纳米Zr(OH)4及纳米ZrO2对Cu(Ⅱ)的吸附行为

对纳米Zr(OH)4粉体及其在不同温度(350～600℃)下的煅烧产物静态吸附Cu(Ⅱ)的行为进行了研究,并考察了影响静态吸附以及解吸的因素.试验结果表明,煅烧温度越高,样品的吸附效果越差.除了600℃煅烧的样品吸附性能较差外,纳米Zr(OH)4和其它样品在溶液pH》3时对Cu(Ⅱ)有很好的吸附效果,吸附率均大于96%.在实验范围内,吸附量最高可达到26400μg/g.被吸附的Cu(Ⅱ)在低浓度的盐酸(《2.0mol/L)中即可较好的被洗脱,100℃时解吸率可达到96%,同时也有很好的富集效果.     

β-环糊精接枝壳聚糖的合成及其吸附性能

采用乙二醛作为交联物合成了一种β-环糊精接枝壳聚糖,研究了其对水溶液中对硝基苯酚的吸附性能;考察了温度、pH值、吸附时间、酚溶液初始浓度等因素对其吸附性能的影响.结果表明,当吸附时间为20min,pH值为5~6,温度为25℃~35℃,酚溶液初始浓度为80 mg/L时,β-环糊精接枝壳聚糖对对硝基苯酚的吸附性能最佳.     

羟肟酸型吸附树脂对苯酚的吸附性能

通过水杨羟肟酸(SHA)与氯甲基化交联聚苯乙烯微球之间的Friedel-Crafts烷基化反应,实现了SHA在交联聚苯乙烯微球(CPS)上的固载化,制得了SHA功能化微球SHA-CPS。采用红外光谱对其结构进行表征;通过吸附动力学实验和等温吸附实验研究了SHA-CPS微球对苯酚及对硝基苯酚的吸附行为,考察了介质的pH、温度对SHA-CPS微球吸附苯酚的影响,探讨了其吸附热力学与吸附机理。结果表明,SHA-CPS对苯酚及对硝基苯酚具有较强的吸附能力和较快的吸附速率,其吸附能力受温度和pH影响较大。SHA-CPS对苯酚及对硝基苯酚的吸附动力学过程符合准一级方程,其吸附行为符合Freundich吸附模型,属单分子层吸附。SHA-CPS吸附树脂具有良好的重复使用性能。     

镍/碳纳米管复合材料的合成及其吸附性能

本文以二氰二胺和硝酸镍为原料通过煅烧法在900℃合成了镍/碳纳米管(Ni-CNT)的复合材料,采用X射线粉末衍射(XRD),扫描电镜(SEM),透射电镜(TEM),傅里叶变换红外光谱(FTIR)等手段对产物进行了表征,并对其磁性进行了测量。探讨了不同条件下(吸附时间、吸附剂量、pH)产物对刚果红溶液吸附性能的影响。结果表明,当吸附时间达到20 min、吸附剂用量达到1.0 g·L~(-1)且pH值在8时产物对刚果红的吸附率最高,达到97.8%。循环实验表明其五次吸附后依然保持良好的吸附率,且在磁场作用下,吸附剂易与溶液分离。     

催化湿式氧化苯酚的TiO2-CeO2催化剂的制备与表征

 采用共沉淀法制备了催化湿式氧化降解苯酚的TiO2-CeO2催化剂,通过单因素多次实验和正交实验两种不同的实验方式,考察了不同的制备条件如活性组分配比、焙烧温度、焙烧时间和老化过程的pH值等对催化剂活性的影响,证明了老化过程中保持较高pH值对于TiO2-CeO2催化剂的活性具有决定性作用. 当活性组分摩尔配比为1:1, 焙烧温度为450 ℃, 焙烧时间为5.0 h, 老化过程中pH保持为11时得到的催化剂,在反应温度为150 ℃, 氧分压为4.5 MPa的条件下,经90 min的反应,浓度为2.1 g/L的苯酚溶液COD去除率达到了93%. 通过热重差热、N2吸附-脱附、 X射线衍射(XRD)和X射线光电子能谱(XPS)等分析方法揭示了催化剂的微观结构. 结果表明, BET比表面积、表面吸附氧以及表面三价金属元素的相对含量等物理和化学结构特性对催化剂的活性有重要影响.     

