Since solar power was introduced into the microbial fuel cell (MFC) field, there is great interest in microbial electrochemical-photoelectrochemical synergetic systems used for electrogenesis, fuel production or environmental cleaning. Metal oxide is a common medium in solar power conversion. Research on interaction between microorganism and metal oxide is necessary to understand synergy mechanism or enhance efficiency. In this paper, various interactions between microorganism and metal oxide are summarized according to physical absorption, microbial weathering, microbial mining, photocatalytic sterilization and microbe-metal oxide synergistic effects, providing a reference for the construction of efficient microbial electrochemical-photoelectrochemical synergetic systems.

Oxidative reforming (partial oxidation) of fuel is mildly exothermic and has the advantages of fast reaction and low energy cost, which is especially suitable for on-line production of H₂ or H₂-rich gas. Atmospheric-pressure non-thermal plasma provides a very promising new technology for oxidative reforming of fuel with significant advantages of feed flexibility, fast response, and compact, efficient reactor. The recent developments of atmospheric pressure non-thermal plasma reactors for oxidative reforming of hydrocarbon fuel are reviewed. The warm plasma generated by spark and gliding arc discharges and its fuel reforming reactors are presented. Compared with the reactors of cold plasma generated by corona and dielectric barrier discharges, the warm plasma reactor exhibits high fuel conversion as well as low energy cost.

Particle discharging from concentric and eccentric wedge shaped hoppers with different internal friction coefficients, hopper half angles and hopper widths was simulated by 3D discrete element method (DEM) and the effect of wall friction coefficient on discharging rate were investigated. In general, increasing wall friction coefficient would decrease discharging rate by retarding particle-wall slip, and the effect was more significant in wedge shaped hoppers. The friction coefficient in the convergent section had a stronger effect in reducing discharging rate than that in the vertical section. When internal friction coefficient decreased, or the width of the hopper increased, the retarding effect would decrease and eventually become insignificant.

A slag flow model was developed for the membrane wall gasifier by coupling the 3D gasifier model, the one-dimensional slag model and the particle trap model. The influence of particle behavior and O/C (ratio of oxygen to coal) on slagging of gasifier was demonstrated. Differences between membrane wall gasifier and refractory wall gasifier were shown. The larger particle benefited the capture efficiency and formation of slag layer, while the smaller one favored high carbon conversion. The thermal resistance of solid slag layer accounted for a large proportion in the membrane wall gasifier, thus it could protect silicon carbide layer and membrane wall from thermal corrosion.

Fluid macro-instability is a large scale low frequency transient quasi-periodic phenomenon existing in stirred vessel, and affects fluid energy and mass transfer behavior. To reveal the nature of unsteady flow in a stirred vessel with double rigid-flexible impeller, tap water was used as working fluid, and wavelet analysis and flow field visualization were adopted to analyze the influence of double rigid-flexible impeller on the frequency of macro-instability. The difference between double rigid and double rigid-flexible impellers was analyzed in terms of mixing performance. The frequency of macro-instability increased linearly with agitation speed. At agitation speed 180 r·min^-1, macro-instability frequency values of rigid-flexible impeller were 0.5096 Hz and 0.3459 Hz with off-bottom clearance 0.33T and 0.5T, respectively. Compared with double rigid impeller system, mixing time was shortened by about 22.5% and 35%, respectively. But macro-instability with off-bottom clearance 0.25T disappeared and bands phenomenon appeared. Shortening the off-bottom clearance could reduce the regular area. Double rigid-flexible combination impeller regulated fluid macro-instability and strengthened energy transfer behavior, so as to shorten mixing time and improve mixing efficiency of the fluid.

In order to study the flow characteristic of gas-liquid-solids three-phase in the process of gas-solids two-phase flow passing through the liquid bath, an experimental platform and a numerical simulation platform based on the Euler-Lagrange method were established respectively to conduct the studies on three-phase flow and particles movement. The distribution characteristics and the movement of three typical particle sizes were obtained, such as 5—15 μm, 80—110 μm and 380—530 μm. The results of experiment were consistent with the results of numerical simulation. A multi-peak distribution of particle concentration existed in the liquid bath along the axial and radial directions. The particles of 5—15 μm in diameter were more easy to follow gas, and their distribution was more uniform. The particles of 380—530 μm in diameter were more difficult to follow gas, and their distribution was mainly concentrated at the bottom of the liquid bath. The increase of static submerged depth of downcomer outlet made the concentration distribution of particles more smoothly in the liquid bath.

To investigate the influence of current density on transfer characteristics in the electrolysis cell of chlor-alkali industry, the fluid flow, heat and mass transfer of anode chamber at different current densities were simulated numerically using computational fluid dynamics software. The distributions of velocity, temperature and concentration in a grille of the anode chamber were obtained. Taking liquid circulation rate, maximum velocity near the membrane, temperature and concentration at the membrane surface as indices, the performance of the electrolysis cell at different current densities was evaluated. Liquid circulation rate and temperature of membrane surface increased and concentration of brine decreased with increasing current density. Under typical working conditions for current density of 4.5 kA·m^-2, average temperature of the electrolysis cell and of the membrane surface were 86.39℃ and 87.40℃, respectively. Average temperatures of the electrolysis cell and the membrane surface could be maintained at the values of the typical working conditions by lowering inlet temperature of brine when current density increased.

