查找使用阿拉丁产品的科研文献

Peroxymonosulfate enhanced electro-Fenton of sulfamethoxazole removal with ACF/CC@FeOCl-Cu cathode

Yongjun Song,Yi Zhou,Dongli Guo,Yahui Shi,Jiawei Liang,Haoran Li,Dongjin Wan

An innovative ACF/CC@FeOCl-assisted FTEF-SR system was established. • FeOCl-Cu served as catalyst for the electro-Fenton and as a PMS activator. • The primary generated reactive oxygen species were • OH and SO 4 · − ${\text{SO}}_4^{{}^{·-}}$ . • Preferential removal of sulfamethoxazole was achieved in different water matrices. • The system exhibits good stability and energy-saving performance. Sulfamethoxazole (SMX), a representative sulfonamide antibiotic contaminant, poses significant environmental risks. Peroxymonosulfate (PMS) activation-driven electro-Fenton (EF) processes have attracted considerable attention for the removal of organic pollutants from water. In this study, a flow-through heterogeneous EF system integrated with PMS activation (FTEF-SR) was developed using a FeOCl-Cu-modified carbon cloth cathode for the efficient degradation of SMX. The FTEF-SR system exhibited broad pH adaptability and excellent recyclability. Under optimized conditions, near-complete removal of SMX (>99%) was achieved within 60 min. Meanwhile, the effects of catalyst dosage and ratio, current, PMS concentration, electrolyte type, pH, as well as initial concentration were systematically investigated. At a current density of 9 mA cm⁻ 2 and a PMS concentration of 1 mM, SMX and total organic carbon (TOC) removal reached 98.9% (30 min) and 80.2% (180 min), respectively. Moreover, the real-world water matrix and common coexisting ions did not significantly inhibit the removal efficiency of SMX, still maintaining above 92%, indicating that this coupling method was feasible in real application. Quenching experiments and electron paramagnetic resonance (EPR) tests revealed that • OH and SO 4 •– dominated the degradation of SMX in the FTEF-SR system. Overall, this work not only advances the development of efficient and sustainable wastewater purification technologies but also provides valuable mechanistic insights for the degradation of antibiotic contaminants. Download: Download high-res image (478KB) Download: Download full-size image

Magnetic MnFe2O4/MoS2 nanocomposites synthesis for rapid degradation of sulfamethoxazole by activated peroxymonosulfate

Jun Tao,Yanyan Liu,Yaru Li,Xiaoxiao Xie,Li Feng,Shuao Yang,Yuxue Shan

Background Sulfamethoxazole (SMX), as a widely used antibiotic, has been frequently detected in various environments. The accumulation of SMX in water has posed potential risk to the biology and human health. Advanced oxidation technology (AOPs) is an effective method to remove refractory organic pollutants, which has drawn great attention in recent years. Methods Magnetic MnFe 2 O 4 /MoS 2 nanocomposites were synthesized by a two-step hydrothermal method, and characterized with different physicochemical methods. The catalytic performance and mechanism of MnFe 2 O 4 /MoS 2 were studied by the degradation of SMX under peroxisate (PMS) condition. Significant findings The catalytic performance of MnFe 2 O 4 /MoS 2 nanocomposites was superior to that of individual MnFe 2 O 4 or MoS 2 due to the cyclic effect of Fe(II)/Fe(III) and Mn(II)/Mn(III) occurred in the interfaces of MnFe 2 O 4 /MoS 2 . The degradation efficiency of SMX reached 99.1% within 15 min at room temperature, and the catalytic system can maintain a high degradation efficiency in a wide pH range of 3.0 ∼ 9.0. EPR and radical burst experiments showed the main active species of the MnFe 2 O 4 /MoS 2 –3/PMS reaction system were SO 4 •- and • OH radicals. Furthermore, the catalyst exhibits superparamagnetic properties and good stability to enable its recycle and reuse.

Degradation of sulfamethoxazole in microbubble ozonation process: Performance, reaction mechanism and toxicity assessment

