scholarly journals Preparation of Pb(II) ion-imprinted polymers and their application in selective removal from wastewater

2017 ◽  
Vol 36 (1-2) ◽  
pp. 774-787 ◽  
Author(s):  
Xianglong Ao ◽  
Hongzhi Guan
Keyword(s):  
Nicotinic Acid ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Industrial Wastewater ◽  
Removal Rate ◽  
Energy Dispersive Spectrometer ◽  
Lead Ion ◽  
Order Kinetic ◽  
Ion Imprinted ◽  
Ion Imprinted Polymers

A novel hydrophilic Pb(II) ion-imprinted polymer (Pb(II)-IIP) was synthesized using lead ion as a template ion, 2-(allyl sulfur) nicotinic acid as functional monomer by precipitation polymerization method. The adsorption capacity of Pb(II)-IIP to Pb(II) was saturated at 16 min, and the adsorption process is consistent with the quasi-second-order kinetic adsorption model. The optimum adsorption capacity of Pb(II)-IIP was 29.67 mg/g, about triple than Pb(II)-NIP, and the adsorption is in accordance with the Langmuir isothermal model, which indicates that it is dominated by single layer chemical adsorption. X-ray Photoelectron Spectroscopy (XPS) and Energy Dispersive Spectrometer (EDS) data confirm that the chelate ratio of Pb(II) to 2-(allylthio) nicotinic acid is 1:2. In the presence of competing ions, the adsorption capacity of Pb(II)-IIP to Pb(II) is much larger than that of other ions, which indicates that Pb(II)-IIP is less disturbed by competitive ions. The experiment of application of practical wastewater shows that Pb(II)-IIP has a Pb(II) removal rate of 97.2% or more in practical industrial wastewater, which is in accordance with national emission standards. It is proved that Pb(II)-IIP is an effective material to remove Pb(II) in industrial wastewater.

scholarly journals Preparation of Nitrosulfonated Humic Acid-based Ion-imprinted Polymer and Study on Its Adsorption Properties

2021 ◽  
Author(s):  
An Wang ◽  
Xiaoran Sun ◽  
Yinuo Yan ◽  
Simeng Bian ◽  
Kaili Fan ◽  
...  
Keyword(s):  
Humic Acid ◽  
Crosslinking Agent ◽  
Organic Polymer ◽  
Lead Ion ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Ion Imprinted Polymer ◽  
Imprinted Polymer ◽  
Ion Imprinted ◽  
Ion Imprinted Polymers

Abstract Ion imprinted polymer, a kind of high molecular organic polymer, which can separate and enrich various metal ions in water by changing the adsorption conditions. Used humic acid as raw materials, used HNO3 and H2SO4 as modifiers to synthesize nitrosulfonated humic acid, then used it as substrate, NIPAM as the functional monomer, Pb2+ as the template ion, MBA as the crosslinking agent, K2S2O8 and NaHSO3 as initiators to prepare lead ion imprinted polymers after cross-linking reaction. Used SEM, FT-IR, TG-DSC to characterize the obtained product, and explored the structure and performance of the product. The adsorption performance of IIPs (NSA/NIPAM) was studied by ultraviolet-visible spectrophotometry (UV-vis). The results show that the maximum adsorption capacity of IIPs (NSA/NIPAM) for Pb2+ is 81.33 mg/g, the optimal number of cycles of IIPs (NSA/NIPAM) is 10, In the presence of competing ions Cu2+ and Cd2+, selectivity coefficients are 18.04 (Pb2+/Cu2+) and 19.39 (Pb2+/Cd2+). The results of simulating the thermodynamic adsorption process of the polymers with Langmuir and Freundlich thermodynamic adsorption models show that the imprinted polymer conform to the second-order kinetic model and the Langmuir thermodynamic model, and belong to monolayer chemisorption.

scholarly journals Adsorption of Lead Ion from Wastewater Using Non-Crystal Hydrated Calcium Silicate Gel

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 842
Author(s):  
Shijie Liu ◽  
Suping Cui ◽  
Hongxia Guo ◽  
Yali Wang ◽  
Yan Zheng
Keyword(s):  
Adsorption Capacity ◽  
Calcium Silicate ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Precipitation Method ◽  
Lead Ion ◽  
Order Kinetic ◽  
Hydrated Calcium Silicate ◽  
Hydrated Calcium

In order to obtain low-cost and excellent adsorption materials, this paper used calcium acetate and water glass as raw materials to synthesis hydrated calcium silicate gel by precipitation method. The performance and structure of hydrated calcium silicate gel were systematically studied by X-ray photoelectron spectroscopy, fourier transform infrared spectroscopy, specific surface area analyzer and scanning electron microscope. Studies have shown that, non-crystal hydrated calcium silicate gel (CSH) were successfully prepared, and the removal rate of lead ion using CSH reached more than 90%. The adsorption process is consistent with the pseudo-second-order kinetic model and Langmuir adsorption isotherm model, and the limit adsorption capacity reaches 263.17 mg·g−1. The acid treatment experiment proved that the adsorption capacity of lead ion using CSH was satisfactory, and the adsorption rate remained at >60% after 5 cycles. The research may provide a low-cost, high-efficiency and high stability adsorbent.

