Effects Of Key Factors Research Articles

Cinnamon bark as low-cost and eco-friendly adsorbent for the removal of indigo carmine and malachite green dyestuffs

ABSTRACT This study aims to determine the adsorption potential of the cinnamon bark (CB), which is an agricultural waste, as an adsorbent for the removal of dyestuffs such as indigo carmine (IC) and malachite green (MG) from aqueous solution. Additionally, it includes the application of ‘univariate and multivariate techniques’ for determining the effects of key factors on adsorption process. The results obtained from experiments performed according to Central Composite Design (CCD) were evaluated with the Response Surface Methodology (RSM) approach. In optimum conditions (pH = 2, m = 1.80 g, t = 90 min, Co = 85 mg/L for IC and pH = 7, m = 0.45 g, Co = 30 mg/L for MG), the removal efficiencies of IC and MG adsorption onto CB were found as 84% ± 2 and 98.2% ± 0.2, with standard deviations (N = 3), respectively. The concordance of experimental data with pseudo-second-order kinetic model demonstrated that the adsorption was chemically controlled and an endothermic process that ongoing with increasing randomness on the adsorbent/adsorbate interface for both dyestuff removal. However, IC adsorption was non-spontaneous; MG adsorption was spontaneous. Because the equilibrium data were well explained to by Temkin isotherm model, the nature of adsorption was defined by the assumption that the binding energies of adsorption had a uniform distribution.

Theoretical and Experimental Studies of Chip Position Drift in Motional Chip Placement Process

Accuracy and efficiency of chip placement process play a critical role in electronic packaging technology since it can determine the success ratio and throughput of chip packaging system. In this paper, a new motional chip placement process is proposed to improve the process efficiency, where the chip is placed onto the substrate with a contact velocity. However, the moving chip is also more likely to produce position drift on the anisotropic conductive adhesive, which will result in low accuracy of chip placement process. In view of this, a three-layer model considering the effect of the chip contact velocity is presented to address the dynamic behavior of chip placement process, where the geometrical dimensions and material properties of this model are included. In addition, the mechanism of motional chip placement process is uncovered, and the effects of key factors, including chip length, adhesive viscosity, and chip contact velocity on chip motion, are analyzed. The results show that the moving chip is helpful for the efficiency of chip placement process, but it also may cause low accuracy of chip placement process. Finally, in order to select appropriate key factors, the technical criteria are discussed, and the process window for reliable motional chip placement is established and verified by experiments.

Optimized charging of lithium-ion battery for electric vehicles: Adaptive multistage constant current–constant voltage charging strategy

This paper proposes an adaptive multistage constant current–constant voltage (MCCCV) strategy for charging electric vehicles in different situations. First, a high-fidelity thermoelectric-aging coupling model based on a resistor–capacitor pair electrical model, a thermal network model, and a semiempirical aging model is constructed. Second, an adaptive MCCCV charging strategy involving optimization of the charging current using particle swarm optimization is developed. It can satisfy the preference of users for reducing the charging time or the battery degradation. Finally, three charging strategies based on the Pareto boundary curve of the battery charging time–state of health are developed: a fast-charging strategy for motorway driving, a minimum-aging charging strategy for family use, and a balanced charging strategy for daily use. Additionally, according to the Pareto boundary, the effects of key factors on the optimization of the charging strategy are analyzed and compared. The results show that the balanced charging strategy is 3.60% better than the 0.5C constant current–constant voltage (CCCV) charging strategy recommended by the battery manufacturer with regard to aging loss. Moreover, the charging time is reduced by 37%. Compared with the traditional CCCV charging strategy, the proposed adaptive MCCCV charging strategy has good application prospects with regard to both the charging time and the battery degradation.

A numerical method for estimating the elastic modulus of recycled concrete

This paper aims at presenting a numerical method for estimating the elastic modulus of recycled concrete with crushed aggregates. In the method, polygonal aggregates following a given sieve curve are generated, and placed into a square simulation element with the aid of the periodic boundary condition and the overlap criterion of two polygonal aggregates. The mesostructure of recycled concrete is reconstructed by embedding an old interfacial transition zone (ITZ) layer inside each recycled aggregate and by coating all the aggregates with a new ITZ layer. The square simulation element is discretized into a regular grid and a representative point is selected from each sub-element. The iterative method is combined with the fast Fourier transform to evaluate the elastic modulus of recycled concrete. After the validity of the numerical method is verified with experimental results, a sensitivity analysis is conducted to evaluate the effects of key factors on the elastic modulus of recycled concrete. Numerical results show that the elastic modulus of recycled concrete increases with the increase of the total aggregate content and the elastic moduli of old and new ITZ but decreases with increasing the replacement ratio of recycled aggregate and the thicknesses of old and new ITZ. It is also shown that, for a replacement ratio of recycled aggregate smaller than 0.3, the elastic modulus of recycled concrete is reduced by no more than 10%.

