羧甲基壳聚糖微球对曙红Y的吸附研究

以壳聚糖粉末为原料,戊二醛进行交联、羧甲基化,制得羧甲基壳聚糖微球。采用SEM对壳聚糖微球的形貌、大小进行了表征,研究羧甲基壳聚糖微球对曙红Y的吸附性能。探讨吸附剂用量、吸附时间、曙红Y的初始浓度、pH、温度对脱色率的影响,研究吸附等温曲线和动力学方程。实验结果表明,曙红Y初始浓度增加时,吸附量也增加,直到吸附饱和,羧甲基壳聚糖的饱和吸附量为75 mg/g;相同条件下,吸附剂用量增加时,平衡吸附量减小,去除率增加。298 K,吸附剂投加量为1 g,pH=7.0,吸附时间为40 min时,初始浓度为560 mg/L的曙红Y染料的去除率可以达到90%以上。符合Langmuir等温方程和二级吸附动力学方程。     

羟基磷灰石微球的制备及废水除氟性能评价

以壳聚糖为模板,通过反向乳液聚合制备得到羟基磷灰石微球（CTS-HAP）,在利用X射线衍射（XRD）、扫描电镜（SEM）、能谱（EDS）、红外光谱（FT-IR）对改性和吸附前后微球进行微观分析基础上,测定其在氟化钠溶液中的平衡吸附量为17.8 mg/g（吸附pH=4）,微球对氟离子吸附符合多层分子吸附模型——Freundlich模型。针对氟离子质量浓度为2 789.2 mg/L、pH为1.7的酸性高含氟废水,设计二阶段除氟。初步除氟阶段氢氧化钙用量为10 864 mg/L,剩余氟离子质量浓度为200.6 mg/L,去除率为92.81%;深度除氟采用CTS-HAP微球吸附法,CTS-HAP微球用量为24 g/L,去除率为95.2%,满足处理后废水氟离子浓度要求。     

壳聚糖交联微球对水中镍离子的吸附性能

以戊二醛为交联剂,采用反相悬浮法合成了壳聚糖交联微球,研究了该微球对Ni2+的吸附性能及其重复使用性。结果表明,壳聚糖交联微球对Ni2+的吸附条件是25℃时,p H 7.0,在50 m L质量浓度为300 mg/L Ni2+溶液中,投加0.05 g吸附剂,吸附2 h,吸附量为45.65 mg/g。该微球经0.1 mol/L盐酸解吸后可再生,重复使用7次,吸附量仍可达原来的81.9%。微球良好的再生性显著降低了处理成本,提高了处理效果,减少了二次污染。     

磁性复合微球对铬离子的吸附条件研究

以磁性纳米壳聚糖微球为载体,戊二醛为交联剂,采用共价交联法,负载鞘细菌S9构建磁性鞘细菌微球。通过单因素和正交设计实验,对该复合生物微球吸附铬离子的条件进行研究,结果发现磁性复合微球对铬离子的吸附性能明显高于磁性纳米壳聚糖和游离鞘细菌,同时得到最适吸附组合为A1B1C1,即当铬离子初始浓度为40mg/m L,吸附温度30℃,吸附时间30min,磁性复合微球对铬离子的吸附作用最佳,吸附量和吸附率分别为58.16mg/g和44.52%。     

微波活化赤泥对分散艳蓝E-4R的吸附去除研究

研究了赤泥对染料废水中分散艳蓝E-4R的吸附作用,结果表明,微波活化后赤泥具有良好的吸附效果,对分散艳蓝E-4R的吸附行为符合Langmuir等温方程。活化后赤泥对分散艳蓝E-4R的饱和吸附量为42.19mg/g,其中影响吸附效果的因素有赤泥投加量、温度和pH值。经过优化得到最佳条件:温度为40℃,pH值为3.0,赤泥投加量为15g/L。在最佳条件下,吸附时间为30min,活化赤泥第一次使用时对质量浓度为300g/L的分散艳蓝E-4R的脱色率、COD及TOC去除率分别达到99.07%、、64.08%和50%。经过3次使用后,赤泥对染料的吸附能力下降,经微波再生后吸附性能得到恢复。     

