Method for reducing the odour emission of water streams arising in the food industry

摘要

The invention relates to a method for reducing the odour emission at the direct cooling of elevated-temperature water streams occurring in the food industry, for instance at the direct cooling (7) of steam (6) arising in sugar production, which comes from the evaporating pans (1) and has a temperature of approximately 55 DEG C. Such water streams are exposed at a temperature in the range of 40-60 DEG C and in a closed reactor (10) without aeration to the action of aerobic thermophilic microorganisms which are capable of reducing the odour emission. Advantageously, the water stream is passed over solid supports such as Pall rings and the like with thermophilic microorganisms immobilized thereon. Preferably, 0.7-2m<2> of film of thermophilic microorganisms per m<3>/h condenser water is used. Examples of thermophilic microorganisms are Sphaerotilus natans, Haliscomenobacter hydrossis, Flavobacterium sp, Thiothrix sp and/or Beggiatoa sp. It is found that the reduction in odour emission may amount to a factor of 6. $$