Application of Nano Surfactant Modified Biosorbent as an Efficient Adsorbent for Dye Removal

In the current study, sorption of methylene blue dye (MB) from aqueous solutions, using sawdust modified with sodium dodecyl sulfate (SDS/SD) has been investigated. Sorption experiments were performed using batch and fixed-bed column systems. The effects of important parameters, such as pH, initial dye concentration, flow rate, and bed depth on the sorption of MB dye have been studied. Thomas and the bed-depth service time model (BDST) were applied for analysis of sorption data and estimating of sorption capacity. In order to drive adsorption isotherms, sorption experiments were conducted in batch mode and the treatment of the obtained data were carried out using the Langmuir and Freundlich equations. Based on the breakthrough analysis obtained from continuous sorption experiments, the highest column capacity of 129.68 mg g^?1 was obtained for the SDS/SD adsorbent. The results of this study indicated that surfactant-modified sawdust is much more effective for basic MB dye removal compared to untreated sawdust (SD) and the exhausted SDS/SD column can be easily regenerated using dilute HCl solution with high performance (>95%). The results of this study also indicated the successful applicability of the introduced adsorbent as a very efficient and cost effective adsorbent for the removal of cationic dye molecules from aqueous wastes.     

Magnetic CuFe2O4 Prepared by Polymeric Precursor Method as a Reusable Heterogeneous Fenton-like Catalyst for the Efficient Removal of Methylene Blue

The heterogeneous Fenton-like catalysts based on CuFe₂O₄ were prepared by polymeric precursor method at several annealing temperatures. The obtained catalysts were respectively characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, point of zero charge measurement, and vibrating sample magnetometer. The Fenton-like catalytic activity was evaluated via the oxidation of methylene blue with H₂O₂. The results show that the CuFe₂O₄ phase content and the particle size increase with the annealing temperatures whereas the surface OH groups and the surface acidity decrease. The prepared powders possess typical ferromagnetic properties which allow them to be easily recovered and reused. These catalysts also present highly catalytic activities for the oxidation of methylene blue, which is principally attributed to the catalysis of the CuFe₂O₄ phase. When the annealing temperature increased, the catalytic performance was reduced, corresponding to the increase of particle size and the decrease of surface OH groups.     

Silica Functionalized Magnetic Nickel Ferrite Nanoparticles as an Efficient Recyclable Catalyst for S-Arylation in Aqueous Medium

Silica coated NiFe₂O₄ NPs has been synthesized. It has been characterized by XRD, TEM, SEM-EDX and FT-IR. The catalytic activity of the Silica coated NiFe₂O₄ NPs has been tested for the S-arylation reaction in water with high yield. In this reaction water was used as the green solvent. The effects of solvents, reaction time and catalyst amount for the reaction was reported. This catalyst showed excellent catalytic activity and recyclability. The Silica coated NiFe₂O₄ NPs catalyst could be easily recovered by filtration and reused more than five times without appreciable loss of its initial activity.     

Removal of Pb2+, CrT,and Hg2+ Ions from Aqueous Solutions Using Amino-Functionalized Magnetic Nanoparticles

In this paper, a circular economy approach with the adsorption and desorption of heavy metal (HM) ions—i.e., lead (Pb²⁺), chromium (CrT), and mercury (Hg²⁺)—from aqueous solutions was studied. Specific and selective binding of HM ions was performed on stabilized and amino-functionalized iron oxide magnetic nanoparticles (γ-Fe₂O₃@NH₂ NPs) from an aqueous solution at pH 4 and 7. For this purpose, γ-Fe₂O₃@NH₂ NPs were characterized by thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), specific surface area (BET), transmission electron microscopy (TEM), EDXS, and zeta potential measurements (ζ). The effects of different adsorbent amounts (m_ads = 20/45/90 mg) and the type of anions (NO₃⁻, Cl⁻, SO₄²⁻) on adsorption efficiency were also tested. The desorption was performed with 0.1 M HNO₃. The results showed improvement of adsorption efficiency for CrT, Pb²⁺, and Hg²⁺ ions at pH 7 by 45 mg of g-Fe₂O₃@NH₂ NPs, and the sequence was as follows: CrT > Hg²⁺ > Pb²⁺, with adsorption capacities of 90.4 mg/g, 85.6 mg/g, and 83.6 mg/g, respectively. The desorption results showed the possibility for the reuse of γ-Fe₂O₃@NH₂ NPs with HNO₃, as the desorption efficiency was 100% for Hg²⁺ ions, 96.7% for CrT, and 91.3% for Pb²⁺.     