Effects of key factors on the heat insulation performance of a hollow block ventilated wall

A hollow block ventilated wall can be cooled down in the summer and warmed in the winter by utilizing the air that flows through cavities. The heat transferred between the outdoor and indoor environments can also be removed. However, neither simulations nor experimental studies on the hollow block ventilated wall have been complete, and factors that affect the thermal insulation performance of hollow block ventilated walls need to be identified. In this paper, the frequency-domain finite-difference method and the Number of Transfer Units method are adopted to build the coupled three-dimensional heat transfer model for investigating the temperature distribution on wall surfaces and the exhaust airflow. Experiments are carried out to validate the three-dimensional model, and comparisons prove that the model has considerable accuracy. In addition, both the numerical and experimental studies show that the hollow block ventilated wall can significantly reduce the heat transferred from outdoor environments to indoor rooms through ventilation in the summer. The effects of influential factors, including the airflow velocity, the inlet temperature of the airflow and the cavity size, on the thermal insulation performance of the hollow block ventilated wall are investigated based on the heat transfer model. Results show that the temperature of the inner surface of the hollow block ventilated wall at four orientations is reduced and ranges from 24.8 to 27.0 °C during a typical summer day. The heat flux through the inner surface is reduced by 55.08%, 55.07%, 56.03% and 55.19% respectively for the east, west, south, and north hollow block ventilated walls, indicating the energy saving potential of hollow block ventilated walls. The most critical factor is the cavity size. When the cavity dimension is constant, the influence of the airflow velocity on thermal insulation is much larger compared to the airflow temperature, and the suggested airflow rate is 1.3 m/s. Results show that a higher airflow rate, higher inlet airflow temperature, and larger cavity size, enable the hollow block ventilated wall to achieve better thermal insulation performance.

Numerical investigation on heat extraction performance of a CO2 enhanced geothermal system with multilateral wells

A CO2 enhanced geothermal system (EGS) with multilateral wells is proposed to exploit hot dry rock (HDR) in this paper. For this EGS, several upper injection and lower production multilateral wells are sidetracked from one main wellbore in HDR. CO2 is injected from the injection multilateral wells into the reservoir and then extracts heat. Subsequently, high temperature CO2 is produced from production multilateral wells and returns to the surface through the insulated tubing in the main wellbore. In this study, a 3D fluid flow and heat transfer model for this CO2-EGS is established. The effects of key factors on the heat extraction performance of this CO2-EGS are studied. The performances of double-well and multilateral-well CO2-EGS are compared. The results indicate that multilateral-well CO2-EGS has a greater heat extraction performance than conventional double-well CO2-EGS. The lower production pressure, more multilateral wells and longer multilateral wells can improve CO2-EGS performance, while the lateral-well diameter has negligible effects on CO2-EGS performance. The injection mass flow rate and well spacing should be optimized to obtain a stable output thermal power and long enough service-time. This work offers good guidance for the optimization design of CO2-EGS with multilateral wells.

Numerical analysis of heat extraction performance of a deep coaxial borehole heat exchanger geothermal system

The coaxial borehole heat exchanger (CBHE) can effectively develop deep geothermal resources with larger heat exchange area than traditional U-tube BHE. However, few studies focus on its parameters optimization and temperature field dynamic response. Hence, an unsteady-state heat transfer model is established for a deep CBHE. The finite difference method is adopted to solve the model, and the model is validated with experiment data. The effects of key factors on the CBHE performance are comprehensively analyzed. Simulation results depict that the outlet temperature decreases greatly at the initial stage, and then remains relatively stable. There is a critical value for flow rate to obtain higher thermal power with appropriate pressure drop. The insulated pipe can significantly reduce heat dissipation of working fluid in central pipe. There is an optimal insulation length in terms of heat insulation effect and costs. The thermal conductivity of cement sheath has remarkable influence on the thermal process and partial cementing with high thermal conductivity cement is favorable. The temperature field analysis shows that the impact scope is limited, and the temperature in the reservoir before the next heating period would almost recover its original condition, verifying the sustainability of CBHE system.

