Lead-Immobilization, transformation, and induced toxicity alleviation in sunflower using nanoscale Fe°/BC: Experimental insights with Mechanistic validations
Muhammad Rizwan Aslam, Muhammad Waris, Ihsan Muhammad, Maqbool Ahmed, Zahid Khan, Zobia Jabeen, Mohammad Yakoob Zehri, Muhammad Arsalan, Sidra Rehman, Abeer Alnasrawi, Jawaher Alkahtani, Mohamed S. Elshikh, Muhammad Rizwan, Shoaib Raza, Jinsong Deng, Adnan Raza Altaf
Abstract
Lead (Pb) is a biologically non-essential element in the soil that brutally affects plants and other living organisms in soil; hence, its removal has become a worldwide concern. In this work, a multifunctional nanoscale zerovalent-iron assisted biochar (nFe°/BC) was used to minimize the Pb bioavailability in soil with aim of alleviating the Pb-induced toxicity in sunflower. Results revealed that nFe°/BC treatment had significantly improved plant growth (58%), chlorophyll contents (66%), intracellular permeability (60%), and ratio factor (93%), while decreasing the Pb uptake (78%) in plants. The Pb-immobilization and transformation mechanisms were proposed, suggesting that the presence of organic functional groups over the nFe°/BC surface might induce the complex formation with Pb by the ions exchange process in soil solution. The XPS analysis confirmed that surface-active components (Fe+, O2−, O*, C═O) were the key factor for high Pb-immobilization within soil matrix. In addition, 87% of stable Pb species, including PbCO3, PbO, Pb (OH)2, and Pb-O-Fe were found in the soil surface. Current findings have exposed the diverse functions of nFe°/BC on plant health and established a phenomenon that nFe°/BC application could improve the plant agronomic attributes by regulating the homeostasis of antioxidants and Pb uptake.