氢氧化镁改性硅藻土对阴离子染料的吸附性能研究

对硅藻土进行氢氧化镁改性以提高它对印染废水中染料的吸附性能.采用原位沉淀法由MgCl2及NaOH在硅藻土上制备了氢氧化镁,并用SEM、XRD对改性材料进行了表征;用分光光度法研究了它对阴离子染料的吸附性能.结果显示:改性硅藻土的染料吸附能力比原硅藻土及氢氧化镁都高;染料的吸附等温线采用Langmuir及Freundlich模型拟合,结果表明改性硅藻土对染料的吸附更符合Freundlich模型.     

聚丙烯酰胺/硅藻土复合材料处理染料废水

通过自制阴离子聚丙烯酰胺HPAM对硅藻土矿物改性制备一种有机无机复合吸附剂材料,采用SEM及FTIR技术对复合材料进行表征,并对3种模拟染料废水及2种真实印染污水进行脱色性能研究。结果显示,改性时较佳的HPAM用量在0.8%(质量分数)左右,复合后HPMA高聚物在硅藻土表面大孔内壁形成牙状絮体;通过与未改性硅藻土及颗粒活性炭对上述几种染料废水的处理效果对比,HPMA改性硅藻土复合材料对阳离子染料废水和真实印染废水均具有较高的脱色率。     

柠檬酸活化赤泥对亚甲基蓝染料废水的吸附净化作用

采用一种活化赤泥吸附剂用于水溶液中亚甲基蓝的吸附净化.考察吸附剂用量、pH值、亚甲基蓝浓度、吸附温度和吸附时间对活化赤泥吸附性能的影响规律.结果表明:采用稀柠檬酸活化处理可显著提高赤泥对染料分子的吸附效率;吸附率随吸附剂用量增加而增加,随初始亚甲基蓝浓度和温度升高而降低;测得活化赤泥对亚甲基蓝的最大吸附容量为30 mg/g,吸附过程符合Langmuir等温吸附模型;吸附动力学过程可用准二级动力学方程描述,计算出吸附过程的表观活化能为9.88 kJ/mol.对吸附过程焓和熵值的计算结果表明,活化赤泥对水溶液中亚甲基蓝染料的吸附是一个自发的放热过程.     

氧化锰改性硅藻土吸附剂的制备及其染料吸附性能

通过在硅藻土基体上原位生成氧化锰制备一种复合吸附剂材料,采用EDX、SEM及XRD等技术对该吸附剂进行了表征,并对3种染料废水的吸附性能进行研究。结果表明,制备过程中NaOH的前处理可在硅藻体表面形成带负电荷的孔位,有利于氧化锰的复合与分散;复合吸附剂的粒径约11.23μm,其表面的无定形结构氧化锰呈准球形,粒径约为100nm;对染料废水的脱色率结果显示,该复合吸附剂对阳离子和活性染料均具有良好的吸附性能。     

共沉淀法制备磷酸盐纳米颗粒及其对甲基蓝吸附性能研究

采用共沉淀方法室温下制备分别含有Ca和Ba的磷酸盐纳米颗粒,并作为吸附剂用于水溶液中甲基蓝染料的去除。实验通过研究不同接触时间和不同初始浓度的甲基蓝溶液对上述两种吸附剂吸附甲基蓝量的影响,对吸附过程进行等温吸附线和吸附动力学分析。结果表明:在20min内,两种吸附剂都达到吸附平衡,而且对甲基蓝的吸附符合准二级动力学方程。磷酸盐对甲基蓝的吸附性能满足Langmuir吸附等温线方程。     

磁性Fe3O4/活性炭对电镀废水中Cr(Ⅵ)吸附性能的研究

目的获得吸附性能、磁分离性能和再生性能较佳的磁性Fe_3O_4/活性炭吸附剂(MAC)。方法通过化学共沉淀法制备出磁性Fe_3O_4/活性炭吸附剂。采用X-射线衍射仪(XRD)和傅里叶变换红外光谱仪(FTIR)对活性炭进行表征。使用磁性Fe_3O_4/活性炭吸附电镀废水中的Cr(Ⅵ),考察吸附剂用量、吸附pH值和吸附时间对吸附性能的影响,并研究了吸附动力学模型。利用磁铁对磁性Fe_3O_4/活性炭进行了回收。结果制备的磁性Fe_3O_4/活性炭中含有纯度较高的立方相磁性Fe_3O_4粒子。在温度为25℃、pH=3、吸附时间为120 min、吸附剂用量为0.15 g时,对Cr(Ⅵ)的去除率最高,达到了97.44%,吸附动力学符合拟二级动力学模型。电镀废水中共存阳离子会使吸附性能增强,共存阴离子会使吸附性能降低。磁性Fe_3O_4/活性炭的回收率达93.58%,6次解吸-再生后,吸附量仍较高,为27.17 mg/g。结论磁性Fe_3O_4/活性炭吸附剂对电镀废水中的Cr(Ⅵ)具有较高的去除率,吸附剂回收方法简单,回收率高,具有较好的应用前景。     

化学气相沉积法改性ACFs及其去除溶液中甲基橙的应用(英文)

