Photodegradation of sulfonamide antimicrobial compounds (sulfadiazine, sulfamethizole, sulfamethoxazole and sulfathiazole) in various UV/oxidant systems

2015 ◽  
Vol 71 (3) ◽  
pp. 412-417 ◽  
Author(s):  
J. T. Wu ◽  
C. H. Wu ◽  
C. Y. Liu ◽  
W. J. Huang

This study used Na2S2O8, NaBrO8 and H2O2 to degrade sulfadiazine (SDZ), sulfamethizole (SFZ), sulfamethoxazole (SMX) and sulfathiazole (STZ) under ultraviolet (UV) irradiation. The initial concentration of sulfonamide and oxidant in all experiments was 20 mg/L and 5 mM, respectively. The degradation rate for sulfonamides satisfies pseudo-first-order kinetics in all UV/oxidant systems. The highest degradation rate for SDZ, SFZ, SMX and STZ was in the UV/Na2S2O8, UV/NaBrO3, UV/Na2S2O8 and UV/H2O2 system, respectively. In the UV/Na2S2O8 system, the photodegradation rate of SDZ, SFZ, SMX and STZ was 0.0245 min−1, 0.0096 min−1, 0.0283 min−1 and 0.0141 min−1, respectively; moreover, for the total organic carbon removal rate for SDZ, SFZ, SMX and STZ it was 0.0057 min−1, 0.0081 min−1, 0.0130 min−1 and 0.0106 min−1, respectively. Experimental results indicate that the ability of oxidants to degrade sulfonamide varied with pollutant type. Moreover, UV/Na2S2O8 had the highest mineralization rate for all tested sulfonamides.

Author(s):  
T. H. Ho ◽  
C. H. Wu ◽  
T. Y. Han ◽  
W. J. Syu

Abstract Ozone, UV/ozone, ozone/persulfate (PS) and UV/ozone/PS systems were used to mineralize sulfonamides. Sulfadiazine (SDZ), sulfamerazine (SMR) and sulfamethazine (SMZ) were the target compounds. The novel contribution of this study is its determination of the effects of PS addition, sulfonamide structure, pH and salinity on sulfonamide mineralization in ozone-based systems. The mineralization rate of sulfonamides satisfied pseudo-first-order kinetics. The SMZ mineralization rate constant in ozone, UV/ozone, ozone/PS and UV/ozone/PS systems at pH 5 were 0.0058; 0.0101; 0.0069 and 0.0802 min−1, respectively, and those at pH 7 were 0.0075; 0.0116; 0.0083 and 0.0873 min−1, respectively. The increase in the number of methyl-substituents in the heterocyclic group of SMZ and the corresponding increase in the steric hindrance of radical addition, reduced mineralization rates below those of SMR and SDZ. The addition of PS promoted sulfonamide mineralization in the ozone-based systems; conversely, salinity inhibited sulfonamide mineralization.


2013 ◽  
Vol 67 (7) ◽  
pp. 1605-1611 ◽  
Author(s):  
Qian Zhao ◽  
Li Feng ◽  
Xiang Cheng ◽  
Chao Chen ◽  
Liqiu Zhang

This paper investigated the effects of selected common chemical species in natural waters (HCO3−, NO3− and humic acids (HA)) on the photodegradation of amoxicillin (AMO) under simulated irradiation using a 300 W xenon lamp. Quenching experiments were carried out to explore the mechanisms of AMO photodegradation. The results indicated that AMO photodegradation followed pseudo-first-order kinetics. Increasing AMO concentration from 100 to 1,000 μg L−1 led to the decrease in the photodegradation rate constant from 0.2411 to 0.1912 min−1. The presence of NO3− and HA obviously inhibited the photodegradation rate of AMO because they can compete for photons with AMO. Bicarbonate, as a hydroxyl radical (·OH) scavenger, also adversely affected AMO photodegradation. Quenching experiments in pure water suggested that AMO could undergo self-sensitized photooxidation via ·OH and singlet oxygen (1O2), accounting for AMO removal of 34.86 and 8.26%, respectively. In HA solutions, the indirect photodegradation of AMO was mostly attributed to the produced ·OH (22.37%), 1O2 (24.12%) and 3HA* (20.80%), whereas the contribution of direct photodegradation was to some extent decreased.


