氧化树脂对水溶液中2,4-二氯苯酚的吸附特征

用H2O2或HNO3氧化超高交联吸附树脂NDA150的方法制备了新型吸附树脂ZH-07和ZH-08,并通过元素分析和比表面积及孔径分布仪进行了表征。同时以NDA150作为参照,研究了它们对不同温度下水溶液中2,4-二氯苯酚的静态吸附和脱附特征,并对其吸附机理进行了探讨。结果表明,ZH-07和ZH-08对2,4-二氯苯酚具有和NDA150相近或更优的吸附容量,对水溶液中2,4-二氯苯酚的吸附过程存在化学吸附作用,也可以提高它们对水溶液中2,4,-二氯苯酚的吸附容量。     

巯基修饰的超高交联树脂对酚类化合物的吸附

对超高交联聚苯乙烯树脂进行巯基修饰,对比大孔吸附树脂(Amberlite XAD-4)对苯酚、对甲苯酚、对氯苯酚、对硝基苯酚在水溶液中进行吸附研究。经过巯基修饰的超高交联聚苯乙烯树脂(JN-8)具有亲水性高、对酚类化合物吸附容量大的优点,该树脂可望在高浓度含酚废水治理中得到应用。     

乙酰苯胺和水杨酸修饰的两种吸附树脂对对氯苯酚的吸附行为

分别用乙酰苯胺、水杨酸化学修饰氯甲基化低交联大孔苯乙烯-二乙烯苯聚合物,合成超高交联吸附树脂FZH03、FZH04。与Amberlite XAD-4对照,研究了这两种树脂在不同温度下对水溶液中对氯苯酚的静态吸附和动态吸附行为。结果表明,两种树脂的等温吸附数据可被Langmuir和Freundlich等温吸附方程很好地进行拟合,对对氯苯酚的吸附量明显高于XAD-4,是焓推动的吸附过程,对对氯苯酚吸附动力学均符合一级动力学方程,有两个独立的动力学过程,颗粒内扩散是该吸附过程的速控步骤。     

醚键型超高交联吸附树脂对苯胺和苯酚的吸附性能

以苯乙醚和氯甲醚为原料,一步合成了含氧的亲水性超高交联吸附树脂OCHR-2。树脂的比表面积为352.45 m2/g,含氧量为11.91%。用树脂Amberlite XAD-4为对比对象,研究了两种树脂对水中苯酚及苯胺的吸附性能。结果表明,相同条件下,树脂OCHR-2对苯胺的吸附量可达XAD-4的2.25倍,对苯酚的吸附量最高为XAD-4的3倍。树脂对苯胺和苯酚的吸附符合Freundlich和Langmuir吸附等温线;树脂OCHR-2对苯胺的吸附为吸热过程,对苯酚的吸附为放热过程。树脂经过5次再生利用后,吸附量没有发生明显的变化,说明树脂具有很好的可再生能力;树脂OCHR-2有望在酚类和胺类废水资源化治理中得到实际应用。     

乙酰苯胺修饰的吸附树脂对对甲苯胺的吸附机理研究

合成了一种用乙酰苯胺修饰的新型超高交联吸附树脂ZH-05,并用Amberlite XAD-4作对照,比较了它们对水溶液中对甲苯胺的静态吸附和脱附行为。结果表明:经过乙酰苯胺修饰的吸附树脂ZH-05在一定温度下对对甲苯胺的吸附过程中存在化学吸附,ZH-05对对甲苯胺的吸附能力明显强于AmberliteXAD-4,两种树脂对甲苯胺的吸附均符合Freundlich方程。     

分子印迹氨基功能化纳米Fe_3O_4高分子磁性复合材料的合成及其对海水中2,4,6-三氯苯酚的吸附性能

为了实现海水中2,4,6-三氯苯酚(2,4,6-TCP)的选择性吸附和去除,采用超声协助悬浮聚合法以2,4,6-三氯苯酚为模板制备了分子印迹氨基功能化纳米Fe3O4高分子磁性复合材料(nFe3O4@MIPNH2-polymer)。通过元素分析(EA)、X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱分析、透射电子显微镜(TEM)、振动样品磁强计(VSM)等手段对nFe3O4@MIPNH2-polymer的组成、结构、形貌、磁性等进行表征,并研究了其应用于吸附和去除海水中2,4,6-三氯苯酚(2,4,6-TCP)污染物的性能。结果表明:合成的nFe3O4@MIPNH2-polymer平均粒径约为800nm,饱和磁化强度为32.6emu·g-1;水溶液中2,4,6-TCP的饱和吸附量为105.26mg·g-1,高于非分子印迹氨基功能化纳米Fe3O4高分子磁性复合材料(nFe3O4@NH2-polymer)的饱和吸附量(76.92mg·g-1),nFe3O4@MIPNH2-polymer对2,4,6-TCP的等温吸附线大体符合Langmuir模型。吸附热力学研究表明,nFe3O4@MIPNH2-polymer对2,4,6-TCP的吸附过程是自发的吸热熵增过程;吸附过程可在5min内达到平衡,动力学数据和准二级动力学模型符合较好;其吸附过程去除2,4,6-TCP的活化能为78.0kJ·mol-1。海水中的共存物质对吸附2,4,6-TCP几乎无干扰,nFe3O4@MIPNH2-polymer经洗脱后可以循环使用5次以上。nFe3O4@MIPNH2-polymer能高选择性地有效去除海水中的2,4,6-TCP。     

