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The biosorption of Cr(VI) ions by dried biomass obtained from a chromium-resistant bacterium

Paul Fabrice NGUEMA,Zejiao LUO,Jingjing LIAN

《化学科学与工程前沿（英文）》 2014年 第8卷 第4期   页码 454-464 doi: 10.1007/s11705-014-1456-4

摘要： The biosorption potential of many different kinds of biomaterials has been widely studied. However, there is little data on the biosorption mechanism of Cr(VI) by dried biomass. So the bio-removal of Cr(VI) ions from aqueous solutions was investigated using dried biomass from a chromium-resistant bacterium. The bacterium was isolated from dewatered sludge samples that were obtained from a sewage treatment plant. Equilibrium and kinetic experiments were performed at different metal concentrations, pH values, and biosorbents dosages. The biomass was characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The functional groups in the biomass which may play a role in the biosorption process were identified by Fourier transform infrared spectroscopy. The biosorption process was found to be highly pH dependent and the optimum pH for the adsorption of Cr(VI) was 2.0±0.3 at 30±2 °C. The experimental data fit well with Langmuir and Freundlich models as well as a pseudo-second order kinetic model. The mechanism for the biosorption was also studied by fitting the kinetic data with an intra-particle diffusion model and a Boyd plot. External mass transfer was found to be the rate-determining step for the adsorption process. Biosorption could be an alternative mechanism besides bio-oxidation and bio-reduction for the bioremediation of heavy metals.

关键词： Cr(VI)     biomass     Bacillus cereus Pf-1     biosorption capacity     biosorbents    

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Biosorption of Cu(II) to extracellular polymeric substances (EPS) from

Xiangliang PAN, Jing LIU, Wenjuan SONG, Daoyong ZHANG

《环境科学与工程前沿（英文）》 2012年 第6卷 第4期   页码 493-497 doi: 10.1007/s11783-012-0416-9

摘要： Biosorption of extracellular polymeric substances (EPS) from sp. (cyanobacterium) with Cu(II) was investigated using fluorescence spectroscopy. Three fluorescence peaks were found in the excitation-emission matrix (EEM) fluorescence spectra of EPS. Fluorescence of peak A (Ex/Em= 275/452 nm) and peak C (Ex/Em= 350/452 nm) were originated from humic-like substances and fluorescence of peak B (Ex/Em= 275/338 nm) was attributed to protein-like substances. Fluorescence of peaks A, B, and C could be quenched by Cu(II). The effective quenching constants (lg K ) were 2.8–5.84 for peak A, 6.4–9.24 for peak B, and 3.48–6.68 for peak C, respectively. The values of lg K showed a decreasing trend with increasing temperature, indicating that the quenching processes were static in nature. The binding constants (lg K ) followed the order of peak A>peak B>peak C, implying that the humic-like substances in EPS have greater Cu(II) binding capacity than the protein-like substances. The binding site number, , in EPS-Cu(II) complexes for peaks A, B, and C was less than 1. This suggests the negative cooperativity between multiple binding sites and the presence of more than one Cu binding site.

关键词： biosorption     conditional binding constant     extracellular polymeric substances (EPS)     fluorescence quenching    

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Biosorption of mercury and lead by aqueous

Pratibha SANJENBAM, Kumar SAURAV, Krishnan KANNABIRAN

《化学科学与工程前沿（英文）》 2012年 第6卷 第2期   页码 198-202 doi: 10.1007/s11705-012-1285-2

摘要： Toxic heavy metals are increasingly accumulating in the environment worldwide and are considered to be life threatening contaminants. The biosorption of mercury and lead by marine actinomycetes isolated from marine sediment collected from the Bay of Bengal coast of Puducherry, India, was evaluated. The maximum tolerance concentration (MTC) of sp. was determined by a well diffusion method and a broth dilution method. The effects of the initial metal ion concentration, the pH and the biomass dosage on the biosorption of mercury and lead ions were investigated. The MTC of the isolate to metals was 200 mg·L for mercury and 1800 mg·L for lead. At neutral pH, the isolate had a maximum biosorption of metal ions of 200 mg·L and 150 mg·L for mercury and lead respectively. Fourier transform infrared (FTIR) absorption spectra showed the chemical interactions between the functional groups in the biomass such as hydroxyl (-OH), amine (-NH ), carboxyl (-COOH) and the metal ions. The isolate was further characterized by molecular taxonomy and identified as a member of the genus Based on the phenotypic and phylogenetic analysis, the strain was classified as a new species of the genus and designated as VITSVK9 sp. (HM137310). A blast search of the 16S rDNA sequence of the strain showed the most similarity (95%) with sp. A515 Ydz-FQ (EU384279). Based on the results, it can be concluded that this marine could be used as a biosorbent for the removal of heavy metal ions from aqueous environments.

