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Recovery of NH

Yang ZHANG,Zifu LI,Ibrahim B MAHMOOD

《环境科学与工程前沿(英文)》 2014年 第8卷 第6期   页码 825-834 doi: 10.1007/s11783-014-0682-9

摘要: ion, a main pollutant in aquatic systems, not only causes eutrophication in rivers and lakes but also contributes to fish toxicity. In this study, an eco-friendly biosorbent was prepared from the pyrolysis of corn cob, a low-cost agricultural residue. The biochars produced by pyrolysis of corn cob at 400°C and 600°C were characterized and investigated as adsorbents for from an aqueous solution. The biochars were characterized through elemental analysis, Brunauer–Emmett–Teller–N surface area analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy. Batch experiments were conducted to investigate the adsorption process of the corn cob biochars. The Freundlich isotherm model fitted the adsorption process better than the Langmuir and Dubinin–Radushkevich isotherm models. Moreover, the adsorption process was well described by a pseudo-second-order kinetic model. Results of thermodynamic analysis suggested that adsorption was a nonspontaneous exothermic process. Biochars produced at 400°C had higher adsorption capacity than those produced at 600°C because of the presence of polar functional groups with higher acidity. The exhausted biochar can be potentially used as soil conditioner, which can provide 6.37 kg (N fertilizer per ton of biochar).

关键词: corn cob     biochar     isotherm model     kinetic model        

Preparation of adsorptive nanoporous membrane using powder activated carbon: Isotherm and thermodynamic

Majid Peyravi

《化学科学与工程前沿(英文)》 2020年 第14卷 第4期   页码 673-687 doi: 10.1007/s11705-019-1800-9

摘要: Adsorptive polyethesulfone (PES) membranes were prepared by intercalation of powder activated carbon (PAC) with and without functionalization. Accordingly, PAC was aminated with 1,5-diamino-2-methylpentane, and the physicochemical properties of the functionalized PAC were analyzed. Intercalation of PAC within the PES scaffold changed the porosity and mean pore size of the aminated membrane (AC-NH ) from 52.6% to 92.5% and from 22.6 nm to 3.5 nm, respectively. The effect of temperature on the performance of the modified membranes was monitored by the flux and chemical oxygen demand (COD) removal of leachate. At ambient temperature, the COD removal of the neat, AC-containing, and AC-NH membranes was 47%, 52%, and 58.5%, respectively. A similar increment was obtained for the membrane flux, which was due to the synergistic effect of the high porosity and large number of hydrophilic functional groups. The experimental leachate adsorption data were analyzed by Langmuir, Freundlich, and Dubinin- Radushkevich isotherm models. For all membranes, the significant thermodynamic parameters ( , , and ) were calculated and compared. The isosteric heat of adsorption was lower than 80 kJ∙mol , indicating that the interaction between the membranes and the leachate is mainly physical, involving weak van der Waals forces.

关键词: amine functionality     nanoporous membrane     adsorption isotherm     thermodynamic parameters     landfill leachate    

Removal of copper by modified chitosan adsorptive membrane

Xiaoshuai LIU, Zihong CHENG, Wei MA

《化学科学与工程前沿(英文)》 2009年 第3卷 第1期   页码 102-106 doi: 10.1007/s11705-009-0123-7

摘要: In this study, a novel adsorptive membrane was prepared from chitosan as the functional polymer and some additive blend solutions by solution casting method. The modified chitosan membrane was characterized by FTIR and its Water Swelling Ratio (WSR). The adsorption of copper ions on the adsorptive membrane was investigated in batch experiments. The results obtained from the experiments indicated that the membrane had a good adsorption capacity for copper ions, the optimal ionic strength and pH were 0.1 and 5-6, respectively. Compared with the Langmuir isotherm model, the experimental data were found to be following the Freundlich model.

