基于导向教育的吸附剂合成实验教学设计

金属有机骨架(Metal Organic Frameworks,MOFs)可以作为一种理想前驱体,在惰性氛围中高温热解可以制得在一定程度上继承MOFs部分优点的MOFs衍生碳基材料,从而在吸附领域内有着非常广阔的应用前景。为有效提升吸附剂实验教学效果,培养学生解决复杂工程问题的能力,以环境工程本科生为对象,基于成果导向教育理念(outcome based education,OBE),理论与实践相结合,有效激发学生主观能动性,提升学生严谨的逻辑思维能力,培养其发现问题和解决问题的能力。

合成吸附剂新进展

随着科学技术的发展,吸附分离材料日益广泛的用于制药、环境保护、天然产物的提取精制、去除水中有机物和生物医学工程等领域。众所周知,过去多用硅胶、沸石、活性白土、活性氧化铝、活性炭,骨炭等作为吸附剂。七十年代以来。

用于处理水体油污的合成吸附剂研究进展

油污对水体的污染会产生严重的环境影响,利用合成吸附剂对油污进行吸附处理是最有效的方法之一。介绍了2种最主要的合成吸附剂——活性炭、膨胀石墨、焦炭等碳基材料吸附剂和聚丙烯、聚氨酯、聚苯乙烯等有机合成吸附剂的研究进展,并指出了合成吸附剂研究的发展趋势。

吸附剂在废油资源化技术中的应用和研究进展

吸附处理技术是一种重要的废油资源化处理技术,吸附剂作为该技术的核心,一直是油处理领域研究的热点。随着环境污染问题的日渐严峻、传统吸附剂缺陷的日益凸显以及新型吸附材料的不断涌现,使得替代型吸附剂的开发和应用成为油处理领域迫切需要解决的问题。文章对基于不同材料来源吸附剂在油处理和废油再生过程中的研究和应用情况进行了综述,并对其中的研究进展和研究热点进行了详细介绍。在此基础上,对吸附剂在油处理领域的研究和发展方向进行了展望,并指出处理效果好、环境友好性强、重复使用率高是废油资源化领域吸附剂未来发展的趋势。

响应曲面优化法合成CTMAB-膨润土吸附剂

采用响应曲面优化法(RSM)对CTMAB-膨润土废水处理吸附剂进行合成制备研究。以十六烷基三甲基溴化铵(CTMAB)为有机插层改性剂,通过该法设计得到了有机改性膨润土插层改性的最佳优化条件:CTMAB用量19.5%,反应温度70.5℃,反应时间1.8 h,pH 6.7,DDVP去除率94%,同时得到了合成该吸附剂的二次经验拟合模型(R2=0.9757)。通过验证性实验,发现在模型提供的最优水平下,有机膨润土对DDVP的平均去除率(92.6%)与预测最优值(94%)相吻合,表明所选模型准确、可靠。该方法为改性膨润土吸附剂的合成及其在废水处理和环境修复中的应用提供了依据。

π-Complexation Mesoporous Adsorbents Cu-MCM-48 for Ethylene-Ethane Separation

Copper incorporated MCM-48 molecular sieve adsorbents with different Cu content have been hydrothermally synthesized. The samples have been characterized by various physicochemical methods, including X-ray diffraction （XRD）, nitrogen adsorption （N2） and X-ray photoelectron spectroscopy （XPS）. The results reveal that Cu-MCM-48 with mass fraction of copper up to 10 % can still retain the uniform mesoporous framework of MCM-48. The copper in the framework of MCM-48 was easily auto-reduced to Cu（I） in N2 at high temperature, which did not alter the mesoporous structure of MCM-48. The adsorption equilibrium isotherms of ethylene and ethane on these molecular sieve adsorbents have been measured at 30℃. At 100 kPa, the adsorption capacities of ethylene on 5Cu-MCM-48 and 10Cu-MCM-48 are higher than those on MCM-48. The 10Cu-MCM-48 molecular sieve adsorbent has a higher selective adsorption ratio of ethylene to ethane, the separation factor is 3.8, and the amount of ethylene adsorbed is 11.1 ml·g ^-1.

