PROCESS AND REVERSE FLUIDISED LOOP REACTOR FOR WASTEWATER PURIFICATION

摘要

The present invention relates to a process and an appartus for the biological treatment of wastewater which involves the conversion of some of its inorganic constituents, particularly sulphide, iron or manganese into solid products and surplus sludge. The process is catalysed by selected microorganisms which are fixed on floating carrier-particles. A suitable biofilm reactor comprises a vertically elongated reaction vessel (1), provided with one or more inlets (2) for feeding wastewater, outlets for drawing off the treated wastewater (12) and a draft tube (7) into which gas, preferably air is injected to create a circular flow of the carrier particles which thereby form a reverse flow fluidised bed (9). Part of the gas is re-used by means of a pump (14). The floating carrier-particles are separated from the product in the disengagement zone (11) and settling zone (8), with the product being collected in the conical shaped reactor-bottom (10), from where it is removed by the nozzle (5). Setting of the product particles in the lower part of the reactor (8) is facilitated by baffles (13).