Resource degradation of pharmacy sludge in sub-supercritical system with high degradation rate of 99% and formic acid yield of 32.44%

ABSTRACT

In response to the social goal of ‘carbon peak and carbon neutral’ in the 14th Five-Year Plan of China, this article used Enrofloxacin (ENR), a common antibiotic, as a model compound to study the method of efficiently degrading pharmaceutical sludge and simultaneously producing Formic Acid (FA), hydrogen storage energy, in a sub-supercritical system. The Ni/SnO₂ bimetallic catalyst, which was prepared by the equal volume impregnation method, was used for the liquid phase catalysis. As shown by the results, when the reaction temperature was 330°C, and the addition amount of H₂O₂ was 0.38 mL, the degradation rate of antibiotics could reach 99% after the reaction proceeded for 6 h. In terms of the resource utilization, the yield of FA could reach up to 32.44%. The resource utilization efficiency with Ni/SnO₂ catalyst in sub-/supercritical reaction was about 2.5 times higher than that without catalyst. The kinetic reaction model was established to explore the reaction rate of the antibiotic degradation process. In addition, the E_a and the frequency factor of the reaction were 6455 J/mol and 5.78, respectively. As shown by characterization, the prepared Ni/SnO₂ bimetallic catalyst had good activity and has already passed repeated stability experiments. In short, this method has broad application prospects in antibiotic catalysis and resource degradation.

GRAPHICAL ABSTRACT

KEYWORDS:

• Antibiotic
• formic acid
• sub-supercritical
• hydrogen storage
• carbon neutral

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data used to support the findings of this study are available from the corresponding author upon request.

Additional information

Funding

This work was supported by the Natural Science Foundation of Yunnan Province [grant number 202001AT070088], Open Fund of Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling [2020B121201003], National Natural Science Foundation of China [grant number 52060010], National Key Research and Development Program of China [grant number 2019YFC0214400], Young Top Talent Project of Yunnan Ten Thousand Talents Program [Yunnan Social Communication [2019] No. 206], Analysis and Testing Fund of Kunming University of Science and Technology [2020M20192207064].