Electrochemical investigation of hazardous metals released from fly ash

Abstract

The paper discusses the utilization of stripping voltammetric methods for the determination of Zn, Pb, Cr, Co and Ni in extracts from fly ashes. For this purpose, the most sensitive anodic stripping voltammetric (ASV) procedure for Zn and Pb quantification in acetic buffer has been selected. Traces of Ni, Co and Cr(VI) were determined by means of catalyticadsorptive stripping voltammetry (CAdSV) with nioxime and nitrite (Ni and Co) or with DTPA and nitrate (Cr). It was observed that relatively high amounts of surface-active substances or other dissolved organic matter (DOM) present in the extracts severely interfered in the determination of the investigated metals ions by blocking the electrode surface and suppressing the stripping voltammetric response of metal ions, especially in ASV. Therefore, the methods of destroying DOM using ultraviolet irradiation or through their in situ removal via adsorption on the Amberlite XAD-7HP resin were examined and applied.