Evaluation of Physiochemical Parameters and Some Heavy Metals from Tannery Effluents of Sharada and Challawa Industrial Areas of Kano State, Nigeria

Abstract

The evaluation of physicochemical parameters and some heavy metals was carried out from six different tannery companies at the industrial areas of Challawa and Sharada, using standard procedures. Temperature, pH, conductivity and total dissolved solids(TDS) were determined using portable digital hand logging meter. The sulphate, phosphate, nitrate, arsenic contents were determined using UV Spectrophotometer, while chloride, dissolved oxygen (DO) and biochemical oxygen demand (BOD) contents were determined using titrimetric method, and the heavy metals by atomic absorption spectrometry. The mean temperature of the water ranged from 36.00 – 39.670C, pH: 2.63 – 9.33, conductivity: 336.33 – 12351.67μS/cm, TDS: 166.73 – 6017.67mg/L, sulphate: 114.00 – 466.67mg/L, phosphate: 0.29 – 12.80mg/L, chloride: 58.66 – 1577.87mg/L, nitrate: 6.03 - 33.43mg/L, DO: 2.60 – 21.27mg/L and BOD: 0.77 – 12.33mg//L. Water samples from the tannery effluents contained higher levels for both physicochemical parameters and heavy metals in untreated than treated. Cadmium and nickel were within the WHO limit for both treated and untreated while arsenic was within the limit for only treated effluent. Chromium and lead were above the WHO limit for both treated and untreated effluent. The parameters studied showed variations within the tannery companies and this may affect the Challawariver where this effluent is discharged which can have long term health effect on the aquatic animals and humans that depend on the river water for their daily activities.

Keywords: Biochemical Oxygen Demand, Dissolve Oxygen, Heavy Metals and Effluents