ENVIRONMENT INTERNATIONAL
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2022
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IF 13.352
Yurong Gu,Zi Song,Zijun Dong,Feiyun Sun,Chengchun Jiang,Jikun Qi
Iopamidol (IPM) is widely used in medical clinical examination and treatment and has immeasurable harm to the ecological environment. The combination of UV and sulfite (UV/sulfite) process was developed to degrade IPM in this study. In contrast to that almost no removal of IPM was observed under sulfite reduction alone, the UV/sulfite process could efficiently reductively degrade IPM with the observed rate constant (k obs ) of 2.08 min −1 , which was nearly 4 times that of UV irradiation alone. The major active species in the UV/sulfite process were identified as hydrated electrons (e aq - ) by employing active species scavengers. The influence of the initial pH, sulfite dosage, IPM concentration, UV intensity and common water matrix were evaluated. The degradation of IPM reached nearly 100% within only 2.5 min at pH 9, and k obs increased at higher initial sulfite dosages and greater UV intensities. HCO 3 – had a limited effect on the degradation of IPM, while humic acid (HA) was found to be a strong inhibitor in the UV/sulfite process. With the synergistic action of UV/sulfite, most of the iodine in IPM was found to release in the form of iodide ions (up to approximately 98%), and a few formed iodide-containing organic compounds, reducing significantly the toxicity of degradation products. Under direct UV irradiation and free radical reduction (mainly e aq - ), 15 transformation intermediates of IPM were produced by amide hydrolysis, deiodination, hydroxyl radical addition and hydrogen abstraction reactions, in which free radical attack accounted for the main part. Consequently, the UV/sulfite process has a strong potential for IPM degradation in aquatic environments.
研究领域:
环境科学
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医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Jing Liu,Huiyu Dong,Carmen Sans,Xiangjuan Yuan
In this study, a series of boron (B) and oxygen (O) dual doped g-C 3 N 4 (BOCNx) composites with different boric acid dopant dosages were successfully synthesized through one-step thermal condensation method. Amongst, BOCN50 exhibited the best catalytic ozonation activity, achieving 97 % of iopamidol (IPM) degradation within 15 min and the highest k value (0.3166 min −1 ), which was 8 times higher than that of ozonation alone. Multiple characteristic techniques were used to explore the surface properties of BOCNx catalysts and it was found that B and O primarily coordinated in g-C 3 N 4 as the forms of C-O, C = O and B-N bonds. Further investigation in the structure–activity relationship of BOCNx catalyst indicated that the increasing contents of oxygen-containing functional groups and B-N bonds were linearly correlated with the IPM degradation rate. The results of scavenger experiments and ESR analysis demonstrated that the main reactive oxygen species involved were hydroxyl radicals, superoxide radicals, and singlet oxygen ( • OH, • O 2 − and 1 O 2 ). Additionally, up to 12 intermediate products of IPM during the reaction were detected, and the corresponding degradation pathways were elucidated. Finally, the structure of BOCN and the active sites for O 3 adsorption were determined by density functional theory (DFT) calculation, thus providing theoretical support for studying the mechanism of catalytic ozonation degradation.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Ruijie Teng,Hong Wei,Jinfen Niu,Xia Ma
The activation of peroxymonosulfate (PMS) with FeS is a promising wastewater treatment technology. The degradation mechanism of iopamidol (IPM) in the PMS/FeS system and the effect of Cl − were examined. The results indicated that the surface-bound radicals (SO 4 •− ads and HO • ads ) generated on the FeS surface were identified as the primary reactive species contributing to IPM degradation. The surface and dissolved Fe(II), together with the Fe(II)/Fe(III) cycling facilitated by the surface sulfur on FeS, were all conducive to the activation PMS. When Cl − were in the range of 1 ∼ 5 mmol/L, the IPM degradation rate remained at almost 80 %. The generation of chlorinated products reduces ecotoxicity. The presence of Cl − mitigated the formation of iodoform, notwithstanding the impact on TOC removal. This study can provide a certain basis for the mechanism of FeS/PMS in degrading contaminants and its application for contaminant removal from chlorinated waters.
