Treatment of textile wastewater using a natural flocculant

The physicochemical treatment of wastewater is of substantial interest, especially when conventional treatments by biological processes are not amenable. Among the current chemical processes used for industrial wastewater treatment, coagulation-flocculation has received a large attention for high pollutant removal efficiency. This paper summarizes the results of a textile wastewater treatment process aimed at the destruction of colour by coagulation-flocculation process and using an organic natural flocculant: tannic substances. Jar-test experiments were carried out in order to determine the optimum conditions for the removal of organic matter and color. Treatment with studied flocculent (Polysep3000) proved to be effective in a wide pH range (pH < or = 10), very effective in removing the color (96 %) and a fraction of the COD (40-50 %) from the textile wastewater. Polysep3000 is compared to Al2 (SO4)3 and FeCl3 for sludge production. Polysep3000 seems to be suitable for yielding a high removal of color (> 90%) and corresponding low volume of settled sludge.