An experiment was conducted to study the heat transfer characteristics of supercritical pure R41, mixtures of CO₂/R41 (20.5/79.5), and CO₂/R41 (51.4/48.6) cooled in a horizontal smooth mini-channel tube with inner-diameter of 2 mm. Mass flow rate was in the range of 400 to 800 kg·m^-2·s^-1, pressure changed from 6.0 to 8.0 MPa,heat flux ranged from 12 to 48 kW·m^-2 and bulk temperature varied from 20℃ to 80℃. The maximum heat transfer coefficient (α) of the three fluids increased with the CO₂ mass fraction. Additionally, α of pure R41 is smaller than that of the mixtures. However, α variation tendency of the mixtures is the same as that of pure R41. α of the three working fluids are ranging from 2 kW·m^-2·K^-1 to 25 kW·m^-2·K^-1 under the present test condition. The influence of pressure is significant. The closer of the pressure approaches the critical pressure, the higher of the maximum α is. The heat flux has little influence on α when the bulk temperature is far away from the critical temperature. However for the bulk temperature near the critical temperature, α increases with the decrease of heat flux. The experimental results are compared with prediction values calculated by twelve correlations. It is concluded that four correlations predicting with good precisions, and the errors are within ±30%. Nevertheless, the prediction errors increase with CO₂ mass fraction.

For gas-liquid bubble column with dense vertical bundle internals, the resistance force of bundles on gas and liquid phases was taken into account in the two-phase Euler axisymmetric k-ε model. By introduction of corresponding momentum source, turbulence source and dissipation source, a 2-D CFD model of bubble column with bundle internals was established. The model could clearly and accurately demonstrate the features of gas-liquid flow in bubble column with bundles: "funnel effect" and extension of sparger zone. The calculated two-dimensional distributions of hold-up and liquid velocity agreed with experimental data within a wide range of superficial gas velocity (0.12—0.62 m·s^-1).

In order to understand natural convection heat transfer of molten nitrate, natural convection heat transfer of lithium nitrate (LiNO₃) and multi-components nitrate around a horizontal cylinder with different diameters (0.1, 0.4, 1, 4, 10, 40 mm) at different medium temperatures (573, 623, 673 K) was studied by simulation. The results fitted best with the Fand's correlation comparing with different classic correlations. After analysis of all calculated data, a simple correlation was proposed for predicting laminar natural convection heat transfer of molten nitrate around a horizontal cylinder. Compared with the natural convection experiment data of LiNO₃, the proposed correlation had a maximum uncertainty of ±20%, and the reliability of the proposed correlation was verified.

Accurate measurement of temperature distribution of pipe surface becomes the key issue for optimization of heating process in tubular furnace. Experiment research of visualization of pipe temperature distribution was conducted on an industrial ethylene cracking furnace based on radiation image processing. Inside the furnace pipe, thermal cracking reaction of naphtha occurs, whose reaction heat is provided by eight burners located on the bottom, and the fuel is natural gas. Coking of furnace pipe was ignored in the model. In order to deal with the radiative heat transfer equation with complex boundary condition in the tubular furnace, a DRESOR method based on Monte Carlo principle was used, and the radiations from tubes, flame and furnace wall were decoupled. Sixteen CCD cameras were mounted on the furnace wall in order to capture the flame image which was transferred into boundary radiation intensity distribution by blackbody calibration. A revised Tikhonov regularization method was used to solve the morbid radiation image equation, and the distributions of pipe temperature and heat flux were measured online and their variation trends with flow direction of naphtha were also discussed. Validated by two different methods, temperature reconstruction error was less than 2% and maximum deviation was within 20K, and the major error occurred on the maximum and minimum temperature areas. This study would be useful for adjustment of combustion and heating process in tubular furnace, and would improve the uniformity of pipe surface temperature in order to extend their working life.

For the spiral winding variable frequency electromagnetic water processor, magnetic induction intensity of water in processing cavity and induced current were analyzed with ANSYS simulation software. The inner relationship of magnetic induction intensity and induced current work with excitation signal frequency was studied. Using an online evaluation test bench for electromagnetic scale inhibition, the influence of spiral winding processing cavity frequency on scale inhibition of hard water circulation heat transfer experiment pipe was observed, and the ideal scale inhibition frequency was determined. Under this experimental condition, the frequency near the line frequency had longer scale induction period and stronger scale inhibition effect, and anti-scaling efficiency was the best.

The process of methyl nitrite (MN) regeneration is a key step in scale-up of synthesis of alkyl esters. To maximize the real atom economy of the process, CO coupling reaction and MN regeneration need to be optimized and proceed at the same reaction rate. Studies on the process and kinetics of MN regeneration are reported. But few mathematical models for MN regeneration in a packed column are available. By analyzing the important reactions of MN regeneration, a mathematic model of MN regeneration in a packed column was developed with the reported kinetic parameters. The effect of main reaction parameters on MN yield was studied. The simulation results showed that MN yield increased with increasing liquid velocity and NO/O₂ mole ratio but decreased with increasing temperature, gas velocity and N₂ volume fraction. The simulation results were verified by experiments under different conditions, which proved that this model could be used for the design and operation of MN regeneration. Furthermore, the simulation results at two different mixing modes of NO and O₂ were presented.

The effects of the initial concentration of effective alkali, H factor (ie, coupled time and temperature) on methanol formation in the eucalyptus pulping and residual alkali concentration in the pulping effluents were investigated. It was found that there existed a linear relationship between the effective alkali concentration and negative exponent of H factor for pulping process. From this observation, a mathematical model that takes account for the time-dependent concentration of effective alkali was established from the kinetic analysis for wood demethoxylation during pulping process. The results showed that the proposed model could predict methanol formation in kraft pulping at various process conditions with a good accuracy (R² = 0.990). It was found from the results predicted by this model that the methanol formation was much more sensitive to pulping temperature than to initial concentration of effective alkali. The prediction of this model for formation amount of methanol at various process conditions could be a good guidance for control and reduction of methanol formation per unit mass removal of lignin in pulping process.