研究领域:
环境科学
·
水处理技术
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Dexin Wu,Feng Yang,Di Zhao,Lulu Zhu,Ruiqi Wang,Jun Hu,Zhimin Qiang,Weiting Yu,Yuanchen Chen
The joint disinfection of monochloramine (MCA) and peroxymonosulfate (PMS) can combine the advantages of both sides; and the iodine-containing micropollutants are widely present in drinking water. For the first time, the conversion of iopamidol (IPM) was investigated in the MCA/PMS system. For IPM degradation, the observed pseudo-first-order rate constant ( k obs ) was 0.0076 min −1 , and the apparent rate constant ( k app ) was 6.14 × 10 −7 μM −2.16 min −1 . The reaction orders for MCA ( m ) and PMS ( n ) were fitted to be 1.14 and 1.02, respectively. The mutual activation of MCA and PMS was a base-catalyzed reaction, which was highly exothermic and thermodynamically favored with a free energy of − 78.74 kcal/mol. It is believed that Cl • and 1 O 2 contributed to IPM degradation. The k obs value was increased by an alkaline pH and the presence of Cl − , while reduced by the existence of NOM, HCO 3 − and NH 4 + . The N in MCA was converted to NH 4 + -N, NO 2 − -N and NO 3 − -N, and 47.0 % of I in IPM was converted to IO 3 − . In the MCA/PMS system, IPM transformation was mainly via amide hydrolysis, deiodination and substitution reaction by reactive species. The study provides an insight into the fate of iodine-containing micropollutants during the joint disinfection of MCA and PMS.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2020
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IF 9.038
Jun Hu,Hao Chen,Huiyu Dong,Lulu Zhu,Zhimin Qiang,Jianming Yu
ABSTRACT Cast iron pipes are commonly applied in drinking water distribution systems (DWDSs); peroxymonosulfate (PMS) is a promising alternative for drinking water disinfection; organic micropollutants is still present in drinking water after waterworks’ treatment. However, iron corrosion products may affect the reactions between a disinfectant and organic micropollutants. The study investigated the transformation of iopamidol (IPM) and atrazine (ATZ) by PMS under the catalysis of a composite iron corrosion product (Fe/Fe 3 O 4 ). The pseudo-first-order rate constants ( k ) for the degradation of IPM and ATZ were 1.47 and 1.03 min –1 , respectively. Electron paramagnetic resonance (EPR) experiments indicated that PMS was effectively activated to yield sulfate radical (SO 4 •− ) and hydroxyl radical (HO • ), mainly via the reduction by Fe component, dissolved Fe 2+ and generated F eocta 2 + . SO 4 •− contributed more than HO • to the degradation of IPM and ATZ, and the radical yield achieved 0.97 mol/mol. The k values reached maximum with Fe/Fe 3 O 4 and PMS doses of 2.5 g L –1 and 25 mg L –1 , respectively. The optimum mass fraction of Fe 3 O 4 in Fe/Fe 3 O 4 (MF mag ) and pH were 10% and 7.0, respectively. The k values increased with increasing temperature, while decreased in the presence of water matrix. Most of the iodine released from IPM was oxidized to IO 3 − , and NH 4 + was the dominant species of nitrogen released from ATZ. The identification of transformation intermediates showed that the radical chain reactions of IPM was mainly initiated from single electron transfer and radical adduct formation, while those of ATZ was primarily initiated from hydrogen atom abstraction and radical adduct formation.
研究领域:
环境科学
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化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
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2020
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IF 9.13
Ying Cao,Wei Qiu,Juan Li,Yumeng Zhao,Jin Jiang,Suyan Pang
UV/sulfite process in the absence of oxygen was previously applied as an advanced reduction process for the removal of many halogenated organics and inorganics in water and wastewater. Here, it was found that UV/sulfite process in the presence of oxygen could act as an advanced oxidation process. Specifically, the oxysulfur radicals (including sulfate radical ( SO 4 · − ) and sulfite/peroxomonosulfate radicals ( SO 3 · − / SO 5 · − )) played important roles on the degradation of iopamidol (IPM) as a typical iodinated contrast media (ICM). Furthermore, the contribution of SO 4 · − on IPM removal gradually increased as pH increased from 5 to 7 and that of SO 3 · − / SO 5 · − decreased. Besides, all water quality parameters (i.e., chloride (Cl − ), iodide (I − ) and natural organic matter (NOM)) investigated here exhibited inhibitory effect on IPM removal. Three inorganic iodine species (i.e., I − , reactive iodine species and iodate (IO 3 − )) were detected in UV/sulfite process in the presence of oxygen, while only I − was detected in that without oxygen. During UV/sulfite/ethanol, UV photolysis and UV/peroxydisulfate (PDS)/ tert -butyl alcohol (TBA) processes, thirteen transformation products including eleven deiodinated products of IPM were identified by ultra HPLC quadrupole time of flight-mass spectrometry (UPLC-Q-TOF-MS). Besides, these products generated by direct UV photolysis, SO 4 · − and SO 3 · − / SO 5 · − were further distinguished. The acute toxicity assay of Vibrio fischeri indicated that transformation products by UV/sulfite under aerobic conditions were less toxic than that by direct UV photolysis.
