scholarly journals A Review of Adsorbents for Heavy Metal Decontamination: Growing Approach to Wastewater Treatment

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4702
Author(s):  
Archana Gupta ◽  
Vishal Sharma ◽  
Kashma Sharma ◽  
Vijay Kumar ◽  
Sonal Choudhary ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Physical Adsorption ◽  
Treatment Strategies ◽  
Freundlich Isotherm ◽  
Sorption Kinetics ◽  
Contamination Level ◽  
Adsorption Mechanisms ◽  
Solute Uptake ◽  
Pseudo Second Order ◽  
Recommended Level

Heavy metal is released from many industries into water. Before the industrial wastewater is discharged, the contamination level should be reduced to meet the recommended level as prescribed by the local laws of a country. They may be poisonous or cancerous in origin. Their presence does not only damage people, but also animals and vegetation because of their mobility, toxicity, and non-biodegradability into aquatic ecosystems. The review comprehensively discusses the progress made by various adsorbents such as natural materials, synthetic, agricultural, biopolymers, and commercial for extraction of the metal ions such as Ni2+, Cu2+, Pb2+, Cd2+, As2+ and Zn2+ along with their adsorption mechanisms. The adsorption isotherm indicates the relation between the amount adsorbed by the adsorbent and the concentration. The Freundlich isotherm explains the effective physical adsorption of the solute particle from the solution on the adsorbent and Langmuir isotherm gives an idea about the effect of various factors on the adsorption process. The adsorption kinetics data provide valuable insights into the reaction pathways, the mechanism of the sorption reaction, and solute uptake. The pseudo-first-order and pseudo-second-order models were applied to describe the sorption kinetics. The presented information can be used for the development of bio-based water treatment strategies.

scholarly journals Equilibrium and Kinetic Study of Anionic and Cationic Pollutants Remediation by Limestone–Chitosan–Alginate Nanocomposite from Aqueous Solution

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2586
Author(s):  
Inas A. Ahmed ◽  
Ahmed H. Ragab ◽  
Mohamed A. Habila ◽  
Taghrid S. Alomar ◽  
Enas H. Aljuhani
Keyword(s):  
Physical Adsorption ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Sem Images ◽  
Bet Analysis ◽  
Adsorption Processes ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Multilayer Formation

In this work, low-cost and readily available limestone was converted into nanolimestone chitosan and mixed with alginate powder and precipitate to form a triple nanocomposite, namely limestone—chitosan–alginate (NLS/Cs/Alg.), which was used as an adsorbent for the removal of brilliant green (BG) and Congo red (CR) dyes in aqueous solutions. The adsorption studies were conducted under varying parameters, including contact time, temperature, concentration, and pH. The NLS/Cs/Alg. was characterized by SEM, FTIR, BET, and TEM techniques. The SEM images revealed that the NLS/Cs/Alg. surface structure had interconnected pores, which could easily trap the pollutants. The BET analysis established the surface area to be 20.45 m2/g. The recorded maximum experimental adsorption capacities were 2250 and 2020 mg/g for CR and BG, respectively. The adsorption processes had a good fit to the kinetic pseudo second order, which suggests that the removal mechanism was controlled by physical adsorption. The CR and BG equilibrium data had a good fit for the Freundlich isotherm, suggesting that adsorption processes occurred on the heterogeneous surface with a multilayer formation on the NLS/Cs/Alg. at equilibrium. The enthalpy change (ΔH0) was 37.7 KJ mol−1 for CR and 8.71 KJ mol−1 for BG, while the entropy change (ΔS0) was 89.1 J K−1 mol−1 for CR and 79.1 J K−1 mol−1 BG, indicating that the adsorption process was endothermic and spontaneous in nature.

scholarly journals 1,2,3,4-Tetrahydropyrimidine Derivative for Selective and Fast Uptake of Cadmium Ions from Aqueous Solution