Poly(Amidoamine) Dendrimer Modified Superparamagnetic Nanoparticles as an Efficient Adsorbent for Cr(VI) Removal: Effect of High-Generation Dendrimer on Adsorption Performance

Journal of Inorganic and Organometallic Polymers and Materials - In this work, three different generations of Poly(amidoamine) dendrimers (PAMAM) decorated on magnetic Fe3O4 composites...     

改性沸石去除废水中Zn^2＋的试验

采用NaCl-MnO2联合的方式对天然斜发沸石进行改性,在静态条件下,对改性斜发沸石处理模拟含锌废水进行了试验研究,考察了吸附时间、吸附剂投量、Zn^2＋初始浓度和pH对改性斜发沸石吸附Zn^2＋的影响。结果表明：当温度为25℃、pH为5.0～6.0、Zn^2＋初始浓度≤50 m g/L时,按锌与改性斜发沸石质量比为1：40投加改性斜发沸石进行处理,Zn^2＋去除率可达90%以上,模拟含锌废水经改性沸石处理后,水中锌含量低于国家排放标准。改性斜发沸石对Zn^2＋的吸附规律符合Langm uir吸附等温线和准二级动力学模型,相关系数分别为0.927 5和0.999 2。     

Sulfonic Acid-Functionalized Silica-Coated Magnetic Nanoparticles as a Reusable Catalyst for the Preparation of Pyrrolidinone Derivatives Under Eco-Friendly Conditions

Silicon - The surface of silica-coated CoFe2O4 magnetic nanoparticles (CoFe2O4@SiO2), which is resistant to the oxidation due to silicone coating, was functionalized using chlorosulfonic acid and...     

Gold Nanoparticles Supported on the Periodic Mesoporous Organosilicas as Efficient and Reusable Catalyst for Room Temperature Aerobic Oxidation of Alcohols

Gold nanoparticles supported on the channels of a bifunctional periodic mesoporous organosilica, were found to be a highly efficient catalyst system for the aerobic oxidation of various types of alcohols into their corresponding aldehydes and ketones at room temperature. The catalyst showed no significant loss of efficiency for the aerobic oxidation of benzyl alcohol to give benzaldehyde after 7 reaction cycles.     

Tetramethylguanidine-Functionalized Fe3O4/ Chloro-Silane Core-Shell Nanoparticles: an Efficient Heterogeneous and Reusable Organocatalyst for Aldol Reaction

Silicon - Tetramethylguanidine supported onto magnetic Fe3O4 nanoparticles (MNPs-TMG) was prepared and identified by several techniques such as TEM, XRD, SEM, FT-IR and TGA analyses. The...     

乙二胺改性磁性壳聚糖微球制备及其对Cu2+和Pb2+吸附

以(NH4)2Fe(SO4)2.6H2O、NH4Fe(SO4)2.12H2O和壳聚糖为原料,经羟丙基化、氨基化,采用一步包埋法制备了一种新型的多氨基化磁性壳聚糖微球。并通过正交实验确定了改性磁性微球的最佳制备条件,即搅拌速度1200 r/min,壳聚糖用量3.0g,环氧氯丙烷用量5.0mL,乙二胺用量2.5mL。用荧光显微镜对其结构及形貌进行了观察。结果表明,Fe3O4磁性粒子已包埋了一层氨基化壳聚糖。改性磁性微球氨基含量为3.60mmol/g;呈较规则的球形,平均粒径为211.6nm。讨论在最佳条件下制备的壳聚糖微球对污水中Cu2+和Pb2+的吸附能力。     

