scholarly journals Enhanced Sulfamerazine Removal via Adsorption–Photocatalysis Using Bi2O3–TiO2/PAC Ternary Nanoparticles

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2273
Author(s):  
Xiaoxuan Zhuang ◽  
Xing Li ◽  
Yanling Yang ◽  
Nan Wang ◽  
Yi Shang ◽  
...  

The presence of sulfonamides (SAs) in water has received increasing attention due to the risk to ecosystems. The adsorption and photocatalysis performance for sulfamerazine (SMZ) of Bi2O3–TiO2 supported on powdered activated carbon (Bi2O3–TiO2/PAC) nanoparticles was evaluated. The amount of doped Bi2O3 not only influenced the photocatalytic performance but also impacted the adsorption capacity. The adsorption mass transfer mechanism of Bi2O3–TiO2/PAC was elucidated and is further discussed in combination with the photocatalytic mechanism. It was indicated that Bi2O3–TiO2/PAC(10%–700 °C) performed best, and the SMZ removal by the adsorption–photocatalysis of Bi2O3–TiO2/PAC(10%–700 °C) reached 95.5%. Adsorption onto active sites was a major adsorption step, and external diffusion was assisted. Superoxide radical (●O2−) and hole (h+) were identified as the major reactive oxygen species (ROS) for SMZ removal. Benzene ring fracture, SO2 extrusion and nitrogenated SMZ were proposed as the main pathways for photocatalysis. Meanwhile, alkaline conditions enhanced photocatalytic performance, while contrary effects were observed for adsorption. The adsorption–photocatalysis removal performance for SMZ in lake water was better than that for river water. It can be generalized for the potential application of photocatalysis coupling with adsorption to remove refractory antibiotics in water.

2018 ◽  
Vol 78 (6) ◽  
pp. 1390-1399 ◽  
Author(s):  
Wenshu Li ◽  
Peng Zhou ◽  
Jing Zhang ◽  
Yongli Zhang ◽  
Gucheng Zhang ◽  
...  

Abstract This study investigated the generation of reactive oxygen species (ROS) (O2−•, H2O2, and HO•) by promoting the Cu(II)/Cu(I) redox cycle with certain reducing agents (RAs) in aerobic aqueous solution, and benzoic acid (BA) was employed as indicator for the hydroxyl radical (HO•). Hydroxylamine (HA) can reduce Cu(II) to Cu(I) to induce chain reactions of copper species resulting in the generation of the superoxide radical (O2−•) and hydrogen peroxide (H2O2), and the intermediate Cu(I) can further activate H2O2 via a Fenton-like reaction to produce HO•, creating the remarkable BA degradation. O2 is indispensable, and unprotonated HA is the motive power in the O2/Cu/HA system. Moreover, pH is a crucial factor of the O2/Cu/HA system due to the protonated HA not being able to reduce Cu(II) into Cu(I). The oxidation of HA can be effectively induced by trace amounts of Cu(II), and both a higher HA dosage and a higher Cu(II) dosage can enhance H2O2 generation and BA degradation. In addition, some other RAs that can reduce Cu(II) into Cu(I) could replace HA in the O2/Cu/HA system to induce the generation of these ROS in aerobic aqueous solution.


2018 ◽  
Vol 5 (12) ◽  
pp. 2864-2875 ◽  
Author(s):  
Qianwu Wang ◽  
Huaxi Zhou ◽  
Xinlei Liu ◽  
Tong Li ◽  
Chuanjia Jiang ◽  
...  

The capability of ZnO nanomaterials to generate reactive oxygen species under solar light, which is critical for their photocatalytic applications and may affect their environmental implications, can be substantially influenced by exposed facets.


RSC Advances ◽  
2020 ◽  
Vol 10 (49) ◽  
pp. 29082-29089
Author(s):  
Wanchao Yu ◽  
Fengjie Chen ◽  
Yarui Wang ◽  
Lixia Zhao

Reactive oxygen species (ROS) play an important role in the photocatalytic degradation of pollutants and are closely related to the surface defects of a semiconductor.


