Effect of Mixing Speed and Time on Dyes Removal through Coagulation

Copyright © 2014 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT: 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. Effect of mixing speed and mixing time is almost same for both flocculants. Maximum dyes removal is at 200 rpm for Polymer A110 which is 86 % and for Polymer 202As is 72.4 % which is at 180rpm. At maximum dyes removal is achieved when the mixing time is 18 min it is 85.6 % and 72.5 % for Polymer A110 and Polymer 202As respectively