WATER AIR AND SOIL POLLUTION
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2022
·Vol. 233
·期 6
·1-10
·
IF 2.984
Xu Ying,Zhou Zhengwei,Xue Yingang,Wu Jun
Synthetic musks (SMs), as a group of pharmaceutical and personal care products (PPCPs), have been widely detected in the environment at ng L −1 ~ μg L −1 levels and require our serious attention regarding their presence, toxicity and treatment technologies. In this study, ferrate (Fe 2 O 4 2− , Fe(VI)) was employed to treat two typical SMs, galaxolide (HHCB) and tonalide (AHTN), in water solutions. The treatment efficiencies of trace level HHCB and AHTN compounds (16 μg L −1 each) in individual and mixed solutions by Fe(VI) (0–45 mg L −1 as Fe) at pH 5.5–8.5 were assessed, and oxidation products of both compounds were also investigated by means of solid phase extraction coupled with gas chromatography-mass spectrometry (SPE-GC–MS). Results demonstrated that Fe(VI) was more suitable to remove HHCB than AHTN from test solutions. Specifically, when solution pH was 6.5 and Fe(VI) dose was 15–18 mg L −1 as Fe, the removal efficiencies of HHCB and AHTN in individual test solutions were up to 60% and 40%, respectively. Comparatively, much higher Fe(VI) doses were required (up to 38 mg L −1 as Fe) in order to achieve considerable removal efficiencies of both compounds in mixed test solutions. Solution pH played an important role and neutral conditions would benefit the removal of both compounds. In addition, several oxidation products (OPs) of both HHCB and AHTN were identified, and degradation pathways were then tentatively proposed. Finally, engineering aspects of Fe(VI) technology in full-scale water treatment applications were also discussed.
研究领域:
环境科学
·
水处理技术
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2017
·
IF 3.359
Chaoyi Wang,Chongwei Li,Haipu Li,Hsiaowan Lee,Zhaoguang Yang
2-isopropyl-3-methoxypyrazine (IPMP) and 2-isobutyl-3-methoxypyrazine (IBMP) are two of main taste and odor compounds in drinking water. The removal efficiency and possible degradation pathway of IPMP and IBMP by ozonization were studied by evaluating experimental parameters including ozonization time, initial concentration of IPMP and IBMP, and solution pH. At pH 6.8 the removal efficiency of IPMP and IBMP (100 ng L −1 ) were both found over 90% within 15 min ozonization, and a higher pH value (8.6) helped to accelerate the degradation in some degree. In both neutral and acidic media, the degradation followed the pseudo first order kinetics. In contrast, at lower pH range, e.g. pH 5.0, more than 10% of the title compounds were still existing even after 30 min ozonization. With increasing the initial concentration from 100 to 200 and to 400 ng L −1 , the removal efficiency of the title compounds was decreased successively. The intermediate by-products of IPMP and IBMP by ozonization were mainly acid esters and carboxylic acids as identified by GC–MS, and accordingly the possible degradation pathway was proposed.
研究领域:
环境科学
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水处理工程
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DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Liying Jiang,Zhiwei Yao,Pengju Wang,Jianmeng Chen,Yufen Zhang,Wu Huang,Xiang Cao,Yufeng Xu
Plasma-catalytic removal of chlorobenzene (CB) was conducted in a dielectric barrier discharge (DBD) reactor over two manganese-based catalysts, LaMnO 3 and cryptomelane-type octahedral molecular sieve (OMS-2). The physicochemical properties of two catalysts were characterized by XRD , SEM, TEM , BET, XPS and H 2 -TPR. It was shown that OMS-2 catalyst had larger surface area, smaller particle size, better redox properties, higher ratio of Mn 4+ /Mn 3+ and higher content of surface-adsorbed oxygen (O ads ). The introduction of manganese-based catalysts enhanced CB removal, increased the CO 2 selectivity , and inhibited ozone (O 3 ) and NO x formation. OMS-2 exhibited a better degradation, mineralization and energy yield, with 89.5% of CB degradation, 57.6% of CO 2 selectivity and 0.54 g kWh −1 at discharge voltage of 6 kV, than LaMnO 3 in the NTP-catalytic reactor and this was ascribed to more active sites, more O ads , higher redox property and better O 3 decomposition ability on OMS catalyst surface. The two manganese-based catalysts were stable in the NTP-catalysis system although some intermediate byproducts were deposited on the catalyst surface during the 24-h activity cycling tests. Moreover, the intermediate byproducts were analyzed by GC/MS, and then the possible degradation pathways of CB decomposition in the plasma-catalysis system were suggested.
