from plant grains including olive oil and palm oil mills, butter, dairy, slaughter, and
detergent and soap manufacturing where fat or grease are used (Stams and Oude
1997). Greases often cannot dissolve and the emulsified fats efficiently enter the
waterremediation system. The oils, fats, and greases that are not treated can enter
oceans, seas, and rivers with harmful effects (Stams and Oude 1997). Heavy oil
causes physical blockages in pumps, screens, and filters. Light oils may accumulate
in the wet wells of pumping stations or floating systems. The major source of energy
and one of the most important initial materials for industries are crude
oilhydrocarbons that cause significant environmental threats and pollution (Varjani
and Upasani 2016; Arulazhagan et al. 2010). Pipelines accidents, vessels, land
runoff, offshore exploration, production operations, shipping activities, transport,
wide-scale production, coastal oil refining, and illegal bilge water discharges are the
main reasons for marine oil pollution (Lucas and MacGregor 2006). Repeated
accidental leak and illegal oil disposal impact on the sea ecosystems severely.
During the years 1970–2010, around 5.71 million tonnes of oil were entered to
seawater due to tanker incidents (Dave and Ghaly 2011). The oil spills have negative
effects on marine life, leisure activities, tourism, and aesthetic appeal. Some soluble
components of oil can enter the food chain via accumulating in the organs of animals
(Mackay and Fraser 2000). The average estimated cost to clean a crude oil spill is
$2730 per barrel (Dave and Ghaly 2011). Since the environmental fallout of cleanup
methods is inevitable, selecting the best methods is based on a trade-off between the
side effects of oil spill and the cleanup method. The type, quantity and characterization of oil spill, age of oil, impact of oil on marine life, environment situation, sea
behavior and weather conditions determine the most effective treatment technique
(Choi and Cloud 1992; Lessard and Demarco 2000; Buist et al. 1999). Several
methods including burning, use of dispersants, mechanical recovery, bioremediation, and use of solidifiers are applicable as response to an oil spill (Dave and Ghaly
2011; Ismail et al. 2019). In bioremediation, microorganisms degrade and metabolize chemical materials in order to restore the environment quality. The ubiquitous
microorganisms in the indigenous oil spill site degrade hydrocarbons in marine oil
spills. The specie of microorganisms introduced in the site depends on the process
design, environmental conditions, and the mode of plant operation (Amin et al.
2013). There is an ideal environment for many microorganisms in an activated
sludge system because of the agitation, constant aeration, and recirculation. Today,
the activated sludge system widely uses bioremediation processes for both domestic
and sewage wastewaters. The main microorganisms in wastewater are fungi, protozoa, bacteria, viruses, and nematodes. Reduction in the levels of oils, fats, and
greases in sewage is therefore very desirable and an appropriate potential candidate
for bioaugmentation. Biological augmentation includes the addition of archaea or
bacterial cultures in order to speed up the rate of degradation of the pollutants. Use of
bioaugmentation has other positive effects like increasing the efficiency and reduction of the toxic molecules (Brooksbank et al. 2007).
In this chapter, the source of oilcontaminants, the related prevention regulation
and bioremediation techniques, bioremediation mechanisms, its advantages and
disadvantages compared with other treatment methods and factors affecting
390
M. Fatehi et al.
detergent and soap manufacturing where fat or grease are used (Stams and Oude
1997). Greases often cannot dissolve and the emulsified fats efficiently enter the
waterremediation system. The oils, fats, and greases that are not treated can enter
oceans, seas, and rivers with harmful effects (Stams and Oude 1997). Heavy oil
causes physical blockages in pumps, screens, and filters. Light oils may accumulate
in the wet wells of pumping stations or floating systems. The major source of energy
and one of the most important initial materials for industries are crude
oilhydrocarbons that cause significant environmental threats and pollution (Varjani
and Upasani 2016; Arulazhagan et al. 2010). Pipelines accidents, vessels, land
runoff, offshore exploration, production operations, shipping activities, transport,
wide-scale production, coastal oil refining, and illegal bilge water discharges are the
main reasons for marine oil pollution (Lucas and MacGregor 2006). Repeated
accidental leak and illegal oil disposal impact on the sea ecosystems severely.
During the years 1970–2010, around 5.71 million tonnes of oil were entered to
seawater due to tanker incidents (Dave and Ghaly 2011). The oil spills have negative
effects on marine life, leisure activities, tourism, and aesthetic appeal. Some soluble
components of oil can enter the food chain via accumulating in the organs of animals
(Mackay and Fraser 2000). The average estimated cost to clean a crude oil spill is
$2730 per barrel (Dave and Ghaly 2011). Since the environmental fallout of cleanup
methods is inevitable, selecting the best methods is based on a trade-off between the
side effects of oil spill and the cleanup method. The type, quantity and characterization of oil spill, age of oil, impact of oil on marine life, environment situation, sea
behavior and weather conditions determine the most effective treatment technique
(Choi and Cloud 1992; Lessard and Demarco 2000; Buist et al. 1999). Several
methods including burning, use of dispersants, mechanical recovery, bioremediation, and use of solidifiers are applicable as response to an oil spill (Dave and Ghaly
2011; Ismail et al. 2019). In bioremediation, microorganisms degrade and metabolize chemical materials in order to restore the environment quality. The ubiquitous
microorganisms in the indigenous oil spill site degrade hydrocarbons in marine oil
spills. The specie of microorganisms introduced in the site depends on the process
design, environmental conditions, and the mode of plant operation (Amin et al.
2013). There is an ideal environment for many microorganisms in an activated
sludge system because of the agitation, constant aeration, and recirculation. Today,
the activated sludge system widely uses bioremediation processes for both domestic
and sewage wastewaters. The main microorganisms in wastewater are fungi, protozoa, bacteria, viruses, and nematodes. Reduction in the levels of oils, fats, and
greases in sewage is therefore very desirable and an appropriate potential candidate
for bioaugmentation. Biological augmentation includes the addition of archaea or
bacterial cultures in order to speed up the rate of degradation of the pollutants. Use of
bioaugmentation has other positive effects like increasing the efficiency and reduction of the toxic molecules (Brooksbank et al. 2007).
In this chapter, the source of oilcontaminants, the related prevention regulation
and bioremediation techniques, bioremediation mechanisms, its advantages and
disadvantages compared with other treatment methods and factors affecting
390
M. Fatehi et al.