SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Si-Yu Duan,Xue Chen,Huang Huang,Xin Yang,Xin Lu
The formation of nitrogenous disinfection byproducts (N-DBPs) occurs in chloraminated water in drinking water distribution systems and may be affected by metal pipe materials and their corrosion products. The effect of copper corrosion products, including Cu 2+ , CuO, and Cu 2 O, on the formation of dichloroacetonitrile (DCAN) and dichloroacetamide (DCAcAm) was investigated during chloramination of natural organic matter (NOM), model precursors (carboxylic acids and amino acids), and real water samples. Copper corrosion products enhanced DCAN and DCAcAm formation during chloramination of NOM by 33%–72% and 11%–80%, respectively. Addition of 15 N-labeled monochloramine showed that the copper corrosion products primarily enhanced the formation of DCAN using organic nitrogen and monochloramine as nitrogen sources, and the formation of DCAcAm using monochloramine as the nitrogen source, but had a limited impact on the formation of DCAcAm using organic nitrogen as the nitrogen source. A distinct N-DBP formation pathway in the presence of Cu 2+ and CuO was observed using tyrosine as a model compound, which included the formation of 1,4-benzoquinone as a dominant intermediate. On reaction with monochloramine, the 1,4-benzoquinone greatly contributed to enhancement of DCAN and DCAcAm formation using monochloramine as the nitrogen source. During chloramination of real water samples, Cu 2+ and CuO enhanced DCAN formation by 9–40% and DCAcAm formation by 16–33%. This study increases our knowledge of copper catalyzed DCAN and DCAcAm formation in copper pipes, which will be meaningful for water safety in distribution systems using chloramine disinfection.
研究领域:
环境科学
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公共卫生
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产品关联
DOI
PubMed
高影响因子
CHEMICAL PAPERS
·
2013
·Vol. 67
·期 5
·517-525
·
IF 0.879
Wu Xing,Yi Jian-Min,Liu Yue-Jin,Liu Yong-Bing,Zhang Pan-Liang
The rapid expansion of a supercritical solution (RESS) process represents an attractive prospect for producing sub-micron and nano-particles of medical compounds with low solubility. The solubility of phenacetin in supercritical carbon dioxide was measured by the analytical-isothermal method at pressures ranging from 9.0 MPa to 30.0 MPa and temperatures ranging from 308.0 K to 328.0 K. The results show that the mole fraction solubility of phenacetin in supercritical carbon dioxide is up to 10 −5 . Four density-based semi-empirical models were introduced to correlate the experimental data. Agreement between the model predictions and experimental data is greater with the Adachi-Lu-modified Chrastil model than with the Chrastil model, Méndez-Santiago-Teja model, and the Bartle model and the average absolute relative deviation (AARD) observed is 0.0483. The preparation of fine phenacetin particles by the RESS process under different conditions of extraction temperatures (308.0–328.0 K), extraction pressures (9.0–30.0 MPa), nozzle temperatures (373.0–393.0 K), nozzle diameters (0.1–0.8 mm), and collection distance (20.0–40.0 mm) was investigated. The size and morphology of the resultant particles were analysed by SEM. A remarkable modification in size and morphology can be obtained by condition-optimisation.
研究领域:
药学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Yajun Li,Junjia Chen,Kui Wu
The knowledge of solid-liquid equilibrium data and solution thermodynamics of 2,2,2-trichloroacetamide (TCAcAm) in different solvents are essential for its synthesis, purification and further theoretical studies. In this paper, the solubility of TCAcAm in fifteen mono solvents of methanol, ethanol, n -propanol, isopropanol, n -butanol, isobutanol , n -pentanol, isopentanol, 2-butanone, acetone, ethyl acetate , 2-pentanone, acetonitrile , methyl acetate and ethyl formate was obtained through a gravimetric method at the temperature from 272.15 to 324.15 K under ambient pressure. The mole fraction solubility of TCAcAm in mono solvents showed an increasing trend with increasing temperature, and the phase equilibrium data in ketones and esters was much larger than that in alcohols. The experimental solubility can be well correlated using several thermodynamic models, such as the modified Apelblat equation, λh equation, non-random two-liquid (NRTL) model and the Wilson model. The obtained maximum relative average deviation ( RAD ) and root-mean-square deviation ( RMSD ) were 6.02 × 10 −3 and 2.086 × 10 −3 respectively. Besides, the dissolution enthalpy, entropy, and Gibbs free energy were calculated on the basis of thermodynamic relations and the Wilson model, which revealed that the dissolution of TCAcAm was a spontaneous and endothermic process.
