Membrane applications for microbial energy conversion: a review

Technologies for conversion of microbial energy have recently attracted interest to transform waste into bioenergy, thus addressing simultaneously environmental and energy issues. Nonetheless, actual microbial systems for energy conversion have limitations such as low rate of mass transfer, uneven energy distribution and strong inhibition of products and by-products. These technical bottlenecks can be alleviated by using membranes, which regulate the transfer of mass, heat and energy. Here we review applications of membranes for microbial energy conversion. We discuss mechanisms, functions and development of membranes for feedstock preparation, bioenergy production and bioproduct post-treatment. We present key membrane factors that control the efficiency of microbial fuel cells. We address membrane biofouling problems and anti-fouling approaches, in order to improve future commercialization.