Papers by Keyword: Cation Exchange

Abstract: The evolution of mankind from Paleolithic Era to the current big Era Nine has also found versatile applications of various plastic polymers owing to some desirable properties like mechanical strength, poor electrical and thermal conductivities and as a result, subsequent generation of its wastes are thriving up. Basically plastic polymers are synthetic organic matter containing hydrocarbons having high potency for thermal decomposition for producing alternate fuel. Thermo-Catalytic reaction process of high-density polyethylene (H.D.P.E.) & polypropylene (P.P.) mixed waste is investigated by using fly ash-derived silica–alumina catalysts and bentonite clay powder. The aim of the work is to find the optimum parameters of the process with locally processed catalysts in terms of their degradation temperature and yield. The thermal degradation of H.D.P.E. & P.P. mixed waste in the presence of catalysts is done with pyrolytic environment in a pilot scale stainless steel reactor with the continuous rated supply of nitrogen and L.P.G. heating. The process parameters are measured with thermocouples, flow control devices. Fly ash and bentonite are synthesised in a lab scale and used as catalysts. A series of pyrolytic experiments are conducted with the synthesised catalysts and commercial catalyst Zeolite-Y Hydrogen to demonstrate the optimum operating parameters on yield of mixed waste H.D.P.E. & P.P. derived hydrocarbon oil.

Abstract: With the development of the coastal cities, land reclamation has become an important part in the construction of coastal engineering and the coastal development projects. In this paper, we consider the dredger fill of Tianjin Textile Economic Region as the research subject, analyzing the engineering geological characteristics of the dredger fill in this area from its basic physical properties, the soluble salt of the study area, the variation laws of PH and cation exchange properties.

Abstract: In order to study the process of ionic soil stabilizer (ISS) reinforcing different kinds of soil, kaolin, red clay, landslide soil, expansive soil and quartz sand ,the five kinds of standard soil samples were treated by ISS of ratio 1:100. After 24-hour soaking and oscillation treatment, the supernatant was detected by laser-induced breakdown spectroscopy (LIBS). Comparing with the samples had not been treated by ISS, got the information of cation exchange. Experimental results showed that, the cation exchange in different soil was various, landslide soil exchanged more cation, and the cation exchange of kaolin and quartz sand was less. These studies will provide the experimental basis for ISS reinforcing mechanism research.

Abstract: In order to investigate the effect of bentonite binder on adsorption and cation exchange properties of granulated nano NaY zeolite, the adsorption of Xe and N2 and removal of Sr2+ ion from aqueous solution was studied. The results showed that increase in bentonite content of granules from 20 to 40 weight percent caused increase in the rupture load of granules by 232%, decrease in BET surface area by 66% and lower the Sr²⁺ uptake percentage by 35%. The Henry’s law constant, heat of adsorption, effective crystal diffusivity as well as activation energy of diffusion of Xe over granulated nano NaY with 25% bentonite was also measured by pulse chromatography method. Obtained results were compared with similar results of binderless micron sized NaY material. Results indicated that although the adsorption of xenon on the binder of bentonite was negligible, the diffusion resistance created by this binder was significant such that the effective crystal diffusivity in the granules with 25% binder determined to be 4302 percent lower than the granules with no binder.

Abstract: The performance of the alkaline processes on the properties of cation exchange capacity (CEC) and swelling was studied in three different types of bentonite from Brazil, Argentina and Mozambique. Alkaline activations were performed by means of mechanochemical reactions with solutions of NaOH and Na2CO3, to increase the sodium content of bentonite clays and, thus, improve the properties above. Clay samples were characterized by X-ray diffraction, to obtain the constituent phases. Activated samples were evaluated according to their cation exchange capacity – determined by the methylene blue test, and swelling index – measured by the Foster’s method. Results showed that the activation improved the properties of all bentonite types, especially the Brazilian clay, which achieved the most significant raises. There was also an indication that the type of clay affect the processing.

Abstract: Based on good cation exchange property of vermiculite，the adsorption of vermiculite for simulated radionuclide Sr was studied by the static adsorption method. The adsorption behaviors and the effect of the experimental conditions were investigated. The results show that the saturated adsorption capacity of vermiculite sample for the simulated radionuclide Sr was 8.246×10-2 mmol/g. The suitable pH value ranged from 4 to 11, the balanceable adsorption time was 3d, and the suitable temperature was 30°C. The main adsorption type was cation exchange. The adsorption mechanism can be described by Langmuir and Freundlich models. It acts better in accord with Langmuir model, and the correlation coefficient is 0.99974. This experimental study has important significance on low concentration of Sr radioactive waste liquid treatment.