Feasibility Removal of THMs Precursors using Al+3 and Fe+3Compounds from Shahrchay River in Urmia, Iran

Among disinfection by products, trihalomethanes (THMs) are known as the main carcinogen compounds that it’s the major precursor is humic compounds. The aim of this study was to investigate the removal of humic compounds using Al and Fe compounds from Shahrchay river water.in Urmia city.
This study was done experimental. Experiments perform in jar test batch reactor in different values of pH, Al and Fe. Also THMs was measured under optimal removal conditions
The optimal dosages of ferric chloride, alum and PACl for removal of humic compound obtained, 10, 30 and 20 mg/L, respectively. The highest removal efficiency was related ferric chloride with 89 %, and removal efficiency for PACl and alum were 88% and 81%. But SUVA (specific ultraviolet absorbance) index decreased less than USEPA permissible limits (less than L/mg m 2) only with ferric chloride.
Ferric chloride can be used for removal of humic acid in water of Urmia Shaharchi river to decreased SUVA index in permission ranges. But the use of aluminum salts may lead to THM formation. Chlorinated treated water with Ferric chloride, approved reduction of the amount of trihalomethanes to USEPA permissible limits (ppb