A novel magnetic S/N co-doped tea residue biochar applied to tetracycline adsorption in water environment

The issue of tetracycline (TC) contamination has attracted widespread attention. Adsorption technology has great potential for application in the field of TC remediation. This study achieved the production of nitrogen self-doped biochar using waste tea leaves as raw materials, and further improved its TC removal effect by doping sulfur elements. A recyclable high-performance TC adsorbent magnetic S/N co-doped tea residue biochar (MSNB) obtained through ferromagnetic modification, which could be used as an effective TC adsorbent. The effects MSNB dosage and initial solution pH on TC removal were evaluated. The recovery performance of MSNB adsorbent on TC was studied. The maximum adsorption performance at 298 K calculated using the Langmuir model was 140.76 mg g(-1). The fitting results of adsorption kinetics indicated that chemical adsorption was main factor affecting the adsorption reaction. After 5 cycles of adsorption, the removal of TC by MSNB remained above 88.30 %. This study could provide theoretical support for the treatment of tetracycline wastewater biochar adsorption.