石墨烯的制备及其对甲苯的吸附性能

为了寻求高效的有机废气吸附剂,用氧化石墨还原法制取石墨烯进行吸附。选取挥发性有机气体中的甲苯作为研究对象,用石墨烯作为吸附材料,分别考察了床层高度、吸附温度及甲苯初始质量浓度对石墨烯吸附甲苯性能的影响。结果表明,石墨烯吸附甲苯容量与甲苯初始质量浓度、床层高度、温度成正比。在实验温度25℃、床层高度10mm及气速200mL/min条件下,甲苯吸附量为100mg/g。石墨烯吸附甲苯的动力学过程符合假二级动力学模型,吸附等温线拟合符合Freundlich模型。     

改性半焦对苯酚吸附性能的研究

采用活化处理及碱处理的方法对半焦进行改性,并用于吸附苯酚研究。考察了吸附温度、时间、苯酚溶液初始浓度以及改性半焦用量等因素对改性半焦吸附苯酚过程的影响。结果表明,当吸附温度20℃,苯酚溶液初始浓度100mg/g,改性半焦质量20mg,吸附时间60min,改性半焦对苯酚的平衡吸附量为23.69mg/g。动力学研究表明准二级动力学方程能很好地拟合该吸附过程,吸附平衡研究表明该吸附过程符合Freundlich模型。     

AgY分子筛的制备及其吸附脱除模拟燃料中吡啶的性能

采用离子交换法制备了AgY分子筛,利用X射线衍射对AgY分子筛进行了表征,并分别以NaY和AgY分子筛为吸附剂进行模拟燃料中吡啶的静态吸附脱除试验。结果表明,AgY分子筛的吸附脱氮能力强于NaY分子筛,且AgY分子筛较适宜的吸附脱氮条件为：当模拟燃料用量为15 mL时,分子筛用量0.2 g、吸附温度333 K、吸附时间40 min。采用Materials Studio软件建立了NaY和AgY分子筛团簇模型,模拟计算了吡啶分子在NaY和AgY分子筛团簇上的吸附能及其与活性中心的距离,结果表明,吡啶与AgY分子筛活性中心的距离小于NaY分子筛,故AgY分子筛的吸附性能好于NaY分子筛。吸附等温线研究结果表明,AgY分子筛对模拟燃料中吡啶的吸附行为符合Langmuir-Freundlich混合模型;吸附热力学和动力学研究结果表明,此吸附反应是自发进行的吸附熵增过程;在333 K温度条件下,此吸附过程符合准二级动力学模型。     

树枝状疏水缔合聚合物的吸附行为

以部分水解聚丙烯酰胺(HPAM)为对比,研究了溶液浓度、接触时间、石英砂颗粒粒径对树枝状聚合物DHAP溶液吸附量的影响.结果表明:HPAM符合Langmuir等温线吸附和准二级吸附动力学,在石英砂表面进行化学吸附,具有稳定的单分子层吸附特征,单位面积的平衡吸附量为1.17～1.62μg/cm2;树枝状聚合物DHAP符合Langmuir等温线吸附、准二级吸附动力学和Elovich模型,在石英砂上的单位面积吸附量为6.44～8.45μg/cm2.树枝状聚合物D H A P的吸附机理包括以氢键、静电作用等在石英砂表面所产生的一级化学吸附、分子间缔合作用影响下的二级缠绕、树枝状结构的空间展布扩宽吸附层厚度.     

