改性骨炭对土壤中锌离子的吸附性研究

用一系列不同浓度的十二烷基磺酸钠(SDS)、双氧水对骨炭进行改性。研究在不同土壤介质中,骨炭对Zn(Ⅱ)吸附效果的差异性。结果表明,对于河流底泥、菜地、荷花底泥3种不同土壤,SDS改性骨炭吸附率较普通骨炭提高6%,H2O2改性骨炭吸附率较普通骨炭下降2%。骨炭能有效吸附去除土壤中的锌污染,且SDS改性骨炭对锌有较好的吸附效果。     

改性活性炭对模拟柴油中噻吩类硫化物的吸附性能

将粉状活性炭(AC)分别经过浓硝酸、浓硫酸和王水氧化后得到3种改性活性炭NAC、SAC和AAC,测定了改性前后活性炭在30℃和50℃对正辛烷溶液中苯并噻吩(BT)、二苯并噻吩(DBT)和3-甲基噻吩(3-MT)的静态等温吸附数据,并用Langmuir方程对数据进行了处理。结果表明,改性后活性炭对噻吩类硫化物的吸附性能均有所增强,其强弱顺序为AAC>NAC>SAC>AC,在30℃下AAC对正辛烷溶液中BT、DBT和3-MT的最大吸附硫含量分别比AC提高了88.7%、63.4%和95.1%。活性炭对噻吩类硫化物的吸附性能强弱与其在红外谱图中含氧官能团的峰强度大小和Boehm滴定分析中含氧官能团数量多少是一致的。在30℃下,再生4次后的AAC对正辛烷溶液中的BT、DBT和3-MT硫的平衡吸附量仍可达到初始吸附量的71.5%、72.7%和40.7%,再生效果良好。     

通过氧化改性提高载银活性炭的抗菌性能

使用浓HNO3和浓H2O2对活性炭进行常温氧化改性,用FTIR和N2吸附法对活性炭进行表面分析,用AAS、SEM、XRD研究银在活性炭表面的吸附和分布特征,并研究了载银活性炭的抗茵性能.结果表明,活性炭经浓HNO3常温改性后,比表面积提高,而经浓H2O2常温改性后,比表面积略有下降,但都使活性炭表面含氧基团增加.改性后,活性炭表面增加的含氧基团为[Ag(NH3)2] 的还原吸附提供更多的活性点,使银的吸附量增大5倍多,银颗粒更加密集,大小更加均一.研究表明,载银活性炭具有明显的抗茵作用,其中对金黄色葡萄球菌的杀灭效果优于对大肠杆菌的杀灭效果,氧化改性使载银活性炭抗茵作用显著增强,其中硝酸改性现象更加明显.     

活性炭的表面处理对二苯并噻吩催化氧化脱除的影响

将一种木质活性炭经过三种表面处理,即高锰酸钾稀硫酸溶液液相氧化、浓硝酸液相氧化和350℃低温气相氧化处理。实验所选活性炭及相应的表面改性炭使用氮气吸附和Boehm滴定分别进行了结构性质和表面化学表征。研究了所选活性炭和相应的表面改性炭催化过氧化氢氧化脱除二苯并噻吩（DBT）。实验结果表明,活性炭表面化学对二苯并噻吩的氧化脱除影响很大;炭表面化学对DBT吸附脱除的影响不同于对DBT氧化脱除的影响,表面酸性越强越有利于DBT的吸附;表面羰基能加速过氧化氢产生自由基,表面羰基量的增加明显有利于DBT的氧化脱除。活性炭经过热处理后,在二苯并噻吩的氧化脱除中催化活性明显增加,正辛烷溶液中硫的体积质量从0.556g·L-1降到0.009g·L-1。     

改性纤维素的制备及分光光度法对Cu~(2+)吸附研究

针对日益严重的铜离子污染问题,以化学浆纤维素为原料,通过氨基酸接枝修饰2,2,6,6-四甲基哌啶氧自由基(TEMPO)氧化体系氧化的纤维素,制备出一种新型吸附剂,并采用灵敏简便的分光光度法研究改性对铜离子的吸附效果。结果表明,氨基酸修饰纤维素(AMC)与TEMPO氧化纤维素(TOC)相比,对铜离子的吸附效果有不同程度的提升,其中组氨酸改性的吸附效果最好,低浓度时吸附率可以高达97%。随着浓度增大,吸附率下降,但是吸附量增大,当吸附200 mg/L的Cu2+溶液时,吸附量可达47 mg/g。此外,研究了不同条件下AMC对Cu2+的吸附情况,包括AMC投加量、初始浓度、pH值等。结果表明,吸附过程的吸附模型符合Langmuir等温模型,吸附动力学可以用准二级吸附动力学方程拟合。     

