One-pot preparation of layered double oxides-engineered biochar for the sustained removal of tetracycline in water

[Display omitted] •Successful loading of Mg-Al-LDOs onto biochar made from bagasse was achieved.•Pore structure and surface properties of modified biochar (BC-MA) were optimized.•Maximum capacity of tetracycline sorption on BC-MA could be up to 250.6 mg g−1.•Mechanisms engaged in tetracycline removal were clarified.•Excellent sustainable regeneration of BC-MA could be obtained by NaOH washing. Tetracycline (TC) and sugarcane bagasse had both exerted enormous strain on environmental security. In this work, new composite adsorbent designed by impregnating bio-waste bagasse with magnesium–aluminum layered double oxides (BC-MA) was innovatively brought forward for TC removal. Benefiting from the abundant adsorption sites supplied by developed pores structure (0.308 cm3·g−1), enlarged surface area (256.8 m2·g−1) and reinforced functional groups, the maximum adsorption amount of BC-MA for TC reached 250.6 mg g−1. Moreover, BC-MA displayed desirable adsorption capacity in diverse water environments coupled with excellent sustainable regeneration ability. The absorption process of TC by BC-MA was spontaneous and endothermic, and the pivotal rate-limiting stage pertained to intraparticle diffusion. The mechanisms proposed here mainly concerned π-π interactions, pore filling, complexation and hydrogen bonding. These findings suggested that the synthesis of modified biochar from bagasse would offer new opportunities for simultaneous waste resource reuse and water pollution control.