Improved biological waste water purification reactor and method

摘要

A biological purification reactor and process, wherein the water to be treated and oxygenated gas are sent in ascending co-currents in the same reactor comprising as a biological filtering material a packed bed and a volume of movable, hollow carriers having a protected surface area for growth of the microbial film. The purifying reactor 1 comprises a space for expansion and removal of sludge 2, a gas injection system 4, a fluid injection system 3, a biological filter comprising a packed bed 5 of particles retained in a lower part of said reactor by a perforated retention ceiling 6 against upward movement, and a volume of movable particles 10 located within the said space for expansion and removal of sludge 2. The movable particles have a higher density than the packed bed particles. The purifying method further comprises periodical back washing steps.