Jing Zhang,Shaoyan Lv,Qian Yu,Chun Liu,Junjun Ma,Minglong Jia,Shiyuan Fang

Sulfamethoxazole (SMX) as a widely used antibiotic has caused ecological problems in aquatic environment due to high toxicity and poor biodegradability. In this study, the microbubble ozonation (MB/O 3 ) process was applied for SMX removal, compared with common bubble ozonation (CB/O 3 ) process under the same conditions. The results showed that the SMX degradation and mineralization were much more efficient in MB/O 3 process than those in CB/O 3 process. The enhancement generation of reactive oxygen species (ROS) in MB/O 3 process was proven by electron paramagnetic resonance (EPR) detection, including hydroxyl free radicals ( OH), superoxide free radicals (O 2 − ), and singlet oxygen ( 1 O 2 ). In addition, it was found that OH and 1 O 2 contributed 84.82% and 67.74% of SMX removal in MB/O 3 and CB/O 3 processes, respectively. The preferential reaction sites of SMX were predicted by density functional theory (DFT) calculation in ozonation process. The sulfonamide group, 17(N), 13(C), 15(C), and 9(C) regions were determined as the more active electrophilic reaction sites. More various and complex degradation pathways of SMX in MB/O 3 process were proposed according to intermediates detection and DFT calculation, because both active and inactive sites were found to be attacked due to enhanced ROS oxidation. The more difficult destruction of isoxazole ring than benzene ring in SMX molecule was also observed, especially in CB/O 3 process. The increased toxicity was observed during SMX degradation in both ozonation processes. The toxicity prediction and assessment of SMX and its degradation intermediates showed that many intermediates were more toxic than SMX, due to hydroxyl group addition on benzene ring or isoxazole ring by hydroxylation reaction probably.

Photocatalytically Active Semiconductor Cu3P Unites with Flocculent TiN for Efficient Removal of Sulfamethoxazole

Huancong Shi,Xulei Yao,Shijian Lu,Yuanhui Zuo,Tao Zheng,Liangquan Jia

Sulfamethoxazole is a widely—used antibiotic with high water solubility and low biodegradability, which was considered a refractory environmental pollutant. Hence, a series of functionalized hybrids uniting Cu3P with TiN were prepared. The Cu3P/TiN—x composites remarkably removed the sulfamethoxazole in solution compared with Cu3P and TiN alone. All the as—prepared Cu3P/TiN—x hybrids integrated the advantages of strong adsorption and photocatalysis and achieved removal rates above 70% of sulfamethoxazole. Among the composites, the Cu3P/TiN—2 with a 1:1 molar ratio of Cu: Ti reached a 90% removal rate under dark adsorption for 30 min and subsequent photodegradation for 120 min. The enhanced performance of the Cu3P/TiN—x composites is attributed to the introduced flocculent TiN with a large specific surface area and high conductivity that provide more reactive sites and high electron transferability. Meanwhile, the strong corrosion resistance and chemical stability were also beneficial to the improved performance. Cycling experiments further demonstrate the stability and reliability of the composites. In addition, the capture experiments indicated that the superoxide radical (·O2−) and hydroxyl radical (·OH) played a major role in sulfamethoxazole degradation.Keywords:Cu3P/TiN;plasmonic photocatalyst;sulfamethoxazole;photodegradation

Ascorbic acid promoted sulfamethoxazole degradation in MIL-88B(Fe)/H2O2 Fenton-like system

Xiaolin Han,Nannan Wang,Wei Zhang,Xiaodong Liu,Qi Yu,Juying Lei,Lei Zhou,Guangli Xiu

In this work, the presence of ascorbic acid (AsA) in MIL-88B(Fe) / H 2 O 2 system was demonstrated to significantly increase the sulfamethoxazole (SMX) degradation efficiency. The SMX degradation rate in AsA/MIL-88B(Fe) / H 2 O 2 system was 0.177 L/(mg∙min), which was 60 times that of the MIL-88B(Fe) / H 2 O 2 system. Moreover, the study shows that AsA not only promotes SMX degradation in Fenton-like systems but also expands its pH application range. The effect of coexisting anions on the catalytic performance of the AsA/MIL-88B(Fe) / H 2 O 2 system was also investigated. Then, reactive species were detected via quenching experiments, which indicated •OH as the dominant free radical contributing to SMX degradation. Meanwhile, ESR determinations confirmed the existence of •OH and O2 − • in AsA/MIL-88B(Fe) / H 2 O 2 system. The high activity of the AsA/MIL-88B(Fe) / H 2 O 2 system was attributed to the effective surface Fe(III)/Fe(II) cycle promoted by AsA, and a possible mechanism of the AsA/MIL-88B(Fe) / H 2 O 2 system is proposed. The possible pathways for SMX and AsA degradation in the AsA/MIL-88B(Fe) / H 2 O 2 system are proposed based on the identified intermediates and the ecotoxicity analysis was conducted by ECOSAR . Finally, experimental results using the actual surface water and groundwater revealed the excellent availability of AsA/MIL-88B(Fe)/H 2 O 2 system in remediating SMX contaminated water . This study presents a novel, efficient Fenton-like system using AsA and iron-based metal-organic frameworks for sulfonamide removal from water.

