12

Biology and Biotechnology of Environmental Stress Tolerance in Plants, Volume 3

1.3.2.2 LAND FARMING OPERATION

This is a basic technique of excavating and spreading polluted soil and prepa­

ration of bed by regular tiling until the pollutant in the soil gets degraded.

The aforementioned process is limited, and the handling of the soil was done

at 10–35 cm, on the superficial surface. It is the most efficient in eliminating

PAH and PCP.

1.3.2.3 BIOPILE SYSTEM

It is a combination of composting and land cultivation. In this process, the

engineered cell is designed as composted aerated piles. It is also used for the

treatment of petroleum hydrocarbons and the extraction of pollutants from

the surface. This process is the modification of land farming which aims

to monitor the physical losses of the pollutant that leads to leaching and

volatilization (Williams, 2006). It provides indigenous aerobic and anaerobic

microorganisms with a congenial habitat for their proliferation.

1.3.2.4 SLURRY PHASE SYSTEM

Contaminated materials, microorganisms, and water are formulated into

slurry within the bioreactor or fermentor. The bioreactors are designed to

promote microbial degradation.

1.3.2.5 USE OF GENETIC ENGINEERING

The use of DNA technology among the various forms of biotechnology has

the potential of producing new combinations of genes that have not existed

in nature before. The use of restriction enzymes has enabled the isolation

of particular DNA fragments that can be transferred to another organism

lacking the same. Genes that code for environmental pollutant metabolism,

such as PCBs and other xenobiotic compounds, are often found on plasmids,

but not always. A modern viewpoint on bio-waste treatment has opened up

the possibility of genetic transfer to non-biodegrading microbes (Sayler &

Ripp, 2000). The recombinant DNA has the potential to multiply and may

grant the unique derivative capacity to detoxify environmental pollutants.