Quantitative Assessment of Some Toxic Elements and Physicochemical Parameters in Wastewater of Dyeing Industry: A Case Study

--------------------------------------------------------------------------------------------------------------------------------------------Abstract The current study aims to examine the concentration of some toxic elements such as, cadmium (Cd), chromium (Cr), lead (Pb) and nickel (Ni) and physicochemical parameters such as electric conductivity (EC), pH, total dissolved solids (TDS), and biological oxygen demand (BOD) in the wastewater of dye manufacturing, textile dyeing, and small dyeing industries. The concentrations of Cd, Cr, and Ni in wastewater samples of these industries were significantly higher than the permissible limits set by WHO for toxic metals in industrial wastewater. The highest level of EC was observed in wastewater samples of the small dying industry as compared to the other two types of industries. The BOD of the investigated wastewater samples was almost two to three-times exceeded than the suggested threshold level recommended by EPA for industrial wastewater. The elevated BOD levels might be due to the presence of the excess level of organic matter in wastewater discharged from the various activities of industries.