黄原酸化交联壳聚糖的制备及表征

微波辐射下,以壳聚糖为原料,环氧氯丙烷为交联剂,二硫化碳为改性剂,制得了黄原酸化交联壳聚糖(XCCTS)吸附剂。采用扫描电镜、红外光谱和X射线衍射光谱对XCCTS吸附Cu2+前后的形貌和结构进行了表征,并研究了黄原酸化条件对Cu2+在树脂上的吸附量的影响。结果表明,XCCTS表面粗糙,具有结晶性,分子中具有能够吸附Cu2+的巯基和羟基。随着CS2用量的增大,吸附时间的延长,XCCTS对Cu2+吸附量均是先增大后减小,二硫化碳用量为2 mL,微波黄原酸化时间为3min时,XCCTS对Cu2+的吸附量可达到44.32 mg/g。     

黄原酸化膨润土对甲基橙的吸附性能研究

研究了黄原酸化膨润土(XB)对甲基橙的吸附性能,考察了甲基橙初始浓度、吸附时间、温度、pH值、吸附剂用量对其吸附性能的影响。结果表明:在15～25℃,[甲基橙]起始=300mg/L,pH=5～6,XB用量0.5g,吸附时间80min时,XB对甲基橙的去除率最高达98.5%,处理后染料废水可达标排放。吸附动力学研究表明,吸附过程符合准二级动力学吸附模型,以化学吸附为主。     

多孔壳聚糖交联树脂的制备及对磷酸盐中磷的吸附

以壳聚糖为原料,二甲苯为分散剂、乙酸乙酯为致孔剂、环氧氯丙烷为交联剂,利用反相悬浮交联法制备了多孔壳聚糖交联树脂;通过红外光谱对树脂结构进行表征并对其性能参数进行了测定;系统考察了该多孔树脂对磷酸盐中磷的吸附特性,结果表明,溶液pH和温度对吸附率的影响较大,在磷酸根浓度为2 mg/L,pH=3,溶液温度为60℃时吸附率达到85.8%;吸附过程符合二级动力学吸附,符合Langmuir吸附模型,吸附为吸热、熵增、自发的过程。在7次吸附解吸循环试验中,相邻2次的吸附量变化不超过0.03 mg/g,说明多孔树脂具有良好的循环吸附稳定性。     

交联球形壳聚糖树脂制备与吸附性能研究

介绍了壳聚糖—乙酸溶液制备球交联形壳聚糖树脂的方法 ,考察了各种制备因素对产品性能的影响 ,得到了较为合适的反应条件。产品溶酸性能、吸附性能有较大提高 ,并且容易再生。     

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。     

乙二醛交联壳聚糖树脂对Cu(Ⅱ)吸附研究

以乙二醛为交联剂,由壳聚糖合成了一种交联壳聚糖树脂.研究了不同温度下其对Cu(Ⅱ)的静态吸附性能,测定了不同温度下的吸附曲线,并通过FTIR及XRD对交联壳聚糖树脂产物和吸附Cu(Ⅱ)后的材料结构进行了表征.结果表明,乙二醛交联壳聚糖树脂在40℃时对铜离子的平衡吸附量为78mg/g,不同温度下的吸附过程符合一级动力学模...     

改性壳聚糖对电镀废水中重金属离子的吸附

利用壳聚糖与香草醛反应制备出更为高效的天然高分子吸附剂－－改性壳聚糖（VCG）。在静态条件下，研究了改性壳聚糖（VCG）对重金属离子Pb^2 ,Cu^2 ,Cd^2 ,Zn^2 ,Ni^2 的吸附，结果表明，VCG对重金属离子具有较好的吸附性能，PH值是影响吸附的主要因素，络合反应是主要的吸附形式，在25℃、PH＝4时,深度分别为30mg/L的Pb^2 ,Cu^2 ,Cd^2 ,Zn^2 ,Ni^2 溶液被VCG吸附2h后，重金属离子的除去率达97％以上，含镍（Ⅱ）电镀废水经VCG吸附后，达到国家排放标准。     