研究领域:
化学工程
·
物理化学
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产品关联
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2014
·Vol. 8
·期 3
·312-319
·
IF 0
Tan Ming,He Gaohong,Dai Yan,Wang Rujie,Shi Wenhua
The ternary phase diagrams of polyetherimide (PEI)/ N,N -dimethylacetamide (DMAc) with H 2 O and BuOH as non-solvent were simulated using solubility parameter and Flory-Huggins theory. The phase diagrams show that 5.5% H 2 O/BuOH system containing 5% BuOH and 0.5% H 2 O, or 6.5% H 2 O/BuOH system containing 6.2% BuOH and 0.3% H 2 O is required to induce liquid-liquid demixing for 20 wt-% PEI/DMAc casting solution. Therefore, BuOH can enhance the phase separation of the PEI casting solution and hereby induce higher porosity of the membrane, and the diffusion of BuOH into the water coagulation bath causes larger pore size easily compared with DMAc. Our predictions that the membrane pure water flux first increases then decreases, and the rejection ratio of bovine serum albumin decreases with the increasing concentration of BuOH were validated by the experiments using the prepared membranes.
研究领域:
材料科学
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膜技术
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化学工程
✓ 已验证
DOI
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 29
·14634-14643
·
IF 11.301
Chuan-Shu He,Rong-Rong Ding,Guan-Nan Zhou,Di He,Peng Fan,Xiao-Hong Guan,Yang Mu
Surface passivation is one of the most challenging aspects in the successful application of zero-valent iron (ZVI) for water decontamination, especially when oxygen is inevitably present. This study found that the coexistence of HA ranging from 0 to 40.0 mg-C/L appreciably improved the pseudo-first-order kinetic rate constant of pollutant diatrizoate (DTA) reduction by ZVI from 0.0454 to 0.1365 h−1 under aerobic conditions. For the first time, it revealed that the coexistence of HA could accelerate the reductive removal of organic contaminants via ZVI surface depassivation rather than the previously proposed electron-shuttle mechanism under aerobic conditions. Interestingly, both DTA removal and Fe0 consumption were found to undergo two stages in the presence of HA, with an initial slight enhancement attributed to the Fe(III)–HA complex formation partially suppressing iron precipitation, followed by a remarkable promotion arising from the HA-associated iron oxide detachment from the Fe0 surface. These findings not only provide a good strategy to enhance ZVI reactivity with minimal extra cost and complexity under aerobic conditions, but also help understand the ZVI behavior in practical applications.