2018 ◽  
Vol 22 (09n10) ◽  
pp. 868-876 ◽  
Author(s):  
Changjun Yang ◽  
Lanchang Gao ◽  
Bingguang Zhang ◽  
Zehui Zhang ◽  
Kejian Deng

A novel strategy for the synthesis of zinc thioporphyrazine nanospheres is presented. The uniform spheres were fabricated through a polymerization reaction without using any template or emulsifier, which result from the covalent links between zinc tetra(2,3-bis(pentenylthio)porphyrazine (ZnPz) possessing eight long flexible chains in periphery and each with one terminal olefin group. A possible mechanism to explain the self-assembly of ZnPz nanospheres was also illuminated through monitoring nanosphere formation by means of transmission electron microscopy (TEM). More importantly, ZnPz nanospheres can effectively activate dioxygen in aqueous media under simulated sunlight irradiation, and showed significantly improved photocatalytic activity for the degradation of Rhodamine B (RhB) as compared to monomeric ZnPz. Furthermore, the reactive oxygen species derived from ZnPz nanospheres under light irradiation were determined by electron paramagnetic resonance (EPR) technology, indicating that singlet oxygen ([Formula: see text]O[Formula: see text] and hydroxyl radical (•OH) are the major reactive oxygen species. The facile synthetic methodology and the enhanced photocatalytic performance of the ZnPz nanospheres endow this novel material with the potential of being an efficient biomimetic photocatalyst for wastewater treatment.


Nanoscale ◽  
2018 ◽  
Vol 10 (15) ◽  
pp. 6971-6980 ◽  
Author(s):  
V. Baldim ◽  
F. Bedioui ◽  
N. Mignet ◽  
I. Margaill ◽  
J.-F. Berret

Cerium oxide nanoparticles are known to catalyze the decomposition of reactive oxygen species such as the superoxide radical and hydrogen peroxide.


Author(s):  
Junye Ma ◽  
Zongsu Wei ◽  
Richard Spinney ◽  
Dionysios D. Dionysiou ◽  
Ruiyang Xiao

The superoxide radical (O2˙−) is an important reactive oxygen species (ROS) in diverse natural aquatic systems and engineered water treatment processes.


2011 ◽  
Vol 57 (5) ◽  
pp. 398-407 ◽  
Author(s):  
A.M. Orshinsky ◽  
G.J. Boland

Hypovirulence in Sclerotinia homoeocarpa is associated with infection by Ophiostoma mitovirus 3a (OMV3a). OMV3a is also present in asymptomatic isolates, with growth and virulence comparable to that of virus-free isolates. Hypovirulent isolates have impaired mitochondrial function resulting in increased activity of the alternative oxidase pathway, which is implicated in the reduction of reactive oxygen species in other fungi. In this study, hypovirulent, asymptomatic, and virus-free isolates were grown on potato dextrose agar amended with ascorbic acid or glutathione and were incubated under various photoperiods to determine the importance of reactive oxygen species, light, and OMV3a infection for differentiation of stromata and apothecia by S. homoeocarpa. Hypovirulent isolates did not form stromata or apothecia. Glutathione and darkness reduced stromata size and apothecia production by virulent and asymptomatic isolates. Apothecia formed under several different photoperiods, and ascorbic acid increased apothecia production. Ascospores were not detected in these apothecia. The results suggest that hypovirulence, light, and the superoxide radical are important factors in the formation of stromata and apothecia by S. homoeocarpa isolates. This is the first report of sterile apothecia production by North American isolates of S. homoeocarpa and provides a starting point for attempts to produce fertile apothecia.


Author(s):  
K. Dvorshchenko ◽  
M. Ashpin ◽  
O. Korotkyi ◽  
Ye. Torgalo ◽  
T. Falalyeyeva

Increase of concentration of pro-inflammatory cytokines (IL-1β, TNF-α) is fixed in blood serum at carrageenan-induced rat paw inflammation, as well as increase of the content of reactive oxygen species (superoxide radical, hydrogen peroxide). At introduction of the preparation on the basis of chondroitin sulfate the level of pro-inflammatory cytokines and reactive oxygen species in blood serum decreases, while the concentration of IL10 increases in 1,7 times concerning the group of animals with сarrageenan-induced inflammation.


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