SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Menglan Gao,Zhibin Jiang,Xiaobin Liao,Xingji Bai,Huan Qi,Jing Zou,Wei Cao
Unsymmetrical dimethylhydrazine (UDMH) is found to generate substantial carcinogenic nitroso-dimethylamine (NDMA) during ozonation , moreover, its formation is promoted by ubiquitous bromide ions (Br − ) in water matrixes, but the mechanism is still unclear. In this study, effects of Br − on NDMA formation during ozonation of UDMH were studied, meanwhile, its promotion pathways were also determined. The results demonstrated that Br − promoted NDMA formation from UDMH during ozonation, the formation rate constant with Br − is over 7 times of that without Br − . NDMA amount raised from 142.5 to 327.5 μg/L when Br − dosages increased from 0 to 100 μM. No matter with or without Br − , the augment of O 3 dosages facilitated NDMA formation; the maximum value was achieved at pH 8. NDMA decreased dramatically from 173.8 to 123.5 μg/L with HCO 3 − raising from 0 to 160 μM, while increasing remarkably to 222.5 μg/L with SO 4 2− dosing. In addition, NOM inhibited NDMA formation from UDMH during ozonation. The mass spectrum of LC-MS/MS verified that the generation of Br-UDMH was main cause for promoting NDMA formation. Moreover, hypobromous acid (HBrO) was confirmed to be responsible for Br-UDMH formation. In addition, the position that oxidants and Br − attacked was demonstrated based on Gaussian calculation. The results of this study could provide theoretical basis for the application of ozonation in bromine-containing water matrixes.
研究领域:
环境科学
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毒理学
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化学工程
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DOI
高影响因子
Environmental Science-Water Research & Technology
·
2020
·Vol. 6
·期 10
·2766-2775
·
IF 3.449
Huan Qi,Qing Lin,Mengyi Chen,Xiaobin Liao,Jie Chen,Fei Li,Baoling Yuan
Daminozide (DMNZD) has been found to be an important ozone-reactive N-nitrosodimethylamine (NDMA) precursor; however, the influence of humic acid (HA) on NDMA formation from daminozide during ozonation is unclear. In this study, the impacts of HA on NDMA formation from daminozide at various oxidation conditions (ozone dosages, pH) and other water components (bicarbonate ion (HCO3−), sulfate ion (SO42−)) were investigated. In addition, its implications for water treatment plants are discussed. The results indicated that low levels of HA (≤0.6 mg L−1) facilitated NDMA formation and its molar yield was maximized at 0.1 mg L−1 HA (8.5%), while a high concentration of HA (>0.6 mg L−1) had an inhibition role. The NDMA amount increased with increasing pH and showed a peak at pH 8. With 0.1 mg L−1 HA, NDMA was raised from 3.0% to 23.1% with ozone increasing from 0.5 to 4 mg L−1; HCO3− competed with daminozide for ozone and cut down NDMA formation, whereby 160 μM HCO3− reduced NDMA conversion from 8.5% to 6.5%; however, with the increase in SO42− from 0 to 20 μM, NDMA conversion was augmented from 8.5% to 17.8%. Based on the results of LC/MS/MS and GC/MS analyses, NDMA transformation pathways with/without HA are proposed.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Rui Miao,Youya Zhou,Pei Wang,Wei Lu,Pu Li,Xiaoyan Li,Lei Wang
Pre-chlorination and pre-ozonation are the two most common pre-oxidation processes for fouling control of ultrafiltration membranes. However, few studies have explored and compared their effect mechanisms on membrane fouling behavior at the interfacial forces level. Accordingly, bull serum albumin (BSA) was used, and the changes in the interaction forces of BSA at the membrane surface after pre-chlorination and pre-ozonation were investigated. The results were combined with macro/micro analyses to unravel the effect mechanisms of chlorination and ozonation on membrane fouling behavior. Results demonstrated that the changes in the hydrophobic forces, hydrogen bonds and electrostatic repulsive forces between the membrane and BSA and between BSA molecules after pre-chlorination and pre-ozonation, were beneficial for membrane fouling control in theory, but not helpful. These changes in the non-covalent bonds appear to be completely masked by changes in disulfide bonds. The chlorination could break the disulfide bonds between BSA molecules, while ozonation could promote their formation. As a result, the deposition behavior of BSA onto the membrane surface and the structures of corresponding fouling layers after pre-chlorination were quite different from those after pre-ozonation. Finally, two different membrane fouling behaviors were observed that membrane fouling was definitively mitigated by pre-chlorination but enhanced by pre-ozonation.
