硝酸改性活性炭的制备及其对Cr（Ⅵ）

利用硝酸对颗粒活性炭进行改性,处理含铬废水,并考察了吸附时间、溶液pH、吸附剂加入量对改性活性炭吸附Cr（Ⅵ）效果的影响。实验结果表明：经过硝酸氧化改性的活性炭比表面积有所增加,官能团总量增加明显;吸附剂对Cr（Ⅵ）的去除率随振荡时间的增加而增加;对于质量浓度为10mg/L的100mLCr（Ⅵ）溶液,当溶液pH为中性,30%（体积分数）硝酸改性的颗粒活性炭的加入量为0.4g,其对Cr（Ⅵ）的最大去除率为98%。     

挥发性有机物的物化性质与活性炭饱和吸附量的相关性研究

采用kc-4．0型颗粒活性炭对甲苯、对二甲苯、乙酸甲酯、乙酸乙酯、乙醇、正丙醇进行吸附实验,研究挥发性有机物的物化性质与活性炭饱和吸附量之间的相关性。实验结果表明,活性炭对乙酸甲酯、乙醇和正丙醇的吸附性能较差,对乙酸乙酯、甲苯和对二甲苯的的吸附性能较好,饱和吸附量最大的是甲苯（达312．92mg／g）,饱和吸附量最小的是乙酸甲酯（为224．93mg／g）。6种挥发性有机物的吸附等温线用Langmuir方程进行拟合,效果良好。挥发性有机物的比蒸发速度、饱和蒸气压和电离势能与活性炭饱和吸附量具有显著的相关性。比蒸发速度越快、饱和蒸气压越高或电离势能越大,活性炭饱和吸附量越小。     

超临界氨水改性活性炭及其对CO2的吸附性能

采用超临界氨水改性活性炭(AC),考察了改性AC对CO2的吸附性能,表征了改性前后AC的表面结构和化学性质.实验结果表明,改性温度为150℃制备的改性AC具有最高的CO2吸附量,25℃时吸附量从改性前的0.979 mmol/g增至1.291 mmol/g,增加了约30％.表征结果显示:改性后AC表面成功负载了含氮基团;...     

氧化改性对活性炭吸附二苯并噻吩的影响

采用硝酸作为氧化剂,对树脂基球形活性炭(RCS)表面进行氧化改性,分别考察了氧化时间、氧化温度及硝酸浓度对改性RCS吸附脱除油品中二苯并噻吩(DBT)的性能影响.通过N2吸附、Boehm滴定和热重分析等手段对改性前后的RCS进行表征.实验结果表明:较为经济有效的改性工艺条件为硝酸浓度10 mol/L,氧化温度60℃,氧化时间3h;改性RCS的比表面积和总孔体积都有所下降;硝酸改性后,RCS的表面酸性基团含量由0.83 mmol/g提高至3.85 mmol/g;改性前后RCS吸附DBT的等温线可较好地用Freundlich方程进行拟合.     

酸改性碳材料吸附溶液中U(Ⅵ)

以活性炭、碳纳米管和石墨烯为基体材料,分别采用醋酸、硫酸和硝酸对其进行改性,运用BET、FTIR、SEM等技术对材料进行了表征,详细考察了其对溶液中U(Ⅵ)的吸附性能。实验结果表明：醋酸改性的效果最好,醋酸改性活性炭对U(Ⅵ)的吸附具有更大优势;在吸附时间90 min、吸附剂加入量1.0 g/L、U(Ⅵ)初始质量浓度50 mg/L、醋酸改性活性炭的溶液pH为7、醋酸改性碳纳米管和石墨烯的溶液pH为8的最优吸附条件下,醋酸改性的活性炭、碳纳米管、石墨烯的U(Ⅵ)吸附率分别为90.13%,89.82%,82.08%。表征结果显示：吸附剂对U(Ⅵ)的吸附性能主要取决于其表面羧基、羟基等含氧官能团的数量;吸附剂对U(Ⅵ)的吸附具有化学吸附特征。     

白腐菌改性的中药渣对Cr（Ⅵ）的吸附性能

以白腐菌的典型菌种黄孢原毛平革菌为改性菌种,对中药渣进行改性处理,研究了改性中药渣对Cr（Ⅵ）的吸附性能。采用SEM技术对改性中药渣进行表征。研究了废水pH、改性中药渣加入量、吸附温度和吸附时间对Cr（Ⅵ）吸附效果的影响。表征结果显示,中药渣经过改性后表面出现许多孔隙,比表面积增大,为吸附Cr（Ⅵ）提供了更多的吸附位。实验结果表明：在初始Cr（Ⅵ）质量浓度50 mg/L、改性中药渣加入量5 g/L、废水pH 2、吸附温度45 ℃、吸附时间20 h的条件下,改性中药渣对Cr（Ⅵ）的去除率达99.5%,吸附量可达9.82 mg/g;改性中药渣对Cr（Ⅵ）的吸附等温线符合Langmuir等温吸附方程和Freundlich等温吸附方程;准二级动力学方程能很好地对改性中药渣吸附Cr（Ⅵ）的数据进行拟合。     

酒石酸改性活性炭对烟气脱硝钴氨吸收液中Co~(3+)的催化还原

废气中的NO和SO2可通过钴氨吸收液去除,但钴氨吸收液中的Co~(2+)易被氧化成Co~(3+)而失去脱硝能力。为了实现Co~(2+)的再生,采用酒石酸溶液对活性炭进行改性,提高其对Co~(3+)的催化还原能力,考察了活性炭催化剂改性及活化条件对钴氨吸收液Co~(3+)还原率及NO去除率的影响。实验结果表明:在酒石酸溶液浓度为1.5 mol/L、改性时间为18 h、活化温度为400℃、活化时间为4 h的条件下,改性活性炭的催化性能最佳;Co~(3+)还原率为67.5%,比原炭提高了11.9百分点;对应的钴氨吸收液的NO去除率为86.0%,比原炭提高了26.0百分点。pHpzc测定、Boehm滴定和BET表征结果表明,与原炭相比,改性活性炭酸性增强,羧基和内酯基含量增加,微孔数目增加,比表面积增大。这些表面特性的改变使改性活性炭的催化性能得到改善。     

改性生物炭对Sb（Ⅲ）的吸附行为及机理

采用氯化铝和高锰酸钾对生物炭进行改性,研究生物炭表面Sb（Ⅲ）的吸附规律及吸附机理。实验结果表明,在固液比为2.5 g/L、pH为4、吸附温度为25 ℃、吸附时间为240 min、溶液初始质量浓度为10.0 mg/L时,BC、Al-BC和KMnO₄-BC对Sb（Ⅲ）的平衡吸附量分别为1.13,2.12,2.98 mg/g。KMnO₄-BC和Al-BC的吸附机理不同,KMnO₄-BC等温吸附曲线符合Langmuir等温模型,吸附动力学过程遵循拟二级动力学方程;Freundlich模型和拟一级动力学方程更适合描述Al-BC对Sb（Ⅲ）的吸附。3种生物炭的吸附过程都以物理吸附为主,同时有化学吸附的参与。BET比表面积与FTIR分析结果表明,Al-BC吸附量大主要得益于比表面积及孔体积的增大。     

水热法表面改性陶粒及其对水中磷的吸附性能

采用水热法制备碳改性陶粒和铁/碳改性陶粒,对改性陶粒表面进行了表征,研究了改性陶粒对废水中磷的吸附效果。表征结果显示,改性后陶粒形貌更规则,比表面积增加,有机官能团种类增多。吸附实验结果表明,碳改性陶粒和铁/碳改性陶粒在初始磷质量浓度为5 mg/L、pH分别为6和5、陶粒投加量为0.03 mg/L的条件下,于35℃下吸附8 h,磷的去除率分别达到97.28%和93.10%,剩余磷质量浓度分别为0.136 mg/L和0.345 mg/L;Langmuir等温吸附模型和准二级动力学方程更适合描述两种改性陶粒对磷的吸附过程,且改性后陶粒均具有良好的解吸能力,解吸率随解吸剂浓度的增加而增大。     

负载金属改性活性炭纤维的脱硫性能

采用浸渍法将金属负载到活性炭纤维(ACF)上对其进行改性,研究了负载金属改性ACF对模型油(二苯并噻吩-正辛烷)的吸附脱硫效果,对比了不同单金属和复合金属盐改性ACF的脱硫性能。实验结果表明:Ag和Zn复合改性的ACF具有最好的脱硫性能;在吸附温度为40℃,吸附时间为2.5 h,油剂质量比为21.5的优化条件下,脱硫率高达97.55%,且具有良好的重复利用性。     

响应面法优化阴阳极同时作用电化学法处理染料废水

在自制电化学反应器中,以甲基橙模拟染料废水为处理对象,采用Box-Behnken Design响应面法研究了影响阴阳极同时作用电化学法处理染料废水的因素及其交互作用。实验得出各因素对废水脱色率影响的大小顺序为：电流密度> Fe³⁺浓度>Cl^-浓度。各因素之间的交互作用对废水脱色率影响的大小顺序为：电流密度和Fe³⁺浓度>电流密度和Cl^-浓度>Fe³⁺浓度和Cl^-浓度。优化结果表明：Fe³⁺浓度为1.02 mmol/L、Cl^-浓度为10.96 mmol/L、电流密度为11.52 mA/cm²时,最佳脱色率为94.67%。阴阳极同时作用电化学法对甲基橙去除效果显著。     

Experimental and Modeling Studies for the Removal of Crystal Violet Dye from Aqueous Solutions using Eco-friendly <Emphasis Type="Italic">Gracilaria corticata</Emphasis> Seaweed Activated Carbon/Zn/Alginate Polymeric Composite Beads

This research article describes, an eco-friendly activated carbon prepared from the Gracilaria corticata seaweeds which was employed for the preparation of biodegradable polymeric beads for the efficient removal of crystal violet dye in an aqueous solution. The presence of chemical functional groups in the adsorbent material was detected using FTIR spectroscopy. The morphology and physical phases of the adsorbent materials were analyzed using SEM and XRD studies respectively. Batch mode dye adsorption behavior of the activated carbon/Zn/alginate polymeric beads was investigated as a function of dosage, solution pH, contact time, initial dye concentration and temperature. Maximum dye removal was observed at a pH of 5.0, 1 g of adsorbent dosage with 60 mg/L dye concentration, 50 min of contact time and at 30 °C. The equilibrium modeling studies were analyzed with Freundlich and Langmuir adsorption isotherms and the adsorption dynamics was predicted with Lagergren’s pseudo-first order, pseudo-second order equations and intra particle diffusion models. The process of dye removal followed a pseudo second-order kinetics rather than pseudo first order. The thermodynamic parameters like standard Gibbs free energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°) were determined and the results imply that the adsorption process was spontaneous, endothermic and increases the randomness between the adsorbent and adsorbate. The results from the experimental and correlation data reveal that the Gracilaria corticata activated carbon/Zn/alginate polymeric beads have proved to be an excellent adsorbent material for the removal of CV dye.     

Removal of Cr6 + and Ni2+ from aqueous solution using bagasse and fly ash

Raw bagasse and fly ash, the waste generated in sugar mills and boilers respectively have been used as low-cost potential adsorbents. Raw bagasse was pretreated with 0.1N NaOH followed by 0.1N CH3COOH before its application. These low-cost adsorbents were used for the removal of chromium and nickel from an aqueous solution. The kinetics of adsorption and extent of adsorption at equilibrium are dependent on the physical and chemical characteristics of the adsorbent, adsorbate and experimental system. The effect of hydrogen ion concentration, contact time, sorbent dose, initial concentrations of adsorbate and adsorbent and particle size on the uptake of chromium and nickel were studied in batch experiments. The Sorption data has been correlated with Langmuir, Freundlich and Bhattacharya and Venkobachar adsorption models. The efficiencies of adsorbent materials for the removal of Cr(VI) and Ni(II) were found to be between 56.2 and 96.2% and 83.6 and 100%, respectively. These results were obtained at the optimized conditions of pH, contact time, sorbent dose, sorbate concentration of 100 mg/l and with the variation of adsorbent particles size between 0.075 and 4.75 mm. The order of selectivity is powdered activated carbon > bagasse > fly ash for Cr(VI) removal and powdered activated carbon > fly ash > bagasse for Ni(II) removal.     

活性炭吸附缓冲非稳态VOCs研究进展

活性炭类吸附剂可以有效地缓冲挥发性有机物(VOCs)的浓度负荷波动。综述了活性炭对非稳态VOCs吸附缓冲的作用原理及类型,从吸附剂、吸附质、进气性质和设备及操作条件等方面讨论了影响吸附缓冲性能的因素,并对今后该领域的研究方向提出了展望。指出:应当进一步研究吸附剂和吸附质的交互作用、波动负荷的影响以及VOCs在活性炭中的迁移扩散现象;同时,通过深层次的实验测试和模型模拟为反应器的设计和操作参数的估算提供指导。     

