Optimization of Culture Condition for Biosorption of Lead using Pseudomonas aeruginosa isolated from Gold Mining Site of Anka, Zamfara State

Abstract

Pseudomonas aeruginosa was used as a biosorbent for biosorption of lead from heavy metal-contaminated gold mining soil of Anka, in Zamfara State. The effects on the degree of biosorption by Pseudomonas aeruginosa were studied, including contact time, pH, temperature, biomass load, and agitation speed. The effects of contact time were studied at 24, 48, and 72 hours. Results showed the highest uptake (98.3%) of lead at 48 hours and the least (97.8%) at 24 hours. The effect of pH was studied at pH 3, 4, 5, 6, and 7, with pH 6 recording the highest lead removal of 99.0%, while pH 3 recorded the least percentage biosorption. The effect of temperature was studied at 25, 35, 45, 55, and 65°C, with the highest percentage biosorption (99.3%) recorded at 55°C and the lowest (98.1%) at both 35 and 45°C. The effect of biomass load was studied using different volumes (0.5, 1.0, 1.5, 2.0, and 2.5 mL) of the inoculum; generally, the values obtained did not show variation with changes in biomass load. The effect of agitation speed was studied at 2000, 2500, and 3000 rpm, with the highest lead removal observed at 2000 rpm. Biosorption of heavy metals is an excellent technology and represents a potentially cost-effective way for heavy metal decontamination from the environment.