problems for humans. Thus, remediation technologies to treat oil contamination
have attracted great attention. There are two main categories of oil removal technology: remediation and bioremediation. The type and the quality of the contaminants,
the type and the environmental situation of the contaminated site, and the cost of
treatment determine the best remediation method.
We reviewed the physical and chemical remediation as well as bioremediation
methods and in situ and ex-site processes. Physical methods are eco-friendly but
these are expensive, time-consuming methods and need a large number of personnel
and equipment, resulting in failure to remove spilled oil in harsh and frozen sea
conditions. The main disadvantage of the chemical methods is the formation of
secondary pollutants, which may have irreparable effects on marine life. However,
chemical agents can be used to improve physical removal methods. On the other
hand, sorbents are the alternative choice for spilled oil removal process. Natural
sorbents are biodegradable, low cost, and eco-friendly compared to synthetic sorbents, but their sorption efficiency is lower than that of synthetic and inorganic
sorbents. Bioremediation can be applied in all weather conditions, needs less
manpower, is cost-effective, and can mineralize oil to CO 2 and H 2 O. However,
low capacity of microbes to survive against oil pollutants is its limitation factor. In
addition, the performance of bioremediation depends on the indigenous microorganisms and the available nutrients at the contaminated site. As a most important
conclusion, it should be notified that the most powerful remediation response to the
oil spill is a combination of physical, chemical, and biological treatments, which is
also the most cost-effective method.
Keywords Water pollution · Oil spill · Remediation · Bioremediation · Sorbent ·
Oil-contaminated water · Characteristics of oil spill · Microorganisms · Physical
methods · Chemical methods
12.1 Introduction
Nowadays, water pollution with spilled oils has become a global environmental
concern. Oil spills are caused by industrial accidents, transport accidents, routine
ship operations, and illegal discharge of industrial or domestic wastewater
(Putatunda et al. 2019; Jernelöv 2010). Most sources of oil are insoluble in water
and float on the top of water surface due to their lower specific gravity. Once an oil
spill occurs on the surface of water, the oil is subject to several processes simultaneously, such as floating, spreading, drifting, dispersion, emulsification, sinking,
photolysis, formation of tar ball, evaporation, and biodegradation (Fig. 12.1)
(Al-Majed et al. 2012). The emulsion and floating film of spilled oil influences on
the marine life, the quality of drinking-water sources, air, economy, and tourism.
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M. Fatehi et al.
have attracted great attention. There are two main categories of oil removal technology: remediation and bioremediation. The type and the quality of the contaminants,
the type and the environmental situation of the contaminated site, and the cost of
treatment determine the best remediation method.
We reviewed the physical and chemical remediation as well as bioremediation
methods and in situ and ex-site processes. Physical methods are eco-friendly but
these are expensive, time-consuming methods and need a large number of personnel
and equipment, resulting in failure to remove spilled oil in harsh and frozen sea
conditions. The main disadvantage of the chemical methods is the formation of
secondary pollutants, which may have irreparable effects on marine life. However,
chemical agents can be used to improve physical removal methods. On the other
hand, sorbents are the alternative choice for spilled oil removal process. Natural
sorbents are biodegradable, low cost, and eco-friendly compared to synthetic sorbents, but their sorption efficiency is lower than that of synthetic and inorganic
sorbents. Bioremediation can be applied in all weather conditions, needs less
manpower, is cost-effective, and can mineralize oil to CO 2 and H 2 O. However,
low capacity of microbes to survive against oil pollutants is its limitation factor. In
addition, the performance of bioremediation depends on the indigenous microorganisms and the available nutrients at the contaminated site. As a most important
conclusion, it should be notified that the most powerful remediation response to the
oil spill is a combination of physical, chemical, and biological treatments, which is
also the most cost-effective method.
Keywords Water pollution · Oil spill · Remediation · Bioremediation · Sorbent ·
Oil-contaminated water · Characteristics of oil spill · Microorganisms · Physical
methods · Chemical methods
12.1 Introduction
Nowadays, water pollution with spilled oils has become a global environmental
concern. Oil spills are caused by industrial accidents, transport accidents, routine
ship operations, and illegal discharge of industrial or domestic wastewater
(Putatunda et al. 2019; Jernelöv 2010). Most sources of oil are insoluble in water
and float on the top of water surface due to their lower specific gravity. Once an oil
spill occurs on the surface of water, the oil is subject to several processes simultaneously, such as floating, spreading, drifting, dispersion, emulsification, sinking,
photolysis, formation of tar ball, evaporation, and biodegradation (Fig. 12.1)
(Al-Majed et al. 2012). The emulsion and floating film of spilled oil influences on
the marine life, the quality of drinking-water sources, air, economy, and tourism.
388
M. Fatehi et al.