含酚羟基吸附树脂的研究进展

含酚羟基的吸附树脂不仅对金属离子具有较好的螯合性能,也对有机分子具有很好的吸附性能。含酚羟基的吸附树脂可以由酚类化合物与醛反应制备,也可以将酚羟基引入到聚合物表面制备酚羟基修饰的吸附树脂。综述了由苯酚及衍生物、植物多酚,如单宁、木质素、漆酚为原料制备含酚羟基吸附树脂的研究进展。     

光氯化-烷基化两步法制备超高交联树脂及对苯酚的吸附性能

通过对二甲苯侧链光氯化产物(CP)与苯(BE)的Friede-l Crafts烷基化聚合反应制备比表面积高达905m2/g的超高交联吸附树脂(CP-BE)材料,并用红外光谱(FT-IR)、元素分析(EA)及比表面积(BET)对其结构进行表征。以XDC-BE和市售Amberlite XAD-4为参照,在不同温度下,测试了三种吸附树脂对水溶液中苯酚的吸附性能,结果表明,CP-BE和XDC-BE树脂对苯酚的吸附量分别高达171 mg/g和143 mg/g,远高于国内外用于酚类吸附的Amberlite XAD-4树脂,有望在酚类废水资源化治理中得到实际应用。     

邻羧基苯甲酰基修饰的吸附树脂对水中2-萘酚的吸附

采用邻羧基苯甲酰基修饰的吸附树脂FZH5,以Amberlite XAD-4作为参照,探讨了对水溶液中2-萘酚的吸附热力学和吸附动力学。分别用Langmuir等温方程和Freundlich等温方程对吸附等温线进行拟合,并采用动力学准一级和二级方程对两种树脂进行了动态吸附拟合。结果表明,经过修饰的FZH5对水中2-萘酚的吸附效率高于Amberlite XAD-4,对2-萘酚的吸附过程在温度较高时化学吸附为主导,吸附速率主要受控于颗粒内扩散过程。     

AgBr-WO3/GO载流子转移增强及其可见光降解2,4,6-三氯苯酚

采用原位合成法制备AgBr-WO3/GO复合可见光催化剂,制备的AgBr-WO3/GO表现出比WO3和WO3/GO更强的可见光吸收.AgBr-WO3/GO的表观光催化降解2,4,6-三氯苯酚的速率常数k为0.677 h-1.可见光光照4 h后,2,4,6-三氯苯酚的去除率达到94％以上,明显优于WO3和WO3/GO.实...     

弱酸性吸附树脂对水溶液中咪唑烷的吸附

利用超高交联吸附树脂NDA150和NDA99对不同温度下水中咪唑烷的静态吸附实验,研究了NDA99和NDA150对咪唑烷的吸附情况,提出了对树脂表面修饰的设想,并进行了静态吸附和实际废水的动态吸附验证,结果表明,具有弱酸性的超高交联吸附树脂对咪唑烷具有较好的吸附选择性。     

[HMIM]BF_4对盐酸中A3和HP13Cr钢的缓蚀行为

为了减少钢铁冶金酸洗过程中酸液对不锈钢或碳钢的过腐蚀,得到高效的新型缓蚀剂材料,利用失重法、电化学法及扫描电子显微镜(SEM)等研究了不同浓度离子液体[HMIM]BF_4对HP13Cr不锈钢以及A3碳钢在1 mol/L盐酸溶液中的缓蚀特性和吸附行为。失重试验得出,试样在1 mol/L盐酸溶液中的腐蚀速率随离子液体添加浓度的增大而减小,即离子液体缓蚀效率随其浓度增加而增大;SEM结果显示,盐酸溶液中离子液体的添加对不锈钢HP13Cr以及碳钢A3均能起到显著的保护作用。电化学测试表明,该离子液体对这2种钢材的缓蚀作用均属于混合型抑制,但阳极抑制作用表现更强。离子液体对金属的防护作用与其在金属表面的吸附行为有关;[HMIM]BF_4在2种钢材表面的吸附行为符合Langmuir吸附等温线,兼具物理、化学吸附特性,热力学参量表明吸附过程为自发、吸热的熵增过程。相比于双咪唑季铵盐,[HMIM]BF_4离子液体缓蚀剂保护性能更优异,而且对于A3碳钢更为有效。     

Preparation of an aminated macroreticular resin adsorbent and its adsorption of p-nitrophenol from water

A chloromethylated styrene-divinylbenzene copolymer was post-cross-linked through Friedel-Crafts reaction to get a macroreticular resin adsorbent NA-01, and then chemically modified by dimethylamine to obtain an aminated adsorbent NA-01A. Batch adsorption runs of p-nitrophenol from aqueous solution onto adsorbent NA-01A were conducted to evaluate the effect of amino group on adsorption. The adsorption capacity of p-nitrophenol on NA-01A increased noticeably by comparison with the mother adsorbent. A linear relationship was observed between the adsorption capacity of NA-01A caused by amination and the equilibrium concentration of p-nitrophenol in aqueous solution, which can be reasonably elucidated by a modified isotherm equation based on the Freundlich model. The breakthrough curves on both adsorbents were experimentally determined and also predicted by the mathematic model based on the non-linear wave propagation theory and the corresponding isotherm model. The model based on the Freundlich model gave a good prediction of the breakthrough curve on NA-01, but a deviation occurred for NA-01A when C/C0 less than 0.3. However, another model based on the modified isotherm equation provided a better prediction for the breakthrough curves on NA-01A.     

