复合改性5A分子筛对水中Cr~(3+)的吸附研究

对复合改性5A分子筛去除水中Cr⁽³⁺⁾的效果进行了研究。采用氢氧化钠和硝酸铁为改性试剂对5A分子筛进行复合改性,考察分子筛用量、溶液pH值、Cr(3+)的效果进行了研究。采用氢氧化钠和硝酸铁为改性试剂对5A分子筛进行复合改性,考察分子筛用量、溶液pH值、Cr⁽³⁺⁾溶液初始浓度、吸附时间对Cr(3+)溶液初始浓度、吸附时间对Cr⁽³⁺⁾去除率的影响。用Langmuir和Freundlich等温吸附模型对分子筛吸附Cr(3+)去除率的影响。用Langmuir和Freundlich等温吸附模型对分子筛吸附Cr⁽³⁺⁾的吸附过程进行拟合,并探讨分子筛吸附Cr(3+)的吸附过程进行拟合,并探讨分子筛吸附Cr⁽³⁺⁾过程的吸附动力学模型。结果表明,经0.4 mol/L氢氧化钠,6 mmol/L硝酸铁复合改性后效果最好,较未改性的5A分子筛的吸附容量提升了176%,改性前后分子筛的吸附均符合Langmuir吸附等温模型,吸附速率符合Lagergren准二级速率方程。     

电解法原位合成锰氧化物处理模拟含锶放射性废水

以88Sr作为模拟非放射性同位素,对电解法原位合成锰氧化物处理模拟核电厂放射性废水中Sr~(2+)的工艺条件进行了研究。考察了电解电压、反应时间、反应结束后搅拌时间、温度以及pH对出水Sr~(2+)质量浓度的影响,并通过正交试验得出最佳反应条件。结果表明,在模拟废水Sr~(2+)初始质量浓度为5 mg/L条件下,最佳工艺条件:电解电压为7 V,反应温度为50℃,pH为10,电解时间为30 min,电解结束后搅拌时间为20 min,此条件下出水残余Sr~(2+)为0.264 mg/L。在最佳工艺条件下,经XRD分析沉渣为Mn3O4。整个电解过程符合零级动力学,拟合动力学方程为ct=c0-0.159 1t。     

果胶-PDA微球的功能化制备及其对Th~(4+)的吸附性能

以果胶为原料,利用溶胶-凝胶法,Ca~(2+)为交联剂制备出果胶-Ca微球,使用多巴胺修饰果胶-Ca微球生成功能化的吸附剂果胶-聚多巴胺(PDA)微球。探讨了该吸附剂去除Th~(4+)的吸附性能,并利用SEM、FTIR和XPS分析了其功能化制备和吸附的机理。结果表明,果胶-PDA微球在pH=3.5时吸附效果最好,在25℃、pH=3.5、初始Th~(4+)质量浓度为24mg/L、吸附剂质量为0.03g的条件下,接触时间为1200min时,吸附容量可达到37.172mg/g;共存离子Cs+、Sr~(2+)、Mn~(2+)和Mg~(2+)对Th~(4+)的吸附影响较小,说明该吸附剂对Th~(4+)的吸附选择性较好;热力学和动力学研究结果表明,吸附过程符合线性Langmuir等温吸附模型和准二级动力学模型,最大吸附量为99.010 mg/g;热力学数据表明,果胶-PDA吸附Th~(4+)是一个自发吸热的过程;TG分析可知,果胶-PDA的热稳定性较改性前果胶-Ca有所提高;果胶-PDA上的N、O与溶液中Th~(4+)发生的螯合作用是果胶-PDA微球对Th~(4+)的主要吸附机理。     

