Study On The Pretreatment Technology Of Pesticide Wastewater With High Concentration Of Organic Phosphorus By Catalytic Oxidation

In 2014, pesticide production in Chinaranks the first in the world and reached 3.744 million tons, and.80% of pesticide products belongs to organic phosphorus pesticide. These pesticide wastewaters discharged from the production process have some characteristicsof high organic phosphorus, high ammonia nitrogen, high COD, high salinity, high toxicity, and difficult to biochemical treatment, etc. At present, the researchers in the organic phosphorus pesticide wastewater pretreatment process, more concerned about the COD removal, and pay less attention to the organic phosphorus transformation, therefore, the actual production wastewater in a pesticide factory in Hubei as the research object. First of all, a variety of pretreatment techniques were compared, to explore the effect of pretreatment, then mainly discusses the under the condition of low pressure catalytic ozone, air oxidation and microwave heating conditions catalyzed by over oxidation of potassium sulfate of high concentration of organic phosphorus pesticide wastewater pre treatment effect. By means of FTIR, GC-MS and other means, the conversion and removal mechanism of organic phosphorus in wastewater was analyzed preliminarily. Main conclusions are as follows:(1) The traditional physical and chemical methods deal with actual pesticide wastewater, sush as adsorption, extraction, hydrolysis, flocculation precipitation, iron carbon micro electrolysis, electro flocculation, Fenton experimental, TP removal effect in about 25%; The removal rate of total phosphorus was only about 30% by pure ozone or Fenton oxidation. Chlorine oxidation for TP to removal effect is good, under the condition of 70 ? through 0.1 mol chlorine, after precipitation of phosphorus removal rate reached 48.8%;(2) Under the conditions of low pressure catalytic oxidation, iron manganese silicate catalyst catalytic effect is the best. In the ozone pressure 0.4MPa, heating temperature of 70 ?, reaction 90min, after precipitation of phosphorus removal rate was 33.1%, ammonia nitrogen removal rate of 41.3%.(3) In the microwave,120? catalyzed oxidation of potassium sulfate in, in acidic conditions (pH=3), after oxidation, magnesium salt precipitation after the removal rate of TP were at around 66.3%.(4) In heating of 120?, pH=3., adding 3g/50mL potassium persulfate and 5 g/L Fe Mn catalys 3 digestion time, the removal rates of total phosphorus, ammonia nitrogen, total organic carbon (TOC) were 92.6%,40.7%, and 60.9%.(5) After heating the catalytic oxidation of potassium sulfate wastewater by GC-MS, FTIR, direct heating potassium persulfate catalytic oxidation process can effectively degrade the organic phosphorus esters and organic sulfur compounds generated more alcohols and long chain hydrocarbons, enable the transformation of organic phosphate into inorganic phosphorus and by subsequent precipitation can be removed.(6) By infrared analysis, the main components of sediment is struvite. Its content is about 70%, a certain recovery value.