Environments ◽  
2019 ◽  
Vol 6 (6) ◽  
pp. 68
Author(s):  
Mohamed Ould M’hamed ◽  
Lotfi Khezami
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Kinetics ◽  
Heavy Metal Ions ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Solution Interface ◽  
Adsorption Data ◽  
Pseudo Second Order ◽  
Thermodynamic Variables

The aim of this work was to evaluate the performance of a 1,2,3,4-tetrahydropyrimidine derivative as a powerful heterocyclic compound for the elimination of Cd(II) ions from aqueous solutions. The tetrahydropyrimidine derivative was prepared during 30 min of milling by planetary ball mill with a ball-to-powder mass ratio of 8:1 and a rotation speed of 750 rpm. Nuclear magnetic resonance (NMR) and infrared (IR) were used to identify the obtained tetrahydropyrimidine derivatives. Furthermore, batches of experiments were carried out to establish the adsorption equilibrium, kinetics, and thermodynamic variables of the tetrahydropyrimidine derivatives for toxic heavy Cd(II) ions. The adsorption data were simulated by applying the Langmuir manner, the Freundlich equation, the pseudo-first-order and pseudo-second-order equations. The adsorption procedure was discovered to be very influenced by PH. The removal of heavy metal ions reached a maximum value quickly within 6 min and the adsorption data better adjusted the Langmuir isotherm than that of the Freundlich isotherm. The maximum Cd(II) ions adsorption capacity was approximated to be 151.16 mg g−1 at 328 K and a pH of 6 to 7. It was found that the adsorption kinetics of Cd(II) ions obeyed pseudo-second-order adsorption kinetics. The examination of the thermodynamic variables of tetrahydropyrimidine derivative showed a spontaneous endothermic adsorption procedure. Otherwise, positive entropy values put forward a rise in the randomness at the solid-solution interface when heavy metal ions are adsorbed.

Removal of Heavy Metal from Wastewater Using Zeolite from Fly Ash

2012 ◽  
Vol 518-523 ◽  
pp. 2736-2739 ◽  
Author(s):  
Chang Nian Wu ◽  
Yu Chao Tang ◽  
Li Hua Tang
Keyword(s):  
Heavy Metal ◽  
Fly Ash ◽  
Heavy Metal Ions ◽  
Coal Fly Ash ◽  
Freundlich Isotherm ◽  
Zeolite Synthesis ◽  
Pseudo Second Order ◽  
Xrd Patterns ◽  
Isotherm Equations ◽  
Modified Forms

Coal fly ash (CFA) was modified by hydrothermal treatment using NaOH solutions for zeolite synthesis. The XRD patterns of zeolite and coal fly ash are presented. The synthesized zeolite was investigated for adsorption of heavy metal ions in aqueous solution. It was shown that fly ash and the modified forms could effectively absorb heavy metals. The adsorption isotherm could be described by Freundlich isotherm equations. The pseudo second-order kinetics would be better for fitting the dynamic adsorption of Cu2+ and Cd2+.

scholarly journals Hydrazinolyzed cellulose-g-polymethyl acrylate as adsorbent for efficient removal of Cd(II) and Pb(II) ions from aqueous solution

2016 ◽  
Vol 75 (5) ◽  
pp. 1051-1058 ◽  
Author(s):  
Qiujin Jia ◽  
Wanting Zhang ◽  
Dongping Li ◽  
Yulong Liu ◽  
Yuju Che ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Physical Adsorption ◽  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Initial Ph ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Efficient Adsorbent