表面活性剂改性的4A分子筛对氨氮的吸附行为

用表面活性剂十六烷基三甲基溴化铵(CTAB)和十二烷基苯磺酸钠(LAS)改性4A分子筛,利用X射线衍射和红外吸收光谱表征了改性前后4A分子筛的结构,并研究了其对氨氮的吸附行为。结果表明,两种表面活性剂的添加均能在一定程度上提高4A分子筛吸附氨氮性能,CTAB的改性效果优于LAS,且当两种表面活性剂m(CTAB)∶m(LAS)=10时复配效果最佳。此外,分别采用准一级动力学方程、准二级动力学方程和颗粒内扩散方程对改性4A分子筛吸附氨氮行为进行拟合。结果显示改性前后4A分子筛对氨氮的吸附过程可用Langmuir吸附等温方程较好地拟合,在温度为25℃时,单分子层饱和吸附量分别为5.61 mg/g和6.15 mg/g,其吸附动力学较符合准二级反应动力学方程。     

表面活性剂改性的4A分子筛对氨氮的吸附行为

用表面活性剂十六烷基三甲基溴化铵(CTAB)和十二烷基苯磺酸钠(LAS)改性4A分子筛,利用X射线衍射和红外吸收光谱表征了改性前后4A分子筛的结构,并研究了其对氨氮的吸附行为。结果表明,两种表面活性剂的添加均能在一定程度上提高4A分子筛吸附氨氮性能,CTAB的改性效果优于LAS,且当两种表面活性剂m(CTAB)∶m(LAS)=10时复配效果最佳。此外,分别采用准一级动力学方程、准二级动力学方程和颗粒内扩散方程对改性4A分子筛吸附氨氮行为进行拟合。结果显示改性前后4A分子筛对氨氮的吸附过程可用Langmuir吸附等温方程较好地拟合,在温度为25℃时,单分子层饱和吸附量分别为5.61 mg/g和6.15 mg/g,其吸附动力学较符合准二级反应动力学方程。     

海藻酸铜复合凝胶球对铅和汞溶液的吸附性能研究

海藻酸盐凝胶球是一类高效、廉价的吸附材料。将海藻酸钠与无毒环保的金属阳离子(Cu~(2+))混合可发生固化反应,可得到不溶于水的具有三维网络结构的聚合物水凝胶:SA-Cu,再与氧化乙烯、活性炭,分子筛形成复合凝胶球SA-Cu-PEO,SA-Cu-PEO-AC和SA-Cu-PEO-4AZ,用于处理水溶液中高浓度的Pb~(2+)和低浓度的Hg~(2+)。在实验条件下,四种复合物凝胶球对Pb~(2+)和Hg~(2+)均表现了优异的去除效果。包埋4A分子筛或活性炭均可以显著提高对两种重金属离子的吸附效果,其中包埋4A分子筛的凝胶球对Pb~(2+)的去除率可以达到98.6%,包埋4A分子筛的凝胶球对Hg~(2+)的去除率达到87%。此类水凝胶材料在水处理领域具有广阔的研究价值和应用前景。     

硅沸石—1制备方法改进及性能研究

本文阐述了一种制备憎水性分子筛—硅沸石-1的新工艺。测定了这种分子筛气相吸附正己烷、乙醇和水的平衡量,以及液相吸附乙醇和水的平衡量,表明这种分子筛具有良好的亲有机和憎水的吸附性能。通过液相吸附透过曲线实验,表明液相吸附乙醇过程为固膜扩散控制。经Cu~(2+)浸渍的这种分子筛,可使甲醇脱氢制甲醛的转化率的选择性大为提高。     

改性MCM-22分子筛吸附脱除油品中二氯甲烷的研究

采用离子交换法制备了不同金属离子(Ni2+、Co2+、Fe3+)改性的MCM-22分子筛。采用XRD、NH3-TPD和BET对吸附剂进行了表征,同时,考察了MCM-22分子筛经不同金属离子改性后作为吸附剂对模型化合物的脱氯性能,优化了吸附剂的活化条件,并在吸附试验中研究了最优吸附剂吸附二氯甲烷的动力学和吸附活化能。结果表明,吸附剂的最优活化温度及时间分别为450℃和4 h。脱氯效果顺序为:Ni MCM-22Co MCM-22Fe MCM-22MCM-22,最优吸附剂Ni MCM-22分子筛上吸附动力学可用拟二级动力学进行较好的描述,吸附过程以化学吸附为主。     

