AbstractBACKGROUNDIn the current work, the conventional pyrolysis technique was replaced by new concentrated solar power (CSP) driven technique to fabricate and modify biochar (BC) for more sustainable, energy independent, cost‐effective, and ecofriendly pyrolysis processes. Double‐glazed vacuum tube was used as a reactor for pyrolysis along with solar tracking system on CSP plant, meanwhile nitrogen flow was maintained during pyrolysis to create an inert environment. Further, a novel approach was used to modifying BC by loading bimetal oxide (Mn‐Ferrite) on pristine biochar (P‐BC) using pre‐ and post‐treatment to enhance its sorption capacity for anionic aromatic pollutant i.e., Eriochromie Black T (EBT) dye from aqueous solution.RESULTSFerric chloride hexahydrate (FeCl3·6H2O) and Ferrous sulfate heptahydrate (FeSo4·7H2O) were used to develop magnetic nanoparticles (MNPs) γ‐Fe2O3 by co‐precipitation technique. Both Biomass and P‐BC were treated with MnCl2·4H2O and MNPs to fabricate an innovative bi‐metal oxide (MnFe2O4) biochar. The characterization of modified biochars via Elemental analyzer, SEM (scanning‐electron‐microscopy), BET (Brunauer–Emmet–Teller), XPS (X‐ray‐photoelectron‐spectroscopy), FTIR (Fourier‐transform‐infrared‐spectra), and VSM (Vibrating‐sample‐magnetometer), ensured the loading of magnetic bimetal oxide over P‐BC. Various kinetic and isotherm models were employed from which pseudo‐second‐order have proven to be the best fit kinetic model on all types of BCs with highest correlation coefficient value (R2 = 0.999). While among isotherm models, Langmuir demonstrated best regression coefficient (R2 = 0.98) and Qmax for EBT was up to 121.95 mg·g−1.CONCLUSIONSAltogether, the results indicated that innovative Mn‐ferrite loaded BC has better sorption ability to EBT than simple metal oxide of Mn and Fe. © 2021 Society of Chemical Industry (SCI).