Organic-iron removal from water supplies

The purpose of the study was to determine if resins or activated carbon presently used to remove organic color from water supplies would also remove organically bound iron. The resins studied were Amberlite IRA 904, Duolite S-37, Dowex 11 and Amberlite IRA 498. The activated carbon used was Atlas Darco. Solutions of fulvic acid, fulvic acid-iron and humic acid-iron were passed through the resin columns. Amberlite IRA 904, Duolite S-37 and Atlas Darco activated carbon effectively removed (100$ removal) fulvlc acid but little fulvic acid-iron or humic acid-iron (35% and 5% respectively) . Dowex 11 and Amberlite IRA 498 were less effective in removing fulvic acid than IRA 904, Duolite S-37 and activated carbon, and would not remove fulvic acid-iron or humic acid-iron. A simple test for organically bound iron was developed and it was found that iron-organic interactions were time dependent. Humic acid-iron reactions were very quick (approximately 4 hours) while fulvic acid-iron reactions were much slower (15 days required for 57% of the iron to be strongly bound). It was found that a strongly bound fulvic acid-iron solution acts very much like a humic acid-iron solution precipitating at a pH of less than 4.7 and that the color increases considerably as the solution ages and the organic-iron binding becomes stronger.Applied Science, Faculty ofCivil Engineering, Department ofGraduat