关键词: chitosan     adsorptive membrane     copper removal     environmental engineering     heavy metal     isotherm model    

Contributions of adsorption, bioreduction and desorption to uranium immobilization by extracellular polymeric substances

《环境科学与工程前沿(英文)》 2023年 第17卷 第9期 doi: 10.1007/s11783-023-1707-z

摘要:

● EPS immobilizes U(VI) via adsorption, bioreduction and desorption.

关键词: Adsorption     Bioreduction     Desorption     Kinetics     Isotherm     Uranium    

Immobilized

Pei MA, Dan ZHANG

《环境科学与工程前沿(英文)》 2012年 第6卷 第4期   页码 498-508 doi: 10.1007/s11783-012-0429-4

摘要: To investigate the potential use of ( ) residue for Cd adsorption, poly alcohol Na alginate (PVA) was applied to immobilize it. The parameters including contact time, pH, adsorbent dosages, and coexisting metal ions were studied. The suitable pH for immobilized was 4–7 wider than that for raw (pH 6–7). In the presence of Pb concentration varying from 0 to 30 mg·L , the Cd adsorption ratios declined by 6.71% and 47.45% for immobilized and raw , respectively. While, with the coexisting ion Cu concentration varied from 0 to 30 mg·L , the Cd adsorption ratios declined by 12.97% and 50.56% for immobilized and raw , respectively. The Cd adsorption isotherms in single–metal and dual-metal solutions were analyzed by using Langmuir, Freundlich, and Dubinin–Radushkevich models. The Cd adsorption capacities ( ) in single-metal solution were 6.448 mg·L and 2.832 mg·L for immobilized and raw , respectively. The of immobilized were 1.850 mg Cd·g in Cd + Pb solution and 3.961 mg Cd·g in Cd + Cu solution, respectively. The Cd adsorption processes subjected to both adsorbents follow pseudo-second-order model. Mechanism study showed the functional group of was –OH, –NH, –CO, and PVA played an important role in metal adsorbing. Mining wastewater treatment test showed that PVA–SA-immobilized was effective in mixed pollutant treatment even for wastewater containing metal ions in very low concentration.

关键词: immobilization     Lentinus edodes residue     competitive adsorption     isotherm    

The prediction of adsorption isotherms of ester vapors on hypercrosslinked polymeric adsorbent

Liuyan WU,Lijuan JIA,Xiaohan LIU,Chao LONG

《环境科学与工程前沿(英文)》 2016年 第10卷 第3期   页码 482-490 doi: 10.1007/s11783-015-0826-6

摘要: Adsorption isotherms of methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate and ethyl propionate on hypercrosslinked polymeric resin (ND-100) were measured at 303K, 318K and 333K,respectively, and well fitted by Dubinin–Astakhov (DA) equation. The plots of the adsorbed volume ( ) versus the adsorption potential ( ) at three different temperatures all fell basically onto one single curve for every ester. A predicted model based on DA equation was obtained on the basis of adsorption equilibrium data of methyl acetate, ethyl acetate and ethyl propionate at 318K. The model equation successfully predicted the adsorption isotherms of methyl acetate, ethyl acetate and ethyl propionate on ND-100 at 303K, and 333K, and also gave accurate predictive results for adsorption isotherms of the other two ester compounds (propyl acetate and isopropyl acetate) on ND-100 at 303K, 318K and 333K. The results proved the effectiveness of DA model for predicting the adsorption isotherms of ester compounds onto ND-100. In addition, the relationship between physico-chemical properties of adsorbates and their adsorption properties was also investigated. The results showed that molecular weight, molar volume and molar polarizability had good linear correlations with the parameter (which represents adsorption characteristic energy) of DA equation.

