Characterization and experimental evaluation of cow dung biochar + dolomite for heavy metal immobilization in solid waste from silica sand purification

The synergy of biochar and dolomite for handling heavy metals (Cd and Ba) in solid waste was evaluated by physically mixing cow dung biochar (CDB), prepared via pyrolysis method, and agricultural dolomite. The morphology of biochar and dolomite was fine with uneven grains and pores. The materials contained metal oxides such as MgO, CaO, Fe₂O₃, SiO₂, K₂O, and Al₂O₃, which play an important role in enhancing the adsorption process because of their high porosity for absorbing heavy metals. The Fourier-transform infrared spectroscopy spectrum of biochar contained carbon atom groups such as aromatics, ethers, ketones, and alcohols. By contrast, amine elements (NH₂) in dolomite played a role in immobilizing heavy metals with a complexation process between the ligand and the central atom (Cd and Ba).