Advanced Materials Research Vols. 781-784

Abstract: A non-fired brick were manufactured by solidification of modified dredged soils. A novel solidified agent based on industrial wastes was prepared. A typical manufacture process of the non-fired brick comprised of mixing, stirring, tamping and maintaining. Several tests and measurements were conducted according to Chinese Professional Standard and National Standard. The results showed that the non-fired brick exhibited excellent performances and low toxicity. The non-fired brick was found to be a suitable material for use in the civil architecture.

Abstract: In this research, improved granulation based on partly hydration of red mud was combined with gelling materials. Nitrogen and phosphoric salt were added in during granulation. Soil samples were collected periodically to evaluate the changes of pH, Z-potential and enzymatic activities of urease, catalase and alkaline phosphatase of soil. And the correlations among them were analyzed. Increase of pH that was caused by strong alkali was slowed by applying of composite particles. Dissolved phosphorus greatly inhibited all enzymatic activities while reinforcing restoration.

Abstract: Through the analysis of size composition, ash and other properties of Qidong coal mine, three kinds of coagulants and flocculants are used to do the settlement test. The concentration of coal slime water, the types and effect of flocculant and coagulant on the settling are also studying. The research shows that when the concentration of coal slime water is 50g/L, 75g/L and 100g/L, the best flocculant is APAM whose dosage is respectively 4g/m3, 8g/m3 and 12g/m3, and the optimal coagulant is poly-aluminum whose dosage is respectively 150g/m3, 700g/m3 and 1100g/m3. In addition, the coal slime water flocculation will get a better result if the flocculant is added later than the coagulant.

Abstract: A series of gasification experiments of MSW RDF was made by using independently developed gasification device. When MSW RDF gasified at 200°C ~900°C, the trend of instantaneous gas production was increased, decreased, then increased rapidly after downward, 2 peak of instantaneous gas production were 500°C and 800 °C. When the gasification temperature is below 400 °C, except for CO, the content of various combustible gases are rarely. With the increase of the gasification temperature, bottom ash content decreased, but tar yield and volume percentage content and calorific value of the combustible gas increased gradually. when the gasification temperature reached 900°C, the calorific value of combustible gas reaches the highest, 28MJ/m³, bottom ash reaches the lowest, only 12%. Tar reached the highest value at 600 °C ~700 °C, about 40%.

Abstract: Comparison analysis of linear least square method and nonlinear least square method for estimating the kinetic parameters was made using the experimental column data of Light green adsorption onto a cationic surfactant hexadecylpyridinium bromide (CPB) modified peanut husk (MPH) at different flow rate and initial concentration. The data were fitted to Thomas model equations using linear and non-linear regressive analysis, respectively and the error analysis was performed. The results showed that both methods are suitable to predict the breakthrough curves using Thomas model parameters and the nonlinear method is better.

Abstract: Organophosphosphous pesticides wastewater was degradated by sonophotocatalytic oxidation technology,and some factors affecting sonophotocatalytic oxidation reaction were studied in details such as different degradation modes,the time of degradationinitial solution concentration initial pH valuethe amount of catalyst and the effect of Fenton,etc.In the end the optimal conditons were determined.The conclusion we drawed was that the optimal time of degradation was 100min initial solution concentration was 100mg/Lthe amount of catalyst AgBr/TiO₂ was 0.6g,moreover the adding of Fenton could greatly enhance the degradation rate.

Abstract: The adsorption of Cr(VI) by modified peanut shell has been investigated using chemical methods and IR spectrometry. The optimal condition for the adsorption of Cr(VI) by modified peanut shell is at 308 K and pH = 1.0, which gives a static saturated adsorption capacity of 14.15 mg·g-1, an apparent adsorption rate constant of k298 = 2.43 × 10-4 s-1, and an apparent adsorption activation energy of 10.58 kJ·mol-1. The adsorption follows the Langmuir and Freundlich isotherms and the liquid film diffusion is the controlling process of the adsorption. The adsorption thermodynamic parameters are ΔH = 125.58 kJ·mol-1, ΔS = 0.473 9 kJ·mol-1·K-1, ΔG = -17.81– -27.27 kJ·mol-1. Small amount of desorption is observed only at pH > 11. Adsorption mechanism of modified peanut shells for Cr(VI) was both physical adsorption and chemical adsorption of adsorbent "adsorption-oxidation and reduction processes".

Abstract: In order to make a further understanding of flow pattern and back mixing in the flotation process, the study about particle residence time distribution of collection zone in a packed column has been designed. The pulse tracer method was applied and the particle tracers were the mineral gangue in special size class. The residence time distribution curves of our experiment data shows that there are particle back mixings which were caused by fluid flow and geometry factors in the column. The tank-in-series model has a better fitting to the particle residence time distribution in the column according the comparison research between the tank-in-series model and axial dispersion model. The operation parameters have different effects on the particle residence time distribution according to our experimental study.

Abstract: The MDEA-PZ binary system and the MDEA-PZ-MEA/DEA/ETA/TETA ternary system were used to absorb CO₂ from the simulated flue gas. The experimental results showed that the best performance of the absorption of CO₂ was achieved under the mass ratio of MDEA to PZ of 10/4 in the MDEA-PZ binary system. In the MDEA-PZ-MEA/DEA/ETA/TETA ternary system, due to the different molecular structure of the additives, the absorption performance of CO₂ was determined as follows: MDEA-PZ-TETA>MDEA-PZ-ETA>MDEA-PZ-MEA>MDEA-PZ-DEA. In the MDEA- PZ- TETA ternary system, the better absorption performance could be reached at the volume ratio of MDEA-PZ to TETA of 1:2. Moreover, it was indicated that there was a weakly negative interaction among MDEA, PZ and TETA.

Abstract: A dewatered sludge was treated in three barrel fermentation systems to produce garden nutritional soil in aerobic, anaerobic or aerobic-anaerobic alternative method respectively. Varitation of fermentation temperature, number of coliform groups, available nitrogen, available phosphorus, total potassium, humus content and other indexes under different fermentation processes were studied. Results showed that the sludge in aerobic method has the characteristics of high temperature, warming fast and killing coliform effectively, but having a high degree of mineralization of organic matter and a low degree of available nitrogen, phosphorus and humus, while in anaerobic method on the contrary. Aerobic-anaerobic alternative method raised the available nitrogen, phosphorus, total potassium and humus content, meeting the demand of harmless, nutrition and humification indexes. In energy consumption perspective, the alternative method save energy by 75%. Summer and winter tests showed that alternative method for fermentation sludge into garden nutritional soil is feasible.