Electrolyzed oxidizing water (EOW), as an innovative disinfectant characterized by its high efficiency, broad antimicrobial spectrum, and non-toxic residues, has been broadly used in health care industry, medicines, agriculture, and food processing. EOW is usually generated by electrolysis of a dilute NaCl solution in a chamber with two cells separated by membrane, and is obtained from the anode side. But low current efficiency and short service life of the anode in EOW generators restrict the application of EOW. Ir_0.5Pt0_.5O₂ anode was prepared by the improved Adams fusion method. The properties of Ir_0.5Pt_0.5O₂ anode was investigated with X-ray diffraction (XRD), scanning electron microscope (SEM) and electrochemistry cyclic voltammetry (CV). The crystal type is rutile with (101), (002) and (301) crystal planes. A large number of cellular structures were observed on the surface of the anode, which greatly increased specific surface area of the anode. With increasing specific surface area, electric charge was enhanced to 0.4 mC, which was 2.65 times of pure IrO₂. Electrochemical characteristics of the anode surface, such as oxidation peaks at 1.0 V(Pt-OH) and 0.9 V(Ir³⁺/Ir⁴⁺) proved the formation of platinum iridium oxide. The activities of chlorine evolution and oxygen evolution were also studied through linear sweep voltammetry (LSV). Compared with IrO₂, chlorine evolution activity in unit apparent surface area increased significantly, but oxygen evolution activity decreased obviously. The slope of Tafel was 56.3 mV·dec^1- for chlorine evolution reaction (CER), and the mechanism was Volmer-Heyrovsky in which the rate controlling step was electrochemical desorption. The slope of Tafel was 126.6 mV·dec^1- for oxygen evolution reaction (OER), and the rate controlling step was formation of surface hydroxide on the catalyst surface. Electrochemical surface structure and electrochemical performance of Ir_0.5Pt_0.5O₂ oxide coatings in 1 g·L^-1 NaCl solution were investigated with electrochemical impedance spectroscopy (EIS). CER activity of Ir_0.5Pt_0.5O₂ was better than IrO₂, which was in agreement with previous research. In the actual EOW preparation, electrolysis efficiency and available chlorine content (ACC) of EOW on the Ir_0.5Pt_0.5O₂ anode were much greater than IrO₂ anode under the same condition. The accelerated life of Ir_0.5Pt_0.5O₂ anode was 3.14 times of the IrO₂ anode and the performance of the anode was greatly improved, which favored its commercial use.

Dissolution rate of a gypsum (CaSO₄·2H₂O) sample rotating in pure water was measured by automatically detecting electric conductivity of the solution, in one-second time interval of data acquisition. Superficial shape (7 cm×4 cm×2 cm) and surface area (100 cm²) of the sample were maintained constant basically during measurement. Under surface reaction-controlled dissolution experiment condition, the kinetics model was used for regression of dissolution rate constant (k_s) and reaction order (n). The values of k_s were 1.91×10^-8, 3.46×10^-8, 4.92×10^-8, 7.07×10^-8 mol·cm^-2·s^-1 respectively for temperatures 25, 45, 65, 85℃, accommodated by a value of 1.27 for reaction order n. Consequently activation energy of dissolution reaction was correlated 19.07 kJ·mol^-1 through the Arrhenius equation. Because of eliminating uncertainty of sample's surface area in dissolution experiment, the results calculated from the kinetics equation with the model parameters regressed in this paper were more consistent with experimental value and closer to theoretical expectation of dissolution rates in literature.

To intensify the CO₂ absorption process, a reactor based on swirling and multi-staged liquid-gas contact was used to examine the mass transfer performance of long-concentration span CO₂ (2.5%—15%) capture with NaOH solution. The effects of absorbent concentration, absorbent flow rate, CO₂ concentration, gas flow rate and reaction temperature on volumetric overall mass transfer coefficient (K_ga) were experimentally investigated. The mass transfer coefficient varied from 4.53×10^-5 to 9.22×10^-5 kmol·m^-3·s^-1·kPa^-1 under the experimental conditions. Compared with axial spray with double stages and swirling spray with single stage, swirling-based multi-staged spray reactor was able to effectively enhance the performance of absorption of long-concentration span CO₂. A high concentration and a high flow rate of the absorbent, and a high reaction temperature helped to increase K_ga. K_ga increased with the increase of CO₂ concentration, but decreased while CO₂ concentration was more than 5%. K_ga increased and then stabilized with increase of gas flow rate.

Based on the principle of calcified roasting and E-pH diagram of acid leaching, the loss of vanadium and iron in calcified roasting and acid leaching were investigated with vanadium-bearing titanomagnetite as raw material and calcium sulfate as calcification agent. The vanadium extraction process combining calcified roasting and acid leaching was feasible in theory. The loss ratio of vanadium in pellets increased with increasing temperature in the calcified roasting process. Despite some loss of vanadium the calcified roasting process was favorable to the subsequent acid leaching of vanadium. The leaching ratio of vanadium increased with increasing roasting temperature below 1450 K. The leaching ratio reached a maximum at 1450 K, and then it decreased. The leaching ratio of vanadium had no obvious change with increasing sulfuric acid concentration. At the same time, the loss ratio of iron in the leaching process increased rapidly when roasting temperature was higher than 1450 K, and it also increased with increasing concentration of sulfuric acid. By controlling experimental conditions, the leaching ratio of vanadium in vanadium-bearing titanomagnetite could reach 79.08% but the loss ratio of iron was 3.32%.