研究领域:
环境科学
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催化化学
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Mengfan Luo,Heng Zhang,Peng Zhou,Jiali Peng,Ye Du,Zhaokun Xiong,Bo Lai
The sluggish oxidation kinetics of ferrate (Fe(VI)) at neutral and slightly alkaline pH impedes its rapid abatement of micropollutants in practical application. This work discovers that graphite (GP), a metal-free carbonaceous material , can be a promising material to improve the reactivity of Fe(VI) in the pH range of 7.0 − 9.0. The performance of the GP/Fe(VI) process for sulfamethoxazole (SMX) removal was further evaluated via altering the dosages of Fe(VI), GP, and SMX. Probe analysis and quenching experiments identified Fe(IV) and Fe(V) as the primary active species responsible for the removal of organic compounds in the GP/Fe(VI) system. The detailed activation mechanism of GP is discussed via analyzing the surface chemical changes of GP exposed to Fe(VI). It is found that the carbonyl groups on GP surface execute a critical role in Fe(VI) activation. The GP/Fe(VI) system shows powerful anti-interference ability to environmental background substances. Therefore, the new oxidation process proposed in this work holds a great application prospect for contamination remediation. Finally, we discuss the underlying degradation pathways of SMX by the GP/Fe(VI) system. This study not only develops a promising system for the removal of micropollutants but also provides an in-depth insight into the activation mechanism of metal-free carbonaceous material in Fe(VI) oxidation process.
研究领域:
环境科学
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化学
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Hui Cao,Yinhao Dai,Leliang Wu,Chengdu Qi,Linlin Hou,Dequan Zhang,Yao Li,Chenmin Xu,Huan He,Shaogui Yang
Advanced oxidation processes based on peracetic acid (PAA) activation have received more attention in water treatment recently. In this study, the degradation of iohexol (IOH, a classical iodinated X-ray contrast media) in the Co(II)/PAA system under neutral conditions, which mainly produced carbon-centric radicals, was investigated. Results showed that IOH decomposition follows the pseudo-first-order kinetic with a rate constant of 0.283 min −1 . Appropriately increasing concentrations of PAA or Co(II) could promote the removal of IOH, while elevating the dosage of H 2 O 2 inhibits the elimination of IOH in the Co(II)/PAA system. The IOH elimination was affected by pH, with the best response in pH between 5 and 7 in the Co(II)/PAA system. Additionally, low Cl − doses have negligible effects whereas high Cl − impeded the breakdown of IOH. Br − , I − , HCO 3 − , H 2 PO 4 − and humic acid suppressed the degradation of IOH. Removal of IOH was significantly inhibited in three selected real water samples. Furthermore, six IOH degradation pathways, including H-abstraction, amide hydrolysis, amino oxidation, deiodination reaction, hydroxylate and elimination reaction, were proposed on the basis of the liquid chromatography-tandem mass spectrometry , ion chromatography and DFT theoretical calculations (Frontier electron densities and fukui functions) results. Finally, the ECOSAR assessment showed that some degradation byproducts were much more toxic than IOH parent, but were much more biodegradable. Overall, this study indicates a potential risk when applying the carbon-centric radicals involved in PAA-based AOPs to remediate halogenated organic pollutants in water.
研究领域:
环境科学
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化学
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DOI
高影响因子
Agronomy-Basel
·
2024
·Vol. 14
·期 12
·2959
·
IF 3.3
Zhijia Cheng,Zhongbin Lu,Zhiwei Shao,Bowen Huang,Yang Xiong,Hongqiang Fei,Xian Wu,Yanwei Liu,Mei Li,Zhiguang Hou,Zongzhi Lu
The photolysis kinetics of propaquizafop in water under ultraviolet light was investigated in this study, and the effects of different influencing factors (pH,NO3−, metal ions) on the photolysis of propaquizafop were clarified. Propaquizafop residues in water were determined by a HPLC-UV detector. The results showed that the pH of the aqueous solution had no significant effect on the photolysis of propaquizafop (p< 0.05). The lowNO3−, concentration (0.5~2 mmol/L) had a weak inhibitory effect on the photolysis of the propaquizafop; when the concentration ofNO3−was 4 mmol/L, the degradation half-life of the propaquizafop was significantly higher than with other treatments (p< 0.05); Different concentrations of Fe3+had varying degrees of inhibitory effects on the photolysis of propaquizafop. The inhibitory effect was stronger at low concentrations (0.5 mmol/L and 1 mmol/L) and weaker at high concentrations (2 mmol/L and 4 mmol/L). As the concentrations of Cu2+, Cd2+, Mn2+, Zn2+, and Ni2+increased, their inhibitory effect on the photolysis of propaquizafop in an aqueous solution became stronger. In addition, LC–QTOF-MS was used to identify the photoproducts of propaquizafop in aqueous solution in this study. Five types of photoproducts were identified, and several propaquizafop degradation pathways and mechanisms were proposed, mainly including rearrangement, cracking reactions, dechlorination reactions, and light-induced redox reactions. The results of this study will help us to better understand the photodegradation law of propaquizafop in aqueous solution and provide data support for its safety evaluation in water.
研究领域:
环境科学
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分析化学
·
农药学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Zhuyu Sun,Dan Geng,Chaojie Zhang,Jiabin Chen,Xuefei Zhou,Yalei Zhang,Qi Zhou,Michael R. Hoffmann
Due to the extremely high stability of perfluorooctane sulfonate (PFOS), effective defluorination is difficult. Previous studies indicated that PFOS can be decomposed under the catalysis of vitamin B12 (VB12) with strong artificial reductants such as Ti(III)-citrate and nZn 0 . In this study, we explored if naturally occurring reductant like sulfide (S 2− ) could initiate the reaction. In S 2− /VB12 system, branched PFOS (br-PFOS) can undergo effective decomposition and defluorination at the temperature of 70 °C and pH greater than 12. The degradation of br-PFOS fits pseudo-first-order kinetic with a rate constant of 0.0984 ± 0.0034 d -1 in the presence of 30 mM Na 2 S and 300 μM VB12, while linear PFOS (L-PFOS) remained stable during 30 d reaction process. UV–Vis spectral characterization indicates that S 2− reduces VB12(Co III ) to Co II , which is able to initiate the reductive defluorination. Based on the product analysis, HF/2F elimination followed by C–C scission is the dominant degradation pathway of br-PFOS instead of stepwise H/F exchange. The primary products include F − and polyfluorinated sulfonates and carboxylates. The degradation of br-PFOS is strongly dependent on temperature due to a relatively high apparent activation energy of 62.86 kJ/mol. Strong alkaline condition can greatly enhance the decomposition efficiency since S 2− is the primary reactive form. This study provides new insights into the VB12-catalyzed defluorination of PFOS and a feasible approach for future natural or engineered remediations of br-PFOS.
