Papers by Keyword: Adsorption Property

Abstract: The aim of the study was to make known of the adsorption property of several materials which would be the component of a type of green sorption media blends having advantages in cost, availability, permeability, environmental benefit, and strong removal efficiency to the nutrient from surface runoff. The media blends were suitable for the substrate in the retention ponds, bio-swales, rainwater garden, river side pond, and helpful to control the non-pointed nutrient pollution in the surface runoff. The sand-loam, sawdust, tire crumb, limestone, and ceramic sand were selected to study the adsorption property of ammonia, nitrates, total phosphorus (TP) in the static adsorption test. Langmuir and Freundlich isotherm were used to fit the adsorption property. The experimental results showed that it was the combined action of physical and chemical adsorption to the removal of ammonia, nitrate, TP by the five kinds of adsorption materials. The adsorption property to the ammonia of the five materials were sand-loam>sawdust>ceramic sand>limestone>tire crumb, to the nitrate were sand-loam>tire crumb>sawdust>ceramic sand>limestone, to the TP were tire crumb>sand-loam>ceramic sand> limestone>sawdust. The sand-loam and sawdust were the prior materials to remove nitrogen, while the tire crumb had the great advantages to remove phosphorus.

Abstract: Under the effect of an adjustable magnetic field (0-0.6T), porous silica gel was synthesized via sol-gel process by phase separation method to investigate the effect of magnetic field on the formation time of porous silica gel and the influence of porous silica gel synthesized under the induction of magnetic field (m-SiO₂) on Pb²⁺ adsorption property. The findings of this study show that the reaction rate can be increased and the gelation time shortened under the effect of magnetic field. Within the range of intensity of the magnetic field in this study, the 0.25T magnetic field affects the porous silica gel most significantly and can reduce the gelation time from 120min to 90min; the Pb²⁺ adsorption property of m-SiO₂ is better than that of ordinary silica gel (SiO₂); under the condition that the solid-to-liquid ratio and the pH value change, the Pb²⁺ equilibrium adsorption rate and equilibrium absorption capacity of silica gel synthesized with the 0.25T magnetic field, compared with ordinary silica gel (SiO₂), can averagely increase by 11.32% and 11.20mg/g, respectively.

Abstract: Mesopore activated carbons were prepared using hemp stem as feedstock by air-phosphoric acid activation method. The crystallite size of hemp stem-based mesoporous carbon is small, and its pores is larger. The phosphoric acid solution concentration has a signification effect on pore structure and adsorption property of mesopore activated carbons from hemp stem. The mesopore activated carbon attained at phosphoric acid solution concentration of 50% exhibits a maximum BET(Brunauer Emmett and Teller) specific surface area of 1351m²/g, total pore volume of 1.21 cm³/ g, mesopore pore volume of 0.90 cm³/ g and a mesopore fraction of 74.4%. And the resulting carbon has smaller crystal size, developed pore structure, wider pore size distribution.

Abstract: Mesoporous carbon material CMK-3 was successfully prepared by using mesoporous silica material SBA-15 as hard template and sucrose as carbon source through a nanocasting method. In order to improve the hydrophilic properties of the carbon materials, a large amount of carboxylic functional groups have been introduced upon the surface of carbon materials by oxidative treatment. Transmission electron microscopy (TEM) exhibit highly ordered mesostructure with 2-D hexagonal symmetry of our sample. An absorption assigned to the -COOH groups is clearly visible in Infrared spectra, suggesting the presence of carboxylic functional groups. Rhodamine B (Rh B) was selected as a model for determining the adsorption activity of the obtained material. This material exhibited a high adsorption capacity, and an extremely rapid adsorption rate.

