活性炭对苯酚的吸附研究

进行了活性炭处理含苯酚废水的应用研究,考察了影响苯酚吸附效果的因素。确定了处理水中苯酚的最佳条件:吸附平衡时间为30 min;最佳pH值为6左右;苯酚初始浓度为10 mg/L;投炭量为20～25 mg/L;苯酚的吸附率高达97.4%;温度对苯酚吸附率的影响不明显。研究了活性炭对苯酚的吸附动力学特性,分别用伪一级动力学方程、伪二级动力学方程、修正伪一级动力学方程和颗粒内扩散模型进行拟合,对于不同浓度的苯酚废水都只有伪二级动力学方程拟合程度比较高,伪二级动力学方程更为真实地反映苯酚在活性炭上的吸附机理。     

Adsorption of lead(II) from aqueous solution by activated carbon prepared from Eichhornia

Activated carbon prepared from Eichhornia was used for the adsorptive removal of Pb(II) from aqueous solution. As the raw material for the preparation of the activated carbon is an aquatic weed, the production of this carbon is expected to be economically feasible. Parameters such as agitation time, metal ion concentration, adsorbent dose and pH were studied. Adsorption equilibrium was reached in 100 min for a solution containing 15 mgdm^?3 and 125 min for solutions containing 20 and 25 mgdm^?3 Pb(II), respectively. Adsorption parameters were determined using both Langmuir and Freundlich isotherm models. The adsorption capacity was 16.61 mgg^?1 at pH 3.0 for particle sizes of 125–180 µm. Pb(II) removal increased as the pH increased from 2 to 4 and remained constant up to pH 10.0. Desorption studies were also carried out with dilute hydrochloric acid to recover both carbon and Pb(II). Quantitative desorption of Pb(II) from carbon indicates that adsorption of metal ion is by ion exchange. © 2002 Society of Chemical Industry     

活性炭纤维吸附废水中酚的研究

通过静态和动态试验对活性炭纤维吸附废水中的酚进行了研究,测定了吸附等温线,考察了活性炭纤维的用量、苯酚浓度,以及过柱流速对吸附的影响.结果表明,活性炭纤维对苯酚的动态吸附容量为256 mg/g随着活性炭纤维用量的增加,处理水稳定时间延长;苯酚浓度越高,穿透时间越短;过柱流速越大,穿透时间越短;吸附饱和后的活性炭纤维再生后,吸附容量几乎不变.     

Adsorption of thiram from aqueous solution on activated carbon and sepiolite

Adsorption of thiram on activated carbon and acid-heat treated sepiolite from aqueous solution at 10° C, 20° C, 30° C and 40° C has been studied. The adsorption isotherms may be classified as L type of the Giles classification which suggests that there is no strong competition from the solvent for adsorption sites. The experimental data points have been fitted to the Langmuir equation in order to calculate the adsorption capacities of the solids as well as their surface areas available to the thiram molecules. The removal efficiency (P) has been calculated for both adsorbents resulting that activated carbon is more effective (P = 98–100%) in removing thiram from aqueous solution than acid-heat treated sepiolite (P = 14–52%).     

苯酚在活性炭纤维上的吸附平衡及动力学研究

利用活性炭纤维（ACF）吸附法处理含苯酚模拟废水,通过间歇静态吸附,测定了室温下苯酚初始浓度及吸附剂质量对吸附性能的影响。结果表明,Freundlich模型能较好地描述该吸附等温过程,苯酚在ACF表面发生多分子层物理吸附;苯酚由溶液主体传递到ACF表面为传质控制步骤。利用超声碱洗方式再生饱和吸附剂,再生后ACF对苯酚吸附容量保持较好。     

Adsorption of trivalent chromium from aqueous solutions onto activated carbon

The adsorption of chromium (III) onto activated carbon was investigated as a possible alternative method for its removal from aqueous solutions. The adsorption data were obtained in a batch adsorber and fitted the Langmuir adsorption isotherm well. The effect of pH on the adsorption isotherm was investigated at pH values of 2, 4, 5 and 6. It was found that at pH values below 2 the Cr(III) was not adsorbed and at pH values above 6.4 the Cr(III) was precipitated as Cr(OH)₃. Maximum adsorption occurred at pH 5. The pH plays a very important role in the adsorption of Cr(III) since Cr(III) can form different complexes in aqueous solutions. The adsorption capacity was increased by about 20% as the temperature was raised from 25 to 40°C. It was concluded that Cr(III) is adsorbed to an appreciable extent on activated carbon and that the adsorption is highly dependent upon pH.     

花生壳制活性炭及其脱六价铬研究

本文研究了用花生壳制备活性炭和用此活性炭去除水溶液中的Cr（Ⅵ）。采用化学活化法,即用H2SO4、H3PO4、ZnCl2、KOH活化花生壳中的炭。同时研究了这些活化剂的浓度和用量、热解时间和温度对活性炭性能的影响。采用亚甲基蓝吸附实验评价活性炭的性能。结果表明H3PO4和ZnCl2是良好的活化剂,KOH和H2SO4效果较差。溶液的pH值对活性炭吸附Cr（Ⅵ）的能力有很大影响。活性炭的吸附能力随着pH值的降低而升高,同时在不同的pH值下,炭的吸附速率也不同。pH值越低,Cr（Ⅵ）被吸附的越快。等温实验结果表明,在pH值等于2时,用H3PO4和ZnCl2活化的活性炭对Cr（Ⅵ）的吸附能力分别达到125．0和83．3mg·g^-1。花生壳活性炭吸附Cr（Ⅵ）的机理比较复杂,与溶液的pH值有关。在pH值等于2时,等温吸附可以用Langmuir模型模拟;在pH值等于2～7时,可以用Freundlich模型模拟。     

水中Ni~(2+)在粒状沸石/活性炭复合材料上的吸附研究

采用廉价的煤矸石为主要原料,添加一定量的沥青粉制备了沸石NaA/活性炭粒状复合材料,并以此作为吸附剂,研究了水溶液中Ni~(2+)在该复合材料中的吸附行为,考察溶液的初始浓度、吸附时间和pH对吸附的影响.结果表明溶液较高的pH值有利于Ni~(2+)在吸附剂上的吸附;随Ni~(2+)初始浓度的增大复合材料的吸附量增大,而Ni~(2+)的去除率随之减小;Ni~(2+)在复合材料上的吸附接近Langmuir-Freundlich等温吸附模型,反映了吸附表面的多相性及两类吸附中心在复合材料上的共存性;吸附速率遵循准二级吸附动力学模型.     

油茶果壳活性炭的制备及其对苯酚的吸附

以油茶果壳为原料,60%的磷酸溶液为活化剂制备了油茶果壳活性炭,探讨了料液比、活化温度与时间对油茶果壳活性炭吸附苯酚性能的影响。结果表明,在活化温度为600℃,活化时间为90 min,料液比(g∶g)为1∶3时,制备的油茶果壳活性炭对苯酚的吸附效果最好。油茶果壳活性炭对苯酚吸附的最佳条件为:在30℃,0.1 g油茶果壳活性炭对100 mL的500 mg/L苯酚吸附5 h后,吸附量达到了218.0 mg/g。     

活性炭纤维吸附邻硝基苯胺水溶液的研究

采用活性炭纤维(ACF)处理邻硝基苯胺模拟废水,通过静态和动态吸附实验,研究了pH、盐含量、吸附时间对吸附效果的影响,测定了吸附等温线和动态穿透曲线,并进行了ACF再生实验。结果表明,在实验条件下,ACF对邻硝基苯胺的吸附速率很快,5 min去除率达96%,在pH4.4~10.4条件下吸附效果较好,盐的含量对吸附效果影响较小,吸附等温线能用Langmuir和Freundlich方程较好地拟合。溶液流速增大,穿透时间提前,吸附饱和的ACF用无水乙醇再生,重复5次,邻硝基苯胺的回收率均在95%以上,ACF的吸附效率无明显变化。     

Intraparticle diffusion of cadmium and zinc ions during adsorption from aqueous solution on activated carbon