关键词： mercury     lead     biosorption     maximum tolerance concentration     Streptomyces VITSVK9 sp.    

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Biosorption and biotransformation of crystal violet by

Tao PAN, Suizhou REN, Jun GUO, Meiying XU, Guoping SUN

《环境科学与工程前沿（英文）》 2013年 第7卷 第2期   页码 185-190 doi: 10.1007/s11783-012-0435-6

摘要： DN322p, an offspring of DN322, has the capacity to adsorb and decolorize triphenylmethane dyes in wastewater simultaneously. As a common triphenylmethane dye, crystal violet (CV) was chosen to test the decolorization characteristics of DN322p. Within 0.5 h, the strain DN322p adsorbed a large amount of CV, producing a deep-colored cell pellet and colorless supernatant. The colors of the cell pellet and supernatant lightened over time. The supernatant and dichloromethane extract of the cell pellet both showed conspicuous CV and leuco CV (LCV) characteristic absorbance peaks at 590 nm and 260 nm, respectively, in the UV-vis spectral analysis. This finding indicated that the DN322p cells can adsorb the two dyes. A 99% (w/w) decolorization rate was achieved within 2.5 h with shaking at 30°C for 50 mg CV·L . High Performance Liquid Chromatography (HPLC) analysis of the dichloromethane extract of the supernatant and cell pellet confirmed that CV was mainly converted into its leuco form. Dead cells had a similar adsorption capacity with living cells. About 90% of CV in the dye solution (50 mg·L ) was removed by autoclaved cells with an optical delnsity at 600 nm (OD ) above 1.0.

关键词： crystal violet     decolorization     biosorption     biotransformation     Aeromonas hydrophila DN322p    

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Biosorption of Cd

Fengyu ZAN, Shouliang HUO, Beidou XI, Xiulan ZHAO

《环境科学与工程前沿（英文）》 2012年 第6卷 第1期   页码 51-58 doi: 10.1007/s11783-011-0206-9

摘要： The biosorption of Cd and Cu onto the immobilized ( ) was investigated in this study. Adsorption kinetics, isotherms and the effect of pH were studied. The results indicated that the biosorption of Cd and Cu on the immobilized was fast at initial stage and then became slow. The maximum biosorption of heavy metal ions on immobilized were observed at pH 4 for Cd and Cu . by the pseudo-second-order model described the sorption kinetic data well according to the high correlation coefficient ( ) obtained. The biosorption isotherm was fitted well by the Langmuir model, indicating possible mono-layer biosorption of Cd and Cu on the immobilized . Moreover, the immobilized after the sorption of Cd and Cu could be regenerated and reused.

关键词： Saccharomyces cerevisiae (S. cerevisiae)     biosorption     heavy metals     immobilization     desorption    

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Biosorption of Cr(VI) by carbonized

Jinfa CHEN,Ping YANG,Dagang SONG,Sha YANG,Li ZHOU,Lei HAN,Bo LAI

《环境科学与工程前沿（英文）》 2014年 第8卷 第6期   页码 960-966 doi: 10.1007/s11783-013-0612-2

摘要： High quality and low cost carbon can be prepared from ( ) and Buckwheat straw. The biosorbent was used for Cr(VI) removal. The effect of experimental parameters, such as pH, sorbent dosage and temperature were examined and the optimal experimental condition was determined. Solution pH is found influencing the adsorption. Cr(VI) removal efficiency is found to be maximum (98%) at pH= 1. Langmuir and Freundlich adsorption isotherms were applicable to the adsorption process and their constants were evaluated. The adsorption data obtained agreed well with the Langmuir sorption isotherm model. The maximum adsorption capacities for Cr(VI) ranged from 46.23 to 55.19 mg·g for temperature between 298 K and 308 K under the condition of pH= 1.0. Thermodynamic parameters such as free energy change ( ), enthalpy ( ) and entropy ( ) indicate a spontaneous, endothermic and increased randomness nature of Cr(VI) adsorption. Studies found that the raw and buckwheat straw mixed materials with simple treatment had a high efficiency for the removal of Cr(VI) and would be a promising adsorbent.

