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 Hydrated Calcium Silicate Gel and its Adsorption Properties for Cu(II)

2020 ◽  
Vol 993 ◽  
pp. 1445-1449
Author(s):  
Shi Jie Liu ◽  
Su Ping Cui ◽  
Hong Xia Guo ◽  
Ya Li Wang ◽  
Nan Li ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Adsorption Method ◽  
Hydrated Calcium Silicate ◽  
Adsorption Performance ◽  
Optimum Reaction

Calcium silicate hydrate gel (CSH) was synthesized by calcium acetate and sodium silicate. The structure and morphology of CSH were characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy and Scanning electron microscopy. The adsorption performance of CSH was measured by static adsorption method. The results show that CSH has porous structure and large specific surface area, and the optimum reaction conditions is the reaction temperature of 25°C and calcium-silicon ratio of 1.2. It has the maximum adsorption capacity of more than 150 mg/g and the removal rate of more than 86% with Cu2+. And it shows the excellent adsorption performance, even when the concentration of Cu2+ is less than 200mg/L, the removal rate is above 90%. The research may provide a low-cost and high-efficiency adsorbent.

scholarly journals Facile preparation and highly efficient sorption of magnetic composite graphene oxide/Fe3O4/GC for uranium removal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aili Yang ◽  
Zhijun Wang ◽  
Yukuan Zhu
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Hydrothermal Carbonization ◽  
Maximum Adsorption Capacity ◽  
Magnetic Composite ◽  
Order Kinetic

AbstractIn this work, we reported for the first time a novel magnetic composite graphene oxide/Fe3O4/glucose-COOH (GO/Fe3O4/GC) that was facilely prepared from glucose through the hydrothermal carbonization and further combination with graphene oxide (GO). The chemical and structural properties of the samples were investigated. By the batch uranium adsorption experiments, the magnetic composite GO/Fe3O4/GC exhibits an excellent adsorption performance and fast solid–liquid separation for uranium from aqueous solution. GO/Fe3O4/GC (the maximum adsorption capacity (Qm) was 390.70 mg g−1) exhibited excellent adsorption capacity and higher removal rate (> 99%) for U(VI) than those of glucose-COOH (GC) and magnetic GC (MGC). The effect of the coexisting ions, such as Na+, K+, Mg2+, Ca2+, and Al3+, on the U(VI) removal efficiency of GO/Fe3O4/GC was examined. The equilibrium sorption and sorption rate for the as-prepared adsorbents well fit the Langmuir model and pseudo second-order kinetic model, respectively. The thermodynamic parameters (ΔH0 = 11.57 kJ mol−1 and ΔG0 < 0) for GO/Fe3O4/GC indicate that the sorption process of U(VI) was exothermic and spontaneous. Thus, this research provides a facile strategy for the preparation of the magnetic composite with low cost, high efficiency and fast separation for the U(VI) removal from aqueous solution.

scholarly journals Facile Preparation and Highly Efficient Sorption of Magnetic Composite Graphene Oxide/Fe3O4/GC for Uranium Removal

2021 ◽  
Author(s):  
Aili Yang ◽  
Zhijun Wang ◽  
Yukuan Zhu
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Hydrothermal Carbonization ◽  
Maximum Adsorption Capacity ◽  
Magnetic Composite ◽  
Order Kinetic

Abstract In this work, we reported for the first time a novel magnetic composite graphene oxide/Fe3O4/glucose-COOH (GO/Fe3O4/GC) that was facilely prepared from glucose through the hydrothermal carbonization and further combination with graphene oxide (GO). The chemical and structural properties of the samples were investigated. By the batch uranium adsorption experiments, the magnetic composite GO/Fe3O4/GC exhibits an excellent adsorption performance and fast solid-liquid separation for uranium from aqueous solution. GO/Fe3O4/GC (the maximum adsorption capacity (Qm) was 390.70 mg g-1) exhibited excellent adsorption capacity and higher removal rate (> 99%) for U(VI) than those of glucose-COOH (GC) and magnetic GC (MGC). The effect of the coexisting ions, such as Na+, K+, Mg2+, Ca2+, and Al3+, on the U(VI) removal efficiency of GO/Fe3O4/GC was examined. The equilibrium sorption and sorption rate for the as-prepared adsorbents well fit the Langmuir model and pseudo second-order kinetic model, respectively. The thermodynamic parameters (ΔH0 = 11.57 kJ mol-1 and ΔG0 < 0) for GO/Fe3O4/GC indicate that the sorption process of U(VI) was exothermic and spontaneous. Thus, this research provides a facile strategy for the preparation of the magnetic composite with low cost, high efficiency and fast separation for the U(VI) removal from aqueous solution.

