The present study was performed to assess Ni-immobilization and the phytoremediation potential of sunflower by the application of quinoa stalks biochar (QSB) and its magnetic nanocomposite (MQSB). The QSB and MQSB were characterized with FTIR, SEM, EDX, and XRD to get an insight of their surface properties. Three-week-old seedlings of sunflower were transplanted to soil spiked with Ni (0, 15, 30, 60, 90 mg kg-1), QSB and MQSB (0, 1, and 2%) in the wire house under natural conditions. The results showed that increasing Ni levels inhibited sunflower growth and yield due to the high production of reactive oxygen species (ROS) and lipid peroxidation. Enzyme activities like superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POX) also increased as Ni levels increased. However, the application of QSB and MQSB reduced Ni uptake, root-shoot, and shoot-seed translocation and decreased the generation of ROS, and lowered the activity of SOD, CAT, APX, and POX, leading to improved growth and yield, especially with MQSB. This was verified through SEM, EDX, XRD, and FTIR. It can be concluded that QSB and MQSB can effectively enhance Ni-tolerance in sunflowers and mitigate oxidative stress and human health risks.
Keywords: Antioxidant enzymes; FTIR; Ni-translocation; PCA; ROS; health risk.
The article focuses on enhancing the phytoremediation remediation potential of Helianthus annuus by using the quinoa stalks biochar (QSB) and magnetic quinoa stalks biochar (MQSB) by immobilization of Ni in soil and ultimately attenuation of oxidative stress in plants and human health risk. Iron enrichment of biochar improves the surface characteristics (surface area, functional groups, porosity, etc.) which help to immobilize metals ions. To the best of our knowledge, QSB and MQSB has never been used before to study the Ni dynamics and for enhancing sunflower phytoremediation potential.