Industrial sewage sludge
Processing of natural raw materials and feedstock to food or daily goods frequently uses huge amounts of water.
Before canned vegetables arrive on your desk it will be cleaned, peeled, blanched or cooked. The result of this process also is a lot of highly contaminated effluent. When wood is solubilized to pulp, paper, cellulose, textile fibre etc. highly contaminated water with dissolved side components of wood will appear.
Before a beef steak is on our dish, in slaughterhouses, at meat processing factories, processing stores for entrails, huge volumes of water are used. The side products from butcheries are processed to fat, oils, collagen and finally the skin is processed to leather in a tannery with highly polluted waste water.
Leaching of sugar beets or cane causes as much as effluent as the extraction of starch from corn, potatoes or crop.
From smaller processing factories the effluent is processed in a municipal Sewer Treatment Plant (STP), bigger processors run their own STP, which frequently have the same size as for a metropolis.
Microorganisms absorb the dissolved materials and they reproduce themselves by segmentation. In this way Surplus Activated Sludge (SAS) is created. Together with suspended solids from manufacturing process SAS forms the STP sludge. And this material must be incinerated in most cases.
To prevent the usage of much external, primary energy the sludge must be dewatered mechanically to the highest possible degree to keep the furnace running.
Many studies in (semi-)industrial scale showed the Bucher technology as the predominant benchmark.
The picture shows an installation in a considerable European Tannery.
If you are sitting on a convenient, skin friendly leather chair on a boat, in a car, in a train or airplane there is a high chance that a Bucher HPS has contributed to this feeling.