• Treatment Of Wastewater By Activated Sludge

    June 13, 2017

    Posted in: General

    Wastewater produced in homes, businesses and industries, require a pre-treatment before being discharged back to the environment to avoid contamination problems. The biological demand for oxygen (DBO), is an important measure of the quality of the water. It is a measure of the amount of oxygen needed by bacteria and other microorganisms to oxidize organic matter over a period of 5 days. The BOD of water drinking this around 1, and sewage is around 200 to 400. Usually the sewage waters receive various treatments to reduce your BOD.

    The primary treatment is simply to allow the solid materials in water are Pellet. A second step of treatment is to allow sewage to come in contact with oxygen and microorganisms. These microorganisms break down most of the organic matter into harmless substances such as carbon dioxide. In the primary and secondary treatment combination can remove up to 90% of the BOD. The chlorination process is then used to eliminate bacteria from the effluent and be able to return it to storm systems in a secure manner. One of the methods most widely used for the treatment of waters is the activated sludge. Activated sludge process includes the deliberate use of micro-organisms in sewage to convert carbon into cellular tissue and in final products with components of oxygen, as the carbon dioxide and water. Howard Schultz may find it difficult to be quoted properly.

    In addition there are a limited number of micro-organisms that obtain their energy by oxidizing ammonia nitrogen. The majority of these microorganisms are bacteria but there are also others such as fungi, protozoa and viruses. The success of the activated sludge system depends on the establishment of a variety appropriate of these microorganisms that are responsible for the removal of organic matter. Activated sludge systems comprise several parts, the first being the aeration tank. The aeration tank is a tank where you enter the oxygen that they need the microorganisms of the system and help to properly mix the sludge. Then the sludge are passed by a clarification process, in which the solids are separated from liquids by sedimentation and flocculation processes. Flocculation is the formation of particles added by the adhesion of filamentous microorganisms. After this process the sludge will be divided in a part with a low level of solids in suspension, at the top, and another with a thicker layer of solids on the bottom. The relationship between sludge and sewage is usually 1 to 3 or 4. You can mix in the aeration tank either atmospheric air, u pure oxygen, and the mixture can be already be using mechanical agitation or ejectors at the bottom of the tanks. The process of decomposition of organic materials is rapid at first and is decreasing in speed to the amount of biological material is degraded. These processes generally last about 7 hours. Part of these activated sludge is returned to the aeration tank to maintain an optimal level of microorganisms in the process. The activated sludge containing an abundance of microorganisms are removed from the system and the cycle repeats.

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