磁性竹炭-壳聚糖复合材料吸附去除水体中日落黄染料研究

通过微乳化法制备了磁性竹炭-壳聚糖复合吸附剂,考察了吸附剂配比、吸附剂投加量、染料初始浓度、溶液p H值、温度及动力学和热力学等因素对食品染料日落黄的吸附影响。试验结果表明,采用壳聚糖、竹炭、Fe3O4配比为10∶5∶6的吸附剂,在其投加量为1 g/L的条件下,对50 m L初始质量浓度为20 mg/L、初始p H值为5.5的日落黄溶液进行吸附,脱色率可达93.41%。吸附剂对日落黄的吸附等温线符合Freundlich模型,吸附过程符合拟二级动力学方程。鉴于此磁性竹炭-壳聚糖复合吸附剂良好的吸附性能及简便的制备方法,可应用于工业印染废水的脱色处理中,具有很大的潜力。     

粉煤灰基地质聚合物微球吸附水中铜（Ⅱ）的研究

以粉煤灰为原料,以氢氧化钾溶液为碱激发剂,将二者按照优化配比（氧化钾与氧化铝物质的量比为1.5、水与氧化钠物质的量比为18）混合均匀后,采用悬浮固化法制备粉煤灰基地质聚合物微球,将微球用于吸附含铜废水中的铜（Ⅱ）。通过X射线衍射（XRD）仪、比表面积与孔径分析仪、BT-99型水质分析仪对微球进行了表征,探究了吸附时间、微球用量、吸附温度、铜（Ⅱ）溶液pH、铜（Ⅱ）溶液质量浓度等因素对微球吸附铜（Ⅱ）的影响。结果表明,粉煤灰基地质聚合物微球较粉煤灰原料具有更大的孔径和比表面积,具有更好的对铜（Ⅱ）的吸附效果,在最优条件下[微球用量为0.20 g、溶液pH为5、铜（Ⅱ）初始质量浓度为100 mg/L、溶液体积为100 mL、吸附温度为40 ℃、吸附时间为24 h]微球对铜（Ⅱ）的吸附量为45.62 mg/g、去除率达到91.46%,吸附过程遵循准二级动力学方程。     

磁性壳聚糖微球对酸性嫩黄G吸附行为的研究

随着我国工业化进程的快速推进，大量印染废水随之产生。印染废水具有色度高、有机物含量高、难降解等特点，且存在致畸、致癌等健康风险，对环境和人类健康造成极大危害。本研究采用反相乳液法制备了磁性壳聚糖微球（MCPs），并系统研究了其对酸性嫩黄G染料的吸附行为。结果表明，MCPs对酸性嫩黄G的平衡吸附量（qe）随染料初始浓度的增大而增大，随pH的减小而增大。在MCPs添加量为0.05 g、染料初始质量浓度为1 000 mg/L、溶液体积为50 mL、pH为3.5、吸附时间为24 h的条件下，MCPs对酸性嫩黄G的吸附量达到272.86 mg/g。在时间尺度上，前200 min内MCPs对酸性嫩黄G的吸附量随时间延长迅速增加，200～480 min时吸附速率逐渐降低，480 min后吸附基本达到平衡。吸附动力学表明，MCPs对酸性嫩黄G的吸附过程符合准二级动力学模型，属于化学吸附。Langmuir模型相关系数高达0.924 9，表明MCPs吸附酸性嫩黄G的过程为单分子层吸附。本研究可为MCPs在印染废水处置领域的基础及应用研究提供一定思路。     

壳聚糖对活性翠蓝模拟印染废水的吸附性能研究

以壳聚糖为吸附剂,研究了其对活性翠蓝模拟印染废水的吸附性能。探讨了壳聚糖用量、介质的pH值、温度、时间、染料浓度对吸附性能的影响。结果表明:壳聚糖用量增加,脱色率和吸附量逐渐减小;介质的pH在3～7范围内,吸附性能较好;温度对吸附性能影响不大;一定范围内,脱色率和吸附量随活性翠蓝浓度的增大逐渐增大。经单因素试验得出了最优工艺条件为:壳聚糖加入量为0.05g、温度为45℃、反应时间为120min、活性翠蓝溶液浓度为60mg/L、体积为50mL、介质的pH为6.9的条件下,脱色率可达到93.43%,吸附量可达到58.56mg/g。且其吸附行为符合Langmuir吸附模型。IR和SEM检测证实了壳聚糖与活性翠蓝之间的交互作用。     

