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%。     

改性球形活性炭对氨气吸附性能的研究

研究了不同金属盐溶液浸渍改性的球形活性炭对氨气的吸附性能以及同种浸渍剂的最佳浸渍比。采用扫描电镜、透射电镜、X射线衍射仪、康塔吸附仪探究了不同浸渍比对浸渍炭样品的表面形貌、物相结构及孔径分布的影响。通过固定床吸附装置对基炭和浸渍炭进行了氨气吸附性能的研究。结果表明：浸渍剂种类对氨气吸附效果有很大影响, 同等浸渍条件下, 氯化钴浸渍的活性炭具有最优氨气吸附效果, 氯化钴浸渍比为50%的样品对氨气的吸附量最高, 可达54.05 mg/mL, 为基炭的37倍。对吸附氨气后样品的物化性质进行分析以及程序升温脱附表征, 结果表明氯化钴与氨气反应生成了[Co（NH₃）₆]Cl₃。     

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%。     

改性活性碳纤维对苯胺吸附特性分析

开展了等离子体改性活性碳纤维对苯胺吸附性能的理论和实验研究。通过改变等离子体改性功率和改性时间,探寻最佳改性条件;采用BET、XPS、FTIR、热重测试对改性前后活性碳纤维理化特性进行了表征分析。结果表明,在等离子改性功率为22W,时间为3min时为最佳改性条件;改性后的活性碳纤维对水溶液中苯胺的去除率可达79.3%,去除率提高了8%。微观上等离子体改性使得活性碳纤维表面含氧官能团含量增加,增强对溶液中苯胺的吸附效果。吸附实验结果表明,改性前后活性碳纤维对苯胺的吸附在溶液pH为6时,吸附效果最佳;但达到同一去除率时改性活性碳纤维的速度更快,并且平衡吸附容量也更大。采用准一级和准二级动力学模型对该吸附过程进行描述,其改性前后均用准二级动力学拟合效果更好,表明活性碳纤维结构的特殊性使其对苯胺的吸附以化学吸附为主。活性碳纤维的等离子体改性提高了其对水溶液中苯胺的吸附速度和容量,增强去除效果降低了苯胺对环境的危害。     

改性活性碳纤维对CO2的吸附性能

为了进一步提高活性碳纤维的CO₂吸附量和抗水性能,采用浸渍法将活性碳纤维进行改性处理,得到一系列改性样品,并对其进行了SEM和FTIR表征。研究了活性碳纤维种类、浸渍试剂（NaOH溶液、ZnCl₂溶液及离子液体）等对吸附剂孔结构、CO₂吸附量、循环使用性和抗水性能的影响,并探讨了CO₂在改性活性碳纤维内的动力学吸附扩散行为。研究结果表明：改性活性碳纤维的CO₂吸附性能和抗水性能均显著改善,其中CO₂最高吸附量达24.4%（0.1MPa和25℃）,吸湿率减小到1.33%,且具有良好的吸附/脱附循环使用性。均相扩散模型（HSDM）描述了实时吸附数据,此模型能够较好地反映CO₂在样品内的扩散行为,改性活性碳纤维仍能保持良好的扩散速率,扩散系数D_s值数量级为10^-5m²/s,与空白活性碳纤维相当。     

Behavior of phenol adsorption on thermal modified activated carbon

Adsorption process is acknowledged as an effective option for phenolic wastewater treatment. In this work, the activated carbon(AC) samples after thermal modification were prepared by using muffle furnace. The phenol adsorption kinetics and equilibrium measurements were carried out under static conditions at temperature ranging from 25 to 55 °C. The test results show that the thermal modification can enhance phenol adsorption on AC samples. The porous structure and surface chemistry analyses indicate that the decay in pore morphology and decrease of total oxygen-containing functional groups are found for the thermal modified AC samples. Thus, it can be further inferred that the decrease of total oxygen-containing functional groups on the modified AC samples is the main reason for the enhanced phenol adsorption capacity. For both the raw sample and the optimum modified AC sample at 900 °C, the pseudo-second order kinetics and Langmuir models are found to fit the experimental data very well. The maximum phenol adsorption capacity of the optimum modified AC sample can reach144.93 mg·g-1which is higher than that of the raw sample, i.e. 119.53 mg·g-1. Adsorption thermodynamics analysis confirms that the phenol adsorption on the optimum modified AC sample is an exothermic process and mainly via physical adsorption.     

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.