Acrylic Fiber Waster Treat By Adsorption And Catalytic Oxidation

With the rapid development of acrylic fiber industry, generated in the production process of acrylic fiber wastewater are increasing, due to the complexity of the acrylic fiber production process, complex and in the process of adding raw materials, produce many kinds of by-products, resulting in the acrylic fiber wastewater has the features of complex composition, high concentration of pollutants, toxic and low biochemical characteristics, discharge is not harm and serious. Acrylic fiber wastewater of low biochemical characteristics, it is difficult to directly use the sewage main processing unit biochemical pool for treating method, so we need to look for a feasible and effective method for treatment of acrylic fiber wastewater, improve the wastewater biodegradability, so that it can be carried out smoothly for the next step of the biochemical treatment.However, existing physicochemical biochemical method is difficult to economy and efficiency increase the biochemical properties of acrylic fiber wastewater, this paper examines the catalytic enhanced oxidation combined with activated carbon adsorption method and field and reduce CODcr in wastewater, and improve the wastewater biodegradability. Through experiments, the following conclusions are obtained:1) Comparison of different redox impregnated carbon adsorption in the acrylic fiber wastewater, oxidation modification is better than the reduction modification, the stronger oxidation property of dipping solution, the effect is better, the optimal effect is nitric acid modification, oxidation modification of activated carbon can increase the surface acidic oxygen functional groups, reduction modification can increase the alkaline oxygen containing functional groups, and the stronger oxidizing modified, the acidic functional groups increases obviously; the best conditions for the concentration of nitrate nitric acid modified 0.5 mol·L-1,9 h and 45?, high temperature and high concentration of nitric acid will damage the surface and the hole structure of activated carbon, and reduce the surface area and total pore volume, and the suitable conditions, specific surface area and total pore volume of activated carbon can be increased, and can improve the pore number and average pore size;2) Using nitric acid modified activated carbon for adsorption of acrylic fiber wastewater for optimum adsorption conditions is room temperature, pH is 3, adsorbent dosage for 5% of the quantity of waste water, adsorption time is 3 hours. After adsorption the CODcr removal rate was 86.64%, waste water biochemical by 39.55% increased to 85.69%;3) Use microwave regenerate the activated carbon after adsorption, microwave power is 500 W, irradiation time is 2 min,3 g activated carbon, regeneration there is no significant loss of the adsorption effect of activated carbon after 8 time using, each regeneration of activated carbon loss of 2.03%;4) Through methyl orange simulated wastewater by hydrodynamic cavitation experiment get the optimal operating conditions for the system temperature of 30?, hydraulic retention time is 3 h, initial concentration of methyl orange for 10, pH 3, the input pressure 0.3 MPa, gas-liquid 0.05, cavitation system, micro particles (activated carbon) add can promote the cavitation effect;5) Using the separate hydrodynamic cavitation treatment of acrylic fiber wastewater is not good, when combined with cavitation and adsorption, the waste water CODcr removal rate reached more than 80%, treated wastewater can be biochemical was 89.75%, compared to the adsorption alone can be biochemical 85.47% improved. After cavitation and adsorption in wastewater of typical pollutants of acrylonitrile in the role of hydroxyl radicals decomposed into acetic acid, phenol into methyl benzene, difficult degradation organic transformation to easily degradable organic matter and improve the biodegradability of wastewater.