Phytoextraction of Few Metals from Flyash Amended Soil by Scirpus littoralis

Abstract

The disposal and treatment of coal fired power plant generated fly ash is a major problem till date.  Wetland plants can be used to extract the heavy metals present in the fly ash from aquatic systems like fly ash ponds or constructed wetland systems. For this purpose Scirpus littoralis, a wetland plant was chosen to assess its phytoextraction potential of Mn, Ni, Cu, Zn and Pb from the fly ash amended soil under ex-situ conditions. Fly ash from Indraprastha Power Plant of New Delhi was dosed in manure mixed garden soil in 25%, 50% and 100%. Soil without fly ash served as control. The plants were grown for three months in waterlogged condition. Each harvesting was done after one month and growth and metal concentration in roots and shoots were estimated. During these three months metal accumulation and plant growth increased with time. It was found that plant growth and phytoextraction of metals was maximum in 25% fly ash amendment. In this study, total phytoextracted metals by Scirpus littoralis, was calculated, as the product of biomass and tissue metal concentration. The concentration of total phytoextracted metal after three months in 25% fly ash dosed plant roots were 6433.96 μg for Mn, 677.43 μg  for Ni, 638.3 μg for Cu, 1264.25 μg for Zn, 409.5 μg for Pb. From the study it was concluded that Scirpus littoralis, can be used for phytoextraction of fly ash at 25% amendment level as this amendment showed maximum growth and accumulation of metals. However, ANOVA at 0.05 significance level showed that the difference in metal content in the plant parts between the different treatment were not statistically significant.