Thermal Treatment of Industrial Waste Water
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Thermal Treatment of Industrial Waste Water Process Engineering / GEA Wiegand GmbH

Technologies, Research and Development 3 Wastewater Containing Oil and Salts, from Waste Disposal Companies and Tank and Barrel Cleaning 5 Waste Water from Industrial Laundries 6 Toxic Waste Water from Chemical Production Processes 7 Waste Water from the Production of Wood Fibre Boards (MDF) 8 Waste Water from Wood Steaming 9 Waste Water from Biotechnology 10 Organic Waste Water from the Food and Starch Industry 12 Waste Water from Olive Oil Production 14 Fermentation Residuals from the Bio-gas Production 15 Thermal Treatment of Industrial Waste Water There are many industrial uses for...

Laboratory in the GEA Wiegand Research and Development Centre Technologies Thermal separation of substances is particularly suited if the waste water cannot be clearly defined, and if its ingredients, dry substance contents, pH value or particle size changes frequently and if it should be highly concentrated. When designing evaporation and distillation plants, numerous requirements must be taken into consideration, for example product-specific substance values, energy conditions and the overall local situation. The selection of the type of construction and arrangement is based on these...

Oil-Water Emulsions In the metal-working industry, oil-water emulsions are used as a cooling agent and as a lubricant. After an expensive regeneration they are re-used several times, but after a certain period they have to be renewed. It is the objective of the treatment to separate the oily substances from the watery portions. The contamination of the water should be as low as possible prior to it being discharged to a sewage treatment plant, or prior to being re-used in the factory; the oily content should be highly concentrated and transferred, for example, to an incineration plant....

Waste Water Containing Oil and Salts, from Disposal Companies and from Tank and Barrel Cleaning Waste water occurring in disposal companies have several origins and strongly vary regarding quantity and composition. Even with an appropriate pre-cleaning it is rarely possible to achieve a uniform waste water composition. The situation in barrel and vessel cleaning companies is similar. Rinsing and cleaning water produce euents with continuously changing quantities of salts, oils, tensides, sludges, organic substances and heavy metals. A treatment system for such difficult waste waters must be...

Waste Water from Industrial Laundries In many industrial areas, cleaning cloths are used to absorb greasy, oily or other fluid residuals. Apart from throw-way cleaning cloths, mainly cleaning cloths are used which can be washed and re-used. In special washing machines tensides and cleaning agents are added to wash out the dirt. A washing water remains which is highly loaded, perhaps even with different solid matter portions of chips, abrasion particles and colour pigments. It is the objective of the water treatment to clean the water as much as possible so that it can be re-used for the...

Toxic Waste Water from Chemical Production Processes In the production of plant pesticides, such as herbicides and fungicides, but also in other chemical processes waste water is produced which essentially consist of several organic components, and a considerable amount of salt and mainly of water. The treatment of these waste waters is very difficult because their toxicity hinders dumping. Disposal has to be achieved in an incineration plant. As the concentration of the ingredients in the waste water is relatively low, for cost reasons a concentration prior to incineration is...

Waste Water from the Production of Wood Fibre Boards (MDF) As raw material for the wood fibre board production, mainly round wood, chipped wood, slabs and saw dust is used. In the process of fibre board production, large quantities of organically loaded waste water occur. Depending on the process, they are strongly contaminated by wood ingredients, such as organic acids, saccharides, aldehydes and terpenes. With evaporation, an economical treatment of these waste waters is possible. pressure steam in steam converters or before they can be discharged to the waste water system. The...

Waste Water from Wood Steaming In the wood-working industry, round and timber wood is steamed before and after the paring and sawing process. The steaming results in a modification and stabilization of the wood quality. During the steaming process, large quantities of slightly acidic condensate accumulate, a waste water which mainly contains organic acids and water-soluble wood polyoses. This condensate must be collected and disposed or treated. For these applications, an evaporation has important advantages. The evaporated water (vapour) can be directly used for steaming, the concentrated...

Waste Water from Biotechnology In large-scale biotechnological production processes, large quantities of waste water are produced. Depending on the process they are strongly contaminated and can neither be re-used without a prior treatment nor can they be introduced into the sewage system. Due to the strong contamination by organic substances and salts, in most of the cases a biological treatment is not efficient, or is too complex. The contents of these waste water, however, are best suited for the production of fertilizers and fodder. For this purpose, the waste water is concentrated in...

Figure (right): Two-effect falling film forced circulation evaporation plant with two mechanical vapour recompressors to concentrate waste water from lysine production. Evaporation rate 67,500 kg/h Figure (centre): Layout of two five-effect falling film forced circulation evaporation plants for the concentration of waste water from monosodium glutamate production. Evaporation rate: 2 x 120,000 kg/h Sketch (below): Five-effect falling film forced circulation evaporation plant, directly heated Heating steam 1 5 2 1 5 2 1 1 4 5 1, 2 Falling film evaporator 3, 4 Forced circulation evaporator 5...