研究领域:
环境科学
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化学
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DOI
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Ruihan Xiong,Zhuojun Lu,Qian Tang,Xueling Huang,Huazhen Ruan,Wei Jiang,Yiqun Chen,Zizheng Liu,Jianxiong Kang,Dongqi Liu
This study reports on the propranolol (PRO) degradation performance and product toxicity of an ultraviolet light-emitting diode (UV-LED)/chlorine process. The effects of experimental parameters including solution pH, chlorine dosage, and water matrix constituents on PRO removal were evaluated. Up to 94.5% of PRO could be eliminated within 15 min at a PRO-to-chlorine molar ratio of 1:4. The overall removal efficiency of PRO was non-pH dependent in the range of 5–9, while the initial rate was accelerated under alkaline conditions. The presence of Cl − /HCO 3 − had little influence on the PRO degradation, whereas either humic acid or NO 3 − had an obvious inhibitory effect. Radical scavenger experiments showed that both HO and Cl primarily contributed to the PRO degradation, and electron paramagnetic resonance data demonstrated the generation of 1 O 2 . The transformation of PRO during this process led to five detected products, which exhibited a higher acute toxicity than the parent compound according to the bright luminescent bacillus T3 method. It is worth mentioning that under the same ultraviolet illumination intensity, the degradation of PRO under UV-LED/chlorine gave a better performance than UV 254 /chlorine, but the EEO of the former is obviously higher than the latter. So further research is required on improving the electric current to photon conversion efficiency for UV-LED. Additionally, the UV-LED/chlorine system was effective in the degradation of other drugs including sulfamethoxazole, oxytetracycline hydrochloride, and gatifloxacin, suggesting the possible application of the UV-LED/chlorine process for the removal of pharmaceuticals during wastewater treatment .
研究领域:
环境科学
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毒理学
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水处理工程
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yusi Tian,Minghua Zhou,Yuwei Pan,Xuedong Du,Qi Wang
Molybdenum sulfide (MoS 2 ) was for the first time used as a co-catalyst to enhance the performance of Fe 0 based heterogeneous electro-Fenton (Fe 0 -EF) process for the degradation of sulfamethazine (SMT), which was belonging to the sulfonamide family and extensively used as growth promoters and antibacterial drugs. Compared with Fe 0 -EF process, MoS 2 /Fe 0 -EF process could enhance the rate constant of SMT degradation 2 times under the optimal conditions of current 50 mA, MoS 2 dosage 0.02 g L -1 , Fe 0 dosage 0.224 g L -1 , and initial pH 4, in which SMT could be completely degraded within 10 min while 42% TOC could be achieved after 60 min reaction. The role of MoS 2 as co-catalyst in MoS 2 /Fe 0 -EF process and Fe 2+ /Fe 3+ cycle was supported by iron elemental analysis, transmission election microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) characterizations. Owing to the characteristics of co-catalysis, MoS 2 could greatly facilitate the Fe 3+ /Fe 2+ recycle reaction by the exposed Mo 4+ active sites, which significantly promoted the decomposition of H 2 O 2 that generated in Fe 0 -EF system and improved the generation of hydroxyl radical. Besides, a possible degradation pathway of SMT was proposed and the stability of MoS 2 /Fe 0 -EF process for SMT removal and TOC mineralization was certified base on five consecutive runs. The real wastewater test and energy consumption and economic analysis confirmed its advantage and cost-effectiveness for application. In all, this study provides a new perspective for improving heterogeneous Fe 0 -EF process with MoS 2 for highly efficient and rapid degradation of antibiotics.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2021
·
IF 4.291
Jian-Bo Chen,Taishan Yan,Chaofeng Wang,Ruixia Gao,Silong Xu,Guijuan Fan,Xueyan Zhao,Yu Liu
The dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50), as an outstanding representative of nitrogen-rich energetic salts, has recently attracted increasing interest due to its excellent performances. However, it is unclear about the photostability and degradation pathways of TKX-50 in aqueous solution. In this paper, the photostability and the degradation process of TKX-50 in aqueous solution have been comprehensively studied for the first time. TKX-50 can keep stable toward visible light. However, it presented a rapid degradation with rate constant of 0.0054 s −1 under 254-nm light irradiation. TKX-50 also demonstrated much faster photodegradation than traditional nitro explosives. Further, degradation products of TKX-50 were analyzed by high-resolution mass spectrum with theoretical calculations. The photodegradation pathways are proposed that 5,5′-bistetrazole-1,1′-diolate (BTO) anion of TKX-50 can been fragmented into the nitrile by losing N 2 and HNO, and then hydroxylammonium (NH 3 OH + ) from TKX-50 reacts with the nitrile through the nucleophilic addition. Besides as a solvent, water also may accelerate the photodegradation of TKX-50 probably by hydrolyzing the intermediary nitrile products. In a word, this study provides comprehensive understanding about the photostability of TKX-50 in aqueous solution, and it is helpful to study the photochemistry of other energetic ionic salts based on BTO.