Preparation of Novel Ag–Si–TiO2 Composite and Research on Its Photocatalytic Degradation of Formaldehyde

2021 ◽  
Vol 13 (3) ◽  
pp. 371-380
Author(s):  
Yongjun Wu ◽  
Nina Xie ◽  
Lu Yu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Removal Rate ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Formaldehyde Concentration ◽  
Order Kinetic ◽  
Solution Ph ◽  
Visible Absorption ◽  
X Ray ◽  
Co Doped

A novel Ag–Si–TiO2 composite was prepared via sol–gel method for removing residual formaldehyde in shiitake mushroom. The structure of Ag–Si–TiO2 composite was characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses. Ultraviolet-visible absorption spectroscopy (UV-Vis) and N2 adsorption-desorption tests showed that Ag and Si co-doped decreased the band gap, the Brunauer-Emmett-Teller (BET) specific surface area of the samples increased and the recombination probability of electron-hole pairs (e--h+) reduced. Effect on removal rate of formaldehyde with different Ag-Si co-doped content, formaldehyde concentration and solution pH were investigated, and the results showed that 6.0 wt%Ag-3.0 wt%Si-TiO2 samples had an optimum catalytic performance, and the degradation efficiency reached 96.6% after 40 W 365 nm UV lamp irradiation for 360 min. The kinetics of formaldehyde degradation by Ag–Si–TiO2 composite photocatalyst could be described by Langmuir-Hinshelwood first-order kinetic model.

Kinetics of lead ion biosorption from aqueous solution onto lyophilized Aspergillus niveus

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Hülya Karaca ◽  
Turgay Tay ◽  
Merih Kıvanç
Keyword(s):  
Adsorption Capacity ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Lead Ions ◽  
Lead Ion ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Aspergillus Niveus ◽  
Pseudo Second Order

The biosorption of lead ions (Pb2+) onto lyophilized fungus Aspergillus niveus was investigated in aqueous solutions in a batch system with respect to pH, contact time and initial concentration of the ions at 30 °C. The maximum adsorption capacity of lyophilized A. niveus was found to be 92.6 mg g−1 at pH 5.1 and the biosorption equilibrium was established about in 30 min. The adsorption capacity obtained is one of the highest value among those reported in the literature. The kinetic data were analyzed using the pseudo-first-order kinetic, pseudo-second-order kinetic, and intraparticle diffusion equations. Kinetic parameters, such as rate constants, equilibrium adsorption capacities, and related correlation coefficients for the kinetic models were calculated and discussed. It was found that the adsorption of lead ions onto lyophilized A. niveus biomass fit the pseudo-second-order kinetic model well. The Langmuir and Freundlich isotherm parameters for the lead ion adsorption were applied and the Langmuir model agreed better with the adsorption of lead ions onto lyophilized A. niveus.

Nanoparticle Fe3O4 magnetized activated carbon from Armeniaca sibirica shell for the adsorption of Hg(II) ions

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6100-6120
Author(s):  
Yinan Hao ◽  
Yanfei Pan ◽  
Qingwei Du ◽  
Xudong Li ◽  
Ximing Wang
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Initial Concentration

Armeniaca sibirica shell activated carbon (ASSAC) magnetized by nanoparticle Fe3O4 prepared from Armeniaca sibirica shell was investigated to determine its adsorption for Hg2+ from wastewater. Fe3O4/ASSAC was characterized using XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), and BET (Brunauer–Emmett–Teller). Optimum adsorption parameters were determined based on the initial concentration of Hg2+, reaction time, reaction temperature, and pH value in adsorption studies. The experiment results demonstrated that the specific surface area of ASSAC decreased after magnetization; however the adsorption capacity and removal rate of Hg2+ increased 0.656 mg/g and 0.630%, respectively. When the initial concentration of Hg2+ solution was 250 mg/L and the pH value was 2, the adsorption time was 180 min and the temperature was 30 °C, and with the Fe3O4/ASSAC at 0.05 g, the adsorption reaching 97.1 mg/g, and the removal efficiency was 99.6%. The adsorption capacity of Fe3O4/ASSAC to Hg2+ was in accord with Freundlich isotherm models, and a pseudo-second-order kinetic equation was used to fit the adsorption best. The Gibbs free energy ΔGo < 0，enthalpy change ΔHo < 0, and entropy change ΔSo < 0 which manifested the adsorption was a spontaneous and exothermic process.

