A conjugative study of Typha latifolia for expunge of phyto-available heavy metals in fly ash ameliorated soil

Abstract

With the ever-increasing demand for coal, the drawbacks associated with it also increase. Accelerating accumulation of fly ash, a byproduct in coal combustion processes, is of major environmental concern at present. Fly ash finds its maximum utilization in concrete and cement factory due to its pozzolanic property. However, fly ash is also used in the agricultural division as a “fertilizer” especially in West Bengal. However, there is no upper limit to how much fly ash should be added to agricultural soil. Current study deals with fly ash, that has been mixed with soil in four proportions namely, 0% (FA0), 25% (FA25), 50% (FA50) and 75% (FA75). A wetland emerged plant – Typha latifolia - has also been incorporated in the system. Mobility and metal(loids) relation has been established determining soil-ash physico-chemical properties along with nutritional enrichment to the plant system. Sequential Extraction methods are therefore employed to examine the element speciation. Application of 25 percent Fly ash was found to enhance the N(0.11%), P(0.09%), K(0.051%) and Si(7.7%) availability in soil and also resulted in better plant growth and xylem integrity as justified by electron microscopic observation. At end of final sampling, total arsenic concentration was 50.07±0.25mgKg–1 in Typha associated sample comparing to 59.51±0.19mgKg-1 in without Typha system using 25% ash. This study reflects the utility strategies of fly ash and Typha latifolia in combination for the better expunge of phyto-available metals form agricultural soil during a stop gap, before further crop production particularly another wetland plant, rice.