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Behavior of aqueous stable colloidal nano-C

Jing HUO,Ye YU,Ling GE,Bo ZHANG,Yiliang HE

《环境科学与工程前沿（英文）》 2015年 第9卷 第2期   页码 197-205 doi: 10.1007/s11783-014-0624-6

摘要： C , as one of carbon nanomaterials widely used in various fields, could be released into the water environment thus exerting some potential health risks to human beings. This work examined the behavior of aqueous stable colloidal nano-C (nC ) aggregates under different environmental conditions including Polyethylene glycol octylphenol ether (TX100) micelles concentration, pH, and reaction time when exposed to TX100 micelles. Results show that the nC aggregates became more dispersive and restored the capability of generating the singlet oxygen when exposed to TX100 micelles. With the increase of TX100 concentration, smaller average size of nC aggregates was observed in dynamic light scattering (DLS) analysis, the fluorescence intensity of TX100 was more quenched by nC aggregates, and the kinetic rate constant of generating the singlet oxygen for nC aggregates was improved. The mean size of nC aggregates in the presence of TX100 had no obvious variations when the pH ranged from 4 to 8. The longer reaction time between nC aggregates and TX100 led to a higher kinetic rate constant of generating the singlet oxygen. Collective data suggest that variations in physicochemical properties of nC aggregates are strongly dependent on the surrounding media under different environmental conditions and directly govern nC ’s transport behavior and potential toxicity.

关键词： nano-C60 (nC60) aggregates     photochemical reactivity     artificial biological membrane    

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Parameter for judging reactivity of coal and coke

HE Hongzhou, LUO Zhongyang, CEN Kefa

《能源前沿（英文）》 2008年 第2卷 第3期   页码 354-358 doi: 10.1007/s11708-008-0052-z

摘要： To eliminate the judgment error of char reactivity arising from different carbon content of samples, a new parameter called specific maximum weight loss rate was introduced. It is defined as the quotient of the maximum weight loss rate in non-isothermal thermogravimetric analysis (TGA) experiment to the carbon content of the corresponding sample. The reactivity of different kinds of coal, the reactivity of the same coal type with different lithotype, and the reactivity of the char with different carbon conversion rates were checked by using the specific maximum weight loss rate, and the results were analyzed and compared with those obtained by using other criteria. The results show that the specific maximum weight loss rate can be used as a commonality parameter to evaluate and distinguish the reactivity of different coal and char. The heating rate selected in TGA experiment has no effect on the judgment.

关键词： thermogravimetric analysis     specific maximum     different lithotype     experiment     TGA experiment    

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Surface modification of biomaterials by photochemical immobilization and photograft polymerization to

Yakai FENG, Haiyang ZHAO, Li ZHANG, Jintang GUO,

《化学科学与工程前沿（英文）》 2010年 第4卷 第3期   页码 372-381 doi: 10.1007/s11705-010-0005-z

摘要： Thrombus formation and blood coagulation are serious problems associated with blood contacting products, such as catheters, vascular grafts, artificial hearts, and heart valves. Recent progresses and strategies to improve the hemocompatibility of biomaterials by surface modification using photochemical immobilization and photograft polymerization are reviewed in this paper. Three approaches to modify biomaterial surfaces for improving the hemocompatibility, i.e., bioinert surfaces, immobilization of anticoagulative substances and biomimetic surfaces, are introduced. The biomimetic amphiphilic phosphorylcholine and Arg-Gly-Asp (RGD) sequence are the most effective and most often employed biomolecules and peptide sequence for improving hemocompatibility of material surfaces. The RGD sequence can enhance adhesion and growth of endothelial cells (ECs) on material surfaces and increase the retention of ECs under flow shear stress conditions. This surface modification is a promising strategy for biomaterials especially for cardiovascular grafts and functional tissue engineered blood vessels.

关键词： biomimetic amphiphilic     amphiphilic phosphorylcholine     endothelial     functional     biomaterial    

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Identification of sources, characteristics and photochemical transformations of dissolved organic matter

《环境科学与工程前沿（英文）》 2021年 第15卷 第5期 doi: 10.1007/s11783-020-1340-z

摘要：

• The source of DOM in surface water and sediment is inconsistent.

关键词： Dissolved organic matter     Parallel factor analysis     Excitation-emission matrices     Photodegradation    

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Effects of different types of biochar on the properties and reactivity of nano zero-valent iron in soil

《环境科学与工程前沿（英文）》 2021年 第15卷 第5期 doi: 10.1007/s11783-021-1388-4

摘要：

• Biochar enhanced the mobility and stability of zero-valent iron nanoparticles.

关键词： Nano zero-valent iron     Biochar     BDE209     Transport     Soil    

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Nanostructure and reactivity of soot from biofuel 2,5-dimethylfuran pyrolysis with CO

Lijie ZHANG, Kaixuan YANG, Rui ZHAO, Mingfei CHEN, Yaoyao YING, Dong LIU

《能源前沿（英文）》 2022年 第16卷 第2期   页码 292-306 doi: 10.1007/s11708-020-0658-3

摘要： This paper investigated the nanostructure and oxidation reactivity of soot generated from biofuel 2,5-dimethylfuran pyrolysis with different CO additions and different temperatures in a quartz tube flow reactor. The morphology and nanostructure of soot samples were characterized by a low and a high resolution transmission electron spectroscopy (TEM and HRTEM) and an X-ray diffraction (XRD). The oxidation reactivity of these samples was explored by a thermogravimetric analyzer (TGA). Different soot samples were collected in the tail of the tube. With the increase of temperature, the soot showed a smaller mean particle diameter, a longer fringe length, and a lower fringe tortuosity, as well as a higher degree of graphization. However, the variation of soot nanostructures resulting from different CO additions was not linear. Compared with 0%, 50%, and 100% CO additions at one fixed temperature, the soot collected from the 10% CO addition has the highest degree of graphization and crystallization. At three temperatures of 1173 K, 1223 K, and 1273 K, the mean values of fringe length distribution displayed a ranking of 10% CO >100% CO >50% CO while the mean particle diameters showed the same order. Furthermore, the oxidation reactivity of different soot samples decreased in the ranking of 50% CO addition>100% CO addition>10% CO addition, which was equal to the ranking of mean values of fringe tortuosity distribution. The result further confirmed the close relationship between soot nanostructure and oxidation reactivity.

关键词： 2     5-dimethylfuran pyrolysis     soot     CO2 addition     nanostructure     reactivity    

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Photochemical indicators of ozone sensitivity: application in the Pearl River Delta, China

Lyumeng Ye,Xuemei Wang,Shaofeng Fan,Weihua Chen,Ming Chang,Shengzhen Zhou,Zhiyong Wu,Qi Fan

《环境科学与工程前沿（英文）》 2016年 第10卷 第6期 doi: 10.1007/s11783-016-0887-1

摘要： The distribution of NO - and VOC-sensitive regimes in the PRD are identified. The effectiveness of six popular chemical indicators for discriminating O sensitivity regimes is evaluated. Threshold levels for HCHO/NO , H O /HNO , O /NO , O /NO , O /HNO were derived and verified. The indicators H O /HNO and H O /NO performed best and maintained relatively stable threshold levels. Surface O production has a highly nonlinear relationship with its precursors. The spatial and temporal heterogeneity of O -NO -VOC-sensitivity regimes complicates the control- decision making. In this paper, the indicator method was used to establish the relationship between O sensitivity and assessment indicators. Six popular ratios indicating ozone-precursor sensitivity, HCHO/NO , H O /HNO , O /NO , O /NO , O /HNO , and H O /NO , were evaluated based on the distribution of NO - and VOC-sensitive regimes. WRF-Chem was used to study a serious ozone episode in fall over the Pearl River Delta (PRD). It was found that the south-west of the PRD is characterized by a VOC-sensitive regime, while its north-east is NO -sensitive, with a sharp transition area between the two regimes. All indicators produced good representations of the elevated ozone hours in the episode on 6 November 2009, with H O /HNO being the best indicator. The threshold sensitivity levels for HCHO/NO , H O /HNO , O /NO , O /NO , O /HNO , and H O /NO were estimated to be 0.41, 0.55, 10.2, 14.0, 19.1, and 0.38, respectively. Threshold intervals for the indicators H O /HNO , O /NO , O /NO , O /HNO , and H O /NO were able to identify more than 95% of VOC- and NO -sensitive grids. The ozone episode on 16 November 16 2008 was used to independently verify the results, and it was found that only H O /HNO and H O /NO were able to differentiate the ozone sensitivity regime well. Hence, these two ratios are suggested as the most appropriate indicators for identifying fall ozone sensitivity in the PRD. Since the species used for indicators have seasonal variation, the utility of those indicators for other seasons should be investigated in the future work.

