removal among the reactors (influent oil: 250 mg/L). However, longest HRT (12 h)
had maximum contact time between granules and pollutants which helped in 90% oil
removal. Gas chromatogrphy results predicted degradation of some short and long
chain n-alkanes (C 6 -C 27 ) which followed a pathway of conversion into fatty acids
which further undergo ß-oxidation. Nitrogen balancing data suggested that
about 2–20% complete nitrification occured inside the aerobic granules. About
24–77 mg/L of efflent oil concentration was recommended to avoid phytotoxic
effects after wastewater disposal.
Detailed description of aerobic granular reactor operating conditions, granule
characteristics and pollutant removal efficiencies in different types of hydrocarbon-rich wastewater treatment are elaborated in Table 6.2.
6.7 Conclusion
Aerobic granulation technology has been successfully employed in treating both real
and synthetic hydrocarbon-rich wastewater. Aerobic granulation provided a very
stable and cost-effective treatment process which was able to withstand high organic
loads, fluctuation in toxic chemical concentration and finally produced effluents with
lower pollutant concentration than the conventional wastewater treatment processes.
Microbial diversity in aerobic granules helped to simultaneously degrade carbon,
nitrogen and different types of recalcitrant aromatic hydrocarbons.
According to literature, aerobic granulation was able to treat oily wastewater
containing hydrocarbons between 5.6 to 320 mg/L. However, everyday oil refineries
produce real petrochemical wastewater in million litres volume containing higher oil
concentration than the previous reports. Biological treatment and effluent management of large volume of complex oily wastewater is still a big challenge. However
some research areas are still unexplored; like literature reporting complete nitrification in petrochemical wastewater treatment are limited, treatability of automobile
effluents and heavy motor oil by using aerobic granular sludge is not studied so far,
whether bioaugmentation of oil degrading pure strains can improve granule oil
removal efficiencies is still unknown, effects on hydrocarbon removal by changing
superficial air velocity and feed up-flow velocity of an aerobic granular reactor are
not well accounted, potentiality of renewable biomaterial production using oil
treated waste granules is also not well explored so far. Hence, these knowledge
gaps would reveal new domains of research in aerobic granulation treating hydrocarbon-rich wastewater treatment.
Acknowledgement Authors thankfully acknowledge Centre for the Environment, Indian Institute
of Technology, Guwahati, for providing the analytical laboratory and instrumentation facility to
conduct the literature survey and research. We are grateful to Dr. Inamuddin for his kind cooperation throughout the book publishing process.
6 Aerobic Granulation in Hydrocarbon-Rich Wastewater Treatment
187
had maximum contact time between granules and pollutants which helped in 90% oil
removal. Gas chromatogrphy results predicted degradation of some short and long
chain n-alkanes (C 6 -C 27 ) which followed a pathway of conversion into fatty acids
which further undergo ß-oxidation. Nitrogen balancing data suggested that
about 2–20% complete nitrification occured inside the aerobic granules. About
24–77 mg/L of efflent oil concentration was recommended to avoid phytotoxic
effects after wastewater disposal.
Detailed description of aerobic granular reactor operating conditions, granule
characteristics and pollutant removal efficiencies in different types of hydrocarbon-rich wastewater treatment are elaborated in Table 6.2.
6.7 Conclusion
Aerobic granulation technology has been successfully employed in treating both real
and synthetic hydrocarbon-rich wastewater. Aerobic granulation provided a very
stable and cost-effective treatment process which was able to withstand high organic
loads, fluctuation in toxic chemical concentration and finally produced effluents with
lower pollutant concentration than the conventional wastewater treatment processes.
Microbial diversity in aerobic granules helped to simultaneously degrade carbon,
nitrogen and different types of recalcitrant aromatic hydrocarbons.
According to literature, aerobic granulation was able to treat oily wastewater
containing hydrocarbons between 5.6 to 320 mg/L. However, everyday oil refineries
produce real petrochemical wastewater in million litres volume containing higher oil
concentration than the previous reports. Biological treatment and effluent management of large volume of complex oily wastewater is still a big challenge. However
some research areas are still unexplored; like literature reporting complete nitrification in petrochemical wastewater treatment are limited, treatability of automobile
effluents and heavy motor oil by using aerobic granular sludge is not studied so far,
whether bioaugmentation of oil degrading pure strains can improve granule oil
removal efficiencies is still unknown, effects on hydrocarbon removal by changing
superficial air velocity and feed up-flow velocity of an aerobic granular reactor are
not well accounted, potentiality of renewable biomaterial production using oil
treated waste granules is also not well explored so far. Hence, these knowledge
gaps would reveal new domains of research in aerobic granulation treating hydrocarbon-rich wastewater treatment.
Acknowledgement Authors thankfully acknowledge Centre for the Environment, Indian Institute
of Technology, Guwahati, for providing the analytical laboratory and instrumentation facility to
conduct the literature survey and research. We are grateful to Dr. Inamuddin for his kind cooperation throughout the book publishing process.
6 Aerobic Granulation in Hydrocarbon-Rich Wastewater Treatment
187