REMOVAL OF DYES FROM TEXTILE WASTEWATER USING CHEMICAL OXIDANTS

Abstract

Textile dye wastewater is known to contain strong color, high pH, temperature, COD, and low biodegradability, especially the effluent from dyeing stages and finishing process. Strong color is caused by highly structured polymers which are very difficult to decompose biologically and has the tendency to combine with high dissolved solid content that leads to high turbidity of' the waste effluent. The renwval of dyes (color) is therefore a challenge to both textile industry and wastewater treatment facilities because if not removed, will result in considerable disturbance to the ecological system of the receiving waters. This research investigated the efficiencies of different chemical oxidants for decolorizing the reactive cibacron textile dyes in synthetic solutions and real textile wastewater sample. The objective of this study was to determine optimum treatment conditions (oxidant dose, oxidation temperature and reaction time) and selecting effective oxidizing agent to achieve maximulll dye removal. Both chemical oxidants: sodium hypochlorite (NaOCl) and calciunl hypochlorite considered in this research have not been implied for textile wastewater treatment yet and hence gives an edge to this research. Now these oxidants provided color reduction. The results suggested that Ca(OCl)2 was most effective treating both synthetic dye solution and real wastewater sample with dye removal up to 95% at all temperatures. NaOCl on the other hand, was most efléctive orange dye solution with removal efficiency up to 90%. Both dyes showed removal efficiency up to 990/0 for black dye solutions. A research goal was to recommend a zero energy model the treatment of textile wastewater effluent under optimum conditions: dosage of 0.2 g/L or NaOCl dosage of 2.2 gil-, at 500C and 30 minutes. This will meet the need of an etTicient, inexpensive technology to rennediate environinental problems caused by the dyes present in textile wastewater