研究领域:
环境科学
·
污染治理
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DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Zeming Wang,Li Liu,Yeqing Lan,Wei Li
Discarded cigarette butts, a kind of abandoned waste, have posed a threat to environments. Nevertheless, they are also an available carbon source serving as adsorbents. On the other hand, antibiotic overuse has brought potential risks to natural organisms. In this study, a novel adsorbent via anchoring zero valent tin (Sn 0 ) onto carbon derived from cigarette butts (Sn-CCB) was obtained to enhance the removal of antibiotic phenacetin (PNT) from aqueous solution. A series of characterizations were conducted to investigate the physical and chemical properties of Sn-CCB. Sn was proved to exist in the species of Sn 0 , which was uniformly distributed on the surface of the CCB material. Compared with CCB material, Sn-CCB possessed more excellent performance in three aspects below: (1) 70% growth of BET surface area (458 m 2 g −1 vs . 273 m 2 g −1 ); (2) 2.2 times of the maximum adsorption capacity (156.4 mg g −1 vs . 71.3 mg g −1 ); and (3) better hydrophilicity. The fitting results of pseudo-second-order kinetic model and FTIR spectra confirmed that the removal of PNT by Sn-CCB was chemisorption . Langmuir equation was more suitable to describe the adsorption of PNT with r 2 = 0.9989, indicating the mono-layer sorption . The feasibility of practical application was also assessed. The adsorbent exhibited excellent stability and reusability, and the maximum adsorption capacity still maintained 150.2 mg g −1 even after the fifth cycle. Coexisting ions (Cl - , HCO 3 - , and NO 3 - ), humic acid , and realistic water matrix all exerted humble effect on the adsorption of PNT. Furthermore, our results confirmed that Sn-CCB as an adsorbent for the removal of PNT in a column reactor was feasible.Therefore, this study provides us with an innovative strategy to prepare potential adsorbents using cigarette butts as a recycled material for the removal of antibiotics from aqueous solution.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2016
·
IF 2.208
Xingdu Chen,Chengjian Yang,Weiwei Wang,Bizhou Ge,Jun Zhang,Yucan Liu,Yaping Nan
The biodegradation characteristic and potential metabolic pathway for removal of environmental N,N-dimethylacetamide (DMAC) by Rhodococcus sp. strain B83 was studied. Rhodococcus sp. strain B83 was isolated from the rhizosphere of a pagoda tree and proved capable of utilizing DMAC as sole source of carbon and nitrogen. Batch culture studies showed that strain B83 could tolerate up to 25 g/L DMAC and showed distinct growth on possible catabolic intermediates except for acetate. The nitrogen balance analysis revealed that approximately 71% of the initial nitrogen was converted to organic nitrogen. DMAC degradation has led to accumulation of acetate and organic nitrogen, meanwhile traces of nitrate and ammonia was build-up but without nitrite. The growth of strain B83 could be inhibited by adding exogenous acetate. By means of the assay of enzymatic degradation of DMAC, several catabolic intermediates at different intervals were observed and identified. Based on the results obtained from culture solution and enzymatic degradation assay, a detailed pathway is proposed for DMAC biodegradation.
研究领域:
环境微生物学
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生物修复
·
生物降解
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 40
·24836-24842
·
IF 3.361
Yunping Zhoujin,Mingtao Zhang,Sean Parkin,Tonglei Li,Faquan Yu,Sihui Long
A new solvate of clonixin (CLX), a dimethylacetamide (DMA) solvate, has been obtained by crystal growth in DMA. The new form was characterized by NMR, single-crystal X-ray diffraction, and PXRD. The crystal structure is stabilized by a strong hydrogen bond between the carboxylic acid OH of CLX and the DMA carbonyl, the strength of which is on par with those of the four solvent-free forms of CLX and the DMF solvate. These previously known forms are based on either the acid–acid homosynthon or the acid–pyridine heterosynthon, depending on the dihedral angle between the two aromatic rings of CLX, or the heterodimer between CLX and DMF. The new solvate loses DMA to convert into form I of CLX, as confirmed by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD), similar to how the DMF solvate does. A comparison of the two solvates was carried out and theoretical studies were performed to shed light on the conformational difference between the two CLX molecules in the two solvates and the packing differences between them. The insight gained on this solvatomorphic system could aid the design of new solvates and cocrystals of CLX.
