Study On The Pretreatment Test And Engineering Commissioning Of Organic Silicon Production Wastewater

With the rapid development of silicone industry,the production capacity of silicone has become the first in the world.As the state attaches great importance to environmental protection,the waste water generated in the production process of organosilicon material cannot be ignored.In this paper,considering that the wastewater produced by a chemical enterprise during the production of organosilicon materials has many kinds of pollutants and high concentration,strong acid and alkali,high salt content and difficult biodegradation,the process of"air flotation+four-effect evaporation+Fenton oxidation+coagulation precipitation"is used to pretreat the high-concentration wastewater,and then the biological process of"UASB+A/O"is used to treat the wastewater.After a period of debugging and operation,the effluent meet the requirements of the park sewage treatment plant.In this paper,the Fenton oxidation,coagulation and precipitation pilot experiments as well as engineering commissioning and operation of organosilicon wastewater were carried out,and the following conclusions were drawn:（1）According to Fenton,coagulation single factor and orthogonal experiment results,the optimal dosage,the optimal reaction time and p H were obtained.Fenton experiment:the dosage of Fe SO₄·7H₂O and 30%H₂O₂ were 5 g/L and 11 ml/L respectively,the reaction time was 2 h,p H=3,the removal rate of COD was 31.8%;Coagulation experiment:the dosage of PAC and PAM were 250 mg/L and 2.5 mg/L respectively,the reaction time was 20 min,p H=7,and the COD removal rate was 20.2%.（2）When the UASB anaerobic reactor was started,it is necessary to control influent temperature,nutrient dosage and p H in the tank.The optimum water temperature was 30～38℃,nutrients were added according to C:N:P=（300～500）:5:1,p H was maintained between 6.5～7.5,flow rate was maintained at 0.5 m/h.After debugging and stable operation,the COD removal rate was close to 90%,and the effluent COD concentration closed to 1000 mg/L.（3）When A/O pool was started,the water temperature,p H and dissolved oxygen need to be properly controlled:the influent temperature should be controlled to 30℃;Add extra lye to adjust the p H of anoxic tank 6.5～7.5,and the p H of aerobic tank8.0～8.4;The dissolved oxygen of pool A was less than 0.4 mg/L,and that of Pool O was between 2 and 3 mg/L.After the commissioning and stable operation,the removal rates of COD and NH₃-N were between 80%～85%and 75%～80%,respectively.The effluent COD concentration was about 160 mg/L and NH₃-N concentration was less than 30 mg/L.（4）After stable operation of the system,the removal rates of COD and NH₃-N were 98%and 82%,respectively,and the effluent COD concentration was 154 mg/L and NH₃-N concentration was 20 mg/L.By calculating the cost generated in the operation process,it is concluded that the cost of wastewater treatment per ton was 82.4yuan,which has a certain reference function for the same type of organic silicon wastewater treatment.