Robust and economical, biological treatment has attracted large interest as a process for treating wastewater and waste gases. A substantial amount of research efforts have been devoted to this topic in recent years since bioreactors offer a cost-effective and environmental friendly alternative to conventional control technologies. In addition, resource recovery has recently become a must for consolidating environmental technologies in the market. We aim at the removal of SO2 contained in combustion of gases as well as sulfate-rich waste waters by means of a combination of biological reactors enriched with thermotolerant enzymes that allow recovering elemental sulfur, a marketable product, with large efficiencies.