Effect of dissolved silicate on the degradation of sulfamethoxazole by nZVI@D201 nanocomposite

Yaqin Song,Ting Jiang,Jiayu Wu,Jianqiu Chen,Qiong Du

Dissolved silicate (Si), which is omnipresent in natural water and wastewater, is a key factor mediating the separation and transformation of contaminants by forming complexes on the surface of zero-valent iron (ZVI) and iron oxides. In this study, we prepared an nZVI@D201 nanocomposite and studied the redistribution of sulfamethoxazole (SMX) on nZVI@D201 in the pre-equilibration and Si-SMX simultaneous addition systems with 0.1 mM and 1.0 mM Si at an initial pH of 3.0–11.0. The results revealed that both Si pre-equilibration and Si-SMX simultaneous addition exhibited excellent SMX removal efficiency. Si pre-equilibration altered the adsorbed SMX to degradative SMX at an initial pH of 5.0–9.0. Moreover, the simultaneous Si addition at increasing concentrations decreased the degradative SMX. X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy were used to characterize nZVI@D201 after pre-equilibration and simultaneous addition of Si and SMX at an initial pH of 5.0. The results showed that Si pre-equilibration inhibited the transformation of ZVI to magnetite and decreased the crystallinity of the minerals. In addition, the simultaneous addition of Si and SMX impeded the transformation of nZVI to magnetite, whereas the formation of Fe-O-Si complexes hindered the crystallinity. Moreover, scavenger experiments and electron spin resonance tests proved that addition of Si didn’t change the reactive species formation and ·OH was the mainly species for SMX degradation. Based on the detected intermediates via ultra-high performance liquid chromatography-mass spectra, the possible degradation pathways of SMX were proposed.

Effect of bicarbonate on nitrate-induced photosensitive degradation of sulfamethoxazole under UV irradiation

Yiqing Liu,Shixiang Wang,Dongbin Fu,Yongsheng Fu

Functionally-Designed Chitosan-based hydrogel beads for adsorption of sulfamethoxazole with light regeneration

Aijiao Zhou,Kai Yang,Xumeng Wu,Guoqing Liu,Tian C. Zhang,Qin Wang,Fan Luo

Adsorption method has been widely used in the removal of emerging contaminants. However, many adsorbents are puzzled by key obstacles for effective and simple regeneration. In this work, the functionally-designed graphitic carbon nitride (g-C 3 N 4 ) embedded chitosan-polyvinyl alcohol composite (g-C 3 N 4 /CS/PVA) hydrogel beads were synthesized for the adsorptive removal of sulfamethoxazole (SMX) from water, and they could be regenerated by light. The adsorption kinetics, isotherm, thermodynamics, and impacting factors were systematically investigated. And the adsorption capacity of the hydrogel for SMX was relatively stable at pH of 4–8, with the maximum adsorption capacities being 5.8 mg g −1 at pH 5. The main adsorption force may be inferred to the electrostatic interactions between SMX and hydrogel beads, and hydrogen bonds between the amino or hydroxyl groups of the hydrogel and the amino of the SMX. The dominance of electrostatic interactions resulted in SMX adsorption being highly dependent on ionic strength. Being irradiated with an ultraviolet lamp for 5 recycles, the hydrogel beads still kept good adsorption capacity. The regeneration behavior was attributed to the photocatalytic degradation of SMX by g-C 3 N 4 . Namely, photocatalytic oxidation reactivated the adsorption sites and increased the release of adsorbed pollutants with improved desorption performance.

Sulfamethoxazole degradation by Pseudomonas silesiensis F6a isolated from bioelectrochemical technology-integrated constructed wetlands

Xiaohui Liu,Jing Chen,Ying Liu,Zhengfen Wan,Xiaochun Guo,Shaoyong Lu,Dongru Qiu

The antibiotic-degrading ability and mechanism of the bacteria in the novel and ecological bioelectrochemical technology-integrated constructed wetlands (BICW) remain unknown. In this study, the sulfamethoxazole (SMX) degrading strain Pseudomonas silesiensis F6a (F6a), which had high degradation efficiency, was firstly isolated from a substrate sample in BICW. The SMX degradation process of F6a follows pseudo first order kinetics. Four metabolic pathways and twelve degradation products were identified. Based on genomics and proteomics analysis, six key SMX-degrading genes, Gene4641 deoC , Gene0552 narI , Gene0546 luxS , Gene1753 nuoH , Gene0655 and Gene4650, were identified, which were mainly participated in C-S cleavage, S-N hydrolysis and isoxazole ring cleavage. Interestingly, we found the corresponding sulfonamides resistance genes were not detected in F6a, which may provide an evidence for low abundance of the sulfonamides resistance genes in BICW system. These findings would contribute to a better understanding of biotransformation of antibiotic in the BICW.

