Determination of Optimum PH and Dosage of Flocculants and Coagulants for Dyes Removal from Dyebath Effluent

It is difficult to treat textile wastewater to a satisfactory degree because of high chemical oxygen demand COD, Biochemical oxygen Demand BOD, Suspended solids (SS), conductivity and highly intense colours. Colour removal from textile waste water has gained considerable attention these days. Coagulation-Flocculation is a frequently used physiochemical treatment method to decolorize textile effluents and reduce the total loads of suspensions. Jar Test apparatus is used to conduct the research work. The study focuses on determining the effect of coagulation and flocculation, optimum dosage and PH of coagulant and flocculant on the removal of reactive textile dyes from the dye bath effluent of a textile industry. In dye bath effluent two reactive dyes are present named Sumifix Supra Red E-XF gran. and Sumifix Supra Yellow E-XF gran. in ratio 0.55:0.45.Dye bath effluent has initial pH of 11.Alum is used as a primary Coagulant and two flocculants named Polymer A110 (anionic) and Polymer 202 As (cationic) are used as flocculant aids. Optimum dosage for anionic Polymer A110 is 8 ml in combination with 2 g/L of alum and it gives 84 % dye removal while for cationic polymer optimum dosage is 10 ml in combination with 2 g/L of alum and it gives 71.5 % dye removal. Effect of mixing speed and mixing time is almost same for both flocculants.