Treatment of Vegetable Wash Water
Extremely strict hygiene regulations are applied during the processing of vegetables into convenience products on the one hand, large quantities of organic substances are also obtained when the vegetables are cleaned on the other hand; this waste can rapidly start to rot. This makes it doubly necessary to devote a great deal of care to treating the wash water. Centrifugal separation technology from GEA Westfalia Separator is ideal for these applications as a result of their closed design and their high dewatering capacity.
Wash water purification in vegetable processing
At the beginning there is an extensive full bath for the vegetables that have just been harvested and which are still contaminated with various foreign substances, such as humus, insects, worms and other undesirable impurities. The packaged products should after all contain only what is on the label. The high content of organic substances in the wash water means that extensive treatment is essential because it cannot be discharged into the sewerage system or the environment in this condition. Mechanical separation of the solids is a simple and cost-effective method of cleaning the wash water. This reduces the costs of fresh water as well as storing and disposing of the residues.
A rake is the first cleaning stage in which coarse solids such as vegetable leaves are separated and transported for further use, e.g. as animal feed. The pre-cleaned wash water is then rid of dirt and sand in a sand trap; the water is further purified in a bowl strainer machine and discharged into a settling tank.
The wash water that has been treated in this way is now pumped into the decanter. Any fine substances still contained in the wash water are now continuously separated and discharged with a high dry substance content. The separated solids can be processed into animal feed, and the water that has been clarified by the decanter is discharged into a retainer tank and then to the waste water treatment plant.