The wiper can enhance mass transfer efficiency of molecular distillation device. Based on the structural relationship between feed flow rate, liquid concentration, motor speed, evaporator size and other factors, a mathematical model of wiped film molecular distillation was established with the roller wiper as research object. By substituting the experimental parameters into the model, the effluent concentrations after molecular distillation could be calculated quickly, and the results were compared with actual concentrations with error range reduced to 1.5%—2.5%. The model provided a reference for optimal control conditions. The parameters could be adjusted by MATLAB. The influence of each structure parameter on the molecular distillation process was studied, and knowledge of changing tendency of simulation image helped to accurately determine specific detail in the design of molecular distillation device, providing a basis for wiped film molecular distillation device design.

In the high-level radioactive waste liquid separation process of spent fuel reprocessing, new separation materials are of great significance for the efficient extraction of strontium. In the paper, 1, 2-alternate thiacalix[4]biscrowns 4 (TCACE) was synthesized by using calix[4]arene and triethylene glycol di(p-toluenesulfonate). TCACE was characterized by FT-IR, ¹H NMR and MS. The influence of different diluents on extraction rate was studied, and CH₂Cl₂ was chosen as diluent by optimization. Extraction rate of Sr²⁺ was excellent and average mass transfer coefficient was 1.36×10^{-5 m}·s^-1 under the conditions of CH₂Cl₂ as organic solvent, nitrate acid concentration was 3 mol·L^-1, TCACE concentration was 1×10^-3 mol·L^-1, Sr²⁺ concentration was 5×10^-4 mol·L^-1, extraction was conducted for 80 min and at 25℃. Different technological conditions on extraction for Sr²⁺ were studied. Furthermore, the extraction measurement equation was also studied. The extraction complex was {Sr(NO₃)₂}·{TCACE} as shown by experiment. The extraction effects for other metal ions Mo⁶⁺, Ni²⁺, Ag⁺, Sn⁴⁺ with TCACE were also studied. It was found that TCACE showed excellent selectivity for Sr²⁺.

Quaternary ammonium salts cation and montmorillonite nanocomposites (C_nTA⁺/montmorillonite nanocomposites) were prepared from a series of quaternary ammonium salts with the same structure but different alkyl carbon chain lengths to adsorb phthalate ester (PAEs) in aqueous solution. The effects of C_nTA⁺/montmorillonite nanocomposites prepared with different alkyl carbon chain lengths and amounts of quaternary ammonium salts on PAEs adsorption efficiency were investigated. C_nTA⁺/montmorillonite nanocomposites as-prepared could adsorb PAEs effectively. Alkyl carbon chain length and amount of quaternary ammonium salts both affected adsorption results. At a smaller amount of quaternary ammonium salts, the adsorption removal of PAEs increased with increasing alkyl chain length of quaternary ammonium salts. However, at a larger amount of quaternary ammonium salts, the adsorption removal of PAEs increased firstly and then decreased with increasing alkyl chain length of quaternary ammonium salts.

Selection of working fluid is one of the key issues in the organic Rankine cycle (ORC) waste-heat power generation technology. Multi-criteria methods for working fluid selection are urgent to be studied. Existing researches are mostly under the constraints of specific thermodynamic and structural conditions. Contradictory findings exist in many studies, because there is no general optimization method for ORC working fluid selection. A method using multi-level fuzzy optimization and non-structural fuzzy decision was developed to solve the problem. Comprehensive considerations of technical,economic performance and environmental protection of ORC systems are presented. Since the factors that influence ORC working fluid selection are multi-level and non-structural,establishment of a three-level fuzzy optimization model to obtain a more satisfactory result is preferable.

Al-Si-Cr coating was prepared on the surface of 25Cr35NiNb alloy by pack cementation, and its anti-coking properties were studied by coking experiment using ethylene cracking test apparatus. The microstructure of coating and the morphology of coke were investigated with metallurgic microscope, electronic scanning microscope (SEM) and energy dispersive X-ray spectrometer (EDS). Al-Si-Cr coating with thickness of about 130 mm was obtained by pack cementation. The coating had multiple layers with dense structure, consisting of an outer layer composed of aluminum-silicon-rich compounds and an inner layer composed of chromium- silicon-rich compounds. The Al-Si-Cr coating had excellent coking inhibiting properties. It could inhibit catalytic coking effectively, and the rate of coke inhibition was up to 72.5%.

A broad range of inhibitors in hydrolysate of lignocellulose, including weak acids, furan derivatives and phenolic compounds restrain yeast growth and subsequent fermentation. The effect of oxido-reduction potential (ORP) regulation on yeast cell tolerance to the presence of acetic acid, furfural and phenol was investigated. Cell growth and metabolite distribution changed under different ORP levels [(305±5) mV, (157±8) mV and (-150±5) mV] by feeding oxidant (potassium ferricyanide, K₃[Fe(CN)₆]) and reductant (dithiotreitol, DTT). Compared to the control group, cell growth was enhanced, and ethanol yield increased except for phenol group. The yield of glycerol was enhanced under both oxidizing and reducing conditions, since glycerol was a main protective molecule in yeast. High ORP level facilitated detoxification of inhibitors thanks to high biomass accumulation.

A PAH-degrading strain JI 2 was isolated from oilfield produced water in Mao 8 block of Zhongyuan Oilfield. According to analysis of morphological observation, physiological and biochemical test, 16S rRNA gene, house-keeping genes and DNA-DNA hybridization, JI 2 was considered to represent a novel species of the genus Microbacterium. The strain could not only grow in inorganic salt culture medium and utilize naphthalene and pyrene as the sole carbon source, but also degrade mixed naphthalene, phenanthrene, anthracene and pyrene. The four PAHs degradation rates could reach 61.4%, 86.6%, 69.9% and 18.6%, respectively after 7 d. The viscosity of crude oil treated with JI 2 decreased by 29.3% and degradation rate was 134 mg·d^-1. Fourier transform infrared spectra, group composition and GC-MS analysis of the crude oil treated with JI 2 showed that the strain tended to utilize PAHs in aromatic hydrocarbons and resins in crude oil. The relative contents of naphthalene series, phenanthrenseries, thiophene series, fluorene series and chrysene series, C21-triaromatic steroid, pyrene, and benz(a)pyrene decreased after degradation. JI 2 had the capacity to remediate water and soil environment contaminated by PAHs and oil, and provided a feasible way for bioremediation of PAHs and oil pollution.