关键词： Ozone     Pearl River Delta (PRD)     Sensitivity regime     Photochemical indicator     Threshold levels    

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Atmospheric heterogeneous reaction of chlorobenzene on mineral -FeO particulates: a chamber experiment study

《环境科学与工程前沿（英文）》 2023年 第17卷 第11期 doi: 10.1007/s11783-023-1734-9

摘要：

● Photochemical conversion of chlorobenzene (CB) on α-Fe2O3 was evaluated.

关键词： Photochemical conversion     Chlorobenzene     α-Fe2O3     PCDD/Fs     Mineral particulate    

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Effect of pressure on gasification reactivity of three Chinese coals with different ranks

Chunyu LI, Jiantao ZHAO, Yitian FANG, Yang WANG

《化学科学与工程前沿（英文）》 2010年 第4卷 第4期   页码 385-393 doi: 10.1007/s11705-010-0501-1

摘要： The gasification reactivities of three kinds of different coal ranks (Huolinhe lignite, Shenmu bituminous coal, and Jincheng anthracite) with CO and H O was carried out on a self-made pressurized fixed-bed reactor at increased pressures (up to 1.0 MPa). The physicochemical characteristics of the chars at various levels of carbon conversion were studied via scanning electron microscopy (SEM), X-ray diffraction (XRD), and BET surface area. Results show that the char gasification reactivity increases with increasing partial pressure. The gasification reaction is controlled by pore diffusion, the rate decreases with increasing total system pressure, and under chemical kinetic control there is no pressure dependence. In general, gasification rates decrease for coals of progressively higher rank. The experimental results could be well described by the shrinking core model for three chars during steam and CO gasification. The values of reaction order with steam were 0.49, 0.46, 0.43, respectively. Meanwhile, the values of reaction order with CO were 0.31, 0.28, 0.26, respectively. With the coal rank increasing, the pressure order is higher, the activation energies increase slightly with steam, and the activation energy with CO increases noticeably. As the carbon conversion increases, the degree of graphitization is enhanced. The surface area of the gasified char increases rapidly with the progress of gasification and peaks at about 40% of char gasification.

关键词： coal     gasification     pressure     reaction order     shrinking core model    

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Effect of Fe loading quantity on reduction reactivity of nano zero-valent iron supported on chelating

Jialu SHI,Shengnan YI,Chao LONG,Aimin LI

《环境科学与工程前沿（英文）》 2015年 第9卷 第5期   页码 840-849 doi: 10.1007/s11783-015-0781-2

摘要： In this study, nanoscale zero-valent iron (NZVI) were immobilized within a chelating resin (DOW 3N). To investigate the effect of Fe loading on NZVI reactivity, three NZVI-resin composites with different Fe loading were obtained by preparing Fe(III) solution in 0, 30 and 70% (v/v) ethanol aqueous, respectively; the bromate was used as a model contaminant. TEM reveals that increasing the Fe loading resulted in much larger size and poor dispersion of nanoscale iron particles. The results indicated that the removal efficiency of bromate and the rate constant ( ) were decreased with increasing the Fe loading. For the NZVI-resin composite with lower Fe loading, the removal efficiency of bromate declined more significantly with the increase of DO concentrations. Under acidic conditions, decreasing the pH value had the most significant influence on NZVI-R3 with highest Fe loading for bromate removal; however, under alkaline conditions, the most significant influence of pH was on NZVI-R1 with lowest Fe loading. The effects of co-existing anions , and were also investigated. All of the co-existing anions showed the inhibition to bromate reduction.

