Biochar with improved performance prepared based on “micro-explosive reaction” conjecture for effective removal of antibiotics

In this study, corn and wheat straw biochars (BCS-K-Zn and BWS-K-Zn) were produced through a one-step carbonization-co-activation method utilizing a novel mixed activator (ZnCl 2 or K 2 SO 4 ). The data indicated that their specific surface areas measured 1817.66 and 1509.84 m 2 /g, respectively. This method significantly improved the physicochemical properties of the biochars, particularly the total pore volume, which increased by 26.79 % and 31.54 %, respectively, when compared to the biochars produced from single activator. After analyzing the reactions present in the preparation process, we proposed the hypothesis of “micro-explosion reaction”. Following this, we investigated the removal abilities of biochars using chloramphenicol and tetracycline hydrochloride (CP and TH) as adsorption models. Both biochars demonstrated superior performance in single system and binary system adsorption tests. The maximum adsorption capacities for TH (1782.52 and 1638.44 mg/g) and CP (1368.18 and 1438.22 mg/g) exceed those of most adsorbents. This work aims to not only prepare biochars with enhanced performance to combat antibiotic pollution in water, but also verify the effectiveness of a new preparation technology. This could serve as a novel strategy for further development of lignocellulosic biochars.