Adsorption characteristics of carbon tetrachloride from aqueous solution onto polyacrylonitrile-based activated carbon fiber

The isotherm, mechanism and kinetics of carbon tetrachloride (CT) adsorption by polyacrylonitrile-based activated carbon fiber (PAN-ACF) were investigated in batch reactors and a continuous flow reactor, and the regeneration of PAN-ACF was also studied. Freundlich and Dubinin-Radushkevich (D-R) adsorption equations can well describe the adsorption isotherm. CT is mainly adsorbed on the exterior surface of PAN-ACF with low boundary layer effect and rate-controlling step of intra-particle diffusion. The adsorption dynamics in the batch reactor well fits with the pseudo-first-order model, and the breakthrough curves in the continuous flow reactor can be well described by the Yoon-Nelson model. The ACF can be recycled through thermal regeneration, whereas the adsorption capacity decreases from 7.87 to 4.98 mg/g after the fourth regeneration. 78%–94% of CT can be removed from the wastewater of a fluorine chemical plant on a pilot scale, which confirms the efficacy of ACF under industrial conditions. The results indicate that PAN-ACF is applicable to CT removal from wastewater.     

改性累托石吸附处理亚甲基蓝机理研究

改性累托石用于亚甲基蓝染料废水处理更具普适性.改性累托石能较好的用Langmuir公式和Freundlich公式来描述,改性累托石的Langmuir表达为Ce/qe=0.020 96+0.015 51Ce,Freundlich表达式为lgqe=1.695 52+0.057 03 lgCe.分别用lagergren准一级、准二级吸附速率模型、Bangham模型和Elovich模型对改性累托石吸附亚甲蓝的吸附动力学过程进行拟合.除Lagergren准一级动力学方程外,其他三种动力学方程的拟合线性系数都较高,说明这三种动力学模式都能很好的描述本试验吸附过程动力学规律.     

污泥半焦对亚甲基蓝的吸附

利用污泥半焦的吸附性能对亚甲基蓝溶液进行吸附实验,并得出最佳条件.结果表明, 反应温度为40 ℃, 溶液pH 值为11, 半焦投加量为2 g/L, 吸附时间为30 min,亚甲基蓝的质量浓度为15 g/L时,污泥半焦对亚甲基蓝的脱色率可高达89.79%,污泥半焦具有良好的吸附效果, 对亚甲基蓝的吸附行为符合Langmuir等温方程.     

Adsorption of K+ from an aqueous phase onto an activated carbon used as an electric double-layer capacitor electrode

The adsorption capacity and absorption rate for electrolyte onto activated carbon are important parameters used to characterize activated carbon electric double-layer capacitor electrodes. In this paper the pore structure of typical commercial activated carbons, and various Mn-doped activated carbons prepared on a laboratory scale, are described. The pore structure was characterized by N2 adsorption/desorption isotherms. Isotherms for K+ adsorption onto these activated carbons from the aqueous phase were also obtained. The experimental, equilibrium K+ adsorption data were fitted to the Langmuir, Freundlich or Temkin equations. Adsorption of K+ onto the activated carbons was measured and plotted as a function of time. The adsorption kinetic data were modeled by either pseudo-first or pseudo-second order equations. The Elvoich equation, a liquid film diffusion and an intra-particle diffusion model were used to fit the kinetic data. The results indicate that the adsorption of K+ onto activated carbon is influenced by many factors including pore size distribution, specific surface area and the surface chemistry of the activated carbons. The Temkin equation best describes the equilibrium adsorption data. The pseudo-second order model exactly describes the whole adsorption process, which is controlled by both liquid film and intra-particle diffusion.     

