Aerobic Reactor Wastewater Treatment Fluidized Aerobic Bioreactor

Aerobic Reactor Introduction:

An aerobic reactor exploits oxygen as the terminal electron acceptor and is able to sustain a large number of important reactions that use a number of different electron donors. Principal among these are: oxidation of organic material, which reduces the BOD; oxidation of ammonia to nitrate, which reduces the ammonia concentration; and the luxury uptake of phosphate with the synthesis of polyphosphate, which reduces effluent phosphate concentrations.

A variety of options are available to achieve aerobic conditions in wastewaters. The strength of the incoming wastewater dictates the amount of oxygen that must be introduced into the reactor and guideline values are around 1.2 mg oxygen for every mg of BOD to be removed and 4.8 mg of oxygen for every mg ammonia to be removed. Thus, for a wastewater which has a BOD of 180 mg/l and ammonia of 25 mg/l and which must achieve an effluent quality of 20 mg/l BOD and 1 mg/l ammonia, it is necessary to introduce 307 mg O2/l. Natural processes such as atmospheric diffusion and photosynthesis are able to introduce oxygen to a wastewater, although very slowly and thus the wastewater must be retained for a long time to achieve the necessary oxygen transfer. As a consequence, natural treatment options, such as waste stabilization ponds, have long hydraulic retention times, typically between 15 and 40 days, with large reactor volumes. By contrast as the rate of oxygen transfer is increased by mechanical means, the retention time of the wastewater can be reduced to as little as a few hours in the activated sludge process. However, as aeration intensity increases, so does the cost of the treatment process and high intensity aeration is both capital and operating cost intensive.

Aerobic Reactor Specification: