Antibiotic Removal in Aquatic Systems Using Anaerobically Digested Sludge-Derived Biochar

Anaerobic digestion is a common method for treating organic waste. However, there is a pressing need to devise suitable solutions for managing the substantial amount of sludge generated during this process. The current study aimed to characterize and utilize anaerobically digested sludge-derived biochar (BC) for the removal of tetracycline (TC) from water. The BC demonstrated a Brunauer–Emmett–Teller (BET) surface area of 6.177 m²/g, a pore volume of 0.0257 cm³/ g, and a pore size of 166.435 Å. In the adsorption experiments, the maximum adsorption capacity was observed at pH 5. Furthermore, the adsorption kinetic and isotherm studies indicated a chemisorptive interaction between TC and BC through monolayer adsorption. The maximum adsorption capacity of BC for TC (54.35 mg/g) was greater than that of other adsorbents (2.71 mg/g ~ 41.35 mg/g), but less than that of activated BCs (274.81 mg/g ~ 288.3 mg/g). In summary, anaerobically digested sludge-derived BC holds significant promise for effective TC removal in water. Further research is required to optimize its adsorption capacity.