Abtrennung von Arsen(V) aus Grundwasser mittels Ionenaustauscher

Several WOFATIT ion exchangers were tested for the extraction of arsenic(V) of model solutions of groundwater. For this purpose the behaviour of strongly and weakly basic anion exchangers were investigated. These had the following anchoring groups on a styrene-divinylbenzene matrix: Trimethylammonium (SW31, SZ30), dimethylhydroxyethylammonium (SBK, SL 30), methyl-N-triethylamine (SN 36L), dimethylamine (AD 41), di-N-butylamine (Y96), iminodiacetic acid (MC 50), N-methyl-aminoglucitol (MK 51), N-methyl-aminomethyl-phosphonic acid (Y80) and mercaptane (FCM 91-95). The experiments were carried out with pure arsenate solutions as well as with those containing other salts. No special affinity for arsenate was found for the group of the chelating resins. The most suitable resin was WOFATIT SBK (strongly basic, get form, type II). The extraction of arsenate was achieved even from solutions with a thousandfold excess of chloride and sulfate. A favourable extraction was possible from weakly basic solutions, because hydrogenarsenate ions exists in this pH range. Several charges of the WOFATIT SBK resin with different cross linkages were investigated to optimize the results.