Textile wastewater treatment using low-cost adsorbent aiming the water reuse in dyeing process

The aim of this work was to study the feasibility of treating textile wastewater by adsorption process using low-cost adsorbent. Sludge from textile effluent treatment was thermal and chemical activated and used to uptake the dye RR141 under different conditions of dye concentration, initial pH of the solution and chemical activation. The results demonstrated that the adsorbent TSC-2, activated with 0.1M H2SO4, showed higher surface area, and consequently, higher adsorption capacity compared to the PTS (without activation) and TSC-1 (activation with 1.0M CH3COOH) adsorbents. In addition, the adsorption process can be conducted with no pH adjust, since the adsorbents have a buffer characteristic. The kinetics results indicate that the pseudo-second-order model can satisfactorily predict the adsorption process. The equilibrium adsorption data were best fitted to the Langmuir model and the results indicate that the presence of electrolytes increased the effect of the temperature on the adsorption equilibrium. The maximum adsorption capacity (30.0 mu mol g(-1)) was obtained using TSC-2 adsorbent at 45 degrees C, initial pH 7.0 with the addition of 50 g L-1 NaCl. In addition, the treated water by adsorption was used in the dyeing process, obtaining a small color difference (Delta E* values < 1.5) when compared to the standard dyeing process.