研究领域:
药物化学
·
晶体学
·
材料科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2018
·
IF 3.927
Huang Huang,Kai-Li Shao,Si-Yu Duan,Chu-Ying Zhong
The catalytic effect of copper corrosion products, including copper ions , cupric oxide, and cuprous oxide, on the formation of haloacetamides and haloacetonitriles during chlorination of natural organic matter (NOM), model nitrogenous precursors, and real water samples was investigated. During chlorination of NOM, the presence of these copper corrosion products facilitated chlorine decay, and enhanced the formation of dichloroacetonitrile (DCAN) and dichloroacetamide (DCAcAm) with enhancement ratios of 45–59% and 64–137% after 10 h contact time, respectively. Six amino acids were selected as nitrogenous NOM surrogates for chlorination, and the results show that the enhancement of DCAN and DCAcAm formation by copper corrosion products was only observed for slow reacting amino acids, including glutamine, glutamic acid, and phenylamine , suggesting that copper corrosion products may enhance DCAN and DCAcAm formation by catalyzing NOM portions that are relatively inefficient precursors. When bromide and copper corrosion products were present, the formation of dihaloacetonitriles (DHANs) and dihaloacetamides (DHAcAms) could be enhanced during chlorination of NOM, but the degrees of bromine substitution for DHANs and DHAcAms decreased. Although copper corrosion products facilitated DHAN and DHAcAm hydrolysis with the facilitation increasing as the halogens shifted from chlorine to bromine, increased DHAN and DHAcAm concentrations was observed during chlorination of real water samples in the presence of copper corrosion products, confirming that the copper corrosion products had a catalytic effect on DHAN and DHAcAm formation that exceeded their catalytic effect on DHAN and DHAcAm hydrolysis. This study provides basic knowledge of disinfectant residuals and the fate of haloacetonitriles and haloacetamides in drinking water distribution systems where copper is used, which will be helpful for the management of safe water distribution.
研究领域:
环境科学
·
水处理工程
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DOI
高影响因子
Journal of Thermal Science
·
2024
·Vol. 33
·期 4
·1564-1576
·
IF 1.8
An Zhoujian,Hou Wenjie,Du Xiaoze,Huang Zhongzheng,Mombeki Pea Hamir Johan,Zhang Dong,Liu Xiaomin
Phase change materials (PCMs) are a kind of highly efficient thermal storage materials which have a bright application prospect in many fields such as energy conservation in buildings, waste heat recovery, battery thermal management and so on. Especially inorganic hydrated salt PCMs have received increasing attention from researchers due to their advantages of being inexpensive and non-flammable. However, inorganic hydrated salt PCMs are still limited by the aspects of inappropriate phase change temperature, liquid phase leakage, large supercooling and severe phase separation in the application process. In this work, sodium acetate trihydrate was selected as the basic inorganic PCM, and a novel shape-stabilized composite phase change material (CPCM) with good thermal properties was prepared by adding various functional additives. At first, the sodium acetate trihydrate-acetamide binary mixture was prepared and the melting point was adjusted using acetamide. Then the binary mixture was incorporated into expanded graphite to synthesize a novel shape-stabilized CPCM. The thermophysical properties of the resultant shape-stabilized CPCM were systematically investigated. The microscopic morphology and chemical structure of the obtained shape-stabilized CPCM were characterized and analyzed. The experiment results pointed out that acetamide could effectively lower the melting point of sodium acetate trihydrate. The obtained shape-stabilized CPCM modified with additional 18% (mass fraction) acetamide and 12% (mass fraction) expanded graphite exhibited good shape stability and thermophysical characteristics: a low supercooling degree of 1.75°C and an appropriate melting temperature of 40.77°C were obtained; the latent heat of 151.64 kJ/kg and thermal conductivity of 1.411 W/(m·K) were also satisfactory. Moreover, after 50 accelerated melting-freezing cycles, the obtained shape-stabilized CPCM represented good thermal reliability.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2018
·
IF 7.051
Shunke Ding,Feifei Wang,Wenhai Chu,Zhongqi Cao,Yang Pan,Naiyun Gao
