TY - JOUR
T1 - Enhanced ultrasonic degradation of acetaminophen and naproxen in the presence of powdered activated carbon and biochar adsorbents
AU - Im, Jong Kwon
AU - Boateng, Linkel K.
AU - Flora, Joseph R.V.
AU - Her, Namguk
AU - Zoh, Kyung Duk
AU - Son, Ahjeong
AU - Yoon, Yeomin
N1 - Funding Information:
This research was supported by the Korea Ministry of Environment, ‘GAIA Project, 2012000550022’ and by the International Research & Development Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (MEST) of Korea (No. 2012K1A3A1A12054908). The authors would also like to thank Dr. Sunkyu Park (North Carolina State University) for providing the biochar.
PY - 2014/2/26
Y1 - 2014/2/26
N2 - This study investigated the degradation of pharmaceuticals (PhACs), acetaminophen (AAP) and naproxen (NPX), via treatment under ultrasonic (US) conditions. The most efficient frequency based on the rate of PhACs degradation and hydrogen peroxide (H2O2) production was found to be 580 kHz when 28, 580, and 1000 kHz frequencies were applied. Additionally, the degradation of PhACs at 580 kHz could be improved by increasing the US-power density and solution temperature. The apparent activation energy of degradation was determined via Arrhenius law to be 10.3 and 11.2 kJ mol-1 for AAP and NPX, respectively, wherein the most favorable degradation pH was acidic. Density functional theory based calculations demonstrated that NPX has 8 barrierless points of reaction compared to AAP having 1 barrierless point. This molecular modeling analysis result explains the faster kinetics of NPX degradation. Additionally, a maximum rate of PhACs degradation was observed when the H2O2 concentration was 5 μM. The degradation of PhACs was strongly inhibited by the presence of tert-butanol when compared to methanol, indicating that the degradation of AAP and NPX was dependent on the presence of OH. Based on the synergistic index and Langmuir-Hinshelwood model, biochar was more efficient for treating PhACs than powdered activated carbon under US irradiation, degrading PhACs mainly via a combination of adsorption onto the absorbents and reaction with OHunder US irradiation with absorbent particles providing nucleation sites. This method shows great potential in providing a viable catalyst toward degrading PhACs within catalytic industrial processes.
AB - This study investigated the degradation of pharmaceuticals (PhACs), acetaminophen (AAP) and naproxen (NPX), via treatment under ultrasonic (US) conditions. The most efficient frequency based on the rate of PhACs degradation and hydrogen peroxide (H2O2) production was found to be 580 kHz when 28, 580, and 1000 kHz frequencies were applied. Additionally, the degradation of PhACs at 580 kHz could be improved by increasing the US-power density and solution temperature. The apparent activation energy of degradation was determined via Arrhenius law to be 10.3 and 11.2 kJ mol-1 for AAP and NPX, respectively, wherein the most favorable degradation pH was acidic. Density functional theory based calculations demonstrated that NPX has 8 barrierless points of reaction compared to AAP having 1 barrierless point. This molecular modeling analysis result explains the faster kinetics of NPX degradation. Additionally, a maximum rate of PhACs degradation was observed when the H2O2 concentration was 5 μM. The degradation of PhACs was strongly inhibited by the presence of tert-butanol when compared to methanol, indicating that the degradation of AAP and NPX was dependent on the presence of OH. Based on the synergistic index and Langmuir-Hinshelwood model, biochar was more efficient for treating PhACs than powdered activated carbon under US irradiation, degrading PhACs mainly via a combination of adsorption onto the absorbents and reaction with OHunder US irradiation with absorbent particles providing nucleation sites. This method shows great potential in providing a viable catalyst toward degrading PhACs within catalytic industrial processes.
KW - Biochar
KW - Molecular modeling
KW - Pharmaceuticals
KW - Powdered activated carbon
KW - Sonolysis
UR - http://www.scopus.com/inward/record.url?scp=84892936296&partnerID=8YFLogxK
U2 - 10.1016/j.seppur.2013.12.021
DO - 10.1016/j.seppur.2013.12.021
M3 - Article
AN - SCOPUS:84892936296
SN - 1383-5866
VL - 123
SP - 96
EP - 105
JO - Separation and Purification Technology
JF - Separation and Purification Technology
ER -