关键词: hypercrosslinked polymeric adsorbent     adsorption isotherm     ester     prediction    

Facile synthesis of α-MnO

Weixin ZHANG, Wenran ZHAO, Zaoyuan ZHOU, Zeheng YANG

《化学科学与工程前沿(英文)》 2014年 第8卷 第1期   页码 64-72 doi: 10.1007/s11705-014-1402-5

摘要: In this paper, α-MnO micronests composed of nanowires were fabricated via a hydrothermal reaction of MnSO ·H O and K S O solutions. The α-MnO micronests were demonstrated to have a higher adsorption capacity than γ-MnO microspheres due to their large specific surface area. The amount of Congo red adsorbed per unit weight of α-MnO micronests increased significantly from 114 to 282 mg·g with concentration of Congo red solution increasing from 50 to 200 mg·L , but it had a little change with temperature. Kinetics, isotherms and thermodynamics for the adsorption of Congo red on α-MnO micronests were examined. The adsorption process followed the pseudo-second-order kinetics with good correlation. The experimental data were analyzed by Langmuir and Freundlich models, and equilibrium data fitted the Langmuir isotherm very well with maximum monolayer adsorption capacity of 625 mg·g at 22 °C. The adsorption was spontaneous and endothermic according to thermodynamic studies. The experimental results indicate that α-MnO micronests possess a high adsorption capacity and could be employed as a replacement of traditional sorbents.

关键词: MnO2     Congo red     adsorption     kinetics     isotherm     thermodynamics    

Preparation and characterization of

Chunhua XU, Dandan CHENG, Baoyu GAO, Zhilei YIN, Qinyan YUE, Xian ZHAO

《环境科学与工程前沿(英文)》 2012年 第6卷 第4期   页码 455-462 doi: 10.1007/s11783-010-0275-1

摘要: Batch adsorption experiments were conducted to explore the adsorption of Cr(VI) in aqueous solutions by -FeOOH-coated sand. We investigated the key factors which affected the adsorption process such as adsorbent dosage, initial pH, initial Cr(VI) ion concentration, contact time and temperature. The uptake of Cr(VI) was very rapid and 44.3%, 51.6%, 58.9% of the adsorption happened during the first 180 minutes at 293K, 303K and 313K, respectively. The pseudo-second-order rate equation successfully described the adsorption kinetics. To study the adsorption isotherm, two equilibrium models, the Langmuir and Freundlich isotherms, were adopted. At 293K, 303K and 313K, the adsorption capacities obtained from the Langmuir isotherm were 0.060, 0.070 and 0.076 mg Cr(VI) per gram of the adsorbent, respectively. Thermodynamic parameters such as the change of energy, enthalpy and entropy were calculated using the equilibrium constants. The negative value of and the positive value of showed that the adsorption of Cr(VI) in aqueous solutions by -FeOOH-coated sand was spontaneous, endothermic and occurred by physisorption.

关键词: β-FeOOH-coated sand     Cr(VI)     adsorption     isotherm     kinetics    

Selective removal of phenol by spherical particles of

Qingchuan CHEN, Yicun WEN, Yu CANG, Li LI, Xuhong GUO, Rui ZHANG

《化学科学与工程前沿(英文)》 2013年 第7卷 第2期   页码 162-169 doi: 10.1007/s11705-013-1318-5

摘要: Spherical particles of -, - and -cyclodextrin (CD) polymers to efficiently remove phenol from waste water were prepared by reverse suspension polymerization with epichlorohydrin as crosslinker in liquid paraffin. By controlling the amounts of crosslinker and water, well-defined spherical polymer particles with controllable size were obtained. Due to the selective inclusion associations between CD groups and phenol, these CD spherical polymer particles were demonstrated to be ideal candidates for removal of phenol. Among them -CD polymer particles showed the best performance. The kinetics and isothermal equilibrium models were used to fit the experimental data of phenol removal from aqueous solution using these CD polymer particles. It was found that the kinetics followed the Ho and Mckay equation, suggesting that the adsorption process of phenol was controlled by diffusion and the host-guest interaction between CD and phenol. Equilibrium isothermal data can be well fitted by the Freundlich equation. The negative free energy change indicated the spontaneous nature of adsorption of phenol by -, - and -CD spherical polymer particles, while the lowest free energy for -CD polymer reflected its best adsorption ability, compared to - and -CD polymer particles.

