Abstract:This article proposes a new idea for back-calculation of the subgrade modulus considering shallow bedrock and the viscoelastic characteristics. For the subgrade model, displacement boundary conditions and the Kelvin model are adopted to describe the depth of the shallow bedrock and the viscoelasticity, respectively. The portable falling weight deflectometer (PFWD) field test is simulated by ABAQUS general finite element (FE) software, and the optimal value of the modulus is iterated by a multi population genetic algorithm (MPGA). Based on the new method, back-calculation results from FE simulation tests show that the modulus average error of the forward model considering shallow bedrock is 7.0%, while that of the forward model considering half space is as high as 16.2%, indicating that negletct of the shallow bedrock in the forward model of the back-calculation program may cause a significant error in the inversion modulus, but its influence decreases with the increase of the depth of the shallow bedrock, and the depth limit is 3 m. Similarly, for the FE model considering viscoelasticity, the maximum error for neglect of this attribute in the forward model reaches 27.9%, compared with the error of only 7.4% when considering viscoelasticity in the forward model. Due to the difficulty exploring the depth of shallow bedrock, examinations are only conducted from the theoretical aspect.

Abstract:In deep underground mining, rockburst is taken into account as an uncertainty risk with many adverse effects (i.e., human, equipment, tunnel/underground mine face and extraction periods). Due to its uncertainty characteristics, accurate prediction and classification of rockburst susceptibility are challenging, and previous results are limited. Therefore, this study proposed a robust hybrid computational model based on gene expression programming (GEP) and particle swarm optimization (PSO), called GEP-PSO, to predict and classify rockburst potential in deep openings with improved accuracy. A different number of genes (from 1 to 4) and linking functions (e.g., addition, extraction, multiplication and division) in the GEP model were also evaluated for development of the GEP-PSO models. Geotechnical and constructive factors of 246 rockburst events were collected and used to develop the GEP-PSO models in terms of rockburst classification. Subsequently, a robust technique to handle missing values of the dataset was applied to improve the dataset's attributes. The last step in the data processing stage is the feature selection to determine potential input parameters using a correlation matrix. Finally, 13 hybrid GEP-PSO models were developed with varying accuracies. The findings indicated that the GEP-PSO model with three genes in the structure of GEP and the multiplication linking function provided the highest accuracy (i.e., 80.49%). The obtained results of the best GEP-PSO model were then compared with a variety of previous models developed by previous researchers based on the same dataset. The comparison results also showed that the selected GEP-PSO model results outperform those of previous models. In other words, the accuracy of the proposed GEP-PSO model was improved significantly in terms of prediction and classification of rockburst susceptibility. It can be considered widely applied in deep openings aiming to predict and evaluate the rockburst susceptibility accurately.

Abstract:Fractures significantly influence fluid flow and mass transport in projects of radioactive waste disposal in deep geological formations. This work investigated the mechanism of nuclide migration in fractured rocks by considering fracture roughness based on a unified pipe-network method (UPM). The processes of adsorption and decay were incorporated into the UPM framework to capture the nuclide migration in a rock mass with rough-walled fracture networks. Benchmark tests were attempted against analytical results of the concentration distribution along a single fracture. An equivalent method to approach the hydraulic fracture aperture in fractured rocks by considering fracture roughness was also demonstrated. The influences of the fracture-roughness distribution, the rock matrix adsorption capacity and the transport properties on the process of nuclide migration were investigated. The results show that the breakthrough curve for the nuclide migration moved toward a longer time with increasing fracture roughness. The increased diffusion coefficient and retardation factor in the rock matrix greatly enhanced the matrix retardation effect on nuclide migration. Furthermore, the nuclide featured longer half-life results in a higher relative nuclide concentration of the domain. A hydraulic gradient with a relatively low value greatly impacted the relative concentration's distribution.

Abstract:In order to solve the difficulty and complexity for three-dimensional dynamic uncertainty problem of tunnel surrounding area. Based on the finite element method (FEM), this paper presents an efficient and accurate method for dynamic performance simulation of super long tunnel structure by using 2.5-dimension technique and PML to deal with the boundary truncated by FEM mesh. Since the combination of 2.5-dimension method, finite element method (FEM) and perfectly matched layer (PML) is not common, we derive the equations of the combination of 2.5D technique and FEM, and emphasize its compatibility with 2.5D technique and PML. After a brief introduction of the model, a series of verification examples are provided to prove the accuracy of the model. Finally, parametric studies are carried out to evaluate the influence of tunnel and soil properties on soil vibration. The results show that the proposed 2.5D MEF-PML method can solve the problem that the finite element method can not deal with the infinite domain, and has high accuracy, making it possible to accurately consider the influence of the factors around the tunnel in the dynamic analysis of the tunnel.

