changes during 50 days following preremediation of polluted soil before the formation of biopile and then biostimulation using fishmeal (Dias et al. 2015). Sieving and
aeration of polluted soil before the processing are the important factors in the
efficiency of biopiles (Delille et al. 2008). In order to increase the bioremediation
process in a biopile construction, bulk agents like dust, saw, straw, bark or wood
chips, and other organic compounds can be used (Rodrıguez-Rodrıguez et al. 2010).
Conserving space is the advantage of biopile systems in comparison with other ex
situ bioremediation methods.
Factors Influencing Bioremediation
Indigenous microorganisms like bacteria, yeast, and fungi (Talaromyces,
Cunninghamella, Aspergillus, Amorphotheca, Penicillium, Fusarium, Neosartorya,
Paecilomyces, Graphium) provide a reliable method to remove the exterior contaminants like crude oil (Haritash and Kaushik 2009; Ghanavati et al. 2008; Deshmukh
et al. 2016). In the study by Lee et al. (2015), biodegradation of ligninolytic fungi
was investigated. They proved that in the lignin system there are major enzymes like
peroxidases, lignin, phenol oxidases, manganese-dependent peroxidases, and hydrogen peroxide-producing enzymes that can degrade hydrocarbons. Many researches
have studied the influence of the different environmental factors on biodegradation
of hydrocarbons in crude oil (Cooney et al. 1985). The poor biodiversity of local
microbes, availability of microorganisms, which is limited in the environment,
shortage of local specialized microbes with supplementary substrate properties
(Ron and Rosenberg 2014), accessibility of hydrocarbons-degrading organism,
chemical composition of the hydrocarbons, biological activity optimization, pH,
electron acceptors, energy sources (electron donors), inhibitory substrates or metabolites, temperature, nutrients, and oxygen are the factors that affect
hydrocarbonsbiodegradation. For success, microorganisms should improve their
catabolic activities to convert the pollutants via developing their metabolic capability
by genetic changes, induction of special enzymes and electric enrichment of microorganism. Crude oilhydrocarbons include aromatics, resins (carbazoles, pyridines,
sulfoxides, amides, and quinolines), asphaltenes (esters, ketones, phenols, fatty
acids, and porphyrins), and aliphatics (Al-Hawash et al. 2018), and their degradation
is influenced mainly by their nature and amount. In the marine environment, the
maximum degradation rate is in a temperature range of 15–20
C, while this range in
freshwater is 20–30
C (Al-Hawash et al. 2018). Leaked crude oilhydrocarbons in
water are spread by wind and waves and can form emulations. In the absorption of
hydrocarbons by microorganisms, formation of emulations is a main factor. As a
short list, the biological factors affecting bioremediation are accessibility of
hydrocarbons-degrading organism, local specialized microbes with supplementary
substrate properties, inhibitory substrates or metabolites, and nutrients. In addition,
the chemical and physical factors are chemical composition of the hydrocarbons, pH,
electron acceptors, electron donors, temperature, and oxygen.
12 Remediation of Pollution by Oil Spills
477
aeration of polluted soil before the processing are the important factors in the
efficiency of biopiles (Delille et al. 2008). In order to increase the bioremediation
process in a biopile construction, bulk agents like dust, saw, straw, bark or wood
chips, and other organic compounds can be used (Rodrıguez-Rodrıguez et al. 2010).
Conserving space is the advantage of biopile systems in comparison with other ex
situ bioremediation methods.
Factors Influencing Bioremediation
Indigenous microorganisms like bacteria, yeast, and fungi (Talaromyces,
Cunninghamella, Aspergillus, Amorphotheca, Penicillium, Fusarium, Neosartorya,
Paecilomyces, Graphium) provide a reliable method to remove the exterior contaminants like crude oil (Haritash and Kaushik 2009; Ghanavati et al. 2008; Deshmukh
et al. 2016). In the study by Lee et al. (2015), biodegradation of ligninolytic fungi
was investigated. They proved that in the lignin system there are major enzymes like
peroxidases, lignin, phenol oxidases, manganese-dependent peroxidases, and hydrogen peroxide-producing enzymes that can degrade hydrocarbons. Many researches
have studied the influence of the different environmental factors on biodegradation
of hydrocarbons in crude oil (Cooney et al. 1985). The poor biodiversity of local
microbes, availability of microorganisms, which is limited in the environment,
shortage of local specialized microbes with supplementary substrate properties
(Ron and Rosenberg 2014), accessibility of hydrocarbons-degrading organism,
chemical composition of the hydrocarbons, biological activity optimization, pH,
electron acceptors, energy sources (electron donors), inhibitory substrates or metabolites, temperature, nutrients, and oxygen are the factors that affect
hydrocarbonsbiodegradation. For success, microorganisms should improve their
catabolic activities to convert the pollutants via developing their metabolic capability
by genetic changes, induction of special enzymes and electric enrichment of microorganism. Crude oilhydrocarbons include aromatics, resins (carbazoles, pyridines,
sulfoxides, amides, and quinolines), asphaltenes (esters, ketones, phenols, fatty
acids, and porphyrins), and aliphatics (Al-Hawash et al. 2018), and their degradation
is influenced mainly by their nature and amount. In the marine environment, the
maximum degradation rate is in a temperature range of 15–20
C, while this range in
freshwater is 20–30
C (Al-Hawash et al. 2018). Leaked crude oilhydrocarbons in
water are spread by wind and waves and can form emulations. In the absorption of
hydrocarbons by microorganisms, formation of emulations is a main factor. As a
short list, the biological factors affecting bioremediation are accessibility of
hydrocarbons-degrading organism, local specialized microbes with supplementary
substrate properties, inhibitory substrates or metabolites, and nutrients. In addition,
the chemical and physical factors are chemical composition of the hydrocarbons, pH,
electron acceptors, electron donors, temperature, and oxygen.
12 Remediation of Pollution by Oil Spills
477