Removal of heavy metal (Cu2+) by Thiobacillus sp. and Clostridium sp. at various temperatures and concentration of pollutant in liquid media

Abstract

This research was conducted to remove heavy metal Cu2+ using bioremediation method with the utilization of mix culture of bacterium Thiobacillus sp and Clostridium sp. It started with the cultivation of artificial liquid growth media, Stone Mineral Salt solution (SMSs) using temperature (oC) and pollutant concentration of heavy metal Cu2+ (ppm) as the test parameters. The analysis was conducted with Atomic Absorption Spectrophotometry (AAS) to determine the concentration of heavy metal Cu2+ at the beginning and end of the research in order to calculate its removal efficiency. The exponential phase of mix bacterial culture growth was observed on day 5 with a pH value of 7. Furthermore, the culture was discovered to have the ability to live in several temperatures (oC) of 20, 25, 30 and 35, and remove heavy metal Cu2+ at 89.10%; 91.27%; 92%; and 90.27% respectively. The results also showed that at a contact time of 48 hours, the temperature of 30oC, and Cu2+ pollutant concentration of 25, 50, 75, 100 ppm, the mix bacterial culture could remove the pollutant up to efficiency above 90%. Moreover, a higher concentration of the pollutant in liquid media was found to lead to lower efficiency of removal, but at a value above 90%. Therefore, the use of biotechnology approach in this research is expected to give a scientific contribution to the processing of wastewater containing heavy metal Cu2+.