SU0003122 - Laserfiche WebLink

Home Browse Search

The tank inlet and outlet are level and partially baffled, causing retention of a portion of the solids. This retention allows the micro- NOTES organisms to develop large colonies. This simple collection of solids reduces the overall loading to the aeration reactor and hastens the process of converting organic nitrogen to ammonium ions. It also supplies soluble BOD as effluent product/influent wastewater to the aeration tank. The lowering of BOD levels in the aeration reactor forces depletion of available BOD food source in the extended aeration phase. This enhances the natural dominance of nitrosomonas and nitrobacter organisms. These organisms predominate and utilize the dead cells as a carbon source, converting ammonium nitrogen (NH,), as a nutrient base,to nitrite (NO) through oxidation. A portion of the resulting nitrate (NO,) rises to the surface of the reactor and is reduced prior to reaching atmosphere. The nitrosomonas are responsible for conversion of ammonium ni- trogen to nitrite, which sponsors the rapid nitrobacter conversion to nitrate: NH, + 3/202 —2H + H2O + NO2 (1) and a portion of the NO2 is then oxidized to NO,: NO2 + 1/2 02 — NO3 (2) THE AOUACLEAR PROCESS, DESIGN, AND DESCRIPTION The AquaClear process concept is derived in part from federal regu- latory agency guidelines as detailed in Recommended Design Crite- ria for Activated Sludge Processes. Raw sewage/wastewater enters the aeration tank, where previously developed biological floc particles are brought into contact with the incoming, suspended organic matter. The organic matter is a carbon and energy source for cell growth and is converted into cell tissue and oxidized end products(mainly carbon dioxide, CO). The content of the aeration tank is called mixed liquor (ML). The biological mass is referred to as the mixed-liquor suspended solids (MLSS), or mixed-liquor volatile suspended solids (MLVSS), and consists mainly of microorganisms, inert suspended matter, and non- biodegradable suspended matter. After a preset time period, the mixed liquor is transferred to the clarifier tank for separation of suspended solids from the treated wastewater. The biological solids are then returned to the aeration tank to maintain a concentrated population of microorganisms to treat new, incoming waste. The use of microprocessor and computer technology has allowed modifications of the timing cycle which controls the amount of time 11