纳米腐殖酸动态吸附废水中镉离子及其洗脱特性

在静态法研究纳米腐殖酸吸附模拟含镉废水基础上搭建考察模拟含镉废水中镉离子在吸附剂上动态吸附及洗脱特性的吸附柱实验装置,考察镉离子溶液浓度、吸附(脱附)温度、共存离子和进料流速对穿透吸附量和饱和吸附量的影响,运用Thomas模型研究了纳米腐殖酸柱吸附过程动力学机理,测定了再生后纳米腐殖酸的穿透吸附量和饱和吸附量,结果表明:初始镉离子浓度150 mg·L^-1和流速10 ml·min^-1下,其饱和吸附量分别为426.3 mg·g^-1和405.5 mg·g^-1;Thomas模型所得饱和吸附量q_em分别为364.1、436.1和441.9 mg·g^-1;洗脱峰镉离子浓度分别为3.3、12.0和22.0 g·L^-1;共存离子SO₄^2-浓度增加,纳米腐殖酸对镉离子的穿透吸附量和饱和吸附量降低;吸附和脱附均可常温工况进行。经30次吸附和再生后,穿透吸附量和饱和吸附量无明显降低。用红外光谱仪(FT-IR)、扫描电镜(SEM)及X射线能谱仪(EDS)对纳米腐殖酸吸附再生前、后性能进行表征,结果表明:纳米腐殖酸物化性能稳定,形貌基本无变化,尺度发生一定程度减小,表面及内部的氨基、羟基等对吸附镉离子均发挥有效作用,该材料可满足重复使用。     

钙基吸附剂中纳米CaO与CO_2反应动力学模型的改进

纳米Ca O基吸附剂的吸附容量经历最初碳化和再生反应循环过程衰减后趋于稳定,研究了经过多次循环预处理后稳定的钙基吸附剂中纳米Ca O与CO2反应动力学。钙基CO2吸附剂预处理条件为碳化反应温度为600℃,再生反应温度为800℃循环42次。采用热重分析仪,在吸附温度550~630℃,CO2分压0.01~0.02 MPa条件下,测定预处理后得到的吸附剂中纳米Ca O与CO2的反应速率。通过优化气-固离子反应吸附模型的参数,拟合实验数据得到改进的反应动力学方程,求得反应活化能为77.7 k J?mol?1,约为新鲜吸附剂第一次吸附反应活化能的2.5倍。方程平均相对误差仅为6.4%。得到的改进动力学方程更真实反映吸附剂在稳定循环使用条件下的纳米Ca O与CO2反应动力学特性。     

MnO2/NaY复合材料的制备及其对SO2脱除性能

以NaY分子筛为载体，MnO₂为活性组分，采用沉淀法制备MnO₂/NaY复合脱硫材料；通过X射线衍射（XRD）、扫描电子显微镜（SEM）、氮气吸附脱附法（N₂-吸附脱附）、X射线光电子能谱（XPS）、热重分析（TG）等手段进行材料的物理化学结构表征；使用容量法装置测试复合材料的脱硫性能；考察MnO₂不同负载量及不同反应温度对MnO₂/NaY复合材料脱硫性能的影响。结果表明：MnO₂/NaY复合材料的孔容越大，其脱硫性能越好；多孔珊瑚状MnO₂脱硫性能优于棒状MnO₂；随着MnO₂负载量及反应温度的增加，MnO₂/NaY的脱硫性能先增加后降低，MnO₂/NaY-41%在400℃时的脱硫性能最好，第1h脱硫量达到114.56mg {{}_{\mathrm{S}\mathrm{O}}}_{{}_2} /g_材料；500℃时复合材料脱硫性能下降，是由于脱硫反应过程中MnO₂分解生成Mn₃O₄；MnO₂/NaY比纯MnO₂拥有更好的脱硫性能，反应温度为300℃和400℃时，MnO₂/NaY-41%较纯MnO₂的第1h脱硫量分别提高28.3%和56.1%。MnO₂/NaY-41%复合材料在中低温下的高效脱硫性能有望应用于船舶尾气的深度脱硫。     

氮修饰木质素基超交联聚合物的制备及其放射性碘捕获

开发高效、低成本的放射性碘捕获材料对核能的安全利用和核废料处理具有重要意义。本文针对目前碘捕获材料吸附容量低、成本高等问题,以含有羟基、羧基等活性位点的木质素为基础原料,N,N-亚甲基双丙烯酰胺（MBA）为氮源,对氯甲基苯乙烯（VBC）为功能单体,通过自由基聚合接枝与Friedel-Crafts烷基化两步反应,原位构筑一系列氮修饰木质素基超交联聚合物（NLHCPs）,其比表面积最高可达715.8m²/g,且有较高的氮含量（3.95%~4.48%,原子分数）。分别研究了NLHCPs对碘蒸气和碘正己烷溶液的吸附性能,结果表明NLHCP-2的碘蒸气吸附容量最高,可达2.5g/g,吸附作用主要为化学吸附,碘分子在聚合物表面转变成聚碘阴离子的形式。而其对正己烷中碘的吸附等温线更符合Freundlich模型,吸附最大平衡容量可达230.8mg/g,动力学拟合表明其吸附速率主要受扩散过程控制。吸附碘蒸气后的材料,在乙醇中可快速脱附,具有良好循环使用性能。     

