Papers by Author: Juan Qin Xue

Abstract: According to the structural characteristics of cuprous chloride ions in the wastewater, we use respectively rhodamine-B and 8-hydroxyquinoline as extractant to perform an extraction experimental research for cuprous chloride wastewater. We examine the influence of extraction time, extractant concentration, phase ratio, and pH on the disposal efficiency. We obtain the following observations: The usage of 8-hydroxyquinoline and rhodamine-B as the extractant can extract copper from cuprous chloride wastewater to some extent. Reducing pH of cuprous chloride wastewater solution with concentrated sulfuric acid is not conducive to 8-hydroxyquinoline extraction, which is conducive to rhodamine-B extraction but the effect is not obvious. Increasing temperature is conducive to 8-hydroxyquinoline extraction but not conducive to rhodamine-B.

Abstract: Choosing the basis of 6-311++G (d. p) with chitosan as its model, we use the density functional B3LYP method to optimize the structure and calculate the energy for the chitosan and sulfate. We study the adsorption for the sulfate from different adsorption point (amidogen, hydroxide and carbon-ring) with or without the protonation of chitosan amidogen. Through a comparative analysis of the bond-lengths, bond-angles, charges and binding energies before and after the interaction of chitosan and sulfate, we find that the adsorption of chitosan for sulfate is mainly the adsorption of amidogen after protonation. The adsorption mode is the combination of sulfate with two amidogens after protonation.

Abstract: The separation of cobalt from zinc sulfate solutions by oxidation-precipitation process using peroxy-monosulfuric acid as oxidant has been presented according to the technological conditions of removal of cobalt from zinc electrolyte. After investigating the important parameters governing the separation of cobalt and their effect on the separation process, the optimal parameters of oxidation precipitation of cobalt were determined, the oxidation precipitation percent of cobalt was up to 90% under the conditions. The XRD analysis results of precipitates demonstrated that the precipitate was cobalt hydroxide oxide (CoOOH) in pure cobalt system while the precipitates were cobaltosic oxide (Co₃O₄) and basic zinc sulfate (ZnSO₄(OH)₆^.H₂O) in zinc-cobalt system.

Abstract: The low-cost blue coke industrial by-product, blue coke powder was used as raw material for the production of porous carbons adsorbent by steam activating at temperature of 800°C under the atmosphere of N₂ for 60 minutes. The specific surface area and pore properties of the adsorbent were characterized by using N₂ adsorption-desorption isotherms. Furthermore, the adsorption effects of the adsorbent for ammonia nitrogen in coking wastewater were investigated in terms of particle size, dosage of absorbent and adsorption time. The results show that the specific surface area is 620.94m²/g, the total pore volume is 0.4442cm³/g and the average mesopore size is 4.5808nm, the adsorbent possesses predominant mesoporous structures. In aeration, the removal rate of ammonia nitrogen can reach to 39.5% under the conditions of the ammonia nitrogen concentration of 625mg/L, the dosage of adsorbent 10g/L at the adsorption time of 60 minutes.

Abstract: The QL-03 corrosion inhibition system is obtained by the compounds of quinoline quaternary ammonium salt，mannich base and synergist. The mechanism of QL-03 with HP13Cr in 20%HCl is investigated by potentiodynamic polarization curves, EIS and weight loss measurements. The results show that the inhibition efficiency towards HP13Cr steel is improved greatly and reaches as high as 90% at 90°C, as a mixed corrosion inhibition system. Cumulating the inhibition efficiency from electrochemical results is more reasonable than weight loss result.

Abstract: With phthalic anhydride, urea, metallic salt and ammonium molybdate as raw materials, Cobalt metal phthalocyanines is prepared by solid-phase method, and the cobalt metal phthalocyanine is modified by the shun dl-aspartic acid anhydride. In the homogeneous conditions, the effects of the reaction temperature, the reaction time, phthalocyanine dosage and initiator dosage are studied. The experimental results show that the grafting polymerization products with the highest grafted rate can be prepared under the optimal experimental conditions, which are found to be 60°C for the temperature, 3h for the reaction time, 0.08g for the potassium persulfate and sodium thiosulfate. The product is analyzed by means of IR, the results show that the chitosan is grafted successfully, and the reaction may occurs on the amino and the hydroxyl of chitosan.

Abstract: In this study, chitosan was modified by acrylamide and acrylonitrile when NaHSO₃-K₂S₂O₈ as initiator under N₂. Chitosan-acrylamide-acrylonitrile ternary graft copolymer was synthesized on the use of radical polymerization mechanism. The optimal experimental conditions for the preparation are obtained by orthogonal experiments: the reaction temperature 65°C, the reaction time 6.5h, the concentration of NaHSO₃ 3mmol/L, the concentration of K₂S₂O₈ 4.5mmol/L, and the ratio of m(chitosan):m(acrylamide):m(acrylonitrile) was 1:6:4. Under such conditions, the average graft ratio and the graft efficiency could achieve 852.455% and 85.260% respectively. Chitosan and chitosan-acrylamide-acrylonitrile ternary graft copolymer were then characterized by means of XRD and SEM, and the graft mechanism was explored preliminary as well. The results showed that chitosan was modified successfully by graft polymerization, and the surface property and the strength of the product were also improved obviously.

Abstract: Investigated the sorption kinetics of methylene blue on spherical chitosan resin. Studied the influences of ionic strength, pH， initial concentration on the adsorption process. The adsorption of methylene blue increases with the decreasing ionic strength and the increasing pH and the initial concentration of the system. Furthermore, the adsorption process correspondes with Lagergren pseudo-second kinetic equation and the finess (R²) of the model was above 0.99.

Abstract: Formaldehyde cross-linked chitosan was used to adsorb sulfate ions from aqueous solution in this study. Batch experiments were conducted to investigate the conditions of the adsorption, the isotherms and kinetics of the adsorption. The optimized conditions of adsorption were as follows: the adsorbent dosage was 0.5g, the equilibrium time was 240min, the initial concentration of sulfate ions was 153.3mg/L, the temperature was 50°Cand the value of pH was 2.2. The maximum adsorption capacity came up to 14.7 mg/g with the adsorption efficiency got to 95.7%. The equilibrium data fitted Langmuir isothermal model well. In addition, the adsorption process could be explained by the second-order kinetic model, and the chemisorption was the limit step for adsorption velocity.

Abstract: The density functional theory (DFT) calculations explored the structural optimization and the frequency of N-carboxymethyl chitosan (N-CMCS) and O-carboxymethyl chitosan (O-CMCS). For the isomers, the calculations comparatively were performed. The charge distribution and frontier molecular orbit were analyzed by using the natural bond orbital (NBO) method. The results showed: the two rotational isomers a and b can stably exist, with the stability order a>b; N-carboxymethyl chitosan reaction active sites are concentrated in -OH and -NHCH2COOH, while O-carboxymethyl chitosan reaction active sites are concentrated in -NH2 and -CH2COOH; The water-soluble mechanism of carboxymethyl chitosan was investigated deeply, on the one hand, the presence of carboxymethyl of carboxymethyl chitosan had a tendency to ionize H+, on the other hand the carboxymethyl increased the distance and weakened the hydrogen bonds between molecules, even though Einstein shift H-bond is formed in the carboxymethyl chitosan molecules.