Removal of surfactant from industrial wastewaters by coagulation flocculation process

Surfactants are among the most widely disseminated xenobiotics that contribute significantly to the pollution profile of sewage and wastewaters of all kinds. Among the currently employed chemical unit processes in the treatment of wastewaters, coagulation-flocculation has received considerable attention for yielding high pollutant removal efficiency. Jar-test experiments are employed in order to determine the optimum conditions for the removal of surfactants, COD and turbidity in terms of effective dosage, and pH control. Treatment with FeCl3 proved to be effective in a pH range between 7 and 9. The process is very effective in the reduction of surfactants and COD, the removals are 99 and 88 % respectively, and increased BOD5/COD index from 0.17 to 0.41. In addition to precipitation coagulation process, adsorptive micellar flocculation mechanism seems contribute to the removal of surfactants and organic matters from this rejection.