Estudo da eficiência do processo de coagulação/floculação na tratabilidade de águas residuárias têxteis

Abstract

This study evaluated the efficiency of organic coagulants like seeds of Moringa oleifera Lam extracted in saline solutions of sodium chloride and potassium chloride1,0 (MO-NaCl and MO-KCl, respectively) and inorganic coagulants like aluminum sulfate and ferric chloride to the treatment of textile wastewater. Initially, it has been evaluated the best pH for each coagulant studied to then optimize the concentration of the coagulants and settling time. For this finality, it has been used velocity of rapid mixing (VMR) and slow (VML) at 100 rpm and 20 rpm, respectively and time of rapid mixing (TMR) and slow (TML) for 2 minutes and 20minutes, respectively. The parameters analyzed were pH after treatment, absorbance at a wavelength of maximum absorption for each dye present in the wastewater (Procion Orange HER and Procion Red HE-7B), color, turbidity and COD. In the test for optimization of coagulants concentration and settling time, also was evaluated the amount of sludge generated at each concentration studied. Thus, organic coagulants showed superior results in comparison with inorganic coagulants in the treatment of textile wastewater, especially MO-KCl, which showed removal of 86,8% for absorbance of the dye Procion Orange HER, 75,65% for absorbance of the dye Procion Red HE-7B, 70,67%forcolor, 85,97% for COD and 64,07% for turbidity. Based on the results obtained, MO-KCl presented a promising coagulant in the treatment of textile wastewater.