Abstract:Energy pile is a type of structure which can not only exchange energy with soil, but also bear the upper loading. In the seasonal frozen soil area, the upper soil layer would be frozen, and the soil in the lower part would not. The thawing settlement, frosting heave and self-deformation of the pile caused by temperature variation are the main problems to be solved for application of energy piles in this area. According to the distribution characteristics of ground temperature in seasonal frozen soil areas, the soil was divided into frozen layer and non-frozen layer, and the model tests were carried out respectively. The pile and soil temperature distribution, pore water pressure of the soil surrounding the pile and pile displacement after multiple temperature cycles in frozen and non-frozen layers were measured. The results show that irreversible settlement of the pile top would occur after multiple cycles of heat extraction in the non-frozen soil area. After 5 cycles of heat extraction, the settlement of the pile top reached 0.95%D (D is the diameter of the pile), while the settlement of the pile would not reach stable state. In the frozen layer, thawing settlement of the pile would occur in the heat injection process, and frosting heave of the pile would occur in the recovery process. The settlement caused by thawing gradually decreased with increase of thermal cycles, and disappeared after the 3rd heat injection cycle. The thawing settlement of the pile after the 1st, 2nd and 3rd heat injection reached 5.9%D, 0.93%D and 0.11%D, respectively. During each cycle, although the rising displacement caused by frosting heave decreased in each following cycle, it still existed after 5 cycles, and the displacement caused by frosting heaving rose is of a ladder shape. The pile heave was produced in the end and reached 3.8%D.

Abstract:Based on enzyme induced calcium carbonate precipitation (EICP) technology, plant urease was used to improve and strengthen desert aeolian sand. In order to find a cheap and simple urease extraction method, potato was used as the raw material, deionized water, glycerol aqueous solution and ethanol aqueous solution were used as extraction solution, and the plant urease in potato was separated and extracted by crushing, refrigeration and high-speed centrifugation, so as to study the influence of different extraction solutions on the extraction effect of urease; The results showed that the best of the three extracts was ethanol solution. When the solid-liquid ratio was 1:6 and the concentration of ethanol solution was 30%, the urease activity value was the highest and the extraction effect was the best. In the improvement experiment of aeolian sand, a hard crust is formed on the surface of the specimen and is of high compressive strength, and the unconfined compressive strength increases gradually with increase of cycles of soaking urease.

Abstract:The evolution pattern and development trend of secondary debris flow in the strong earthquake area were significantly affected by the “post-effect” of the earthquake. The peak discharge had increased several times compared with that before earthquake, and the scale of the debris flow had increased obviously. According to the norms, the new challenge to the targeted design of prevention and control of the gully debris flow in seismic area is being put forward. Therefore, based on the case of debris flow in Wenchuan earthquake, the factorial regression analysis was used to investigate the intrinsic relationship between the basic characteristic parameters and the peak discharge in this paper, and a multivariate prediction model was established. The problem of information superposition caused by the collinearity of the original variables was solved, with goodness of fitting R2=0.94, and the prediction accuracy was improved significantly; at last, the proposed model was used to predict the peak discharge thresholds of 32 debris flows in the study area, and the distribution law of dynamic characteristics and the scale evolution characteristics of debris flow were analyzed in strong earthquake area. Based on results above, the characteristic parameters of “super-large-scale high-level long-distance debris flow” was defined.

