioremediation.