ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 28
·期 26
·35113-35125
·
IF 4.223
An Shaorong,Jin Qiang
In recent years, the excess discharge of ammonia nitrogen from wastewater into surface water has been regulated by more stringent standard. The air stripping method is successfully used to treatment of high-concentration ammonia nitrogen; however, alkali will be added to keep pH more than 10, which is costly and not environment-friendly operation. In this study, an advanced air stripping (AAS) based on foam separation of removing ammonia nitrogen in low concentration from aqueous solution at low pH was proposed. The effect of conditions such as air flow rate, temperature, SDS dosage, coexisting ionic strength, pH, and initial ammonia nitrogen concentration on the removal efficiency was studied. The advanced air stripping exhibited favorable removal efficiency for NH 4 + -N in low concentration from aqueous solution (20 mg·L −1 ) with a broad range of low pH 3.0–9.0. Besides, for strongly alkaline (pH=11.0) solution, the advanced air stripping can alleviate the decrease of pH to some extent and keep ammonia nitrogen stripping out continuously based on equilibrium shift between NH 4 + and NH 3 . A microcalorimeter was applied to demonstrate the interaction between the negatively charged hydrophilic groups of SDS and NH 4 + ions, helping to understand the mechanisms more clearly. The simple operation and the satisfactory removal efficiency could imply that the advanced air stripping is a promising technology for minimizing low-concentration NH 4 + -N. Graphical abstract
研究领域:
环境科学
·
废水处理
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Lei Wu,Hongyan Wu,Qiusi Wen,Jun Zhou,Ahmed M. Aljuwayie,Poh Wai Chia,Gan Ye,Qiuli Zhang,Rock Keey Liew,Su Shiung Lam
Thermal desorption technology at low temperatures has been extensively researched. However, the challenge remains in maintaining soil ecological function while effectively removing PAHs from contaminated soil using this method. Based on the gas hammer fragmentation concept, this study presents the strategy of gas stripping (steam extraction) coupled with microwave remediation. A multifunctional bluecoke-based modifier (MnO 2 /KHCO 3 @BC) was prepared followed by an investigation on the removal effect, soil characteristics and remediation mechanism of MnO 2 /KHCO 3 @BC-assisted microwave remediation of pyrene (PAHs model) contaminated soil. The research findings indicate that MnO 2 /KHCO 3 @BC is more effective in generating oxygen vacancies, facilitating surface electron transfer , and enhancing the oxidation effect of ROS on pyrene compared to KHCO 3 @BC and MnO 2 @BC. Despite having slightly inferior electromagnetic properties to BC, MnO 2 /KHCO 3 @BC could achieve a microwave remediation temperature of approximately 300 °C under optimal experimental conditions. MnO 2 /KHCO 3 @BC demonstrated remarkable pyrene removal efficiency with a maximum removal rate of 98.34%, making it an ideal candidate for pyrene remediation. Moreover, the remediated soil exhibited a weakly acidic nature, with a significant decrease in particle size and a substantial increase in potassium content. The study also highlighted a novel synergistic mechanism of ''microwave heating - gas stripping - oxidation,'' which can efficiently remove most of the pyrene adsorbed inside and outside of soil particles and degrade it into low-toxic and small-molecule organic matter, CO 2 , and H 2 O. Overall, the findings of this study could hold potential significance for upcoming endeavours concerning polluted industrial areas.
研究领域:
环境科学
·
土壤修复
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DOI
高影响因子
VACUUM
·
2023
·
IF 4
Pengfei Zhao,Guangshi Li,Ximu Chen,Peng Cheng,Yiming Yan,Zhongya Pang,Chenteng Sun,Xing Yu,Xingli Zou,Xionggang Lu
One of the greatest challenges for long-term human activities on the Moon is the development of in-situ resource utilization (ISRU) technologies, including in-situ oxygen extraction. In this study, a novel method called laser thermal vacuum metallurgy (LTVM) was proposed for oxygen extraction from lunar regolith , specifically using TiO 2 as raw material. Firstly, the theoretical feasibility of oxygen production from TiO 2 was elucidated through thermodynamic calculations. Subsequently, the impact of laser power density on the decomposition behavior of TiO 2 was investigated. The results demonstrate that through the augmentation of laser power density to elevate temperatures, there is a substantial enhancement observed in both the pyrolysis and vaporization processes of TiO 2 . Under the conditions of a laser power density of 2.48 kW/cm 2 , the surface temperature of TiO 2 can be maintained at approximately 2175 °C. The resulting pyrolysis products consist of Ti 6 O 11 (8.2 ± 0.5 wt %), Ti 5 O 9 (23.7 ± 0.6 wt %), Ti 4 O 7 (10.9 ± 0.4 wt %), and Ti 3 O 5 (57.2 ± 0.8 wt %). Further combining with the result of gas collection, the estimated oxygen extraction rate is approximately 43.3 L per kilogram of TiO 2 . Therefore, LTVM holds the potential to provide a new approach for in-situ oxygen extraction from titanium-containing lunar regolith on the Moon.
