The physicochemical and microbiological quality assessment of Maddhapara hard rock-mine discharged water in Dinajpur, Bangladesh

Abstract

Mining water quality must be monitored regularly to assess the potential impact on local water resources, surface water, and groundwater. This report determined the physicochemical, heavy metals content, and microbiological characteristics of mining drainage water and paddy field water in the surrounding area to determine the extent of pollution. The physicochemical water quality parameters of mine water, including pH, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), and salinity, was 6.4–7.6, 100–600 s/cm, 25–369 ppm, 9.0–12.10 ppm, and 0.02–0.29 ppt, respectively. When six metals (Pb, Cr, Ni, Zn, Cu, and Fe) were compared as potential contaminants with various international water pollution indices such as the heavy metal pollution index (HPI), heavy metal evaluation index (HEI), and degree of contamination (DC), this water was found to be contaminated with Pb, Ni, Zn, and Fe. The microbial water quality index of the mine water was found to be within the WHO recommended level, but the presence of sulfur-reducing bacteria was detected in all the water samples tested. The presence of many sulfate-reducing bacteria in water sources can lead to higher levels of free sulfur, which can cause dermatological problems in humans.

Keywords

• Hard rock mine drainage water
• Water quality
• Pollution index
• Sulfur reducing bacteria
• Fecal indicator bacteria