Removal of tetracycline hydrochloride in aqueous by coupling dielectric barrier discharge plasma with biochar

The use of dielectric barrier discharge (DBD) coupled with biochars (BCs) to remove tetracycline hydrochloride (TCH) in aqueous was studied, where enteromorpha prolifera was used to prepare BCs (BC350, BC500, and BC600). The physicochemical properties of the BCs before and after plasma treatment were systematically investigated. The DBD/BC600 system showed the best removal performance, and approximately 89.36% of the TCH was removed and 6.21 g kWh-1 of energy yield was obtained at 5 min. The removal efficiency of TCH increased with an increase of peak voltage, and the higher TCH removal efficiency was observed from pH = 7.2 to 9.2. Both ?OH and ?O2 ? contributed to TCH removal, implying that the presence of other active species was also involved in the TCH removal. During discharge plasma process, the specific surface areas and the amount of oxygen-containing functional groups of the BC600 increased due to the interaction of BC600 and reactive species. Three possible removal pathways were proposed based on the detected intermediate products.