STUDY ON PHYTOREMEDIATION POTENTIAL FOR REMOVAL OF TOXIC ELEMENTS

Abstract

There are numerous pollutants that pose threat to the environment on an unprecedented scale. It creates undesirable effects on water, soil, and air as well. It is furthermore an essential concern as the concentration of such elements goes on accumulating in the environment. Remediation of such pollutants by absorption and accumulation in plant or animal tissues is one of the most effective natural methods of waste treatment. The use of live plants for the removal of environmental pollutants is termed phytoremediation. Phytoremediation bears down to the capacity of plants to absorb, accumulate and store various elements from water and soil into their biomass. The physiology of plants plays a vital role in phytoremediation as not all plants can hyper accumulate contaminants. Remediation of contaminants includes several mechanisms involved for uptake of metals from polluted soils or waters for treatment and render them non-toxic. Along with phytoremediation, this project also studies the properties and health impact of various toxic elements in the environment that threaten human and animal health. The project evaluates phytoremediation through an experimental study and a case study. Experimental study was accomplished by using kitchen wastewater generated from post-cooking washing of utensils as feed to plants for phytoremediation. It included testing of water quality parameters such as pH, electrical conductivity, total dissolved solids, biochemical oxygen demand, chemical oxygen demand total phosphate for water at the inlet and excess draining water from the outlet of the pot. The case study involved study on phytoremediation potential of twelve wild plant species for removal of toxic elements and assesses their vi phytoremediation potential for removing toxic elements such as arsenic, cadmium, chromium, copper, nickel, lead, and zinc from contaminated soil. Plants remove elements by absorbing and binding various elements organically in their biomass. Hence, the phytoremediation potential of different species of plants shall be assessed for absorbing different elements. The experimental study rather being of a short duration concludes that there is good scope for plants to absorb organic materials and stabilise kitchen wastewater. The case study reveals that, during the first year of growth, all the species of plants have absorbed and stored toxic elements in their biomass, especially in their shoot, leaves, and flowers. Still, a minimal amount was found to accumulate in the roots. Also, due to the photosynthetic activity, leaves contain the most concentration of the absorbed element. On the contrary, after the second year of growth, it is evident that roots are actively involved in storing toxic elements in them. The maximum concentration of toxic elements is found in roots. In contrast, the concentration of toxic elements does not seem to increase significantly in other parts of the plant.