Living biomass supported on a natural-fiber biofilter for lead removal

Living biomass biofilters constitute an excellent alternative for heavy metal bioremediation. In situ biomass and exopolysaccharides production involve a crucial advantage over other bioremediation alternatives such as lignocellulosic biomass-based materials. In this study, a biofilm-forming bacterium was isolated from an ambient exposed to heavy metals. Bacterial biomass was inoculated on a biofilter packed with Furcraea andina fibers. The goal was to develop a continuous low-cost biofilter to remove low-to-moderate concentrations of Pb²⁺. Adsorption equilibrium and kinetics were determined for the fibers and the biofilm developed on the fibers. Biofilm presence had positive effects on the maximum adsorption capacity and the process kinetics. Biofilters packed with 20 g of F. andina fibers, with and without living biomass biofilm, were evaluated under continuous inflow of Pb²⁺ (325 mg/day) at a concentration of 50 mg/L. The best results were obtained with the biofilm-fiber biofilter where total adsorption on Pb²⁺ were observed for 72 h. Maximum absorption capacity was 48.75 mg/g at pH = 7.