Removal of Colour from Textile Wastewater Using Two- Step Coagulation Process

The waste water from the textile dyeing industry pr oduces large amount of coloured water and this need s to be treated before discarding in the ecosystem. There a re various treatment technologies to remove colour from this wastewater which includes the most primitive yet ef fective method of coagulation-flocculation. In this research, inorganic coagulants like Alum (t rivalent) and ferrous sulphate (bivalent) were appl ied on commercial dyes Congo Red and Direct green 41 at different pH values of 8,9,10. Various parameters suc h as colour removal percentage, pH changes, TDS (Total Dissolved Solids), settled sludge volume has been evaluated . It has been estimated that though FeSO4 is the bett er coagulant for colour removal but somehow it prod uced an anesthetic colour to the residual water in compa rison to Alum. Moreover Congo red being less complex in structure is removed more effectively than Direct green 41.