Abstract:Initial in-situ stress field is an important basis for design and construction of underground engineering, while it is difficult to accurately measure the initial in-situ stress in engineering practice. In order to accurately obtain distribution law pattem of initial geostress field, the immune algorithm combined with BP neural network (IA-BP algorithm) for inversion of initial in-situ stress field is studied. The optimization of BP neural network by immune algorithm is to encode the connection weights and thresholds of BP neural network as antibodies in the immune algorithm. The hybrid algorithm can not only take advantage of the characteristics of immune algorithm as well as the global optimization quick search for the global optimal solution or near optimal solution, and can also adopt BP algorithm to avoid the near optimal and sub-optimal solutions, oscillation on the local optimization, realizing the aim of fast converge of the global optimal solution. The plane slope model and three-dimensional model were constructed by COMSOL respectively to carry out forward analysis and calculation, and the calculated results were taken as “measured values” to conduct inversion analysis of in-situ stress, but the inversion results of IA-BP algorithm were compared with those of PSO-BP and multiple linear regression algorithms. The results show that the inversion error of IA-BP algorithm is smaller under the two-dimensional (2D) slope model. Under the three-dimensional (3D) model, IA-BP algorithm from the measured values and the inversion of the absolute value of relative error between 0% and 10.64% (3.39% on average), for PSO-BP, it is between 1% and 48.39% with average value of 6.93%, for MLR, it is between 0.55% and 121.95% with average of 21.87%. By comparison, it can be known that the overall inversion results of IA-BP algorithm have the highest accuracy. In both 2D and 3D models, the error of the inversion results is smaller than those using the other two. The application of IA-BP intelligent algorithm to the inversion of in-situ stress field can provide technical support for the construction of underground engineering.

Abstract:In order to understand the rotation phenomenon in the failure process of masonry wall and the influence of rotation deformation on the seismic performance of masonry wall, rotation of ordinary masonry wall, masonry wall with constructional column and reinforced masonry wall are extracted, and the rotation deformation under different specimen designs, stress conditions, reinforcement methods and other factors are summarized The influence of rotational deformation on the seismic performance of masonry wall is discussed. The results show that: rotation is common in the stress process of masonry wall, and even appears the failure phenomenon of rotation deformation control; rotation deformation reduces the bearing capacity and equivalent lateral stiffness of masonry wall, and the wall deformation capacity is improved when rotation failure occurs. At present, the literature of masonry wall seismic test generally lacks description of rotation phenomenon, but it is not without rotation deformation. In the subsequent research work, it is suggested to pay attention to the rotation deformation phenomenon of masonry wall and its impact on seismic performance.

Abstract:In recent years, FRP (Fiber Reinforced Polymer) bars have been used more and more widely in concrete structures instead of steel bars. Unlike the latter, FRP bars have the characteristics of anisotropy, heterogeneity and different surface forms, which lead to the different bond mechanisms between FRP bars and concrete. In order to fully understand the bond behavior, a database of 342 pull-out test specimens was set up. The influence of various factors on the bond behavior was analyzed. The viewpoints that there was no consensus were supplemented and discussed. The effects of high temperature, freeze-thaw cycle and electrolyte solution on the bond behavior of FRP bars and concrete were also analyzed. In addition, the predictive accuracy of the commonly used bond-slip constitutive models were checked. Based on the established test database, a new expression of the rising section of the bond-slip constitutive model was set up.

Abstract:To study the mechanical performance of prefabricated concrete beam-column joints with different connection forms, the cyclic loading test for one monolithic concrete joint and two prefabricated concrete beam-column joints were conducted to evaluate the damage characteristics, beam end's moment-rotation, joint core shear force-beam end's rotation, stiffness degradation and strain of steel plates. The results show that the prefabricated concrete joint with square steel tube experienced flexural damage, and the prefabricated joint with end plates and horizontal connection plates and monolithic joint presented shear damage at the joint core. The bending moment and shear force of prefabricated joints significantly increased, while shear deformation in the core area decreased, stiffness degradation constrained, and the rotation in the beam end significantly enhanced, thus the mechanical performance significantly improved. The joint with square steel tube and orthogonal steel plate had the best mechanical performance, which was much better than that of the monolithic joint. The connection forms in which steel connectors were added to the joint core region, H-steel was set in the beam end, welded or bolted connection were used on site, and post-casting concrete was poured in the connection area could effectively transfer force and improve the mechanical performance.

