Experiment Research On Advanced Treatment Of Acrylic Fiber Wastewater

China is the largest producer of acrylic fiber in the world for its productionaccounts for about1/3of the world’s total output, the wastewater generated from theacrylic production process has become a major problem in the field of water treatment.As the representative of the domestic chemical fiber enterprise, The Jilin ChemicalFiber Group is located in China’s northeastern while its production of acrylic fiberaccounts for about40%of national output. The object of this research is the effluentof the original wastewater treatment process in Jilin Chemical Fiber Factory.Combined with the national major projects in water pollution control and managementtechnology of “key technology of emission reduction and demonstration project oftoxic organic substance in Songhua river s heavy pollution industry and the subjectof development of acrylic fiber wastewater biochemical treatment technology andengineering demonstration（2008ZX07207-004-04-01）. This research aimed to findan economic and effective treatment method by investigating the treatment effect ofdifferent methods so that the discharged wastewater could up to the standard. Thetreatment effects and optimal technological conditions of coagulation sedimentation,oxidation coagulation, three-dimensional electrode and advanced oxidation process ofFenton was discussed seriously in order to provide a basis for the renovation projectof wastewater treatment in this factory. The conclusions are as follows：（1） In the coagulation sedimentation experiments, the treatment effect of CPFScomposite coagulants is better than others. COD_Crcan be dropped to about143mg/Lunder the conditions of coagulant dosage600mg/L, coagulant aid dosage8mg/L, pH11, and removal rate of COD_Cris up to about37%. The required cost of coagulant andcoagulant aid is about0.86yuan per ton of wastewater;（2） In the experiment using oxidation-coagulation，O-CF has the best effect for theremoval of COD_Crin wastewater, the lowest COD_Crcan be dropped to about29mg/L.Because the agent is expensive, match usage of O-CF and CPFS can reduce the cost,under the conditions of CPFS dosage600mg/L, coagulant aid PAM dosage8mg/L,O-CF dosage150mg/L, dosing interval120s, PH11, COD_Crcan be dropped below120mg/L, the removal rate of COD_Cris as high as about49%. The cost of coagulationreagent is about3.86yuan per ton wastewater.（3） When acrylic fiber wastewater is treated by three-dimensional electrode, COD_Crcan be dropped from290mg/L to212mg/L under the conditions that applied voltage is20V, electrolysis time50min, pH5. At the same time removal rate of COD_Cris about 27%and power consumption is about1.33kW h per ton of waste water.（4） In the the Fenton senior oxidation experiment, COD_Crcan be dropped to94mg/L under the condition of dealing with water200mL, FeSO₄dosage2000mg/L,H₂O₂dosage1mL/L. The maximum removal rate of COD_Cris58%. The cost offenton reagent is about4yuan per ton acrylic fiber wastewater.（5） Through the comparative analysis of different methods, it can be obtained thatcoagulation sedimentation as advanced treatment method of acrylic fiber wastewateris the most appropriate method. Oxidation coagulation method and Fenton oxidationcan made COD_Crmeet the emission standards, but they can’t be applied to theengineering practice of the enterprise because of the high cost of reagents. The usingmethod of oxidation-coagulant and the combination scheme of reagent still need tocontinue to be studied. The three-dimensional electrode with high energyconsumption can’t be used for the advanced treatment of acrylic fiber wastewater,because that the wastewater can’t be treated meeting the emission standards, and theprocess is complex at the same time.（6） The effect comparison between the lab test of coagulation sedimentation andpilot test of coagulation floatation, combined with the the air flotation performanceadvantages and application advantages, and accroding the example of thereconstruction engineering in wastewater treatment plant of Qifeng Chemical Fiber,study on the application of air flotation devices in the the treatment of acrylic fiberwastewater. The results of engineering commissioning showed that COD_Crremovalefficiency of the acrylic fiber wastewater by secondary treatment effluent using thecoagulation floatation is better, and the average removal rate is about28%up to36%.