23.3.3.3 Polycyclic Aromatic Hydrocarbons
The co-composting method is very suitable in the case of PAHs, in view of the fact
that these contaminants may be hardly removed using other biodegradation methods.
The volume of literature dealing with this topic, and also the number of cases of
application in practice corresponds to this. Especially a comprehensive review by
Antizar-Ladislao (2010) may be recommended. A summary table describing a
number of practical applications of the co-composting method may also be found
in review by Loick (2009). Generally, it can be stated that co-composting of
PAH-contaminated materials is a very efficient bioremediation approach.
23.3.3.4 Explosives
One of the first applications of the co-composting method in practice was its
utilization for removing explosives by the United States Army. The first tests of
this method were carried out already in 1986 (Doyle 1986). At present, it is one of
the methods recommended by the United States Army for removing explosives from
contaminated soil (Jenkins and Vogel 2014). A US EPA study contributed to that
significantly. US EPA (1997) has evaluated composting as an ex situ solid phase
biological treatment technology to degrade nitroaromatic and nitramine compounds
in soils. Treatability study at the Umatilla Army Depot Activity site in Hermiston,
Oregon demonstrated that composting is an alternative treatment to incineration for
remediating these compounds. Composting has been selected as the treatment for
15,000 tons of TNT (2,4,6-trinitrotoluene), RDX (hexahydro-1,3,5-trinitro-1,3,5triazine, Royal Demolition eXplosives) contaminated soils at Umatilla. Using
composting instead of incineration, Umatilla saved approximately $2.6 million.
Cleanup goals for Umatilla were established at concentrations of less than 30 mg/
kg for TNT and RDX. The project exceeded these expectations by achieving
undetectable levels of explosives. Contaminant by-products were either destroyed
or permanently bound to soil or humus (US EPA 1994).
23.3.3.5 Pesticides
Pesticides are often present in agricultural waste to be composted. In the course of
the composting process, the pesticides should be degraded because of their possible
toxic effects on people as well as on other environmental components, especially on
plants that may be endangered by the presence of herbicides in the compost.
During the composting process, a number of pesticides are degraded indeed,
which also results in utilization of the co-composting method for the target decontamination of materials with pesticide content. However, certain recalcitrant substances, such as the majority of chlorinated aromatic pesticides (like DDT, lindane,
aldrin, etc.), are not degraded much in the compost because the chlorine removal
from the aromatic ring occurs in anaerobic conditions. Büyüksönmez et al. (1999)
486
O. Lhotský et al.
The co-composting method is very suitable in the case of PAHs, in view of the fact
that these contaminants may be hardly removed using other biodegradation methods.
The volume of literature dealing with this topic, and also the number of cases of
application in practice corresponds to this. Especially a comprehensive review by
Antizar-Ladislao (2010) may be recommended. A summary table describing a
number of practical applications of the co-composting method may also be found
in review by Loick (2009). Generally, it can be stated that co-composting of
PAH-contaminated materials is a very efficient bioremediation approach.
23.3.3.4 Explosives
One of the first applications of the co-composting method in practice was its
utilization for removing explosives by the United States Army. The first tests of
this method were carried out already in 1986 (Doyle 1986). At present, it is one of
the methods recommended by the United States Army for removing explosives from
contaminated soil (Jenkins and Vogel 2014). A US EPA study contributed to that
significantly. US EPA (1997) has evaluated composting as an ex situ solid phase
biological treatment technology to degrade nitroaromatic and nitramine compounds
in soils. Treatability study at the Umatilla Army Depot Activity site in Hermiston,
Oregon demonstrated that composting is an alternative treatment to incineration for
remediating these compounds. Composting has been selected as the treatment for
15,000 tons of TNT (2,4,6-trinitrotoluene), RDX (hexahydro-1,3,5-trinitro-1,3,5triazine, Royal Demolition eXplosives) contaminated soils at Umatilla. Using
composting instead of incineration, Umatilla saved approximately $2.6 million.
Cleanup goals for Umatilla were established at concentrations of less than 30 mg/
kg for TNT and RDX. The project exceeded these expectations by achieving
undetectable levels of explosives. Contaminant by-products were either destroyed
or permanently bound to soil or humus (US EPA 1994).
23.3.3.5 Pesticides
Pesticides are often present in agricultural waste to be composted. In the course of
the composting process, the pesticides should be degraded because of their possible
toxic effects on people as well as on other environmental components, especially on
plants that may be endangered by the presence of herbicides in the compost.
During the composting process, a number of pesticides are degraded indeed,
which also results in utilization of the co-composting method for the target decontamination of materials with pesticide content. However, certain recalcitrant substances, such as the majority of chlorinated aromatic pesticides (like DDT, lindane,
aldrin, etc.), are not degraded much in the compost because the chlorine removal
from the aromatic ring occurs in anaerobic conditions. Büyüksönmez et al. (1999)
486
O. Lhotský et al.