Environmental Engineering Reference
In-Depth Information
that the poised industrial growth would generate 100 million tons of non-hazardous
solid waste, 6-7 million tons of hazardous waste annually.
Thus, every one of us are being exposed to contamination from past and present
industrial practices. The risk to human and environmental health is rising and there
is evidence that this cocktail of pollutants is a contributor to the global epidemic
of cancers, and other degenerative diseases. These pollutants belong to two main
classes: inorganic and organic. The challenge is to develop innovative and cost-
effective solutions to decontaminate polluted environments. Nature's cure using
plant resources (=Phytoremediation) is a sustainable solution for environmental
decontamination. As of now about 1,8000 articles have been published on various
aspects of using biological resources for environmental cleanup starting with only
11 in 1989 (Prasad
2011
; Prasad and Prasad
2012
).
In natural capping technologies (= engineered vegetative capping), natural re-
sources offer great potential to contain and even decompose hazardous chemical
waste. For e.g. the remediation work carried out at Volgermeerpolder, Netherlands
is a classic example wherein the local peat lands exhibited excellent containment
capabilities. Using peat instead of expensive construction materials in the remedia-
tion design resulted in significant reductions in public expenditure. The concept of
the natural cap means that the pollutants are being contained by natural vegetation
and associated processes by exploiting native biodiversity (Prasad
2001
). In the
case of the Volgermeerpolder, Netherlands chemical hazardous waste dump site,
this has been accomplished by creating a living peat land (moors and bogs) on top
of the plastic foil that is used to cover the dumpsite. By the time the foil deterio-
rates, the newly formed peat bog will assume phytostabilization function. In natural
capping technology hydrology (infiltration control), biogeochemistry (isolation and
immobilization of hazardous waste) and ecology (venting explosive and combus-
tible toxic gases, controlling decomposition of organic waste) are integrated/moni-
tored with engineered construction and maintenance
A sustainable and ecofriendly approach for redevelopment of polluted areas is in
increasing demand. Land reclamation by the removal of contaminated soil is often
not a desirable option, particularly for large polluted areas. Conventional remedia-
tion by excavation and land filling or ex situ treatment of polluted soil of such a
large site is very expensive and would have high impact local community and en-
vironment. Mine industry (including abandoned mines) causes environmental pol-
lution and degradation causing loss to biodiversity and national heritage, produces
acid mine drainage (Pelo et al.
2009
; Elshorbagy and Mohamed
2000
).
Air pollution, ecotoxicology and environmental safety are other mine industry
issues of human health concern. In recent years, the potential of plants for environ-
mental cleanup has been widely recognized all over the world. The biodiversity
and naturally operating principles of bio-geo-chemical cycles have unequivocally
demonstrated the role in cleanup of the environment (Bell
2001
; Bengson
1995
;
Bergholm and Steen
1989
; Tordoff et al. 2000).