Synthesis, adsorption and selectivity of inverse emulsion Cd(Ⅱ) imprinted polymers

Inverse emulsion polymerization was employed to synthesize inverse emulsion Cd（Ⅱ） imprinted polymers （IEⅡ P）. The morphology and functional groups of IEⅡP were characterized by SEM,FTIR and TG. Static adsorption experiments and competitive adsorption test were used to evaluate the adsorption ability of IEⅡP. The adsorption capacity of polymers could reach 86.7 mg·g^-1 under the optimal adsorption conditions. The pseudo second order kinetic model and Langmuir isotherm model could be used to analyze the experimental data well. The adsorption process of IEⅡP was chemical adsorption process and monomolecular type. Thermodynamic parameters showed that the adsorption process was endothermic and could occur spontaneously. The selectivity coefficients k of Cd^2＋/v, Cd^2＋/Zn^2＋ and Cd^2＋/Cu^2＋ were 2.4998, 1.2437 and 4.6882, respectively. The proposed method provides a new thought for removing Cd（Ⅱ） in water samples.

Lead Removal from Aqueous Solutions Using Novel Gel Adsorbent Synthesized from Natural Condensed Tannin

Lead has caused serious environmental pollution due to its toxicity, accumulation in food chains and persistence in nature. In this paper, removal of lead from aqueous solutions is investigated using a novel gel adsorbent synthesized from natural condensed tannin. The novel adsorbent performs in aqueous solutions as a weak base with valid basic groups of 1.2mmol·g-1 tannin gel particles and therefore results in the elevation of pH value of aqueous solutions. Even when initial pH is 3.6, final pH at equilibrium can climb up to 6.5 that is above the pH value for Pb(OH)2 precipitation formation and then lead can be removed from wastewater by this so-called surface precipitation. The adsorption isotherm can be expressed by the Langmuir equation and the maximum capacity for adsorption of Pb is up to 92 mg·g-1 (based on dry adsorbent) when initial pH value is 3.6. Hence, the adsorbent does offer favorable properties in lead removal with respect to its high adsorption capacity at low initial pH value, which is advantageous to lead removal from acidic wastewater. A model is put forward to describe the individual adsorption phenomenon of the tannin gel adsorbent.

SYNTHESIS OF SPHERICAL MACROPOROUS ADSORBENT BASED ON UREA-FORMALDEHYDE CONDENSED POLYMER

Spherical macroporous adsorbents with active sites capable of hydrogen bonding adsorption based on urea-formaldehyde condensed polymer were synthesized via reversed suspension polymerization. The properties of the obtained adsorbent were also investigated in detail. The results showed that the water permeability could be improved by adding hydroxyl-containing organic compound moiety into the adsorbent. The specific surface area and average pore diameter of these adsorbents increased while the porosity first increased then decreased with the increase of the amount of the added hydroxyl-containing compound.

Production and Evaluation of Synthetic Carbonated Sand as an Adsorbent Media for Batch Adsorption Process

An attempt was made to improve the adsorption capability of the normal sand to be used as adsorbent for phenol and cadmium This has been done by producing a coated sand media. The coating process was done using emulsion asphalt to convert the normal sand to carbonated sand by using chemical treatment with sulfuric acid. The production process involves mixing of the sand with asphalt and an acid, then subjecting the mix to a heating process. Different mixing ratios, heating temperatures and times （activation times） were tried to obtain the optimum conditions at which the highest removal efficiency is obtained. Three types of acids were tried acetic acid, phosphoric acid and sulfuric acid. It was found that the sulfuric acid requires the lowest activation time, hence selected for the production. The removal efficiency of the produced media was significantly affected by the temperature, mixing ratio and activation heating time. The results show that, the optimum conditions for the production process are 350 , （1：2：3） （Asphalt/acid/sand） and 52 min for temperature, mixing ratio and activation heating time respectively. The final product was tested and found effective as an adsorbent media for phenol and cadmium. The removal efficiencies of these two pollutants in a batch adsorber were found 82.42% and 86.67%, respectively. The X-R diffraction and FTIR spectra tests had proved this media as an adsorbent.

New Synthesized （3-（3,4-dimethoxyphenyl）isoxazole-5- yl） Methanol as Corrosion Inhibitor on Steel in 1 M HCI

The inhibition of corrosion of steel in molar hydrochloric acid solution by new synthesized DMI （（3-（3,4-dimethoxyphenyl）isoxazole-5-yl） methanol） compound is studied by weight loss and electrochemical polarization measurements. The two methods give consistent results. The polarization curves indicate that the DMI compound acts as mixed-type inhibitor. This compound is efficient inhibitor. The inhibition efficiency increases with the increase of inhibitor concentration to reach 96% at 10-3 M for DMI. The temperature effect on the corrosion behavior of steel in 1 M HCI with and without the DMI compound at 10-3 M is studied in the temperature range from 298 to 318 K. The adsorption of inhibitor on the steel surface is found to obey the Frumkin adsorption isotherm model. From the adsorption isotherm, some thermodynamic data for the adsorption process （f, K and △Gads） are calculated and discussed.