Abstract:To study the lap splice length of U-shaped rebar loop in precast concrete structure, three fabricated specimens with different lap splice length and one cast-in-place beam-column joint comparison specimen were carried out for low-cycle repeated quasi-static tests. By observing the failure modes of each specimen, the corresponding hysteretic behavior, bearing capacity, deformation capacity, and the stress development process of reinforcement were studied, and then the reasonable lap splice length of U-shaped rebar loop in precast concrete structure was analyzed. The results show, (1) the bearing capacity of fabricated joints is higher than that of cast-in-place joints; (2) the ductility and energy dissipation capacity of specimens with different lap splice length are different; (3) the increase of lap splice length is conducive to the improvement of the bearing capacity, ductility, and energy dissipation capacity of specimens. Finally, based on the test results, the reasonable lap splice length of U-shaped rebar loop is fitted and regressed, and then the suggestions for the optimal design of the joint of the lap splice length of U-shaped rebar loop in precast concrete structure are putting forward.

Abstract:This paper presents an experimental investigation on the load transition mechanism of the joint surface , and the effects of shearing stud and bar-planted placements on structural capacity for the steel-concrete composite strengthening structure with coated steel plate. Six groups of steel-concrete composite specimens with various deployments of shearing stud and bar-planted are carried out. The influences of the arrangement interval of shearing stud and bar-planted on the mechanical behavior and load-bearing capacity are compared; the working and damage behavior of the steel-concrete composite joint surface is studied based on the experimental data and failure modes. Results showed that compared with the steel-enveloped approach with greater rigidity of the reinforced structure, the structure is reinforced by the enveloped steel plate with greater rigidity, and the strength of the joint surface is higher. The grouting-connected pattern of bar-planted and shearing stud cannot satisfy the correspondence deflection requirement of enveloped steel plates and inner-concrete cores due to the stricter strength requirement of the joint surface . Although the changes in number of shearing stud nearly have no effect on the structural stiffness and the ultimate capacity of the enforced components for a certain range, the premature local instability of enveloped steel plates is prevented, by which the plasticity and ductility can be fully utilized.

Abstract:In order to explore the fracture performance of basalt fiber concrete (BFRC), the three-point bending beam method of the Hydraulic Concrete Fracture Test Procedure was used to fabricate concrete specimens with different fiber lengths and dosages with a joint height ratio of 0.4, and the MTS test was used. The machine carried out the loading test on the specimen, obtained the test results of the basalt fiber concrete three-point bending beam, and analyzed the fracture parameters such as P-CMOD curve, initiation toughness, instability toughness and fracture energy, and obtained the following conclusions: After the basalt fiber is added, the fracture performance of the specimen has been improved. The more the fiber content, the longer the fiber length, and the fuller the descending section of the P-CMOD curve; the specimen with a fiber length of 18 mm and a content of 1.5% will start the improvement of fracture toughness and instability fracture toughness is the most obvious; the specimen with a fiber length of 12 mm and a content of 1.5% has the largest fracture energy.

Abstract:Bamboo composite is a kind of engineering composite bamboo with modern processing technology, high strength and quality ratio, environmental protection and beautiful appearance. In order to study the influence of shear-span ratio on the shear capacity of side-loaded bamboo-integrated beams, five groups of three beams in each group with shear-span ratio of 0.75, 1.0, 1.5, 2.0 and 2.5 were designed to carry out four-point bending tests. The deformation characteristics, failure modes and the influence of shear-span ratio of side-loaded bamboo-integrated beams were studied. The influencing factors of shear performance and the calculation method of bearing capacity of bamboo composite beams were studied. The results show that the bamboo composite beams have higher bearing capacity and stiffness, and the shear capacity is related to the ratio of shear span. When the shear span ratio is less than 1.5, interlaminar shear failure occurs, while when the shear span ratio is greater than or equal to 1.5, bending failure occurs. The formulas for calculating the flexural bearing capacity, shear bearing capacity and elastic deformation of bamboo composite beams are put forward, which is in good agreement with the measured values.

Abstract:Solar thermal energy technology is one of the important means of solar energy utilisation, among which tower solar thermal energy technology has advantages such as large-scale energy storage and has good application prospects. As an important unit of a tower solar thermal power plant, the wind safety of the heliostat directly affects the normal operation of the plant. This paper presents a literature review of the key issues in the wind resistance design of heliostats in terms of structural system, wind loads, wind induced response and vibration control, etc. The following conclusions are obtained: Heliostats mainly adopt the structural form of “large size reflector + frame mirror frame + monopole base”; The wind load simulation has problems such as difficulties in analyzing the turbulence in the wake of the heliostat, difficulty in predicting the peak load of the mirror and lack of verification of the measured values; Wind-induced response is strongly influenced by the turbulence intensity of the incoming wind, the working angle of the mirror and the layout of the mirror field, etc. ; Wind vibration control can be achieved by the physical isolation of the wind barrier, adjustment of the mirror structure and the use of vibration damper control. However, further research is needed on the effects of wind disturbance in mirror groups, fluid-structure coupling of incoming wind and mirror structures and micro-vibration control techniques, in order to provide a technical basis for improving the safety of mirror structures against wind.