Cardanol: A New Dispersant for Alumina in Toluene

Cardanol, which is a naturally occurring C₁₅ unsaturated aliphatic chain-substituted phenol derived from cashew nut shell liquid, was used as a dispersant for alumina in toluene. Adsorption data, along with the results of sedimentation studies, green density, and slurry viscosity (as a function of dispersant concentration), suggest that cardanol adsorption initially proceeded through surface coverage by a phenolic group that lies flat on the surface and that the best powder dispersion occurred at surface saturation by more closely packed end-on adsorbed cardanol molecules. The alkyl-chain unsaturation significantly contributed to dispersion, such that the saturation by hydrogenation led to an increase in the slurry viscosity by a factor of ∼2.5. Concentrated slurries generally showed shear-thinning flow behavior, and the measured viscosity of a highly concentrated (53 vol%) slurry was <1 Pa·s at a shear rate of 93 s⁻¹.     

丙烯酸系高吸油树脂的合成

以丙烯酸丁酯和α-甲基丙烯酸十二酯为主单体 ,二甲基丙烯酸乙二醇酯、邻苯二甲酸二烯丙酯和二甲基丙烯酸 1 ,4-丁二醇酯为交联剂合成高吸油树脂 ,研究了第三单体甲基丙烯酸甲酯交联剂分子结构对树脂吸油性能的影响。     

氯化钙/膨胀石墨混合吸附剂导热性能研究

研究出具有良好的导热性能的吸附剂是吸附制冷的关键。利用耐驰LFA447导热仪测试了不同质量配比（氯化钙与膨胀石墨的质量比）和不同固化压力下氯化钙—膨胀石墨固化混合吸附剂的导热性能。实验结果表明：在一定范围内,在相同的质量比下随着固化压力的增大,导热系数不断增大;在相同的固化压力下随着氯化钙—膨胀石墨质量比的增大导热系数不断减小。在测试的所有样品中,当固化压力为1.7KN,氯化钙—膨胀石墨的质量比为2：1时,混合吸附剂的导热性能比较好,导热系数达到2.7 W/(m?K)。     

Sorptive Removal of Cesium-137 and Strontium-90 from Water by Unconventional Sorbents

It has been shown that coal fly ash is a good adsorbent for both radionuclides of ¹³⁷Cs and ⁹⁰Sr. Radiocesium adsorption is maximal around the neutral region whereas radiostrontium adsorption increases with pH, especially above pH 8. Cesium retention sharply drops with ionic strength while strontium adsorption increases sharply and steadily at low and moderate concentrations of the inert electrolyte, respectively. The suggested mechanisms of radionuclide retention by fly ash is specific adsorption of Cs⁺ and irreversible ion-exchange uptake of Sr²⁺. The isotherm of adsorption is a Langmuir approximation of the B.E.T. multi-layered sorption. Acid pretreatment of fly ash, though not increasing radionuclide sorption capacity, may be useful in preventing the leach-out of other contaminants from the sorbent into water during the adsorption process.     

A robust quasi-superhydrophobic ceria coating prepared using air-plasma spraying

Hydrophobic coatings that could survive in harsh environment have a wide range of applications from industry to houseware. However, the state-of-the-art polymer-based coatings cannot meet such requirements due to their low melting point and poor wear resistance. In this study, we reported a plasma sprayed ceramic coating made of ceria with exceptional hydrophobicity, high-temperature stability, and good wear resistance. The coating exhibited a water contact angle (WCA) up to 139°, due to the intrinsic hydrophobicity of ceria and unique surface morphology produced by plasma spraying. The WCA only slightly decreased to 131° after annealing at 773 K. In addition, the polished coating (WCA ~ 116°) was still more hydrophobic than the sintered bulk specimen (WCA ~ 95°) with the same composition and roughness, which can be attributed to the surface chemistry change induced by Ar⁺ ion bombing by plasma. It is believed that such robust hydrophobic coating should have great potential in engineering application.     

Eudragit E100/poly(ethylene oxide) electrospun fibers for DNA removal from aqueous solution

The development of new strategies for production of low-cost deoxyribonucleic acid (DNA) adsorbents based on electrospun fibers of block copolymers [Eudragit E-100/poly(ethylene oxide) (PEO)] is a promising way for fast retrieval of free of degradation double-stranded DNA chains from aqueous solution. The adsorption takes place through electrostatic interaction between DNA and oppositely charged electrospun fibers that provide high surface area for DNA adsorption. The adsorption capacity observed for electrospun fibers of Eudragit E100/PEO (considering as target molecules the salmon sperm DNA) was in order of 44.31 mg g⁻¹, following the Langmuir model in a typical adsorption at solid/liquid interface (pseudo-second-order model), that characterizes the electrospun fibers as promising templates for removal of biologic components and further use in molecular biology techniques, as DNA amplification by polymerase chain reaction. The reuse and integrity of membranes after long period of adsorption were tested, confirming the potential of material as adsorbent. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47479.