Fe_3O_4磁性纳米颗粒外包腐植酸用于有效去除水中重金属

本研究合成了腐植酸(HA)包裹的Fe3O4纳米颗粒(Fe3O4/HA)并将其用于去除水中的重金属离子,包括Hg(I)、Pb(I)、Cd(I)和Cu(I)。以价格低廉、环境友好的铁盐和腐植酸为原料,通过共沉淀方法制备Fe3O4/HA。TOC和XPS的分析结果表明所制备的Fe3O4/HA中约含有11%(w/w)的叶酸,它是含O和N-官能团丰富的组分。TEM成像和激光颗粒尺寸分析证实所制备的Fe3O4/HA(Fe3O4内核约为10 nm)在水溶液中团聚并形成了平均水和半径约为140 nm的聚集体,饱和磁化强度为79.6 emu/g,这种Fe3O4/HA材料在低磁场梯度下几分钟内就可以从水溶液中分离。Fe3O4/HA对重金属离子的吸附在15分钟内就可以达到平衡,其吸附行为符合朗格缪尔吸附模型,且最大吸附容量在46.3~97.7 mg/g范围内。制备的Fe3O4/HA在自来水、天然水、0.1 M HCl和2 M Na OH的酸/碱溶液中都很稳定,Fe(≤3.7%)和HA(≤5.3%)的泄漏率很低。在最优条件下,Fe3O4/HA纳米材料能够去除天然水和自来水中超过99%的Hg(II)和Pb(II)以及超过95%的Cu(II)和Cd(II)。Fe3O4/HA吸附的重金属离子泄露回水溶液的量几乎可以忽略。     

Layered Nanocomposite 2D-TiO2 with Cu2O Nanoparticles as an Efficient Photocatalyst for 4-Chlorophenol Degradation and Hydrogen Evolution

Topics in Catalysis - New composites formed by layered hybrid TiO2(stearic acid) (LHTiO2) and, Cu2O nanoparticles were studied as photocatalysts that extend the response range to light visible for...     

改良MDEA脱碳工业应用报告

介绍改良ＭＤＥＡ脱碳的机理,工艺流程和生产运行情况,给出了操作数据。     

Ru Nanoparticles on Pr2O3 as an Efficient Catalyst for Hydrogen Production from Ammonia Decomposition

Catalysis Letters - Development of efficient catalysts for ammonia decomposition is crucial for hydrogen production from ammonia. Herein, Ru nanoparticles (NPs) highly dispersed on Pr2O3 (Ru/Pr2O3)...     

Hydrothermal Synthesis of Hierarchical Copper Oxide Nanoparticles and its Potential Application as Adsorbent for Pb(II) with High Removal Capacity

In this study, copper oxide nanoparticles with hierarchical morphologies (CuO) have been synthesized via a hydrothermal route. The morphology and microstructure of the as prepared samples were characterized by XRD, SEM, TEM, and SAED. CuO exhibited excellent performance for the removal of Pb(II) from aqueous solution. The effects of initial Pb(II) concentration and contact time on CuO were investigated from batch tests. The results indicate that the equilibrium adsorption data were best fitted by the Langmuir isothermal model, with the maximum adsorption capacity of 1428.5 mgg^?1 which is found to be one of the highest values reported elsewhere in the literature; adsorption kinetics follows the pseudo-second-order kinetic equation and intra-particle diffusion model. A possible adsorption mechanism was predicted by using FTIR, EDX techniques. Large adsorption capacity for heavy metal ion and effective regeneration ability suggesting CuO is a very promising adsorbent for metal ion removal and wastewater cleanup.     

Proline‐Functionalized Magnetic Core‐Shell Nanoparticles as Efficient and Recyclable Organocatalysts for Aldol Reactions

Novel magnetically tagged organocatalysts have been developed based on core‐shell nanoparticles consisting of magnetite cores and polyacrylate shells containing 4‐hydroxyproline moieties. These catalysts allow the performance of direct asymmetric aldol reactions of aromatic aldehydes with ketones in the presence of benzoic acid providing high yields and ees. Straightforward magnetic separation and recycling of a catalyst for up to 9 runs is possible without a significant loss of efficiency.