改性凹凸棒土对Mo(Ⅵ)的吸附性能研究

研究了改性凹凸棒土吸附Mo(Ⅵ)的性能和机理,探讨了Mo(Ⅵ)溶液的起始浓度、pH值、吸附时间以及温度对此吸附剂吸附Mo(Ⅵ)性能的影响,得出了适宜的吸附条件.用红外对适宜条件下的吸附产物进行了表征.结果表明:改性凹凸棒土吸附Mo(Ⅵ)的适宜条件为:Mo(Ⅵ)溶液初始浓度1.86 mg·L-1,pH值2.20,时间20 min,温度35 ℃.改性凹凸棒土与MoO42-离子间通过静电作用(化学吸附)以及物理吸附相结合.     

弱碱性大孔吸附树脂对腐殖酸的吸附

研究了腐殖酸分子量对弱碱性大孔树脂吸附腐殖酸的影响, 阐明了溶液中小分子芳环化合物(苯酚)及盐含量对树脂吸附腐殖酸的影响机制. 结果表明, 树脂对低分子量腐殖酸的吸附效果要优于高分子量腐殖酸; 低浓度苯酚在溶液中可以促进树脂吸附腐殖酸, 但溶液中苯酚浓度过高会对树脂吸附腐殖酸产生抑制作用; 溶液中的盐对树脂吸附腐殖酸的影响取决于溶液的pH值.     

交联化羟丙基壳聚糖对Cr(Ⅵ)的吸附与结构分析

研究了交联化羟丙基壳聚糖对Cr(Ⅵ)的吸附作用,探讨了溶液的pH值、反应时间、温度、初始浓度等因素对其吸附性能的影响,并且用FTIR、XRD和SEM对吸附前后物质进行了表征与结构分析。实验表明,pH是交联羟丙基壳聚糖吸附Cr(Ⅵ)的主要影响因素。在pH=5时,对Cr(Ⅵ)初始浓度为15mg/L的溶液,可控制温度在20℃左右吸附2h,吸附剂交联羟丙基壳聚糖用量为1g/100mL溶液即能达到满意的吸附效果。吸附后由于交联羟丙基壳聚糖与Cr(Ⅵ)的配位作用使得交联羟丙基壳聚糖的结晶性明显降低;Cr(Ⅵ)的配位使得交联羟丙基壳聚糖的表面形貌发生了改变。     

棕榈纤维制备活性炭纤维及其对水中三氯生的吸附研究

以棕榈纤维为原材料、磷酸为活化剂制备活性炭纤维,通过单因素实验和正交实验深入探讨反应条件对活性炭纤维吸附性能的影响,并确定最佳制备条件。系统研究三氯生在活性炭纤维上的吸附热力学、动力学以及溶液p H值对吸附的影响,并研究比较乙醇洗脱与加热煅烧法对吸附饱和后的活性炭纤维的再生效果。结果表明,磷酸溶液质量分数和碳化温度对活性炭纤维吸附性能影响较大,活化剂浸渍时间对其影响较小,活性炭纤维的最佳制备条件为:磷酸溶液浓度25%,碳化温度400℃,活化时间36h。所制备的活性炭纤维的BET比表面积为1358.478m~2/g、微孔面积为1240.131m~2/g、平均孔径为1.886nm。活性炭纤维对三氯生的吸附等温线符合Langumuir方程,吸附是放热反应。动力学研究表明,吸附反应符合准二级动力学方程,且在5h后基本达到平衡。随着p H值的升高,材料对三氯生的吸附量略有下降。乙醇洗脱和加热煅烧均可有效再生吸附饱和后的活性炭纤维。     

玮晖水务剩余污泥中磷释放的正交试验研究

以开封玮晖水务剩余污泥为对象,研究了不同条件(释放时间、温度、pH、溶剂用量和振荡频率)对污泥磷释放的影响。利用正交试验优化实验条件,得到富磷上清液,并对释磷效率进行了分析。结果表明:在一定条件下,溶剂用量、溶液pH、释放时间以及温度均存在一个最佳值;各因素对污泥磷释放影响的重要性排列顺序是:溶剂用量﹥pH﹥温度﹥释放时间,在溶剂体积50 mL,pH为2,温度为30℃,振荡时间4 h的释放条件下,磷的释放率达到82.12%。污泥在强酸性和强碱性的环境中,污泥释磷效果比较好,溶液初始pH分别是1和13时,污泥磷释放效率分别达到了76.92%和83.75%,大约是中性条件下释磷效率的2倍。     

STUDY ON THE ADSORPTION OF PHENOL BY CHITOSAN FROM AQUEOUS SOLUTION

The effects of pH, initial concentration and temperature on the adsorption of phenol by chitosan were investigated in this paper. The isothermal data was applied to Langmuir linear and the Freundlich linear isotherm equation, and the thermodynamic parameters （AH, AG, AS） were calculated according to the values of binding Langmuir constant, KL. Results indicated that the adsorption between chitosan and phenol was significantly physical in nature, the negative ΔH constant at lower temperature confirmed that more phenol was adsorbed by chitosan at lower temperature. The kinetics of the sorption process of phenol on chitosan was investigated using the pseudo-first order and pseudo-second order kinetics, and results showed that the second order equation model provided the best correlation with the experimental results.     

