Aufbereitung industrieller Abwässer

Processing of Industrial Waste Water Government regulations concerned with environmental safety are getting increasingly rigid; the law governing the chanelling of industrial waste water will come into force in 1981. Consequently, the responsible persons, even in medium and small industrial units, are compelled, either to take necessary steps towards minimizing the consumption of fresh water and processing the waste water within the factory, or to pay heavy charges to the responsible organization. In this contribution, ways and means are shown, which should enable the industrial undertakings to take the necessary steps toward improvement of water treatment with due consideration of the economical aspects of an industrial concern. As an example, production unit of the food industry is described in order to show the technical possibilities for processing waste water.     

Die Flotation — ein geeignetes Verfahren zur Aufbereitung öl- und fetthaltiger Abwässer

Flotation — a Useful Procedure for Treatment of Oil and Fat Containing Waste Water Waste water of the oil and fat manufacturing industry is characterized by a high content of by petrolether extractable compounds (fats and oils), protein and similar compounds. A considerable part of the contained oil is submitted in emulsified form and cannot be removed by mechanical treatment (gravity separator). Therefore an extensive precleaning is necessary before emission into an outfall ditch, passing in circuit of single streams or introducing into a biological cleaning stage. For this purpose physical/chemical processes are used, whereat in connection with a flocculation chamber the sedimentation — but preferred the flotation — comes into question. Different technical designs and constructive measures which are to con sider for optimal cleaning efficiency are described. Proposals for the design of plants are given too.     

Dampfstrahl-Vakuumpumpen in der Öl- und Fettindustrie Energieverbrauch und Abwassertechnik

Steam Ejectors in Oil and Fat Industry: Energy Consumption and Waste Water Technology Steam ejectors convey gases and vapours from distillation and deodorization columns via intermediate condensers to atmospheric pressure. Inspite of utmost care taken for the separation of liquid or solid particles at the point of suction, some of these particles are carried over into the vacuum lines and are deposited at the cold surfaces of the vacuum system. Measures to prevent this carry over by scrubbing, freezing or heating need additional energy. Minimizing such energy requirements is one of the tasks of the processing engineer, plant manufacturer and plant operator. In the presented work, the influences of suction pressure, intermediate pressure, boosting steam pressure, cooling water temperature and temperature of the surroundings were correlated. Different possibilities of connection are shown, which can be chosen depending upon local requirements in order to minimize environmental pollution.     

Einsatz von Beutelfiltern in der Speiseöl- und Margarineproduktion

Use of Filter Sacks in Edible Oil and Margarine Production Filter sacks, made out of felt, are used in various steps of production of margarine and edible oil, such as clarification of miscella, post deodorization (before or after the cooler), and polishing filtration before blending and packaging. This filter sack system offers excellent economy and simple operation. The rapid change of filter sacks, compact size of the pressure filter, and high flow rates at long periods of use are illustrated with practical examples of application.     

Biologische Denitrifikation nitrathaltiger Abwässer und Grundwässer

Biological denitrification of nitrate-containing waste water and ground water. The differing objectives serve to distinguish processes for the treatment of waste water and those for the production of drinking water. In waste water purification, frequent use is made of submerged reactors with deposition and recycling of bacteria. The carbon compounds required by the bacteria are either present in the water or have to be added. If the nitrogen is present as ammonium in the waste water, then there are several different ways of combining nitrification and denitrification reactors. In production of drinking water, both heterotrophic and autotrophic bacteria are used. Since the bacteria are not allowed to enter the supply network, fixed reactors or other reactors with immobilised biomass are used. Sand bed filters are still necessary to retain compounds from the water after denitrification.     

Objektive Bewertungskriterien bei der Beschaffung,Planung und Erstellung von Anlagen für die Öl- und Fettindustrie

Criteria of Assessment for Purchase, Design and Installation of Plants and Equipment in the Oil- and Fat-Industry Purchase of plants and plant-equipment requires mutual issue and disposal of characteristic data between tenderer, seller and purchaser. In normal practice, factual information ranges between a single letter of five lines and a tender of several hundred pages. Substantial and well defined criteria as essentials on part of the offering engineers and the comparability of offers on part of the tenderers, in fact are a problem of common mutual availability Deficiencies of this kind only are avoidable when either part has sufficient data in a well collected general account at their disposal. The authors are working out a catalogue of criteria comprising all relevant procedures of procurement and planning, together with computer-aided assessment facilities.     

Aufarbeitung Ammoniak enthaltender Abwässer – Verfahrens- und Kostenvergleich

Purification of waste water containing ammonia – Comparison of proces and costs. The present case study compares three processes for reduction of ammonia in liquid effluents with respect to process engineering and treatment costs: stripping with steam, stripping with air, and liquid membrane technology. The specific purification costs are estimated for plant capacities between 1 and 50 m³/h, for NH₃ feed concentrations between 50 and 2000 ppm, and for waste water feed temperatures between 5 and 80ßC. Moreover, the NH₃ exiting concentration is varied between 1 and 500 ppm. In the standard case, the estimates are based on a decrease to 5 or 50 ppm NH₃ in the waste water. Two cases are considered: in one, it is assumed that the ammonium sulphate solution produced by all three processes must be evaporated down to a disposable form. Alternatively, it is assumed that the ammonium sulphate can be used without further work-up.     

Dampfstrahl-Vakuumpumpen in der Speiseöl-Industrie Auslegungsmerkmale und Betriebserfahrungen

Steam Jet Vacuum Pumps in the Edible Fat Industry - Lay-out Features and Performance in the Practice As a supplement to a previous contribution, the influences of the selected working pressure, the pressure drop in the pipes, and the pressure of the condenser on the operating costs are discussed in details.