2012 ◽  
Vol 441 ◽  
pp. 549-554
Author(s):  
Ying Jie Cai ◽  
Xiao Jun Yang ◽  
Dong Sheng Xia ◽  
Qing Fu Zeng

Abstract. Degradation of reactive brilliant red X-3B (X-3B) by a UV/Mn2+/H2O2/micro- aeration method was investigated. The influencing factors of degradation of X-3B including UV irradiation, aeration, pH value, H2O2 concentration and X-3B concentration were examined. The results show that X-3B was effectively degraded by the UV/Mn2+/H2O2/micro-aeration method. The degradation rate of X-3B was obtained from weighted linear least squares analysis of the experimental data, and accorded with the pseudo-first order kinetics equation.


2014 ◽  
Vol 68 (1) ◽  
Author(s):  
Petruta Oancea ◽  
Viorica Meltzer

AbstractIn the present work, kinetics of tartrazine decay by UV irradiation and H2O2 photolysis, and the removal of total organic carbon (TOC) under specific experimental conditions was explored. Irradiation experiments were carried out using a photoreactor of original design with a low-pressure Hg vapour lamp. The photodegradation rate of tartrazine was optimised with respect to the H2O2 concentration and temperature for the constant dye concentration of 1.035 × 10−5 M. Tartrazine degradation and the removal of TOC followed the pseudo-first-order kinetics. The much higher k obs value for tartrazine degradation (7.91 × 10−4 s−1) as compared with the TOC removal (2.3 × 10−4 s−1) confirmed the presence of reaction intermediates in the solution.


2010 ◽  
Vol 113-116 ◽  
pp. 176-180 ◽  
Author(s):  
Meng Li ◽  
Dong Lei Zou ◽  
Hao Chen Zou ◽  
Dong Yan Fan

Using iron filings, activated carbon power and clay as raw materials, the granular iron-carbon micro-electrolysis packing was made by the method of calcination. The influence of initial chlorobenzene (CB) concentration, pH value and reaction temperature on the removal rate of simulated wastewater containing CB were investigated. The results showed that the reaction followed the pseudo-first-order kinetics model and the rate constants varied at a relatively low degree at various pH. Temperature is an important parameter and an increase in temperature could significantly raise the reaction rates. The column packed with packing was designed to remove CB in wastewater. After running for 70 days, the packing still had good performance and there was no obvious decrease on the removal rate.


2014 ◽  
Vol 70 (8) ◽  
pp. 1428-1433 ◽  
Author(s):  
C. Y. Kuo ◽  
C. H. Wu ◽  
J. T. Wu ◽  
Y. C. Chen

This study produced immobilized Cu2O via microwave irradiation. The surface properties of Cu2O were assessed by X-ray diffraction, scanning electron microscopy, and UV–vis spectroscopy. The catalytic activity of the generated Cu2O was examined for bisphenol (BPA) degradation in Cu2O/H2O2 and visible-light/Cu2O/H2O2 systems under various H2O2 concentrations. Cu2O can decompose H2O2 to generate radicals, similar to the Fenton-like process. The BPA degradation rate followed pseudo-first-order kinetics. The optimal H2O2 concentration was 30 mM and the BPA degradation rate under 30 mM H2O2 in the Cu2O/H2O2 and visible-light/Cu2O/H2O2 systems was 1.43 and 2.69 h−1, respectively. The original Cu2O partly oxidized into CuO in the visible-light/Cu2O/H2O2 system and the BPA degradation percentage declined to 51% from 100% after the fifth cycle.


2014 ◽  
Vol 595 ◽  
pp. 14-18
Author(s):  
Chao Yin Kuo ◽  
Hung Min Hsiao ◽  
Xiang Ren Lin

Degradation of aqueous bisphenol A (BPA) using photocatalysts of granular iodine doped titanium dioxide (I-doped TiO2) under various irradiations (365 or 410 nm) was investigated. The degradation effect of aqueous BPA using I-doped TiO2 photocatalysts (iodine/titanium = 0.5 mole %) were 93 and 100 % under two irradiations of visible and UV light. This result indicated that I-doped TiO2 photocatalysts of were achieving energy-saving. In addition, the BPA removal rate satisfies pseudo-first-order kinetics and the degradation of BPA was evident after five cycles, indicating the stability and reusability.