硫化钠改性活性炭对Pb(Ⅱ)的吸附性能研究

采用质量分数为3%的Na_2S溶液对活性炭浸渍,在600℃以N_2作为保护气对其进行高温处理,研究Na_2S改性活性炭(SAC)吸附Pb(Ⅱ)的动力学和热力学机理,并对吸附Pb(Ⅱ)前后的改性活性炭进行了表征和分析。结果表明,与改性前活性炭相比,SAC的比表面积和总孔容减小,S元素含量显著提高。SAC对Pb(Ⅱ)的吸附效果显著提高,在Pb(Ⅱ)初始浓度为300mg/L时,SAC对Pb(Ⅱ)最大吸附量为122.56mg/g,并且在吸附过程的前80min内可达到总吸附量的95%以上。SAC对Pb(Ⅱ)的吸附过程可用Langmuir模型描述,动力学特性符合拟二级动力学模型。SAC对Pb(Ⅱ)的吸附的热力学参数ΔG在-80~-20k J/mol之间,ΔH0,ΔS0,表明吸附是自发进行的物理吸附与化学吸附共同作用的放热过程。对吸附前后改性活性炭的傅里叶变换红外谱图分析表明,经过Na_2S改性后,活性炭表面引入了砜基,并且砜基强化了改性活性炭对Pb(Ⅱ)的吸附性能。     

微波改性活性炭用于烟气脱硫脱硝的实验研究

在用浓硝酸、氢氧化钾化学改性活性炭的基础上,使用专门设计的微波发生器对活性炭进行热处理,制备了一种高效的活性炭吸附剂用于烟气脱硫脱硝。改性活性炭对模拟烟气的吸附实验表明,活性炭经微波改性后的脱硫吸附量明显提高,氢氧化钾浸泡加微波改性的脱硫效果最好,浓硝酸浸泡加微波改性的活性炭对氮氧化物也有比较好的吸附效果,NO的吸附容量可达到36.8×10-3。扫描电镜(SEM)显示,微波改性后的活性炭微孔充分,有利于污染物的脱除。此外,还对各种改性方法提高活性炭脱硫脱硝性能的机理进行了分析。     

石油焦系活性炭的吸附脱硫

选取独山子石油焦为原料，以物理活化法制得比表面积达500m2/g～900m2/g的活性炭，进行吸附脱硫研究。采用酸氧化法对活性炭孔结构和微观孔径分布进行改性。酸氧化使活性炭表面酸性官能团含量明显增加，增加量约为原来的5倍。活性炭吸附脱硫性能随表面酸性官能团含量的增加而增大。理想的酸化条件是浓硝酸120℃氧化40min。通过静态吸附实验，活性炭吸附脱硫的最佳条件是，温度25℃，压力1.0MPa，静态吸附6h。最佳条件下吸附脱硫可使模型化合物硫的质量分数从137.9×10－6降至3.1×10－6。从活性炭孔径匹配考察可知，平均孔直径在0.8nm～2.1nm的活性炭对模型化合物硫的质量分数降低具有明显效果。     

活性炭的改性及对Pb2+的动力学吸附研究

论文以活性炭为主体吸附剂，进行氯化铁改性，制备出氯化铁改性活性炭吸附剂，并通过FT-IR、SEM、比表面积和孔体积进行表征。实验进一步探究改性活性炭对Pb²⁺的吸附能力，结果表明，当吸附时间为300 min,吸附剂投加量为0.4 g, pH为6时，吸附效果最佳。在此吸附条件下，改性活性炭对Pb²⁺的去除率达到91.2%。对改性活性炭吸附Pb²⁺进行动力学吸附研究，结果表明二级速率方程能够更好地描述其动力学吸附过程，吸附的机理可归结为氯化铁改性导致活性炭孔道结构中酸性官能团增加，使得金属阳离子与官能团上的H之间产生离子交换作用，有利于吸附的进行，这一实验结果为后期循环吸附研究提供了新依据。     

