Use of sesame and sorghum crops to verify the remediation of contaminated sewaged soils

Abstract

At the time being, treated sewage effluent is repeatedly used in farming, particularly in newly reclaimed sandy soils, as it fortify their content of nutrients and organic matter as time goes on, despite there are significant concerns about the long-term accumulation of PTEs in the soil ecosystem. Pot experiment was conducted to verify the effectiveness of bioremediation of two sewaged soils, highly and marginally contaminated, with either canola (Brassica napus) or Indian mustard (Brassica juncea) plants in the absence and presence of AM inoculation, by growing sesame (Sesamum indicum) and sorghum (Sorghum bicolor) plants. Results indicated that the vegetative parameters of both test crops did not show any sign of adverse symptoms when grown in either bioremediated sewaged soils. Phytoremediation with either canola or Indian mustard obviously reduced Cu and Zn contents in both sesame and sorghum plants and completely removed Ni from soil. Both sesame and sorghum plants grown in both bioremediated sewaged soils contained lower PTEs, however, at varying degrees. Zinc equivalent value in marginally and highly decontaminated soils after harvesting either sorghum or sesame obviously decreased compared to control soil. After phytoremediation, the dehydrogenase activity increased in all soils. Generally, the efficiency of phytoremediation with canola far exceeded that with Indian mustard, despite both were effective tools.