Study On The Treatment Of Organophosphorus Pesticide Wastewater By UV/Ferrate

Organophosphorus pesticide wastewater is an important part of phosphorus pollutionand environmental hazards, and Organic phosphorus pesticide is worldwidely used. Onceflow into the environment, it leads to eutrophication which destroys the ecological balanceon the one hand, and Pesticides Residue in crops accumulates in the body on the otherhand, making human tissues damage. Organic phosphorus pesticide molecules cover awide range of different characteristics, and an approach has not yet been found that can beuniversally applicable and effective. Biological treatment is of used through developingspecial bacteria, but Chemical methods are used more widely, including Fenton, TiO2photo-catalytic method and Ozone Oxidation, et al. Since ferrate is a new found efficientand environment-friendly oxidant, it has high values in application and research whetherused alone or in combination with other technologies, resulting from the much morestronger oxidizability of Fe(VI) and derived Fe(V), Fe(IV) than Fenton, ozone, KMnO4and ClO4-. This article chooses two representative organic phosphorus pesticides,profenofos and glyphosate, to study the treatment effects by UV/FeO42-system, and theirmechanisms.Ferrate was prepared by Direct Electrochemical Method in, and the optimum parametersof were found, viz. the optimal concentration of NaOH is14~16M, and through accessing thecurrent of0.15A/cm~2~0.2A/cm~2for2~4h under25~30℃, approximately35mmol/L of ferratecould be stably obtained. The oxidant gained a significant removal rate on the substratecombining with the co-catalyst of UV, which promoted deriving Fe(V) and Fe(IV)from Fe(VI),resulting its oxidation greatly enhanced at the optimum pH9.0.62.36%of profenofos wasremoved when Cprofenofos=10.0mg/L, and CFe(VI)：=250μmol/L, along with82.05%orthophosphate were claimed by dosing300μmol/L into the5.0mg/L of glyphosate(aq). TheCODCrin glyphosate showed similar removal trends with the substrate, but there’s a limit. Acomparative analysis of the effect of the two different pesticides was given in this study, too.This study obtained the optimum parameters, such as electrolyte concentration,current density, temperature and reacting time, of direct electrochemical preparation offerrate, and the effects of dosage, pH, substrate concentration, UV and dosing method onFe(VI) oxidation of pesticides.