The Major Environmental Behavior Of Common Herbicides In Soils Of Maizefield And Soil Remediation

In this paper, the method of High Performance Liquid Chromatography (HPLC) was used to detect the residues of Atrazine, Nicosulfuron and mesotrione.The adsorption and leaching behavior of 3 herbicides in four kinds of soil was studied.the conditions such as illumination, temperature, water content, pH, microbial quantity were simulatied indoor to find the most important Influence factor.3 photosensitizers were selected as the catalyst for accelerating the degradation of mesotrione.Trichoderma and biochar were used to repair the soil. The results are as follows:The adsorption process of 3 herbicides in four kinds of soil can reach the balance in a few hours. Adsorption in soil can be described by Feundlich adsorption model.The correlation between adsorption coefficient K and soil pH, organic matter content (%), cation exchange capacity (CEC), physical clay content (< 0.01 mm) were tested. Thefactor, organic matter content, was dominating factor for adsorptionof Atrazine or Nicosulfuron in soils; the adsorption of mesotrione dominating factors as pH value. pH value hasmost effected on the adsorption of mesotrione.The 3 kinds of herbicides were easy to migrate to the soil 30 cm below. Therefore, in order to prevent the decline of drug effect, The 3 kinds of herbicides should be Used in sunny weather.In addition,soilwhich has low organic matter content will accelerate atrazine or Nicosulfuron leaching.soil which has high pH value accelerate the migration of mesotrione. And It is dangerous to use these 3 kinds of herbicides in water sources.The degradation of mesotrione insoil were closely related to environmental conditions. Light and temperature had little effect on mesotrione degradation, and soil pH, water content, microbial content change has obvious effect on the degradation. One of the reasons that the degradation rate of mesotrione in soils increased was the high water content which can make the increase microbial activity. The feasibility of photocatalytic degradation of mesotrione using TiO2, Fe2O3 and humic acidas photocatalysts was studied. The experiment results show thatThe degradation rate of mesotrione was significantly accelerated by adding the catalyst in the soil sample.TiO2 was the best catalyst.Remediation of soil with biochar or Trichoderma strains was studied by the pot experiment.The results suggest that biocharor and Trichoderma named Ttrmll and Ttrm12 can remedy Atrazine contaminated soils.5% biochar has the better effect on remediation of Atrazine contaminated soils.Both of biochar and Trichoderma named Ttrm11 and Ttrm12 can remedy Nicosulfuron contaminated soil.5% biochar has the better effect on remediation of Nicosulfuron contaminated soils.