关键词： Eupatorium adenophorum     buckwheat straw     adsorption     Cr(VI)     thermodynamics    

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Biosorption of Cr(III) from aqueous solution by freeze-dried activated sludge: Equilibrium, kinetic and

Qian YAO, Hua ZHANG, Jun WU, Liming SHAO, Pinjing HE,

《环境科学与工程前沿（英文）》 2010年 第4卷 第3期   页码 286-294 doi: 10.1007/s11783-010-0025-4

摘要： Batch biosorption experiments were conducted to remove Cr(III) from aqueous solutions using activated sludge from a sewage treatment plant. An investigation was conducted on the effects of the initial pH, contact time, temperature, and initial Cr(III) concentration in the biosorption process. The results revealed that the activated sludge exhibited the highest Cr(III) uptake capacity (120 mg·g) at 45°C, initial pH of 4, and initial Cr(III) concentration of 100 mg·L. The biosorption results obtained at various temperatures showed that the biosorption pattern accurately followed the Langmuir model. The calculated thermodynamic parameters, Δ (−0.8– −4.58 kJ·mol), Δ (15.6–44.4 kJ·mol), and Δ (0.06–0.15 kJ·mol·K) clearly indicated that the biosorption process was feasible, spontaneous, endothermic, and physical. The pseudo first-order and second-order kinetic models were adopted to describe the experimental data, which revealed that the Cr(III) biosorption process conformed to the second-order rate expression and the biosorption rate constants decreased with increasing Cr(III) concentration. The analysis of the values of biosorption activation energy ( = −7 kJ·mol) and the intra-particle diffusion model demonstrated that Cr(III) biosorption was film-diffusion-controlled.

关键词： activated sludge     biosorption     chromium     film diffusion     kinetics     thermodynamics    

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Efficient acetylene/carbon dioxide separation with excellent dynamic capacity and low regeneration energy

《化学科学与工程前沿（英文）》   页码 1616-1622 doi: 10.1007/s11705-022-2183-x

摘要： Adsorptive separation of acetylene/carbon dioxide mixtures by porous materials is an important and challenging task due to their similar sizes and physical properties. Here, remarkable acetylene/carbon dioxide separation featuring a high dynamic breakthrough capacity for acetylene (4.3 mmol·g–1) as well as an ultralow acetylene regeneration energy (29.5 kJ·mol–1) was achieved with the novel TiF62–-pillared material ZU-100 (TIFSIX-bpy-Ni). Construction of a pore structure with abundant TiF62– anion sites and pores with appropriate sizes enabled formation of acetylene clusters through hydrogen bonds and intermolecular interactions, which afforded a high acetylene capacity (8.3 mmol·g–1) and high acetylene/carbon dioxide uptake ratio (1.9) at 298 K and 1 bar. Moreover, the NbO52– anion-pillared material ZU-61 investigated for separation of acetylene/carbon dioxide. In addition, breakthrough experiments were also conducted to further confirm the excellent dynamic acetylene/carbon dioxide separation performance of ZU-100.

关键词： adsorption     acetylene/carbon dioxide separation     dynamic capacity     anion-pillared hybrid material    

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Buffer capacity of granular matter to impact of spherical projectile based on discrete element method

Ying YAN, Pengfei LI, Shunying JI

《结构与土木工程前沿（英文）》 2013年 第7卷 第1期   页码 50-54 doi: 10.1007/s11709-013-0186-x

摘要： Granular matter possesses impact-absorbing property due to its energy dissipation character. To investigate the impact-absorbing capacity of granular matter, the discrete element method (DEM) is adopted to simulate the impact of a spherical projectile on to a granular bed. The dynamic responses of the projectile are obtained for both thin and thick granular bed. The penetration depth of the projectile and the first impact peak are investigated with different bed thicknesses and impact velocities. Determining a suitable bed thickness is crucial to the buffering effect of granular matter. The first impact peak is independent of bed thickness when the thickness is larger than the critical thickness.