研究领域:
材料科学
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天体物理学
·
航天工程
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产品关联
DOI
高影响因子
Foods
·
2022
·Vol. 11
·期 16
·2502
·
IF 5.561
Huiting Wu,Yuyu Chen,Wanzhen Feng,Shanshan Shen,Yuming Wei,Huiyan Jia,Yujie Wang,Weiwei Deng,Jingming Ning
White tea (WT) is a slightly fermented tea, and withering is a critical step in its processing. The withering treatment can affect white tea’s aroma; different treatments’ effects were investigated in this study. White tea was withered indoors (IWT), in a withering-tank (WWT), or under sunlight (SWT). Quantitative descriptive analysis (QDA) results showed that SWT had a more obvious flower aroma, and WWT had a more pronounced grassy aroma. Volatile compounds were extracted and subsequently detected with solvent-assisted flavor evaporation (SAFE) and headspace solid-phase microextraction (HS-SPME) combined in addition to gas chromatography–mass spectrometry (GC-MS). A total of 202 volatile compounds were detected; 35 of these aroma-active compounds met flavor dilution (FD) factor ≥ 4 or odor activity value (OAV) ≥ 1. The nine key potent odorants for which both conditions were met weredimethyl sulfide,2-methyl-butanal,1-penten-3-one,hexanal,(Z)-4-heptenal,β-Myrcene, linalool, geraniol, and trans-β-ionone. These results were used with QDA to reveal that SWT had a stronger floral aroma mainly due to an increase of geraniol and linalool. Moreover, WWT had a stronger grassy aroma mainly due to increasedhexanal. The results could be used to select processing methods for producing white tea with a superior aroma.Keywords:white tea;withering treatment;volatile compounds;aroma extract dilution analysis;odor activity value
研究领域:
食品科学
·
茶叶加工学
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DOI
PubMed
高影响因子
Beverages
·
2020
·Vol. 6
·期 3
·42
·
IF 0
Zhe Wang,Xizhen Sun,Yuancai Liu,Hong Yang
The objective of this study was to investigate the aroma profile and major flavor compounds in Xiaoqu liquor by a combination of sensory profiling, GC-O/GC-MS analysis, and SBSE-GC-MS. A total of 57 important volatile compounds (FD ≥ 2) were screened based on the retention indices, aromatic characteristics, standard comparison, and aroma extract dilution analysis (AEDA). By calculating the odor activity values (OAVs), 32 aroma active compounds were identified in Xiaoqu liquor. In the aroma recombination experiments, these active compounds were dissolved in 46% ethanol water at their natural concentrations, resulting in successful simulations of the typical aromas of Xiaoqu liquor, including fruity aroma, sweet aroma, and grain aroma. Omission experiments showed that the critical compounds that contribute to the characteristic flavor of Xiaoqu liquor include ethyl octanoate, acetaldehyde, 1,1-diethoxyethane, isoamyl acetate, ethyl acetate, valeric acid, 1-octen-3-ol, and ethyl isovalerate. The results provide some guidance for upgrading the fermentation and microbial strain in the production of Xiaoqu liquor.Keywords:Xiaoqu liquor;aroma extract dilution analysis;odor activity value;sensory characterization;flavor compounds
研究领域:
食品科学
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微生物学
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产品关联
DOI
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Ziheng Li,Shenghan Ji,Fengting Yao,Yan Dai,Xuehua Ruan,Xiaobin Jiang,Wenji Zheng,Gaohong He
Covalent organic frameworks (COFs) are regarded as disruptive membrane materials owing to their versatile functionalities, high stability and ordered nanochannels. However, a major obstacle to the application of COF-based membranes in gas separation is the inherent size difference between their pore sizes and target gas molecules. Herein, we employed a confined cross-linking strategy to graft CO 2 -philic poly-ethyleneimine (PEI) onto carboxylic acid-type iCOF membranes, constructing a gradient wedge-shaped pore wall structure to enhance H 2 separation. High-density carboxyl group-containing iCOF nanosheets were prepared via an improved single-phase solution method and assembled into membranes. 1-ethyl-3-(3-dimethylami-nopropyl) carbodiimide/N-Hydroxysuccinimide (EDC/NHS) coupling chemistry was used to functionalize iCOF membranes with PEI. The introduction of a large number of amino groups via PEI enhances CO 2 adsorption by 81.4%. Meanwhile, the grafting of PEI reduces defects or pinholes on the membrane surface and improves the mechanical properties and stability. As a result, the PEI-functionalized iCOF@PEI-4 membrane exhibits a H 2 permeance of 1103 GPU and an H 2 /CO 2 selectivity of 21.3, positioning its performance among advanced membranes and surpassing the 2008 Robeson upper bound. Customized structural design of iCOF membranes through tailored functionalization may provide insights for designing molecularly selective COF membranes.
研究领域:
材料科学
·
膜分离技术
·
纳米材料
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化学工程
·
功能高分子
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产品关联
DOI
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 29
·20314-20320
·
IF 3.9
Han Chen,Yuanming Li,Zanyun Ying,Yinfeng Xia,Juping You
Microbial fuel cells (MFCs) are widely acknowledged to be a promising eco-friendly abatement technology of pollutants, and are capable of generating electricity. However, the poor mass transfer and reaction rate in MFCs significantly decrease their treatment capacity for contaminants, especially hydrophobic substances. The present work developed a novel MFC integrated with an airlift (ALR) reactor using a polypyrrole modified anode to promote the bioaccessibility of gaseous o-xylene and attachment of microorganisms. The results indicated that the established ALR-MFC system showed excellent elimination capability, with removal efficiency exceeding 84% even at high o-xylene concentration (1600 mg m−3). The maximum output voltage of 0.549 V and power density of 13.16 mW m−2 obtained by the Monod-type model were approximately twice and sixfold higher than that of a conventional MFC, respectively. According to the microbial community analysis, the superior performances of the ALR-MFC in terms of o-xylene removal and power generation were mainly ascribed to the enrichment of degrader (i.e. Shinella) and electrochemical active bacteria (i.e. Proteiniphilum). Moreover, the electricity generation of the ALR-MFC did not decrease at a high O2 concentration, as O2 was conducive to o-xylene degradation and electron release. The supplication of an external carbon source such as sodium acetate (NaAc) was conducive to increasing output voltage and coulombic efficiency. The electrochemical analysis revealed that released electrons can be transmitted with the action of NADH dehydrogenase to OmcZ, OmcS, and OmcA outer membrane proteins via a direct or indirect pathway, and ended up transferring to the anode directly.
研究领域:
环境科学
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微生物学
·
电化学
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产品关联
DOI
PubMed
高影响因子
Foods
·
2025
·Vol. 14
·期 16
·2759
·
IF 5.1
Mingming Zhang,Zhihui Feng,Fang Wang,Jianxin Chen,Yifan Li,Yuqiong Chen,Junfeng Yin
Appropriate aroma extraction methods are crucial prerequisites for accurately and objectively characterizing the authentic aroma profile of samples. Purified water and ionized water were used as brewing water, and the effects of different tea-to-water ratios, extraction temperatures, and extraction times on the aroma authenticity and component enrichment of tea infusions were compared. The conditions of a tea-to-water ratio of 1 g:10 mL, extraction at 30 °C for 30 or 45 min were identified as the optimal parameter range, which could maximize the enrichment of aroma while maintaining fidelity. The cosine value of the aroma attribute scores between the optimal parameter set and the control group (tea brewed at 1 g:10 mL ratio for 4 min) exceeded 0.979, and the correlation coefficient surpassed 0.828. Test evaluation results indicate the method had good reproducibility and effectively highlighted the differential impacts of ionic content in brewing water on tea aroma constituents. This approach effectively solved the problem of sensory distortion caused by conventional high-temperature and long-duration extraction, enabling precise analysis of how water quality authentically influences tea infusion aroma characteristics.
研究领域:
食品科学
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分析化学
·
感官科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
·
2025
·
IF 3.1
Lingling Zhang,Yi Liu,Xinyi Du,Di Zhu,Zhe Shi,Mang Lin,Biao Jin
Chlorinated organic compounds (COCs) are industrially produced for different applications. These chemicals occur as common organic contaminants in soil and groundwater. Compound specific isotope analysis (CSIA) has been widely applied to delineate underlying transformation processes of organic contaminants. However, it remains unclear how volatilization processes would influence observed CSIA signals of different COCs, which is of special interest for remediation techniques such as soil vapor extraction and soil bioventing that rely on volatilization. To fill this data gap, our study developed an experimental setup and applied our optical CSIA approach to resolve carbon isotope fractionation of 12 different COCs during volatilization. Inverse carbon isotope fractionation was observed for all the target compounds, where positive carbon isotope enrichment factors (ε) were obtained. The extent of carbon isotope fractionation was correlated with the elemental compositions of the target compounds, indicating that chlorine substitutions lead to more pronounced inverse carbon isotope effects. Our study widened applications of the optical carbon CSIA method, and provided valuable data to evaluate volatilization-induced carbon isotope fractionation of different COCs.
