CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Yuefei Ji,Changxun Dong,Deyang Kong,Junhe Lu,Quansuo Zhou
Contamination of herbicides such as atrazine (ATZ) poses a significant threat to human health and aquatic ecosystem. In this study, we demonstrated that heat-activated persulfate could effectively degrade ATZ in water. Complete disappearance of 50 μM ATZ could be obtained after 2 h reaction in the presence of 1 mM persulfate under 60 °C. Increasing the initial persulfate concentration or temperature significantly enhanced the degradation efficiency. Natural organic matter (NOM) decreased the degradation rate, but complete removal of ATZ could still be obtained. The presence of chloride (Cl − ) and bicarbonate (HCO 3 − ) had little effects on ATZ degradation at lower concentration (e.g., 5 mM). However, inhibitory effects were observed when concentrations of Cl − and HCO 3 − increased (e.g., 100 mM). Radical scavenging test revealed that sulfate radical (SO 4 − ) was the predominant radical species at acidic to neutral pH, while hydroxyl radical (HO ) was predominant at basic pH. Eight intermediates and products were identified by applying solid phase extraction and liquid chromatography–tandem mass spectrometry (SPE-LC–MS/MS) techniques. Transformation pathways including dealkylation, alkyl chain oxidation, and dechlorination–hydroxylation were proposed, and the underlying mechanisms for each pathway were systematically analyzed.
研究领域:
环境科学
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水污染治理
✓ 已验证
DOI
高影响因子
Catalysts
·
2019
·Vol. 9
·期 11
·906
·
IF 3.444
Jieyang Yang,Zequan Zeng,Zhanggen Huang,Yan Cui
In this work, the activation effect of vacuum thermal treatment on MIL-101(Fe) (MIL: Materials of Institute Lavoisier) was investigated for the first time. It demonstrated that vacuum thermal activation could accelerate the activation of persulfate (PS) by MIL-101(Fe), and the enhancement of the catalytic capacity of MIL-101(Fe) was mainly attributed to the change in the FeII/FeIII mixed-valence center. The results of the SEM and XRD showed that vacuum thermal activation had a negligible effect on the crystal structure and particle morphology of MIL-101(Fe). Meanwhile, the higher temperature of vacuum thermal activation caused a higher relative content ratio of FeII/FeIII. A widely used azo dye, X-3B, was chosen as the probe molecule to investigate the catalytic performance of all samples. The results showed that the activated samples could remove X-3B more effectively, and the sample activated at 150 °C without regeneration could effectively activate PS to remove X-3B for at least 5 runs and approximately 900 min. This work highlights the often-overlooked activation effect of vacuum thermal treatment and provides a simple way to improve the catalytic capacity and reusability of MIL-101(Fe) which is beneficial for the application of MIL-101(Fe)/PS systems in azo dye wastewater treatment.Keywords:vacuum thermal activation;MIL-101(Fe);persulfate;azo dye
研究领域:
环境科学
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催化
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Sustainable Metallurgy
·
2025
·
IF 3.2
Shao Shuang,Ma Baozhong,Wang Chengyan,Chen Yongqiang
Extracting Al from coal gangue has the double benefits of realizing the high-value application of coal gangue and mitigating the scarcity of bauxite resource. The key Al-containing minerals in coal gangue include kaolinite and boehmite, and thermal activation is pivotal for stimulating their reactivity. In this study, kaolinite and boehmite were subjected to thermal activation and acid leaching to explore the intrinsic link between their thermal evolution and leaching activity. Results showed that the phase evolution of kaolinite followed a multi-step sequential process in the order of kaolinite → metakaolinite → γ -Al 2 O 3 → mullite, and Al V in metakaolinite was highly active. For boehmite, it underwent the transformation of boehmite → γ -Al 2 O 3 → δ -Al 2 O 3 → θ -Al 2 O 3 and α -Al 2 O 3 successively. Their reactivity in descending order was γ -Al 2 O 3 > δ -Al 2 O 3 > boehmite > α -Al 2 O 3 . Furthermore, a comparative study of leaching temperature demonstrated that elevated temperature favorably strengthened the thermodynamic driving force and greatly promoted the Al extraction. This study is of some theoretical significance for guiding the thermal activation and acid leaching of coal gangue. Graphical
研究领域:
矿物加工
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材料科学
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冶金学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Guanhong Liu,Chao Li,Brittney Ashley Stewart,Lin Liu,Meng Zhang,Mingyang Yang,Kuangfei Lin
The chemical degradation performance of perfluorooctanoic acid (PFOA), one of the environmentally persistent contaminants, by fresh activated carbon (FAC) and nitrogen-doped activated carbon (NAC) which were used as heterogeneous catalysts in the presence of thermal activating peroxymonosulfate (PMS) were investigated and compared. In this study, the physicochemical properties of FAC and NAC are characterized by scanning electron microscope, Raman spectra, Fourier transform infrared spectra, X-ray photoelectron spectroscopy, and Brunauer Emmett Teller. Furthermore, the dosing amount of catalyst, the concentration of oxidant and the effect of catalytic oxidation are investigated. During the catalytic oxidation process, the concentrations of PFOA and its degradation products are determined by high-performance liquid chromatography combined with tandem mass spectrometry (HPLC-MS/MS). The mineralization efficiency of PFOA employing FAC and NAC coupled with thermal activation of PMS are evaluated via a combination approach of total organic carbon (TOC) and ion chromatography (IC). The results indicate that PFOA can be readily degraded at 60 °C with an optimum concentration of PMS and an appropriate dosage of FAC/NAC. During the degradation process FAC and NAC exhibit superior adsorption and catalytic performance as more acidic oxygen functional groups are obtained from surface modification, which can facilitate the decomposition of PMS and the mineralization of PFOA. Electron paramagnetic resonance detection confirms that both OH and SO 4 − exist during oxidation. Based on the identified products, a reaction pathway including adsorption, hydroxylation, and catalytic oxidation is proposed. The methods could not only be applied in a wide pH range to effectively remove PFOA, FAC/PMS and NAC/PMS could also be reused, which provide a feasible and cost-effective method for the degradation of PFOA in situ actual ground water remediation.
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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Shuyin Zhang,Jing Zou,Lingxuan Chen,Chunhua Shen,Jian Lu,Jianlin Zhang,Hangyu Cui,Geng Huang,Jun Ma
Although thermal-activated peroxymonosulfate (PMS) system possesses good performance on the removal of organic pollutants, thermal/PMS system exhibited poor capacity to remove ammonia nitrogen (NH 4 + -N). This study demonstrated the huge enhancement on the removal of NH 4 + -N by thermal/PMS system with the commonly coexistent bromide ion (Br - ). The elimination of NH 4 + -N by thermal/PMS/Br - system fitted the pseudo -zero-order kinetics model well, while the corresponding k obs in the presence of 200 μM Br - was 5.76 times greater than that by thermal/PMS system. Bromine (HBrO) was confirmed as the dominant oxidant responsible for removing NH 4 + -N and TN, while the radicals of HO ⋅ , SO 4 ⋅- and Br ⋅ were also generated but made minor contribution to removing NH 4 + -N. HBrO was mostly produced by PMS reacting directly with Br - , while these radicals were produced from the cleavage of the O-O bond in PMS and the reaction between PMS and HBrO under high temperature. Thermal/PMS/Br - system exhibited superior performance on TN removal (up to 90 %) than that by thermal/PMS system (less than 5 %) and Cl - -enhanced system (about 80 %). The main removal product of NH 4 + -N was identified as the environmentally friendly gas of N 2 , although nitrate was also detected. Neutral pH condition was the optical pH for NH 4 + -N removal. Increasing reaction temperature, PMS dosage and Br - concentration were beneficial to accelerating the removal of NH 4 + -N. Cations of Cu 2+ and Fe 3+ , anions of SO 4 2- , CO 3 2 - and NO 3 - , humic acid and the actual water matrix of landfill leachate negligibly influenced the removal of NH 4 + -N, while Cl - exhibited strong enhancement on NH 4 + -N removal. In summary, this study provided an effective method to improve the oxidizing capacity of thermal/PMS system, especially for NH 4 + -N removal in wastewater containing Br - .
研究领域:
环境科学
·
污水处理
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Dandan Ma,Zhonghan Cheng,Ye Yuan,Somboon Chaemchuen
The zeolitic-imidazole frameworks (ZIFs) have become popular due to their uniformly structured cavities and portals of framework dimensions, which make them suitable for numerous applications. In order to access pores and functional surfaces, thermal activation is significantly post-treatment on the synthesis of ZIFs for their applications. This study explores the impact of different thermal activation conditions on two- to three-dimensional ZIFs, which significantly affect their structure, morphology, and properties. Their transform structure is evidenced by integrated X-ray diffraction technique , Thermogravimetric analysis , Scanning electron microscope, and Fourier transform infrared spectroscopy . Moreover, the performance of greenhouse gas adsorption (CO 2 and CH 4 ) applications is affected by the transformation through the thermal activation of materials. Therefore, understanding the activated conditions that impact material synthesis is crucial to maximizing the potential applications of ZIFs in various fields. The 2D ZIF-L has more exposed external surfaces and open structures, which makes it more reactive towards adsorptive reactants, unlike the 3D ZIFs. The 3D ZIFs have a robust structure and a higher porosity framework that can withstand challenging application conditions. Thus, it's essential to ensure appropriate activation conditions to maintain the functional properties of ZIFs, which are crucial for their optimal performance in various applications.
研究领域:
材料科学
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化学工程
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环境科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Chen-Yan Hu,Yuan-Zhang Hou,Yi-Li Lin,Yan-Guo Deng,Shuang-Jing Hua,Yi-Fan Du,Chiu-Wen Chen,Chung-Hsin Wu
In this study, we investigated the degradation kinetics of a commonly used iodinated contrast medium, iohexol, by using heat-activated persulfate. The results indicate that the iohexol concentration can be effectively reduced with a removal percentage higher than 85% despite the long reaction time (2–3 h). The iohexol disappearance fitted well with the pseudo-first-order kinetic model. The persulfate consumption almost reached the maximum value during the initial 5 min of the reaction. Subsequently, persulfate was no longer consumed, which resulted in a decrease in the reaction rate. The pseudo-first-order rate constant of iohexol degradation significantly increased with temperature but decreased with an increase in pH from 5 to 9. The results of the quenching experiments performed using ethanol and tert-butanol indicate that the role of hydroxyl radicals was more important than that of sulfate radicals in iohexol degradation during heat-activated persulfate oxidation. However, without heat activation, persulfate did not react with iohexol. Therefore, the effect of pH on the HO· concentration dominated the effect of pH on iohexol degradation. High concentrations of bicarbonate (≥5 mM), chloride (≥1 mM), and dissolved natural organic matter (≥5 mg/L) inhibited the degradation of iohexol due to the consumption of sulfate and hydroxyl radicals. The mineralization percentage was only 3.8% (no considerable improvement) when the temperature was increased to 80 °C. The molecular structures of the intermediates contained iodine with molecular weights higher than 377 Da. Moreover, the generation of iodide was detected. The experimental results suggest that special attention should be paid to the risk of the formation of disinfection by-products in the subsequent chlorine disinfection process when treating natural water containing iohexol through heat-activated persulfate oxidation.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2015
·
IF 2.002
Guangyan Tian,Wenbo Wang,Yuru Kang,Aiqin Wang
Herein, palygorskite (PAL) was activated via a simple hydrothermal process in the presence of ammonium sulfide, and the effects of activation on the microstructure, physico-chemical feature and adsorption behaviors of PAL were intensively investigated. The hydrothermal process evidently improved the dispersion of PAL crystal bundles, increased surface negative charges and built more active –Si–O − groups served as the new “adsorption sites”. The adsorption property of the activated PAL for Methyl Violet (MV) was systematically investigated by optimizing the adsorption variables, including pH, ionic strength, contact time and initial MV concentration . The activated PAL exhibited a superior adsorption capability to the raw PAL for the removal of MV (from 156.05 to 218.11 mg/g). The kinetics for MV adsorption followed pseudo second-order kinetic models, while the isotherm and thermodynamics results showed that the adsorption pattern well followed the Langmuir model. The structure analysis of PAL before and after adsorption demonstrated that electrostatic interaction and chemical association of –X–O − are the prominent driving forces for the adsorption process.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Processes
·
2022
·Vol. 10
·期 5
·941
·
IF 3.352
Yixin Lu,Yujie Liu,Chenghan Tang,Jiao Chen,Guo Liu
The degradation effect of heat/peroxymonosulfate (PMS) on atrazine (ATZ) is studied. The results show that the heat/PMS degradation for ATZ is 96.28% at the moment that the phosphate buffer (PB) pH, temperature, PMS dosage, ATZ concentration, and reaction time are 7, 50 °C, 400 μmol/L, 2.5 μmol/L, and 60 min. A more alkaline PB is more likely to promote the breakdown of ATZ through heat/PMS, while the PB alone has a more acidic effect on the PMS than the partially alkaline solution.HO•andSO4−•coexisted within the heat/PMS scheme, and ATZ quantity degraded byHO•andSO4−•in PB with pH = 7, pH = 1.7~1.HCO3−makes it difficult for heat/PMS to degrade ATZ according to inorganic anion studies, whileCl−andNO3−accelerate the degradation and the acceleration effect ofNO3−is more obvious. The kinetics of ATZ degradation via heat/PMS is quasi-first-order. Ethanol (ETA) with the identical concentration inhibited ATZ degradation slightly more thanHCO3−, and both of them reduced the degradation rates of heat/PMS to 7.06% and 11.56%. The addition ofCl−andNO3−increased the maximum rate of ATZ degradation by heat/PMS by 62.94% and 189.31%.Keywords:heat activation;PMS;atrazine;degradation mechanism;kinetics