Study on voltage clamping and self-humidification effects of pem fuel cell system with dual recirculation based on orthogonal test method

Durability and reliability are still major challenges of vehicular polymer electrolyte membrane fuel cell (PEMFC) systems. With exhaust gas recirculation on both the anode and cathode sides, two important functions can be achieved: the voltage clamping in low current density, and the self-humidification without any external humidifiers. The former restrains catalyst decay in small load working conditions, and the latter is beneficial for improving the cold-start ability. In this study, dynamic performances and stable characteristics of a fuel cell system with dual exhaust gas recirculation are firstly experimentally studied using an orthogonal test method. System parameters, including humidification temperature of cathode external humidifier, fresh air stoichiometric ratio (SR), current density, cathode and anode recirculation pump speeds, are regarded as key factors in the experiments based on the testing conditions of the test-bench. Two four-factor and three-level orthogonal tables are designed, and the effects of key factors on system performance indices (average cell voltage, relative humidity (RH) at cathode inlet, high frequency resistance (HFR), oxygen concentrations at cathode inlet and outlet, and the concentration difference between these two positions) are investigated. Results show that: (1) with the cathode recirculation, the cell voltage can be reduced in low current densities by coordinately adjusting the recycled gas flow and reducing fresh air SR; (2) with the dual recirculation, the fuel cell membrane can be well hydrated, and system performance only shows 3% reduction compared with a system with an external humidifier; (3) the difference between the oxygen molar concentration at the inlet and outlet of cathode gas channels becomes small using dual recirculation.

System Dynamics Analysis of Evolutionary Game Strategies between the Government and Investors Based on New Energy Power Construction Public-Private-Partnership (PPP) Project

The public-private-partnership (PPP) is a new mode for the government and social capital to jointly invest in public infrastructure projects. In particular, PPP projects for new energy power construction have been strongly supported in some countries in recent years, because it can not only reduce financial pressure on the government, but also promote the development of new energy. Current scholars study the economic benefits of PPP projects for new energy power construction from a macro perspective, and they rarely study behavioral strategies of the government and social capital as a game process of project construction from a micro perspective. This paper will fill this gap. This study firstly built an evolutionary game model of the government and investors based on new energy power construction PPP projects. Secondly, taking China’s typical new energy power construction PPP project–waste incineration power generation as an example, the system dynamics (SD) model was proposed to simulate the evolutionary process of game players’ behavioral strategies. Finally, the effects of key factors in the construction of PPP project on the strategies’ stability were studied. The results show that: (1) there is no evolutionarily stable strategy (ESS) in the game system between the government and investors, and system evolution is characterized by periodic behavior. (2) When the government implements dynamic bounty measures, the system evolution process is still a closed loop with periodic motion. However, when the government implements dynamic punishment measures, there is a stable ESS in the hybrid strategy of the game system. (3) The government can increase unit fines when making dynamic strategic adjustments, which will not only promote the active cooperation of investors, but also reduce the probability of government supervision, thereby reducing costs.

Real-Time Sensing of TET2-Mediated DNA Demethylation In Vitro by Metal-Organic Framework-Based Oxygen Sensor for Mechanism Analysis and Stem-Cell Behavior Prediction.

Active DNA demethylation, mediated by O2-dependent ten-eleventranslocation (TET) enzymes, has essential roles in regulating gene expression. TET kinetics assay is vital for revealing mechanisms of demethylation process. Here, by a metal-organic framework (MOF)-based optical O2 sensor, we present the first demonstration on real-time TET2 kinetics assay in vitro. A series of luminescent Cu(I) dialkyl-1,2,4-triazolate MOFs were synthesized, which were noble-metal-free and able to intuitively response to dissolved O2 in a wide range from cellular hypoxia (≤15 μM) to ambient condition (∼257 μM). By further immobilization of the MOFs onto transparent silicon rubber (MOF@SR) to construct O2 film sensors, and real-time monitoring of O2 consumption on MOF@SR over the reaction time, the complete TET2-mediated 5-methylcytosine (5mC) oxidation process were achieved. The method overcomes the limitations of the current off-line methods by considerably shortening the analytical time from 0.5-18 h to 10 min, and remarkably reducing the relative standard deviation from 10%-68% to 0.68%-4.2%. As a result, the Michaelis-Menten constant ( Km) values of TET2 for 5mC and O2 in ascorbic acid-free (AA-) condition were precisely evaluated to be 24 ± 1 and 43.8 ± 0.3 μM, respectively. By comparative study on AA-containing (AA+) conditions, and further establishing kinetics models, the stem-cell behavior of TETs was successfully predicted, and the effects of key factors (AA, O2, Fe2+) on TETs were revealed, which were fully verified in mouse embryonic stem (mES) cells. The method is promising in wide application in kinetics analysis and cell behavior prediction of other important O2-related enzymes.

