A Study of Contaminated Soil in Urban Area of Aligarh and Reduction of Heavy Metals Using Phytoremediation Method

Abstract

Contamination of soil in the urban areas has been a major environmental problem among the fast industrializing cities in India. In the Aligarh urban area which has a high density of industrial activities, metal-based workshops, automotive emissions and unchecked disposal of wastes, heavy metals including lead (Pb), cadmium (Cd), chromium (Cr), nickel (Ni), and zinc (Zn) have been found to be accumulated significantly. Such pollutants are very dangerous to human health, the stability of the ecology and the productiveness of the soil as they are not biodegradable and are persistent. This paper examines the levels of the metal-pollution of 110 soil samples representing different industrial, road, waste-dump, and residential areas in Aligarh, and quantifies these metals using Atomic Absorption Spectrophotometry (AAS). The study also assesses the efficacy of phytoremediation by growing 3 species of hyperaccumulator plants Brassica juncea, Helianthus annuus, and Vetiveria zizanioides in 60 days in polluted soil. The findings suggest that the majority of samples are of moderate to high contamination with chromium, lead, and nickel indicating a high level of contamination. The phytoremediation experiments showed that the levels of metals were reduced significantly, which proved the ability of the plant-based remediation as an efficient, cost-effective and sustainable approach to restore the soil. The researchers recommend the use of phytoremediation as a long-term remedy in alleviating heavy-metal pollution in urban settings and should be incorporated in the city ecology planning in Aligarh.