Steam is present in combustion flue gas, oxy-fuel combustor/calciner and fuel gas. Some previous works in this field have examined the reactivity of calcium oxide in the presence of steam. There is general agreement that the presence of steam increases the rate of carbonation even at low concentrations. However, there is no description about the effect of steam on the carbonation reaction of calcined limestone. The effects of temperature, concentration of steam on carbonation were investigated in a thermogravimetric analyzer. The understanding of the mechanisms participating in the carbonation reaction could be arrived at through the use of model interpretations of the rate controlling process. The experimental data were analyzed by means of the random pore model. During carbonation reaction, a very initial rapid reaction was followed by the second stage of the reaction occurring in the next slower regime. The experiment results showed that the effect of steam on carbonation could be neglected during the first stage of reaction. However, the conversion of carbonation in the presence of 1.5%(vol), 10%(vol) and 20%(vol) steam were 19.8%, 27.2% and 30.5% higher than the conversion without steam after 10 min during the second stage of reaction at 500℃. Steam was beneficial to enhancing the conversion of carbonation, but the extent of increase became not significant with increasing concentration of steam. The linearity of the second stage reaction data strongly suggested that this stage was controlled by a diffusion process occurring in a layer of calcium carbonate surrounding the calcium oxide in the pores of the solid. The parameters related to effective product layer diffusivities were plotted in Arrhenius form and the changes in activation energy at various steam concentrations were also shown. Comparison with the experimental effective diffusivities calculated for the carbonation reaction showed that the activation energies in the lower temperature range were in agreement with those obtained in the conductivity measurements. This suggested that the product layer diffusion process was proceeded by a mechanism similar to that of conduction in calcium carbonate. The activation energy of carbonation decreased from 179.9 kJ·mol^-1 to 237.7 kJ·mol^-1 when 1.5% steam was added according to the random pore model. The activation energy was 156.6 kJ·mol^-1 and 148.6 kJ·mol^-1 respectively for the atmospheres of 10% and 20% steam. There were two characteristics of product layer diffusion during carbonation. One was the slope of diffusional coefficient to increase from about 550℃, which was irrelevant to the presence of steam. The other was the effect of steam on carbonation to turn weak with increasing concentration of steam. At the higher temperature range, the possible mechanism for effective diffusion could be associated with sequential decompositions of carbonate ions in the calcium carbonate layer. A carbonate ion momentarily decomposed to generate carbon dioxide and an oxygen ion. The carbon dioxide molecule then moved to a neighboring similarly vacated site, while another carbon dioxide so generated elsewhere moved to take its place and reform the carbonate ion. In this way by a site to site random walk the carbon dioxide molecule diffused through the product layer, before reaction at the interface of calcium oxide and calcium carbonate. Such a mechanism appeared more prominent than the motion of carbonate ion at the higher temperature range. Both the above mechanisms for the diffusion stage were likely, and the true situation might involve one or a combination of both.

An organic Rankine cycle system with recuperator was designed for recycling waste heat of a vehicle diesel engine and R245fa was used as working medium. The change of waste heat from vehicle diesel engine under variable working conditions was studied. The operating performance of the organic Rankine cycle system with recuperator was analyzed under variable working conditions and the influence of degree of superheat on the organic Rankine cycle system with recuperator was discussed. Three evaluation indices, waste heat recovery efficiency (WHRE), engine thermal efficiency increasing ratio (ETEIR) and output energy density of working fluid (OEDWF) were presented for the vehicle diesel engine-organic Rankine cycle combined system. The net power output, WHRE and ETEIR could reach maximum values of 43.74 kW, 14.93% and 13.58%.

Pyrolysis experiments were conducted on a unit of thermogravimetric-infrared-mass spectrometry at heating rate of 20℃·min^-1 to examine the evolution characteristics of light gases from low temperature pyrolysis of oil shale obtained from four locations (FS, HD, MM and NM). The time-resolved light gases including H₂, H₂O, CO, CO₂, CH₄ and C_nH_m were investigated for their release rates and accumulated productions varying with the change of temperature. Light gases evolved at temperatures in the range of 180—540℃. Release rate curves for H₂, CH₄ and C_nH_m mainly resembled each other, appearing in Gaussian distribution. Release rate curves for CO and CO₂ smoothly increased first and then accelerated sharply. After reaching a maximum the curves dropped quickly till the end of evolution. Change of H₂O release rate was complicated. Release rates of internal water, mineral water and pyrolysis water of oil shale in three stages all increased to a maximum and then leveled off.

In this study, the effect of oxygen supply at the initial stage of anaerobic digestion on biogas production from corn straw was investigated in batch-tests. Cumulative methane yields were between 256.6 and 299.8 ml·(g VS)^-1. Maximum methane yield was obtained at oxygen load of 10 ml·(g VS)^-1, which was 8.4% higher than that of the untreated sample. When oxygen loads exceeded 40 ml·(g VS)^-1, slightly negative effect on methane yield was observed. The modified first order equation analysis indicated that oxygen supply treatment at the initial stage could accelerate hydrolysis of substrate. However, excessive oxygen supply during treatment might prolong the lag-phase time of anaerobic digestion. In addition, oxygen supply at the initial stage of anaerobic digestion could increase volatile solids degradation of corn straw.