黄原酸化膨润土的制备及脱除亚甲基蓝的性能研究

对膨润土进行改性制得黄原酸化膨润土(XB),通过FT-IR、TG、SEM、粒度分析对XB进行了表征,结果表明,碳硫键接到了膨润土表面,使其亲水性降低,表面积增大。通过XB对亚甲基蓝的吸附试验,表明XB是一种环境友好型吸附剂。考察了亚甲基蓝初始浓度、吸附时间、温度、pH值、吸附剂用量对其吸附性能的影响。结果表明:在25℃,pH=7～8,亚甲基蓝初始浓度100mg/L,XB用量为2g/L,吸附30min时,XB对亚甲基蓝的脱色率达到99.93%,处理后废水可达标排放。     

微波辐射下交联壳聚糖树脂的制备及吸附性能

以壳聚糖为原料,微波辐射加热条件下,利用反相悬浮法制备甲醛-戊二醛交联壳聚糖树脂,用于吸附废水中硫酸根离子。运用红外光谱、扫描电镜以及X射线能谱元素分析对吸附剂结构进行表征,采用静态吸附法考察制备条件对其吸附量的影响。结果表明:交联反应主要发生在壳聚糖的氨基(-NH2)和一级羟基(C6-OH)上;当微波辐射甲醛反应时间为15min,微波辐射戊二醛反应时间为30min,甲醛用量6mL以及戊二醛用量4mL,所得的交联壳聚糖树脂对硫酸根离子的吸附量达到最大。     

印迹改性磁性交联壳聚糖的表征及吸附性能

为了提高壳聚糖（CS）对Pb²⁺的去除能力,制备了印迹改性磁性交联壳聚糖（Pb-TMCS）,采用FTIR、SEM和XRD对其结构和形态进行了表征,研究了Pb-TMCS对Pb²⁺的吸附、脱附性能及选择性。结果表明：与CS相比,Pb-TMCS的表面孔隙和褶皱增多;Pb-TMCS引入了更多的-OH和-NH₂;Pb-TMCS内部包覆磁性物质Fe₃O₄,Pb-TMCS对 CS的相对选择性系数大于2;Pb-TMCS对Pb²⁺的吸附量从CS的25.57 mg/g提高到45.26 mg/g,脱附3次后仍可重复使用。Pb-TMCS回收方便,对Pb²⁺选择吸附性能好,无污染,在重金属废水处理中具有广阔的应用前景。     

质子化交联壳聚糖对甲基橙的吸附研究

研究了吸附剂投加量、甲基橙初始浓度、pH值、吸附时间等条件对甲基橙脱色效果的影响。结果表明,在质子化壳聚糖用量为3.6g/L条件下,对质量浓度低于200mg/L甲基橙溶液的吸附率不低于90%。拟二级动力学模型能很好地描述其吸附过程;吸附等温线符合Langmuir模型。质子化壳聚糖在较宽的pH值范围内对甲基橙具有较好的脱色效果,可提高壳聚糖的利用价值。     

复配壳聚糖树脂对Cu2+的等温吸附及吸附动力学研究

以活性炭和壳聚糖为复配原料合成复配壳聚糖树脂,对树脂的结构进行扫描电镜和红外表征,并研究了复配壳聚糖树脂对Cu2+的等温吸附动力学特性。结果表明复配改性后的壳聚糖具有多孔结构,比表面积增大;交联反应发生在壳聚糖分子中的氨基和羟基上;复配壳聚糖树脂对Cu2+的吸附符合Langmuir和Freundlich等温吸附模型;其吸附动力学过程符合Lagergren二级动力学方程,吸附过程容易进行。     

一种新型两亲性超高交联树脂对p-硝基苯酚的吸附行为研究

选用N-乙烯基吡咯烷酮和间苯型不饱和聚酯为单体,合成了新型两亲性的超高交联吸附树脂(NU).通过静态吸附实验,研究了NU树脂在不同温度下吸附水溶液中p-硝基苯酚的热力学和动力学特性,结果表明,吸附符合一级动力学方程,NU树脂吸附p-硝基苯酚符合Freundlich模型,通过计算△H＜0,为放热反应.     

