Toxic Chromium from Tanneries Pollute Water Resources and Soils of Sialkot (Pakistan)

The present investigation reports the concentrations of total chromium and its species i.e. chromium (Cr (III) and Cr (VI)) assessed in soil, drinking water and effluents of tanneries distributed in ten clusters of Sialkot District, Pakistan. 120 samples consisting 40 samples each of topsoil, drinking water, and composite wastewater were collected from the selected tannery clusters. The chelation extraction, and digestion method followed by atomic absorption spectrometer were used to analyze Cr (VI) and total Cr, respectively in soil, wastewater and drinking water at 427 nm and 540 nm, respectively. The concentration of total chromium, Cr (III), and Cr (VI) in wastewater, drinking water, and soil was found to be in range of (Cr) 16.12-36.83 mg/L, 1.0483-3.1824 mg/L, and 3.45-11.43 mg/kg (Cr (III) 0.97-13.25 mg/L, 0-1.05, and 1.56-9.80 mg/kg, and Cr (VI)11.69-28.61 ppm, 0.83-5.96 ppm, and 2.12-11.85 ppm, respectively. The concentrations of chromium contents are above the National Environmental Standard of Pakistan. It was found that pH above 6 leads to higher concentration of Cr (VI) in the samples due to oxidation behavior. The study recommends the treatment of wastewater before being discharged. (author)