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This paper examines the use of ion exchange resins (IER) to remove arsenic contamination present in drinking water by conducting column studies after a preliminary screening of a number of IER using batch equilibrium tests as well as column tests. The studies were conducted as a function of pH, and less than 10 ppb was achieved from an initial concentration of 200 ppb for As(V) with Purolite A-250 resin, a strong base anion (SBA) type II at a pH of 7.5-8.0, range typically encountered in drinking water supplies. The number of bed volumes that can be treated before exhaustion varies with the influent water quality parameters such as pH, competing ions and influent arsenic concentration.

According to Romanian regulations the used ion exchange resins are classified as hazardous waste, without taking in consideration the application for which they have been used. Considering this approach of the used ion exchange resins, the purpose of this paper is to clarify aspects such as: • their treatment to became non-hazardous waste (depending on applications); • their use in different applications as ion exchange; • their incorporation in agricultural lands. The used ion exchangers from water treatment plants (softening and demineralization) have to not be classified as hazardous waste if the pH is in neutral range.