scholarly journals Removal of Chromium(VI) by Chitosan Beads Modified with Sodium Dodecyl Sulfate (SDS)

2020 ◽  
Vol 10 (14) ◽  
pp. 4745
Author(s):  
Xiaoyu Du ◽  
Chihiro Kishima ◽  
Haixin Zhang ◽  
Naoto Miyamoto ◽  
Naoki Kano
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Sodium Dodecyl ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Chitosan Beads ◽  
X Ray ◽  
Chromium Vi ◽  
Dodecyl Sulfate

In this study, chitosan beads modified with sodium dodecyl sulfate (SDS) were successfully synthesized and employed for the removal of chromium(VI) (Cr(VI)). The adsorption performance of the adsorbent (SDS-chitosan beads) was examined by batch experiments. The partition coefficient (PC) as well as the adsorption capacity were evaluated to assess the true performance of the adsorbent in this work. The adsorbent (SDS-chitosan beads) showed a maximum Cr(VI) adsorption capacity of 3.23 mg·g−1 and PC of 9.5 mg·g−1·mM−1 for Cr(VI). The prepared adsorbent was characterized by different techniques such as scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared spectroscopy (FT-IR). We used inductively coupled plasma mass spectrometry (ICP-MS) for the determination of Cr(VI) in solution. The experimental data could be well-fitted by pseudo-second-order kinetic and Langmuir isotherm models. The thermodynamic studies indicated that the adsorption process was favorable under the higher temperature condition. The SDS-modified chitosan beads synthesized in this work represent a promising adsorbent for removing Cr(VI).

scholarly journals Preparation of grafting copolymer of acrylic acid onto loess surface and its adsorption behavior

2020 ◽  
Vol 82 (4) ◽  
pp. 673-682
Author(s):  
Fengqin Tang ◽  
Di Gao ◽  
Li Wang ◽  
Yufeng He ◽  
Pengfei Song ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Adsorption Capacity ◽  
Removal Rate ◽  
Vinyl Pyrrolidone ◽  
Mineral Particle ◽  
Gravimetric Analysis ◽  
Order Kinetic ◽  
Experimental Conditions ◽  
Order Kinetic Model ◽  
Grafting Copolymer

Abstract Loess is a typical natural mineral particle distributed widely around the world, and it is inexpensive, readily accessible, and harmless to the environment. In this study, loess was modified by surface grafting copolymerization of functional monomers, such as acrylic acid, N-vinyl pyrrolidone, and N,N-methylenebisacrylamide as a cross-linking agent, which afforded a novel loess-based grafting copolymer (LC-PAVP). After being characterized by scanning electron microscopy, thermal gravimetric analysis and Fourier-transform infrared spectroscopy, its adsorption capacity and mechanism of removing lead ions (Pb2+) were investigated. With the study of the optimal experimental conditions, it was demonstrated that the removal rate of Pb2+ by LC-PAVP can reach up to 99.49% in 60 min at room temperature. It was also found that the kinetic characteristics of the adsorption capacity due to the pseudo-second-order kinetic model and the thermodynamics conformed well with the Freundlich model. In summary, as a lost-cost and eco-friendly loess-based adsorbent, LC-PAVP is a good potential material for wastewater treatment.

scholarly journals Adsorptive removal of phosphate by a Fe–Mn–La tri-metal composite sorbent: Adsorption capacity, influence factors, and mechanism

2020 ◽  
Vol 38 (7-8) ◽  
pp. 254-270
Author(s):  
Yuanrong Zhu ◽  
Xianming Yue ◽  
Fazhi Xie
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Phosphate Removal ◽  
Maximum Adsorption Capacity ◽  
Hydroxyl Groups ◽  
Metal Composite ◽  
Order Kinetic ◽  
Composite Sorbent ◽  
Composite Adsorbent

Reducing input of phosphorus is the key step for control of eutrophication and algal blooming in freshwater lakes. Adsorption technology is a cost-effective technology for phosphate removal in water for the purpose. Thus, in this study, a novel Fe–Mn–La tri-metal composite sorbent was developed, and then evaluated for phosphate removal. The results showed that the maximum adsorption capacity could be approached to 61.80 mg g−1 at 25°C under pH of 6.03. Adsorption of phosphate by Fe–Mn–La tri-metal composite adsorbent fitted better by pseudo-second-order kinetic equation and Langmuir model, which suggested that the adsorption process was surface chemical reactions and mainly in a monolayer coverage manner. The thermodynamic study indicated that the adsorption reaction was an endothermic process. The phosphate removal gradually decreased with the increasing of pH from 3.02 to 11.00. The sequence of coexisting anions competing with phosphates was that CO32− > Cl− > SO42− > NO3−. Dissolved organic matter, fulvic acid as a representative, would also decrease adsorption capacities of phosphate by Fe–Mn–La tri-metal composite adsorbents. Adsorption capacity would be decreased with increasing addition of adsorbents, while removal efficiency would be increased in this process. The Fe–Mn–La tri-metal composite adsorbent showed a good reusability when applied to removal of dissolved phosphate from aqueous solutions. The Fourier transform infrared spectrometer and X-ray photoelectron spectroscopy analyses indicated that some hydroxyl groups (–OH) on the surface of adsorbent were replaced by the adsorbed PO43−, HPO42−, or H2PO4−. Aggregative results showed that the novel Fe–Mn–La tri-mental composite sorbent is a very promising adsorbent for the removal of phosphate from aqueous solutions.

