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– Metal smelting
– Mining
– Treating timber with preservatives
– Use/production of paint/pesticide and other chemicals
• Movement of pollutants into water from geological deposits, like by drilling
wells (WHO 2010a)
• Natural routes such as
– Dissolving of minerals in ground/surface water
– Volcanic activity
– Windblown dust
– Sources like mine drainage water
Contamination of groundwater due to seepage of pollutants through damaged
liners in landfill sites or from waste dump site is key challenge with respect to public
health. Permeable reactive barriers (PRBs) (Santisukkasaem and Das 2018) are one
of the technologies that have been tried in several developed countries.
In the said technology, barrier of reactive material is placed against the
contaminated plume which enters the barrier. The contaminated water entering the
PRB will come out after treatment on other side (Fig. 12.3).
The reactive materials used include the following:
• Zerovalent iron
• Biological barriers comprising microorganisms
• Zeolite
GROUNDWATER TABLE
TREATED WATER
CONTAMINATED
Fig. 12.3 Permeable reactive barrier
12 Restoration