研究领域:
环境科学
·
生物化学
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Yilin Dong,Jing Sun,Xiaoling Ma,Wenlong Wang,Zhanlong Song,Xiqiang Zhao,Yanpeng Mao,Wenxiang Li
MnO x has received widespread attention in low-temperature catalytic oxidation of VOCs, however, the synergy effect of MnO x and support on the VOCs catalytic ozonation were rarely studied. In this study, five different MnO x /X (X: MCM-41, 13X, ZSM-5, HY, USY) were synthesized and found their support greatly affect the catalytic oxidation activity. MnO x /MCM-41 presents the largest specific surface area, pore volume and unique surface morphology, and thereby provides more sites for MnO x loading and VOCs adsorption. Moreover, MnO x /MCM-41 presents a high proportion of Mn 3+ , which helps to enhance the ion exchange capability, and thus promotes the regeneration of oxygen vacancies. Furthermore, a part of Mn was proved to be introduced into the MCM-41 lattice, which can promote the electron transfer between the active components and the support, and thereby effectively improve the surface electronic properties of the catalyst. The toluene catalytic experiments showed that MnO x /MCM-41 exhibited the best catalytic activity , presenting complete degradation of O 3 and VOCs at room temperature. In addition, 5 wt%MnO x /MCM-41 exhibited better catalytic activity than other loading, and its higher surface oxygen species endowed it with strong water resistance and stability. In-situ DRIFTs indicated that toluene was initially oxidized into benzyl alcohol during the adsorption process, and then decomposed to intermediate products (benzaldehyde, phenolate, etc.) during the catalytic ozonation process, and finally oxidized to carbon dioxide. In conclusion, the supply of loading sites and the improvement of interfacial electron transfer are the manifestations of the synergy between the support and MnO x , leading to the promotion of the catalytic ozonation of VOCs.
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2018
·
IF 7.051
Da Wang,Haodan Xu,Jun Ma,Stefanos Giannakis,Xiaohui Lu,Huizhong Chi,Shuang Song,Jingyao Qi
A light-weight granular mixed-quartz sand (denoted as L-GQS) combined with stirring-assisted bubble column reactor was firstly applied in catalytic ozonation of atrazine. The L-GQS, with a density of 2.36 g cm −3 and average diameter of ca. of 4 mm, was readily churned up and uniformly distributed within the solution in the reactor. The introduction of L-GQS was found to exhibit enhanced catalytic ozonation of atrazine, with the increase in degradation rate and the dissolved organic carbon (DOC) removal being more than 2-fold for the catalytic process (L-GQS dosage = 5 g L −1 , [atrazine] 0 = 50 μM, [O 3 ] = 25 mg L −1 , gas flow = 0.2 L min −1 , at pH 7.0 and 293 K). The L-GQS settled at the bottom of the reactor after experimentation, allowing its easy separation from the solution. A complete characterization of the material (XRD, XPS, FTIR , FE-SEM/EDS, BET and pH pzc ) revealed that L-GQS consisted of α-quartz, β-cristobalite, anorthoclase and small amount of iron oxy-hydroxides. Hydroxyl groups, Bronsted acid sites and Lewis acid sites on the surface of L-GQS all contributed to the atrazine adsorption, ozone decomposition and ·OH generation. The L-GQS catalyzed ozonation exhibited superior atrazine degradation and mineralization rates in a wide range of pH (3.0–9.0) and reaction temperatures (278 K–293 K). Also, an enhancement of DOC abatement was observed both in presence of natural organic matter isolates and natural water matrices (river water) when L-GQS was used. Finally, the degradation mechanism was proposed, based on the intermediates and by-products formation analyzed by LC-QTOF-MS/MS and ionic chromatography. Our results indicate that the L-GQS combined with stirring-assisted bubble column reactor could be utilized as an enhancement of ozone-based advanced oxidation processes .