Diffusion process of biogas and evaluation of methane oxidation in landfill cover soil are important parts of research on methane emission. Diffusion process of oxygen in landfill cover soil was analyzed by simulation, and an oxygen diffusion model fitted by exponential equation (0.8941<R²<0.9975) was developed. Potential of methane oxidation in different landfill cover depths was also investigated by analyzing organic carbon and monitoring methane concentration. The most intensive methane oxidation occurred at the layer of 0.05—0.25 m. An oxygen consumption flux model in landfill cover was derived on the basis of Fick's law and axial dispersion model. There was no significant difference between fitted values by oxygen consumption flux model and derived values by empirical equation of biological methane oxidation. Based on the above model, a methane consumption flux model was derived finally, and the prediction was consistent with detection. These results provided new ideas and theoretical basis for revealing biogas diffusion process in landfill cover soil, intensifying methane oxidation capability and predicting methane emission.

Nitrous oxide (N₂O) is one of the most important greenhouse gases, about 265 times stronger than carbon dioxide (CO₂), and it may also destroy the ozone layer. In the biological wastewater treatment process, autotrophic nitrification has been thought to be the major source of N₂O production. So it becomes increasingly important to prevent N₂O emission from sewage treatment. In this study, by adding NH₄⁺, NH₂OH and NO₂^- to the effluent, the effect of NO₂^- on N₂O production by NH₄⁺ and NH₂OH oxidation during the nitritation process was investigated in a laboratory batch-scale system with activated sludge for treating domestic wastewater. Within the first 30 min of NH₄⁺ and NH₂OH oxidation process (total test time:180 min) N₂O accounted for more than 25% of the total production. As NH₄⁺ or NH₂OH was consumed completely, the amount of N₂O net production reduced to less than 0.2 mg·L^-1 in the last 30 min. Furthermore, the concentration of NO₂^--N could affect N₂O production. The increase of NO₂^--N would promote generation of N₂O. The maximum total N₂O net production was 6.86 mg·L^-1 when the concentration of NO₂^- was 60 mg·L^-1. NH₂OH oxidation played a key role in N₂O production at the very beginning of the experiment while nitrifier denitrification became a main pathway later. When the domestic sewage was treated under DO limited conditions, due to the presence of COD, there might occur heterotrophic denitrification during the aeration phase. However, oxygen and NO₂^- had strong inhibition on the activity of nitrous oxide reductase (NOS), consequently N₂O could not be reduced to N₂ completely. It led to more than 17% N₂O was produced and the maximum total net production reached 11.07 mg·L^-1. Hence, the contribution to N₂O produced by denitrification could not be ignored during the domestic wastewater treatment. Besides co-existence of NH₄⁺ and NH₂OH could significantly increase N₂O production and this process also emitted more N₂O when the concentration of NO₂^- was increased.

The effects of aerobic starvation on nitrification bacteria's activity and sludge performance of filamentous bulking sludge were investigated in an aerobic-anoxic SBR process. Ammonia-oxidizing bacteria (AOB) had a higher hungry sensitivity than nitrite-oxidizing bacteria (NOB) in 14 days of aerobic starvation process which was kept aeration and without feed. The decay of AOB [(0.42±0.06) d^-1] was higher than NOB [(0.34±0.05) d^-1]. The phenomenon of nitrite accumulation was apparently achieved from the system in the early resuscitation period. This phenomenon was due to that AOB was able to keep their cells in a state of readiness where it was possible to start oxidizing ammonia almost immediately and with the maximum rate after shorter starvation periods. They were thereby able to respond rapidly to changing environmental conditions, which was reflected by the higher activity resuscitation rate of AOB than that of NOB. In addition, aerobic starvation could kill filamentous bacteria and improve the settleability of filamentous bulking sludge quickly. And sludge volume index (SVI) accordingly declined from 170 ml·g^-1 to 30 ml·g^-1. Extracellular polymeric substances (EPS) and soluble microbial products (SMP) could transform into each other and became the source of carbon and energy for hungry bacteria to guarantee cell maintenance in a long term starvation environment.

Nitrobenzene was selected as a model contaminant to examine the effects of initial concentration of nitrobenzene, dosage of iron, rate of iron/carbon and pH (pH<3.0) on removal efficiency of nitrobenzene by iron-carbon micro-electrolysis. The initial concentration of nitrobenzene determined the dosage of iron. The additional activated carbon could compete with degradation substrate on electron accepting, leading to a negative effect on the efficiency of electron usage, and decreased reduction efficiency of iron-carbon micro-electrolysis. Low pH could increase reaction rate of iron-carbon micro-electrolysis, and increasing pH during the reaction had a remarkable effect on formation and distribution of intermediate reduction products, including phenylhydroxylamine and aniline.

The operation performance of fermentative hydrogen production in anaerobic contact reactor (ACR) at different influent COD concentrations was investigated. The ACR could be kept at steady-state with ethanol-type fermentation, as influent chemical oxygen demand (COD) increased from 7000 mg·L^-1 to 11000 mg·L^-1 with constant HRT of 6 h. Specific hydrogen production of the ACR system increased from 2.43 m³·(m³·d)^-1 to 3.51 m³·(m³·d)^-1 as influent COD increased from 7000 mg·L^-1 to 11000 mg·L^-1, while specific hydrogen production of activated sludge peaked at 10.71 mol H₂·(kg VSS·d)^-1 at influent COD of 9000 mg·L^-1. The results of polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) profiles showed that hydrogen-producing ethanol fermentative bacteria were dominant in the ACR. As influent COD concentration increased, Ethanoligenens harbinense YUAN-3 became more abundant, and propionate fermentative bacteria, i.e. Propionicimonas sp. F6 also started to be enriched.