改性活性炭热反应安全性研究

针对活性炭吸附VOCs过程的安全性问题进行了研究,采用咪唑-脯氨酸离子液体对活性炭进行改性,优化吸附性能。以典型的甲苯气体为例,讨论了改性前后活性炭结构的变化对甲苯吸附性能的影响,并探索了改性前后活性炭的热反应安全性。研究结果表明:咪唑-脯氨酸改性活性炭表面的孔隙数量增多、孔径变大、含氧官能团增加、比表面积和体积增大。改性活性炭对甲苯的吸附量78 mg·g~(-1)是改性前活性炭吸附量36.03 mg·g~(-1)的2.17倍,吸附能力明显提升;粒径为51μm和111μm的两种改性活性炭的自燃温度比未改性活性炭的自燃温度分别提高了22.4℃和19.4℃且到达自燃温度所需时间分别延长了11.17 h和0.75 h。改性活性炭所需活化能为47.32kJ·moL~(-1),热稳定性优于未改性活性炭。     

活性炭的改性研究及对四环素的吸附

研究了改性对活性炭的物理化学性质及其对四环素吸附性能的影响。结果发现,硝酸氧化改性可增加活性炭表面的酸性基团,提高比表面亲水性,降低pHPZC值,同时也改变了活性炭的表面微观形貌。低温、低浓度硝酸氧化改性,增加了活性炭的比表面积,对四环素的吸附以物理吸附为主。高温氧化改性使得比表面积降低,酸性基团增加,且吸附容量与活性炭比表面积、表面总酸度呈一定的线性关系。     

Adsorption of some toxic elements from water samples on modified activated carbon,activated carbon and red soil using neutron activation analysis

A simple and sensitive method for the determination of some metalloids and heavy metals in water samples is presented. The method is based on the preconcentration of the attachment of chelating functionalities with metalloids and toxic metals irreversibly and targeted towards toxic metals adsorbed on modified activated carbon, activated carbon and red soil particles at pH 3.0–9.0±0.2, followed by quantitative determination using instrumental neutron activation analysis (INAA), on the absorbers. Attachment results from attraction that may be physical, chemical, electrical, or a combination of all three. The efficient removal of metalloids and toxic metals, especially arsenic, chromium and mercury is anticipated. The adsorption capacity of the chemically modified activated carbon materials was evaluated for the above mentioned metalloid and toxic metal ions in the presence of iron ions and simulated water samples. Red soil particles containing iron was utilized in the control of oxidation-reduction reaction with metalloids and toxic metals. The preconcentration of the elements of interest on red soil particles, activated carbon and modified activated carbon at different depths, pH and oxidation states was investigated. The results obtained showed good agreement with certified values giving relative errors of less than 10%.     

Potassium bromate modification of the granular activated carbon and its effect on nickel adsorption

Granular Activated Carbon (GAC), a commercial adsorbent for the removal of heavy metals was treated chemically with potassium bromate for it’s surface modification and it’s adsorption capacity was investigated with nickel ions. There was an increase in the adsorption capacity of the modified carbon by 90–95% in comparison to the raw granular activated carbon towards nickel ion adsorption. Potassium Bromate oxidation treatment was employed for a period of about 30 mins initially followed by 60 mins and the oxidized carbons were adsorbed with nickel ions. Metal sorption characteristics of as received and modified activated carbons were measured in batch experiments. Batch adsorption was successfully modeled by Langmuir Isotherm Model which indicates monolayer adsorption. The adsorption isotherms also fit well to the Freundlich Model. Effects of pH of initial solution, time of oxidation and mode of treatment on the adsorption process were studied. Experimental results showed that metal uptake increased with an increase in pH and oxidation time. The samples were characterized by Scanning Electron Microscope (SEM) studies and surface area analyzer.     

邻菲咯啉改性膨润土吸附水中镉离子的研究

通过邻菲咯啉改性膨润土,对水中镉离子进行吸附性能的研究.探讨了投加量、pH值、接触时间、温度等影响因素对改性膨润土吸附镉离子的影响.实验结果表明:在25℃,250 r/min,pH 5.5,NaNO3浓度0.01 mol/L,投加量为5.0 g/L,镉离子质量浓度100 mg/L的条件下,未改性膨润土对水中镉离子的吸附...     