油酸二乙醇酰胺对润滑油在水-土体系中吸附行为的影响

采用振荡平衡法对含油酸二乙醇酰胺(简称ODEA)润滑油在水-土体系中的吸附行为进行研究,考察在水-土体系中含ODEA润滑油的吸附动力学特征及其吸附等温线。结果表明:润滑油及含ODEA润滑油均能较快地被土壤吸附,吸附动力学曲线符合Lagergren伪二级动力学方程,吸附等温线符合Freundlich和Henry吸附等温模型;ODEA可以抑制润滑油在土壤中的吸附量和吸附速率,当ODEA质量浓度为4 mg/L时,抑制吸附效果最为显著。     

ZSM-5分子筛脱除模拟燃料中苯胺或吡啶的吸附行为

研究了不同硅铝比分子筛(记作ZSM-5(1)～ZSM-5(4))吸附脱除模拟燃料中苯胺或吡啶的脱氮性能,以及ZSM-5(2)在温度分别为303,323,343 K时对苯胺或吡啶的吸附等温线和动力学。实验结果表明,硅铝比较小的ZSM-5(1)与ZSM-5(2)吸附脱除苯胺或吡啶效果均明显优于其他试样,并且所有试样吸附脱除吡啶的效果均优于苯胺;ZSM-5(2)吸附苯胺或吡啶的吸附等温线的拟合结果比较符合Langmuir-Freundlich混合模型,吸附苯胺符合准二级动力学方程,吸附吡啶符合准一级动力学方程。     

树脂去除压裂返排液中残余硼的实验研究

硼交联剂在压裂液体系中具有重要作用,残余硼对压裂返排液的再次回用具有强制约性,会直接影响配液性能。针对压裂返排液除硼这一技术难题,以硼去除率为考察指标,采用硼螯合树脂从吸附时间、温度、pH值、转速、树脂用量、树脂再生次数等方面考察树脂对硼的吸附效果,并分析离子强度对吸附性能的影响,确定吸附动力学模型和吸附机理。结果表明:最佳树脂除硼工艺为吸附时间1 h、温度25℃、pH值9、转速200 r/min、树脂用量2.5 g,此时硼的平均去除率为94.85%,满足重新配液要求;不同二价离子强度对树脂吸附的影响作用有限;树脂吸附过程符合准二级动力学模型和Freundlich等温吸附模型,以单分子层化学吸附为主;分别采用清水和处理后的压裂返排液配置压裂液,两者的挑挂性能无差别。此研究结果可为提高压裂返排液的回用效果提供技术支撑。     

HKUST-1金属有机骨架材料对水溶液中稀土离子的选择性吸附

在水热条件下合成了铜基金属有机骨架材料(HKUST-1),以稀土离子为吸附对象,研究了HKUST-1吸附前后理化性质的变化规律,得到其吸附动力学方程的拟合曲线。结果表明：在25℃和pH=6条件下,HKUST-1对铈离子(Ce³⁺)和镧离子(La³⁺)的最大吸附量分别为234和203 mg/g;在金属离子混合溶液中,对稀土离子(Ce³⁺和La³⁺)的选择性达到87%;吸附过程符合准二级动力学模型。再生后的HKUST-1（HKUST-1-R）对稀土离子的吸附量下降显著,说明HKUST-1吸附稀土离子的过程不仅有离子交换反应,还有络合配位反应。     

介孔碳及其铁改性材料吸附水中对硝基苯酚

采用水热合成法以F127为模板剂制备介孔碳材料（MC）,一步合成法引入Fe(NO ₃ ) ₃ •9H₂O得到铁改性介孔碳材料（Fe/MC-x,x为合成原料中铁源与间苯二酚的摩尔比,x=0.5、1、1.5）,对改性前后的材料进行TEM、N₂吸-脱附、XRD及FI-TR表征,通过考察吸附剂量、吸附等温线、吸附动力学对其吸附水中对硝基苯酚（p-NP）进行了研究。结果表明,所得MC和Fe/MC-x的孔径分布集中于3~4 nm,比表面积分别为643.6、635.6、636.0和587.2m²/g。实验条件下,Fe/MC-x的吸附性能优于MC,其中Fe/MC-1.0有最大吸附量220.35 mg/g,对应去除率为92.33%;平衡吸附量均与初始浓度呈正相关,与吸附剂投加量呈负相关,高温不利于吸附,P-NP在MC和MC-x上的吸附行为符合Freundlich模型;改性行为加快了吸附速率,吸附过程符合准二级动力学模型,主要为化学吸附控制吸附速率。     

