Precursor-oriented design of nano-alumina for efficient removal of antibiotics

Rapid and efficient removal of environmental antibiotics is vital to curb bacterial resistance. Through rational precursors-oriented design, we attain the best Al₂O₃ absorbent by 500 °C calcination of ammonium aluminium carbonate hydroxide (AACH) precursor from NH₄HCO₃ route (AACH-NH₄HCO₃-500) for fast and efficient removal of tetracycline (TC) and other antibiotics from environmental waters including high-salinity wastewater. AACH-NH₄HCO₃-500 (0.25 g·L^-1) can remove (69.92 ± 1.78)% of aqueous TC (0.025 g·L^-1) within 5 min and (97.62 ± 2.75)% within 2 h, and the adsorption capacity is 444.4 mg·g^-1, which is the highest q_max of TC for the 2 h-adsorptions among numerous adsorbents. AACH-NH₄HCO₃-500 has fine tolerance to the coexisting substances, and can be easily regenerated and reused, and has no harm even discarded. The relations among the synthetic methods, the structural features, and the adsorption functions of Al₂O₃ are disclosed through a systematic comparison of the commercial Al₂O₃ and different Al₂O₃ nanomaterials attained from three precursors produced by five different routes. The reasons behind the exceptional adsorption performance are discussed throughout. Our findings would facilitate the development of excellent adsorbents for removal of other pollutants.