TY - JOUR
T1 - Optimization of naproxen and ibuprofen removal in photolysis using a Box-Behnken design
T2 - Effect of Fe(III), NO 3-, and humic acid
AU - Im, Jong Kwon
AU - Yoon, Yeomin
AU - Zoh, Kyung Duk
PY - 2014/3/21
Y1 - 2014/3/21
N2 - This study investigated the roles and optimum conditions of four independent variables [ultraviolet (UV) intensity, Fe(III), NO3 -, and humic acid (HA) concentration] in the photolytic removal of naproxen (NPX) and ibuprofen (IBP) in water using a response surface method based on the Box-Behnken design. Lab-scale experiments used analysis of variance and t-test statistics to test the significance of independent variables and their interactions. Predicted levels of NPX and IBP removals were found to be in good agreement with experimental levels (R2 = 0.9891 for NPX and 0.9936 for IBP). UV intensity and HA were the most positively and negatively significant variables (P < 0.001), respectively. However, Fe(III) and NO3 - ions had a less significant impact (P > 0.05). This result implies that NPX was removed by both direct photolysis (photons) and indirect reaction (OH radical), while IBP was removed mainly by the OH radical. NPX was more susceptible to the OH radical than IBP (kOH/NPX = 8.24 × 10 9 M-1s-1 and kOH/IBP = 7.51 × 10 9 M-1s-1). According to a quadratic regression model, the predicted maximum removal efficiencies for NPX and IBP were 71.66% and 63.58% when the predicted optimum ratio of UV (mW cm-2):Fe(III) (mg/L):NO3 - (mg/L):HA (mg/L) was 6.3:0.94:0:0 and 6.3:0.94:20:0, respectively, which was similar to the respective experimental NPX and IBP removal values of 70.21% and 62.16%. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of Environmental Science and Health, Part A, to view the supplemental file.
AB - This study investigated the roles and optimum conditions of four independent variables [ultraviolet (UV) intensity, Fe(III), NO3 -, and humic acid (HA) concentration] in the photolytic removal of naproxen (NPX) and ibuprofen (IBP) in water using a response surface method based on the Box-Behnken design. Lab-scale experiments used analysis of variance and t-test statistics to test the significance of independent variables and their interactions. Predicted levels of NPX and IBP removals were found to be in good agreement with experimental levels (R2 = 0.9891 for NPX and 0.9936 for IBP). UV intensity and HA were the most positively and negatively significant variables (P < 0.001), respectively. However, Fe(III) and NO3 - ions had a less significant impact (P > 0.05). This result implies that NPX was removed by both direct photolysis (photons) and indirect reaction (OH radical), while IBP was removed mainly by the OH radical. NPX was more susceptible to the OH radical than IBP (kOH/NPX = 8.24 × 10 9 M-1s-1 and kOH/IBP = 7.51 × 10 9 M-1s-1). According to a quadratic regression model, the predicted maximum removal efficiencies for NPX and IBP were 71.66% and 63.58% when the predicted optimum ratio of UV (mW cm-2):Fe(III) (mg/L):NO3 - (mg/L):HA (mg/L) was 6.3:0.94:0:0 and 6.3:0.94:20:0, respectively, which was similar to the respective experimental NPX and IBP removal values of 70.21% and 62.16%. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of Environmental Science and Health, Part A, to view the supplemental file.
KW - Competition kinetics
KW - OH radical
KW - Pharmaceutical
KW - Photolysis
KW - Response surface methodology
UR - http://www.scopus.com/inward/record.url?scp=84890839854&partnerID=8YFLogxK
U2 - 10.1080/10934529.2014.854670
DO - 10.1080/10934529.2014.854670
M3 - Article
C2 - 24345240
AN - SCOPUS:84890839854
SN - 1093-4529
VL - 49
SP - 422
EP - 433
JO - Journal of Environmental Science and Health - Part A Toxic/Hazardous Substances and Environmental Engineering
JF - Journal of Environmental Science and Health - Part A Toxic/Hazardous Substances and Environmental Engineering
IS - 4
ER -