关键词: cyclodextrin polymer particles     phenol     kinetic models     adsorption isotherm equilibrium models    

Performance and mechanism for cadmium and lead adsorption from water and soil by corn straw biochar

Tong Chi,Jiane Zuo,Fenglin Liu

《环境科学与工程前沿(英文)》 2017年 第11卷 第2期 doi: 10.1007/s11783-017-0921-y

摘要: Corn straw biochar prepared under 400 °C was the best Cd and Pb adsorption capacity Maximum adsorption capacity of Cd and Pb were 43.48 and 22.73 mg·g , respectively The dominant mechanism of Cd and Pb adsorption was precipitation Biochar could reduce the bioavailability of heavy metals when mixed with soil Cadmium (Cd) and lead (Pb) in water and soil could be adsorbed by biochar produced from corn straw. Biochar pyrolyzed under 400°C for 2 h could reach the ideal removal efficiencies (99.24% and 98.62% for Cd and Pb, respectively) from water with the biochar dosage of 20 g·L and initial concentration of 20 mg·L . The pH value of 4–7 was the optimal range for adsorption reaction. The adsorption mechanism was discussed on the basis of a range of characterizations, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and Raman analysis; it was concluded as surface complexation with active sorption sites (-OH, -COO-), coordination with π electrons (C= C, C= O) and precipitation with inorganic anions (OH , CO , SO ) for both Cd and Pb. The sorption isotherms fit Langmuir model rather than Freundlich model, and the saturated sorption capacities for Cd and Pb were 38.91 mg·g and 28.99 mg·g , respectively. When mixed with soil, biochar could effectively increase alkalinity and reduce bioavailability of heavy metals. Thus, biochar derived from corn straw would be a green material for both removal of heavy metals and amelioration of soil.

关键词: Corn straw     Biochar     Heavy metals     Sorption isotherm     Bioavailability    

Fabrication, characterization and evaluation of mesoporous activated carbons from agricultural waste: Jerusalem artichoke stalk as an example

Lei YU,Chen TU,Yongming LUO

《环境科学与工程前沿(英文)》 2015年 第9卷 第2期   页码 206-215 doi: 10.1007/s11783-014-0631-7

摘要: This work explores the feasibility of Jerusalem artichoke stem (JAS), an agricultural waste, as an alternative precursor for fabrication of mesoporous activated carbon (MAC) via conventional ZnCl activation. The as-prepared JAS-MACs were characterized by thermogravimetric, nitrogen gas adsorption isotherm and high resolution scanning electron microscopy analysis. The interacting effects of chemical dosage, activation temperature and time on the mesoporosity, mesopore volume and carbon yield were investigated, and further optimized by response surface methodology (RSM). The Brunauer-Emmett-Teller surface area, mesoporosity and mesopore volume of the JAS-MAC prepared under optimum condition were identified to be 1631 m ·g , 90.16% and 1.11 cm ·g , respectively. Compared with commercial activated carbons, this carbon exhibited a comparable monolayer adsorption capacity of 374.5 mg·g for Methylene Blue dye. The findings suggest that RSM could be an effective approach for optimizing the pore structure of fabricated activated carbons.

关键词: mesoporous activated carbon     response surface methodology     adsorption isotherm     agricultural wastes    

Effect of textural property of coconut shell-based activated carbon on desorption activation energy of benzothiophene

YU Moxin, LI Zhong, XI Hongxia, XIA Qibin, WANG Shuwen

《化学科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 269-275 doi: 10.1007/s11705-008-0056-6