金属盐类改性累托石的制备及吸附性能

为得到吸附性能更优的废水处理材料,在最适宜改性条件下采用氯化铁溶液、碳酸锂草酸溶液和焦磷酸钠溶液分别制得铁盐改性累托石、锂盐改性累托石和钠盐改性累托石;取原累托石和三种盐类改性累托石为吸附剂,考察原累托石与改性累托石对亚甲基蓝、甲基紫、孔雀石绿和中性红4种染料废水的吸附效果,其中累托石用量0.1 g,染料废水用量200 mL质量浓度为100 mg/L.结果表明:3种盐类改性累托石对4种染料废水的去除率和平衡吸附量明显优于原累托石,3种盐类改性累托石中铁盐改性累托石和锂盐改性累托石吸附效果优于钠盐改性累托石.对原累托石及3种盐类改性累托石进行扫描电镜分析,发现改性后累托石层间距明显增大,且改性过程并未改变累托石的片层结构. 由此可见,盐类改性累托石具有优良的吸附性能,其中铁盐改性累托石和锂盐改性累托石的吸附性能更优.     

改性活性炭对水溶液中氟离子的吸附性能

选用氧化镁改性活性炭（MgO—AC）为新型吸附剂,用于去除水溶液中的氟离子．系统地研究了反应时间、吸附剂最佳投加量、pH、温度等因素对吸附剂除氟性能的影响情况．反应系统达到吸附平衡的时间为180min．吸附剂最佳投加量为2．8g／L．pH值是影响吸附过程的重要因素之一,本研究最佳反应pH范围为6．0—8．0．吸附等温线研究发现MgO—AC除氟剂吸附等温线方程均符合Langmuir吸附等温线模型,且吸附量随着温度的升高而升高．吸附动力学研究发现动力学数据较好的的符合伪二级动力学模型．本研究对MgO—AC除氟的机理进行了初步探讨．廉价以及较高的吸附性能等优点表明MgO—AC是一种有实际应用潜力除氟材料．     

羟基磷灰石对水溶液中锌离子的吸附动力学

研究了羟基磷灰石对水溶液中锌离子的吸附动力学.研究结果表明羟基磷灰石对水溶液中锌离子的吸附符合Langmiur等温吸附:ρR/q=0.15297ρR+0.12247;该吸附反应符合二级反应动力学方程:1/ρR=0.01084t+0.49689;反应速率k1和温度T之间的关系符合阿仑尼乌斯(Arrhenius)公式:lnk1=-0.89525×1/T+0.15541,吸附的活化能为Ea=7.444J/mol.     

Comparison of Conventional and Microwave-assisted Synthesis and Characteristics of Aluminum-pillared Rectorite

The synthesis and characterization of aluminum-pillared rectorite were studied. The synthesis was conducted with both conventional heating and microwave irradiation. Microwave irradiation was found to enhanee the intercalation and ion-exchange during synthesis, and to be able to produce the rectorite with a larger d001 aad a better uniformity. The specific surface area is 180 m^2 / g and basal spacing is 3.2 nm.The texture change and thermal and hydrothermal stability of cross- linked rectorite were examined using XRD, FTIR, nitrogen-adsorption and TGA. The experimental results show that the aluminum-pillared rectorite, after calcined at 800℃ for 3 hours, can keep the basal aluminum-silicate texture and would not disperse in water at room or an elevated temperature. The alumimum-pillared rectorite shows a high specific surface area, good thermal and hydrothermal stability, and is promising in applications as catalyst carriers and adsorbents for waste treatment.     

Adsorption behavior of molybdenum onto D314 ion exchange resin

The adsorption behavior of molybdenum onto D314 was studied with the static adsorption method. The adsorption process was analyzed from thermodynamic and kinetic aspects. The experimental results show that the equilibrium adsorption data conform satisfactorily to the Langmuir equation. In the adsorption process of D314 for molybdenum, the enthalpy change ΔH is positive when temperature is in the range of 298-338 K, which indicates that the adsorption is an endothermic process, and the elevated temperature benefits to the adsorption. Kinetic analysis shows that the adsorption rate is controlled by intraparticle diffusion and chemical diffusion at the same time. The adsorption mechanism of molybdenum onto D314 was discussed based on IR spectra.     