Abstract: With the enhancement of environmental awareness and the development of coking technology, large domestic coking plant With the enhancement of environmental awareness and the development of coking technology, large domestic coking plant With the enhancement of environmental awareness and the development of coking technology, large domestic coking plant will use CDQ technology to deal with Coke. So a great number of coke powder will be produced in coking enterprises every day. This paper use coke power, the waste of coking enterprises, as raw material to produce activated carbon with good adsorption property by chemical activation. The surface chemical composition and surface area of the activated carbon were investigated. The effects of activation conditions on the characteristics of the activation carbons were studied.As a result, activated carbon with an iodine adsorption capacity of 1020mg/g, a methylene blue adsorption capacity of 365 mg/g and a specific surface area of 1600 m2/g was obtained. These adsorption capacities were almost the same as ordinary activated carbon on the market.

Abstract: Various jute-based activated carbon fibers were prepared by using jute fibers as raw materials and phosphoric acid as activating agent. The effects of three main factors such as concentration of activating agent, activation temperature and activation time on the yield and adsorptive properties of active carbon fibers were investigated via orthogonal experiments. The surface physical morphology of jute-based activated carbon fiber was also observed by using Scanning Electron Microscope. Results showed that the optimum conditions were phosphoric acid concentration of 4 mol/L, activation temperature of 600 °C and activation time of 1h. The yield, iodine number and amount of methylene blue adsorption of the active carbon fiber prepared under optimum conditions were 37.99 %, 1208.87 mg/g and 374.65 mg/g, respectively.

Abstract: The synthesis of a novel chitosan (CTS) derivative bearing β-cyclodextrin (β-CD) was studied, which was divided into two steps. The first step was the preparation of carboxymethyl-β-CD, then it was acyl chlorided. The second step was that β-CD was grafted onto the CTS skeleton by the reaction of acidamide. Its adsorption property on Pb²⁺ was investigated. The factors that influence on the effect were discussed, including adsorption time, pH value, and temperature. The results show that its adsorption content is superior to that of the unmodified CTS. And the adsorption content (Q_max) is 246 mg.g^-1 when the temperature is 35°C, pH is between 3.0~4.0 and adsorption time is 6 h.

Abstract: Sewage sludge incineration residue was obtained from a sewage treatment plant in Guangzhou and used as a low-cost sorbent for removing Ni²⁺ from wastewaters. The adsorption effectiveness and their factors of Ni²⁺ in aqueous solutions were simulated detailed using the adsorbents of the sludge incineration residue. The simulation contents and the factors included the adsorption time, the pH of solution and the dosage of adsorbents and so on. The results showed that at room temperature, the adsorption equilibrium of Ni²⁺ can be achieved in 6h and the best pH value of the solution was about 7.0. The removal rates of Ni²⁺ were increased with the adsorbent concentration increasing and the optimal concentration of adsorbent was 10g/L with the initial concentration of Ni²⁺ less than 30mg/L.At the best adsorption conditions, the removal rate of Ni²⁺ reached more than 70%.

Abstract: To explore a novel sensor to detect the presence of nitrogen dioxide (NO2), we investigate reactivity of boron-doped (B-doped) single-walled (8,0) silicon carbide nanotube (SiCNT) with NO2. Based on density functional theory, the structure and electronic properties of the B-doped SiCNT with and without the adsorption of NO2 molecule have been calculated. Results show that a stable adsorption between the nanotube and the gas molecule is formed and the conductivity of the SiCNT is improved obviously. B-doped SiCNT is expected to be a potential candidate for detecting the presence of NO2.

Abstract: A novel chelating resin, crosslinking polystyrene-supported glucosamine (PS-GA), was prepared and its static adsorption properties for Ag(Ⅰ) were studied. The results indicated that this resin had excellent adsorption capacity for Ag(Ⅰ). The adsorption dynamics indicated that adsorption was controlled by the liquid film diffusion and the apparent activation energy Ea was 11.83 kJ/mol. Both Langmuir model and Freundlich model could describe the adsorption isothermal process of Ag(Ⅰ), and ∆G, ∆H, ∆S values were calculated. Increasing the temperature was beneficial to adsorption. The chelating resin can be easily regenerated by 2% thiourea in 0.1 mol/L HNO3 with higher effectiveness. Five adsorption–desorption cycles demonstrated that this resin was suitable for repeated use without considerable change in adsorption capacity.