通过化学气相沉积法(CVD)对粘胶基活性炭纤维(ACFs)进行表面改性,利用比表面积、SEM、孔径分布和红外光谱等分析方法对样品进行表征。通过吸附实验研究改性ACFs对溶液中甲基橙的吸附行为。结果表明,吸附数据较符合Langmuir等温线模型;准二级动力学方程能够较好地反映改性ACFs对溶液中甲基橙的吸附动力学;颗粒间扩散为控制步骤,但并非唯一控制步骤。经计算获得的热力学参数包括ΔG、ΔH和ΔS,表明吸附为自发的放热物理吸附过程。从红外光谱分析可知,氢键作用是改性ACFs吸附甲基橙的主要吸附机理。     

铜和金硫代硫酸盐在活性炭上的吸附机理（英文）

研究活性炭对铜和金硫代硫酸盐的吸附机理。铜和金硫代硫酸盐在活性炭上的吸附动力学均符合准二级动力学模型。活性炭对铜硫代硫酸盐的吸附等温线符合Freundlich模型，而对金硫代硫酸盐的吸附等温线符合Langmuir模型。负载活性炭的键合特性分析表明，活性炭对铜和金的吸附机理不同。在实验条件下，活性炭对铜的吸附量达到79.04 mg/g，比金的吸附量高出约2个数量级。这意味着由于金的吸附量低以及铜和硫代硫酸盐的竞争吸附，用活性炭从硫代硫酸盐浸出液中回收金将面临很大的挑战。     

活性炭陶瓷复合材料的苯吸附特性

用硅藻土及木质活性炭为主要原料制备活性炭陶瓷复合材料,通过含炭量、碘吸附值、体积密度、气孔率和抗压强度测试确定最佳制备工艺条件。探讨该活性炭陶瓷复合材料对苯的吸附特性影响,对比分析了活性炭不同添加量、不同烧结温度及不同环境温度对材料苯吸附性能的影响。结果表明适宜的硅藻土与活性炭比值为7∶3,烧成温度为800℃,此时该材料的气孔率达到52.48%,体积密度为1.067 g/cm3,抗压强度为10.466 MPa,碘吸附值为291.24 mg/g,含炭量为25.62%,苯吸附率为9.56%,比表面积为290.72 m2/g。活性炭陶瓷复合材料的苯醛吸附率随着活性炭含量的增加明显加大,但受外界环境温度影响较小。     

高锰酸钾改性黄芪废渣活性炭对Cd~(2+)的吸附（英文）

以黄芪废渣为原料,用KOH为活化剂制备黄芪废渣活性炭,并用KMnO_4改性,改性前后的黄芪废渣活性炭用于对水溶液中Cd~(2+)的吸附。采用扫描电子显微术、比表面积测定、X射线衍射、红外光谱和贝母滴定等方法对改性前后的黄芪废渣活性炭进行表征;通过静态吸附实验考察改性前后黄芪废渣活性炭对水溶液中Cd~(2+)的吸附性能。结果表明,KMnO_4改性后活性炭表面含氧官能团增加,MnO_2沉积到活性炭表面。改性前后的黄芪废渣活性炭对Cd~(2+)的吸附符合准二级动力学方程,等温吸附更符合Langmuir模型,改性前后的黄芪废渣活性炭对Cd~(2+)的饱和吸附量分别是116.96和217.00mg/g。KMnO_4显著改变了黄芪废渣活性炭的物理化学性质和表面结构,改性后的黄芪废渣活性炭对Cd~(2+)的吸附能力明显提高。     

Adsorption of Cd2+ in aqueous solutions using KMnO4-modified activated carbon derived from Astragalus residue

Activated carbon obtained from Astragalus residue was chemically activated by KOH and modified with KMnO₄. The samples were characterized by N₂ adsorption, Fourier transform infrared spectroscopy, X-ray diffractometry, scanning electron microscopy, and Boehm titration. Accordingly, the original and modified carbon materials were used for the removal of Cd²⁺ from aqueous solution by batch adsorption experiments. Results showed that the contents of oxygen-containing functional groups increased, and MnO₂ was nearly uniformly deposited on the surface of activated carbon after modification by KMnO₄. The adsorption kinetics was described by pseudo-second order model. Langmuir model fitted the adsorption-isotherm experimental data of Cd²⁺ better than the Freundlich model. The maximum adsorption capacities of the activated carbon before and after modification for Cd²⁺ were 116.96 and 217.00 mg/g, respectively. KMnO₄ considerably changed the physicochemical properties and surface texture of activated carbon and enhanced the adsorption capacity of activated carbon for Cd²⁺.     

Effect of acidic surface functional groups on Cr(Ⅵ) removal by activated carbon from aqueous solution

The activated carbon with high surface area was prepared by KOH activation.It was further modified by H2SO4 and HNO3 to introduce more surface functional groups.The pore structure of the activated carbons before and after modification was analyzed based on the nitrogen adsorption isotherms.The morphology of those activated carbons was characterized using scanning electronic microscopy (SEM).The surface functional groups were determined by Fourier transform infrared spectroscopy (FTIR).The quantity of those ...     

