共查询到19条相似文献,搜索用时 62 毫秒
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《应用化工》2022,(9)
采用硝酸镧对文冠果活性炭进行改性,利用扫描电镜分析、红外光谱分析、X射线衍射分析等手段对改性前后的活性炭进行表征,考察了Hg(2+)初始浓度、吸附温度、时间对吸附的影响,并研究了吸附过程的吸附等温线、热力学性质和动力学特性。研究表明,当50 mL Hg(2+)初始浓度、吸附温度、时间对吸附的影响,并研究了吸附过程的吸附等温线、热力学性质和动力学特性。研究表明,当50 mL Hg(2+)溶液初始浓度为250 mg/L,吸附时间为150 min,温度为35℃,改性文冠果活性炭添加量为1.0 g/L时,吸附量最大可达78.9 mg/g。硝酸镧改性文冠果活性炭吸附Hg(2+)溶液初始浓度为250 mg/L,吸附时间为150 min,温度为35℃,改性文冠果活性炭添加量为1.0 g/L时,吸附量最大可达78.9 mg/g。硝酸镧改性文冠果活性炭吸附Hg(2+)符合二级动力学方程及Freundlich等温线模型,吉布斯自由能ΔG(2+)符合二级动力学方程及Freundlich等温线模型,吉布斯自由能ΔGo<0、焓变ΔHo<0、焓变ΔHo<0、熵变ΔSo<0、熵变ΔSo<0,表明该吸附是一个自发的放热过程。 相似文献
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活性炭的硝酸表面改性及其吸附性能 总被引:2,自引:0,他引:2
用硝酸对粒状活性炭进行了表面改性,考察了硝酸浓度及氧化时间对活性炭表面官能团的影响.采用傅里叶变换红外光谱仪(FT-TR)、Boehm滴定、X射线衍射仪(XRD)、物理吸附以及颗粒强度分析仪等对氧化前后样品进行了表征分析.以改性活性炭为载体,浸渍活性组分后制备了浸渍炭催化剂,考察了其对氯化氰防护性能.研究发现,低浓度硝酸氧化改性可增加活性炭表面酸性基团的含量,减少碱性基团的含量,从而提高活性炭的表面亲水性,而对活性炭的结构没有明显影响;制备的浸渍炭催化剂对氯化氰防护时间明显增长.当硝酸浓度为8%,氧化时间为8 h时防护效果最好. 相似文献
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为评价吸附后活性炭再生效果,对吸附重金属离子活性炭的再生工艺进行了研究。考察了各因素对再生活性炭性能的影响。结果表明:升高再生温度及延长再生时间,活性炭质量损耗率随之上升,活性炭性能恢复率随之增加。增加再生次数,活性炭质量损耗率随之上升,活性炭性能恢复率随之降低。 相似文献
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采用硝酸氧化法对活性炭(AC)进行改性,考察改性前后活性炭的孔面结构与表面性质的变化,并进行双酚A吸附特性的对比。BET分析表明,改性后活性炭(MAC)虽然比表面积减小,但总孔容增大,平均孔径也由改性前的1.87nm增大到2.01nm。FTIR分析表明,MAC的表面引入羧酸等含氧基团,减少了醌基等基团。AC的双酚A的平衡吸附量约为3.72mg/g,且随初始浓度的增大,吸附量变化不大,而MAC对双酚A的平衡吸附量随初始浓度增大而明显增大,当溶液初始浓度为100mg/L时,最大吸附量在5.78mg/g左右。说明硝酸改性活性炭更利于对双酚A的吸附。 相似文献
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采用反应结晶技术制备了改性活性炭材料(Mg-GAC),并采用 SEM、XRD表征手段对改性前后活性炭进行微观分析,进而研究了 GAC 和 Mg-GAC随吸附时间、溶液pH值和温度变化对废水中铜离子的吸附效果影响。结果表明,GAC经改性后,大大增加了其比表面积,增至738.01m2/g。在Mg-GAC 投加量为0.3g,铜离子浓度为40mg/L,温度为25℃,pH为7的条件下反应2 h,其吸附量达到11.66mg/g。另外,铜离子的吸附过程符合 Langmuir 等温模型。 相似文献
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Yu Bian Zhaoyong Bian Junxiao Zhang Aizhong Ding Shaolei Liu Lei Zheng Hui Wang 《中国化学工程学报》2015,23(10):1705-1711
The adsorption of aqueous cadmium ions (Cd(II)) have been investigated for modified activated carbon (AC-T) with oxygen-containing functional groups. The oxygen-containing groups of AC-T play an important role in Cd(II) ion adsorption onto AC-T. The modified activated carbon is characterized by scanning electron microscopy, Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The results of batch experiments indicate that the maximal adsorption could be achieved over the broad pH range of 4.5 to 6.5. Adsorption isotherms and kinetic study suggest that the sorption of Cd(II) onto AC-T produces monolayer coverage and that adsorption is controlled by chemical adsorption. And the adsorbent has a good reusability. According to the FT-IR and XPS analyses, electrostatic attraction and cation exchange between Cd(II) and oxygen-containing functional groups on AC-T are dominant mechanisms for Cd(II) adsorption. 相似文献
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《应用化工》2022,(11):2816-2820
利用HNO_3对草鱼鱼鳞浸泡改性制备吸附剂,通过系列吸附实验,考察甲基橙初始浓度、鱼鳞投加量和吸附温度等因素对改性鱼鳞吸附水中的甲基橙性能的影响,通过FTIR、XRD、吸附等温线和吸附动力学分析吸附机理。结果表明,鱼鳞用1 mol/L HNO_3浸泡3 h所制备的吸附剂对甲基橙染料废水具有很好的吸附性能;在室温(20~25℃)条件下,溶液pH介于4~9,10 g/L改性鱼鳞吸附剂的投加量和初始甲基橙浓度为100 mg/L时,改性鱼鳞吸附剂对甲基橙吸附在反应2 h时效果最佳;通过吸附等温线实验发现,HNO_3改性鱼鳞对甲基橙的吸附符合Freundlich吸附等温式,而动力学实验表明吸附过程符合准二级动力学模型;FTIR和XRD分析表明,HNO_3改性鱼鳞溶解了其中部分羟基磷灰石,对甲基橙的吸附主要是改变其物理结构而提高吸附效果。 相似文献
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Adsorption equilibrium of copper ion and phenol by powdered activated carbon, alginate bead and alginate-activated carbon bead 总被引:1,自引:0,他引:1
Tae Young Kim Hyung Ju Jin Seung Sik Park Seung Jai Kim Sung Young Cho 《Journal of Industrial and Engineering Chemistry》2008,14(6):714-719
