改性活性炭吸附污水中氨氮的性能

采用浸渍法制备一系列过渡金属(Zn,Fe,Cu)改性活性炭吸附剂,并探讨其吸附污水中氨氮的性能。结果表明,过渡金属的添加能在一定程度上提高活性炭吸附氨氮性能,其中铜为最佳改性元素。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活性炭吸附氨氮行为进行拟合。结果显示改活性炭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为7.19 mg/g,其吸附动力学较符合准二级反应动力学方程。     

改性硅藻土对氨氮的吸附行为

用过渡金属(Fe、Cu、Zn)改性硅藻土,利用红外吸收光谱(IR)表征了改性前后硅藻土的结构,并研究了其对氨氮的吸附行为。结果表明,Fe的添加能在一定程度上提高硅藻土吸附氨氮性能。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硅藻土吸附氨氮行为进行拟合。结果显示,改性硅藻土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为8.11 mg/g,其吸附动力学较符合准二级反应动力学方程。     

改性硅藻土对氨氮的吸附行为

用过渡金属(Fe、Cu、Zn)改性硅藻土,利用红外吸收光谱(IR)表征了改性前后硅藻土的结构,并研究了其对氨氮的吸附行为。结果表明,Fe的添加能在一定程度上提高硅藻土吸附氨氮性能。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硅藻土吸附氨氮行为进行拟合。结果显示,改性硅藻土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为8.11 mg/g,其吸附动力学较符合准二级反应动力学方程。     

碳酸钾改性油茶壳活性炭吸附水中氨氮的研究

利用所制备的油茶壳活性炭对水体中的氨氮进行了吸附,探讨了各因素对吸附效果的影响,并进行了吸附热力学和动力学分析。结果表明:活化温度及活化剂浓度的提高有利于油茶壳活性炭对氨氮的吸附。吸附过程在420 min左右达到平衡,符合准二级动力学模型。吸附过程符合Langmuir等温吸附模型,对氨氮的最大吸附量可达到10.83 mg/g。在最适的实验条件下,0.1 g的碳酸钾改性油茶壳活性炭对初始质量浓度为20 mg/L的氨氮废水中氨氮的去除率可以达到50.3%,吸附效果良好。     

柚皮活性炭对氨氮吸附性能研究

采用氯化锌活化法制备柚皮活性炭,探讨其对废水中氨氮的吸附性能.结果表明,在pH为2～12,温度为30～50℃条件下,柚皮活性炭对氨氮均能取得较好的吸附效果;相同氨氮初始浓度条件下,随着投加量增加,单位质量柚皮活性炭对氨氮的吸附量明显减少;初始氨氮浓度越大,氨氮吸附量也越大.吸附数值遵循Henry及Freundlich等温吸附模型,吸附过程符合准二级动力学方程.     

4A分子筛改性催化剂制备及其吸附氨氮的性能

分别采用过渡金属(Fe,Zn,Cr,Cu)、盐酸、氢氧化钠以及十二烷基硫酸钠(SDS)对4A分子筛改性,并测其吸附污水中氨氮性能。结果表明,Fe和SDS协同改性的4A分子筛去除氨氮性能最佳,在25℃时,单分子层饱和吸附量为3.20 mg/g,其吸附动力学符合准二级反应动力学方程。     

4A分子筛改性催化剂制备及其吸附氨氮的性能

分别采用过渡金属(Fe,Zn,Cr,Cu)、盐酸、氢氧化钠以及十二烷基硫酸钠(SDS)对4A分子筛改性,并测其吸附污水中氨氮性能。结果表明,Fe和SDS协同改性的4A分子筛去除氨氮性能最佳,在25℃时,单分子层饱和吸附量为3.20 mg/g,其吸附动力学符合准二级反应动力学方程。     

改性活性炭在微波场中升温性能的研究

通过浸渍法制备负载Cu~(2+)、Fe~(3+)和Co~(2+)等过渡金属离子的改性活性炭。以N_2作为保护气,在微波场中进行升温实验,通过与未经改性处理的活性炭进行比较,发现负载金属离子的活性炭在微波场中具有更高的升温速率和温度最大值。经过微波辐照之后,改性活性炭的质量损耗率在7%以下。     

给水厂污泥改性活性炭对硝酸根的吸附性能

对原始活性炭和水厂污泥提取的金属改性的活性炭吸附硝酸盐氮的性能进行了探究。X射线荧光光谱仪(XRF)分析表明,活性炭表面负载了Al、Fe等元素,Fe的负载量为4.61 mg/g, Al的负载量为13.80 mg/g,改性后活性炭比表面积有所下降。改性活性炭对硝酸盐氮的吸附过程符合准二级动力学方程,Langmuir吸附等温式在288 K时,改性活性炭对硝酸盐氮的吸附量为2.752 5 mg/g,改性活性炭对硝酸盐的吸附过程是熵增和放热的自发反应。在酸性和中性条件下,改性活性炭对硝酸盐的吸附效果较好。     

改性膨润土对氨氮废水吸附性能的研究

用内蒙膨润土及其碱改性膨润土进行模拟氨氮废水的脱氮实验研究。结果表明,在氨氮溶液初始浓度为300 mg/L,pH值为3.0～7.0时,相对于天然膨润土,碱改性膨润土对氨氮的吸附量有了很大提高,其吸附等温线符合Freundlich和Langmuir方程,且对氨氮的吸附动力学符合准一级和准二级吸附动力学模型,说明化学吸附和物理吸附共同起作用;在应用于畜禽废水处理中,碱改性膨润土对氨氮去除率达到91.0%。     

