26.6 Biotechnological Approaches for the Removal of ECs

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windrows. The windrow can be thoroughly mixed by turning with a commercially

available turning machine. Moisture, pH, temperature, and explosive concentration

are monitored. After the completion of the composting, the windrows would be

disassembled and the compost will be taken to the final disposal area.

26.6.4.6

Land Farming/Land Treatment

Land farming is a simple bioremediation technique in which EC containing waste

or soil will be spread over a prepared bed and periodically tilled until pollutants are

degraded. The goal is to stimulate indigenous biodegradative microorganisms and

to facilitate their aerobic degradation of ECs. This practice is limited to the treat-

ment of superficial 10–35 cm of soil. Since land farming has the potential to reduce

monitoring and maintenance costs, and clean-up liabilities, it has received much

attention as a disposal alternative. Spilled oil and wood-preserving wastes have been

bioremediated by land farming treatments.

26.6.4.7

Biopiling

Biopiles are hybrid of land farming and composting. Essentially, engineered cells

are constructed as aerated composted piles. Adding compost to contaminated soil

enhances the bioremediation. Compost enhances the oxidation of the aromatic con-

taminants of the soil into ketones and quinones, which will eventually disappear.

This method is used for the treatment of surface of EC like petroleum hydrocarbons.

It is a refined version of land farming that tends to control physical loss of the EC

by leaching and volatilization. Biopiles provide a good environment for indigenous

aerobic and anaerobic microorganisms [9].

26.6.5

Phytoremediation

Phytoremediation involves the use of plants and their associated microbes to

accumulate, detoxify, or stabilize EC. It is an environment-friendly and sustainable

means of remediating contaminated soil and water. It has been an important aspect

of constructed wetlands, which is used to detoxify large volumes of wastewater with

dilute concentrations of EC successfully, including petroleum, hydrocarbons, chlo-

rinated solvents, pesticides, explosives, heavy metals, and radio nuclides. The most

important requirement for this method is the use of fast-growing, high-biomass

plants those are capable of uptaking and accumulating large amounts of toxic

metals. Biotechnology makes it possible to isolate such microbes and enrich the soil

so as to enhance phytoremediation by respective plants. The scientific studies on

genetics, physiology, and biochemistry of plant tolerance to inorganic and organic

contaminants have dramatically increased which will be important for improving

the phytoremediation techniques. These techniques for restoring soil at specific

level in determined site will depend on the chemical nature and concentration of the

pollutant and also on the physicochemical and biological characteristics of the soil.

However, there are still some barriers for the adoption of phytoremediation which

will impair the successful application of this remediation technique. This technique

is subdivided into number of phytoprocesses depending on the characteristic used

by the plants to remediate a polluted site.