This chapter presents results from investigations carried out by our research consortium within an EC-funded project to accomplish effective in situ treatment of food industry wastes under thermophilic aerobic conditions and achieve safer, cleaner, more energy-efficient bioremediation of European food wastes (cheese whey, grain stillage, potato slops/stillage). We found that Cocurrent Downflow Contactor technology, with its enhanced oxygen mass transfer capacity, could be used successfully to carry out thermophilic, aerobic biotreatment of cheese whey, especially under conditions of high oxygen demand, where biomass recycling was used in a high-rate process.