微波-超声波联合再生活性炭及其用于处理含酚废水

利用微波-超声波联合工艺对吸附饱和的活性炭进行再生处理,并以苯酚溶液为含酚废水模型,采用正交实验探讨了微波、超声波功率和时间对活性炭再生效果的影响。实验结果表明,对活性炭再生的影响因素大小顺序为;微波功率>超声波功率>反应时间;在适宜的再生条件下(微波功率400 W、超声波功率200 W、反应时间4 min),活性炭再生效率可达95.8%。研究了再生处理前后的活性炭对苯酚的吸附行为,再生前的吸附行为符合Langmuir等温吸附模型,饱和吸附量为156.6 mg/g;再生后的吸附行为符合Freundlich等温吸附模型,为多层吸附。经微波-超声波联合工艺处理的再生活性炭对苯酚的吸附效率比单独使用微波或超声波处理分别提高了35%和200%。     

Effective biosorption of patulin from apple juice by cross-linked xanthated chitosan resin

In this work, cross-linked xanthated chitosan resin (CXCR) was prepared by inverse suspension cross-linking method, using glutaraldehyde as cross-linking agent and carbon disulfide as modification agent. The biosorption of CXCR for patulin from apple juice was investigated. Batch adsorption experiments were performed to evaluate the effect of pH, temperature, contact time and initial concentration. The adsorption of CXCR for patulin was characterized by Fourier Transform Infrared Spectroscopy (FTIR). The results showed that the optimum adsorption conditions of CXCR for patulin was achieved at pH 4, 30 °C for 18 h. The adsorption data could be fitted with pseudo–second order kinetic model and Freundlich isotherm model. It indicated that CXCR is an appropriate adsorbent for the removal of patulin from apple juice.     

含有机模板剂的ZSM-5对水中铜离子的吸附

以1,6 己二胺(HMD)为模板剂,由麦羟硅钠石转晶制备的ZSM 5沸石分子筛在模板剂未被烧除的情况下对水中铜离子(Cu2+)有良好的吸附作用,并从溶液化学角度如：吸附时间、pH值、温度等方面,考察了含有HMD的ZSM 5沸石分子筛对水溶液中Cu2+的吸附行为。 结果表明,以HMD为模板剂的ZSM 5分子筛对水中Cu2+的吸附在pH=6的条件下吸附容量最大;由Langmuir模型计算出当Cu2+水溶液pH=6、温度为318 K时,HMD为模板剂的ZSM 5沸石分子筛对Cu2+的最大吸附量为8696 mg/g;热力学数据表明,HMD为模板剂的ZSM 5沸石分子筛对Cu2+的吸附行为是吸热、自发的过程;动力学数据表明,该过程符合准二级动力学方程,属于物理吸附过程。HMD为模板剂的ZSM 5沸石分子筛可以作为一种新型吸附剂。     

介孔SBA-15分子筛对苯酚的吸附性能

针对废水中苯酚的脱除,研究了硅基介孔分子筛SBA-15对苯酚的吸附,并与活性炭进行了对比;采用XRD和N2吸附-脱附法对SBA-15分子筛和活性炭进行了表征。与活性炭相比,SBA-15分子筛的比表面积虽小,但其具有丰富的介孔,使其达到吸附平衡所用的时间较短且饱和吸附量较大。SBA-15分子筛对苯酚的吸附可用Langmuir和Freundlich等温吸附方程描述,其中Langmuir等温吸附方程具有更好的相关性。分别采用拟一级和拟二级反应模型考察了SBA-15分子筛对苯酚的吸附动力学,拟二级反应模型与实验数据之间有很好的相关性。热力学参数的计算结果表明,SBA-15分子筛对苯酚的吸附过程是放热和自发的过程,且以物理吸附为主。     

Preparation and characterization of sulfonated polystyrene/magnetite nanocomposites for organic dye adsorption