生物陶吸附Cd~(2+)性能研究

研究了1种生物陶吸附Cd~(2+)的优化条件,并以吸附动力学和热力学探讨吸附机理。结果表明,生物陶吸附Cd~(2+)的优化条件为:溶液温度为293.15 K,生物陶投加量为1 g/L,溶液初始p H为5.5,吸附在31 h内达到平衡,溶液中Cd~(2+)的去除率为95.30%;准1级动力学模型更准确的反映了生物陶吸附Cd~(2+)的吸附动力学;Freundlich模型比Langmuir模型更好的描述生物陶吸附Cd~(2+)的等温吸附行为,该吸附过程受颗粒内扩散、液膜扩散等步骤控制;Gibbs自由能变ΔG~θ0、焓变ΔH~θ0、熵变ΔS~θ0,表明Cd~(2+)在生物陶上的吸附为自发的、吸热的、趋于无序的吸附过程。     

鲤鱼肉骨生物炭的制备及其吸附水中Pb~(2+)特性

以水产养殖固体废弃物病死鲤鱼为生物质原材料,采用限氧裂解技术在600℃条件下制备鲤鱼肉骨生物炭(CMBB),探究了CMBB对水中Pb~(2+)的吸附特性,并对CMBB的结构和性质进行了表征。结果表明,CMBB表面具有不规则的中孔和微孔结构,表面带有大量的负电荷。CMBB对Pb~(2+)的吸附在4 h内达到平衡,动力学过程符合准2级动力学模型;吸附速率受内扩散机制控制,但并非唯一的控制机制;Pb~(2+)在CMBB上的等温吸附过程符合Langmuir、Langmuir-Freundlich和Temkin等温吸附模型,属于有利吸附;吸附过程为自发进行的熵增吸热过程。CMBB能够在较宽的pH范围(2～6)对Pb~(2+)具有明显的去除效果(去除率大于99%)。     

改性膨润土对刚果红的吸附动力学及热力学研究

制备了十六烷基三甲基溴化铵(CTAB)改性膨润土,利用红外光谱和XRD对其结构进行了表征,考察了投加量和pH值对吸附性能的影响.结果表明: CTAB能插入膨润土层间;当投加量为4 g/L,pH值为4时,去除率最高达97.15%.改性膨润土对刚果红的吸附符合准二级动力学方程和Langmuir等温吸附方程,由吸附热力学方程计算得到的吸附焓变(ΔH)<0,吸附自由能变(ΔG)<0,吸附熵变(ΔS)<0,表明吸附为放热和熵减少的自发过程.     

Studies on castor seed shell as a sorbent in basic dye contaminated wastewater remediation

The potentialities of castor seed shell (CSS), a waste agricultural by-product, in the remediation of water, contaminated with Methylene Blue (MB), a basic dye, were investigated in the present study. The CSS was ground and washed, thoroughly, to remove any water extractable constituents. The dried CSS was reground, sieved and used in series of agitated batch adsorption experiments. The experiments were conducted to assess the effect of two process variables i.e. initial MB concentration and CSS dosage on the sorption process. The equilibrium sorption isotherm was studied using the two widely used isotherm models (i.e. Freundlich and Langmuir isotherm models). The results from the isotherm studies showed that the process of sorption of MB occurred on a heterogeneous surface of the CSS. The sorption capacity of the CSS, as obtained from the Langmuir plot was 158 mg/g. The mass transfer property of the sorption process was studied using Lagergren pseudo-first-order and chemisorptions pseudo-secondorder kinetic models. The sorption process obeyed the pseudo-second-order kinetic model more than the pseudo-first order; hence the mechanism of the sorption process was analysed further using this kinetic model. The application of the intraparticle diffusion model to determine the rate limiting step showed that intraparticle diffusion is not the singular rate limiting step in the sorption of MB onto CSS. The role of chemisorptions in the mechanism of sorption was established by an empirical relationship between the pseudo-second-order rate constant, K, and the initial MB concentration. The results of this relationship showed that pseudo-second-order chemisorptions are important in the sorption process.     

