Production, properties, and applications of pharmaceutical sludge-derived biochar

Pharmaceutical sludge is considered hazardous waste in many countries, and pyrolysis treatment of pharmaceutical sludge is a newly popular field. This study comprehensively examines the effects of various pretreatment pHs on the structure and practical application efficiencies of pharmaceutical sludge-derived biochar. Results revealed that the acidic biochar was not only richer in functional groups, but also had more visible structural defects, making it more favorable for application as a catalyst. Furthermore, the biochar pretreated at pH 3.0 produced the greatest amount of persistent free radicals and hydroxyl radicals. Additionally, the biochar pretreated at pH 3.0 demonstrated the most effective tetracycline removal, with a removal efficiency of 57.84 mg/g-biochar. Compared to the control test, the addition of biochar could achieve considerable bactericidal effect. This paper demonstrates scientific and guiding significance to the pyrolysis process and applications of biochar derived from pharmaceutical sludge.