Activation of peracetic acid by RuO2/MWCNTs to degrade sulfamethoxazole at neutral condition

Yajie Qian,Jinjing Huang,Jiabin Chen,Gang Xue,Zilin Zhou,Pin Gao

Peracetic acid (PAA) as an emerging disinfectant has raised extensive concern due to its high oxidation capacity and low byproducts formation potential. In this work, RuO 2 supported multi-walled carbon nanotube (MWCNTs) was synthesized and applied to activate PAA to degrade sulfamethoxazole (SMX). PAA could be effectively activated by RuO 2 /MWCNTs (RM). Increasing RM loadings (0.03–0.3 g/L) or PAA dosages (0.25–1.5 mM) generally enhanced the degradation efficiency, the excellent performance in SMX degradation (100%) was achieved at 1 mM PAA, 0.2 g/L RM and neutral conditions. Electron paramagnetic resonance (EPR) techniques and radical scavenging experiments indicated acetylperoxy radical (CH 3 C(O)OO·) and acetoxyl radical (CH 3 C(O)O·) as the major reactive radicals responsible for SMX degradation. X-ray photoelectron spectroscopy (XPS) analysis indicated that the electron transfer of ≡Ru 3+ /≡Ru 4+ involved in the PAA activation. The effect of water matrices was also investigated, HCO 3 – and natural organic matter (NOM) slightly inhibited SMX degradation, while Cl - had little impact on SMX degradation. For the reusability of RM, the SMX removal was still achieved 90% after three consecutive tests. This work provides the potential application of RM/PAA in destructing emerging pollutants.

Multiple roles of humic acid in the photolysis of sulfamethoxazole: kinetics and mechanism

Li-Jing Chen,Chao Song,Zhi-Chen Yang,Hai-Yan Fu,Chang Xu,Xiao-Min Sun,Shu-Guang Wang

Photolysis is considered to be an important elimination process for antibiotics in nature. Humic acids (HA) are ubiquitous in aquatic environments and inevitably encounter antibiotics, which may interfere with their photolysis and thus alter their environmental fate. In this study, we chose sulfamethoxazole (SMX) as a typical antibiotic to assess the effect of HA on photolysis. HA at 1 mg L−1 greatly promoted the photolysis of SMX by 98.8%. However, high-concentration HA inhibited the photolysis, and the photolysis rate decreased by 92.9% in the presence of 100 mg L−1 HA. Furthermore, HA exhibited different effects on direct and indirect photolysis. Low-concentration HA induced the production of ˙OH to promote indirect photolysis, whereas high-concentration HA could compete with SMX for photons and decrease light penetration via light shielding to inhibit direct photolysis greatly. Based on density functional theory (DFT) calculation, the Na site in HA could bind with the N–O and –SO2–NH– on the isoxazole ring of SMX to form complexes. The active sites of SMX and SMX–HA complexes were also identified, and the active sites increased after complexation. Moreover, low-concentration HA exhibited little influence on the degradation pathway of SMX due to little complexation degree while SMX was degraded via different paths in the presence of high-concentration HA, which was mainly attributed to the complexation of SMX and HA. Besides, the toxicity of most intermediates were lower than that of SMX, but some intermediates in new degradation pathways tended to accumulate during photolysis, resulting in higher potential environmental risk.

Effect of biochar-derived dissolved organic matter on adsorption of sulfamethoxazole and chloramphenicol

Fang Yang,Qi Zhang,Hongxian Jian,Cuiping Wang,Baoshan Xing,Hongwen Sun,Yueli Hao

Biochar-derived dissolved organic matter (DOM) plays a crucial role in controlling the interactions between pollutants and biochars. Here, we determined the compositions of DOMs extracting from biochars (BCs) and acid-modified-biochars (MBCs) at different pH using UV, 3D-fluorescence and ultra-high-resolution mass spectroscopy (ESI-FTICR MS), which allowed us, for the first time, to distinguish the effect of DOM from biochars on sulfamethoxazole (SMX) and chloramphenicol (CAP) adsorbed onto biochars. The detailed results showed DOM shortened SMX and CAP adsorption equilibrium time, and more DOM increased SMX adsorbed, while inhibit CAP adsorbed onto biochar. Low-temperature biochar with a high extracting solution pH could release more DOM, and the polarity index of DOM was opposite with corresponding biochar. The correlation between the polarity of biochar and adsorption capacity was opposite to the correlation between the DOM released from corresponding biochars and adsorption capacity. Moreover, we found the fulvic and humic acid-like of DOMs inhibited biochar adsorption for SMX, however, the more compounds fulvic and humic acid-like of DOMs and C c H h O o N n S s molecular structure would promote biochar adsorption of CAP. This study demonstrates the potential of DOM as a new mechanism in adsorption and remediation studies but also reveals challenges for the future application of biochar.