ELIMINATION OF TRACE HEAVY METALS FROM DRINKING AND GROUND WATER BY MEANS OF WEAKLY BASIC ANION EXCHANGERS

摘要

Weak base anion exchangers exhibit a unique selectivity for adsorption of heavy metals like mercury, copper, lead, zinc, nickel, cadmium. Furthermore, some types of exchanges show a marked preference of chromate over sulphate anions. Application of the respective ion exchange processes may, therefore, offer a promising way to remove traces of hazardous heavy metals very efficiently from the raw water of drinking water supplies. The respective ion exchange processes have been demonstrated both in the laboratory and semi-technical scales for the elimination of heavy metal cations (cadmium, mercury, lead, nickel) and of chromate anions from spiked tap water and contaminated ground waters. In all cases the effluent concentrations of filters could be decreased (far) below the parametric values of the European Drinking Water Directive.