Effect of pH and Temperature on The Removal of Heavy Metals by Autochthonous Bacteria from Water in a Gas Flaring Environment

Heavy metal pollution of water caused by gas flaring has turned out to be a common environmental challenge across the globe due to its toxic effect and accumulation through the food chain. This study was aimed at determining the effect of pH and temperature on the removal of heavy metals present in polluted water samples obtained from gas-flaring environments, using indigenous heavy metal-resistant bacteria. Di¬gestion of samples was carried out and heavy metal analysis was performed using the Atomic Adsorption Spectrophotometer. Conventional methods were used to isolate and identify the bacteria isolates up to species level. A total of 120 bacteria isolates were obtained and screened for heavy metal resistance. Three isolates were selected based on their tolerance to a maximum concentration of 500 ppm of a mixture of Pb, Cr, and Cd. These resistant isolates were subjected to molecular identification using the 16s rRNA gene sequencing and identified as Klebsiella pneumoniae, Klebsiella aerogene, and Salmonella bongori. The effect of pH on the removal of heavy metals by the resistant isolates was studied at a pH range of 5, 7 and 9 at 37℃ for 48hours, and the effect of temperature at 35℃, 55℃ and 65℃ at a pH of 7 for 48hours. The highest heavy metal re¬moval was recorded at pH 7 35 and 65℃. This study reveals that an optimum pH of 7 and temperatures of 35 and 65℃ can be used for the removal of Pb, Cr, and Cd from polluted water in gas-flaring environments.