10
2 Advantages of Hybrid Bioreactor
2.1.2 Surge Loading
Sudden increase in the organic load of influent wastewater causes a shock to the
microorganisms, which are exposed to a certain organic concentration in the aeration
unit. In that case, inhibition may also take place due to additional substrate (organic
matter) leading to process failure.
2.1.3 Inability to Maintain Uniform Biomass Concentration
The suspended biomass in the aeration tank is subjected to wash out when there is
no recirculation of biomass. This problem is most acute for low-strength wastewater.
At the same time, concentration of the settled sludge in secondary clarifier varies
and therefore the rate of biomass recirculation also needs to be adjusted. However,
continual adjustment is not always feasible, causing a fluctuation in the biomass
concentration of the aeration tank.
2.1.4 Poor Settleability in Secondary Clarifier
There is a limitation on clarifier solids loading that put an upper limit on the amount
of biomass in the suspended-growth system. If MLSS content is too high, especially
greater than 3500 mg/l the sludge matrix becomes tight and poorly settles in the
secondary clarifier. As a result, the quality of effluent also deteriorates due to improper
solid–liquid separation. This can also cause the dissolved oxygen (DO) content to
drop, which affects the aerobic degradation of organic matters. Two principal types
of enhanced biomass, i.e., sludge bulking problems like filamentous bulking and
viscous bulking are observed in ASP process. Filamentous bulking is due to the
growth of filamentous organisms, whereas viscous bulking is on account of the
excessive amount of extracellular polymers producing the sludge with a slimy, jellylike consistency [1].
2.1.5 Inadequacy to Withstand Toxic and Inhibitory
Substances
Slowly biodegradable substances in the wastewater are generally the aliphatic and
aromatic organic compounds (e.g., Phenol, Benzene, Toluene, Xnylene, Chloroform, etc.), and their salts with sulfate, chloride, etc. which pose unique problems
in wastewater treatment, due to their resistance to biodegradation and potential toxicity to the environment and human health. These compounds are difficult to treat in
2 Advantages of Hybrid Bioreactor
2.1.2 Surge Loading
Sudden increase in the organic load of influent wastewater causes a shock to the
microorganisms, which are exposed to a certain organic concentration in the aeration
unit. In that case, inhibition may also take place due to additional substrate (organic
matter) leading to process failure.
2.1.3 Inability to Maintain Uniform Biomass Concentration
The suspended biomass in the aeration tank is subjected to wash out when there is
no recirculation of biomass. This problem is most acute for low-strength wastewater.
At the same time, concentration of the settled sludge in secondary clarifier varies
and therefore the rate of biomass recirculation also needs to be adjusted. However,
continual adjustment is not always feasible, causing a fluctuation in the biomass
concentration of the aeration tank.
2.1.4 Poor Settleability in Secondary Clarifier
There is a limitation on clarifier solids loading that put an upper limit on the amount
of biomass in the suspended-growth system. If MLSS content is too high, especially
greater than 3500 mg/l the sludge matrix becomes tight and poorly settles in the
secondary clarifier. As a result, the quality of effluent also deteriorates due to improper
solid–liquid separation. This can also cause the dissolved oxygen (DO) content to
drop, which affects the aerobic degradation of organic matters. Two principal types
of enhanced biomass, i.e., sludge bulking problems like filamentous bulking and
viscous bulking are observed in ASP process. Filamentous bulking is due to the
growth of filamentous organisms, whereas viscous bulking is on account of the
excessive amount of extracellular polymers producing the sludge with a slimy, jellylike consistency [1].
2.1.5 Inadequacy to Withstand Toxic and Inhibitory
Substances
Slowly biodegradable substances in the wastewater are generally the aliphatic and
aromatic organic compounds (e.g., Phenol, Benzene, Toluene, Xnylene, Chloroform, etc.), and their salts with sulfate, chloride, etc. which pose unique problems
in wastewater treatment, due to their resistance to biodegradation and potential toxicity to the environment and human health. These compounds are difficult to treat in