Photocatalytic degradation of methylene blue and phenol on Fe-doped sulfated titania

Fe-doped sulfated titania (FST) photocatalysts with high photocatalytic activity were prepared from industrial titanyl sulfate solution and characterized using X-ray diffraction (XRD), thermogravimetry analysis?Cdifferential scanning calorimeter (TGA-DSC), Fourier transform infrared spectroscopy (FT-IR), and nitrogen adsorption?Cdesorption techniques. The photocatalytic activity of the FST photocatalyst was evaluated using the photodegradation of methylene blue (MB) and the photooxidation of phenol in aqueous solutions in the presence of UV irradiation, respectively. The effect of various parameters, such as calcining temperature, calcination time, initial concentration of substrate, amount of catalyst and pH value on the photocatalytic activity of FST photocatalyst was investigated. Among the parameters studied, calcining temperature, initial concentration of substrate, and amount of catalyst have a very similar effect on the activity of FST photocatalyst for both the photodegradation of MB and the photooxidation of phenol, while the others have distinct differences. The optimal calcination conditions were 500?°C, 1.5?h and 650?°C, 2.5?h; the optimal catalyst concentration were 1.0 and 1.2?g?L^?1; the optimal pH values were 8 and 4 for the photodegradation of MB and the photooxidation of phenol, respectively. In addition, the mechanism for the high photocatalytic efficiency of FST photocatalyst has also been put forward.     

改性小麦秸杆纤维素球对苯酚吸附性能研究

本文利用制得的改性小麦秸秆纤维素球对苯酚吸附性能进行了研究。实验结果表明:改性小麦秸秆纤维素球对苯酚的吸附30min内基本达到平衡,吸附剂对苯酚吸附量随起始质量浓度的增加而增加,且呈线性关系;在T=298K、pH=5.0时,吸附剂对苯酚的吸附量达到最大。在一定浓度、温度条件下,改性小麦秸秆纤维素球吸附苯酚的过程符合Freundlich吸附模型。吸附再生实验表明,改性小麦秸秆纤维素球对苯酚有较好的吸附再生能力。并对印染废水中的苯酚进行了实际的吸附测定。     

流动注射分析在线研究Cr(Ⅵ)在纳米TiO2表面上的吸附动力学性质

用溶胶-凝聚法在不同的水解和热处理条件下制备了纳米尺寸的TiO₂微粉,所得的TiO₂表面性质迥异,粒径从几个纳米到数百个纳米,晶型也由低温煅烧的锐钛型转成高温处理时的金红石型.利用流动注射微柱富集在线分析方法对Cr(Ⅵ)离子在纳米TiO₂表面上的吸附动力学特性进行了原位表征.     

Optimizing the photocatalytic properties of hydrothermal TiO2 by the control of phase composition and particle morphology. a systematic approach

The possibility of controlling the photocatalytic activity of TiO2 nanoparticles by tailoring their crystalline structure and morphology is a current topic of great interest. In this study, a broad variety of well-faceted particles with different phase compositions, sizes, and shapes have been obtained from concentrated TiOCl2 solutions by systematically changing temperature, pH, and duration of the hydrothermal treatment. The guide to select the suitable experimental conditions was provided by thermodynamic modeling based on available thermochemical data. By combining the results of TEM, HRTEM, XRD, density, and specific surface area measurements, a complete structural and morphological characterization of the particles was performed. Correlation between the photocatalytic activity in the UV photodegradation of phenol solutions and the particle size was established. Prismatic rutile particles with length/width ratio around 5 and breadth of 60-100 nm showed the highest activity. The surface chemistry of the particles was also investigated. Treatments that decrease the surface acidity, such as washing the powders with ammonia solution and/or calcining at 400 degrees C, have detrimental effect on photocatalytic activity. The overall results suggest correlation between particle morphology and photocatalytic activity and indicate that both electron-hole recombination and adsorption at the surface can be rate-controlling processes. The systematic approach presented in this study demonstrates that a substantial improvement of the photocatalytic activity of TiO2 can be achieved by a careful design of the particle morphology and the control of the surface chemistry.     

