The present study investigated biosorption of Pb (II) and Zn (II) using a heavy metal tolerant bacterium Oceanobacillus profundus KBZ 3-2 isolated from a contaminated site. The effects of process parameters such as effect on bacterial growth, pH and initial lead ion concentration were studied. The results showed that the maximum removal percentage for Pb (II) was 97% at an initial concentration of 50 mg/L whereas maximum removal percentage for Zn (II) was at 54% at an initial concentration of 2 mg/L obtained at pH 6 and 30 °C. The isolated bacteria were found to sequester both Pb (II) and Zn (II) in the extracellular polymeric substance (EPS). The EPS facilitates ion exchange and metal chelation-complexation by virtue of the existence of ionizable functional groups such as carboxyl, sulfate, and phosphate present in the protein and polysaccharides. Therefore, the use of indigenous bacteria in the remediation of contaminated water is an eco-friendly way of solving anthropogenic contamination.

Novel cellulose acetate-based anion exchange membranes (CA-AEM) are successfully synthesized via gamma radiation grafting as a possible renewable alternative to commercial AEMs. Using CA film precursors with degree of acetylation of 2.5, the synthesized AEM shows a high ion exchange capacity of 2.15 mmol g −1 obtained at high degree of grafting of 45%. It was determined using thermogravimetric analysis that the radiation-grafted CA-AEM has stable amine functional groups under oxygen environment within the normal operating temperature range of alkaline fuel cells. The CA-AEM also exhibits appreciable performance over a range of temperatures, with a highest ionic conductivity of up to 0.163 S cm −1 depending on the synthesis parameters. Results revealed that membranes prepared using gamma radiation dose of 31 kGy and above are susceptible to mechanical and dimensional instability due to increased water uptake and degree of swelling. Further study should consider the balance between grafting parameters and the desired hydrophysical properties.