氨基酸修饰的吸附树脂对间苯三酚的吸附效果

采用脯氨酸、甘氨酸或L-谷氨酸三种氨基酸分别在NDA150上进行化学修饰(分别代号为ZHP02、ZHG02、ZHL02),并以NDA150为参照,用红外、比表面积孔径测定仪和元素分析仪进行了表征。在不同温度下将修饰的树脂用于对水中间苯三酚进行静态吸附实验,考察其吸附容量,并以实际废水进行了动态吸附和脱附验证,结果表明,羧酸基对吸附间苯三酚具有较好的吸附选择性,静态吸附和脱附条件的比较结果也证实了吸附过程中存在不可逆化学吸附。     

化学修饰制备氢键型吸附树脂

综述了酚羟基、胺基、羰基、羧基和酯基等多种化学修饰的氢键型吸附树脂的国内外研究,总结了氢键型吸附树脂中氢键吸附的主要影响因素,为合成新型氢键高分子吸附剂提供了研究思路。指出了氢键型吸附树脂目前研究中存在的问题,并提出进一步的研究方向。     

Nitrate removal from aqueous solutions by cross-linked chitosan beads conditioned with sodium bisulfate

The investigation of adsorption of nitrate onto chitosan beads modified by cross-linking with epichlorohydrin (ECH) and surface conditioning with sodium bisulfate was performed. The results indicated that both cross-linking and conditioning increased adsorption capacity compared to normal chitosan beads. The maximum adsorption capacity was found at a cross-linking ratio of 0.4 and conditioning concentration of 0.1 mM NaHSO₄. The maximum adsorption capacity was 104.0 mg g⁻¹ for the conditioned cross-linked chitosan beads at pH 5, while it was 90.7 mg g⁻¹ for normal chitosan beads. The Langmuir isotherm model fit the equilibrium data better than the Freundlich model. The mean adsorption energies obtained from the Dubinin-Radushkevich isotherm model for all adsorption systems were in the range of 9.55–9.71 kJ mol⁻¹, indicating that physical electrostatic force was potentially involved in the adsorption process.     

Adsorption of dyes from aqueous solutions on activated charcoal

Adsorption of industrially important dyes namely bromophenol blue, alizarine red-S, methyl blue, methylene blue, eriochrome black-T, malachite green, phenol red and methyl violet from aqueous media on activated charcoal has been investigated. The effect of shaking time, pH and temperature on the adsorption behaviour of these dyes has been studied. It was noted that adsorption of all the dyes on activated charcoal decreases with an increase in the pH and the temperature. The adsorption isotherms at different temperatures were found to be of L-type. Adsorption data was fitted to Freundlich, BET and Langmuir isotherms and various adsorption parameters have been calculated. The thermodynamic parameters such as DeltaG, DeltaH and DeltaS were calculated from the slopes and intercepts of the linear variation of lnK against 1/T, where K is the adsorption coefficient obtained from Langmuir equation, was used. The calculated values for the heat of adsorption and the free energy indicate that adsorption of dyes is favored at low temperatures and the dyes are chemisorbed on activated charcoal.     

Removal of fluoride from aqueous solution using protonated chitosan beads

In the present study, chitosan in its more usable bead form has been chemically modified by simple protonation and employed as a most promising defluoridating medium. Protonated chitosan beads (PCB) showed a maximum defluoridation capacity (DC) of 1664mgF-/kg whereas raw chitosan beads (CB) possess only 52mgF-/kg. Sorption process was found to be independent of pH and altered in the presence of other co-existing anions. The sorbents were characterized using FTIR and SEM with EDAX analysis. The fluoride sorption on PCB follows both Freundlich and Langmuir isotherms. Thermodynamic parameters, viz., DeltaG degrees , DeltaH degrees DeltaS degrees and Ea indicate that the nature of fluoride sorption is spontaneous and endothermic. The sorption process follows pseudo-second-order and intraparticle diffusion kinetic models. 0.1M HCl was identified as the best eluent. The suitability of PCB has been tested with field samples collected from a nearby fluoride-endemic area.