Biofortification of iron and zinc from industrial waste sludges using bioremediation techniques

Abstract

newlineIndustrialization generates a huge amount of Industrial sludge that creates a harmful newlineenvironment. Industrial waste sludge generally contains high concentrations of newlinemicronutrients such e.g., iron (Fe) and zinc (Zn). Alleviated nutrient deficiencies newlinecombined with dietary diversification or modification can transform these newlinemicronutrients into a secondary source of mineral nutrients by (a) reducing their newlinetoxic levels in the soil, and (b) enhancing minerals into edible portion of plants. newlineCurrent research is aimed towards utilizing a combined approach of newlinephytoremediation and phytofortification for bioremediation of two types of industrial newlinesludge, red mud (iron rich sludge) and zinc sludge (zinc rich sludge). Physical, newlinechemical and biological characterization of these sludge indicates their potential as a newlinesoil fertilizer for biofortification of iron and zinc in plant species. Based on their newlinehighest Importance Value Index (IVI), plant species were selected which showed newlinehigh adaptation to the contaminated soil. Sonchus asper, Sesbaniapunicea grew well newlineon red mud deposits and Cynodon dactylon, Chloris virgata and Desmostachiya newlinebipinnata on zinc sludge deposits. Rhizospheric and non-rhizospheric soil newlinecharacterization indicates effective restoration of red mud and zinc sludge by these newlineplants. In spiked soil experiments, Spinacia oleracea (Spinach) and Solanum newlinelycopersicum (Tomato) displayed potential of micronutrient uptake indicating that newlinered mud and zinc sludge can act as iron and zinc nutrient in certain plants. newlineAmendment combination of red mud and Zn sludge with press mud was found to be newlinebest in improving soil properties, plant growth and Fe and Zn fortification in edible newlineportion of S. oleracea and S. lycopersicum. Further, inoculation with Fe and Zn newlinetolerant bacterial strains increased the phyto-extraction potentials by S. oleracea and newlineS. lycopersicum. These findings are very promising for increasing plant productivity newlineand health in areas having low iron and zinc bioavailability. Beside this, mineral newlineenric