Physico-chemical properties of tannery effluents from Challawa industrial area in Kano and evaluation of bioremediation potentials of Spirogyra porticalis and Chlorella vulgaris on the effluents

Abstract

Discharge of industrial effluent in aquatic environment is a serious threat to life due to toxic heavy metals. Algae can be used as cheap bioremediation agents in comparison to conventional technologies. The present study was conducted to evaluate the bioremediation potential of two algal species (Spirogyra porticalis and Chlorella vulgaris) for the removal of Lead from two tannery industries (M Tannery and G Tannery), located in Challawa Industrial Area. Temperature, EC, TDS, DO and BOD were measured. In G Tannery, Spirogyra porticalis had the highest affinity for Lead which was 51%, 55% and 51% at 3, 6 and 9 weeks interval respectively while Chlorella vulgaris affinity for Lead was 40% 45% and 45%. In M tannery, Chlorella vulgaris had the highest potential to remove Lead from the effluent, which was 90%, 86% an 90% while Spirogyra porticalis affinity for Lead was 10%, 41% and 10%. Temperature ranged from 30-31˚C which might be as a result of ambient temperature. The pH of both tannery effluents did not differ significantly (p=<0.5) and it was not within the maximum permissible limit of 6.5-8.5. EC of M Tannery was a little higher than that of G Tannery (8.417±0.26, 6.920±0.050) which were below the permissible limit. TDS of M tannery was higher than that of G Tannery 1919.0±68.46mg/L, 1916.0±61.94mg/l which were not within the permissible limit. DO content were within the permissible limits of 6.4mg/L. BOD of both effluent samples were below the permissible limit of 4mg/L. This research shows that both species are suitable for bioremediation and are also tannery specific.

Keywords: Bioremediation, Effluent, Tannery, Spirogyra porticalis, Chlorella vulgaris