研究领域:
化学
·
材料科学
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DOI
高影响因子
AMB Express
·
2019
·Vol. 9
·期 1
·1-9
·
IF 2.226
Zhao Shuxue,Hu Chunhui,Guo Lizhong,Li Kuiran,Yu Hao
A 3-hydroxypyridine degrading bacterium, designated strain DW-1, was isolated from petroleum contaminated soil in Liao River China. 16S rRNA-based phylogenetic analysis indicates that strain DW-1 belongs to genus Agrobacterium. The optimal cultivation temperature and pH for strain DW-1 with 3-hydroxypyridine were 30 °C and 8.0, respectively. Under optimal conditions, strain DW-1 could completely degrade up to 1500 mg/L of 3-hydroxypyridine in 66 h. The 3-hydroxypyridine degradation pathway of strain DW-1 was suggested by HPLC and LC–MS analysis. The first reaction of 3-hydroxypyridine degradation in strain DW-1 was α-hydroxylation so that the major metabolite 2,5-dihydroxypyridine was produced, and then 2,5-dihydroxypyridine was transformed by a Fe2+-dependent dioxygenase to form N-formylmaleamic acid. N-Formylmaleamic acid will be transformed to maleic acid and fumaric acid through maleamic acid. This is the first report of the 3-hydroxypyridine degradation pathway and the utilization of 3-hydroxypyridine by a Agrobacterium sp. It may be potentially used for the bioremediation of environments polluted with 3-hydroxypyridine.
研究领域:
微生物学
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环境科学
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2021
·
IF 10.588
Ying Cai,Shihao Shen,Jinhong Fan
This study applied a mineral material of FeS to activate sulfite for efficient degradation of TTC in the presence of Cu(II) based on the identified complexation mechanism through UV–Vis spectra, FTIR spectroscopy and DFT calculation . pH plays an important role in TTC degradation and the initial pH of 6 and 7 were the divide in the contributions of FeS/sulfite oxidation and complex-precipitation. TTC-Cu(II) exhibits a superior promoting effect on the TTC degradation in FeS/sulfite system due to the improvement of TTC electron transfer reactivity and Fe(II) dissolution from FeS. Moreover, the formation of Cu(I) improved the recycling of Fe(II) from Fe(III). Dissolved oxygen-dependent free radicals’ generation was confirmed, and TTC degradation was mainly attributed to SO 4 ·− and ·OH. The characterization of FeS surface through XPS, XRD , SEM-EDS, Fe(II) deactivation tests, together with the comparison of pseudo-first-order rate constants for TTC degradation by FeS and ferrous ion supported the important role of surface and dissolved Fe(II) in sulfite activation . Furthermore, reasonable degradation pathways of TTC have been proposed according to the detected products by LC-MS. This work highlights the important role of pH, DO and Cu(II) complexation in sulfite activation and TTC degradation, furnishing theoretical support for further relevant studies.
研究领域:
环境科学
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化学
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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）