Advanced Materials Research Vols. 864-867

Abstract: For optimizing the structure design of the wave-plate demister vanes in wet flue gas desulfurization system (WFGD) of power plants, the characteristics models of removal efficiency and pressure drop were established by using least squares support vector machine (LSSVM) based on numerical simulation results. The highest relative error between the predicted output and measured value is 2%, it proves the modeling is good for the prediction. Based on the characteristics models, a multi-objective optimization model was established. It used the structural parameters as the optimal variables and the demister characteristics as the objective function. This optimization model was solved by non dominated sorting genetic algorithm (NSGA-II). The simulation data show that the Multi-objective optimum method can get more effective results compared to the weight coefficient method.

Abstract: Soil pollution around railroad sites is mainly caused by heavy metals and oils. In this study, electrokinetic (EK) remediation was tested to remediate the heavy metal-contaminated railroad soil. The main pollutants of the soil were Cd, Cu, Pb and Zn. The used reactor was 2-D scale and DC electric current was supplied continuously under 2 V/cm. As a result, the total removal efficiency of heavy metals from the contaminated railroad soil was about 55.2 %. In the future, the additional researches are required to enhance the removal efficiency for the residual concentration of heavy metals in soil under the remediation standard levels designated from the Soil Environment Preservation Act in Korea.

Abstract: Supercritical water oxidation (SCWO) has a promising future for treating high concentration and bio-refractory organic wastewaters. However, the reactor plugging problem induced by salt deposition has hindered its extensive commercial application. In this work, we used a continuous-flow experiment plant to systematically examine the influences of the pressure, temperature, running time, initial concentration and flow rate on the deposition properties of Na₂CO₃ under supercritical water conditions. Two parameters including the deposition ratio (R) and the deposition rate (V) were defined to evaluate the deposition extent of Na₂CO₃ in the reactor. The results showed that the pressure and temperature had remarkable influences on the R and V of 1 wt% Na₂CO₃, and their increase would make R and V reduce. The running time had slight effect on the varieties of R and V. Both R and V would rise with the initial Na₂CO₃ concentration increasing. However, V had a reverse change tendency compared with R as the flow rate rose. The R and V of 1 wt% Na₂CO₃ with the flow rate of 0.65 L/h at 550 °C and 25 MPa were higher than 80% and 64 μm/h, respectively. This meant a high reactor plugging risk under the long-time run conditions. Moreover, NaOH was not suitable as the alkali neutralizer of the SCWO process at the low velocity condition in the reactor.

Abstract: Regarding the iron filing as PRB padding media, this experiment researched the repair effect of iron filing to the groundwater polluted by Cr on condition that different initial concentration of Cr6+ and different flow velocity, and then with the help of the data regression analysis software SPSS、1stOpt、Excel etc, it studied the regression analysis of Cr6+ removal rate with the change of initial concentration and the flow velocity. The results indicated that: under the certain flow velocity, cubic polynomial is the best regression model of Cr6+ removal rate with the change of initial concentration;under the certain initial Cr6+ concentration, the change of Cr6+ removal rate with flow velocity can be fitted in the regression model of unitary linear well, and the decision coefficient R2of it can be up to above 0.9.

Abstract: This paper aims to improve the separation of fine solid particles in mini-hydrocyclones by changing the shape and size of the mini-hydrocyclone inlet. This study also examines the best mini-hydrocyclone inlet shape and size. Fluent software is used to simulate the flow field of the continuous and dispersion phases in different mini-hydrocyclone. The simulation results can guide the design and optimization of mini-hydrocyclones and determine the optimum inlet aspect ratio.

Abstract: Three kinds of Ti/SnO₂ based electrodes were prepared by thermal decomposition method. The surface morphologies were characterized by SEM, the electrochemical properties were investigated by linear scan voltammetry, CV(cyclic voltammetry), constant current electrolysis. The results show that Ti/SnO₂-Ru/SnO₂-Ce electrode exhibits high oxygen evolution potential and excellent performance of hydroxide radical generation. The removal ratio of 5, 7-dimethyl-2-mercapto-1,2,4-triazole pyrimidine as pollutant in simulated wastewater is up to 89.7% and of COD is 40.4%.

Abstract: Optimization of coagulation conditions in the granulation-coagulation process for strontium removal was studied in this paper. The experimental results showed that the optimum coagulant was aluminum sulfate. The optimum coagulation conditions were dosage of 60 mg/L, coagulation time of 10 min, mixing speed of 180 r/min. The best combination method was granulation - coagulation - sedimentation. Under optimal conditions, the DF of strontium was 87 and the effluent turbidity was 1.05 NTU.

Abstract: A Novel adsorption apparatus for processing hazardous chemicals diffusion and volatilization of inland waterway transportation is developed. The adsorption apparatus is lightweight and has high effective absorption capability for processing the gas chemicals produced by inland river transportation. Meanwhile, the experiment for analysis and processing for the bulk chemicals gas is carried out. The results showed that the concentration of chemicals gas decreased by 69-83% comparing with that not using the device.

Abstract: Red phosphorus microencapsulation flame retardant was prepared by Supercritical Fluid-Rapid Expansion of Supercritical Solutions (SCF-RESS),using a self-made special nozzle. The influences of the reversed gyrator, and the rotation angle of the front revolvable tie-in on coating effect were discussed. The results showed that the coating effect which the reversed gyrator was installed on the nozzle was better than it which the reversed gyrator was not installed on the nozzle.The coating effect is the best when the rotation angle of the front revolvable tie-in is 10°,and the coating effect is worse when the rotation angle of the front revolvable tie-in is exceed 10°.

Abstract: As an emerging technique, carbon dioxide capture and storage (CCS) is to mitigate greenhouse gas emissions. Deep saline aquifers are increasingly considered because of their wide distributionlarge thicknesslarge capacity. A proper understanding of displacement character of supercritical CO2-brine system is significant in knowing CO2 Injectivity, migration and trapping, and in assessing the safety and suitability of reservoir site. CO2-brine system is multi-phase flow system, the mobility is related to interfacial tensioncapillary pressurerelative permeability. The experiments took into account the impact factors such as interfacial tensioncapillary pressurerelative permeability, foreign indoor experiments of CO2-brine system are analyzed and summarized, a brief description of indoor experiments of our country and future work are given.