Enhanced Cu(Ⅱ) adsorption by orange peel modified with sodium hydroxide

Copper adsorption by orange peel, which was chemically modified with sodium hydroxide, was investigated. The adsorbent was characterized using surface area analyzer, infrared spectroscopy and scanning electron microscopy. Total negative charge and zeta potentials on the adsorbent surface were determined. Equilibrium isotherms and kinetics were obtained and the effects of solution pH value, adsorbent concentration and temperature were studied in batch experiments. Column experiments were performed to study practical applicability, and breakthrough curves were obtained. Equilibrium is well described by Langmuir and Freundlich isotherms, and kinetics is found to fit pseudo-second order type adsorption kinetics. According to Langmuir equation, the maximum adsorption capacity for Cu(II) is 50.25 mg/g at pH value of 5.3. The results show additional chemical modification of the adsorbent by NaOH and the increased adsorption capacity.     

表面处理活性炭及其对二氧化碳吸附性能研究

目的提高活性炭对二氧化碳的吸附性能。方法用二乙烯三胺浸渍方法对活性炭进行表面处理,利用X射线衍射仪对活性炭表面处理前后进行物相分析,利用全自动比表面及空隙度分析仪,对活性炭表面处理前后进行比表面积和孔结构分析。最后对活性炭表面处理前后进行吸附实验,并对其进行理论分析。结果表面处理后,活性炭中的碳由三方晶系变为六方晶系,并且活性炭表面增加了氨基。活性炭的比表面积增加了2.13倍;微孔容增加了1.80倍,由0.056 cm~3/g增加至0.157 cm~3/g;总孔容增加了3.24倍,由0.078cm~3/g增加至0.331 cm~3/g;中孔容增加量为0.152 cm~3/g;平均孔径减小了0.27 nm,由7.14 nm减少至6.87 nm。活性炭的吸附量由0.92 mmol/g增加至3.55 mmol/g,是表面处理前的3.86倍,其饱和吸附时间从10 min增加至40 min。结论此方法可以有效提高活性炭的吸附性能。     

Kinetics of liquid-phase adsorption of organic dye on activated carbons

The kinetic parameters of liquid-phase adsorption of a model organic dye, such as methyl orange, from aqueous solution on carbon sorbents were determined under static conditions. Activated carbon and carbon modified with carbon nanotubes synthesized by chemical vapor deposition on metal oxide catalysts were used as experimental materials. It was found that the presence of carbon nanomaterial in the structure of activated carbon intensifies the sorption process and increases the equilibrium adsorption in 2.1 times. The calculated values of the adsorption rate constants showed a 1.5 times higher rate of the extraction process on modified carbons than on standard materials. In addition, the sorption of organic dye was adequately described by the pseudosecond order model, thus, implying a significant contribution of the chemical interaction between adsorbate and adsorbent to the sorption process.     

改性活性炭吸附金的性能

为了改善活性炭的吸附性能,以硫脲和甲醛为主要原料对活性炭进行了改性,并对改性活性炭的吸附性能进行了研究.静态吸附实验表明:改性活性炭在酸性环境中比在碱性溶液中对Au3 的吸附能力要强;无论是对金的吸附容量还是在含有重金属离子(Cu2 、Ni2 和Zn2 )的混合溶液中吸附金的选择性,改性活性炭都比一般活性炭强得多;改性活性炭几乎可将混合溶液中Au3 完全吸附,而对重金属离子Ni2 和Cu2 的吸附率不到1/3.改性活性炭对金的吸附符合Langmuir单分子层吸附规律.     

Physicochemical and adsorption-structural properties of diatomite modified with aluminum compounds

A selective sorbent based on the diatomite of local origin modified with aluminum compounds has been studied by the methods of powder X-ray diffraction; FTIR; and differential thermal, adsorption-structural (BET), and chemical analyses. The surface modification of diatomite is carried out by heating it in an NaOH solution and its subsequent treatment with a solution of aluminum salt and ammonia. The amorphous surface silica partially dissolves during the treatment with NaOH and forms an aluminosilicate compound at the addition of an aluminum salt. The obtained material is deposited both on the surface of the diatomite and on the inner surface of the macro- and larger mesopores, which leads to the development of the specific surface area of 81.8 m²/g, which is 2.5 times larger than the corresponding value in the initial diatomite (37.5 m²/g). The precipitated aluminosilicate compound with the concentration equal to 0.34 g of Al/g of aluminosilicate contributes to the development of a porous structure in the treated diatomite, so the volume of the mesopores increases from 0.029 to 0.079 cm³/g and that of the micropores from 0.012 to 0.027 cm³/g. The qualitative changes in the composition of the obtained sorbent are confirmed by the emergence of new lines in the X-ray diffraction patterns, which are characteristic for aluminosilicates, and additional peaks in the infrared spectra corresponding to the stretching vibrations of Si-O-Al. The selectivity of the obtained adsorbent with respect to fluoride ions increases significantly, specifically, its adsorption capacity increases from 8.9 to 57.6 mg of F/g at the initial fluorine concentration equal to 0.15 mol/L.