Study On Combination Processes Of Iron-carbon Micro-electrolysis&Fenton Oxidation For Silicone Production Wastewater

In recent years, with the silicone products more widely applied, siliconeindustry rapid development. to2010, China has become the world’s leadingproducers of silicone products. Silicone products in the production process, willproduce a large number of industrial wastewater discharge. This complexcomposition of wastewater containing high concentrations of COD, AOX, Cu²⁺,hydrochloric acid and other pollutants, is a high concentration organic wastewater,there is no proven treatment process, has resulted in varying degrees ofenvironmental pollution problems. This research mainly aims at the pretreatmentbefore wastewater biological treatment. Its purpose is to reduce effluent toxicity andconcentration of organic matter, improve water quality conditions and wastewaterbiodegradability. Through organic silicon production wastewater treatmenttechnology literature research, this paper presents the iron-carbon micro electrolysisand Fenton oxidation combined pretreatment this high concentration organicwastewater. Pilot study should include: iron-carbon micro electrolysis, Fentonoxidation of optimum operating parameters and the joint process for optimumoperating parameters and biodegradability after treatment comparison. Underiron-carbon micro electrolysis reaction mechanism and influencing factors, the useof thin sheet iron and granular activated carbon as a material to studymicro-electrolysis. And through the single factor determines the iron-carbon microelectrolysis optimum operating parameters as follows: Iron dosage of150g/L, Fe/C mass ratio of4/1, and the reaction time is120min and the unregulated pH of rawwater （raw water pH of2.3）, and aeration. Under these conditions, COD removal rate of about20%, and the effluent B/C increased from0.16up to0.27. This showsthere is iron-carbon micro electrolysis removal of COD is not high. Its main role isto change the structure and properties of organic matter, make certain difficultbiodegradable chemicals into easy biochemical treatment of the material, therebyimproving wastewater biodegradability.According to Fenton oxidation reaction mechanism and influencing factors,through the single factor determining Fenton oxidation optimum operatingparameters as follows: H₂O₂dosage of1.6ml/L, FeSO4dosage is300mg/L, pHvalue of3, the reaction time was60min. Union during the reaction using sixflocculation mixer at200rpm/min speed stirring, the reaction effluent usingcalcium hydroxide cast adjusted to pH8to10, for coagulation and sedimentation60min. Under these conditions, nearly40%of COD removal, effluent B/Cincreased from0.16up to0.33.Combined Process static tests showed that iron-carbon micro electrolysiseffluent concentration of Fe²⁺362.6mg/L, Fe²⁺concentration sufficient hydrogenperoxide can be added directly to carry out Fenton oxidation tests. By theiron-carbon micro-electrolysis treatment of wastewater effluent Fenton reagentoxidation of orthogonal experiment to determine the effect of various factors ontreatment effect in the order: H₂O₂dosage> time> pH value. Thereby determiningthe optimal combination process operating parameters as follows: Iron dosage of150g/L, Fe/C mass ratio of4/1, pH value of the raw water pH （2.3）, the reactiontime is120min. Treated water through a filter, and then use iron-carbon microelectrolysis generated Fe²⁺Fenton’s reagent reaction to proceed without additionaladjusting pH of wastewater （5.2）,30%H₂O₂dosage of1.2ml/L, reaction understirring75min, and then adding calcium hydroxide adjusted to pH9, coagulation60min. In this optimum operating conditions, CODcr removal rate of about65%,wastewater B/C increased from0.16up to0.45>0.3. After this treatment processwastewater biodegradability is good and fit into the latter part of the biologicaltreatment.