The adsorption isotherms of cadmium(II) and zinc(II) onto activated carbons were obtained in a batch adsorber. The concentration decay data were obtained in a rotating basket adsorber and were interpreted by a mathematical model, which takes into account the adsorption rate, external mass transport and intraparticle diffusion. The results showed that the overall rate of adsorption of Cd(II) and Zn(II) was mainly controlled by the intraparticle diffusion which was solely due to pore volume diffusion. The contribution of the external mass transport resistance was negligible. The effective pore volume diffusivities of Cd(II) and Zn(II) were predicted reasonably well using the ionic diffusivity of the metal and the void fraction and tortuosity of activated carbon. Copyright © 2005 Society of Chemical Industry     

褐煤活性炭吸附苯酚的研究

The feasibility and adsorption effect of lignite activated carbon for phenol removal from aqueous solutions were evaluated and investigated. A series of tests were performed to look into the influence of various experimental parameters such as contact time, initial phenol concentration, temperature, and pH value on the adsorption of phenol by lignite activated carbon. The experimental data were fitted well with the pseudo-second-order kinetic model. The adsorption is an endothermic process and conforms to Freundlich thermodynamic model. The results indicate that the lignite activated carbon is suitable to be used as an adsorbent material for adsorption of phenol from aqueous solutions.     

Adsorption of fulvic acids from aqueous solutions by carbon nanotubes

Carbon nanotubes (CNTs) were used as adsorbent to remove fulvic acids (FA) from aqueous solutions. The adsorption capacity of CNTs for FA can reach 24 mg g^?1 at 5 °C and equilibrium concentration of 18 mg dm^?3. The kinetic and thermodynamic parameters, such as rate of adsorption, standard free energy changes (ΔG⁰), standard enthalpy change (ΔH⁰) and standard entropy change (ΔS⁰), have been obtained. Acidic conditions (pH = 2–5) favor FA removal. An increase in the ionic strength or the addition of divalent cations increase the adsorption of FA dramatically (FA = 60 mg dm^?3). An increase in the maximum adsorbed amount of FA was observed when treating FA in synthetic seawater. Desorption studies reveal that FA can be easily and quickly removed from CNTs by altering the pH values of the solution. Good adsorption capacity and quick desorption indicate that CNTs are a promising adsorbent to remove FA from aqueous solutions. Copyright © 2007 Society of Chemical Industry     

Adsorption of cadmium and zinc from aqueous solution on natural and activated bentonite

The adsorption of cadmium and zinc ions on natural bentonite heat-treated at 110°C or at 200°C and on bentonite acid-treated with H₂SO₄ (concentrations: 0·5 mol dm^?3 and 2·5 mol dm^?3), from aqueous solution at 30°C has been studied. The adsorption isotherms corresponding to cadmium and zinc may be classified respectively as H and L types of the Giles classification which suggests the samples have respectively a high and a medium affinity for cadmium and zinc ions. The experimental data points have been fitted to the Langmuir equation in order to calcualte the adsorption capacities (X_m) and the apparent equilibrium constants (K_a) of the samples; X_m and K_a values range respectively for 4·11 mg g^?1 and 1·90 dm³ g^?1 for the sample acid-treated with 2·5 mol dm^?3 H₂SO₄ [(B)-A(2·5)] up to 16·50 mg g^?1 and 30·67 dm³ g^?1 for the natural sample heat-treated at 200°C [B-N-200], for the adsorption process of cadmium, and from 2·39 mg g^?1 and 0·07 dm³ g^?1, also for B-A(2·5), up to 4·54 mg g^?1 and 0·45 dm³ g^?1 [B-N-200], for the adsorption process of zinc. X_m and K_a values for the heat-treated natural samples were higher than those corresponding to the acid-treated ones. The removal efficiency (R) has also been calculated for every sample; R values ranging respectively from 65·9% and 8·2% [B-A(2·5)] up to 100% and 19·9% [B-N-200], for adsorption of cadmium and zinc.     

