COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

Technical Description For sizing the air delivery system, the cubic-feet-of-air requirement is expressed as cubic feet of air required per pound of BOD removed from the aeration reactor. The minimum air/organic loading recommended by most state agencies is 1,000 cubic feet per pound of BUD. The Bio- Pure system expands this to 1,500 cubic feet per pound of BUD removed, allowing a residual air- base for compensation of higher organic loading than anticipated and to support further process- ing of ammonium nitrogen (NH4). Air availability is always maintained at 125% of maximum de- mand with the 25% residual over the 1,250 CF/000 gallons, bled off between the blower and the aeration tank. Because the total daily air requirement is dependent upon the pounds of BUD applied, the pounds of BUD entering the treatment plant must be known and can be calculated as follows: BxFxC=A where B = F = C = A = influent BOD5 mg/L system maximum daily hydraulic flow constant of 8.34 lbs of BOD5 entering daily DENITRIFICATION 02 ALLOCATION The conversion of ammonium to nitrate demands a support process to sustain the reaction. With oxygen being the only common acceptor, 02 demand/delivery is taken into the design considera- tion of the batch process. The energy produced by oxidation of NH4 and NO2 is used by nitrifying organisms primarily to produce new biomass. These bacterial cells can be represented by the approximate formula C511702N. The biomass synthesis reaction for nitrosomonas and nitrobacter is: NH4+HCO3 +4CO2 +H2U—> C511702N + 502 (3) This synthesis reaction requires an input of energy to proceed. During nitrification, this energy is obtained from NH4 and NO2 oxidation equations 1 and 2; therefore, reactions shown in equations 1 and 3 usually occur simultaneously. The energy yield from the oxidation of one mole of NH4 or NO2 is much less than the energy required to produce one mole of bacterial cells as (C5}1702N). Equations 1, 2, and 3 then must be proportioned so that after energy transfer efficiencies are taken into account, the energy used equals energy produced. The biological nitrification is then ex- pressed as: NH4 + 1.83 02 ± 1.98 HCO3 --> 0.021 C5H702N + 0.98 NO3 + 1.041 H2 0 + 1.88 H2CO3 (4) which can be used to estimate the three important parameters associated with the nitrification pro- cess: oxygen requirements, alkalinity consumption, and nitrifier biomass production. Nitrogen removal is accomplished in the Bio-Pure system without additional equipment or chemi- cals. Nitrogen enters the system in the raw wastewater in the form of organic nitrogen and ammo- nia (NH4). It is removed from the system in the form of nitrogen gas (N2). The actual process by which ammonia nitrogen is converted to nitrogen gas is a three-step process. First is nitrification, the conversion of ammonia nitrogen to nitrite (NO2). Second is the conversion of nitrite to nitrate (NO3). Third is denitrification, the conversion of nitrate nitrogen to nitrogen gas (N2). All of these