轻烃类VOCs在活性炭上的动态吸附行为

采用BET,XRD,FTIR技术对两类椰壳活性炭进行了表征,考察了空速和吸附温度对正戊烷和正己烷动态吸附穿透容量(DPC)及穿透时间的影响,并对正戊烷和正己烷的二元竞争吸附过程进行了研究。结果表明:两类活性炭材料的组成和官能团结构相似,具有大量微孔的片状活性炭(FAC)有利于轻烃类VOCs的吸附;采用FAC吸附正己烷时,DPC对空速和温度变化不敏感;二元竞争吸附过程中,开始阶段正戊烷和正己烷同时被吸附,随后已被吸附的正戊烷被强吸附质正己烷部分置换,直至正己烷吸附饱和,与一元吸附相比,正己烷的DPC和饱和吸附容量略有增加,正戊烷的DPC和饱和吸附容量大幅降低。     

Adsorption of malachite green on groundnut shell waste based powdered activated carbon

In the present technologically fast changing situation related to waste management practices, it is desirable that disposal of plant waste should be done in a scientific manner by keeping in view economic and pollution considerations. This is only possible when the plant waste has the potential to be used as raw material for some useful product. In the present study, groundnut shell, an agricultural waste, was used for the preparation of an adsorbent by chemical activation using ZnCl2 under optimized conditions and its comparative characterisation was conducted with commercially available powdered activated carbon (CPAC) for its physical, chemical and adsorption properties. The groundnut shell based powdered activated carbon (GSPAC) has a higher surface area, iodine and methylene blue number compared to CPAC. Both of the carbons were used for the removal of malachite green dye from aqueous solution and the effect of various operating variables, viz. adsorbent dose (0.1-1 g l(-1)), contact time (5-120 min) and adsorbate concentrations (100-200 mg l(-1)) on the removal of dye, has been studied. The experimental results indicate that at a dose of 0.5 g l(-1) and initial concentration of 100 mg l(-1), GSPAC showed 94.5% removal of the dye in 30 min equilibrium time, while CPAC removed 96% of the dye in 15 min. The experimental isotherm data were analyzed using the linearized forms of Freundlich, Langmuir and BET equations to determine maximum adsorptive capacities. The equilibrium data fit well to the Freundlich isotherm, although the BET isotherm also showed higher correlation for both of the carbons. The results of comparative adsorption capacity of both carbons indicate that groundnut shell can be used as a low-cost alternative to commercial powdered activated carbon in aqueous solution for dye removal.     

Removal of fluoride from water using aluminum-modified activated carbon prepared from khat (Catha edulis) stems

This study investigated the fluoride removal efficiency and adsorption of a low-cost adsorbent prepared using aluminum-modified activated carbon from khat (Catha edulis) in a batch-mode reactor. The operating factors, including pH, adsorbent dose, and fluoride initial concentration, were optimized using the Box Behnken design of response surface methodology. The correlation coefficient (R²) for the removal of fluoride was found to be 0.93, showing the validity of the developed quadratic model. The results showed that, under optimized conditions of an adsorbent dose of 2.47 g/L, an initial fluoride concentration of 2.1 mg/L, an initial pH 6.08, and 60 min, 90% fluoride reduction was achieved. Meanwhile, the adsorption isotherm and kinetics followed the Langmuir adsorption model and the Pseudo second model, respectively, with a monolayer adsorption capacity of 0.3065 mg/g. On the other hand, Fourier transform infrared spectroscopy and scanning electron microscopy analyses revealed the formation of major peaks of components such as hydroxyl and carboxylic acids. The same optimum treatment conditions (adsorbent dose of 2.47 g/L, initial pH 6.08, and treatment time of 60 min) managed to remove low initial fluoride concentrations of 3.67 and 4.33 mg/L from real groundwater by 72.84% and 70.37%, respectively. The modified adsorbent prepared in this study successfully treat the low fluoride concentration to a level recommended by WHO for drinking water.     

活化后钾改性正硅酸锂吸附CO2的性能评价及动力学研究

制备了钾改性正硅酸锂(K-Li4SiO4),并对其进行了自活化,考察了活化后K-Li4SiO4吸附剂在不同温度和CO2浓度气氛中吸附CO2的性能及动力学行为。总体而言,吸附剂的CO2吸附能力随着温度的升高、CO2浓度的增加而提升。在700℃、100%体积分数CO2气氛中吸附剂的吸附量最大,可达7.9 mmol/g,吸附剂的利用率为95.2%。利用双指数模型能够很好地描述吸附剂在各个温度以及各个CO2浓度气氛下的CO2吸附过程。吸附活化能随着CO2气氛浓度的升高而降低,CO2体积分数为20%,50%,100%时的吸附活化能分别为26448,14035,6178 J/mol。