Verfahren zur Abwasser-Aufbereitung in der Speisefett- und Fett-verarbeitenden Industrie

Processing of Waste Water in Edible Fat and Fat-Processing Industry Fat-containing waste waters belong to the category of moderately difficult to degrade waste waters, depending on the concentration and quality of the fat, either emulsified or unemulsified. Of great importance is an optimum mechanical clarification, which may be carried out in several steps depending upon the composition of the water. These processing steps involve sieving for the coarse separation, use of fat separator, and/or floatation. The process of floatation accomplishes a highly effective clarification if, in a prior stage, the waste water is treated with electrolytes to break the emulsion. The operation of floatation plants requires careful consideration of specific criteria. Waste water, after preliminary clarification, is generally subjected to biological purification. Various processes can be applied, depending on the type of waste water. Thus, trickling filters, especially those filled with plastics, can be of advantage, yet, due to their effectivity and simplicity activated sludge processes are popular. Characteristic features of activated sludge processes are discussed and a process for optimization of biological degradation is described. An integral part of the biological plant is the final clarification. The important parameters for operation and layout of final clarification units are given. Treatment of the sludge is gaining importance. Sludge and sludge residues having good utility are obtained from previously clarified waste waters described here. Suitable use of the excess sludge should be attempted.