层迭灵芝子实体及其制备炭吸附Cd2+的研究

以大型真菌层迭灵芝（Ganoderma lobatum）子实体及制备炭作为吸附材料用于吸附Cd²⁺,研究了吸附剂用量、初始pH值、反应时间、初始Cd²⁺质量浓度对吸附的影响。结果表明,当Cd²⁺质量浓度为10 mg/L时,层迭灵芝子实体及制备炭吸附Cd²⁺的最佳条件为吸附剂用量0.2 g,pH值为7,吸附时间为480 min,在此条件下Cd²⁺最大去除率分别为94.50%和92.75%。子实体对Cd²⁺的吸附速率显著高于制备炭,但子实体和制备炭吸附Cd²⁺的吸附能力之间无显著差异。采用Langmuir和Freundlich等温吸附模型研究子实体和制备炭吸附Cd²⁺的过程,子实体对Cd²⁺的吸附过程符合Freundlich模型,而制备炭更符合Langmuir模型。吸附动力学研究表明子实体和制备炭对Cd²⁺的吸附过程均符合准二级动力学模型。     

Synthesis of a novel functional group-bridged magnetized bentonite adsorbent:Characterization,kinetics, isotherm,thermodynamics and regeneration

A novel magnetic adsorbent was synthesized by magnetizing bentonite by APTES-Fe_3O_4 via a functional groupbridged interaction. The characterization of APTES-Fe_3O_4/bentonite was conducted via transmission electron microscope(TEM), X-ray diffraction(XRD), Fourier transform infrared spectrophotometer(FT-IR), thermal gravimetric analysis(TGA), vibrating sample magnetometer(VSM), zeta potential analysis and Brunner–Emmet–Teller(BET). The APTES-Fe_3O_4/bentonite was assessed as adsorbents for methylene blue(MB) with a high adsorption capacity(91.83 mg·g~(-1)). Factors affecting the adsorption of MB(such as p H, equilibrium time, temperature and initial concentration) were investigated. The adsorption process completely reaches equilibrium after 120 min and the maximum sorption is achieved at p H 8.0. The adsorption trend follows the pseudosecond order kinetics model. The adsorption data gives good fits with Langmuir isotherm model. The parameter factor RLfalls between 0 and 1, indicating the adsorption of MB is favorable. The adsorption process is endothermic with positive ΔH~0 values. The positive values of ΔG~0 confirm the affinity of the adsorbent towards MB, and suggest an increased randomness at the solid–liquid interface during the adsorption process. Regeneration of the saturated adsorbent was easily carried out via gamma-irradiation.     

活性碳纤维对水中喹啉的吸附性能

采用活性碳纤维（activated carbon fiber,ACF）静态吸附模拟废水中的喹啉,考察了吸附时间、喹啉初始浓度、温度、pH值、有机物等对吸附速率与吸附行为的影响。结果表明,ACF对喹啉的吸附速率快,30 min内基本达到平衡,初始浓度较高时,最终吸附容量较大,达210 mg/g,低温和pH值小于7时,吸附效果较好,苯酚与喹啉产生竞争吸附,配水中的吸附行为能较好的符合Langmuir等温方程,吸附动力学符合准二级动力学模型,热力学参数ΔH0、ΔG0为负值,表明该吸附是一个自发的放热过程。本研究为环境功能材料ACF应用于工业化生产提供了理论依据,有必要在此基础上进行动态吸附实验以及实际焦化废水的吸附处理实验,同时ACF成本高及脱附再生等方面问题还有待进一步深入研究。     

Characteristics of Amine Surfactant Modified Peanut Shell and Its Sorption Property for Cr（VI）

