Physicochemical and Bacteriological Assessment of Tannery Effluent from Samaru - Zaria, Kaduna State, Nigeria

Abstract

Physicochemical and bacteriological assessment of tannery effluent from Samaru -Zaria was carried out. A total of six (6) tannery effluent samples (from site A- point of discharge, site B- 20m from point of discharge, site C- 40m from point of discharge, site D- 60m from point of discharge, site E- 80m from point of discharge and site F- 100m from point of discharge) were collected from the Nigerian Leather and Science Technology, Samaru - Zaria, Kaduna State in sterile labeled screw capped bottles. Physicochemical and bacteriological analysis was carried out using standard techniques. The physicochemical analysis revealed the appearance of the effluent to be dark-brown with unpleasant odour. the effluent further revealed the presence and at different concentrations of total solids, total suspended solids, total dissolved solids, total hardness, magnesium, sodium, potassium, iron, manganese, nitrite, nitrate, chloride, fluoride, sulphate, phosphate, cadmium, zinc and copper, chemical oxygen demand (COD), biological oxygen demand (BOD), oil and grease all in mg/L except pH. Bacillus sp had percentage occurrence of 100%, Pseudomonas sp had 83.3%, Flavobacterium, Micrococcus and Staphylococcus sp had 66.7% each, Proteus and Klebsiella sp had 50.0% occurrence each, Streptococcus had 33.3% while Escherichia coli had the least percentage of occurrence of 16.7 from the samples of the tannery effluent analyzed respectively. The highest viable count was observed from site F which is 100m away from the point of discharge and had 4.09 x 10⁷ cfu/ml and the lowest from site A (point of discharge) with 1.2 x 10⁷cfu/ml. The treatment of tannery effluents before discharge into the environment is necessary using biotreatment. This will reduce or eliminate environmental pollutions which could be detrimental to humans, animals and plants.

Keywords: Physicochemical, bacteria, COD, BOD, effluent