|
Remediation of heavy metals from
watercourses is of particular concern because of the presence of
heavy metals in the environment. There is range of technologies
being carried out for the removal of inorganic pollutants from
wastewater. The conventional method of removing toxic heavy metals
is chemical precipitation, reverse osmosis, coagulation, flotation,
and ion exchange are expensive and produces large amounts of sludge
and toxic products which have negative impact on environment.
Therefore, a green technology using agricultural waste as
bio-adsorbent has received more attention for the removal and
recovery of heavy metals because it uses environment friendly,
sustainable, and cost-effective. The majority of the agricultural
waste biomass belongs to the alcohol family, carbonyl, amide, amino,
etc., which have an affinity for heavy material ions to form
material complexes or chelates. The methodologies of the
bio-absorption process include chemisorption, complexation, face
adsorption, periphrasis through pores, and ion exchange. The present
review presents different types of bio-adsorbents, their uses, and
their mechanism of action. Furthermore, these bio-adsorbents can be
modified for better efficacy and reused repeatedly. This review also
includes several ways for improving the efficiency of bio-adsorbents
and physicochemical conditions for extracting heavy metals from
waste streams. |
| |
|
|
Key words: Bio-adsorbents, Agricultural wastes,
Eradication, Heavy metals, Remediation. |
|
