Phytoextraction potential of different grasses for the uptake of cadmium and lead from industrial wastewater

Abstract

Industrial wastewater contains a variety of contaminants like salts, organic carbon, and heavy metals. Among the heavy metals, cadmium (Cd) and lead (Pb) are considered highly toxic even at low concentration. These metals could enter the food chain through a process of phytoassimilation, hence, lethal for living beings. The present study aimed to investigate Cd and Pb phytoextraction in four grass species viz. Dhab (Desmostachya bipinnata), Sporobolus (Sporobolus arabicus), Kallar (Leptochloa fusca) and Para grass (Brachiaria mutica) from industrial wastewater. The grasses were grown hydroponically in plastic pots in industrial wastewater as growth medium under greenhouse conditions. The experiment trial was arranged following completely randomized design (CRD) with three replicates. Results showed that B. mutica had maximum shoot metal content (Pb = 21, Cd = 0.66 mg kg-1 dry matter), shoot metal uptake (Pb = 201.8, Cd = 6.39 µg plant-1), translocation factor (Pb = 0.73, Cd = 0.55), shoot dry matter (28.8 g pot-1), and root dry matter (4.2 g pot-1). Root Pb concentration was highest in B. mutica followed by D. bipinnata and L. fusca. Whereas S. arabicus showed depressed growth, minimum shoot metal accumulation and uptake potential. Thereby among the tested grass species B. mutica could be suitable option to remediate industrial wastewater contaminated with moderate levels of Pb and Cd.

Keywords

• metal uptake
• para grass
• kallar grass
• dry biomass
• metal concentration