Investigation of phase purity of faujasite-type Y zeolite

Phase purity of Y zeolite has been studied by X-ray powder diffraction analysis and by measurement of equilibrium adsorption capacity. X-ray powder pattern of Y zeolite does not comprise the diffraction with d₄₂₂ = 0.5 nm, reported by previous authors. Pure Y and KS01 zeolite were prepared, and it was shown that the occurrence of the above-mentioned diffraction is due to the presence of KS01 zeolite in the investigated samples. Heating the KS01 zeolite to 300, 400, 500, and 650°C leads to amorphization of the structure with gradual loss of adsorption capacity, while the crystal structure and adsorption capacity of the Y zeolite remains preserved. Both methods have been used for identification of KS01 admixture in Y zeolite.     

Adsorption and separation of carbon dioxide and methane on carbonaceous adsorbents

Adsorption and separation of carbon dioxide and methane on different carbonaceous adsorbents were analyzed and compared. Coconut shell-based activated carbon has the highest adsorption capacity for two gases. Sips model describes the adsorption isotherms best. The separation factor on coconut shell-based activated carbon is the highest under various conditions, reaching about 3.8. The adsorption capacity of the two gases is closely related to the specific surface area and micropore volume of the adsorbent. The adsorbed amount of each component in the mixture is less than that of the pure component under the same condition, indicating that there is a competition in the adsorption process. The total adsorbed amount of the two gases decreases as the proportion of carbon dioxide decreases, implying that the adsorption process is dominated by carbon dioxide adsorption. Additionally, the separation factor decreases with increasing temperature. Understanding the adsorption behaviors of pure and binary carbon dioxide and methane is important in treating biomass gas using carbonaceous adsorbents.     

Adsorption of bisphenol-A from aqueous solution onto minerals and carbon adsorbents

The adsorption behaviors of bisphenol-A, which has been listed as one of endocrine disrupting chemicals, from aqueous solution onto four minerals including andesite, diatomaceous earth, titanium dioxide, and activated bleaching earth, and two activated carbons with coconut-based and coal-based virgins were examined in this work. Based on the adsorption results at the specified conditions, the adsorption capacities of activated carbons are significantly larger than those of mineral adsorbents, implying that the former is effective for removal of the highly hydrophobic adsorbate from the aqueous solution because of its high surface area and low surface polarity. The adsorption capacities of bisphenol-A onto these mineral adsorbents with different pore properties are almost similar in magnitude mainly due to the weakly electrostatic interaction between the mineral surface with negative charge and the target adsorbate with hydrophobic nature. Further, a simplified kinetic model, pseudo-second-order, was tested to investigate the adsorption behaviors of bisphenol-A onto the two common activated carbons at different solution conditions. It was found that the adsorption process could be well described with the pseudo-second-order model. The kinetic parameters of the model obtained in the present work are in line with the pore properties of the two adsorbents.     

不同小分子渗透物在聚酰亚胺膜中的吸附特性

用动态吸附装置分别测定了不同小分子渗透物在两种不同结构的聚酰亚胺(PI)膜中的吸附行为,计算了反常扩散指数(dW);通过分析反常扩散指数比较了不同小分子在聚酰亚胺膜中的吸附特性.研究结果表明:不同溶剂水、甲醇、乙醇、异丙醇分子在PI膜中的扩散速度顺序为:水>甲醇>乙醇>异丙醇,PI膜的反常扩散指数随以上顺序逐渐增大.     

Forces between colloidal droplets in the presence of a weak polyelectrolyte

In this paper, we present the results on the forces between individual colloidal liquid droplets in the presence of a weak polyelectrolyte, poly(acrylic acid), using magnetic chaining technique. The effect of the repulsive forces have been investigated under different experimental conditions such as polyelectrolyte concentration, adsorption time, salt concentration etc. At a PAA concentration of 0·01% (weight), a long range repulsive force profile is observed due to the adsorption of polyelectrolyte on the droplet, without any irreversible aggregates even at very small inter-droplet spacing. Above a concentration of 0·01 wt% of PAA, formation of irreversible chaining of droplets is observed at short inter-droplet separations due to polyelectrolyte bridging. The onset of binding is also independently confirmed by microscopic observation. Compared to the slow adsorption on mica surfaces, the PAA adsorption on the colloidal droplets is found to be rapid. Up to 0·1 M NaCl, the range of repulsion and the hydrodynamic radius of the droplet is found to be increasing.