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Bingxuan Ji,Muhammad Bilal Asif,Zhenghua Zhang
Membrane distillation (MD) has demonstrated its efficacy for seawater desalination, which prompted researchers to investigate its performance for the treatment of surface water containing natural organic matter (NOM). However, membrane fouling remains a significant technological constraint in the acceptability and implementation of MD modules. Herein, for the first time, a photothermally-activated PMS pre-treatment process is coupled to a direct contact (DC)-MD module for effective membrane fouling control. Photothermally-activated PMS (2 mM) pre-treatment achieved 69 % of UV 254 removal and 30.9 % of dissolved organic carbon removal and allowed stable operation of the DCMD without any reduction in water permeance vs 50 % reduction obtained without the pretreatment step. The analysis of NOM fractions after pre-treatment using Parallel Factor Analysis and molecular weight distribution indicated changes in NOM composition, which facilitated membrane fouling control. The photothermally-activated PMS pre-treatment seems to alleviate membrane fouling by limiting the foulant-membrane interaction, which was observed to result in the formation of the fouling layer containing aromatic proteins, microbial byproducts-like substances, and inorganic ( e.g., calcium) foulants. Finally, characterization of the used MD membranes revealed that the MD membrane properties could be kept unchanged by the photothermally-activated PMS pre-treatment step, thereby making the integrated DCMD system sustainable and attractive for widespread applications.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Chunsheng Ding,Zhiyue Cai,Chenkai Hu,Jia Lei,Lei Wang,Qingsong Li,Xueyan Li,Jing Deng
Pharmaceutical and personal care products (PPCPs) pose a great threat to water environment security. In this study, acyclovir (ACV) was efficiently degraded by thermally activated persulfate (TAP) system. The ACV degradation increased with rising reaction temperature and persulfate dosage. With the existence of inorganic anions and humic acid , ACV removal was retarded to varying degrees. Under strong alkaline condition, it was observed that the degradation of ACV was significantly inhibited. In addition, Kintecus software was employed to simulate ACV removal and achieved a good fit with the experimental results. The contribution rates of main reactive radicals under acidic, neutral, and alkaline conditions were investigated, and the contribution of hydroxyl radical (⋅OH) increased significantly under alkaline condition. The main active species were identified as sulfate radical (SO 4 ⋅ - ) and ⋅OH through quenching experiment, and the second-order reaction rate constants of SO 4 ⋅ - and ∙OH reacted with ACV were calculated to be 9.17 × 10 9 M −1 s −1 and 2.74 × 10 9 M −1 s −1 , respectively. The main degradation pathways included addition of free radicals, oxidation of branch chain and ring opening. The acute and chronic toxicity of intermediates to organisms predicted by ECOSAR were significantly reduced compared with that of ACV.
研究领域:
环境科学
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Yanxiang Zhang,Huiling Liu,Yanjun Xin,Yunpeng Shen,Jing Wang,Chen Cai,Mengmeng Wang
Erythromycin mycelial dreg (EMD) is a bio-fermentation residue of the pharmaceutical industry that may be used as a nutrient resource. However, the contaminants present in EMD need to be considered and controlled at an acceptable level prior to utilization. In this study, heat-activated persulfate (PS) oxidation of EMD was developed to degrade the residual erythromycin (ERY) and inactivate the ERY-resistant genes. The effects of temperature, initial PS concentration, and pH on the removal of ERY in EMD were studied. The results revealed that 99.0% ERY was degraded by 25 g PS/kg EMD under 80 °C within 120 min. The apparent rate constant ( k app ) in the acidic condition was higher than that in the alkaline condition. The contribution of sulfate radical ( SO 4 · - ) and hydroxyl radical (HO ) on ERY removal in EMD was found to be 36.8% and 29.4%, respectively. Six intermediate products (IPs) of ERY were clarified, and total organic carbon (TOC) was efficiently reduced by 99.4%. Finally, the detected ERY-resistant genes ere(B), erm(A), and erm(B) obviously presented a reduction during the heat-activated PS oxidation process.
研究领域:
环境科学
·
微生物学
·
药学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）