滑石粉处理阳离子染料废水的试验研究

研究滑石粉吸附去除水中阳离子染料的可行性.选取亚甲基蓝、结晶紫、中性红3种阳离子染料,考察染料废水浓度、滑石粉投加量、反应温度、搅拌时间等因素对滑石粉净化染料废水的影响,确定最佳吸附条件.结果表明,当染料质量浓度为0.015 g/L、滑石粉投加量为10g/L、温度为20℃、慢速搅拌时间为10 min时,3种染料废水的脱...     

Removal of methylene blue dye from aqueous solutions by a new chitosan/zeolite composite from shrimp waste: Kinetic and equilibrium study

The adsorption of methylene blue dye (MBD) from aqueous solutions was investigated using a new composite made up of shrimp waste chitosan and zeolite as adsorbent. Response surface methodology (RSM) was used to optimize the effects of process variables, such as contact time, pH, adsorbent dose and initial MBD concentration on dye removal. The results showed that optimum conditions for removal of MBD were adsorbent dose of 2.5 g/L and pH of 9.0, and initial MBD concentration of 43.75 mg/L and contact time of 138.65 min. The initial concentration of dye had the greatest influence on MBD adsorption among other variables. The experimental data were well fitted by the pseudo-second order kinetic model, while the Freundlich isotherm model indicated a good ability for describing equilibrium data. According to this isotherm model, maximum adsorption capacity of the composite was 24.5 mg/g. Desorption studies showed that the desorption process is favored at low pH under acidic conditions.     

The application of a natural chitosan/bone char composite in adsorbing textile dyes from water

Colored wastewaters are one of the common waste contaminants which are derived from various industries, threatening aquatic environments. Thus, it is necessary to treat them before discharge. Among various remediation technologies, adsorption is one of the popular treatment methods because of its simplicity and cost-efficiency. So, in the present study, the adsorption potential of a natural chitosan/bone char composite was investigated in adsorbing the Direct Brown 166 dye (DB-166) from aqueous solution. To investigate the adsorption potential of the chitosan/bone char composite, the effects of influencing parameters were studied. Accordingly, the optimum removal efficiency was determined at an initial pH of 3, a contact time of 60?min, an initial dye concentration of 20?mg/L, an adsorbent dosage of threatening 4?g, a mixing speed of 150?rpm, and a temperature of 55°C. Also, the maximum adsorption efficiency and capacity were obtained to be 99.8% and 21.18?mg/g, respectively. To evaluate the equilibrium and dynamics, isotherm and kinetic models were investigated. As a result, the Langmuir isotherm (R²?=?0.996) and pseudo-second-order kinetic model (R²?=?0.999) fitted the experimental data well. These results revealed that the chitosan/bone char composite can be used as an efficient adsorbent for the decolorization of aquatic solutions.     

Dispersion of FeOOH on Chitosan Matrix for Simultaneous Removal of As(III) and As(V) from Drinking Water

Bio-inorganic chitosan based spherical shaped beads were prepared by dispersing rod-shaped FeOOH nanoparticles into a chitosan matrix for the removal of pure As(III) and As(V) from aqueous media, such as drinking water. A homogeneous mixture of chitosan and ferric nitrate, ferric chloride was prepared respectively with or without oxalic acid. The mixture was added dropwise in to a NaOH bath, where iron salts reacted with NaOH to form FeOOH particles. The scanning electron microscopy (SEM) showed that rod shaped FeOOH particles were distributed homogenously in the chitosan matrix. Diffuse reflective UV-vis (DRUV) spectra revealed that hydrated iron oxide formed a complex with functional groups in chitosan. Adsorption of As(III) and As(V) on different iron salt based bead was found to be pH dependent. The bead prepared from iron nitrate showed better performance for arsenic removal from aqueous solution over the bead that was prepared using iron chloride salt. The bead prepared using chitosan and iron-FeOOH is known as a chitosan-iron oxyhydroxide (CFOH) bead. The CFOH beads were found to be more efficient in removing As(III) from the solution compared to As(V). The adsorption of As(III) and As(V) from aqueous solution on CFOH beads was studied under equilibrium conditions in the concentration range of 1 mg/L to 50 mg/L in the presence of 0.05 M NaNO₃ at pH 6.5 and 298 K temperature. The maximum adsorption capacity of the CFOH bead was found to be 5.4 mg/g for As(V) and 7.2 mg/g for As(III) using the Langmuir equation. The presence of sulphate, phosphate, and silicate in aqueous solution had no effects on adsorption of either As(III) or As(V) on CFOH beads but decreased significantly at pH> 8.     