Optimization of lead adsorption from lead-acid battery recycling unit wastewater using H2SO4 modified activated carbon

During the recycling of exhausted lead-acid battery, large amount of wastewater is discharged, which contains the toxic Pb(II) ions in high concentration. In this study, the granular activated carbon after modification with sulfuric acid has been used to remove the Pb(II) ions from this wastewater. Adsorbents were characterized using Fourier Transform Infrared, Scanning Electron Microscope, and X-Ray Diffraction analyzer. Taguchi orthogonal L16 array (4^3) was used for batch adsorption study with four levels of three factors initial pH, adsorbent dose, and contact time. Optimum level of parameters was fourty + nd pH 4.5, time 240 min, and dose 0.05 g/50 mL using signal-to-noise ratio (larger-the-better response). Analysis of variance technique was used to signify the adsorption experiment model. The effect of parameters on uptake capacity of adsorbent has been evaluated. Maximum adsorbent capacity for Pb(II) uptake from wastewater of battery recycling unit was found 8.19 mg/g after modification with sulfuric acid. To further understand the mechanism of adsorption, isotherm and kinetic studies were carried out. Experimental data were well fitted with Langmuir isotherm model and pseudo-second-order kinetic model. The study suggested that H₂SO₄ modified granular activated carbon can be potentially used to remove Pb(II) from lead-acid battery recycle wastewater.     

通过柠檬酸改性提高载银活性炭的抗菌性能

通过负载柠檬酸对活性炭进行改性,用N2吸附法测定活性炭的比表面积,用AAS、SEM、XRD测试技术分析了银在活性炭上的吸附和分布,并研究了载银活性炭的抗菌性能。结果表明,负载柠檬酸使活性炭的比表面积下降约24%,但载银后活性炭的比表面积增大。柠檬酸改性为[Ag(NH3)2] 的还原吸附提供更多的活性点,使银的吸附速率加快,吸附量提高约25%,表面的银颗粒变得非常密集,粒径减小,且颗粒均匀,因此抗菌性能显著增强,其中对金黄色葡萄球菌的杀灭效果明显优于对大肠杆菌的,同时对于高分散Ag/C催化剂的制备及银的回收也具有重要的价值。     

苯基键合高比表面积活性炭的制备及其对挥发性有机化合物的吸附性能研究

以核桃壳为原料,经过碳化、KOH活化, 制备了高比表面积活性炭,通过三甲基氧基苯基硅烷对活性炭表面进行改性,制得苯基键合高比表面积活性炭吸附材料.通过氮气吸附法测定了苯基键合活性炭的比表面积及孔径分布;采用红外光谱、X射线光电子能谱、X射线粉末衍射技术对苯基键合活性炭的有机官能团、表面元素的化学环境及晶体结构进行了表征.将该吸附材料制成采样管,吸附空气中的挥发性有机物,二硫化碳解吸后使用气相色谱进行分析.考察了苯基键合活性炭对乙醇、丙酮、正己烷、乙酸乙酯、四氢呋喃、1,2-二氯乙烷和苯共7种挥发性有机化合物(VOCs)的吸附性能,饱和吸附量在129~216 mg/g之间;在0.05~ 2.50 mg/mL范围内,7种组分的峰高与浓度呈良好的线性关系,检出限在0.92~3.60 mg/m3之间.     

Adsorption of carbonyl sulfide on modified activated carbon under low-oxygen content conditions

Activated carbon sorbents impregnated with KOH, Fe(NO₃)₃, Cu(NO₃)₂, Zn(NO₃)₂ or Co(NO₃)₂ and their applications in catalytic oxidation reaction of COS were investigated. The results showed that the activated carbon modified with 10 % (mass percentage) KOH enhanced the adsorption ability significantly. And it was also found that the oxygen content and temperature were the two most important factors in the COS adsorption. Further investigation on the pore structures of the samples with X-ray photoelectron spectroscopy indicated that an adsorption/oxidation process happened in the KOH modified activated carbon in which the major existing forms of sulfur were SO₄ ^2? and S species. The oxidation of COS suggested that KOH in the micropores may play a catalytic role during the adsorption. On the other hand, we found that the desorption activation energy from KOHW was higher than that from AC by the CO₂-TPD spectra, which indicated the adsorption of CO₂ on KOH impregnated activated carbon was stronger. The strong adsorption could be attributed to the basic groups on the activated carbon surface. In conclusion, the activated carbon impregnated with KOH promises a good candidate for COS adsorbent.