Microwave-assisted aqueous two-phase extraction of alkaloids from Radix Sophorae Tonkinensis with an ethanol/Na2HPO4 system: Process optimization, composition identification and quantification analysis

A rapid method for simultaneous extraction and separation of multiple alkaloids from Radix Sophorae Tonkinensis (RST) was developed by microwave-assisted aqueous two-phase extraction (MAATPE) using the aqueous two-phase extraction system (ATPS) of ethanol/Na2HPO4 as the extraction solvent. The effects of key factors on extraction yield were investigated by utilizing single-factor experiment coupled to response surface methodology (RSM). The regression model by RSM was significant (p < 0.0001) and adequate for prediction of process efficacy, the optimized conditions were successfully validated by the parallel experiments with the yield very close to the predicted value. The optimum conditions were summarized as follows: the phase ratio of 2.60 for the ATPS, the particle size of 100 mesh, the liquid-to-material ratio of 75:1, the extraction temperature of 90 °C and the extraction time of 5 min, respectively. In MAATPE process, alkaloids were extracted preferentially from RST in the top phase with a higher yield and shorter extraction time than those of heating reflux extraction (HRE) and ultrasonic-assisted extraction (UAE). Nine alkaloids extracted were identified and quantified by high-resolution ultra-performance liquid chromatography-quadrupole-orbitrap mass spectrometry (UPLC-Q-Orbitrap/MS) and HPLC with UV detection. The contents of matrine, sophocarpine, oxymatrin, sophoranol, oxysophocarpine, 5α-hydroxysophocarpine, sophoridine, cytisine and N-methylcytisine in RST were quantified in range of 0.493–10.284 mg/g with recoveries of 90.26–106.3% and RSD’s of 0.8–2.1%, respectively. Moreover, the MAATPE mechanism was explored using the different extraction systems in combination of scanning electron microscopy (SEM) morphological studies. Significant differences in extraction yield and cell rupture exhibited that the addition of the salt in the ethanol-water mixture not only improved the thermal and demixing effects, but also accelerated the mass transfer and biphasic extraction processes. MAATPE integrated the advantages of microwave-assisted extraction (MAE) and aqueous two-phase extraction (ATPE) was proved as a green, efficient and promising alternative to extraction of alkaloids from RST.

Experimental study on reduction of NO by CH 4 over La 0.8 Sr 0.2 MnO 3 /α-Al 2 O 3 in excess of O 2

Abstract Selective catalytic reduction of NO is necessary for the environment but the present adopted NH3-SCR has its weaknesses. This paper proposes CH4-SCR of NO with perovskite catalyst (La0.8Sr0.2MnO3/α-Al2O3) and experiments were done to study the effect of key factors (resident time, temperature and the initial O2 concentration). XRD patterns and SEM image show that La0.8Sr0.2MnO3 is a catalyst with perovskite structure and this kind of structure has been proved to be efficient in SCR. Experiments show that CH4 can convert NO efficiently in association with catalyst La0.8Sr0.2MnO3/α-Al2O3 and the max NO conversion ratio is over 90%. The longer the resident time is, the higher the conversion of NO is. The conversion of NO increased with the increase of temperature when the initial concentration of O2 ranged from 0% to 3% and moderate O2 at high temperatures can promote the reduction of NO by filling oxygen vacancies in lattice and taking part in the reactions. The new catalyst La0.8Sr0.2MnO3/α-Al2O3 could work efficiently in the widest range of oxygen concentration at 800 °C and it reached 90% with the oxygen concentration ranging from 4% to 6%. This research will provide further data to improve the process of SCR in the power plant.

