固定化白腐真菌对农药污染土壤的原位修复

发布时间：2018-03-10 18:00

  本文选题：克百威　切入点：毒死蜱　出处：《沈阳工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：玉米杆、麦秆、花生壳等为常见的农业废弃物,除少部分作为饲料外,大部分被直接焚烧,利用率低,对环境危害大。克百威和毒死蜱为两种常见的广谱杀虫剂,在农业生产上被广泛应用。但克百威和毒死蜱半衰期长,不易被降解,在土壤中的残留会给农作物和人类健康造成严重影响。因此,修复克百威和毒死蜱污染土壤刻不容缓。本文通过吸附法将白腐真菌固定化,并将其应用于克百威和毒死蜱污染土壤的原位修复,为农药污染土壤的修复工作提供一个新思路。本文通过以玉米杆、麦秆、花生壳等作为载体固定化三株白腐真菌C菌株(Phlebia.sp)、Y菌株(Lenzites betulinus)和W菌株(Iopex lacteus),以克百威和毒死蜱为目标污染物,以降解率作为考察指标,分别筛选出克百威和毒死蜱的优势降解菌株以及较优载体。结果表明,玉米杆和麦秆较适合作为载体来固定化白腐真菌,且以玉米杆为载体的菌株降解效果好于麦秆载体,C和W为克百威的优势降解菌株,C和Y为毒死蜱的优势降解菌株。白腐真菌培养最适温度为28℃,且偏酸性条件下白腐真菌在载体上长势较好。固定化后W菌株5d内对克百威的降解率最高为69.83%,C菌株6d内对毒死蜱的降解率最高为74.69%。固定化后的三株菌株进行环境因子影响的考察表明:污染物初始浓度变化很大时,固定化白腐真菌对两种农药的降解效果波动均不大,其降解能力受浓度影响较小。然而当pH、温度以及初始投加量变化时,固定化白腐真菌对农药的降解效果变化较大,白腐真菌受这三种环境因子影响较大。随后进行的正交实验验证了这一结论:在克百威降解正交实验中,反应温度是影响降解率的关键因素,pH值为重要因素,投加量及克百威的初始浓度为一般因素;在毒死蜱降解正交实验中,反应温度和pH值是影响毒死蜱降解率的关键因素,毒死蜱的初始浓度及投加量为一般因素。
[Abstract]:Corn stalks, wheat stalks, peanut shells and so on are common agricultural wastes. Except for a few as feed, most of them are incinerated directly, and their utilization ratio is low, which is a great harm to the environment. Carbovax and chlorpyrifos are two common broad-spectrum insecticides. It is widely used in agricultural production. However, the half-life of carbofuran and chlorpyrifos is long and not easily degraded, and residues in the soil have serious effects on crops and human health. The remediation of chlorpyrifos and chlorpyrifos contaminated soil is urgent. In this paper, the white rot fungi were immobilized by adsorption method, and used in situ remediation of Yu Ke and chlorpyrifos contaminated soil. This paper provides a new idea for the remediation of pesticide contaminated soil. Peanut shell was used as carrier to immobilize three white rot fungus strains Phlebia.sphalinus, Lenzites betulinusand W strain Iopex lacteus.Both chlorpyrifos and chlorpyrifos were used as the target pollutants, and the degradation rate was taken as the index. The dominant biodegradable strains and carriers of chlorpyrifos and chlorpyrifos were screened respectively. The results showed that corn stalks and wheat stalks were more suitable as carriers for immobilization of white rot fungi. The results showed that the strain with corn stalk as the carrier was better than those with wheat straw carrier C and W as the dominant degradation strains of chlorpyrifos. The optimum culture temperature of white rot fungi was 28 鈩，

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