摘要: In this work, the effect of the textural property of activated carbons on desorption activation energy and adsorption capacity for benzothiophene (BT) was investigated. BET surface areas and the textural parameters of three kinds of the activated carbons, namely SY-6, SY-13 and SY-19, were measured with an ASAP 2010 instrument. The desorption activation energies of BT on the activated carbons were determined by temperature-programmed desorption (TPD). Static adsorption experiments were carried out to determine the isotherms of BT on the activated carbons. The influence of the textural property of the activated carbons on desorption activation energy and the adsorption capacity for BT was discussed. Results showed that the BET surface areas of the activated carbons, SY-6, SY-13 and SY-19 were 1106, 1070 and 689 mg, respectively, and their average pore diameters were 1.96, 2.58 and 2.16 nm, respectively. The TPD results indicated that the desorption activation energy of BT on the activated carbons, SY-6, SY-19 and SY-13 were 58.84, 53.02 and 42.57 KJ/mol, respectively. The isotherms showed that the amount of BT adsorbed on the activated carbons followed the order of SY-6 > SY-19 > SY-13. The smaller the average pore diameter of the activated carbon, the stronger its adsorption for BT and the higher the activation energy required for BT desorption on its surface. The Freundlich adsorption isotherm model can be properly used to formulate the adsorption behavior of BT on the activated carbons.

关键词: diameter     adsorption isotherm     ASAP     SY-19 >     activated    

Adsorption of 1,3-propanediol from synthetic mixture using polymeric resin as adsorbents

W. LUERRUK, A. SHOTIPRUK, V. TANTAYAKOM, P. PRASITCHOKE, C. MUANGNAPOH

《化学科学与工程前沿(英文)》 2009年 第3卷 第1期   页码 52-57 doi: 10.1007/s11705-009-0087-7

摘要: The aim of this work was to separate 1,3-PDO from a synthetic mixture using polymeric resins, Amberlite XAD-7 and XAD-16 resins. The equilibrium adsorption of 1,3-PDO onto two polymeric resins were investigated in binary and tertiary systems. Experimental results of binary component adsorption equilibrium indicated that the adsorption capacity ( ) of 1,3-PDO at 160 g/L onto XAD-7 and XAD-16 was 835.96 and 584.61 mg 1,3-PDO/g dry resin, respectively. The adsorption isotherms were closely predicted by the Langmuir-Freundlich model among the two isotherm model tested. The value of n of 1,3-PDO adsorbed on XAD-7 are much higher than those on XAD-16. This result suggested that XAD-7 resin has a higher affinity for the 1,3-PDO adsorption than XAD-16 resin. Moreover, the value of adsorption capacity of 1,3-PDO in the binary and tertiary component were compared at the same conditions. In the tertiary system, although the selectivity of 1,3-PDO from XAD-7 was approximately six times higher than XAD-16, the adsorption capacity of 1,3-PDO at 160 g/L onto XAD-16 was higher than XAD-7. Interestingly, the reusability of XAD-7 and XAD-16 resins in the three cycle times shows a slight loss of adsorption capacity. Furthermore, the investigation about desorption by an ethanol/water mixture at 50% ( / ) indicated that the desorption yield of 1,3-PDO from XAD-7 was lower than XAD-16 resin for both the binary and tertiary component. This was due to the more favorable adsorption characteristics of XAD-7 resin than XAD-16 resin.

关键词: adsorption     1     3-propanediol     glycerol     polymeric resin     adsorption isotherm    

香蕉假茎作为吸附剂用于水溶液中铅离子去除的条件优化、动力学与吸附平衡研究 Article

Shridhar S. Bagali, Bychapur S. Gowrishankar, Aashis S. Roy

《工程(英文)》 2017年 第3卷 第3期   页码 409-415 doi: 10.1016/J.ENG.2017.03.024

摘要:

香蕉假茎粉末等天然吸附剂对于去除废水中的重金属元素具有非常重要的作用。现有的去除重金属元素的常规方法难以满足水资源循环和化学工业的需求。本文论证了利用天然物质处理废水的可能性。利用环境扫描电子显微镜(ESEM) 和傅里叶变换红外(FTIR) 光谱学分析方法,研究了香蕉假茎粉末吸附铅离子前后的变化。实验采用批处理方法研究了水溶液中铅离子去除的效果。通过改变初始pH 值、吸附剂用量、初始铅离子浓度、吸附时间等参数,研究了吸附动力学的影响。结果表明,在水溶液pH 值为5.5 时,香蕉假茎粉末达到零电荷点。采用吸附等温线和动力学模型分析实验数据,采用朗缪尔吸附等温式拟合铅离子在香蕉假茎粉末表面的吸附作用。实验表明,香蕉假茎粉末对铅离子的吸附量为34.21 mg·g−1,与拟二级动力学模型相匹配。此外,采用响应面分析法确定了铅离子吸附的最佳条件,铅离子的去除率高达89%。