Fermentative hydrogen production from sewage sludge

ABSTRACTHydrogen production from organic wastes by dark fermentation is promising. Among a variety of organic wastes, sewage sludge has drawn extensive attention due to its large amount, high organic content, and stable source. This paper reviewed the characterization of sludge and the principles and potential of sludge hydrogen fermentation. Poor hydrolysis and low C/N ratio of sludge were two main limitations for sludge hydrogen fermentation. To improve hydrogen production, some pretreatment methods (heat, ultrasound, microwave, alkaline, acid, oxidation, enzyme, and bacteria) and the addition of cofermentation substrates have been applied for enhancing the hydrogen production from sludge fermentation. The effect of key factors (temperature, pH, retention time and organic loading rate (OLR), agitation intensity, nutrients, inhibitors, and inoculum) on hydrogen production and process stability was introduced and discussed. Furthermore, the kinetic models were briefly discussed. After sludge hydrogen fermentation, some end products, including acetate, propionate, butyrate, and ethanol, could be used for deducing the fermentation type and applied as substrates for the second-stage process (e.g., anaerobic digestion and photofermentation) for further energy recovery. The development of these two-stage processes was illustrated. Concluding remarks and perspectives for this process were also evaluated.

Convective heat transfer in a porous-medium micro-annulus with effects of the boundary slip and the heat-flux asymmetry: An exact solution

Flow and heat transfer in a micro-annulus with the porous material is analytically investigated using local thermal equilibrium (LTE) and local thermal non-equilibrium (LTNE) models with effects of flow/thermal slips and asymmetric heat fluxes. Analytical solutions for velocity and temperatures are obtained. Effects of key factors on convective heat transfer are examined. An increase in the Knudsen number and the inverse of a modified Darcy number can homogenize the velocity. When heat flux (HF) ratio is –R2, the temperatures of solid and fluid show linear profiles. LTNE model must be considered for small duct scale, lower effective thermal conductivity ratio or poor local convective heat transfer between solid and fluid phases. A limit exists for heat transfer enhancement by homogenizing the flow field. Critical HF ratios corresponding to the asymptotic line are verified. The opposite effects of flow slip and thermal slip on heat transfer lead to the maximum heat transfer. This analytical solution predicts the thermal performance of porous medium micro-annulus in wide ranges of radius ratio, Knudsen number, and HF ratio.

An Overview of New Progresses in Understanding Pipeline Corrosion

An approach to achieving the ambitious goal of cost effectively extending the safe operation life of energy pipeline to 100 years is the application of health monitoring and life prediction tools that are able to provide both long-term remnant pipeline life prediction and in-situ pipeline condition monitoring. A critical step is the enhancement of technological capabilities that are required for understanding and quantifying the effects of key factors influencing buried steel pipeline corrosion and environmentally assisted materials degradation, and the development of condition monitoring technologies that are able to provide in-situ monitoring and site-specific warning of pipeline damage. This paper provides an overview of our current research aimed at developing new sensors and electrochemical cells for monitoring, categorising and quantifying the level and nature of external pipeline and coating damages under the combined effects of various inter-related variables and processes such as localised corrosion, coating cracking and disbondment, cathodic shielding, transit loss of cathodic protection.

Factors Influencing the Long-Term Properties of Fly Ash-Based Geopolymer Mortar

Abstract The primary goal of the paper was to study the effects of key factors on the long-term mechanical properties of fly ash-based geopolymer. The factors considered consisted of curing time, humidity, temperature, admixture, and water coefficient. In the study, the geopolymer paste and mortar specimens were prepared and cured at four different environmental conditions: (1) ∼24°C and approximately 45 % RH; (2) 95°C and 100 %R.H; (3) 80°C and 25 %RH; and (4) ∼24°C and 90 %R.H. The compressive and flexural strength tests were performed for the mortar specimens at the ages of 7, 28, 120, 360, 540, and 720 days. X-ray diffraction (XRD), X-ray fluorescence (XRF), and nuclear magnetic resonance spectroscopy (23Na, 27Al, 29Si, MAS NMR) tests were performed for the paste specimens at the ages of 7, 28, 120, 360, 540, and 720 days. Selected specimens were also examined under scanning electron microscope (SEM). The results indicated that water evaporation from specimens was a major cause of the strength development of the geopolymer. In addition to SiO4−4 anions in alkali activator, which accelerated the geopolymerization, the Na+, Ca2+, and Mg2+ ions in the system also played an important role in bridging -Si-O-Si-O-Al- chain, thus improving strength development of the geopolymer. The crystallization occurred only in the hydrothermal environment, and it had little influence on the strength development of the low calcium fly ash-based geopolymer mortar as a very small amount of crystalline phase was formed.

