Advanced Materials Research Vols. 634-638

Abstract: CaSO₃ and CaO are main components in solid waste from flue gas semi-dry desulfurization process. A series of slag cements were prepared from cement clinker and blast furnace slag, in the process of which CaSO3 and CaO were added. The composition and macrostructure of the derived cements were studied in detail with the aid of XRD and SEM. Furthermore, the influence of amount of CaSO₃ and CaO on the mechanical properties and setting time for slag cement were evaluated, the mechanisms of which were also discussed. The results show that due to the formation of AFt and AFm in the hydration process, the CaSO₃ has an obvious setting retarding effect on the slag cement, and quality slag cement can be obtained when the amount of slag and CaSO₃ are 20% and 2%, respectively, the compressive strengths of which at 3, 7, 28 d are 30.8, 39.1, 53.7 MPa, and bending strengths at 3, 7, 28 d are 9.6, 10, 11.9MPa, respectively. Besides, CaO added which can play a role of alkali-activator for slag cement can not cause the soundness problem of slag cement.

Abstract: Oxidation of the textiles dyeing wastewater was studied in a continuous-flow reactor that was operated between 400 and 650°C at a fixed pressure of 25 MPa. The total organic carbon (TOC) concentration of the raw wastewater was in the 112.52 mmol/L . Hydrogen peroxide (H2O2) was used as an oxygen source. According to the wastewater and oxidant concentrations, the global rate expression was regressed from the complete set of data under various conditions of the reaction. The reaction rate expression for the oxidation of the textiles dyeing wastewater was determined with the activation energy of 39.908 (±1.99) kJ/mol and the pre-exponential factor of 114 (±7.5) /s; and the reaction orders for the TOC and the oxidant were 0.896±0.01 and 0.061±0.01 at a 95% confidence level.

Abstract: The grafting copolymerization was studied for improving the filtration efficiency of the PP melt-blown non-woven. The experiment was made of three steps: firstly, the optimum conditions were attained by the orthogonal experiments; secondly, the effect regularities of main factors on reaction were discussed; thirdly, the water absorbability and the structure of the grafted sample were analyzed. The results show that the water absorbability of the grafted product significantly improves.

Abstract: The research adopts the raw material of 89% slag with the composite activators and the compressive strength, hydration heat, temperature and expansion property of the material are studied. And the new cementitious material is obtained with the properties of low-heat and small expansion, convenience-confect, easy-operation and need no mass production. This material has the remarkable economic profit and good application foreground especially in the mass grouting engineering.

Abstract: A new recycle technology of spent catalyst from furfuryl alcohol production by furfural hydrogenation has been developed. The approach is a process of dissolution in sulphuric acid under high temperature and high pressure condition. After removing the organic species, the spent catalyst of furfural hydrogenation was mixed with sulphuric acid, and reacted for 1h, 2h, 3h, 4h and 5h at 120°C, 140°C, 160°C, 180°C and 200°C, respectively. The content of copper in filtrate was analyzed by iodimetry. Effects of important variables, such as sulphuric acid concentration, reaction time and temperature, etc., were investigated for determining the optimum conditions. The optimum conditions of maximum leaching rate of spent cupric and chromic catalysts were determined by orthogonal experiment as follows: 80% sulphuric acid, reaction temperature 190°C and reaction time 4h. Under these conditions, the recycling rate of spent cupric and chromic catalysts was more than 93%.

Abstract: Treatment of retting hemp waste water was made by the synergy of activated carbon and microwave in this experimental investigation, and the four factors that influenced the experimental results were considered in which there were respectively the material ratio of activated carbon dosage and retting hemp waste water volume, microwave radiation power, microwave radiation time and the initial pH value of retting hemp waste water. The experimental results showed that, while the material ratio was 7:50 (i.e., the quality of activated carbon was 7g as the volume of retting hemp waste water was 50mL), the microwave radiation power and the microwave irradiation time were respectively 320W and 13min, and the initial pH value of retting hemp waste water was just 2, the treatment effect of retting hemp waste water was best in this experimental investigation.

Abstract: One of difficult pollution control tasks for leather plants is the dimethylamine wastewater treatment. It is identified that there are two serious problems occurring in the current treatment process: low removal efficiency and low recycle efficiency. To solve these problems, new-type high efficiency packing and wastewater treatment process are proposed. The rectifying conditions of dimethylamine wastewater were investigated in a laboratory continuous distillation tower. Dimethylamine distillation efficiencies of no less than 47% at the top of tower was obtained, when the bottom temperature was controlled between 105～106°C, reflux ratio between 2～3, Final concentrations of less than 50 mg•L-1 at the bottom was obtained.

Abstract: A Trimethoxysilane modified polymer flocculant (PMCAD) was synthesized and applied in wastewater from effluent A/O bioreactor. The turbidity removal, color removal and zeta potential of flocculant PMCAD were determined through the treatment of coking wastewater from A/O bioreactor. Results showed that flocculant PMCAD was more efficient for turbidity removal than that of PAM. The largest removal rates of turbidity and color were 94.44 % and 67.78 % respectively at the dosage PMCAD of 200 mg/L at pH 7. the zeta potential of flocs for coking wastewater increased as the PMCAD dosage increased from 100 to 600 mg/L at pH 7.

Abstract: Through the method of the static tests, the removal rate of aqueous dichloroethylene onto a new TCAS-loaded resin was researched. This TCAS-loaded resin was made of a novel supramolecular acceptor compound named thiacalix[4]arenetetrasulfonate(TCAS) and anion exchange resin, and the adsorption mechanism was discussed preliminarily. The results of adsorption indicated that the pH value was an important factor for the removal of dichloroethylene and it would be better for the adsorption if the pH value was greater than 6. The operating temperature should be controlled in 5 to 15°C for the adsorption of dichloroethylene onto TCAS-loaded resin while the removal rate decreased with the temperature increasing and the best time for reaction was 40min. The removal rate of dichloroethylene in aqueous solution was better when 25mL aqueous solution of dichloroethylene (1.0mg/L) was adsorbed by 0.5g TCAS-loaded resin. The dichloroethylene can be resolving and TCAS-loaded resin can be reused.

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 degradation、initial solution concentration 、initial pH value、the 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／L、initial pH value was 7、the amount of catalyst was 0.6g,moreover the adding of Fenton could greatly enhance the degradation rate.