TCP在种植苜蓿土壤中的降解研究

Degradation of TCP in Soil Planted with Alfalfa(Medicago sativa L.)

[目的]研究TCP在苜蓿种植土壤中的降解作用,为氯酚类物质污染土壤生物修复技术的实际应用提供依据。[方法]利用玻璃房盆栽试验,研究苜蓿对土壤中2,4,6-三氯酚(TCP)污染的修复作用以及苜蓿的生长情况和TCP对土壤多酚氧化酶、脱氢酶和过氧化氢酶活性的影响。[结果]苜蓿经过75 d的生长后,在低、中、高3个浓度处理中,土壤中TCP含量均在15 d内迅速降低,随后降低速度逐渐变缓;在苜蓿生长30 d时,3个处理的苜蓿鲜重与对照间无显著差异(P<0.05),而在生长75 d时,各处理的苜蓿鲜重明显对照低(P<0.05),表明土壤中TCP对苜蓿的生长具有抑制作用;苜蓿能显著提高土壤中多酚氧化酶、脱氢酶和过氧化氢酶的活性,从而提高了土壤植物和微生物对污染物的降解能力。[结论]苜蓿能促进土壤酶活性的提高,促进土壤中有机物的降解,从而可以利用苜蓿进行TCP污染土壤的植物修复。

[Objective] The research aimed to study the degradation of 2,4,6-trichlorophenol（TCP） in soil planted with alfalfa（Medicago sativa L.）,as well as to provide references for the Chlorophenols phytoremediation technology in the practical application.[Method] By the use of pot culture experiment in greenhouse,the phytoremediation effect of alfalfa on TCP-contaminated soil,the growth conditions of alfalfa,as well as the effect of TCP on the activity of soil polyphenol oxidase,dehydrogenase and catalase were studied.[Result] After the alfalfa was grown for 75 d,the TCP content in soil of three different concentrations treatments（low,middle and high） decreased dramatically within 15 d,and then the decreasing rate was gradually slow;on the 30th d of cultivation,the fresh weight of treated alfalfa showed no significant difference with the control（P0.05）,indicating that TCP in soil had inhibition effect on the growth of alfalfa;alfalfa could significantly enhance the activities of polyphenol oxidase,dehydrogenase and catalase,thus raising the degradation capability of soil plants and microorganisms on pollutants in soil.[Conclusion] There results indicated that alfalfa could enhance the degradation rate of organics in the contaminated soil and enhance soil enzyme activity,so the alfalfa could be used for the bioremediation of TCP contaminated soil.