研究领域:
环境科学
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化学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
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IF 6.735
Ze-Chen Gao,Yi-Li Lin,Bin Xu,Ying Xia,Chen-Yan Hu,Tong-Cheng Cao,Xiang-Yun Zou,Nai-Yun Gao
This study revealed the iopamidol degradation performance and the synergistic effect of dual-wavelength ultraviolet light-emitting diodes (UV-LEDs). It was found that the dual-wavelength irradiation (265 and 280 nm) can promote iopamidol degradation during both UV-LED alone and UV-LED/chlorine processes ( p < 0.05). The effects of key experimental parameters including pH, chlorine dosage and water matrix during UV-LED/chlorine process were evaluated. Peak degradation rate was observed at pH 7.0 due to the combined effects of the quantum yield of aquatic chlorine photolysis (Φ chlorine ) and absorptivity of chlorine. The destruction pathways of iopamidol in the UV-LED/chlorine process were proposed by Ultra Performance Liquid Chromatography-Electrospray Ionization-mass spectrometry. Additionally, an opposite trend of iodinated trihalomethane (I-THM) formation during subsequent chlorination between Milli-Q and real waters with prolonging irradiation time was observed, while other detected disinfection by-product (DBP) formation showed the same variation in Milli-Q and real waters. The UV-LED/chlorine treatment using dual-wavelength can enhance iopamidol degradation significantly, but it also promoted I-THM formation in real water, indicating the need for evaluating DBPs before the application of UV-LED/chlorine process in drinking water treatment.
研究领域:
环境科学
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水处理工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2021
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IF 10.588
Yuan Gao,Wenxia Fan,Zhong Zhang,Yang Zhou,Zhu Zeng,Kai Yan,Jun Ma,Khalil Hanna
Although the ability of iron/sulfite system for decontamination purposes has been investigated, the complex reactive species generated and the underlying transformation mechanisms remain elusive. Here, we have comprehensively examined the transformation of iopamidol (IPM), a representative of iodinated X-ray contrast media, by iron catalyzed sulfite oxidation process under different water chemistry conditions. Multiple reactive intermediates including Fe(IV), SO 4 •− , and SO 5 •− were identified by conducting a series of experiments. Eight transformation products were detected by mass spectrometry analysis, and correlation with the nature of involved reactive species has been made. Further, the transformation pathways including amide hydrolysis, deiodination, amino and hydroxyl groups oxidation were proposed. Interestingly, these transformation products could be removed through adsorption to iron precipitates formed via pH adjustment. Combining Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, we revealed an effective way to reduce the amount of transformation products in the treated solutions. Since the iron/sulfite process appears to be less sensitive to natural organic matter, it exhibited very good efficiency for IPM removal in real water samples, even with a high organic carbon loading. These findings may have strong implications in the development of novel oxidation process based on the sulfite/iron systems for wastewater treatment .
研究领域:
环境科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2022
·
IF 11.072
Weiqiang Wang,Zhonglin Chen,Pengwei Yan,Bingyuan Wang,Yabin Li,Jing Kang,Jimin Shen,Yizhen Cheng,Shuyu Wang,Yue Liu,Zhe Wang,Xueyan Li
Iopamidol (IPM) was frequently detected in drinking water and effluents from wastewater treatment plants (WWTPs). A silicate-based microfiltration membrane (SFM) was successfully synthesized using silicate cement as raw material and pore-forming agent. In this study, peroxymonosulfate (PMS) was activated by SFM for the first time to effectively degrade and mineralize IPM. The removal efficiency and mineralization rate of IPM were 99.7% and 49.5% respectively within 30 min in the SFM/PMS process, which were higher than those obtained by PMS oxidation only (12.8% and 1.26%) and SFM adsorption (negligible). The effects of solution pH, PMS dosage, reaction temperature, natural organic matter (NOM), chloride ion (Cl − ), bicarbonate (HCO− 3), and water matrixes on the degradation of IPM were systematically evaluated. Based on radical inhibition examinations and X-ray photoelectron spectroscopy (XPS) analysis, the potential activation mechanism was elucidated. It was found that the Fe(II) and alkaline hydration products on the surface of SFM could promote the activation of PMS. Radical scavenging tests and electron spin resonance (ESR) experiments suggested that hydroxyl radicals ( • OH), sulfate radicals ( S O 4 · − ), singlet oxygen ( 1 O 2 ) and superoxide radicals ( O 2 · − ) generated in SFM/PMS system played a critical role for IPM degradation. Finally, eleven intermediates in the degradation process of IPM were identified and five degradation pathways were proposed, mainly including hydroxyl oxidation, amide hydrolysis, amino oxidation, hydroxyl substitution and dehydroxylation . The results show that the SFM/PMS process with its excellent catalytic activity is a promising strategy for effectively removing and mineralizing organic contaminants .
