Advanced Materials Research Vols. 573-574

Abstract: The sorption performance of tetracycline (TC) on HCl-modified zeolite under different conditions was investigated. HCl-modified zeolite exhibited more than two times higher adsorption capacity than natural one. Adsorption kinetics and adsorption equilibrium isotherms were studied by conducting series of batch experiments. The kinetic analysis indicated that the pseudo-second-order kinetic model was well described the sorption equilibrium process of tetracycline onto natural and HCl-modified zeolites, and intra-particle diffusion was not the only rate-limiting in the sorption process. The results from sorption equilibrium studies showed that the Langmuir and Dubinin-Radushkevich (D-R) isotherm models were well fitted to experimental data, the value of E confirmed that the adsorption was controlled by physical combined with chemical adsorption mechanism. The sorption removal capacity is relatively higher at low pH. The adsorption removal rate of wastewater containing 0.1 mmol/L tetracycline was 95.5% when the dosage of treated zeolite was 0.05g.

Abstract: Cadmium has been determined by summable spectrophotometry of positive-negative peaks with cadion and Triton X-114 after cloud point preconcentration. Influence factors on cloud point extraction, color reaction and absorbance were investigated by studying the summation absorbance of color compounds at 480 nm and 570 nm. The sensitivity and absorbance of this method are at least five times higher when compared with that of usual cadion spectrophotometry due to the summation of positive and negative peak. The proposed method is sensitive, simple, accurate and environmentally-friendly in the determination of cadmium in environment water.

Abstract: Different types of formaldehyde scavenger were used to remove free formaldehyde in aldehyde tanning leather. The results showed that: the formaldehyde removal effect of self-made aminated collagen (EAC) was the best, followed by hyperbranched polymer with active methylene (HPAM). Then the mixture of EAC and HPAM was used to remove free formaldehyde. The optimum conditions were obtained by single factor experiment. The weight ratio of EAC and HPAM was 1:1 and the processing time was 2h. Finally, EAC, the mixture of EAC with HPAM and chitosan were used to remove free formaldehyde in oxazolidine tanned sheep skin. The comparison results showed that the formaldehyde-removal rate of the mixture of EAC and HPAM reached to 75% which was better than that of EAC and chitosan, but also it had obvious thickening and assisting dyeing effects to leather.

Abstract: The SCR catalysts were produced with V2O5, WO3, MoO3 and anatase type TiO2. The thermo stability of the catalyst with different MoO3 loading was analyzed with TG-DTG. And the SO2 oxidations were researched with a fixed bed reactor under simulated exhaust gas. The different loadings of MoO3 did not effect on the thermo stability of the catalyst with temperature in the test range of 30~1000 °C. The TG–DTG curves of thermal decomposition process of V2O5-WO3-MoO3/TiO2 catalyst showed three mass loss segments: 1st the evaporation of crystal water from 70 °C to 130 °C; 2nd the decomposition of organics from 180 °C to 350 °C; 3rd the decomposition of impurities from 480 °C to 550 °C. The catalyst loading MoO3 showed higher catalytic selectivity compared to the catalysts without MoO3. MoO3 contained in the catalysts prevented SO2 oxidation, improving the oxidation start temperature and reducing the maximum oxidation.

Abstract: The performance of native eggshell membrane in removing of malachite green (MG) from aqueous solution was investigate. The effect of pH, adsorbent concentration, temperature, and contact time were performed by static testing. The maximum biosorption was both observed at pH 6.0 on the eggshell membrane. Optimal adsorption capacity (89.72 mg g-1) at initial concentration 100 mg L-1 and rate (98.69%) was obtained at pH 5.5. Characterization of the biosorbent eggshell membrane was performed using scanning electron microscope (SEM), and Fourier transform-infrared (FTIR) spectroscopy. The kinetic and equilibrium studies suggest that the adsorption follows Langmuir isotherm model. Desorption studies revealed that MG could be well removed from wastewater.

