Purification of sewage wastewater though sand column filter for lessening of heavy metals accumulation in lettuce, carrot and cauliflower

Abstract

Sewage wastewater is rich in mineral nutrients contributed in plant growth and yield. However, accumulation of heavy metals in edible part of vegetables and fruits is dangerous for human health. Current research was conducted with aim to evaluate the performance of sand column filter for removal of heavy metals from sewage wastewater applied to the selected vegetables. Heavy metals content i.e. Pb, Ni, Cu and Fe were estimated higher in untreated sewage wastewater as compared to treated water. Number of leaves, fresh and dry weights of leaves, roots and total biomass of lettuce, carrot and cauliflower were improved due to irrigation of unfiltered sewage wastewater as compared to sewage wastewater. Curd diameter, fresh and dry weights of curd, and stem fresh weight of cauliflower, root length and diameter of carrot enhanced because of unfiltered sewage wastewater than treated sewage wastewater. The accumulation of heavy metals i.e. Pb, Ni, Cu and Fe was higher in roots, leaves and edible parts of the selected vegetables. In the present study, Cd and Cr concentrations were not affected from filtration process through sand column filter. Conclusively, filtration through sand column filter is very effective for removal of heavy metals from sewage wastewater to irrigate agricultural lands.