Development And Environmental Safety Analysis Of Environment-friendly Pesticide Butralin Water Dispersible Granule

Pesticide is an important means for human to control agricultural disease and insect pests and weeds. Social development and the progress of science and technology promote the innovation of pesticide industry, as market competition intensifies and the human consciousness of environmental protection, people’s requirements for pesticide safety is becoming more and more rigorous. The environment is polluted seriously and Human beings are harmed by the organic solvents and high dust in traditional pesticide formulations such as Emulsifiable Concentrate(EC),Wettable Podwers(WP) and Powders. Therefore it is urgent to research and develop the new pesticide formulations which are safe, high effective and environmental friendly. In recent years, water dispersible granules(WDG) has become much more popular formulation. Its advantages are non-solvents, low in dust, convenient use and so on. Butralin is a herbicide,Currently, only a single EC formulations. Water dispersible granule(WDG) is a new pesticide formulation, which is safe and friendly for environment. Butralin WDG has been developed in this thesis. New dosage forms can quickly disintegrate, disperse to form a high suspension system in the water and remains good herbicidal effect When used in the field. It has many advantages and broader application prospects for sustainable secio-economic development.In this thesis,the mainly six sections of experimental are studied:(1) Butralin Wettable Powder(WP) new formulation development. According to requirements of WP formulation and physicochemical properties of butralin, Many experiments were investigated. Such as single-factor screening of carriers and additives, orthogonal design to the preferred dispersant system. The results showed that the best formulation of the butralin WP are: butralin original drug of 44.5%, bentonite of 44.5%, DBS-Na of 6%, sodium ligninsulfonate of 3%, CMC of 1%, PVA of 0.5% and sodium tripolyphosphate of 0.5%. In accordance with the national standard method for measuring, various performance indicators of butralin WP are in line with the national standard. Butralin content is 41% in wettable powder.(2) Herbicidal effect experiments of butralin WP. Comparative experiments were done and the weed removal effects of butralin WP are very good. Field recommended dose of 330g~380g/667m2. Butralin WP should be sprayed under good soil moisture conditions and mixed with soil immediately after pesticide application. Compared with 48% butralin EC, the treatment effects and wheat yield increase are all the same. This shows that the new formulation does not destroy butralin structure and affects its usage effect. It provides the basis for the study of butralin WDG, pesticide registration and agricultural production.(3) Research experiments of butralin WDG. According to butralin WP formulation, CMC and PVA as binders, butralin WDG is prepared by the processing technology of dry extrusion granulation and technological process is determined. Through the determination of the technical indicators, products are qualified to achieve the desired design goals.(4) Study on the formation mechanism and characteristics of butralin WDG. It is necessary that the structure, reaction mechanism between butralin and auxiliaries in WDG are studied. By modern physical and chemical techniques, the microstructure surface characterization and reaction mechanism between butralin and auxiliaries of WDG were characterized. such as scanning electronic microscopy(SEM), Transmission Electron Microscope(TEM), X-ray diffraction(XRD), Infrared Spectroscopy(IR) and Differential Scanning Calorimetry(DSC). XRD curve certified butralin crystal form was not changed. DSC and IR analysis suggested that the interaction of butralin and auxiliaries or auxiliaries each other are all physical action and intermolecular force, no chemical bond.(5) Environmental safety analysis of butralin WDG. Butralin WDG is environmentally safety by analyzing that effect of butralin WDG on soil microorganism population, soil respiration intensity and experiment of the toxicity of butralin WDG on earthworm. The impact of organic solvents(BTEX) used by butralin EC on the environment and the environment safety evaluation of the each agent used by butralin WDG, further explained the new formulation is environment security compared with the trdditional emulsion.(6) Economic benefit comparison between butralin WDG and butralin WP. Production of one ton WDG costs 26,477 yuan(26.5 yuan/kg) and production of one ton EC costs 40,000 yuan(40 yuan/kg). The new formulation can produce better social and economic benefits.