Study on the fluoride adsorption of various apatite materials in aqueous solution

The aim of this study was to evaluate the defluoridation efficiencies of various sorbents in aqueous solution. These sorbents include synthetic nano-hydroxyapatite (n-HAp), biogenic apatite (bone meal), treated biogenic apatite (bone meal prepared by H₂O₂ oxidation) and geogenic apatite (rock phosphate), which were characterized by XRD, FTIR, TEM and SEM. It has been observed that the defluoridation capacities follow the order: n-HAp > BH₂O₂ > B > rock phosphate. The controlling factors, sorbent dose, initial fluoride concentration, pH, contact time and temperature were investigated. The defluoridation capacities increased with the increase in the initial fluoride concentration and contact time, decreased with the increase in the sorbent dose. The optimum pH range for removal of fluoride on various apatite sorbents was considered to be 5.0-6.0. The fluoride adsorption can be explained by Langmuir, Freundlich isotherms, and the adsorption kinetic data follow the pseudo-second-order model. Thermodynamic parameters such as ΔH⁰, ΔS⁰ and ΔG⁰ indicated that the adsorption on various apatite sorbents was spontaneous and endothermic. These results showed that bone meal is a promising material for fluoride adsorption.     

Adsorption of phenol from water by N-butylimidazolium functionalized strongly basic anion exchange resin

N-butylimidazolium functionalized strongly basic anion exchange resin with Cl(-) anion (MCl) was prepared by anchoring N-butylimidazole onto chloromethylated macroporous styrene-divinylbenzene (St-DVB) copolymer. The adsorption performances of phenol on MCl were studied using the batch technique at acidic and alkaline pH. The studies showed that phenol can be effectively removed at both acidic and alkaline pH. The maximum adsorption was achieved at about pH 11. The maximum adsorption capacities of phenol on MCl at pH 6.6 and 11.2 were 80.2 and 92.9 mg/g, respectively. The adsorption mechanism was mainly molecular adsorption at acidic pH and anion exchange at alkaline pH. The adsorption of phenol was hindered by the presence of Cl(-) and SO(4)(2-) at alkaline pH due to the competitive anion exchange reaction. The adsorption of molecular phenol species on MCl at acidic pH was exothermic, and the anion exchange of phenolate species by MCl at alkaline pH was endothermic. Desorption of phenol from loaded adsorbent was achieved by using 0.5 mol/L NaOH and 0.5 mol/L NaCl mixed solution. MCl can simultaneously remove phenol and Cr(VI) from their mixtures, which would be of practical value in actual industrial wastewater treatment.     

Adsorption characteristics of poly(styrene-co-divinylbenzene) resin functionalized with methoxy and phenoxy groups for phenol

Two macroporous crosslinked poly(styrene-co-divinylbenzene) resins functionalized with methoxy and phenoxy groups, PVBME and PVBPE were prepared and their adsorption characteristics for phenol were studied in hexane as well as in aqueous solution. It was shown that the equilibrium adsorption capacity of phenol onto PVBPE was a little larger than that onto PVBME at the same temperature and equilibrium concentration. The adsorption onto PVBME in hexane can be correlated to Langmuir isotherm model, whereas the semi-empirical Freundlich isotherm model characterized the adsorption onto PVBPE better. The adsorption thermodynamic parameters were calculated and it was found that the adsorption enthalpy, adsorption free energy, and adsorption entropy were all negative, and the adsorption thermodynamic parameters onto PVBPE were more negative than the corresponding ones onto PVBME. The relationship of the adsorption capacity with the equilibrium concentration was linear in aqueous solution. The adsorption was hypersensitive to the solution pH in aqueous solution, and the optimum pH was determined to be 6.0. The adsorption dynamics of phenol onto PVBPE in aqueous solution was investigated and it was seen that the adsorption can be well fitted by the pseudo-first-order rate equation.     

ADSORPTION OF METHYLENE BLUE FROM AQUEOUS SOLUTION ON ATTAPULGITE

Batch adsorption experiments were carried out for the removal of methylene blue （MB） from aqueous solution using attapulgite as adsorbent. The effects of various parameters such as temperature, contact time, the pH value, and attapulgite dosage on the adsorption performance were investigated. The standard curve and regression equation were established by spectrophotometry. The adsorption experimental results showed that the adsorption equilibrium data were well in accord with Langmuir adsorptive model. The optimal result was acquired under the experimental condition of attapulgite dosage 0.18g, MB concentration 50.0mg/L, pH 10, and adsorption time 20min at room temperature.