Effects of Sepiolite and Palygorskite Additions on Cd and Pb Uptake from a Contaminated Soil by Spinach (Spinacia oleracea)

Document Type : Research Paper

Authors

Abstract

Limited information is available about the ability of clay minerals such as sepiolite and palygorskite to reduce bioavailability of Pb and Cd for plants. A pot experiment was conducted using a randomized complete block design to assess and compare the ability of Iranian sepiolite (Yazd) and Spanish palygorskite (Tolsa Co.) on biomass production and uptake of Pb and Cd from a contaminated soil by spinach. A soil sample (0-30 cm depth) was taken from research farms of Shahid Chamran University of Ahvaz and artificially contaminated with Pb and Cd solutions (150 mg/l). Treatments included polluted soils with no amendments (control), with 20 g kg-1 sepiolite, and with 20 g kg-1 palygorskite. Six seeds of spinach (Virofly cultivar) were then planted into each pot and loss of water was replenished daily using distilled water to reach field capacity throughout the experiment. After 45 days, the plants were harvested and the concentrations of Pb and Cd in roots and shoots were determined using atomic absorption spectroscopy. The results showed that application of both sepiolite and palygorskite significantly increased root and shoot dry biomass compared with the control. However, after application of both sepiolite and palygorskite, bioaccumulation factor (BF) of Cd and Pb in roots of spinach decreased by 78.1% and, 56.2% and in shoots by 91.7% and 75%, respectively. Both sepiolite and palygorskite minerals showed more tendency to adsorb Pb than Cd. The results demonstrate that both sepiolite and palygorskite could be effective in reducing Pb and Cd bioavalability and accumulation in spinach. However, sepiolite was more effective than palygorskite.

Keywords

Iranian Journal of Soil Research
Volume 29, Issue 4 - Serial Number 4
February 2016
Pages 435-448

Files

Share

How to cite

Statistics