Synthesis Of Cellulose-based Flocculation & Decolorization Material And Its Performance On Dye Solution Treatment

Textile printing and dyeing industry is a pillar industry in Zhejiang Province,but also one of the industrial sector discharge of waste water.Textile printing and dyeing industry emits a large number of printing and dyeing wastewater each year,these wastewater with high reducibility,pH instability,biodegradability,The single method is hard to deal with and so on.The current printing and dyeing wastewater treatment methods are mainly membrane separation,chemical oxidation,adsorption,flocculation sedimentation and biological treatment and so on.Among them,the flocculation settling method is an economical and effective water treatment method,flocculation settling method is easy to operate,most of which can remove suspended and slightly soluble contaminants in the printing and dyeing wastewater,but the effect of the dissolved pollutants in the wastewater is not very satisfactory.Adsorption method belongs to one of the physical methods,due to it has the advantages of simple operation,it has a good removal effect of a variety of dyes to deal with,etc.,which occupy a large proportion of the wastewater treatment,most of the adsorption method can remove the solubility of printing and dyeing wastewater Contaminants,while the removal of solid suspended solids ineffective.Therefore,we focus on the effective combination of flocculation and adsorption decoloration,and realize the complementary advantages of the two treatment methods to improve the treatment efficiency of printing and dyeing wastewater.In this thesis,bentonite modified by anionic polyacrylamide(APAM)and bamboo pulp cellulose(BPC)dissolved in sodium hydroxide/urea system were added to prepare cellulose-based flocculation-decolorization composite functional material by free radical polymerization(BPC-g-APAM-bent).The objective factors affecting the flocculation and decoloration of BPC-g-APAM-bent were further studied,the flocculation process was optimized to ensure efficient and stable decolorization and excellent flocculation performance,BPC-g-APAM-bent was applied to the decolorization of Orange II,Basic Red 46 and Reactive Blue 19,and then the BPC-g-APAM-bent was applied to the flocculation treatment of standard kaolin suspension for the process validation.Finally,the optimized BPC-g-APAM-bent was applied to the flocculation and decoloration of printing and dyeing wastewater,The flocculation mechanism of BPC-g-APAM-bent bleaching dye was also determined by adsorption kinetics.The specific research contents and experimental conclusions are summarized as follows:1.Synthesis of cellulose-based flocculation & decolorization material and optimization of the addition processBentonite modified by APAM and BPC dissolved in sodium hydroxide/urea system were added to prepare BPC-g-APAM-bent by free radical polymerization.Orthogonal experiments were designed to optimize the product conditions.The average color removal rates of the optimized prepared BPC-g-APAM-bent on the Orange II,Basic Red 46 and Reactive Blue 19 were 95.4%,99.2% and 99.3% respectively.BPC-g-APAM-bent decolorization performance is relatively efficient and stable.Through the orthogonal experiment of four factors and three levels,the conditions of using the product were optimized.BPC-g-APAM-bent treated with Orange II,Basic Red 46 and Reactive Blue 19 according to the optimized conditions,the average color removal rate reached97.6%,99.2% and 99.9%,respectively.The decolorization performance of BPC-g-APAM-bent was verified by the treatment of three dyes.2.The bleaching performance of BPC-g-APAM-bentWe studied the decolorization of three dyes with bentonite,APAM,BPC-g-APAM and the product,respectively.It is found that the color removal rates of APAM and BPC-g-APAM are very low,the color removal rate of bentonite is high,and the color removal rate of BPC-g-APAM-bent is the highest.Bentonite has good decoloration of the dye and BPC-g-APAM-bent has particularly good decoloration of the dye.It is demonstrated that the bleaching performance of BPC-g-APAM-bent is enhanced on the basis of Bentonite and the bleaching performance of BPC-g-APAM-bent is excellent.3.Flocculation performance of BPC-g-APAM-bent and BPC-g-APAM-bent dealt with printing and dyeing wastewaterThe treatment of 200 mg/L standard kaolin suspensions with bentonite,APAM,BPC-g-APAM and BPC-g-APAM-bent was studied,respectively.It was found that the turbidity removal rate of APAM was poor,the turbidity removal rates of bentonite and BPC-g-APAM were higher,and the turbidity removal rate of BPC-g-APAM-bent was the highest.It shows that BPC-g-APAM-bent has excellent flocculation performance.BPC-g-APAM-bent can maintain the decolorization performance of the original BPC-g-APAM while enhancing the decolorization performance.It shows that BPC-g-APAM-bent has excellent flocculationperformance.BPC-g-APAM-bent has high chemical oxygen content removal rate,BPC-g-APAM-bent can better remove the chemical oxygen content in the printing and dyeing wastewater.