2020 ◽  
Vol 82 (11) ◽  
pp. 2425-2431
Author(s):  
A. M. Wang ◽  
C. H. Wu ◽  
E. H. Huang

Abstract This study investigates the removal of sulfamethizole (SFZ) in ozone (O3), O3/Na2S2O8 (sodium persulfate), UV/Na2S2O8, UV/O3, and UV/O3/Na2S2O8 systems. The effects of pH and salinity on SFZ mineralization were evaluated. The mineralization of SFZ followed pseudo-first-order kinetics. At pH 5, the rate constants of SFZ mineralization in O3, O3/Na2S2O8, UV/Na2S2O8, UV/O3, and UV/O3/Na2S2O8 systems were 0.576, 0.924, 0.702, 1.26, and 5.21 h−1, respectively. The SFZ mineralization rate followed the order pH 5 > pH 7 > pH 9 in all tested advanced oxidation processes. Salinity increased the rate of SFZ mineralization in O3 and O3/Na2S2O8 systems and decelerated it in UV/Na2S2O8, UV/O3, and UV/O3/Na2S2O8 systems. UV/O3/Na2S2O8 was the best system for mineralizing SFZ, and sulfate radicals were the predominant species in UV/O3/Na2S2O8.


2019 ◽  
Vol 79 (11) ◽  
pp. 2195-2202
Author(s):  
Jie Yao ◽  
Jinglin Guo ◽  
Zhaoguang Yang ◽  
Haipu Li ◽  
Bo Qiu

Abstract The monoterpene alcohol α-terpineol is extensively used as the foaming agent in mineral processing and can be released to environment along with the wastewater. This study evaluated the feasibility of eliminating α-terpineol in water by ultraviolet irradiation (UV) in combination with hydrogen peroxide (H2O2). Within an H2O2 dose of 10 mg/L and an UV fluence of 64.8 J/cm2, more than 95% of the α-terpineol can be removed. The reactions fitted well to pseudo-first-order kinetics, and the apparent rate constant was 0.0678 min−1. The effects of matrix species including various anions and humic acid (HA), were evaluated. The degradation rate decreased significantly with the addition of bicarbonate and HA. Further verification was carried out with three types of real water samples. In the ground water and the surface water, the degradation rate decreased likely due to the presence of natural organic matter. Finally, possible degradation pathways were proposed based on the identification of transformation products, and the occurrence of two main transformation products were monitored. This study demonstrated that the UV/H2O2 is an effective technology for the degradation of α-terpineol in water.


Author(s):  
Soraya Boukhedoua ◽  
Razika Zouaghi ◽  
Oualida Nour El Houda Kaabeche

Abstract In the present work, a comparative study of the photooxidation of an aqueous solution of Methyl Orange (MeO) has been realized using H2O2 and IO3 −, BrO3 −, ClO3 −, ClO4 −, BO3 − ions in the presence of UV low pressure mercury lamp (UV-C light at λ max = 254 nm). The initial concentration of MeO in all experiments was 6 × 10−5 mol L−1. The degradation rate of MeO follows pseudo-first-order kinetics in all UV/Oxidant systems. The highest degradation rate of MeO was in the BrO3 −/UV254nm system. Different systems were compared for an oxidant concentration of 10−2 mol L−1 and the obtained results showed that decolorization followed the decreasing order: BrO 3 − /UV 254 nm  > IO 3 − /UV 254 nm  > H 2 O 2 /UV 254 nm  > BO 3 − /UV 254 nm  > ClO 3 − /UV 254 nm  = ClO 4 − /UV 254 nm  = UV 254 nm . The optimization of oxidants concentration for each process was determined (10−2 mol L−1 for IO3 − which gives almost the same k app for 5 × 10−3, 10−2 mol L−1 for BO3 − and 5 × 10−2 mol L−1 for H2O2). No degradation of MeO in presence of ClO3 − and ClO4 − because these ions do not absorb at 254 nm, therefore they do not generate radical species which degrade organic pollutants. The mineralization was also studied where it was reached 97% after 5 h of irradiation for both H2O2/UV254 nm and BO3 −/UV254 nm systems.


Sign in / Sign up

Export Citation Format

Share Document