Investigating phytoremediation potential of Brasica nigra in removal of nickel, zinc and arsenic from contaminated soils

Young Researchers and Elite Club, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran E-mail : Shabnam.saffarian@yahoo.com Fax : 98-21-6691-0454 Manuscript received online 21 June 2014, revised 28 July 2014, accepted 09 October 2014 Phytoremediation is a technology for removing pollutants from the environment or making them inactive. The current study was carried out to examine phytoremediation capability of black mustard (Brasica nigra) for cleaning up the soil contaminated with nickel, zinc and arsenic. To this end, the germination capability of black mustard in remediation of the soil contaminated with different concentrations of nickel, zinc and arsenic ((control sample 0 ppm), 100 ppm, 500 ppm, 5000 ppm, 10000 ppm and 50000 ppm) was examined with three replicates for 120 days. As the obtained results suggest, in high concentrations of nickel, zinc and arsenic (up to 50000 ppm), germination was reduced 90% compared to the control sample. However, no significant difference was observed between the concentrations of 10000 ppm and 50000 ppm in this respect. The lowest germination percentage of 1 ± 0.57 was observed in soils with contamination concentration of 50000 ppm. Comparing the concentrations of nickel, zinc and arsenic in the case soil samples containing black mustard with that of the control samples, it was showed that concentrations of heavy metals have declined 944, 22, 426 and 0.276 ppm in the case samples. The uptake results in the case samples showed that the highest and lowest of the plant up-take were related to zinc (equal to 26.4 ppm) and arsenic (equal to 0 ppm), respectively. Although phytoremediation is a suitable method for reduction of nickel, zinc and arsenic, however studies showed that at concentrations higher than 500 ppm, the method is no longer efficient