Hydrazinolyzed cellulose-graft-polymethyl acrylate (Cell-g-PMA-HZ), an efficient adsorbent for removal of Cd(II) and Pb(II) from aqueous solution, has been prepared by ceric salt-initiated graft polymerization of methyl acrylate from microcrystalline cellulose surface and subsequent hydrazinolysis. The influences of initial pH, contact time, and temperature on adsorption capacity of Cell-g-PMA-HZ as well as adsorption equilibrium, kinetic and thermodynamic properties were examined in detail. As for Cd(II) adsorption, kinetic adsorption can be explained by pseudo-second-order, while adsorption isotherm fits well with Langmuir isotherm model, from which maximum equilibrium adsorption capacity can be derived as 235.85 mg g−1 at 28 °C. Further thermodynamic investigation indicated that adsorption of Cd(II) by adsorbent Cell-g-PMA-HZ is endothermic and spontaneous under studied conditions. On the other hand, isotherm of Pb(II) adsorption fits well with Freundlich isotherm model and is more likely to be a physical-adsorption-dominated process. Consecutive adsorption–desorption experiments showed that Cell-g-PMA-HZ is reusable with satisfactory adsorption capacity.

scholarly journals Enhanced Removal of Sulfonated Lignite from Oil Wastewater with Multidimensional MgAl-LDH Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 861
Author(s):  
Ling Zhou ◽  
Michal Slaný ◽  
Bingbing Bai ◽  
Weichao Du ◽  
Chengtun Qu ◽  
...  
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Adsorption Process ◽  
Freundlich Isotherm ◽  
Hydrothermal Condition ◽  
Adsorption Mechanisms ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Double Hydroxide ◽  
Oil Wastewater ◽  
Layered Double Hydroxide Nanoparticles

In this study, hierarchical MgAl-LDH (layered double hydroxide) nanoparticles with a flower-like morphology were prepared under a hydrothermal condition by employing worm-like micelles formed by cetyltrimethylammonium bromide (CTAB) and salicylic acid (SA) as templates. The morphology and structure of the materials were characterized by Brunauer–Emmett–Teller (BET), SEM, and XRD analyses. The performance for the adsorption of sulfonated lignite (SL) was also investigated in detail. FTIR was used to detect the presence of active functional groups and determine whether they play important roles in adsorption. The results showed that the hierarchical MgAl-LDH nanoparticles with a specific surface area of 126.31 m2/g possessed a flower-like morphology and meso–macroporous structures. The adsorption capacity was high—its value was 1014.20 mg/g at a temperature of 298 K and an initial pH = 7, which was higher than traditional MgAl-LDH (86 mg/g). The adsorption process of sulfonated lignite followed the pseudo-second-order kinetics model and conformed to Freundlich isotherm model with a spontaneous exothermic nature. In addition, the hierarchical MgAl-LDH could be regenerated and used, and the adsorption was high after three adsorption cycles. The main adsorption mechanisms were electrostatic attraction and ion exchange between the hierarchical MgAl-LDH and sulfonated lignite.

scholarly journals Mechanistic Insight of Biochar-layered Double Hydroxide Composite for Efficient Removal of Aqueous Pb(II) and Cu(II)

2021 ◽  
Author(s):  
Xinyue Su ◽  
Yan Chen ◽  
Yanfei Li ◽  
Jing Li ◽  
Wen Song ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Layered Double Hydroxide ◽  
Adsorption Process ◽  
Efficient Removal ◽  
Mineral Precipitation ◽  
Adsorption Mechanisms ◽  
Mechanistic Insight ◽  
Heavy Metal Wastewater ◽  
Pseudo Second Order ◽  
Double Hydroxide

Abstract To explore the heavy metal adsorption mechanisms by biochar-based materials, MgAl-layered double hydroxide (MgAl-LDH) was loaded on a commercial coconut shell biochar (BC) to obtain the composite (BC-LDH) for adsorptive decontamination of Pb(II) and Cu(II) in water. The removal capacities of BC-LDH (294 and 38.6 mg/g) was higher than BC (13.3 and 11.4 mg/g) and LDH (126 and 22.7 mg/g) for aqueous Pb(II) and Cu(II). The pseudo-second-order equation and the Langmuir model could better illustrate the adsorption process, respectively. The interaction mechanisms between BC-LDH and heavy metals were classified as mineral precipitation (Qpre), cation exchange and isomorphic replacement (Qexc), electrostatic attraction (Qele), and surface complexation (Qcom) according to the characterization results. The quantitative analysis indicated that the contributions of the above mechanisms of BC-LDH for Pb(II) and Cu(II) followed the order of Qpre > Qele > Qexc and Qpre > Qexc > Qele, respectively. Compared with BC, the Qpre increased and Qele decreased significantly, certified the combination of BC and LDH provided a kind of viable composite in heavy metal wastewater treatment.

