(562bd) Degradation of Pharmaceutical Compound Diclofenac in Aqueous Solution By Horizontal Continuous-Flow Dielectric Barrier Discharge

Degradation
of pharmaceutical compound diclofenac in aqueous solution by horizontal
continuous-flow dielectric barrier discharge

Yinhai Yang, Lecheng Lei,Bin Yang*

Key Laboratory of Biomass Chemical Engineering of
Ministry of Education, College of Chemical and Biological Engineering, Zhejiang
University, Hangzhou, P. R. of China, 310027

keyangb@zju.edu.cn

Diclofenac
(DCF)£¬a
recalcitrant pharmaceutical residue is difficult to be removed by traditional
treatments in water. This paper investigates degradation of diclofenac in a
horizontal continuous-flow dielectric barrier discharge (DBD) system. Some
factors, such as peak voltage, discharge distance and initial concentration were
studied to explore influence mechanism for degradation efficiency and yield of
diclofenac. As the peak voltage increased from 12 to 15kV, the degradation rate
increased, while yield increased first then decreased. While the degradation
rate increased with the reduction in discharge distance. At lower initial
concentration, the degradation rate is higher with same time treatment. After
30 min discharge treatment, removal of DCF can reach 97.6% and the degradation
yield was 0.245g/kWh for the initial concentration of 1mg/l. The decomposition
of DCF followed first-order reaction and the rate constant respectively were
0.0893min^-1, 0.0604min^-1, 0.0476min^-1, 0.0428min^-1
at the initial concentration of 1mg/l, 10mg/l, 20mg/l, 40mg/l. Degradation
intermediates during discharge treatment was identified by LC-MS and the
possible degradation pathway was proposed. The total organic carbon (TOC)
remained high and only a fraction of DCF was mineralized when DCF was almost
removed completely. The results confirmed DCF can be removed efficiently and
mineralized inefficiently, which means that DBD is expected to be a promising
water treatment technology.

Acknowledgement:

This
work was supported primarily by the National Nature Science Foundation of China
(NSFC) (No. 21878271, and 21878270).

References:

1. Magureanu, M. . (2015).
Degradation of pharmaceutical compounds in water by non-thermal plasma
treatment. Water Research, 81, 124-136.

2.    Rodriguez-Narvaez,
O. M. Peralta-Hernandez, J. M., (2017). Treatment Technologies for Emerging
Contaminants in water: A review. Chemical
Engineering Journal, 323,
361-380.