Abstract:Reinforcement corrosion is the primary cause of the failure of marine concrete structures. Thus, it is necessary to explore the development of corrosion expansion stress and the process of induced concrete cracking, which is beneficial to the service life prediction of reinforced concrete. In the experiments, the reinforcement corrosion in mortar is accelerated by adding salt and using constant potential. The strain in the reinforcement corrosion process is monitored by the strain gauge attached to the stainless steel ring outside the mortar to calculate the corrosion expansion stress. The COMSOL software is used to analyze the development of corrosion expansion stress in concrete and the whole concrete cracking process induced by reinforcement corrosion. The results show that the finite element method and the time-varying radial displacement loading method can be used in simulating and testing the corrosion expansion and cracking process of reinforced concrete respectively, the results of which are basically consistent. Without considering the inhomogeneity of mortar and reinforcement and the filling effect of corrosion products on cracked mortar, the simulation results fail to reflect the fluctuation and the process of release and gradual increase of corrosion expansion stress. In addition, by increasing the mortar strength and decreasing the reinforcement diameter, corrosion expansion and cracking of reinforcement can be effectively delayed.

Abstract:Based on the method of nitric acid accelerated dissolution test, the comparative study on the corrosion resistance durability of natural aggregate concrete (NAC) and recycled aggregate concrete (RAC) prepared using 100% of recycled coarse aggregate (RCA) with different qualities (class I, class Ⅱ and class Ⅲ) is performed. The degradation law and damage mechanism of corrosion resistance of RAC are further revealed from the aspects of macroscopic mechanical property degradation and internal microstructure damage. The results show that the compressive strength of recycled concrete prepared by high-quality aggregate with better physical properties is higher, and there is a good correlation between them. In the corrosion environment, the compressive strength loss rate, mass loss rate and corrosion depth of recycled coarse aggregate concrete gradually increase with the increase of corrosion age, but not strictly increase with the decrease of coarse aggregate quality, and there are periodic differences in different periods. The SEM images show that the interfacial transition zone of low-quality aggregate concrete is obviously different before and after corrosion. According to the fitting formula of corrosion depth and corrosion time, the concrete prepared by three kinds of quality aggregate can meet the requirements of hydraulic structure in soft water environment, and the recycled coarse aggregate concrete with low quality (class Ⅲ) can be used for the hydraulic engineering structure with 50 years of service.

Abstract:By employing response surface methodology (RSM), the influence of three factors, i.e. water-binder ratio (M/C), aggregate ratio (G/C) and the mass ratio of magnesium oxide to phosphate (M/P), at different temperatures (0， -20 ℃) on the compressive strength and flexural strength of magnesium phosphate cement concrete was investigated. By using Design-Expert software to analyze data, the regression model was obtained, which reflects the influence of three factors on the mechanical properties of MPC concrete at different environmental temperatures. The degree of influence of these three factors on the concrete strength under low temperature was: W/C>M/P>G/C. The compressive strength and flexural strength of MPC concrete decreased with the increase of W/C. The compressive strength and flexural strength of MPC concrete decreased with the increase of G/C, increased with the increase of M/P at -20 ℃. The compressive strength increased with the increase of G/C, decreased with the increase of M/P at 0 ℃; The flexural strength decreased with the increase of G/C, decreased with the increase of M/P at 0 ℃. The 7 d compressive strength and flexural strength of MPC concrete at -20 ℃ showed its maximum value at W/C=0.14, M/P=5.0, and G/C=2.0, whilst the 7 d compressive strength of MPC concrete at 0 ℃ reached its maximum value at W/C=0.14, M/P=3.0, and G/C=3.0; the 7 d flexural strength of MPC concrete at 0 ℃ reached its maximum value at W/C=0.14, M/P=3.0, and G/C=2.0. The deviation between the predicted strength of the model and the actual value of the test was less than 10%, confirming the good significance of the model established.