关键词： nanoscale zero valent iron     loading quantity     reduction     chelating resin     bromated    

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Optimizing synthesis conditions of nanoscale zero-valent iron (nZVI) through aqueous reactivity assessment

Yanlai HAN,Michael D. Y. YANG,Weixian ZHANG,Weile YAN

《环境科学与工程前沿（英文）》 2015年 第9卷 第5期   页码 813-822 doi: 10.1007/s11783-015-0784-z

摘要： Nanoscale iron particles (nZVI) is one of the most important engineered nanomaterials applied to environmental pollution control and abatement. Although a multitude of synthesis approaches have been proposed, a facile method to screen the reactivity of candidate nZVI materials produced using different methods or under varying synthesis conditions has yet been established. In this study, four reaction parameters were adjusted in the preparation of borohydride-reduced nZVI. The reductive properties of the resultant nanoparticles were assayed independently using two model aqueous contaminants, Cu(II) and nitrate. The results confirm that the reductive reactivity of nZVI is most sensitive to the initial concentration of iron precursor, borohydride feed rate, and the loading ratio of borohydride to ferric ion during particle synthesis. Solution mixing speed, in contrast, carries a relative small weight on the reactivity of nZVI. The two probing reactions (i.e., Cu(II) and nitrate reduction) are able to generate consistent and quantitative inference about the mass-normalized surface activity of nZVI. However, the nitrate assay is valid in dilute aqueous solutions only (50 mg·L or lower) due to accelerated deactivation of iron surface at elevated nitrate concentrations. Additional insights including the structural and chemical makeup of nZVI can be garnered from Cu(II) reduction assessments. The reactivity assays investigated in this study can facilitate screening of candidate materials or optimization of nZVI production parameters, which complement some of the more sophisticated but less chemically specific material characterization methods used in the nZVI research.

关键词： iron nanoparticles     nanoscale iron particles (nZVI)     synthesis     characterization     Cu(II) reduction     nitrate reduction    

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Using hybrid models to predict blood pressure reactivity to unsupported back based on anthropometric

Gurmanik KAUR,Ajat Shatru ARORA,Vijender Kumar JAIN

《信息与电子工程前沿（英文）》 2015年 第16卷 第6期   页码 474-485 doi: 10.1631/FITEE.1400295

摘要： Accurate blood pressure (BP) measurement is essential in epidemiological studies, screening programmes, and research studies as well as in clinical practice for the early detection and prevention of high BP-related risks such as coronary heart disease, stroke, and kidney failure. Posture of the participant plays a vital role in accurate measurement of BP. Guidelines on measurement of BP contain recommendations on the position of the back of the participants by advising that they should sit with supported back to avoid spuriously high readings. In this work, principal component analysis (PCA) is fused with forward stepwise regression (SWR), artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS), and the least squares support vector machine (LS-SVM) model for the prediction of BP reactivity to an unsupported back in normotensive and hypertensive participants. PCA is used to remove multi-collinearity among anthropometric predictor variables and to select a subset of components, termed ‘principal components’ (PCs), from the original dataset. The selected PCs are fed into the proposed models for modeling and testing. The evaluation of the performance of the constructed models, using appropriate statistical indices, shows clearly that a PCA-based LS-SVM (PCA-LS-SVM) model is a promising approach for the prediction of BP reactivity in comparison to others. This assessment demonstrates the importance and advantages posed by hybrid models for the prediction of variables in biomedical research studies.