Abstract: The aim of this study was to establish an economical and environmentally benign biosorbent for removing synthetic dyes (e.g. methylene blue, MB) from wastewater. The adsorption process of MB onto abandoned mung bean (Vigna radiata L. Wilczek) shell (MBS) was investigated in a batch system. The results showed that a wide range of pH (3.74 to 9.78) was favorable for the adsorption of MB onto MBS. Equilibrium studies indicated that the Langmuir model displayed the best fit for the isothermal adsorption data. The maximum monolayer adsorption capacity (165.92 mg g-1) calculated by the Langmuir equation was higher than that of many previously investigated low-cost bioadsorbents (e.g., peanut hull, wheat straw, etc.). The adsorption process best fitted pseudo-second-order kinetic model. Thermodynamic studies showed that the adsorption process was spontaneously, exothermic and was mainly a physisorption. This study indicates that MBS is a promising, unconventional, affordable and environmentally friendly bio-measure that is easily deployed for removing cationic dyes from wastewater.

Abstract: In this paper, the surface finishing process of anti-alcohol, anti-oil and antistatic was applied on terylene needle-punched nonwoven filter material. We used contact angle, anti-alcohol grade, anti-oil grade, static voltage and half-life period as the main indicators for evaluating the effect of the finishing. The organic fluorine TG-410C and nonionic antistatic agent TF-481 were selected as finishing agents. The single factor experiments and orthogonal experiments were carried out on four effect factors of the finishing, including volume percent of organic fluorine, volume percent of antistatic agent, baking temperature, baking duration. The results show an optimum formula: the volume percent of organic fluorine is 20%, the volume percent of antistatic agent is 15%, baking temperature is 170°C, and baking duration is 7min. After finishing, anti-alcohol grade can reach level eight, anti-oil grade can reach level five; the half-life period is less than 1 second. So it can be employed in filtering the air and reducing dust particle and concentration.

Abstract: Hydrotalcite-like compounds containing Mg2+, Al3+ and Fe3+ with a constant M2+/M3+ ratio but varying Al3+/Fe3+ ratios have been prepared. The effects of iron contents on the structural and sorption of Pb2+ by Mg-Al-Fe HTlc samples were investigated. The maximum sorption amounts were about 88-201 mg/g for Mg-Al-Fe HTlc samples. The sorption isotherm and kinetic processes can be described with Freundlich isotherm and pseudo first order kinetic model, respectively. The sorption amounts and rate increase with the increase of iron contents in HTlc samples. The sorption mechanism of Pb2+ on Mg-Al-Fe HTlcs may be the surface-induced precipitation and chemical binding adsorption.

Abstract: The present study was to investigate the production of aerated concrete block from ChangJiang iron ore gangues. Analyze Quartz Sand, cement, CaO and gangue’s ratio’s influence on the aerated concrete block’s compressive strength, and then determine the optimum ratio. The results shows that gangue, quartz sand, cement, CaO, gypsum, aluminum powder, additive’s optimum ratio is 60.11%，8.26%，15.03%, 14.07%, 2%, 0.06% and 0.07% the dry weight of raw materials. Obtain the strongest compressive strength with the ratio 0.59:1 for water and raw materials. Adding iron gangues into aerated concrete block can turn wastes into treasures, which is originally done by us.

Abstract: The “Twelfth Five-Year” plan of China starts at the emission reduction task in controlling the total amount of ammonia nitrogen. Therefore, the method of how to remove ammonia nitrogen quickly and effectively will be the key point of wastewater treatment. In the current paper, One zeolite synthesized from coal fly ash (P-type zeolite, ZP) was prepared and then modified using lanthanum. The structure of the zeolite was characterized by means of SEM, X-ray, TG-DSC, and the like. The characteristics of ZP and lanthanum-modified ZP (LaZP) in the adsorption and desorption of ammonia nitrogen were simultaneously studied, wherein the results show that ZP and LaZP are featured with obvious crystal characteristics, lots of gap structures, and a strong characteristic peak of P-type zeolite shown in the XRD atlas. For the LaZP, the adsorption equilibrium can be carried out in 30 min. The data for the adsorption dynamics to the ammonia nitrogen are in line with the pseudo-second order kinetics equation, and the adsorption isotherme is well fitted to the Langmuir model. The regeneration test shows that the desorption rate of ammonia nitrogen is proportional to the concentration of NaCl when the pH is about 7. The desorption rate of LaZP to the ammonia nitrogen can reach 90% when the concentration of NaCl is 0.4 mol/l, and the desorption rate of ZP is 70%. Compared with ZP, the desorption speed of the LaZP is quicker, the adsorption equilibrium can be carried out in 6 h, and the adsorption equilibrium of ZP can be slowly carried out in 10 h. Moreover, the adsorption and desorption properties of the LaZP are greatly improved.