Abstract:Current findings show that an appropriate indoor thermal environment in educational buildings benefits both the learning efficiency and the building energy performance. These findings emphasize the importance of providing comfortable indoor thermal conditions within these buildings. However, research on thermal comfort in educational buildings is mainly conducted in developed areas rather than in underdeveloped areas. To fill the gap in the understanding of indoor thermal environments and thermal comfort of university buildings in underdeveloped areas, a field investigation was performed in naturally ventilated university buildings in underdeveloped area (Zunyi) within the hot summer and cold winter zone (HSCW) of China during the wintertime. The influence of non-physical factors (e.g., economic level, past thermal experience and thermal expectation) on thermal comfort is also explored. The results show that due to the poor winter indoor thermal condition, 38.3 % of subjects feel "cool" or "cold". The neutral temperature and the 80% acceptable temperature range are 17.36 ℃ and 14.97-20.69 ℃, respectively, which is lower than that predicted by the PMV-PPD model. The comfortable temperature mean value derived by applying the Griffiths' method is 16.88 ℃. The impact of non-physical factors on thermal comfort is demonstrated by the lower values of both the neutral temperature and the lower limit of 80% acceptable temperature zone, comparing with that in developed area cases of HSCW zone. Therefore, it clarifies that passive strategies can be considered when improving winter indoor thermal environment in naturally ventilated university in Zunyi.

Abstract:Airborne bacteria especially pathogens and probiotics, have harmful/beneficial effects on the human respiratory system and skin system. The distribution of these bacteria varied with different temperature and relative humidity. In this study, two working conditions: intermittent cooling and continuous cooling of air conditioners was set up to explore the differences in the temporal and spatial distribution of culturable total bacteria, pathogen (Staphylococcus aureus) and probiotics (Lactococcus aureus). The results showed that the average concentration of total bacteria in intermittent cooling （(1 195±511） CFU/m3) is 2.5 times that in continuous cooling （(483±199） CFU/m3); the average concentration of Staphylococcus aureus was in intermittent cooling （(544±299） CFU/m3) is 4 times that in continuous cooling （(136±7） CFU/m3); the average concentration of Lactococcus aureus was not different in the continuous （(77±40） CFU/m3) and intermittent （(73±24） CFU/m3) cooling. The concentration of total bacteria and Staphylococcus aureus fluctuated greatly in intermittent cooling. In intermittent cooling, the bacterial concentration changed significantly in different sites of the room. However, in continuous cooling, the bacterial concentration varied not obviously. On the spatial scale, the concentration of total bacteria and Staphylococcus aureus increased with the increase of the horizontal and vertical distance from the air conditioner, and decreased with the increase of the longitudinal distance from the air conditioner. In intermittent cooling mode, the risk of bacterial exposure in children's respiratory area (z=0.5 m) is higher than that of adult's respiratory area (z=1.5 m). The concentrations of total bacteria and Staphylococcus aureus were significantly positively correlated with temperature (p<0.001). However, there is no obvious correlation with relative humidity. In summer, using air conditioner can significantly reduce the concentration of cultivable bacteria in the room, which may benefit to our health.

Abstract:In recent decades, atmospheric-pressure plasma technology has been rapidly developed in the field of water treatment, and has a good application prospect, but it still remains a challenge to reduce operating energy consumption and improve processing efficiency for industrial applications. In this paper, a simple and industrially scalable prototype of plasma reactor based on dielectric barrier discharge (DBD) at atmospheric-pressure air condition is employed to the methylene blue(MB) simulated dye wastewater with complex structure and stable performance. The effects of discharge voltage, air volume, initial concentration, initial pH and initial conductivity on the treatment of methylene blue wastewater are studied. The contribution of ·OH in the treatment of methylene blue wastewater by dielectric barrier discharge reactor is quantitatively analyzed. The study further uses the Box-Behnken response surface method to find the optimal operating parameters of the system: initial pH4, discharge voltage 13 kV, initial concentration 100 mg/L. The results show that the device can effectively treat methylene blue wastewater. After 15 minutes of discharge under optimal conditions, the MB degradation rate was 95.39%, the energy efficiency was 14.87 g/kWh, the reaction rate constant was 0.202 6 min^-1, and the reduction rate of the chemical oxygen demand (COD) value is 62.63%, the chromaticity change is also obvious, indicating that the device can be industrially applied to the treatment of organic dye wastewater.