Papers by Author: Xue Gang Luo

Abstract: In this paper, a kind of new biomass cellular material was prepared by the growth of forage grass such as annual ryegrass, tall fescue, and trefoil in the molding container. In the process of growth, the molding container had been inverted repeatedly. Effect of temperature on the growth of three kind of forage grass was researched by seed germination experiment. The properties of the material were evaluated by TG and universal testing machine. The results showed that 25°C was the optimum growth temperature, and under this condition the germination percentage and germination potential of annual ryegrass, tall fescue, trefoil were respectively 93.67%, 91.67%, 84.33% and 83.00%, 81.67%, 80.67%. The biomass cellular material had good mechanical properties. By changing the addition of seeds, mechanical properties could be adjusted for various end uses.

Abstract: This paper deals with removal of strontium ions from solution by expanding rice husk (ERH) in a fixed-bed column. The absorption characteristics of expanding rice husk for strontium ions were studied systematically. The effects of different column design parameters like bed depth, flow rate and initial strontium concentration on the equilibrium uptake of ERH for strontium ions were investigated. It was found that the equilibrium uptake (q_eq(exp)) of the ERH increased with the increase in initial strontium concentration but decreased with the increase in flow rate and bed depth respectively. Strontium cumulative removals of 2.32 mg/g were obtained under the optimum operational conditions at a flow rate of 10 ml/min and bed depth of 6 cm. XPS analysis indicated that the Sr (II) ion was absorbed on ERH. The adsorption data fitted well with the bed depth service time (BDST) model.

Abstract: This research studied the effects of the water environment on the mechanical, chemical and morphological changes of environmental degradation polyethylene mulching film. The mechanical characteristics of the environmental degradation polyethylene mulching film immersed in water environment or exposed in air declined. The elongation at break retention of the sample immersed in water reached minimum value for 70 days while 40 days for sample exposed in air. FTIR showed new hydroxyl absorption band appeared at 1717cm^-1 after exposed for 60 days. The relative intensity of absorption band of sample exposed in air is higher than sample immersed in water. AFM images showed large fluctuation on the surface after immersed in water or exposed in air for 60days.

Abstract: The sorptive potential of sunflower straw (≤125 μm) for Sr²⁺ from aqueous solution was evaluated. Batch adsorption experiments were carried out as a function of solution pH, adsorbent dosage, Sr²⁺ concentration and contact time. FT-IR spectra and SEM of sunflower straw were employed to explore the functional groups available for the binding of Sr²⁺ and morphology of the adsorbent. Maximum uptake capacity of sunflower straw was 17.48 mg/g occurred at around pH 3-7. The adsorption equilibrium can be achieved within 5 min and kinetic data were fitted well to pseudo-second-order model. The Langmuir and Freundlich models were applied to describe isotherm sorption data. The Langmuir model gave an acceptable fit than Freundlich model.

Abstract: This paper studied the property changes of environmental degradation mulching film and polyethylene mulching film in water environment. The XRD (X-ray diffraction) cures showed that the diffraction angles of environmental degradation mulching film were not changed but intensities and area of diffraction peaks increased after immersion for 60 days; while the diffraction angles and area of diffraction peaks of polyethylene mulching film were same before and after immersion. Cracks and holes appeared in surface of environmental degradation mulching film, but it was still smooth and uniform for the polyethylene mulching film after immersion.

Abstract: At present, in the geological disposal domain of high-level radioactive waste, little is known about microorganisms in deep underground geological environment in our country. This paper introduces some interactions between microbiological and geological disposal of high-level radioactive waste. There is a huge biosphere in the deep underground, mainly held by extremophiles. Microorganisms can influence the waste geological disposal environment in two aspects. On the one hand, the storehouse security will be confronted with serious problems of microorganisms because of their material corrosion capability. The main species of corrosion microorganisms include sulfate reducing bacteria, sulfur-oxidizing bacteria, saprophytic bacteria, iron bacteria and fungi. About research development on interactions between microbiological and geological disposal of high-level radioactive waste in China and abroad, foreign countries started early. Specialized research field has been formed and many achievements has been made by a series of research in Sweden, US, France, Canada, and so on. But relevant study is very few in our country. Therefore, there are special necessity and urgency to carry out this research.

Abstract: A method for extraction of degradable polyethylene (PE) residues in soil was reported in this paper. PE powder (Mw=5000) which was taken as simulated PE residues were evenly mixed with different types of soils. The soil and PE powder mixtures were dissolved in HF:HCl acid mixture (5:2 (v/v)) for 50min at room temperature, followed by sequential washed using water, ethanol, sodium hydroxide and tetrahydrofuran at 45oC. The extraction procedure gave an average recovery rate of 82%. The results show that the soil type had no significant effect on PE recovery rate. The FT-IR spectra and the high temperature gel permeation chromatography (HT-GPC) illustrates that no significant changes in chemical structure and molecular weight and molecular weight distribution of PE after the extraction. The preliminary results obtained indicate that this method can be a new approach in studying the degradation of PE residues in soil.

Abstract: Properties of corn starch dissolved in NaOH/urea aqueous solutions were studied in this research, and NaOH/urea at different ratios in aqueous system was used to treat corn starch (CS). NaOH/urea breaks down the structure of CS, resulting in chemical degradation. After degradation, the change of molecular weight was analyzed by GPC-MALLS. The degraded CS (DS) and native CS(NS) were grafted with acrylic acid and compared in FTIR and both DS and NS were successfully grafted with AA.

Abstract: In this paper, a crosslinked porous lignin beads (PLB) as adsorbent was adopted to adsorb toxic Pb²⁺ and Cd²⁺ ions from aqueous solutions. The pore structure and surface morphology of PLB were characterized by by a variety of techniques. The influences of pH, contact time, initial metal ions concentration, temperatures were investigated. The results showed that the adsorption of both heavy metal ions increases with pH. The adsorption equilibrium data under different temperature can be successfully described by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms. The Langmuir adsorption model showed the best fit to the adsorption data of Cd²⁺ and D-R model fits best to the adsorption data of Pb²⁺. The results obtained also indicated that the adsorption of Cd²⁺ and Pb²⁺ increased with increasing temperature indicating endothermic nature of the adsorption process. The kinetic study showed that Cd²⁺ adsorption followed pseudo-second order rate kinetics and Pb²⁺ adsorption followed pseudo-first order rate kinetics. Cd²⁺ adsorption on PLB was mainly through the chemisorption mechanism (E_D-R between 12.62 kJ•mol^-1 and 16.20 kJ•mol^-1) while physical and chemical absorption coexistence was observed to Pb²⁺ adsorption. Desorption studies revealed that the desorption rate increased with increasing hydrochloric acid concentration and could finally reach 94 % and 85.1 % for Cd²⁺ and Pb²⁺, respectively, by adding 3 mol/L of HCl.

Abstract: Being interested in the development of lignin-containing polymeric materials had been investigated in this paper and the lignin/LDPE-EVA blends compatibilized with LDPE-g-MAH prepared in rheometer were characterized by rheological properties. The experimental results indicated that the maximum, balanced torque and plasticized time were lowest to 53.7N.m-1 and 11.7N.m-1 75s, respectively, with compatibilizer additon of 10 parts. In addtion, mechanical properties, FT-IR, SEM and DSC-TG were measured and the results revealed that the compatibility and miscibility of lignin/LDPE-EVA blends were improved obviously.