Bio-Remediation Of Cu, Ni And Cr From Rotogravure Wastewater Using Immobilized, Dead, And Live Biomass Of Indigenous Thermophilic Bacillus Species.

Abstract

Heavy metals resistant thermophilic bacilli were isolated from Ma’een hot springs in Jordan and used as immobilized, dead and live biomass for bioremediation of heavy metals present in the wastewater effluent of Jordan Rotogravure Establishment (JRE). Four species of bacillus were isolated and identified. They include: Bacillus sphaericus, Bacillus pumilus, Panibacillus alvae and Geobacillus sterothermophilus. They all exhibit resistance to at least 100 mg/L Cupper (Cu), nickel (Ni), and chromium (Cr). A significant difference in Cu (p= 0.001), Ni (p= 0.013) and Cr (p= 0.035) mean biosorption capacity was recorded between Bacillus species. Heavy metals were reduced more efficiently with immobilized cells (p˂ 0.05). B. sphaericus have the highest ability to adsorb Cu (87.5%) and Ni (72.8%) present in rotogravure effluents in comparison to B. pumilus, Panibacillus alvae and G.sterothermophilus that showed 81%, 65.4% and 79.6% for Cu and 62.4%, 59% and 65.6% for Ni, respectively. A maximum removing efficiency was recorded for Cr by B. pumilus (86.5%) in comparison to 83%, 78.3% and 82.7% estimated for B. sphaericus, Panibacillus alvae and G. sterothermophilus respectively. Although the overall sorption efficiency doesn’t vary significantly within the temperature range 37°C70°C, thermophilic bacilli exhibit a maximum metal binding capacity at temperatures 60°C and 70°C. The affinity of Bacillus for heavy metals adsorption was found to be; Cu> Cr> Ni for B. sphaericus and Cr> Cu> Ni for other Bacillus species.