Study On The Deep Purification And Recycling Of Acrylic Fiber Wastewater

In this dissertation, according to the idea of "source management",acrylic fiber wastewater was treated by combined treatment process of coagulation sedimentation and physical adsorption. The conditions of flocculation sedimentation, coagulation sedimentation, physical adsorption and regeneration of activated carbon were investigated and optimized. The mechanism of flocculation sedimentation, coagulation sedimentation and physical adsorption were prelimilarily discussed by means of Zeta potential analysis, FESEM observation, and laser particle size analysis. The main research work includes:(1) Acrylic fiber wastewater was treated by simple flocculation sedimentation. Taking the turbidity of wastewater as the main index, PAC was selected as the more appropriate flocculant and the flocculation sedimentation process conditions were investigated and optimized by single-factor and orthogonal experiments. The repeated experiments results under the optimum conditions showed that the average turbidity of treated water sample was 0.51 NTU with turbidity removal rate of 86.64%.(2) Acrylic fiber wastewater was treated by coagulation sedimentation using PAC as flocculant, CPAM as coagulant. Taking the turbidity of wastewater as the main index,the coagulation sedimentation process conditions were investigated and optimized by single-factor and orthogonal experiments. The repeated experiments results under the optimum conditions showed that the average turbidity of treated water sample was 0.22 NTU with turbidity removal rate of 96.30%.(3) Activated carbon static physical adsorption: Taking the CODcr of wastewater as the main index, 4# activated carbon (produced from bituminous coal) was selected as the more appropriate physical adsorbent and the adsorption process conditions was investigated and optimized. The repeated experiments results under the optimum conditions showed that the average turbidity was 0.13 NTU with turbidity removal rate of 97.81% and the average CODcr was 10.3 mg·L-1 with CODcr removal rate of 85.4%.Both the parameters can meet the technical requirement of the reused acrylic fiber wastewater (turbidity less than 1NTU and CODcr less than 50mg·L-1).(4) Heating at low temperature in Muffle furnace (air environment) was selected as the more appropriate regeneration method when regenerate saturated activated carbon and the regeneration conditions was investigated and optimized. The experiments results under the optimum conditions showed that the comprehensive recovery rate of activated carbon after regeneration can all reach more than 70% when recycling 1 to 3 times.(5) The cost of the "coagulation and physical adsorption" process was preliminarily calculated and the results showed that the cost was 0.45 yuan/ton acrylic fiber wastewater when the reused 4 times which performed strong cost advantage.