Magnetite nanoparticles (MNPs) were prepared by co-precipitation method and were found to have average size of 5 nm with spherical shape crystalline structure with super-magnetic properties. Commercial polystyrene (PS) was sulfonated through the reaction with freshly prepared acetyl sulfate. Three different degrees of sulfonation, based on the ratio of the acetyl sulfate to polystyrene, were prepared (1:1, 1:3 and 1:5). Nanocomposites of the prepared magnetite nanoparticles 1:3 sulfonated polystyrene were prepared at different magnetite content (1, 5 and 10%). The produced materials were characterized by dynamic light scattering (DLS), transmittance electron microscope (TEM) X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). PS, MNPs and the prepared nanocomposites were investigated as adsorbents for Congo Red (CR). The variables influencing the adsorption capacity, such as solution pH, contact time and the initial dye concentration were systematically investigated. The adsorption for CR by the previous adsorbents show maximum experimental uptake capacity of 26.78, 33.15, 53.35, 64.73, and 76.29 mg/g for PS, MNPs, SPS/MNPs 1%, SPS/MNPs 5% and SPS/MNPs 10%, respectively. The adsorption process was found to follow the pseudo second order kinetic model and fit quite well with Langmuir adsorption isotherm.     

颗粒活性炭对地下水中溶解油的吸附特性

研究不同材质和粒径的颗粒活性炭对地下水中溶解油的吸附性能及影响因素,以确定最佳吸附条件。结果表明,颗粒活性炭对地下水中溶解油的吸附过程较好地符合Lagergren拟二级动力学方程,吸附平衡时间为300 min,椰壳制颗粒活性炭对溶解柴油和委内瑞拉原油的平衡吸附量分别为123.4 mg/g和26.81 mg/g,明显高于果壳和煤质制颗粒活性炭的平衡吸附量,且吸附量随颗粒活性炭粒径的减小而增大。吸附地下水中溶解柴油和原油的40～60目椰壳活性炭投加质量分别为0.1 g和0.06 g,吸附最佳温度是25 ℃,吸附柴油和原油的最佳pH值分别是7和8。盐度对于颗粒活性炭吸附溶解油的影响不大,碱性环境对于活性炭吸附柴油有明显的抑制作用,而酸性条件对于活性炭吸附原油有明显的抑制作用;颗粒活性炭对溶解柴油和原油的吸附分别适合Langmuir和Freundlich等温吸附模型,即颗粒活性炭表面对溶解柴油的吸附主要是单层吸附,而对溶解原油的吸附是非均匀异质的。     

双频超声波/过氧化氢工艺降解废水中苯酚的动力学研究

采用双频超声波(US/US)、过氧化氢(H2O2)和US/US/H2O2工艺处理含苯酚废水,研究了不同工艺对苯酚降解反应的影响。实验结果表明,在US/US,H2O2,US/US/H2O23种工艺条件下,苯酚降解均符合表观一级动力学。在苯酚初始质量浓度为100m g/L、溶液初始pH为5.0、反应液体积1L、H2O2用量250m g、温度30℃、处理时间90m in的条件下,采用US/US,H2O2,US/US/H2O2工艺,苯酚的去除率分别为62.8%,15.4%,98.7%,苯酚降解的速率常数增强因子可达到4.481。推导出了简化的苯酚降解反应动力学模型。     

Polyethylenimine-functionalized magnetic amorphous carbon fabricated from oil palm leaves as a novel adsorbent for Hg(II) from aqueous solutions