关键词： Blood pressure (BP)     Principal component analysis (PCA)     Forward stepwise regression     Artificial neural network (ANN)     Adaptive neuro-fuzzy inference system (ANFIS)     Least squares support vector machine (LS-SVM)    

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Effect of temperature on Lu’an bituminous char structure evolution in pyrolysis and combustion

Yandi ZHANG, Yinhe LIU, Xiaoli DUAN, Yao ZHOU, Xiaoqian LIU, Shijin XU

《能源前沿（英文）》 2021年 第15卷 第1期   页码 14-25 doi: 10.1007/s11708-020-0805-x

摘要： In the process of pyrolysis and combustion of coal particles, coal structure evolution will be affected by the ash behavior, which will further affect the char reactivity, especially in the ash melting temperature zone. Lu’an bituminous char and ash samples were prepared at the N and air atmospheres respectively across ash melting temperature. A scanning electron microscope (SEM) was used to observe the morphology of char and ash. The specific surface area (SSA) analyzer and thermogravimetric analyzer were respectively adopted to obtain the pore structure characteristics of the coal chars and combustion parameters. Besides, an X-ray diffractometer (XRD) was applied to investigate the graphitization degree of coal chars prepared at different pyrolysis temperatures. The SEM results indicated that the number density and physical dimension of ash spheres exuded from the char particles both gradually increased with the increasing temperature, thus the coalescence of ash spheres could be observed obviously above 1100°C. Some flocculent materials appeared on the surface of the char particles at 1300°C, and it could be speculated that -Si N was generated in the pyrolysis process under N . The SSA of the chars decreased with the increasing pyrolysis temperature. Inside the char particles, the micropore area and its proportion in the SSA also declined as the pyrolysis temperature increased. Furthermore, the constantly increasing pyrolysis temperature also caused the reactivity of char decrease, which is consistent with the results obtained by XRD. The higher combustion temperature resulted in the lower porosity and more fragments of the ash.

关键词： bituminous char     pyrolysis     ash     structure evolution     reactivity    

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Reactivity of Pyrogenic Carbonaceous Matter (PCM) in mediating environmental reactions: Current knowledge

Wenqing Xu, Mark L. Segall, Zhao Li

《环境科学与工程前沿（英文）》 2020年 第14卷 第5期 doi: 10.1007/s11783-020-1265-6

摘要： Abstract • Pyrogenic Carbonaceous Matter (PCM) promote both chemical and microbial synergies. • Discussion of PCM-enhanced abiotic transformation pathways of organic pollutants. • Conjugated microporous polymers (CMPs) can mimic the performance of PCM. • CMPs offer a platform that allows for systematic variation of individual properties. Pyrogenic Carbonaceous matter (PCM; e.g., black carbon, biochar, and activated carbon) are solid residues from incomplete combustion of fossil fuel or biomass. They are traditionally viewed as inert adsorbents for sequestering contaminants from the aqueous phase or providing surfaces for microbes to grow. In this account, we reviewed the recently discovered reactivity of PCM in promoting both chemical and microbial synergies that are important in pollutant transformation, biogeochemical processes of redox-active elements, and climate change mitigation with respect to the interaction between biochar and nitrous oxide (N2O). Moreover, we focused on our group’s work in the PCM-enhanced abiotic transformation of nitrogenous and halogenated pollutants and conducted in-depth analysis of the reaction pathways. To understand what properties of PCM confer its reactivity, our group pioneered the use of PCM-like polymers, namely conjugated microporous polymers (CMPs), to mimic the performance of PCM. This approach allows for the controlled incorporation of specific surface properties (e.g., quinones) into the polymer network during the polymer synthesis. As a result, the relationship between specific characteristics of PCM and its reactivity in facilitating the decay of a model pollutant was systematically studied in our group’s work. The findings summarized in this account help us to better understand an overlooked environmental process where PCM synergistically interacts with various environmental reagents such as hydrogen sulfide and water. Moreover, the knowledge gained in these studies could inform the design of a new generation of reactive carbonaceous materials with tailored properties that are highly efficient in contaminant removal.