关键词： granular matter     impact peak     buffer capacity     discrete element method     critical thickness    

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Dynamic simulation of urban water metabolism under water environmental carrying capacity restrictions

Weihua ZENG,Bo WU,Ying CHAI

《环境科学与工程前沿（英文）》 2016年 第10卷 第1期   页码 114-128 doi: 10.1007/s11783-014-0669-6

摘要： A revised concept for urban water metabolism (UWM) is presented in this study to address the inadequacies in current research on UWM and the problems associated with the traditional urban water metabolic process. Feedback loops can be analyzed to increase the water environmental carrying capacity (WECC) of the new urban water metabolism system (UWMS) over that of a traditional UWMS. An analysis of the feedback loops of an UWMS was used to construct a system dynamics (SD) model for the system under a WECC restriction. Water metabolic processes were simulated for different scenarios using the Tongzhou District in Beijing as an example. The results for the newly developed UWM case showed that a water environment of Tongzhou District could support a population of 1.1926 × 10 , an irrigation area of 375.521 km , a livestock of 0.7732 × 10 , and an industrial value added of ¥193.14 × 10 (i.e. about US$28.285× 10 ) in 2020. A sensitivity analysis showed that the WECC could be improved to some extent by constructing new sewage treatment facilities or by expanding the current sewage treatment facilities, using reclaimed water and improving the water circulation system.

关键词： urban water metabolism system (UWMS)     system dynamic simulation     water environmental carrying capacity (WECC)     feedback loops     bilateral control    

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Polypropylene microplastics alter the cadmium adsorption capacity on different soil solid fractions

《环境科学与工程前沿（英文）》 2022年 第16卷 第1期   页码 3-3 doi: 10.1007/s11783-021-1437-z

摘要：

Microplastics (MPs) are widely present in a variety of environmental media and have attracted more and more attention worldwide. However, the effect of MPs on the interaction between heavy metals and soil, especially in soil solid fraction level, is not well understood. In this study, batch experiments were performed to investigate the adsorption characteristics of Cd in bulk soil and three soil solid fractions (i.e. particulate organo matter (POM), organic-mineral compounds (OMC), and mineral) with or without polypropylene (PP) MPs.

关键词： Polypropylene microplastics     Cadmium     Adsorption     POM     OMC     Mineral    

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Analytical algorithms of compressive bending capacity of bolted circumferential joint in metro shield

《结构与土木工程前沿（英文）》   页码 901-914 doi: 10.1007/s11709-023-0915-8

摘要： The integrity and bearing capacity of segment joints in shield tunnels are associated closely with the mechanical properties of the joints. This study focuses on the mechanical characteristics and mechanism of a bolted circumferential joint during the entire bearing process. Simplified analytical algorithms for four stress stages are established to describe the bearing behaviors of the joint under a compressive bending load. A height adjustment coefficient, α, for the outer concrete compression zone is introduced into a simplified analytical model. Factors affecting α are determined, and the degree of influence of these factors is investigated via orthogonal numerical simulations. The numerical results show that α can be specified as approximately 0.2 for most metro shield tunnels in China. Subsequently, a case study is performed to verify the rationality of the simplified theoretical analysis for the segment joint via numerical simulations and experiments. Using the proposed simplified analytical algorithms, a parametric investigation is conducted to discuss the factors affecting the ultimate compressive bending capacity of the joint. The method for optimizing the joint flexural stiffness is clarified. The results of this study can provide a theoretical basis for optimizing the design and prediciting the damage of bolted segment joints in shield tunnels.

关键词： shield tunnel     segment joint     joint structural model     failure mechanism    

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A method to calculate working capacity space of multi-DOF manipulator and the application in excavating

Baochen WEI, Feng GAO

《机械工程前沿（英文）》 2012年 第7卷 第2期   页码 109-119 doi: 10.1007/s11465-012-0323-6

摘要：

Working capacity refers to the velocity output and force output of a manipulator. It is usually be represented by output capacity space. In this paper, the method of Linear Programming and a geometric method are proposed to calculate working capacity spaces in different situations. With the consideration of gravity effect of every component, the output force capacity space of heavy duty manipulators is calculated. The results show that the effect of the gravity is a translation of the capacity space. This paper gives a method for the output capacity express especially for heavy duty manipulators. The output capacity space can be helpful to the driving parameters selection. With the consideration of the gravity effect of every component and the friction at the joints, the excavating force capacity space of the heavy-load excavating mechanism is calculated and is represented as a multi-dimensional polytope. The results show that the effect of the gravity and friction is to translational act on the capacity space.