Adsorption of Pb(II) Ions Using Humic Acid Coated Chitosan-Tripolyphosphate (HA-CTPP) Beads

A new humic acid (HA) based adsorbent was prepared by coating humic acid on chitosan tripolyphosphate (CTPP) beads. Humic acid-chitosan tripolyphosphate (HA-CTPP) beads thus obtained were characterized using Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy. Swelling capacity studies of CTPP and HA-CTPP beads conducted in the pH range, pH = 1–10 showed that HA-CTPP beads are more stable against swelling than CTPP beads. Equilibration of HA-CTPP beads in water for different pH showed that leaching of HA from the beads is negligible and the beads are stable for adsorption applications. Adsorption of Pb(II) ions onto HA-CTPP beads were studied as a function of various operational parameters such as initial pH, metal ion concentration, and contact time. The results showed that HA-CTPP beads are suitable for Pb(II) ions adsorption and the kinetics of sorption very well fit into pseudo-second order model. The Langmuir model was found to be more suitable for explaining the observed adsorption data, giving a theoretical maximum adsorption capacity of 223.7 mg/g. HA-CTPP beads could possibly find application in the treatment of waste water contaminated with other toxic and/or heavy metals.     

改性硅藻土处理乙烯碱性废液的研究

本研究采用改性硅藻土处理乙烯废碱液,通过单因素实验,考察了改性硅藻土处理乙烯废碱液的吸附温度、吸附时间、改性硅藻土加入量和乙烯废碱液的pH对乙烯废碱液中硫去除率的影响,确定了改性硅藻土处理乙烯废碱液的最佳工艺条件。实验结果表明,其最佳工艺条件:吸附时间为40 min、吸附温度为20℃、改性硅藻土加入量为1.5 g、乙烯废碱液的pH为3。在此条件下,乙烯废碱液中硫浓度由560.4 mg/L降到29.4 mg/L,硫去除率达94.75%;乙烯废碱液的COD由148000 mg/L降到12000 mg/L,COD去除率达91.89%,改性硅藻土在乙烯废碱液处理方面具有很好的应用前景。     

负载壳聚糖的凹凸棒土对Ni~(2+)离子吸附性能的研究

天然凹凸棒土(AT)经盐酸和热处理制得活化凹凸棒土(MAT).以壳聚糖(CTS)改性MAT制得负载壳聚糖的凹凸棒土(CMAT)。用扫描电镜(SEM)和红外光谱(IR)对AT、MAT和CMAT的结构进行了表征。考察了Ni2+离子溶液的初始浓度、pH、吸附时间以及吸附温度对CMAT和CTS两种吸附剂吸附Ni2+离子性能的影响,得出了适宜的吸附条件。用IR对这两种吸附剂及其适宜条件下得到的吸附产物的结构进行了表征,并作了比较。结果表明,CMAT吸附Ni2+离子的适宜条件为:Ni2+离子溶液初始浓度40.0 mg/L,pH 4.03~6.04,吸附时间1.5 h,吸附温度25℃其最大吸附容量为15.2 mg/L;CTS吸附Ni2+离子的适宜条件为:Ni2+离子溶液初始浓度40.0 mg/L,pH3.00~4.12,吸附时间1.5 h,吸附温度35℃,其最大吸附容量为12.3 mg/L。在相同实验条件下,CMAT对Ni2+离子的吸附性能高于CTS,且二者的吸附行为均符合Langmuir吸附等温式。IR分析表明,CMAT对Ni2+离于的吸附包含化学吸附和物理吸附两个过程。而CTS主要是化学吸附。     