关键词： pyrogenic carbonaceous matter     Conjugated microporous polymer     remediation     Biochar     Hydrolysis     Pollutant degradation    

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Decomposition of aqueous chlorinated contaminants by UV irradiation with H

Eunsung KAN,Chang-Il KOH,Kyunghyuk LEE,Joonwun KANG

《环境科学与工程前沿（英文）》 2015年 第9卷 第3期   页码 429-435 doi: 10.1007/s11783-014-0677-6

摘要： In the present study, the decomposition rates of carbon tetrachloride (CCl ) and 2,4-dichlorophenol (2,4-DCP) in water by the ultraviolet (UV) light irradiation alone and H O /UV were experimentally investigated. The detailed experimental studies have been conducted for examining treatment capacities of the two different ultraviolet light sources (low and medium pressure Hg arc) in H O /UV processes. The low or medium UV lamp alone resulted in a 60%–90% decomposition of 2,4-DCP while a slight addition of H O resulted in a drastic enhancement of the 2,4-DCP decomposition rate. The decomposition rate of 2,4-DCP with the medium pressure UV lamp alone was about 3–6 times greater than the low pressure UV lamp alone. In the direct photolysis of aqueous CCl , the medium pressure UV lamp had advantage over the low pressure UV lamp because the molar extinction coefficient of CCl at shorter wavelength (210–220 nm) is about 20 to 50 times higher than that at 254 nm. However, adding H O to the medium pressure UV lamp system rendered a negative oxidation rate because H O acted as a UV absorber being competitive with CCl due to negligible reaction between CCl and OH radicals. The results from the present study indicated significant influence of the photochemical properties of the target contaminants on the photochemical treatment characteristics for designing cost-effective UV-based degradation of toxic contaminants.

关键词： H2O2/ultraviolet (UV) light     advanced oxidation     UV light irradiation     chlorinated contaminants     photochemical treatment characteristics    

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标题 作者 时间 类型 操作

Behavior of aqueous stable colloidal nano-C

Jing HUO,Ye YU,Ling GE,Bo ZHANG,Yiliang HE

期刊论文

Parameter for judging reactivity of coal and coke

HE Hongzhou, LUO Zhongyang, CEN Kefa

期刊论文

Surface modification of biomaterials by photochemical immobilization and photograft polymerization to

Yakai FENG, Haiyang ZHAO, Li ZHANG, Jintang GUO,

期刊论文

Identification of sources, characteristics and photochemical transformations of dissolved organic matter

期刊论文

Effects of different types of biochar on the properties and reactivity of nano zero-valent iron in soil

期刊论文

Nanostructure and reactivity of soot from biofuel 2,5-dimethylfuran pyrolysis with CO

Lijie ZHANG, Kaixuan YANG, Rui ZHAO, Mingfei CHEN, Yaoyao YING, Dong LIU

期刊论文

Photochemical indicators of ozone sensitivity: application in the Pearl River Delta, China

Lyumeng Ye,Xuemei Wang,Shaofeng Fan,Weihua Chen,Ming Chang,Shengzhen Zhou,Zhiyong Wu,Qi Fan

期刊论文

Atmospheric heterogeneous reaction of chlorobenzene on mineral -FeO particulates: a chamber experiment study

期刊论文

Effect of pressure on gasification reactivity of three Chinese coals with different ranks

Chunyu LI, Jiantao ZHAO, Yitian FANG, Yang WANG

期刊论文

Effect of Fe loading quantity on reduction reactivity of nano zero-valent iron supported on chelating

Jialu SHI,Shengnan YI,Chao LONG,Aimin LI

期刊论文

Optimizing synthesis conditions of nanoscale zero-valent iron (nZVI) through aqueous reactivity assessment

Yanlai HAN,Michael D. Y. YANG,Weixian ZHANG,Weile YAN

期刊论文

Using hybrid models to predict blood pressure reactivity to unsupported back based on anthropometric

Gurmanik KAUR,Ajat Shatru ARORA,Vijender Kumar JAIN

期刊论文

Effect of temperature on Lu’an bituminous char structure evolution in pyrolysis and combustion

Yandi ZHANG, Yinhe LIU, Xiaoli DUAN, Yao ZHOU, Xiaoqian LIU, Shijin XU

期刊论文

Reactivity of Pyrogenic Carbonaceous Matter (PCM) in mediating environmental reactions: Current knowledge

Wenqing Xu, Mark L. Segall, Zhao Li

期刊论文

Decomposition of aqueous chlorinated contaminants by UV irradiation with H

Eunsung KAN,Chang-Il KOH,Kyunghyuk LEE,Joonwun KANG

期刊论文