Spirodela polyrhiza: A Potential Accumulator of Pb from Contaminated Water

Abstract

Today environmental pollution is a matter of great concern. Amongst the different causes, pollution caused by heavy metals is a major issue. Due to increased industrialization and urbanization, use of different heavy metals like Pb, Cu, Zn, Cd has increased manifold. These are toxic metals that have hazardous effects on all living forms. Lead (Pb) is one such pollutant that may disrupt the food chain and has major health effects. With the objective to find an eco-friendly cost-effective treatment process for Pb, phytoremediation of Pb contaminated water has been studied in the present investigation. Phytoremediation is a green technology that utilises a plant’s ability to remove and accumulate different toxic pollutants in their biomass. Duckweed Spirodela polyrhiza were exposed to different Pb concentrations of 0.91, 1.97, and 2.88 mg/L for a period of 22 days. Spirodela polyrhiza was found to remove 93.19% at 0.91 mg/L that decreased to 82.23% at 1.97 mg/L Pb contaminated solution. Thus removal percentage and rate of removal was found to decrease with increase in initial Pb contamination. Relative growth factor in Spirodela polyrhiza exposed to different initial Pb concentrations reduced significantly with increase in concentrations. Pb accumulation capacity of Spirodela polyrhiza was found to increase with increase in initial Pb concentration. An accumulation of 7051 ± 631.54 mg/kg was obtained by Spirodela polyrhiza at initial Pb concentration of 2.88 mg/L. The study thus concludes that Spirodela polyrhiza is a suitable candidate for the phytoremediation of low concentration of Pb from contaminated water.