EDTA-Enhanced Phytoextraction of Cd, Pb, and Cr from Industrially Contaminated Soil by Brassica juncea

Abstract

Heavy metal contamination of industrial soils is a persistent environmental concern because of the toxicity and non-biodegradable nature of cadmium (Cd), lead (Pb), and chromium (Cr). This study evaluated EDTA-assisted phytoremediation using Brassica juncea in contaminated soils collected from the Bhiwandi industrial region, Maharashtra, India. Soil samples were characterised for physicochemical properties and metal concentrations, and B. juncea was cultivated under greenhouse conditions. A 0.1 M EDTA treatment was applied to enhance metal availability. Metal uptake was quantified by atomic absorption spectrophotometry, while chlorophyll content, antioxidant enzyme activities, bioaccumulation factor (BAF), translocation factor (TF), and removal efficiency were assessed. EDTA treatment increased the uptake and translocation of Cd, Pb, and Cr. BAF values ranged from 2.41 to 5.81, while removal efficiencies were 48.6% for Cd, 62.9% for Pb, and 40.7% for Cr. Heavy metal exposure was associated with reduced chlorophyll content and increased superoxide dismutase and catalase activities, indicating activation of antioxidant defence responses. The findings indicate that EDTA can enhance the phytoextraction performance of B. juncea under the conditions examined. However, the environmental persistence of EDTA and the potential mobility of metal–chelate complexes require careful consideration. Evaluation of biodegradable chelating agents under field conditions is therefore warranted before broader application of this approach.