Tannery waste water Research Papers (original) (raw)

Metals such as nickel (Ni), cadmium (Cd), cobalt (Co), copper (Cu), zinc (Zn), lead (Pb) and potassium (K) are considered essential in trace amounts in water whereas they become harmful or toxic above a certain concentration. Inappropriate treatment of industry effluents e.g. tannery effluents is a major contributor to such water pollution. In the present study, tannery effluents were collected from three different polluted sites of the river Buriganga, Dhaka, and ground water in dry and rainy seasons. The elemental analysis of the samples was conducted using Flame Atomic Absorption Spectrophotometer (FAAS). The concentrations of Ni, Cd, Co, Cu, Zn, Pb and K of tannery effluents were found in the range of 0.08-0.77, 0.98-1.42, 0.11-9.75, 0.75-0.82, 0.006-0.54, 0.05-0.85 and 1.42-21.24 ppm respectively. Concentrations of most of the elements in the water samples were higher than the WHO standards and DoE standards for effluent treatment plants. The concentrations of different metals were varied with the seasons. The dry season had significantly higher contamination loads, which were decreased during the monsoon season. Anthropogenic activities, as well as the variation in river water flow during different seasons were the main reasons for this high degree of water pollution.