scholarly journals Mechanisms of Adsorption of Heavy Metal Cations from Waters by an Amino Bio-Based Resin Derived from Rosin

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 969 ◽  
Author(s):  
Wanting Huang ◽  
Kaisheng Diao ◽  
Xuecai Tan ◽  
Fuhou Lei ◽  
Jianxin Jiang ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Critical Role ◽  
Freundlich Isotherm ◽  
Exchange Capacity ◽  
Natural Material ◽  
Multicomponent Systems ◽  
Adsorption Mechanisms ◽  
Heavy Metal Cations ◽  
13C Nuclear Magnetic Resonance ◽  
Routine Removal

Rosin derived from conifer trees is used as the basis for a novel environmentally-friendly adsorbent prepared from a sustainable resource. After treatment with ethylenediamine, ethylenediamine rosin-based resin (EDAR) is produced, which possesses cation exchange capacity that is comparable to that of the best commercial synthetic resins. This is demonstrated by its application to the removal of Pb, Cd, and Cu from water, in single and multicomponent systems. Maximum uptake was obtained at pH 5 and in the order Pb(II) > Cd(II) > Cu(II). The maximum adsorption of Pb was ~1.8 mmol/g, but the adsorption process resembled the Freundlich isotherm, whereas the adsorption of Cd(II) and Cu(II) followed the Langmuir isotherm. In the multicomponent systems, there was direct competition between Pb and Cd for sorption sites, whereas the results with Cu indicated it had a preference for different types of sites compared to Pb and Cd. The EDAR resin could be efficiently regenerated and used repeatedly with only a small decrease in performance. Characterization of EDAR, and investigations of its adsorption mechanisms using physical, spectroscopic, and theoretical techniques, including fourier transform infrared spectroscopy (FTIR), 13C nuclear magnetic resonance (13C NMR), scanning electron microscope (SEM), Brunauer Emmett Teller (BET) method, elemental analysis, thermogravimetric analysis (TGA), and molecular dynamics calculations, showed that amino groups have a critical role in determining the cation adsorption properties. We conclude that this new adsorbent derived from an abundant natural material has the potential to make valuable contributions to the routine removal of heavy metal ions (HMs) from drinking water and wastewater.

scholarly journals Removal of methylene blue from aqueous solution using sediment obtained from a canal in an industrial park

2018 ◽  
Vol 78 (3) ◽  
pp. 556-570 ◽  
Author(s):  
Lih-Fu Chen ◽  
Hsiou-Hsuan Wang ◽  
Kao-Yung Lin ◽  
Jui-Yen Kuo ◽  
Ming-Kuang Wang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Physical Adsorption ◽  
Sorption Isotherms ◽  
Freundlich Isotherm ◽  
Industrial Park ◽  
Pseudo Second Order ◽  
Ir Analysis ◽  
Increasing Temperature ◽  
Kinetics Of ◽  
Mb Adsorption