The effective removal of haloacetamides (HAMs) as a group of emerging disinfection by-products is essential for drinking water safety. This study investigated the degradation of 10 HAMs, including chlorinated, brominated, and iodinated analogues, by sodium sulfite (S(IV)) and the mechanism behind it. The results indicated that all HAMs, excluding chlorinated HAMs, decomposed immediately when exposed to S(IV). The reductive dehalogenation kinetics were well described by a second-order kinetics model, first-order in S(IV) and first-order in HAMs. The degradation rates of HAMs increased with the increase of pH and they were positively correlated with sulfite concentration, indicating that the reaction of S(IV) with HAMs mainly depends on sulfite. The rank order and relative activity of the reaction of sulfite with HAMs depends on bimolecular nucleophilic substitution reaction reactivity. The order of the reductive dehalogenation rates of HAMs versus the substitution of halogen atoms was iodo- > bromo- >> chloro-. During reductive dehalogenation of HAMs by sulfite, the α-carbon bound to the amide group underwent nucleophilic attack at 180° to the leaving group (halide). As a consequence, the halide was pushed off the opposite side, generating a transition state pentacoordinate. The breaking of the C-X bond and the formation of the new C-S bond occurred simultaneously and HAM sulfonate formed as the immediate product. Results suggest that S(IV) can be used to degrade brominated and iodinated HAMs in drinking water and therefore should not be added as a quenching agent before HAM analysis to accurately determine the HAM concentrations produced during water disinfection .
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
WATER RESEARCH
·
2018
·
IF 7.051
Chao Fang,Stuart W. Krasner,Wenhai Chu,Shunke Ding,Tiantao Zhao,Naiyun Gao
Haloacetamides (HAMs), an emerging class of disinfection by-products, have received increasing attention due to their elevated cyto- and genotoxicity. However, only limited information is available regarding the iodinated analogues. This study investigated the formation and speciation of iodinated haloacetamides (I-HAMs) and their chlorinated/brominated analogues during the chloramination of bromide and/or iodide-containing waters and a model compound solution over various time periods. The rapid formation of diiodoacetamide (DIAM) was observed during chloramination of three simulated samples, whereas brominated (Br-HAMs) and chlorinated haloacetamides (Cl-HAMs) increased slowly with increasing reaction time. To further understand the differences in the formation of HAMs containing different halogens, experiments with the model compound asparagine in the presence/absence of iodide were conducted. Moreover, iodine utilisation factors and iodine incorporation factors were observed to increase significantly faster and were substantially higher than those of bromine. This implied that, compared with bromide, iodide has substantially greater potential to be transformed to the corresponding HAMs during chloramination, similar to that of other classes of DBPs. That is, I-HAMs formed faster than the other species investigated, including Cl-HAMs and Br-HAMs, in the early reaction stages (0–3 h). The effect of the bromide/iodide ratio (i.e., constant iodide, increasing bromide) on I-HAM formation was also examined. With increasing bromide/iodide ratio, the formation of Br-HAMs increased and dichloroacetamide decreased, but the formation of DIAM was largely unchanged. This was consistent with the constant level of iodide in spite of the increasing bromide. Chlorine and ammonia are applied separately during chloramination in water treatment , so the effect of pre-chlorination (before adding ammonia) on the formation and speciation of I-HAMs during in situ chloramination was also evaluated. Effective mitigation of DIAM formation with in situ chloramination was achieved, and the efficiency improved with increasing pre-chlorination time, where iodide was oxidised to iodate . The HAM-associated cytotoxicity was calculated to determine the change in toxicity at different reaction times, bromide/iodide ratios, and pre-chlorination times. A similar trend as the formation of I-HAMs was observed, which increased rapidly in the first 3 h, but decreased somewhat subsequently. When the bromide/iodide ratio and pre-chlorination time was increased, the calculated toxicity of the HAMs increased (due to more formation of Br-HAMs and less Cl-HAMs) and decreased (due to less DIAM formation), respectively.
研究领域:
环境科学
·
毒理学
✓ 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）