Afshin Takdastan - Department of Environmental Health and Environmental Technology, Research Centre, Ahvaz JundiShapur University of Medical Sciences, Ahvaz, Iran
Naghmeh Orooji - Grad. M.Sc. Student of Applied Chemistry, Islamic Azad University,Omidieh Branch, Ahwaz, Iran
Gholamreza Raeesi - Quality control management and health monitoring of Ahwaz Water and Wastewater Company

Chitosan, a natural biopolymer,biodegradable, nontoxic, high molecular weight, linear cationic polymerwas evaluated for its ability to be used as a coagulant to treat water for potable use.Chitosan is a biodegradable cationic polymer derived by de-acetylation of chitin. This study aims to investigate the effect of chitosan as a coagulantaidsfor improvement of poly aluminum chloride coagulant in removing the turbiditiesfrom drinkingwater.This study conducted in the laboratory using jar test device in water treatment of Ahvaz.Chitosan was tested as a natural coagulant in the removal of the turbidity of Karoon water to replace inorganic coagulants ( PAC) having hazardous effects. Jar test was performed to test some factors that may affect the coagulation process. The factors tested were dose of coagulant (0-22mg/L), initial pH (5-9), type of oagulant chitosan versus PACcoagulants), and thechitosan solvent.Optimal pH for removing the turbiditieswas observed in pH=8. Optimal dosage of poly aluminum chloride together with chitosan was obtained 5 mg/L and 0.02 mg/L respectively. Under optimal conditions, using chitosan could reduce about 50% of concentration of polyaluminum chloride coagulant.WhenPAC concentration was 10mg/L, by adding 0.02mg/L of chitosan to the process, maximum turbidity removal was %99.16.Results indicate good performance of chitosan as a coagulantaidsfor removing the turbidities from drinkingwater.

Ahvaz water treatment, Turbidity,Chitosan,Poly aluminum chloride