Abstract Drainage canal sediments in an industrial park are generally dredged to landfill in Taiwan. The objective of this study was to evaluate feasibility employing the sediment as an adsorbent for removal of dye. The sediment contained approximately 10% of organic matter and little heavy metals. Infrared (IR) analysis revealed that carboxyl was the most important functional group for methylene blue (MB) sorption. Canal sediment could remove the most MB from water at pH 8.0 and this removal increased with increasing temperature. The MB sorption was well described by the Langmuir, Dubinin–Radushkevich, and Temkin sorption isotherms at 10°C, but it showed good compliance with Freundlich isotherm at 25°C and 40°C. The MB adsorption was a spontaneous and endothermic reaction; its maximum calculated adsorption capacity (Qm) was 56.0 mg g−1 at 10°C by the Langmuir isotherm. The calculated values of enthalpy (ΔH°) and entropy (ΔS°) are 14.6 kJ mol−1 and 149.2 kJ mol−1, respectively. Only pseudo-second-order adsorption kinetic model successfully described the kinetics of MB onto the sediment at different operation parameters. Activation energy of MB adsorption calculated from Arrhenius equation was 16.434 kJ mol−1, indicating the binding between canal sediment and MB was a physical adsorption.

scholarly journals Preparation of Calixarene-PI Nanofibers and Application as a Selective Adsorbent for Heavy Metal Ions

2018 ◽  
Vol 13 (1) ◽  
pp. 155892501801300
Author(s):  
Xuchen Tao ◽  
Quan Feng ◽  
Hui He
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Kinetics ◽  
Heavy Metal Ions ◽  
Selective Adsorption ◽  
Physical Adsorption ◽  
Second Order ◽  
Kinetics Model ◽  
Isothermal Model ◽  
Pseudo Second Order

In order to utilize the adsorption selectivity of calixarenes towards heavy metal ions, calixarene functionalized polyimide (Calix-PI) fibers were prepared by three main synthesis procedures including preparation of the calixarene polyamide acid (Calix-PAA) spinning solution via amidation, fabrication of the Calix-PAA fibers by electrospinning, and preparation of the Calix-PI fibers via thermal imidization on the Calix-PAA fibers. The Calix-PI fibers were characterized by Fourier transform infrared spectroscopy, scanning electronic microscopy and thermogravimetric analysis. The Calix-PI fibers display selective adsorption on Pb(II), which is fit with the pseudo-second-order adsorption kinetics model and the Freundlich adsorption isothermal model. The rate constant of the pseudo-second-order adsorption kinetics model and the maximum Pb(II) uptake have all been calculated. The practical adsorption of Pb(II) on the Calix-PI fibers is mainly attributed to the monolayer chemical adsorption and slightly depended on the physical adsorption.

scholarly journals Adsorption of benzalkonium chlorides onto powdered activated carbon: mechanisms and detoxification

2021 ◽  
Vol 27 (6) ◽  
pp. 210496-0
Author(s):  
Tae-Kyoung Kim ◽  
Woo-Seok Choe ◽  
Taeyeon Kim ◽  
Seon-Ha Chae ◽  
Yu Sik Hwang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Freundlich Isotherm ◽  
Powdered Activated Carbon ◽  
Adsorption Mechanisms ◽  
Alkyl Chains ◽  
Global Demand ◽  
Endothermic Process ◽  
Pseudo Second Order ◽  
Microtox Test ◽  
Kinetics Of

Because disinfectants have been essential during the COVID-19 pandemic, the global demand for benzalkonium chlorides (BACs) has significantly increased. BACs can inactivate coronaviruses, but are known as toxic. In this study, we investigated the adsorption mechanisms of BAC12, BAC14, and BAC16 in water using powdered activated carbon (PAC). The effects of the reaction time, pH, and temperature on the adsorption kinetics of BACs were examined. The adsorption reaction followed pseudo-second-order kinetics, and better fitted to the Langmuir isotherm than the Freundlich isotherm. The best adsorption of BACs was achieved at neutral pH conditions. Thermodynamic analysis revealed that adsorption of BACs onto PAC is a spontaneous and endothermic process. Competitive adsorption experiments revealed that BACs with longer alkyl chains were adsorbed more effectively onto PAC than shorter alkyl chain BACs, implying that, while the electrostatic interaction is an important adsorption mechanism for BAC12, van der Waals interaction plays a more important role during the adsorption of BAC14 and BAC16. Finally, we observed the partial detoxification (69%) BAC in adsorption treated water with PAC using a Microtox test.

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