Effect of Potassium Permanganate on Effectiveness of Chitosan in Removing of Turbidity and Fecal Coliforms from Wastewater

Chitosan, as a coagulant is used in water and wastewater treatment. It has similar performance in comparison with other conventional coagulants, and doesn’t have any disadvantages of them. However, its bactericidal property is lower than the metal based coagulants. In this study the potential synergistic effect of potassium permanganate, as a powerful oxidant, on the Chitosan fecal coliforms inactivation and turbidity removal has been investigated. Synthetic wastewater samples were prepared by mixing tap water with Bentonite and adding pure culture of fecal coliforms that provided by biological laboratory of Tehran University of Medical Sciences. After preparing synthetic samples of the wastewater and determining its turbidity and fecal coliforms concentration, various doses of Chitosan and Potassium Permanganate individually and in combination with each other, were injected to the samples. Afterwards supernatant of jar reactors were investigated for turbidity and fecal coliforms removal. Simultaneous use Chitosan and potassium permanganate has higher removal efficiency than the individual using of them. Highest applied combined dose (3 mg / L Chitosan and 1.5 mg / L potassium permanganate) reduced fecal coliform to a level less than 100 MPN/100mL, which is equivalent 4 log-inactivation of fecal coliforms. Simultaneous use of Chitosan and potassium permanganate in tertiary treatment of wastewater can led to produce lower turbidity, as well as higher microbial quality in the effluent, which can reduce the amount of required disinfectant, consequently disinfection by products formation lowered very much.