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 Environmentally Friendly Gelatin/β-Cyclodextrin Composite Fiber Adsorbents for the Efficient Removal of Dyes from Wastewater

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2473 ◽  
Author(s):  
Yu Chen ◽  
Yanli Ma ◽  
Weipeng Lu ◽  
Yanchuan Guo ◽  
Yi Zhu ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
High Efficiency ◽  
Removal Rate ◽  
Gentian Violet ◽  
Low Cost ◽  
Environmentally Friendly ◽  
Composite Fiber ◽  
Raw Material ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic

In this paper, environmentally friendly gelatin/β-cyclodextrin (β-CD) composite fiber adsorbents prepared by electrospinning were used for the removal of dyes from wastewater. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and a universal materials tester were employed to characterize the internal structures, surface morphologies and mechanical strength of the composite fiber adsorbents. Additionally, the fiber was evaluated as an adsorbent for the removal of methylene blue (MB) from aqueous solution. The effects of the raw material ratio, pH, temperature, concentration and adsorption time were studied. The results show that the gelatin/β-CD composite fiber adsorbents possess excellent mechanical strength and high adsorption efficiency for MB. The adsorption equilibrium and adsorption kinetics are well-described by the Langmuir isotherm model and the pseudo-second-order kinetic model, respectively. The theoretical maximum adsorption capacity is 47.4 mg·g−1. Additionally, after nine successive desorption-adsorption cycles, the removal rate is still over 70%. Moreover, the gelatin/β-CD composite fiber adsorbents exhibit excellent adsorption capability for basic fuchsin, gentian violet, brilliant blue R and malachite green dyes. Therefore, owing to the characteristics of degradability, low cost and high-efficiency, the gelatin/β-CD composite fiber can be used as an efficient adsorbent for the removal of dyes from wastewater.

scholarly journals Chemical Modification of Combusted Coal Gangue for U(VI) Adsorption: Towards a Waste Control by Waste Strategy

2021 ◽  
Vol 13 (15) ◽  
pp. 8421
Author(s):  
Yuan Gao ◽  
Jiandong Huang ◽  
Meng Li ◽  
Zhongran Dai ◽  
Rongli Jiang ◽  
...  
Keyword(s):  
Structural Analysis ◽  
High Efficiency ◽  
Low Cost ◽  
Chemical Activation ◽  
Cost Effective ◽  
Coal Gangue ◽  
Order Kinetic ◽  
Practical Applications ◽  
Detailed Structural Analysis ◽  
Alkaline Conditions

Uranium mining waste causes serious radiation-related health and environmental problems. This has encouraged efforts toward U(VI) removal with low cost and high efficiency. Typical uranium adsorbents, such as polymers, geopolymers, zeolites, and MOFs, and their associated high costs limit their practical applications. In this regard, this work found that the natural combusted coal gangue (CCG) could be a potential precursor of cheap sorbents to eliminate U(VI). The removal efficiency was modulated by chemical activation under acid and alkaline conditions, obtaining HCG (CCG activated with HCl) and KCG (CCG activated with KOH), respectively. The detailed structural analysis uncovered that those natural mineral substances, including quartz and kaolinite, were the main components in CCG and HCG. One of the key findings was that kalsilite formed in KCG under a mild synthetic condition can conspicuous enhance the affinity towards U(VI). The best equilibrium adsorption capacity with KCG was observed to be 140 mg/g under pH 6 within 120 min, following a pseudo-second-order kinetic model. To understand the improved adsorption performance, an adsorption mechanism was proposed by evaluating the pH of uranyl solutions, adsorbent dosage, as well as contact time. Combining with the structural analysis, this revealed that the uranyl adsorption process was mainly governed by chemisorption. This study gave rise to a utilization approach for CCG to obtain cost-effective adsorbents and paved a novel way towards eliminating uranium by a waste control by waste strategy.

scholarly journals Preparation and Characterization of High-Efficiency Magnetic Heavy Metal Capture Flocculants

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1732
Author(s):  
Yuanyuan Yu ◽  
Yongjun Sun ◽  
Jun Zhou ◽  
Aowen Chen ◽  
Kinjal J. Shah
Keyword(s):  
Heavy Metal ◽  
Reaction Time ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Monomer Concentration ◽  
Synthesis Process ◽  
Response Surface Optimization ◽  
Metal Capture ◽  
Total Monomer Concentration

In this study, a high-efficiency magnetic heavy metal flocculant MF@AA was prepared based on carboxymethyl chitosan and magnetic Fe3O4. It was characterized by SEM, FTIR, XPS, XRD and VSM, and the Cu(II) removal rate was used as the evaluation basis for the preparation process. The effects of AMPS content, total monomer concentration, photoinitiator concentration and reaction time on the performance of MF@AA flocculation to remove Cu(II) were studied. The characterization results show that MF@AA has been successfully prepared and exhibits good magnetic induction characteristics. The synthesis results show that under the conditions of 10% AMPS content, 35% total monomer concentration, 0.04% photoinitiator concentration, and 1.5 h reaction time, the best yield of MF@AA is 77.69%. The best removal rate is 87.65%. In addition, the response surface optimization of the synthesis process of MF@AA was performed. The optimal synthesis ratio was finally determined as iron content 6.5%, CMFS: 29.5%, AM: 53.9%, AMPS: 10.1%. High-efficiency magnetic heavy metal flocculant MF@AA shows excellent flocculation performance in removing Cu(II). This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove Cu(II) in wastewater.

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.

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