研究领域:
环境科学
·
地球化学
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产品关联
DOI
高影响因子
JOURNAL OF FOOD PROCESSING AND PRESERVATION
·
2019
·Vol. 43
·期 5
·e13933
·
IF 1.288
Dandan Pu,Huiying Zhang,Yuyu Zhang,Baoguo Sun,Fazheng Ren,Haitao Chen
The aroma compounds in four brands of white bread were characterized by aroma extraction dilution analysis, quantitation, aroma recombination, and omission tests. A total of 54 aroma compounds were detected. Among them, methional had the highest flavor dilution (FD) factor of 729, followed by ( E,E )-2,4-decadienal (FD = 243), furaneol (FD = 243), and δ -decalactone (FD = 243). Thirty-nine compounds (FD ≥ 9) were quantitated then analyzed by odor activity values (OAVs), 31 of which had OAVs ≥ 1. Four recombination models showed a similarity of 90.35% to the corresponding white bread samples. Omission tests confirmed that ( E,E )-2,4-decadienal (OAV = 1,229), 4-methyl-5-thiazoleethanol (OAV = 274), δ -decalactone (OAV = 70), furaneol (OAV = 40), 2-phenylethanol (OAV = 20), and methional (OAV = 12) were the key aroma compounds in white bread. Additionally, the alcohols and acids also significantly ( p < 0.001) contributed to the sour, sweet, and flour-like notes of white bread. Practical applications In this work, the key aroma compounds of white bread were confirmed. The content of aromas was significantly different among four brands of white bread with different recipes and processing techniques. These results provide an important theoretical basis for the improvement of quality control and processing of white bread.
研究领域:
食品科学
·
分析化学
·
感官评价
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产品关联
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2019
·
IF 3.579
Zhihui Feng,Ming Li,Yifan Li,Xiaochun Wan,Xiaogen Yang
The orchid-like odor of a tea infusion is regarded as a noble aroma and an essential sensory attribute for certain premium teas. Such tea leaves are difficult to make and the quality is not always reproducible. This study is focused on the molecular sensory basis of the orchid-like attribute in tea brews. The aroma is defined as jasmine- and magnolia-like floral notes with a fruity undertone and found to be closely related to the flower scent of the orchid Cymbidium faberi Rolfe (hui lan) by a sensory panel. Gas chromatography mass spectrometry (GC-MS) and aroma extract dilution analysis revealed that the key contributor was (Z)-methyl epijasmonate (epi-MeJA), which was also one of the main odor compounds in the flower scent of C. faberi and in the infusions of selected high-quality teas. Concentration of epi-MeJA was ranging from 0.09 to 2.2 µg/g in the oolong and green tea leaves.
研究领域:
食品科学
·
分析化学
·
农学
·
植物科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Qian Li,Zhenghua Guo,Shining Geng,Manyu Wen,Jiahui Wang,Liang Yu
Helium (He) is a strategically scarce resource primarily occurring in helium-bearing natural gas. The generally low helium content in natural gas resources results in significant extraction challenges and high costs. Gas separation membrane technology offers an attractive opportunity for the cost-effective extraction of He from natural gas. Highly selective and permeable gas membranes are urgently needed to address the extremely low He concentration in natural gas mixtures. In this study, polysilsesquioxane (PSQ) membranes with ultramicropores (0.4–0.5 nm) were constructed via co -polymerization of an organic-rich precursor (bis3-(trimethoxysilyl)propylethylene diamine (BTPDA)) and another organic-lean precursor (1,2-bis(triethoxysilyl)ethane (BTESE)). Such a strategy led to the formation of a novel hybrid PSQ network structure, which possesses rigid network skeleton and flexible ultramicropores, allowing for the precise molecular sieving for separation of He from its mixtures. The resulted membranes displayed excellent structural stability, He permeability (>1570 GPU, measured with pure He) and He/CH 4 selectivity (>100) upon the optimization of the molar ratio of these two precursors during the sol-gel process. Compared to traditional PSQ membranes fabricated via homopolymerization of single precursor with either organic-rich or organic-lean properties, as well as other reported polymer and inorganic membranes, the membranes with tailored flexible ultramicropores tended to overcome the trade-off of He permeability and He/CH 4 selectivity, showing great promise for the industrial He extraction from natural gas field.
研究领域:
材料科学
·
化学工程
·
膜技术
·
气体分离
·
高分子化学
✓ 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）