A dilution sampling method was used to collect PM_2.5 before and after COHPACs (compact hybrid particulate collector) generated by a pulverized coal boiler (boiler A) and a circulating fluidized bed boiler (boiler B) with installed capacities of 220 MW and 300 MW, respectively. Particle size distributions (PSDs) of PM_2.5 were analyzed by ELPI; individual microstructures of PM_2.5 were analyzed by SEM (scanning electron microscopy); concentrations of minor elements in PM_2.5 were analyzed by EDX (energy-dispersive X-ray analysis) and concentrations of trace elements in PM_2.5 were analyzed by ICP-OES (inductively coupled plasma optical emission spectroscopy). The distribution characteristics of number and mass concentration of PM_2.5 at the corresponding sampling positions of two boilers were different. Most of the PM_2.5 before and after COHPAC-A (boiler A's) were spherical; most of the PM_2.5 before and after COHPAC-B (boiler B's) were irregular in shape; the PM_2.5 after COHPAC-A were with relatively uneven surface, PM_2.5 microstructures before and after COHPAC-B were similar; mass fraction size distributions of Si, Al, Fe, Ca and Mg in PM_2.5 before and after the two COHPACs were similar; mass fraction size distributions of As, Cd and Se in PM_2.5 before and after the two COHPACs increased with decreasing size; mass fraction size distributions of As and Se in submicron PM_2.5 after COHPAC-A were higher than those before COHPAC-A, but mass fraction size distributions of As and Se in PM_2.5 before and after COHPAC-B were correspondingly nearly the same.

Oxidants of nitric acid and acidic potassium dichromate were used to modify anode carbon cloths. Modification was completed by first putting the carbon cloth into nitric acid or acidic potassium dichromate at a given temperature, soaking for 30 min and then rinsing with de-ionized water until no variation in pH and finally putting into a vacuum dryer, drying for 12 h. Fourier transform infrared spectroscopy measurements indicated that many hydroxyls and carboxyls were attached on the carbon cloth surface after modification. SEM results showed that the surface of carbon cloth became rougher than the unmodified one. In addition, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements demonstrated that both modified anodes had excellent electrochemical properties. Using the modified carbon cloths as microbial fuel cell (MFC) anodes respectively, such MFCs yielded maximum power densities of 291.11 mW·m^-2 and 438.08 mW·m^-2, 21% and 82% higher than that of the MFC with unmodified carbon cloth anode respectively.

For proton exchange membrane fuel cell (PEMFC) power supply system after shutdown, fuel cell open circuit high voltage is considered to be an important factor causing low battery performance and shortened life. This is mainly because after shutdown of PEMFC power system, fuel cell is in an open state. Residual hydrogen on the anode side reacts with air on the cathode side and the battery is at open circuit high voltage which is maintained for a long time. It is easy to cause oxidation of catalyst carbon carrier and shedding of distributed platinum (Pt) particles, and consequently decayed fuel cell performance and shortened life expectancy. Aiming at minimizing the time of shutdown open circuit high voltage and accelerating consumption of residual hydrogen on the anode, a shutdown strategy of PEMFC power system was proposed, and the influence of direct shutdown and shutdown strategy on PEMFC output characteristics was studied through experiments. The effectiveness of the shutdown strategy was verified, and references guidance was provided for protective shutdown strategy of PEMFC power system.

Non-metal particles of waste printed circuit boards (NPWPCB) were modified with 3-aminopropyltriethoxysilane (KH-550) by coating in a spout-fluid bed with draft tube. To obtain the range of operating parameters for the modification, the effects of KH-550 solution (20%(vol)) volume, spray rate, atomizing gas velocity, bed temperature, and spouting gas velocity on modification were evaluated. The modified NPWPCB were used as filler to fabricate PP/NPWPCB composites by extrusion and injection molding. The variations of the surface functional groups and the cross-section morphology were characterized by infrared spectroscopy and scanning electron microscopy. Modified NPWPCB improved the interface bonding between NPWPCB and PP, which enhanced the mechanical properties of PP/NPWPCB composites. At KH-550 solution (20%(vol)) volume of 75 ml, spray rate of 3.2 cm·s^-1, atomizing gas velocity of 58.98 m·s^-1, bed temperature of 80℃, and spouting gas velocity of 29.49 m·s^-1, flexural strength, tensile strength, and impact strength of the composites increased by 15.07%, 17.52% and 16.32%, respectively.

Carbon nanotubes/epoxy resin (EP) cellucotton composite was prepared on a large scale using EP as the precursor sol, aluminum plates covered with carbon nanotubes as substrate, by a simple and convenient electrospinning and collaborative pulling technology. The morphology, structure and composition of the obtained samples were investigated with scanning electron microscopy, thermogravimetric analyzer, mercury injection test and Raman spectroscopy. Carbon nanotubes were partly wrapped and distributed evenly on the surface of the EP fibers, and the composite structures had high specific surface area and porosity. The contact angle of the carbon nanotube/EP composite structure was 114.1° for water, and 66.8° for vegetable oil. The as-made carbon nanotubes/EP composites showed superior adsorption capacity for vegetable oil, which was better than polypropylene fiber, and could adsorb more than 10 times of oil in terms of their own mass.