Modified peanut shell （MPS） was prepared by amination reaction with peanut shell （PS） as the starting material The sorption of Cr（VI） oxyanions on MPS in static and column tests were investigated. In addition, the sorption isotherm and kinetic models were applied to confirm the sorption capacity and the sorption mechanisms. BET surface area anysis showed the physicochemical characterist!cs of the samples. The results of zeta potential,Fourier transform infrared （FT-IR） and Raman spectra analysis illustrated that chemical adsorption and ion exi change are the potential sorption mechanism. The static sorption test showed that the maximum sorption capacity （qm） of MPS for Cr（VI） increased with temperature, which indicated that the Cr（VI） sorption rocess was endothermic. The saturated sorption capacity of Cr（VI） in the colunm sorption test was 138.34 mg.g-1, which accounted for 93.9% of the qmax at 25 ℃. The regeneration capacity of MPS was evaluated using HC1 solution as an eluent. The high regeneration efficiency （82.6%） validated the dominance of the ion exchange mechanism in the Cr（VI） sorption process with C1ions displacing Cr（VI） oxyanion on MPS. The Langmuir isotherm model showed a higher correlation coefficient than the other adsorption isotherm models. And in the kinetic study, a pseudo-second-order model fit the data best.     

磁性胺肟基功能化CMC对铀酰离子的吸附行为研究

采用两步法合成磁性胺肟基功能化CMC（简称PAO/CMC/Fe3O4）,用批示法研究了PAO/CMC/Fe3O4对U（Ⅵ）的吸附行为,考察了pH值、吸附时间、吸附剂用量等对吸附效果的影响.结果表明,PAO/CMC/Fe3 O4对U（Ⅵ）的吸附容量大,速度快,最大吸附容量119.21 mg/g,30 min左右达到吸附平衡,平衡数据符合Langmuir等温方程,符合伪二阶动力学吸附模型,说明PAO/CMC/Fe3O4对U（Ⅵ）的化学吸附过程是速率控制步骤.     

Dowex50W-X树脂吸附硫酸溶液中的锶

In this study,strontium adsorption from sulfuric acid solution by different Dowex 50W-X ion exchange resins was investigated.Among these resins,Dowex 50W-X8 resin showed the maximum sorption of strontium from the aqueous solutions.The effect of pH,contact time,mass of resin,temperature,and concentration of interfering ions on strontium adsorption were evaluated to determine the optimum conditions of strontium sorption process.The kinetic models of sorption were analyzed using pseudo-first and pseudo-second order models.The results indicated that the pseudo-second order kinetic model was more appropriate than the other one.Moreover,the data obtained in this study were fitted into several sorption isotherm models and it was found that the Langmuir sorption isotherm shows the best fitting to the experimental data.     

竹炭对铜（Ⅱ）吸附的热力学和动力学参数的研究

研究了竹炭对水相中铜（Ⅱ）吸附的动力学和热力学参数。动力学研究表明：竹炭对铜（Ⅱ）的吸附拟用准一级动力学处理,动力学方程可表示为-1n（1-F）=k1,弗测定不同粒径、不同温度下竹炭对铜（Ⅱ）吸附的表观速率常数及活化能。热力学研究表明：竹炭对铜（Ⅱ）的吸附的焓变△H=-22．6kJ／mol,说明竹炭吸附过程为放热过程,且△H〈40kJ／mol,表明吸附过程主要为物理吸附。同时测得吉布斯自由能△G〈0,且受温度的影响不大,表明吸附质从溶液到吸附剂表面的吸附过程是自发过程。     

Sorption of cobalt to bone char: Kinetics, competitive sorption and mechanism

Swine bone char is the combustion residues of swine bone. Cobalt adsorption to swine bone char was studied. Batch kinetics studies showed that a rapid uptake occurred during the first 5 min and was followed with a very slow intraparticle diffusion process. The sorption kinetics was ideally conformed to pseudo-second equation, indicating several mechanisms involved in the adsorption process. Equilibrium sorption isotherm studies showed that the Freundlich isotherm model satisfactorily described the sorption data. The presence of co-ions had appreciable inhibiting effects on cobalt uptake by bone char because copper and zinc had higher affinity for the bone char surface than cobalt. Calcium concentration in solution and XRD analysis showed that ion exchange was involved in the removal of Co from solution over a certain initial cobalt concentration range.