研究领域:
环境科学
·
水处理技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Jun Hu,Ruiqi Wang,Shangkun Li,Jun Wu,Zhimin Qiang
Peroxymonosulfate (PMS) is an alternative disinfectant for drinking water . This study aimed to investigate the transformation of iopamidol (IPM) catalyzed by a main copper corrosion product ( c -Cu 2 O) with PMS as a disinfectant. The observed pseudo-first-order constant ( k obs ) for the IPM degradation in the c -Cu 2 O/PMS system (0.033 min −1 ) was 3 times that in the CuO/PMS system (0.011 min −1 ). The quenching tests and the electron paramagnetic resonance (EPR) experiments indicate that O 2 •− and 1 O 2 contributed to IPM degradation in the c -Cu 2 O/ PMS system. The complexation of metastable Cu(II) with a PMS molecule polarized the O O bond and then facilitated the electron transfer from the PMS molecule to other PMS and O 2 molecules, which directly and indirectly promoted the yield of O 2 •− and 1 O 2 . The iodine balance indicated that 26.0% of initial TOI was converted to IO 3 − , and CHI 3 only accounted for 0.6% of the residual TOI. In the c -Cu 2 O/PMS system, IPM conversion was started with amide C−N bond breakage, deiodination reaction and hydrogen abstraction. This study helps to better understand the conversion mechanisms of iodine-containing organic micropollutants when PMS is deployed as a disinfectant in copper pipes.
研究领域:
环境科学
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化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Wen Xu,Shiwen Dong,Haijun Cheng,Stefanos Giannakis,Xiaohui Lu,Zhiqiao He,Da Wang,Shuang Song,Jun Ma
Mixed refractory organic wastewater containing both organic molecular and nanoparticle contrast agents poses a significant challenge for wastewater treatment. In this study, heterogeneous catalytic ozonation (HCO) technology was employed, creatively using the nanoparticle contrast agent Mn 3 O 4 /SiO 2 /C as a catalyst for the degradation of the organic molecular contrast agent iopamidol (IPM). This study aims to provide new insights and approaches to address the challenge of mixed contrast agent treatment in medical wastewater through a “treat-waste-with-waste” strategy. Mn 3 O 4 /SiO 2 /C exhibited an excellent IPM degradation efficiency, reaching 99.3 % within 30 min, compared with only 9.6 % IPM removal in the absence of catalyst ([cat] = 0.1 g L −1 , [IPM] 0 = 5 μM, [O 3 ] 0 = 3 mg L −1 , at pH 6.8 and 278 K). The Mn 3 O 4 , SiO 2 , and C in Mn 3 O 4 /SiO 2 /C were extensively integrated, and the proportion of Mn(II) in Mn 3 O 4 /SiO 2 /C was 39.9 %, as compared to 33.1 % in Mn 3 O 4 , which facilitated the generation of hydroxyl radicals. The siloxide and carbonaceous materials in Mn 3 O 4 /SiO 2 /C provided abundant sites for ozone adsorption and pollutant enrichment, promoting interfacial ozone contact with pollutants and subsequent catalytic reactions. The presence of structures such as Mn-O-Si and Mn-O-C in the material helps accelerate electron transfer, thus promoting electron capture and ozone decomposition. This strategy provides new insights for refractory pollutant elimination and serves as a guide for advancing green catalysis in water purification.
研究领域:
环境科学
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医学
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2025
·
IF 9
Rong Li,Yiziqi Lu,Meiqian Lu,Yue Liu,Guodong Zhang,Qiuling Ma,Jian Zhou,Tiecheng Wang
Iodinated X-ray contrast media, as a frequently used medical diagnosis in the imaging of internal organs, soft tissues, and blood vessels, are widely encountered in water environments because of their non-metabolic ability. Herein, a series of co-precipitates (DBC-FeO x ) of dissolved black carbon (DBC) and FeO x were successfully synthesized. The chelation of Fe species with COO – groups in DBC enhanced the excellent electron transfer capability and persulfate (PS) activation performance of the resulting DBC-FeO x , thus boosting iopamidol (IPM) degradation. The IPM removal rate constant in the DBC-FeO x /PS was 35 times and 4.6 times higher than those observed in the DBC/PS and FeO x /PS systems, respectively. There existed an appropriate C/Fe molar ratio in the DBC-FeO x co-precipitates for PS activation, and the IPM degradation was driven by both radical and non-radical pathways. Fe sites were the primary active sites in DBC-FeO x for PS activation, and C=O groups played an important role in accelerating the Fe(III)/Fe(II) cycle by promoting rapid electron transfer, thereby enhancing radical oxidation pathways. Concurrently, DBC-FeO x acted as an electron shuttle to promote the electron transfer from IPM to PS, creating non-radical pathways for IPM removal. IPM degradation processes involved amide hydrolysis oxidation, hydrogen extraction, and deiodination. The typical iodine species HOI was also converted to non-toxic IO 3 - after IPM decomposition, thus reducing potential risks.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
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