Electrode material of MnO₂ hollow nanosphere was synthesized via a simple hydrothermal process in the presence of Ce ion. Ce ion played a crucial role in controlling the morphology and crystalline structure of MnO₂. The hollow nanosphere consisted of nanorods, and Brunauer-Emmet-Teller (BET) specific surface area of the hollow nanosphere was 315.2 m²·g^-1. Electrochemical behavior of MnO₂ electrode material was measured by cyclic voltammetry and galvanostatic charge-discharge. Better electrochemical properties of MnO₂ electrode could be obtained when mole ratio of Ce to Mn was 0.2, and specific capacitance of as-prepared MnO₂ electrode was 178.6 F·g^-1, 2.6 times higher than MnO₂ electrode without Ce ions. Moreover, MnO₂ electrode exhibited remarkable cyclability, and specific capacitance retained 90.5% even after 1000 cycles. Ce ion was favorable for forming a hollow structure, and improved specific capacitance of MnO₂ electrode.

One of the greatest challenges in the application of organic phase change materials (PCMs) is to increase their thermal conductivity while maintaining high phase change enthalpy. To prepare nano-organic composite PCMs for air-conditioning cool storage, nanomaterials with high thermal conductivity, including multi-walled carbon nano-tubes (MWNTs), Al₂O₃ and Fe₂O₃, were respectively added into the organic composite PCMs of caprylic acid/myristyl alcohol (with mass ratio of 73.7 to 26.3), developed previously in this study. The thermal properties of nano-organic composite PCMs were analyzed by measuring their thermal conductivity coefficient. The kinds and concentrations of nano-materials are key influencing factors. The experiments showed that heat conductivities increased obviously when mass fractions of MWNTs, Al₂O₃ and Fe₂O₃ nanomaterials were less than 0.3%, 0.4% and 0.8%, respectively. Compared with the original PCMs, heat conductivity increased by 26.3% when mass fraction of MWNTs was 0.3%; heat conductivity increased by 13.1% when mass fraction of Al₂O₃ was 0.4%; the heat conductivity increased by 32.1% when mass fraction of Fe₂O₃ was 0.8%. The thermal conductivity enhancement effects were in the order of Fe₂O₃, MWNTs and Al₂O₃ at a specific mass fraction (e.g., 0.7%) of nanomaterials. The nano-organic composite PCMs prepared had a limited influence on phase change temperature and phase change enthalpy of the original PCMs, fluctuation of phase change temperature was less than 0.4℃, and the greatest fluctuation range of phase change enthalpy was 1.4%.

In order to improve salt resistance, temperature tolerance and stability of the acrylamide-based copolymer, the hydrophobic associating copolymer (DTHAP) of acrylamide (AM) with acrylic acid (AA) and a double-tailed hydrophobic monomer (N-phenethyl-N-tetradecylmethacrylamide, PETMAM) was synthesized by photo-initiated radical polymerization. By measuring apparent viscosity of the hydrophobic associating polymer, the effects of amounts of acrylic acid, salt, surfactant (SDS) and content of the double-tailed hydrophobic monomer on the properties of the copolymer were investigated. The critical associating behavior of the copolymer could be affected by changing the amounts of surfactant and acrylic acid. Then, the amount of surfactant could be reduced by adding NaCl to the solution in the micellar polymerization process. Finally, even at low concentration [0.35%—0.45%(mol)] of hydropobic monomer, the copolymer could exhibit obvious thickness. For the hydrophobic associating copolymer synthesized, its critical association mass concentration was about 0.75 g·L^-1 and its viscosity was 141.5 mPa·s at the concentration of 1 g·L^-1. After ageing for 90 d at 80℃, the apparent viscosity of 2 g·L^-1 DTHAP in 120 g·L^-1 NaCl solution was 47.6 mPa·s. Even in 120 g·L^-1 NaCl and 0.4 g·L^-1 CaCl₂ solution, the viscosity of the copolymer solution could be kept at around 45.9 mPa·s. The copolymer was characterized with FTIR and SEM, and its structure was confirmed.

Intumescent flame retardant thermoplastic starch (TPS) as char forming agent, ammonium polyphosphate (APP) and expandable graphite (EG) were used to prepare thermoplastic starch/ethylene-vinyl acetate copolymer (TPS/EVA) foam composites by melt mixing, mill plasticizing and sulfuration foaming. The effect of thermoplastic starch content on the flame retardant, mechanical and processing properties of TPS/EVA foam composites was investigated. With the introduction of char forming agent TPS, flame retardancy and charring of TPS/EVA foam composites could be significantly improved. With increasing TPS content, tensile strength, elongation at break and tearing strength of TPS/EVA foam composites showed a downward trend after firstly rising and specific gravity showed a modest rise. The TPS/EVA foam composites had best comprehensive properties at the loading of 6%TPS, i.e. LOI 26.5%, UL-94 V-0 rating, tensile strength, elongation at break, tearing strength and specific gravity 2.395 MPa, 177.48%, 10.59 N·mm^-1, 0.21452, respectively.

Polyacrylonitrile (PAN) precursor fiber and pre-oxidized fiber were tested with Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) to investigate the accuracy of pre-oxidation extent which was measured by testing. On the basis of the study on influence factors during the FTIR test, FTIR spectra and relative cyclization index (RCI) were analyzed. Furthermore, aromatization index (AI) was also studied via comparing the thermal properties of precursor fiber and pre-oxidized fiber. The pre-oxidation extent of pre-oxidized fiber could be qualitatively evaluated by FTIR and DSC, while RCI by quantitative calculation was not comparable and AI was higher than the true value.

PASP modified liposomes (PLPs) were prepared by using negatively charged PASP chains linked to the head of positively charged phospholipid via electrostatic adsorption. A "one-step" method was developed to form and modify the liposomes. Single factor experiments were conducted to prepare high pH sensitive PLPs. The optimal formula in preparing PLPs was 2.5%(mass) PASP solution with pH8.5. TEM results showed that PASP modified liposomes had a larger particle size and their surface with higher electro-negativity. PASP modified liposomes are a kind of relatively stable emulsion system.