Research For The Decoloring Teatment Of Textile Wastewater By BH1Coagulation Decolorant

With the improvement of people’s living standard and the expansion of exportmarket, China’s textile and dyeing industry has developed rapidly, with the scale oftextile and dyeing industry was already at the top in the world, problems of waterenvironment pollution caused by textile wastewater araised.According to statistics,China’s textile wastewater have become a major source of wastewater. Organicsubstance and color were the main pollutant in textile wastewater, also were theemphasis of the treatment.Coagulation was one of the main methods in dyeing wastewater treatment, in thetreatment the kinds of coagulants played an important role. In this paper a newdeveloped BH1coagulation decolorant, and the other two commonly used coagulantsorganic decolorant agents and polymerized aluminum chloride were researched in thesimulation and actual textile wastewater (textile wastewater of a factory in Qingdao)treatment. Through testing the index of color, the performance of each coagulants inprocessing different kinds of simulation dyeing wastewater and actual textilewastewater, the optimal pH and dosages were found and the feasibility andcompetitiveness of BH1coagulant in practical was discussed.Primarily, experiments of the simulated single dyeing wastewater were done tostudy the decoloration effect of coagulation. Result showed that BH1coagulationdecolorant didn’t work well to cationic dyeing wastewater, the efficiency ofdecolorization was only15.3%, for the rest4kinds that is reactive, disperse, acidic andneutral dyeing wastewater it worked well. The efficiency of decolorization were:97.1%,99.2%,88.7%,93.4%, the optimal pH were8,10,8and7, and the optimaldosages were0.6mL/L,0.4mL/L,0.4mL/L and0.4mL/L;There was no treatmentefficiency for organic decoloring agent to cationic dyeing wastewater, color didn’t dropwhen organic decolorizing agent dosage increases, it didn’t worked well to dispersedyeing wastewater, the efficiency of decolorization was only4.8%,for the rest3kindsthat is reactive, neutral and acidic dyeing wastewater it worked well. The efficiency of decolorization were:91.4%,90%,90.2%, the optimal pH were9,10and8, and theoptimal dosages were50mg/L,50mg/L and50mg/L;There were no obviousdecoloring efficiencies for PAC to both cationic dyeing wastewater and disperse dyeingwastewater, the efficiency of decolorization ware11.5%and0.43%,while for the rest3kinds that is reactive, neutral and acidic dyeing wastewater it worked well. Theefficiency of decolorization were:84.7%,73.9%,66.7%, the optimal pH were9,10and8, and the optimal dosages were100mg/L,100mg/L and120mg/L. Thus, BH1coagulation decolorant applied to greater range than organic decolorizing agent andPAC in the decoloring treatment of simulated single dyeing wastewater, and its effectof decolorization was better.Obtained from the decoloring research of practical textile wastewater, theoptimal pH of BH1coagulation decolorantion dyeing wastewater was7,while theoptimal chemical dosage was2.5ml/L, in this case, the removal efficiency of colorwas80%, chroma was40times, the cost of decoloring treatment was1yuan/m3,andthe effluent reached the Ⅱlevel discharge standard of water pollutants for dyeing andfinishing of textile industry of Shandong province(DB37/533－2005)in table1. Forthe organic decoloring agents, the optimal pH was8, the optimal dosage was300mg/L,in this case, the removal efficiency of color was75%, chorma was50times,the cost of decoloring treatment was2.4yuan/m3,the effluent could reach the Ⅱleveldischarge standard of water pollutants for dyeing and finishing of textile industry ofShandong province(DB37/533－2005) in table1.For the PAC，the optimal pH was8,the optimal dosage was800mg/L, in this case, the removal efficiency of color was62.5%, the chroma was75times,the effluent couldn’t reach the Ⅱlevel dischargestandard of water pollutants for dyeing and finishing of textile industry of Shandongprovince(DB37/533－2005) in table1.Therefore, compared with Organic decolorant and ferric chloride,BH1coagulation decolorant has the characteristics of high efficiency of declolorization,low coast, simple operating, and good settlement. Whether in economic or intreatment effect BH1coagulation decolorant has higher competitiveness.