研究领域:
环境科学
·
化学工程
·
水处理
·
催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Menglan Gao,Xiaobin Liao,Shuting Chen,Xiaoying Li,Yirou Zhang,Chao Chen,Huan Qi
Bromide ion (Br - ) in water sources has been found to affect the formation of carcinogenic non-brominated N-nitrosodimethylamine (NDMA) during ozonation of typical amines. The increasing bromide levels bring more concern due to climate change and industrial discharge, but its effects on actual water matrixes were still unclear. In this study, NDMA formation from three actual water matrixes during ozonation as the Br - concentration increased from 0 to 100 µM were investigated (promotion (100.4 ∼ 231.6 ng/L), promotion then inhibition (399.5 ∼ 461.2 ∼ 428.2 ng/L), and subtle influence (51.9 ± 6.9 ng/L)); from which the NDMA precursors were screened and 8 precursors were selected for exploring the influencing mechanisms. The results indicated that the roles of Br - on NDMA formation significantly depended on the water characteristics of actual matrixes. A total of 16 typical NDMA precursors, which were mainly derived from industrial, agricultural and pharmaceutical sources, were identified. Moreover, 6 brominated substance (Br-DMA, Br-UDMH, Br-DMSC, Br-DMS, Br-TMDS, Br 2 -TMDS), which were thought to play a crucial role in promoting NDMA formation, were also identified in actual water by precursor ion scan (PIS) method. Hypobromous acid (HOBr), which has been proved to be the culprit to the generation of brominated substances, tend to attack the electron-donating groups of amines, such as acylamino (–NHCO-R) or amidogen (–NH 2 ) groups. However, the reactive bromine species (∙Br and ∙Br 2 - ) was inclined to attack the aromatic and anti-oxidant moieties then result in Br - release, as no bromine substitution but free radical transfer reaction occurs. Therefore, decreasing HOBr formation is the crucial step to reduce NDMA generation. This work would provide technical guide for NDMA risks control during ozonation of Br - -amines co-containing water matrixes.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Fan Bu,Baoyu Gao,Xue Shen,Wenyu Wang,Qinyan Yue
Ultrafiltration (UF) technology is considered an efficient water treatment method. In recent years, researchers have been committed to enhancing the treatment efficiency of UF and alleviating membrane fouling. An effective method is to achieve this is through the use of coagulation as a pre-treatment to UF; however, during a long term operation, membrane fouling can occur due to the residual organic matters and the generation of microorganisms . In this study, we combine coagulation and ozonation as a pre-treatment of UF and compare four types of pre-treatment: coagulation, ozonation, coagulation followed by ozonation (C–O) and ozonation followed by coagulation (O–C). Results showed that ozonation alone did not perform well. Both combinations of coagulation and ozonation enhanced the organic matter removal efficiency, although membrane fouling was lowest following the C–O pre-treatment as the microbial load was reduced. While a slight increase in the yield of disinfection by-products was observed with the addition of ozonation, the concentration remained below the Chinese standard for tap water quality (100 μg/L).
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Menglan Gao,Zhibin Jiang,Xiaobin Liao,Huan Qi,Lei Zhao,Chao Chen,Danielle Westerman
Aliphatic amines, common constituents that contribute to dissolved organic nitrogen (DON), can quickly react with ozone due to the lone electron pair on the nitrogen atom and this may produce carcinogen N -Nitrosodimethylamine (NDMA). 3-(Dimethylamino)-1-propylamine (DMAPA) was chosen as a representative to elucidate the NDMA formation characteristics, kinetic rates, reaction pathways, and influencing factors during ozonation in this study. The results demonstrated that NDMA generated directly from DMAPA during ozonation. Moreover, the NDMA yields increased with ozone dosages. The NDMA molar yield increased and then decreased when the pH raised from 5 to 9, achieving the maximum value at pH 8. Hydroxyl radical (∙OH) played a promotional role in NDMA formation, and its scavenger dramatically cut down its yields. Low levels of Br − facilitated NDMA formation, while the value significantly reduced when Br − was up to 1 mM. The NDMA amount was slightly raised by NO 2 − , but it was inhibited by NH 4 + and NO 3 − . Moreover, it was also depressed by co-existing components in actual lake water. Based on the result of the Gaussian calculation, the LC-MS/MS and GC–MS analysis, four possible transformation pathways were proposed. The radical recombination was verified to be the primary pathway for ozone promoting NDMA formation from DMAPA.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL ENGINEERING
·
2025
·Vol. 151
·期 8
·04025043
·
IF 1.6
Jie Zhang,Mengchen Zong,Ben Dong,Sijie Ge,Shilong He
Quinoline, as one of the typical toxic and refractory organic pollutants in coal chemical industry wastewater, poses a significant threat to human health and environmental quality. In this study, MnCexOy and MnFexOy catalysts were successfully synthesized by doping Ce3+ and Fe2+ into α-MnO2 at a molar ratio of 1∶10 and were applied to the process of catalytic ozonation for the degradation of quinoline. Additionally, a variety of characterization techniques were employed to elucidate the characteristics of the catalysts, including scanning electron microscopy, X-ray diffraction, Brunauer–Emmett–Teller (BET) analysis, X-ray photoelectron spectroscopy, H2-TPR, NH3-TPD. The results show that, in the catalytic ozonation system for quinoline removal, MnCexOy demonstrates excellent quinoline removal efficiency of 87.45%, which is higher than that of MnFexOy (78.83%) and unmodified α-MnO2 (62.67%). By introducing the surface hydroxyl masking agent HPO42−, the significant role of surface hydroxyl groups and oxygen vacancies in the catalytic degradation of quinoline by MnCexOy was further demonstrated. Exploring the surface characteristics of catalysts is beneficial for continued understanding of the active centers of catalysts. Research results will be helpful to the deep treatment and reuse of tailing water of coking wastewater.
