Evaluation of tannery effluent content in Kano metropolis, Kano State Nigeria

A field experiment was carried out to evaluate heavy metals and physiochemical concentration of tannery effluents from Kano metropolis. Fifteen samples from five selected tannery industries from Sharada and Challawa industrial estate were collected and determined for heavy metals using atomic absorption spectrophotometric method (AAS) and the result of the study showed that the range mean and standard deviation values for chromium (Cr), lead (Pb), iron (Fe) and copper (Cu) were found to be 3.33 ± 0.74 - 5.79 ± 0.96 mg/L, 0.67 ± 0.07 - 3.10 ± 1.07 mg/L, 3.53 ± 1.06 - 8.12 ± 0.69 mg/L, and 0.82 ± 0.53 - 1.51 ± 0.91 mg/L, respectively. The physiochemical values were pH 3.96 ± 1.22 - 10.60 ± 2.49, conductivity, 1554 ± 17.05 - 11410 ± 414.32 μs/cm; total suspended solid, (TSS) 1026.00 ± 170.01 - 3365.60 ± 112.63 mg/L and total dissolved solid (TDS) was 1585.00± 49.53 - 7250.00 ± 73.73 mg/L. With exception of Fe in all sites and Pb in S4, values for the other metals were above the maximum permissible limits of both the Federal Environmental Protection Agency of Nigeria (FEPA) and World Health Organization (WHO). The values for TDS for S4 and pH value for S1 to S3 were within allowable limits, but conductivity and TSS values were above the allowable limit. These findings render the effluents harmful to the environment, and there is the need to take practical steps to avoid pollution and impending health hazard.   Key words: Concentration, contamination, effluent, heavy metal, physiochemical, sewage, tannery.