关键词： working capacity     multi-DOF manipulator     capacity polytope     excavating mechanism    

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Foundations bearing capacity subjected to seepage by the kinematic approach of the limit analysis

Mehdi VEISKARAMI, Ghasem HABIBAGAHI

《结构与土木工程前沿（英文）》 2013年 第7卷 第4期   页码 446-455 doi: 10.1007/s11709-013-0227-5

摘要： An estimate of the ultimate load on foundations on soil layers subject to groundwater flow has been presented. The kinematic approach of the limit analysis was employed to find the upper-bound limit of the bearing capacity. Both smooth and rough base strip foundations were considered associated with different collapse patterns. Presence of the groundwater flow leads to a non-symmetric collapse pattern, i.e., a weak side and a strong side in two-sided collapse patterns, depending on the direction of the flow. It was found that the bearing capacity has a decreasing trend with increase in the groundwater flow gradient and hence, a reduction factor has been introduced to the third term in the bearing capacity equation as a function of the flow gradient.

关键词： foundation     bearing capacity     limit analysis     numerical computation     plasticity     seepage    

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Analysis on shear capacity of prestressed concrete spatial connections

XUE Weichen, LIU Zhenyong, JIANG Dongsheng

《结构与土木工程前沿（英文）》 2008年 第2卷 第4期   页码 309-317 doi: 10.1007/s11709-008-0052-4

摘要： Based on experimental results of prestressed concrete spatial connections, nonlinear finite element models were established to analyze the shear capacity of spatial connections and parametric studies were performed using ANSYS. It is found that the shear capacity of spatial connection is influenced by joint hoop, beam prestress, column compressive load, and direction of resultant shear force. The parametric studies also indicate that the shear capacity of spatial connection under biaxial cyclic loading is lower than that of corresponding connections under plane loading. A design formula for calculating the shear capacity of spatial connections is proposed based on the parametric studies and verified by the available test results.

关键词： available     direction     nonlinear     capacity     compressive    

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标题 作者 时间 类型 操作

The biosorption of Cr(VI) ions by dried biomass obtained from a chromium-resistant bacterium

Paul Fabrice NGUEMA,Zejiao LUO,Jingjing LIAN

期刊论文

Biosorption of Cu(II) to extracellular polymeric substances (EPS) from

Xiangliang PAN, Jing LIU, Wenjuan SONG, Daoyong ZHANG

期刊论文

Biosorption of mercury and lead by aqueous

Pratibha SANJENBAM, Kumar SAURAV, Krishnan KANNABIRAN

期刊论文

Biosorption and biotransformation of crystal violet by

Tao PAN, Suizhou REN, Jun GUO, Meiying XU, Guoping SUN

期刊论文

Biosorption of Cd

Fengyu ZAN, Shouliang HUO, Beidou XI, Xiulan ZHAO

期刊论文

Biosorption of Cr(VI) by carbonized

Jinfa CHEN,Ping YANG,Dagang SONG,Sha YANG,Li ZHOU,Lei HAN,Bo LAI

期刊论文

Biosorption of Cr(III) from aqueous solution by freeze-dried activated sludge: Equilibrium, kinetic and

Qian YAO, Hua ZHANG, Jun WU, Liming SHAO, Pinjing HE,

期刊论文

Efficient acetylene/carbon dioxide separation with excellent dynamic capacity and low regeneration energy

期刊论文

Buffer capacity of granular matter to impact of spherical projectile based on discrete element method

Ying YAN, Pengfei LI, Shunying JI

期刊论文

Dynamic simulation of urban water metabolism under water environmental carrying capacity restrictions

Weihua ZENG,Bo WU,Ying CHAI

期刊论文

Polypropylene microplastics alter the cadmium adsorption capacity on different soil solid fractions

期刊论文

Analytical algorithms of compressive bending capacity of bolted circumferential joint in metro shield

期刊论文

A method to calculate working capacity space of multi-DOF manipulator and the application in excavating

Baochen WEI, Feng GAO

期刊论文

Foundations bearing capacity subjected to seepage by the kinematic approach of the limit analysis

Mehdi VEISKARAMI, Ghasem HABIBAGAHI

期刊论文

Analysis on shear capacity of prestressed concrete spatial connections

XUE Weichen, LIU Zhenyong, JIANG Dongsheng

期刊论文