Adsorption behaviour and mechanism of tetracycline by sorghum straw-loaded HKUST-1

Tetracycline (TC) is a refractory broad-spectrum antibiotic, that is widely present in the waste discharged from animal husbandry, which will cause serious pollution to the ecological environment of water bodies after discharge, and it can be effectively removed by adsorption. In this work, sorghum straw (SS) was used as the substrate to prepare SS@HKUST-1 composites by in-situ growth of MOFs (HKUST-1) on the surface of SS for the adsorption and removal of TC, investigating the adsorption behaviour and adsorption mechanism of composites on TC. The results showed that the adsorption capacity reached 95mg/g when pH=7, T=25℃ and the load capacity of HKUST-1 is 31%. The adsorption process conforms to the pseudo-second-order kinetic model, and the adsorption isotherm conforms to the Freundlich model, which suggested the existence of multimolecular layer chemisorption between TC and adsorbent. Therefore, SS@HKUST-1 had a good application prospect for tetracycline removal in water.