Cadmium Removal from Aqueous Solutions Using <I>Macaranga peltata</I>:A Potential Plant for Phytoremediation

Abstract

The concentration of heavy metals in the environment is increasing at an alarming rate due to the high rate of industrialisation and intensive agricultural practices over the past few decades. Since most of the heavy metals are persistent and toxic in nature, they significantly reduce agricultural productivity and pose severe threat to human beings through food chain contamination. In recent years, phytoremediation has gained considerable attention as a solar driven green technology for the removal of heavy metals. In the present study we examined the Cadmium (Cd) removal potential of Macaranga peltata -one of the woody species emerging in early successions -found very common in Kerala. The experiment was conducted in batch mode for a period of 20 days in three different concentrations of Cd (0.5, 1.5, and 2.5 mg/L) in two different mediums (distilled water and 10% Hoagland nutrient solution). The percentage removals of Cd by M. peltata from three treatments in distilled water were 98, 93 and 89% respectively, where as in the case of Hoagland nutrient medium it was 90, 89 and 82% respectively. The results show higher removal efficiency in distilled water as compared to Hoagland nutrient medium. The analysis of the plants revealed that most of the Cd was accumulated in the roots followed by stem and leaf. Cd accumulation also affected the chlorophyll content of the plant at higher concentrations. The study shows that M. peltata is a promising plant for the phytoremediation of Cd. Since most of the earlier studies on phytoremediation were carried out using smaller plants with less biomass production and growth rate, the use of M. peltata -one of the fastest growing tree species in the present study receives special attention.