关键词: 香蕉假茎         等温线     吸附     响应面分析法    

Standard model of knowledge representation

Wensheng YIN

《机械工程前沿(英文)》 2016年 第11卷 第3期   页码 275-288 doi: 10.1007/s11465-016-0372-3

摘要:

Knowledge representation is the core of artificial intelligence research. Knowledge representation methods include predicate logic, semantic network, computer programming language, database, mathematical model, graphics language, natural language, etc. To establish the intrinsic link between various knowledge representation methods, a unified knowledge representation model is necessary. According to ontology, system theory, and control theory, a standard model of knowledge representation that reflects the change of the objective world is proposed. The model is composed of input, processing, and output. This knowledge representation method is not a contradiction to the traditional knowledge representation method. It can express knowledge in terms of multivariate and multidimensional. It can also express process knowledge, and at the same time, it has a strong ability to solve problems. In addition, the standard model of knowledge representation provides a way to solve problems of non-precision and inconsistent knowledge.

关键词: knowledge representation     standard model     ontology     system theory     control theory     multidimensional representation    

标题 作者 时间 类型 操作

Recovery of NH

Yang ZHANG,Zifu LI,Ibrahim B MAHMOOD

期刊论文

Preparation of adsorptive nanoporous membrane using powder activated carbon: Isotherm and thermodynamic

Majid Peyravi

期刊论文

Removal of copper by modified chitosan adsorptive membrane

Xiaoshuai LIU, Zihong CHENG, Wei MA

期刊论文

Contributions of adsorption, bioreduction and desorption to uranium immobilization by extracellular polymeric substances

期刊论文

Immobilized

Pei MA, Dan ZHANG

期刊论文

The prediction of adsorption isotherms of ester vapors on hypercrosslinked polymeric adsorbent

Liuyan WU,Lijuan JIA,Xiaohan LIU,Chao LONG

期刊论文

Facile synthesis of α-MnO

Weixin ZHANG, Wenran ZHAO, Zaoyuan ZHOU, Zeheng YANG

期刊论文

Preparation and characterization of

Chunhua XU, Dandan CHENG, Baoyu GAO, Zhilei YIN, Qinyan YUE, Xian ZHAO

期刊论文

Selective removal of phenol by spherical particles of

Qingchuan CHEN, Yicun WEN, Yu CANG, Li LI, Xuhong GUO, Rui ZHANG

期刊论文

Performance and mechanism for cadmium and lead adsorption from water and soil by corn straw biochar

Tong Chi,Jiane Zuo,Fenglin Liu

期刊论文

Fabrication, characterization and evaluation of mesoporous activated carbons from agricultural waste: Jerusalem artichoke stalk as an example

Lei YU,Chen TU,Yongming LUO

期刊论文

Effect of textural property of coconut shell-based activated carbon on desorption activation energy of benzothiophene

YU Moxin, LI Zhong, XI Hongxia, XIA Qibin, WANG Shuwen

期刊论文

Adsorption of 1,3-propanediol from synthetic mixture using polymeric resin as adsorbents

W. LUERRUK, A. SHOTIPRUK, V. TANTAYAKOM, P. PRASITCHOKE, C. MUANGNAPOH

期刊论文

香蕉假茎作为吸附剂用于水溶液中铅离子去除的条件优化、动力学与吸附平衡研究

Shridhar S. Bagali, Bychapur S. Gowrishankar, Aashis S. Roy

期刊论文

Standard model of knowledge representation

Wensheng YIN

期刊论文