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Technical Description <br /> LM <br /> 1. A static fine screen is mounted outside the aeration chamber. As the raw waste stream flows <br /> across the metal grating, foreign articles are captured and fall into a dropbox. Sewage waste <br /> passes through the screen directly into the aeration chamber. <br /> 2. A comminutor,mounted outside the aeration chamber,reduces the size of all incoming matter <br /> �., by high-speed cutting. After passing through the comminutor, waste enters the aeration <br /> chamber. <br /> �. PHYSICAL PRETREATMENT <br /> SEPARATION AND NITRIFICATION INITIATION. (NOTE. The following may not be required for <br /> nitrification where detention periods of 14 hours or more are anticipated. With reduced solids <br /> concentration, the normal calculated aeration demand for the batch process is sufficient for <br /> nitrification supplementation. Should external nitrification be deemed necessary, the following <br /> procedure is used.) <br /> Prior to entering the treatment plant,raw sewage may be collected in a baffled buffer tank.The buffer <br /> tank is anaerobic and sized for a detention period which will allow solid/liquid separation, retention <br /> ` of solids and floatable materials, and promotion of facultative anaerobes by degeneration of natural <br /> dissolved oxygen levels. <br /> �- The tank inlet and outlet are level and partially baffled, causing retention of a portion of the solids. <br /> This retention allows the microorganisms to develop large colonies. This simple collection of solids <br /> reduces overall loading to the aeration reactor and hastens the process of converting organic nitrogen <br /> '~ to ammonium ions. It also supplies soluble BOD as effluent product/influent wastewater to the <br /> aeration tank. <br /> r. The lowering ofBOD levels in the aeration reactor forces depletion of available BOD food source in <br /> the extended aeration phase. This enhances the natural dominance of nitrosomonas and nitrobacter <br /> organisms. These organisms predominate and utilize the dead cells as a carbon source, converting <br /> %W ammonium nitrogen (NH), as a nutrient base, to nitrite (NO) through oxidation. <br /> A portion of the resulting nitrate (NO ) rises to the surface of the reactor and is reduced prior to <br /> reaching atmosphere. <br /> The nitrosomonas are responsible for conversion of ammonium nitrogen to nitrite,which sponsors the <br /> rapid nitrobacter conversion to nitrate: <br /> NW,+ 3/2 OZ —* 2W+H2O +NO2 (1) <br /> and a portion of the NO2 is then oxidized to NO3: <br /> NO2 + 112 02 --> NO- (2) <br /> W <br /> The use of microprocessor and computer technology allows modifications of the timing cycle which <br /> controls the amount oftime the sludge spends in the treatment system.It is this cycle which is referred <br /> 9 <br />