二氧化硫脲改性壳聚糖及其处理对焦磷酸铜废水

通过曼尼希反应一步法合成了二氧化硫脲(TDO)改性壳聚糖(CS)吸附剂(CS-TDO),对其进行了表征。以CS-TDO对Cu(Ⅱ)吸附性能为指标,探讨了合成优化条件。对比研究了CS和CS-TDO对焦磷酸铜电镀废水的处理效果。结果表明,CS-TDO已成功制备。合成CS-TDO的优化工艺为壳聚糖1.5 g,温度40℃,pH为5,转速1 000 r/min,m(CS):m(甲醛):m(TDO)=2.2:5:1。在此条件下,合成的CS-TDO对Cu(Ⅱ)(质量浓度100 mg/L)的去除率达到88.46%,吸附量为80.42 mg/g。当投加量为2.0 g/L时,CS-TDO对焦磷酸铜废水的去除率为98.23%,相比CS提高12.56百分点。研究结果可为壳聚糖衍生物的开发及其工业化应用提供参考。     

Removal of copper(II) ions from aqueous solution onto chitosan and cross-linked chitosan beads

The adsorption of Cu(II) ions onto chitosan and cross-linked chitosan beads has been investigated. Chitosan beads were cross-linked with glutaraldehyde (GLA), epichlorohydrin (ECH) and ethylene glycol diglycidyl ether (EGDE) in order to obtain sorbents that are insoluble in aqueous acidic and basic solution. Batch adsorption experiments were carried out as a function of pH, agitation period, agitation rate and concentration of Cu(II) ions. A pH of 6.0 was found to be a optimum for Cu(II) adsorption on chitosan and cross-linked chitosan beads. Isotherm studies indicate Cu(II) can be effectively removed by chitosan and cross-linked chitosan beads. Adsorption isothermal data could be well interpreted by the Langmuir equation. Langmuir constants have been determined for chitosan and cross-linked chitosan beads. The experimental data of the adsorption equilibrium from Cu(II) solution correlated well with the Langmuir isotherm equation. The uptakes of Cu(II) ions on chitosan beads were 80.71 mg Cu(II)/g chitosan, on chitosan-GLA beads were 59.67 mg Cu(II)/g chitosan-GLA, on chitosan-ECH beads were 62.47 mg Cu(II)/g chitosan-ECH and on chitosan-EGDE beads were 45.94 mg Cu(II)/g chitosan-EGDE. The Cu(II) ions can be removed from the chitosan and cross-linked chitosan beads rapidly by treatment with an aqueous EDTA solution and at the same time the chitosan and cross-linked chitosan beads can be regenerated and also can be used again to adsorb heavy metal ions.     

Preparation and characterization of porous chitosan–tripolyphosphate beads for copper(II) ion adsorption

Porous chitosan–tripolyphosphate beads, prepared by the ionotropic crosslinking and freeze‐drying, were used for the adsorption of Cu(II) ion from aqueous solution. Batch studies, investigating bead adsorption capacity and adsorption isotherm for the Cu(II) ion, indicated that the Cu(II) ion adsorption equilibrium correlated well with Langmuir isotherm model. The maximum capacity for the adsorption of Cu(II) ion onto porous chitosan–tripolyphosphate beads, deduced from the use of the Langmuir isotherm equation, was 208.3 mg/g. The kinetics data were analyzed by pseudo‐first, pseudo‐second order kinetic, and intraparticle diffusion models. The experimental data fitted the pseudo‐second order kinetic model well, indicating that chemical sorption is the rate‐limiting step. The negative Gibbs free energy of adsorption indicated a spontaneous adsorption, while the positive enthalpy change indicated an endothermic adsorption process. This study explored the adsorption of Cu(II) ion onto porous chitosan–tripolyphosphate beads, and used SEM/EDS, TGA, and XRD to examine the properties of adsorbent. The use of porous chitosan–tripolyphosphate beads to adsorb Cu(II) ion produced better and faster results than were obtained for nonporous chitosan–tripolyphosphate beads. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013