【作者】 刘军；

【导师】 王谦；

【作者基本信息】 江苏大学 ， 工程热物理， 2009， 博士

【摘要】 土壤中农药和重金属污染已成为一个严重的环境问题,而共存的重金属与农药的相互作用对环境的影响还知之甚少,对土壤环境的研究具有重要的意义。本文探讨了重金属铜对土壤中拟除虫菊酯农药吸附、迁移和降解的影响规律;从微观上探讨铜对拟除虫菊酯农药主要环境行为的影响机理,同时研究了铜与拟除虫菊酯农药复合污染对土壤酶活性和土壤微生物的影响规律。主要的创新成果如下:（1）利用振荡平衡法,研究了铜对两种典型土壤（东北黑土和江西红土）中氯氰菊酯和功夫菊酯吸附的影响规律,探讨了拟除虫菊酯农药在土壤中的吸附机理。结果表明功夫菊酯比氯氰菊酯具有更强的吸附能力。同样,黑土比红土对拟除虫菊酯农药也有更大的吸附能力。其原因为黑土比红土有更多的有机质和更大的比表面积,能够提供更多的吸附点位。随着土壤中铜的含量的增加,氯氰菊酯和功夫菊酯的吸附系数逐渐降低,这与铜跟拟除虫菊酯在土壤有机质表面的竞争吸附作用有关。（2）采用土壤薄层层析法,研究了功夫菊酯和氯氰菊酯在黑土和红土中的迁移性,并考察了不同浓度的铜对两种菊酯迁移性的影响规律。发现没有外源铜添加时,氯氰菊酯在红土和黑土中的R_f的平均值分别为0.055和0.046。与氯氰菊酯相比,功夫菊酯在两种土壤中有更弱的移动性。这两种菊酯均属于移动性很弱的农药品种。菊酯在两种土壤中的R_f也随着展开剂中铜的浓度的增大而增大,表明铜的存在有利于功夫菊酯和氯氰菊酯在土壤中的迁移。（3）研究了铜对氯氰菊酯和功夫菊酯光解、水解和土壤降解行为的影响以及降解产物及降解路径。随着pH的增加,菊酯水解加剧,铜的存在明显促进了菊酯的水解,这可能与Cu²⁺和菊酯分子形成的配合物有关。Cu（Ⅱ）的存在促进了菊酯的光解,但可以明显抑制这两种农药的土壤降解。（4）研究了铜和拟除虫菊酯对土壤酶活性、土壤呼吸作用和土壤微生物生物量碳的影响。当土壤中添加高浓度的铜和氯氰菊酯时,铜和氯氰菊酯的交互作用抑制了土壤过氧化氢酶的活性。铜和氯氰菊酯对土壤脲酶活性有一定程度的抑制作用。铜和拟除虫菊酯农药的复合污染刺激了土壤的呼吸强度,明显减少了土壤中微生物生物量碳的含量。更多还原

【Abstract】 Pesticides and heavy metals pollution in soft environment has become a serious problem in many countries including China.However,little attention has been given to determine combined effect of heavy metals and pesticides on the environment.Therefore,the aim of the present work was to examine the effect of Cu on the adsorption,transport,and degradation of pyrethroids in soils,and to investigate the eco-effect of combined pollution between Cu and pyrethroids on soil enzyme activity and soil microorganism.The main contents are as follows:（1） Batch equilibrium tests were conducted to examine the effect of Cu on the adsorption of lambda-cyhalothrin（λ-CHT） and cypermethrin （CPM） on two typical Chinese soils（black soil and red soil） with different soil characteristics.The probable adsorption mechanisms ofλ-CHT and CPM on soils were also revealed.The results showed thatλ-CHT showed a significantly stronger adsorption than CPM on both soils.Black soft had a stronger adsorbability than red soil to both pyrethroids,because of its larger organic matter and surface area.As the soil Cu concentrations increased from 19（or 18） mg·kg^-1 to 1600 mg·kg^-1,the adsorption coefficient ofλ-CHT and CPM decreased on both softs.This is mainly due to a competition between Cu and pyrethroids for occupying the adsorption sites on soils.（2） Thin layer chromatography（TLC） was used to investigate the effect of Cu on the transport of CPM andλ-CHT in soft.Without the addition of Cu,the Rf value of CPM in red soil and black soft was 0.055 and 0.046,respectively.λ-CHT had the lower Rf value than CPM.The transport of CPM andλ-CHT was weak and the gradation of their transferability was I grade.As Cu concentration of spread solution increasing from 1 to 100 mg/L,Cu also increased the Rf value of CPM andλ-CHT.The results showed that Cu could promote pyrethroids to transfer in soil.（3） Laboratory studies were conducted to investigate the influence of Cu on the hydrolysis,photo-degradation and soil degradation of CPM andλ-CHT.A number of degradation products had been characterized and identified by gas chromatography-mass spectroscopy（GC-MS）. Degradation pathways were also proposed.The hydrolysis of CPM andλ-CHT was rapid as the pH of the solution increasing from 5 to 9.The addition of Cu could promote the hydrolysis of CPM andλ-CHT.This is related with a chelation between Cu and pyrethroids.Appropriate application of Cu could promote the photodegradation of CPM andλ-CHT, but it could reduce the degradation of these pyrethroids pesticides in soil.（4） The effect of pyrethroids and Cu on soil enzyme activities,soil respiration and soil microbial biomass C was studied.The results showed that the catalase activity was declined after application of high concentrations of Cu and CPM.Combined pollution of Cu and pyrethroids had a positive influence on soil respiration.Soil microbial biomass C treated with Cu and pyrethroids was significantly lower than that of the control soil over the course of incubation.更多还原