天然锰矿对水体中磷的去除研究

研究了天然锰矿对水体中磷的去除效果,考察了温度、光照、锰矿用量、溶液pH及共存离子对除磷效果的影响。结果表明,pH对磷的吸附影响很大。离子影响中,Ca2+、Mg2+、CO32-、HCO3-、SiO32-和SO24-的影响不大,而AsO43-和AsO3-却能明显抑制锰矿对磷的吸附。Freundlich等温吸附模型(r2=0.984 4)能很好的描述磷的吸附。动力学数据符合二级动力学模型(r2=0.999 9),最大吸附量为30.40μg/g。FTIR和SEM结果显示磷主要是通过与锰矿表面的羟基发生置换或生成内层络合物而被吸附。天然锰矿,具有较大的比表面积,强选择性,是一种很有前景的去除天然水体中磷的吸附剂。     

改性粉煤灰吸附水中诺氟沙星的热力学研究

利用碱改性粉煤灰吸附脱除水中诺氟沙星,采用平衡法测定了改性粉煤灰的平衡吸附量并用Freundlich模型进行了关联,计算了模型参数以及ΔG、ΔH和ΔS等热力学参数.结果表明,改性粉煤灰的比表面积为改性前的3.24倍;实验数据能较好地服从Freundlich模型;改性粉煤灰对水中诺氟沙星的吸附为自发、放热的熵减过程.     

超细粉煤灰基吸附剂吸附次甲基蓝动力学研究

将粉煤灰粉碎、化学处理、复合成型处理后制得一种超细粉煤灰基吸附剂.研究该吸附剂吸附水溶液中次甲基蓝的吸附动力学和吸附机理.通过分光光度法测定在不同吸附时间溶液中的剩余次甲基蓝吸光度值,求出溶液中剩余的次甲级蓝的浓度以及吸附在吸附剂上的次甲级蓝吸附量,根据不同时间的吸附量拟合吸附动力学方程.结果表明,该吸附剂对次甲基蓝的吸附符合二级动力学速率方程,求得平衡吸附量为0.827 4mg/g,求得在两个不同温度下的吸附速率常数分别为:(298K)0.798 g/(mg·min)、(313K)0.963 g/(mg·min),吸附活化能()为9.684 kJ/mol.本实验探索了以粉煤灰为原料制备的超细吸附剂对次甲基蓝废水治理新途径,为粉煤灰的综合利用提供理论依据.     

稀硫酸改性花生壳对亚甲基蓝的吸附性能研究

研究稀硫酸改性花生壳对亚甲基蓝的吸附性能,探讨了吸附时间、初始浓度、pH值、温度等因素对吸附性能的影响,并研究了花生壳的再生和重复使用率.结果显示：改性花生壳对亚甲基蓝的最大吸附率为94.53%,最大吸附量为18.53 mg/g;吸附行为满足Langmuir吸附等温式;花生壳可再生使用.     

磁性类水滑石吸附水中磷的研究

为克服固定床吸附技术床层容易堵塞、不适合处理悬浮物浓度过高污水的限制,以在微米级四氧化三铁粉末表面共沉淀的方法制备一系列磁性Mg-Al,Zn-Al,Ca-Al,Mg-Fe,Zn-Fe和Ca-Fe类水滑石磷吸附剂,研究其对含磷酸盐废水的吸附性能.结果表明,这些磁性类水滑石化合物中二价和三价阳离子的组成对磷酸根吸附性能有显著影响,其中以Mg/Al投料比为2∶1制备的磁性类水滑石吸附剂吸附容量最高,饱和吸附容量达85.5mgP/g,吸附等温线符合Langmuir方程.pH对吸附有一定的影响,在pH5～7范围内吸附效果较好.     