Synthesis of a novel functional group-bridged magnetized bentonite adsorbent:Characterization,kinetics,isotherm,thermodynamics and regeneration

A novel magnetic adsorbent was synthesized by magnetizing bentonite by APTES-Fe_3O_4 via a functional groupbridged interaction. The characterization of APTES-Fe_3O_4/bentonite was conducted via transmission electron microscope(TEM), X-ray diffraction(XRD), Fourier transform infrared spectrophotometer(FT-IR), thermal gravimetric analysis(TGA), vibrating sample magnetometer(VSM), zeta potential analysis and Brunner–Emmet–Teller(BET). The APTES-Fe_3O_4/bentonite was assessed as adsorbents for methylene blue(MB) with a high adsorption capacity(91.83 mg·g^(-1)). Factors affecting the adsorption of MB(such as p H, equilibrium time, temperature and initial concentration) were investigated. The adsorption process completely reaches equilibrium after 120 min and the maximum sorption is achieved at p H 8.0. The adsorption trend follows the pseudosecond order kinetics model. The adsorption data gives good fits with Langmuir isotherm model. The parameter factor RLfalls between 0 and 1, indicating the adsorption of MB is favorable. The adsorption process is endothermic with positive ΔH^0 values. The positive values of ΔG^0 confirm the affinity of the adsorbent towards MB, and suggest an increased randomness at the solid–liquid interface during the adsorption process. Regeneration of the saturated adsorbent was easily carried out via gamma-irradiation.

Synthesis of molybdenum disulfide/reduced graphene oxide composites for effective removal of Pb(Ⅱ) from aqueous solutions

In this work, a facile method was adopted to synthesize molybdenum disulfide/reduced graphene oxide （MoS2/rGO） composites through an c-cysteine-assisted hydrothermal technique, The as-prepared MoS2/ rGO composites were firstly applied as adsorbents for efficient elimination of Pb（Ⅱ） ions. Batch adsorption experiments showed that the adsorption of Pb（Ⅱ） on MoS2/rGO followed pseudo-second-order kinetic model well. The adsorption of Pb（Ⅱ） was intensely pH-dependent, ionic strength-dependent at pH 〈 9.0 and ionic strength-independent at pH 〉 9,0, The presence of humic acid （HA） enhanced Pb（Ⅱ） adsorption obviously. The MoS2/rGO composites exhibited excellent adsorption capacity of 384.16 mg g 1 at pH 5.0 and T = 298.15 K, which was superior to MOS2 （279.93 mg g 1） and many other adsorbents. The thermodynamic parameters suggested that the adsorption process of Pb（Ⅱ） on MoS2/rGO composites was spontaneous （zSG＂ 〈 O） and endothermic （△H 〉 0）. The interaction of Pb（Ⅱ） and MoS2] rGO was mainly dominated by electrostatic attraction and surface comple^ation between Pb（Ⅱ） and oxygen-containing functional groups of MoS2]rGO. This work highlighted the application of MoS21rGO as novel and promising materials in the efficient elimination of Pb（Ⅱ） from contaminated water and industrial effluents in environmental pollution management.

Regulatory Action of Charred Gossamer Urocteae on the Functions of Mouse Oral Fibroblasts

Objective： To explore the influence of charred Gossamer urocteae （CGU） on the functions of primary cultured mouse oral fibroblasts and reveal its mechanism in wound healing. Methods： CGU was extracted with different solvents and ethanol extract （EE）, ethyl acetate fraction （EF）, n-butanol fraction （BF） and aqueous fraction （AF） were obtained. The effects of different fractions on the proliferation, matrix metaUoproteinase-2,9 （MMP-2,9） activities, synthesis of collagen and tissue inhibitor of metalloproteinase 1 （TIMP-1） in the mouse oral fibroblasts were determined by MTT, gelatin zymography, chloramine-T method, and enzyme-linked immunosorbent assay （ELISA） respectively. Results： EE, EF and BF at high concentrations could significantly inhibit proliferation of fibroblasts （P〈0.05 or P〈0.01）, and at low concentrations EF and BF could promote proliferation of fibroblasts, and BF and AF could significantly inhibit collagen synthesis （P〈0.05 or P〈0.01）. EE, EF and AF at high concentrations could significantly increase the MMP-9 activity, and BF and AF could significantly inhibit synthesis of TIMP-1. Conclusion： CGU at high concentrations can inhibit the proliferations of fibroblasts and synthesis of collagen, and in healing of wound, CGU at high concentrations possibly has the functions of anti-fibrosis and anti-scar, and the mechanism to promote degradation of collagen is possibly related to the increase in MMP-9 activity and the inhibition of TIMP-1 synthesis.