| Now the environmental and food safety were concerned by all people, the pollution status of soil planted bamboo and its shoots ware investigated in Zhejiang province, and then the scientific evaluation were provided. Based the pesticide residue status, further research including bioremediation of organ-pesticides pollution, the role of environmental factor and isolation of degradation microorganism of organophosphorus pesticides were carried out. The main results were listed below:1 The status of pesticide residue in soil and shootsSeventeen organ-pesticides were detected in soil of bamboo forest, including eleven organochlorine pesticides and its isomers, four organophosphorus pesticides and two pyrethroids. The detection rate of HCH was up to 100%, which was higher than that of DDT. The detection of parathion–methyl was also up to 96.30%, and the detection rate of pyrethroid is low. The residual concentration of all was lower than 150μg·kg-1 excerpt esfenvalerate with the concentration of 1227.14μg·kg-1. The concentration of HCH and DDT was lower greatly than 50μg·kg-1, and that of organophosphorus pesticides was lower than 40μg·kg-1. So all that showed although the organ-pesticide residue in soil was ubiquitous, its concentration is low excerpt one pryethroid.Nine organochlorine pesticides were detected in shoots, and none of organophosphorus pesticides, pyrethroids and others were detected. The detection rate of both HCH and DDT was up to 100%, and the stability of DDT was higher than that of HCH in shoos. The detection rate of pentachlornitrobenzene was 75%. The average of all organ-pesticide residue is lower than 50μg·kg-1. The Nemerow index and cluster showed that tested shoot samples can be divided into two types: safety shoot, accounting for 82.14%; and fundamental safety shoot, accounting for 17.86%. All indicated that organochlorine pesticides residue of bamboo shoots form Zhejiang province was universal, but not severe.In addition, management level, management types and topographty influenced organ-pesticide residue in soil and shoots to some extent. The residual concentration of pesticides was higher in soil and shoots under intensive management bamboo forests, shoot-used bamboo forest, and bamboo forest converted from cropland than in those under extensive management bamboo forest, phyllostachys pubescens shoot-timber-used forests, and bamboo forest established on mountains, respectively.2 Bioremediation of organ-pesticides residue in soil of bamboo forest The result showed that pesticide concentration in soil can be decreased after bioremediation markedly. The degradation rate of parathion–methyl, carbofuran and HCH was higher than 60%, which was 83.08%, 82.66% and 62.21% respectively after 15-days bioremediation. The pesticide degradation rate of bioremediation was significantly higher than that of control. Stand density of bamboo plantation influenced bioremediation of parathion–methyl remarkably. Significantly difference at bioremediation was found among different density. The optimal density of bamboo plantation is 15000-18000 culms·hm-2.Three organophosphorus pesticides including dimethoate, parathion–methyl, acephate were detected in soil of degenerative Phyllostachys praecox stand, and their residual concentration was positive correlation with degeneration. Bioremediation used by degradation microorganism can eliminate organophosphorus pesticides markedly. The degradation rate was higher than 69%, and up to 100% after 15-days bioremediation. Degeneration can influence bioremediation greatly. With the graveness of degeneration, the degradation rate decreased remarkably.3 The influence of environmental factor on bioremediationEnvironmental factors such as soil temperature, light, soil pH and water content of soil, influenced bioremediation of organophosphorus pesticides evidently. Although during the bioremediation, the degradation rate and content increased gradually, the degradation velocity decreased gradually. The result showed that soil temperature, soil pH and water content of soil were the key factors influencing on bioremediation of organophosphorus pesticides. The optimum factor combination of bioremediation was soil temperature 25℃, light 60%, soil pH 6.03 and water content of soil 15%.4 The influence of fertilization on bioremediation.The influence of fertilization on bioremediation was tested by quadratic orthogonal and regression method. The regression equation was established, and all reached significant level. Based on regression equation, the optimum fertilization combination was N-0.112g·kg-1, 0.113g·kg-1, 0.122g·kg-1; P2O5-0.083g·kg-1, 0.096g·kg-1, 0.093g·kg-1; K2O-0.077g·kg-1, 0.078g·kg-1, 0.088g·kg-1. At this condition, the degradation rate was up to 62.09%,84.79%and 96.13% at 5, 10 ,15 day after bioremediation respectively.5 Isolation for microorganism degradation of organophosphorus pesticidesTwo degraded microorganism were isolated from soil fetching from drainage outlet of Longyou insecticide factory and named OPDM-1,OPDM-2. They all were strains of Pseudomonas sp. Under laboratorial, OPDM-2 can degrade organophosphorus pesticides markedly.
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