聚甲基丙烯酸改性活性炭的制备及其吸附高氯酸铵的研究

通过表面引发接枝聚合将甲基丙烯酸接枝聚合到活性炭表面,用于处理高氯酸铵污染水的研究。结果表明,改性活性炭吸水率明显提高,高氯酸铵吸附量2. 28 mg/g,吸附平衡时间10 min。与活性炭相比,吸附量提高了2. 2倍,吸附平衡时间降低了60%。     

The role of water and surface acidity on the reactive adsorption of ammonia on modified activated carbons

Commercial carbons were modified by incipient wetness impregnation with aqueous solutions of metal salts (Fe, Co, Cr), followed by calcinations at low temperature (300 °C). The materials were characterized using adsorption of nitrogen, potentiometric titration, thermal analysis, XRF, SEM and FTIR. Their performance for ammonia removal was evaluated in dynamic conditions at room temperature. The results indicate that activated carbons with supported metals on the surface can be used for the removal of ammonia pollution and their capacity depends on the nature of the metal deposit and its acidity. Moreover the capacity is also affected by the presence of moisture and surface functional groups. The latter, when strongly acidic, significantly enhance the adsorption capacity. On the surface of modified activated carbons reactive adsorption of ammonia takes place via the formation of ions, which bind to surface acidic groups. Thus the removal process is essentially governed by acid-base interactions.     

The adsorption properties of surface modified activated carbon fibers for hydrogen storages

In this study, activated carbon fibers (ACFs) with high surface area and pore volume have been modified by Ni doping and fluorination. The surface modified ACFs were characterized by BET surface area, SEM/EDS, XRD, and Raman spectroscopy. The changes in pore structure and surface properties of these modified ACFs were correlated with hydrogen storage capabilities. After fluorination treatment, although the micropore volume of ACF was decreased, amounts of hydrogen storage were found to increase. Additionally, micropore volume on ACFs was found to be unchanged with Ni doping, hydrogen storage capacities were considerably increased due to the effect of catalytic activation of nickel. Though fluorination of ACFs increases hydrogen affinity, the effect of catalytic activation of nickel is more prominent, and thus led to better hydrogen storage. Hence, it was concluded that hydrogen storage capacity was related to micropore volumes, Pore size distribution (PSD) and surface properties of ACFs as well as specific surface areas.     

Surface modified granular activated carbon for enhancement of nickel adsorption from aqueous solution

Coal-based granular activated carbon was modified with acetates of sodium, potassium and lithium at concentrations of 10 and 15% and used as adsorbents to explore the adsorption mechanism of nickel ion in aqueous solution. Acetate treatment reduced surface area and pore volume of the activated carbons, but the adsorption amount of Ni(II) on the modified activated carbons (MAC) was greater than that on the virgin activated carbon. The adsorption depended on pH of the solution with an optimum at 4.5 and the adsorbed nickel could be fully desorbed by using 0.05M HCl solution. The maximum adsorption capacity of nickel ion on Li (15 wt%) modified activated carbon was 151.3 mg/g and the adsorption isotherm follows Langmuir, Sips, and Redlich-Peterson isotherm models better than the Freundlich isotherm model. The kinetic data was better fitted by a non-linear form of the pseudo-first order than the pseudo-second order, but the difference between two kinetic models was small.     

Nitrogen and hydrogen adsorption of activated carbon fibers modified by fluorination

In this study, activated carbon fibers (ACFs) were surface modified with fluorine and mixed oxygen and fluorine gas to investigate the relationship between changes in surface properties by nitrogen and hydrogen adsorption capacity. The changes in surface properties of modified activated carbon fibers were investigated using X-ray photoelectron spectroscopy (XPS) and compared before and after surface treatment. The specific surface area and pore structures were characterized by the nitrogen adsorption isotherm at liquid nitrogen temperature. Hydrogen adsorption isotherms were obtained at 77 K and 1 bar by a volumetric method. The hydrogen adsorption capacity of fluorinated activated carbon fibers was the smallest of all samples. However, the bulk density in this sample was largest. This result could be explained by virial coefficients. The interaction of hydrogen-surface carbon increased with fluorination as the first virial coefficient. Also, the best fit adsorption model was found to explain the adsorption mechanism using a nonlinear curve fit. According to the goodness-of-fit, the Langmuir–Freundlich isotherm model was in good agreement with experimental data from this study.     

浸渍法改性活性炭纤维吸附一氧化氮的研究

采用不同浓度的硝酸铁溶液在不同的处理温度和时间下,浸渍聚丙烯腈基活性炭纤维(PANACF), 用正交实验法分析影响改性PAN-ACF吸附一氧化氮转化率的主要因素。实验结果表明,浸渍液的初 始浓度是影响一氧化氮吸附转化率的主要因素。在初始浓度为0.1-0.14mol／L时,吸附转化率达到最大 值70％左右,吸附温度和吸附时间对吸附转化率影响不大。通过扫描电镜观察,铁离子不规则分布在PANACF 表面。     

压块净水活性炭的孔结构与吸附特性

研究分析了利用太西无烟超低灰纯煤生产的压块净水活性炭的技术指标、孔结构特征及其吸附特性;该活性炭内部以两种孔径范围的微孔为主,BET表面积高达764.83 m2/g,在P/P0为0.30时最大比表面积为809.776 m2/g,最大孔容积为0.412 cm3/g,是一种灰分低、强度高、吸附性能优良的净水活性炭。