中高温环境下VOCs在活性炭上的吸附性能研究

选用3种商用活性炭及其分别经HCl溶液和KOH溶液浸渍改性的商用活性炭,研究中高温烟气环境下,反应空速、吸附温度对挥发性有机物（VOCs）吸附性能的影响,以及VOCs种类、吸附剂特性等与VOCs吸脱附效果的关系。研究发现：空速对吸附穿透时间影响较大,但对饱和吸附量影响不显著。吸附温度与VOCs浓度对饱和吸附量存在较大影响,150℃时甲苯的饱和吸附量仅能达到90℃时的40％。高沸点吸附质更易被吸附,更难被脱附。     

活性炭吸附对二甲苯氧化尾气研究

对纯组分（乙酸甲酯、苯）在不同活性炭上的吸附行为进行了研究,获得了纯组分吸附平衡关系与动力学性质,采用动态吸附法对纯组分、含乙酸甲酯、苯等混和气体的吸附情况进行测定。实验表明,纯组分的吸附遵守Lang-muir规律。多组分吸附的情况下,由于吸附质极性的差别,使得活性炭对醋酸甲酯的吸附能力比苯强。活性炭中孔含量的多少决定醋酸甲酯和苯相互置换程度,中孔含量多的活性炭更容易使醋酸甲酯置换已被吸附的苯。     

微波辐照下载乙醇活性炭的解吸研究

用颗粒活性炭吸附水中低浓度的乙醇,饱和后在氮气氛围中用微波辐照解吸,以实现乙醇的回收和活性炭的再生。研究了吸附过程及解吸过程的影响因素及规律,探索了将微波作为载乙醇活性炭解吸热源的可行性,并进行了工艺条件优化。研究测定了常温下颗粒活性炭对水中低浓度乙醇的吸附等温线,发现可用Freundlich吸附模型较好地拟合。设计了载乙醇活性炭微波解吸的试验流程,对反应器的设计、微波场中的温度测量进行了探讨。     

活性碳纤维对硝基酚的吸附行为和应用研究

研究了粘胶基活性碳纤维(ACF)在水溶液中对硝基酚的吸附行为,包括ACF对硝基酚的吸附等温线、吸附容量、再生方法、吸附和再生速率、对硝基酚的吸附选择性等。结果表明:ACF对硝基酚的吸附容量达到664mg g,该吸附是一个可逆过程,吸附和解吸速率快;采用质量分数10%的NaOH作再生剂,可以恢复吸附能力,重复进行吸附-再生过程,ACF的吸附容量不变,对硝基酚的回收率均>90%。对进水硝基酚质量浓度为9790mg L的废水,吸附处理后出水浓度达到一级排放标准,同时可以回收硝基酚。     

氢在YK-1活性炭上的吸附平衡

运用容积法在温度区间113—293 K、压力范围0—12.5 MPa测定氢在椰壳活性炭YK-1上的吸附等温线,由等量吸附线标绘和低覆盖率区域等温线的亨利定律标绘确定等量吸附热和极限吸附热,引入格子理论Ono-Kondo方程对吸附等温线进行模型分析。结果表明,氢在YK-1活性炭上等量吸附热随吸附量的变化平缓,等量吸附热的平均值和极限值分别为4.64 kJ/mol和5.37 kJ/mol;基于Ono-Kondo模型的方程能较好地预测吸附等温线,氢在吸附空间的最大吸附容量随温度变化,其值比液氢在相同吸附空间的吸附容量小。须改善材料结构和降低储存系统温度才能提高活性炭的储氢性能。     

Adsorption of chromium by activated carbon from aqueous solution

Adsorption isotherms of Cr(III) and Cr(VI) ions on two samples of activated carbon fibres and two samples of granulated activated carbons from aqueous solutions in the concentration range 20–1000 mg/l have been studied. The adsorption isotherms have been determined after modifying the activated carbon surfaces by oxidation with nitric acid, ammonium persulphate, hydrogen peroxide and oxygen gas at 350°C and after degassing at different temperatures. The adsorption of Cr(III) ions increases on oxidation and decreases on degassing. On the other hand, the adsorption of Cr(VI) ions decreases on oxidation and increases on degassing. The increase of Cr(III) and the decrease of Cr(VI) on oxidation and the decrease of Cr(III) and the increase of Cr(VI) on degassing have been attributed to the fact that the oxidation of the carbon surface enhances the amount of acidic carbon–oxygen surface groups while degassing eliminates these surface groups. Thus while the presence of acidic surface groups enhances the adsorption of Cr(III) cations, it suppresses the adsorption of Cr(VI) anions.