Papers by Keyword: Attapulgite

Abstract: High-density polyethylene (HDPE) is used as the matrix and attapulgite (ATT) is used as the reinforcing phase. HDPE/ATT nanocomposites are prepared by melt blending. The effect of ATT content on the mechanical properties, water absorption and morphology of HDPE/ATT composites was studied. The results show that adding a small amount of ATT can improve the mechanical properties of HDPE, but excessive addition will reduce the mechanical properties of HDPE. The water absorption and contact angle test results show that as the ATT content increases, the composite material becomes more and more hydrophilic. After joining ATT, the performance of HDPE / ATT composite material has a significant improvement effect, and it is believed that it will have broad application prospects in the future.

Abstract: Attapulgite (AT)-based nanofibrous membranes (NFMs) were fabricated via a facile papermaking procedure, and the AT-based NFMs were sintered at three different temperatures (240 °C, 400 °C, and 600 °C). The effect of sintering temperature on the structure and properties, such as specific surface area, pore size distribution, porosity, mechanical property, pure water fluxes of AT-based NFMs, were investigated. The results showed that average pore size, total pore volume, and porosity of AT-based NFMs increased with increasing of the sintering temperature, while specific surface area and flexural strength of AT-based NFMs decreased. The optimal sintering temperature for AT-based NFMs was 400 °C. In addition, it was also found that the swelling degree of AT-based NFMs in aqueous solutions was suppressed and the pure water fluxes of AT-based NFMs were improved by sintering process.

Abstract: Polyacrylic acid/attapulgite (PAA/ATP) composite hydrogels used for removal of heavy metal ions from aqueous solution was synthesized via radical polymerization with acrylic acid (AA) and attapulgite (ATP) modified by hydrochloric acid as adsorbent. Chemical composition of the modified ATP was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) and the morphology of the PAA/ATP hydrogels was characterized by scanning electron microscope (SEM), respectively. The swelling ratio, pH-sensitivity and adsorption performance of Ni (II) ions of the composite hydrogels were studied. The results showed the swelling ratio of the PAA/ATP composite hydrogels was higher than that of PAA hydrogels and the composite hydrogels displayed sensitivity to pH values with a sharp increase of swelling ratio when the pH values increased from 4 to 6. Comparing with PAA hydrogels, the composite hydrogels obtained a larger adsorption capacity of Ni (II) ions, the average adsorption capacity could reach 72.8 mg/g and adsorption ratio could reach 84%.

Abstract: Degradation of yellow bright anionic dye under ultraviolet radiation was studied using attapulgite (ATT) as a support in the immobilization of the photocatalyst semiconductor, titanium dioxide, TiO₂. The photocatalytic performance of the corresponding catalyst was evaluated using the 1.0x10^-4 mol L^-1 concentration of the dye. The samples were irradiated with UV light for 120 minutes. The kinetics were monitored by UV-Vis spectrophotometry. The spectra absorption showed that the increased amount of photoactive material in the reaction system maximizes the efficiency of the photocatalytic process.

Abstract: Cement-based solidification/stabilization (S/S) has been considered as an effective method to deal with hazardous wastes such as textile dyeing sludge. In this study, sludge from textile wastewater treatment plant was solidified by Portland cement and attapulgite at different mass ratios (sludge 0.1~0.8, cement 0.1~0.8, attapulgite 0.1~0.8), and the characteristics of the solidified blocks were evaluated. The maximum unconfined compressive strength (UCS) of 15.8 MPa was obtained at 28 d when the mass ratio of attapulgite, sludge and cement was 0.1:0.1:0.8, while in toxicity characteristic leaching procedure (TCLP) test, relatively low concentrations of COD (100~150mg/L) in the leachate were found when the mass ratio was set to 0.3:0.1:0.6. Results of XRD and SEM/EDS indicated the existence of calcium silicate hydrate (CSH) in the solidified blocks. ANOVA results proved that the quadratic model could be utilized to characterize the relationship between COD of the leachate and the components in the mixture.

Abstract: Environmental minerals, such as bentonite, kaolin, talc, attapulgite and diatomite, have abundant micropores and surface active groups. Preparation of hydrogels based on the minerals have been drawing more and more attentions worldwide because of improved salt resistance, water absorption rate, gel strength, thermal stability, water holding capacity due to addition of the minerals. Current investigations mainly focus on water absorption performance of hydrogels, insufficient concerns about porous structure, cohesiveness, surface electrical characteristics, corrosion resistance and thermal stability were paid. Novel preparation techniques with aid of ultrasonic treatment and microwave irradiation, enhancing in-situ grafting and copolymerization of biomass cellulose in mineral structures, as well as further researches on absorption mechanism of environmental mineral based hydrogels are becoming meaningful trends.

Abstract: Adsorption of Cu(Ⅱ) onto natural attapulgite was investigated with respect to temperature, initial concentration and contact time. The adsorption process can be well described by the pseudo-second-order kinetic model, and the equilibrium adsorption isotherm was closely fitted with the Freundlich model. Enthalpy change(△H⁰), entropy change(△S⁰) and Gibbs free energy change(△G⁰) were calculated from the temperature dependent sorption data, and the results indicated that the sorption of Cu(Ⅱ) on attapulgite was a spontaneous process, and the sorption was endothermic.

Abstract: The adsorption behavior of Zn (II) by attapulgite were studied in the paper, The effects of adsorbent dose. Contact time, ionic strength and temperature on the adsorption were investigated. The maximum adsorption capacity is 4.129 mg.g^-1 at 333 K. The kinetic study indicated that the adsorption was a pseudo-second-order process. The adsorption was well fitted by the Langmuir adsorption isotherm model. The results indicated that the sorption of Zn (II) by attapulgite was a spontaneous process, and the sorption was endothermic.

Abstract: A novel desulfurizer was prepared to remove the sulfide in MTBE. The performance of the desulfurizer was investigated by L₁₈(2×3⁷) Orthogonal Test. The desulfurizer for MTBE was prepared by the impregnating technique, in which the transitional metal Fe series and Ag series compounds were used as active components, and the modified attapulgite clay as the carrier. In order to get the optimum conditions to desulfurization in MTBE, IR, XRD, TEM, XPS technology were used to study the desulfurization mechanism. Compare the desulfurization characterize before and after the experiment. The result shows that the desulfurizer made by 8% Fe series compound and 2% Ag series compound, and roasted at 300°C for 3 hours. The Sulfur content in MTBE was reduced from 789mg/kg to 124mg/kg. The desulfurization rate was reached to 84.18% (in normal temperature and pressure.). The removal effect is obvious. The result of this study can be applied for Removal sulfide in MTBE.

Abstract: The poly (butylene succinate) (PBS) and 3 wt% attapulgite (ATP) reinforced PBS/ATP nanocomposites with 1,6-hexanediol were fabricated using an in situ polymerization method. The crystallization behaviors indicated that ATP had effectively acted as nucleating agent, resulting in the enhancement on the crystallization temperature. The SEM results showed a superior interfacial linkage between ATP and PBS. Also, ATP could disperse as a single fiber and embed in the polymer matrix, which resulted in the improved mechanical properties.