Platinum group metal (PGM) miners and recycling facilities are losing ~$2 billion (~10% of the total market value) of PGM annually in wastewater and tailing. The membrane biofilm reactor (MBfR) is a modular biotechnology which contains a microbial community that can reduce and recover PGM at mining, refining, or manufacturing sites at concentrations between 0.04 and ~500 ppm. The biofilm employed in the MBfR naturally accumulates PGM, including elemental palladium (Pd0), as nanoparticles that have high economic value due to their high specific surface area and superior catalytic capability. In contrast, conventional physical and chemical processes for PGM recovery are costly, often inefficient, and introduce contamination into the environment. Thus, MBfR technology is a relatively low-cost and benign alternative to conventional PGM recovery techniques.