PEI (polyethylenimine) functionalized magnetic amorphous carbon thin film nano composite (Fe₃O₄-PEI-ACTF NC), was successfully synthesized and characterized by High Resolution Transmission Electron Microscope (HR-TEM), X-ray diffraction (XRD), Fourier-transform infrared spectrometer (FTIR), and Thermo gravimetric analysis (TGA). The synthesized nano composite Fe₃O₄-PEI-ACTF was developed as a highly efficient adsorbent for Hg(II) from aqueous samples. Effect of pH, contact time, adsorbent dose, initial concentration and temperature were investigated and optimized through batch adsorption technique. Besides, good magnetic performance of Fe₃O₄-PEI-ACTF NC makes it easily recovered from water with magnetic separation at low magnetic field. The adsorption kinetic data described well with the pseudo-second-order model and the equilibrium data fitted well to Langmuir isotherm model. The maximum adsorption capacity was 714?µg/g of Hg(II). Thermodynamic studies (ΔG°?<?0, ΔH°?>?0, ΔS°?>?0) implied an endothermic and spontaneous adsorption process in nature. Furthermore, the excellent reproducibility indicated that Fe₃O₄-PEI-ACTF NC has a promising application for removing heavy metals from aqueous environments due to high adsorption capacity and easily and quick separation.     

Kinetic and intraparticle diffusion studies of carbon nanotubes-titania for desulfurization of fuels

The authors report on the kinetics, pseudo first-order model, pseudo second-order model, and intraparticle diffusion mechanism. Thus, the experimental data of the adsorption of thiophene, benzothiophene, and dibenzothiophene on a material of carbon nanotubes-titania were fitted to the kinetics and intraparticle diffusion models. The kinetics parameters of qe and correlation coefficient indicated that the data are not fitted with the pseudo first-order model while they are well fitted to the pseudo second-order model with R² of more than 0.99 and the maximum adsorption capacities qe calculated from the pseudo second order model are in accordance with the experimental values for the three sulfur compounds in a model fuel. The results indicated that the adsorbent has a higher adsorption efficiency toward DBT over the other two sulfur compounds. Fitting the data to the intraparticle diffusion model indicated the intraparticle diffusion was not only rate-controlling step and hence it can be suggested that the surface adsorption and intraparticle diffusion were concurrently operating. The experimental results demonstrate that the combining of titania and carbon nanotubes is a promising material, which can be used in desulfurization.     

载银及酸处理改性对稻壳活性炭吸附脱硫性能的影响

将稻壳炭化后经KOH浸泡及焙烧活化制得稻壳活性炭,再利用超声波辅助AgNO3溶液浸渍及HNO3酸处理,制得改性稻壳活性炭。采用XRD、SEM、BET、FT IR等手段表征样品,利用含噻吩模拟油填充床实验,研究改性稻壳活性炭吸附脱硫性能,并利用吸附模型方程对吸附过程进行热力学及动力学分析。结果表明,AgNO3浸渍并焙烧后形成Ag微晶颗粒分散于活性炭表面,HNO3酸处理会增加活性炭表面酸性含氧官能团数量;改性后稻壳活性炭吸附脱硫能力增加,4种活性炭的吸附脱硫能力从大到小依次为Ag HNO3 AC、HNO3 AC、Ag AC、RH AC;Langmuir等温吸附模型、准n阶动力学吸附模型、Weber Morris内扩散模型能较好地说明改性稻壳活性炭吸附噻吩的作用机理。     

The decline of scale-forming ions from R.O feed water using kaolinite/nano-sized iron oxide composite

The study was designed to synthesize iron oxide-kaolinite composite to apply as a sorbent for a pre-treatment of seawater used as feed water in reverse osmosis units. Herein, we present kaolinite/Nano-sized iron oxide composite through the impregnation process. The morphologies of synthesized iron oxide and kaolinite-iron oxide nanocomposites were characterized by thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), zeta potential measurement (ZPM), scanning electron microscope (SEM) and X-ray diffraction as well as FTIR. The results indicated iron oxide was well dispersed on the surface of kaolinite. Kaolinite/iron oxide composite has been found particularly useful for adsorption of scale-forming ions from seawater. The parameters controlling the uptake of the scales ions from seawater are contact time, initial ions concentration, adsorption dose, temperature, and pH. The removal efficiency reached 84% for barium under certain conditions. The adsorption follows Pseudo 2nd order with a maximum adsorbent capacity of 2.2 mg g⁻¹. The pseudo-second order kinetic model was found to be the best model describing the process.