The adsorption equilibrium characteristics for single and binary components of copper ion and phenol onto powdered activated carbon, alginate bead and alginate-activated carbon (AAC) bead were studied. Adsorption equilibrium data of phenol and copper ion onto the adsorbents could be represented by Langmuir equation. The adsorption capacity of Cu2+ onto different adsorbents was in the following order: alginate bead > AAC bead > powdered activated carbon (PAC). On the other hand, that of phenol was: PAC > AAC bead > alginate bead. Multi-component equilibrium data were correlated by three different models. Among them the ideal adsorbed solution theory (IAST) gave the best fit to our data. And the adsorption amount of Cu2+ onto AAC bead was greater than that of phenol in the binary components. 相似文献
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S. Parkash 《Carbon》1974,12(1):37-43
Four activated carbons, one of them commercially available Darco active carbon and the remaining three from a series of coconut charcoals steam activated to varying degrees, are used to study the adsorption of weak and non-electrolytes. Introduction of —CI into the CH3COOH molecule increases adsorption onto activated carbon while —OH and —NH2 have the opposite effect. Substitution in the benzene ring shows that adsorption from aqueous solutions is in the order —NH2, >—OH, >CO2, >(—OH + —COOH). Effect of polarity of solvent on adsorption capacities is studied in H2O, CHCl3 and C6H6. Substitution of —Cl into the CH3COOH molecule invariably increases the adsorption irrespective of the polarity of the solvent. On introducing a specific group in the benzene ring the adsorption is in the order: aniline ? phenol > benzoic acid > salicylic acid in H2O medium but in CHCl3 and C6H6 media aniline ? phenol > salicylic acid > benzoic acid. However, on comparing the results of individual adsorbates in three media, generally the magnitude of adsorption is H2O > C6H6 ? CHCl3. Adsorption of lower aliphatic acids (formic to caproic) from aqueous solutions increases regularly as one ascends the homologous series—a behaviour known as Traube's rule; however, of all the surface area available for N2 adsorption, only a fraction of it is available for adsorption of the aliphatic acids. 相似文献
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以硝酸改性活性炭为原材料,制备电吸附电极,并研究其对8种常见金属盐离子的吸附特性;分别采用扫描电镜、比表面积及孔径分析仪、红外光谱仪和电化学工作站等对改性前后材料的性能进行表征和分析。结果表明:改性后的活性炭相比于改性前拥有更好的孔隙结构,含氧官能团增多,制备出的电极电化学性能更好;在除盐实验中,制备的电极对价态越高的离子去除速率越快但去除率越低;对于同价态离子,水合离子半径越小时去除速率越快且去除率越高;离子从溶液到电极表面再到活性材料孔道内部的过程,主要为物理吸附过程,也存在较微弱的化学吸附。 相似文献
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Sheng H. Lin 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1993,57(4):387-391
The purpose of this laboratory study is to investigate the effectiveness of powered activated carbon (PAC) on the removal of chemical oxygen demand (COD) and color of disperse dye and the effect of PAC particle size on the treatment efficiency. The adsorption isotherm parameters for the Langmuir, Freundlich and BET model are determined using the adsorption data. It has been found that the multilayer BET isotherm yields significantly better fit to the observed data than the monolayer ones. A simplified mass transfer model is proposed in the present work also for estimating the external mass transfer coefficient using the initial adsorption data at low PAC dosage. 相似文献
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活性碳纤维对硝基酚的吸附行为和应用研究 总被引:8,自引:0,他引:8
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。 相似文献
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Adsorption of chromium by activated carbon from aqueous solution 总被引:3,自引:0,他引:3
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. 相似文献