MY PERSONAL VIEW OF SEQUENCING BATCH REACTORS

(PICTURE TAKEN FROM WWW.BIOUROCLEAN.IE)

When we talk about aerobic biological wastewater treatment, we are always confronted by various types of bioreactors that are available to treat the wastewaters. Though each of the bioreactor might have different design, geometry or configuration, all have the same fundamental process as follows:

Wastewaters ( Food)---> [Microorganisms in bioreactor]------> Treated wastewaters + Increase biomass



In aerobic biological wastewater treatment we cannot run away from the microbiology and biochemistry of the process. Every aerobic biological wastewater treatment package which we choose have its negative and positive characteristics

In the case of the sequencing batch reactor, it is more the modification or adaptation of the activated sludge system. As it is now we are already having variants of the activated sludge systems from extended aeration even to the Hatfield process. There is nothing new.

The only good point mentioned in SBC are that it requires less foot print and if operated properly as a batch reactor it should theoretically gives a more complete treatment or oxidation of the wastewaters.

The weakest link in any SBC or any biological wastewater treatment is poor understanding of the various biological processes operating in the reactors. We cannot regard microbes in wastewater treatment to be working in the ideal state and as part of well controlled engineering ' particles'

In the case of SBC it looks too over simplistic as everything is regulated by timing..time to fill, time to be anoxic, time to be aerobic, time to settle and decant and even time to rest :)).
I have always wondered if there is enough time for the microbes to grow, adapt and respond to the ever changing composition of the wastewaters?

It is of no wonder that most wastewater treatment plants do not work as most are so concerned with the engineering and theoretical aspects of operations and calculations but poorly understanding and controlling the process?

Is biological wastewater treatment an exercise in stochastic process?