Abstract

Chromium (Cr) is used in many manufacturing processes, and its release into natural waters is a major environmental problem today. Low concentrations of Cr(VI) are toxic to human health and living organisms due to the carcinogenic and mutagenic nature of this mineral. This work examined the conversion of Cr(VI) to Cr(III) via electrochemical reduction using gold electrode in an acidic sodium alginate (SA) solution and subsequent removal of the produced Cr(III)-SA by the polymer-enhanced ultrafiltration (PEUF) technique. A solution of SA in nitric acid was used both as an electrolytic medium during the voltammetric measurements and bulk electrolysis and as an extracting agent during the PEUF technique. The electroanalysis of Cr(VI) was performed by linear sweep voltammetry in the presence of acidic SA solution to study its voltammetric behavior as a function of the Cr(VI) concentration, pH, presence of Cr(III), SA concentration and scan rate. In addition, the quantitative reduction of Cr(VI) to Cr(III) was studied through the bulk electrolysis technique.