Phytoremediation of chromium, iron and nickel by Indian Rice Plant (Oryza sativa L.): An opportunity for management of multi-metal contaminated tannery wastewaterPhytoremediation of chromium, iron and nickel by Indian Rice Plant (Oryza sativa L.): An opportunity for management of multi-metal contaminated tannery wastewater

Abstract

India is the largest producer of leather and leather products. Tannery industries use a large number of synthetic chemicals for the processing of leather and generate a huge amount of wastewater containing a large amount of potentially toxic heavy metals (PTHMs) making them problematic for next-door soil and water system. Currently, phytoremediation is an inexpensive green technology used to move, eradicate, and stabilized heavy metal contamination from contaminated sludge, soil, and wastewater. In this study, the accumulation and distribution of PTHMs found in tannery wastewater and their physio-biochemical effects on Oryza sativa L. have been studied by ICP-MS, GC-MS, and biochemical analysis. The plant was grown in the soil spiked with a mixture of metals (Cr, Fe and Ni) and their five-level of treatment T1 (25mg/kg); T2 (50mg/kg); T3 (100mg/kg); T4 (200mg/kg) and T5 (400mg/kg). During the experiments, various morphological attributes, oxidative stress, enzymatic activities, chlorophyll, and protein content at the different stage was measured. Further, metal accumulation pattern in different parts of plants was also measured. Results of the study revealed that plant root, shoot length, chlorophyll content, and enzymatic activities were significantly reduced after the treatment with 200 mg/kg PTHMs; whereas oxidative stress was increase compared to control levels. Further, treatment of PTHMs suggested that the rice plant (Oryza sativa L.) is well adapted to tolerate and accumulate a high level of heavy metals (up to 200mg/kg) in the root and shoot of the treated plants. If it is treated above this, then seeds were also affected and not safe for human consumption.