Deep dry etching of fused silica using C4F8/Ar inductively coupled plasmas

This paper reports the etching process of fused silica by inductively coupled plasmas (ICP) for through glass via (TGV) applications. Mixed C4F8 and Ar were used as etching gases in present experiments. The effects of key factors, including etching gases, chamber pressure and substrate temperatures, on etch rate and via profile were studied. Results showed that a high etch rate of about 0.75 μm/min with smooth and vertical sidewall of TGVs can be obtained. Compared to Ar flux and chamber pressure, the effect of C4F8 flux on etch rate is more remarkable. Vertical vias (>89°) can be achieved by increasing the substrate temperature and decreasing the mixing ratio of C4F8 and Ar. Besides, micro-pillars at the bottom of via were observed when the substrate temperature was set at 0 °C. As the substrate temperature reached to 80 °C, micro-pillars were removed clearly. Optimized results indicate that the ICP etching is an effective method for fabricating TGV.

Orthogonal test design for optimising the culture medium for in vitro pollen germination of feijoa (Acca sellowiana cv. Unique)

ABSTRACTFeijoa suffers from high rates of flower and fruit abortion, and widely varying fruit characteristics, which are directly related to pollination problems. However, efficient pollination mostly depends on pollen vigour. Thus, methods to improve pollen vigour have become an important focus for both breeders and growers. An orthogonal design method (L9[3]4) was used to compare the effectiveness of key factors (e.g. concentrations of sucrose, H3BO3, CaCl2 and GA3) to determine pollen vigour, and to optimise the culture medium for in vitro pollen germination. The four factors that influenced pollen germination in order of significance are as follows: GA3 > CaCl2 > H3BO3 > sucrose. These variables influenced pollen tube growth in the following order: CaCl2 > H3BO3 > sucrose > GA3. The optimal culture medium for promoting pollen vigour was 10% sucrose, 1.95 × 10–3 mol/L H3BO3, 4 × 10–4 mol/L CaCl2 and 80 mg/L GA3.

Effect of key factors on cold orbital forging of a spur bevel gear

Cold orbital forging is an advanced spur bevel gear forming technology. Generally, the spur bevel gear in the cold orbital forging process is formed by two steps: the preforming step and the final step. Due to the great importance of the final step to gear forming and its complication with interactive factors, this work aims at examining the influence of key factors on the final step in cold orbital forging of a spur bevel gear. Using the finite element (FE) method and control variate method, the influence rules of four key factors, rotation velocity of the upper tool, n, feeding velocity of the lower tool, v, tilted angle of the upper tool, γ, friction factor between the tools and the billet, m, on the geometry and the deformation inhomogeneity of the cold orbital forged gear are thoroughly clarified. The research results show that the flash becomes more homogeneous with increasing v, increasing m, decreasing n or decreasing γ. And the deformation of the gear becomes more homogeneous with increasing v, decreasing n or decreasing γ. Finally, a corresponding experiment is conducted, which verifies the accuracy of FE simulation conclusions.

Research on Adsorbent Using Modified Fly Ash for Campus Domestic Sewage Treatment

As a kind of extensive sources and low cost industrial waste, fly ash has many features, such as porosity, large surface area, adsorption capacity, chemical activity and weakly alkaline, which seem a wide prospect of application in wastewater treatment. This study proposed the acid modification test on fly ash. The effect of key factors including the particle size, pH, the dosage of fly ash, adsorption time and dosage of the modifier on domestic sewage removal efficiencies were evaluated. The optimum conditions and the corresponding removal efficiency were determined. The results show that the removal efficiency is increased firstly and steady subsequently with the increase of fly ash dosage, increased firstly and decreased subsequently with the increase of adsorption time, and increased firstly and decreased subsequently with the increase of pH value. The removal efficiency can up to 95.19% when 0.7 g fly ash added in 200 mL wastewater when the pH value was adjusted to 5 at the adsorption time of 20 min. And the best particle size of fly ash is 200 meshes, when used 2mol/L hydrochloride as modifier and soaked fly ash for 2h, and the ratio of hydrochloride and fly ash is 1mL / g, the effect is best. It also finds obviously that fly ash can have a better effect on removal efficiency than raw fly ash.