磷化氢在活性炭上的吸附及吸附等温线的预测

为回收工业废气中的PH3并资源化,通过容积法对比了2种活性炭在25℃下对PH3的饱和吸附容量,研究了不同温度下PH3气体在AC1上的等温吸附行为,利用Boehm滴定法测试了2种活性炭的表面酸性基团。结果表明,含酸性基团较多的AC1更有利于PH3的吸附,在实验条件范围内25℃、40℃、55℃、70℃下PH3在AC1上的饱和吸附容量分别为4.247 mg/g,2.750 mg/g,2.088 mg/g和1.527 mg/g。由Clausius-Clapeyron方程计算而得的等量吸附热很好地预测了各实验温度下的吸附等温线。PH3气体在AC1上的等量吸附热随吸附量的增大而减小,表明AC1表面能量的不均匀性。在实验条件下,PH3的等量吸附热小于30 kJ/mol,过程为物理吸附,便于PH3气体的解吸。     

化学改性橘子皮对Pb~(2+)的吸附性能

研究了经化学改性的橘子皮吸附剂对Pb2+的吸附性能.考察了溶液pH值、吸附时间及Pb2+初始质量浓度对该吸附剂吸附性能的影响.结果表明,吸附过程可以很好地用准二级动力学方程描述,吸附等温线用Langmuir方程拟合效果优于Freundlich方程.pH4.5,30℃时最大吸附容量为146.4 mg/g.经改性的橘子皮可重复使用5次以上.     

生物质材料荷叶对碱性品红的吸附性能研究

研究了吸附时间、溶液pH值、吸附剂用量、染料初始浓度、盐离子浓度以及温度对荷叶吸附水溶液中碱性品红(BF)的影响.Langmuir,Freund lich,Koble-Corrigan等温吸附模型对吸附平衡数据进行非线性回归分析.结果表明:Kob le-Corrigan等温线方程对平衡实验数据拟合良好.荷叶对碱性品红的吸附行为符合准二级动力学模型,该吸附属于化学吸附.生物质吸附剂荷叶对水溶液中的碱性品红有很好的去除能力.     

改性麦草秸秆对活性艳红的吸附动力学研究

为实现农作物秸秆资源化,解决印染废水难处理问题,将麦草秸秆经过化学改性后制备成一种有效吸附染料的吸附剂,通过静态实验,研究了吸附剂对不同质量浓度、温度和振荡速度下对活性艳红的吸附动力学特性,并考察了在不同pH值、麦草投加量下,改性麦草秸秆对活性艳红吸附效果的影响。分别用伪一级动力学方程、伪二级动力学方程、Elovich方程和颗粒内扩散方程进行拟合。结果表明:改性麦草秸秆对活性艳红的吸附动力学过程可以用伪二级动力学模型进行很好地描述,颗粒内扩散模型表明,颗粒内扩散为主要速率控制步骤。吸附活化能为17.21kJ／mol,说明该吸附过程以物理吸附为主。     

载锆颗粒活性炭吸附去除水溶液中的硫酸根离子

制备负载氧化锆的颗粒活性炭(Zr-GAC),以吸附水溶液中的硫酸根离子.采用扫描电镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)和比表面积测定等方法对Zr-GAC进行表征.结果表明,Zr-GAC具有多孔的表面积,其上具有许多由氧化锆组成的团聚体.XPS分析证实,吸附剂表面存在大量的锆和羟基,氧化锆改性后...     

粉末活性炭吸附水中氯苯的动力学研究

为了解粉末活性炭(PAC)对水中氯苯的吸附性能,研究了4种PAC对水中氯苯的吸附动力学,并对4种PAC的物理特征及孔径分布进行了分析.结果表明:4种PAC均具有较广的孔径分布,其对氯苯的平衡吸附量随比表面积和孔容积的增大而增大.PAC对氯苯吸附速率很快,5 min吸附量可达到平衡时的80%以上,30 min后吸附基本达到平衡.假二级和假三级动力学模型均能较好地描述吸附过程,假二级模型更适合描述2 h以内的吸附过程,假三级模型适合描述吸附时间大于2 h的吸附过程.