研究领域:
环境科学
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Environmental Research and Public Health
·
2019
·Vol. 16
·期 8
·1439
·
IF 2.468
Yue Teng,Ke Yao,Wenbin Song,Yongjun Sun,Haoliang Liu,Zhiying Liu,Yanhua Xu
Cu-Mn-Ce@γ-Al2O3was prepared by incipient wetness impregnation and used to catalyze ozonation in a coal chemical wastewater-biotreated effluent. The preparation factors that considerably affected the catalytic performance of Cu-Mn-Ce@γ-Al2O3, specifically metal oxide loading percentage, calcination temperature, and calcination time, were examined. The catalyst was characterized by scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, and Brunauer-Emmett-Teller analysis. The optimal catalytic ozonation operating parameters, such as ozone dosage, catalyst dosage, pH, and reaction time, were also investigated. Results showed that an optimized catalyst consisted of 17.0% CuO, 3.0% MnO2, and 2.0% CeO2(wt.%). The optimal calcination temperature and calcination time were 600 °C and 5 h. The optimal catalytic ozonation operating parameters, including ozone dosage, catalyst dosage, pH, and reaction time, were 7, 80.0 mg/L, 20.0 mg/L, 7 and 50 min, respectively. The COD removal of biotreated effluent increased to 61% under these optimal operating conditions. Meanwhile, ozonation alone resulted in only 20% removal. This work proposes the use of easily available Cu-Mn-Ce@γ-Al2O3catalyst and might drive the advancement of catalytic ozonation for chemical wastewater purification.Keywords:catalyst;catalytic ozonation;coal chemical wastewater;advanced treatment
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Da Wang,Haodan Xu,Jun Ma,Xiaohui Lu,Jingyao Qi,Shuang Song
Tourmaline, an economical and eco-friendly natural mineral, has been widely used during the water treatment processes. In this investigation, the raw tourmaline has been found to be effective as a catalyst for ozonation in the degradation of atrazine (ATZ) under low temperature (278 K). Within typical experimental conditions (tourmaline dosage = 1 g L −1 , [ATZ] 0 = 5 μM, [O 3 ] 0 = 3 mg L −1 , at pH 7.0 and 278 K), the removal efficiency of ATZ in catalytic ozonation was 98% after 10 min, compared with only 27% ATZ removal in the absence of catalyst. Surface properties and components of tourmaline were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectra (FTIR), pyridine-FTIR and energy dispersive X-ray (EDX). The characterization studies showed that metal attached hydroxyl groups (M OH, M = Fe, Al and Si) were the main active sites for ozone adsorption and decomposition. The formation of hydroxyl radicals ( OH) as well as hydrogen peroxide (H 2 O 2 ) led to fast ATZ degradation and 31 kinds of intermediates; meanwhile, possible degradation pathways of ATZ were detected and proposed. The mechanisms of reaction were proposed for tourmaline-catalyzed ozonation based on all the experimental results and material characterizations.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 53
·80399-80410
·
IF 5.19
Shu Xinpeng,Bi Huaqi,Wang Jun,Yang Jiaxin,Wang Jue,Liu Guangqing,Su Bensheng
Catalytic ozonation with supported metal oxides is a promising strategy for addressing refractory pollutants in wastewater. In this study, γ-Al 2 O 3 supported MnO x -CeO x catalysts (MC 1 , MC 2 , and MC 3 ) obtained at different calcination temperatures (400 °C, 550 °C, and 700 °C) were applied as effective catalysts for ozonation and explored the feasibility of the treatment of oxytetracycline (OTC) wastewater. Comparatively, the MC 2 possessed the highest molar ratios of Mn 3+ /Mn 4+ (1.60) and Ce 3+ /Ce 4+ (0.96), the largest surface area (273.8 m 2 g −1 ) with a petal-shaped structure, and most abundant surface hydroxyls (3.78 mmol g −1 ). These physicochemical characteristics benefited the surface reaction and resulted in the acceleration of ozone decomposition, electron transfer, and •OH generation, thereby improving the catalyst’s adsorption ability and catalytic activity. The combination with MC 2 increased the OTC and COD removal of the ozonation process from 59.1% and 29.0% to 94.7% and 83.3% in 25 min, respectively. By employing electron paramagnetic resonance (EPR) and radical quenching experiments, it was verified that •OH species generation promoted the mineralization of OTC. The possible degradation pathways of OTC were investigated through mass spectrometry, and the route consisted of dehydration, deamination, and demethylation. Moreover, during a 12-day continuous experiment, MC 2 catalyst exhibited excellent reusability and catalytic stability, with COD removal efficiencies above 80%.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）