scholarly journals Synthesis of Copper and Lead ion Imprinted Polymer Submicron Spheres to Remove Cu2+ and Pb2+

2021 ◽  
Author(s):  
Yang Jiang ◽  
Bolin Tang ◽  
Pengfei Zhao ◽  
Man Xi ◽  
Yi Li
Keyword(s):  
Adsorption Capacity ◽  
Crosslinking Agent ◽  
Lead Ion ◽  
Maximum Adsorption Capacity ◽  
Ratio Analysis ◽  
Imprinted Polymer ◽  
Functional Monomers ◽  
Imprinted Polymers ◽  
Ion Imprinted ◽  
Bet Analysis

Abstract In this paper, methacrylic acid (MAA) and 4- vinyl pyridine (4-VP) as functional monomers, ethylene glycol two methyl acrylate (EGDMA) as crosslinking agent, isopropyl alcohol as the solvent, prepared the Cu(II)- and Pb(II)- imprinted polymers(IIPs) submicron spheres by precipitation polymerization. The presence/absence of the template ion in the preparation of the imprinted polymer was confirmed by EDX spectroscopy, and the structure of the particles was investigated using IR, SEM and BET analysis. From different components of crosslinker/monomer(C/M) ratio analysis, C/M at 1:3 was the optimal ratio for preparing IIPs. Atomic absorption spectroscopy (AAS) was characterized the imprinted polymers absorption behavior. The results show that the maximum adsorption capacity of Cu2+ and Pb2+ -imprinted polymer were 26.9mg﹒g−1 and 25.3mg﹒g−1, respectively. They also have good adsorption capacity and superior selectivity property for Cu2+ and Pb2+ in water, respectively. The selectivity factors (α) for Ni2+, Zn2+, Co2+ and Fe2+ were 16.5(Cu2+) and 12.1(Pb2+), 13.8(Cu2+) and 16.2(Pb2+), 10.8(Cu2+) and 10.1(Pb2+), 20.4(Cu2+) and 20.7(Pb2+), respectively. The regeneration experiment result demonstrates an excellent re-utilization property of these two type IIPs, after ten uses, the adsorption capacity can maintain above 60%.

Synthesis and Characterization of Zeolite X Obtained from Coal Gangue for Adsorption of Cu2+

2021 ◽  
Vol 13 (8) ◽  
pp. 1512-1520
Author(s):  
MiaoSen Zhang ◽  
SiYang Wang ◽  
Zheng Hu ◽  
RunZe Zhang ◽  
XiaoLi Wang
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Kinetics ◽  
Ph Value ◽  
Copper Ions ◽  
Removal Rate ◽  
Coal Gangue ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Zeolite X ◽  
Initial Ph

China is a big coal producing country, there are a lot of coal gangue piled up. The zeolite X was synthesized by alkali melting and hydrothermal method based on the coal gangue from Chifeng city, Inner Mongolia. The obtained zeolite X sample is characterized by X-ray diffraction, SEM, EDS spectrum and IR which showed the X zeolite is an octahedral structure with complete crystal shape and uniform grain size. The results of BET showed the specific surface area of zeolite X is 354.8 m2/g and the minimum pore size is 3.8 nm which indicated that the zeolite X belongs to mesoporous materials. The adsorption conditions of the zeolite X adsorbent on copper ions were optimized. A solution containing Cu2+ ions with an initial concentration of 300 mg/L was added to the zeolite X with a dosage of 0.1 g and the initial pH value of the solution was adjusted to 6. Then the solution was oscillated for 120 min at 225 r/min. The maximum adsorption capacity and removal rate were 148.6 mg/g and 99.1%, respectively. The adsorption mechanism was discussed by adsorption kinetics and thermodynamics. The quasi-second order kinetic equation can be well used to describe the adsorption kinetics of zeolite X to Cu2+ (R2 = 0.9994) and Langmuir can well describe the adsorption behavior of zeolite X to Cu2+ (R2 = 0.9995) which showed the adsorption is a monolayer of chemical adsorption. The adsorption capacity of zeolite X to Cu2+ is about 4.0 times that of coal gangue, indicating that the zeolite X has good adsorption capacity.

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