Preparation of copper modified biochar and its effect on catalyzing persulfate to remove the tetracycline from water

Abstract

Copper modified corn stalk biochar(CBC) was prepared by hydrothermal method and used as a catalyst to activate potassium persulfate(PS) to remove tetracycline (TC) from water. The results showed that CBC+PS system had high efficiency and stability for TC removal. Under the conditions of solution pH=7, PS dosage of 3 mmol/L, and CBC dosage of 0.5 g/L, the removal rate of TC with mass concentration of 20 mg/L by the CBC+PS system reached 84.46% within 10 min, and 96.75% after 2 h. Mechanism study indicated that Cu, hydroxyl and carboxyl groups supported on CBC surface could promote electron transfer, and then accelerate the production of reactive oxygen species such as SO4·- and·OH. After 5 cycles experiments, the removal rate of TC could still be maintained at 85.62%, which showed that CBC had good stability and reusability. This study provided an efficient and stable TC removal system, and also provided a new way for the recovery and reuse of corn stalk.

Keywords

• copper modified
• hydrothermal method
• corn stalk biochar
• persulfate
• tetracycline