Preparation Of Adsorbents Research Articles

Preparation of new CaFeAl-layered doubled hydroxides adsorbent for Cr(VI) adsorption from polyaluminum chloride residue

Preparation of new CaFeAl-layered doubled hydroxides adsorbent for Cr(VI) adsorption from polyaluminum chloride residue

Role of nanohybrid NiO–Fe3O4 in enhancing the adsorptive performance of activated carbon synthesized from Yemeni-Khat leave in removal of Pb (II) and Hg (II) from aquatic systems

Over years, existence of toxic chemical heavy metal in aquatic systems has motivated more research studies toward the preparation of effective stable solid adsorbents for the removal of toxic chemical pollutants. Therefore, in the current research study, activated carbon adsorbent (AC) was synthesized from Yemeni khat (catha edulis) leaves which are considered as waste accumulated on waste disposal areas in Yemen. KOH (2.0 N) was used as a chemical activator to produce the AC material which was subsequently heated at 400 °C. A simple co-precipitation method was used to chemically modify AC with varying weight ratios of NiO–Fe3O4 NPs (5, 15, and 25 wt %). The modified AC was used to remove toxic Pb(II) and Hg(II) ions from aquatic systems. Numerous techniques, which included x-ray diffraction (XRD), Fourier transforms infrared (FTIR), field emission scanning electron microscope (FE-SEM), and N2 adsorption/desorption isotherms, were used to confirm the morphology of AC and 5, 15, and 25 wt% NiO–Fe3O4/AC samples. The study findings demonstrated that, NiO–Fe3O4 nanoparticles improved the adsorption efficiency for toxic Pb(II) and Hg (II) ions. The AC adsorbent attained maximum removal efficiencies of 88.95% and 87.56% for Pb (II) and Hg (II) ions, respectively. In contrast, 15-NF/AC NC sample successfully attained the highest removal efficiencies of 100% for pb(II) and 99.71% for Hg(II). According to the experimental findings, the prepared NF/AC adsorbents were effective and they can be used as inexpensive and stable solid nanoadsorbents in water treatment.

Sedimentable polyethyleneimine-modified yeast residue enhances the selective adsorption of Pd(II) by altering isoelectric point

Modifying the surface of microorganisms is a common method for increasing microbial adsorption capacity although further treatment of the microorganisms is required to facilitate the use. However, only a few studies have explored how to simultaneously achieve selective adsorption ability and convenient separation. In this paper, the maximum Pd(II) adsorption capacity on polyethyleneimine (PEI)-modified Pichia pastoris residue (PEI-PR) was achieved at a PEI:glutaraldehyde (GA) ratio of 4:1. An adsorption kinetics study showed that PEI-modified biomass (PEI-PR) reached adsorption equilibrium within 180 min, and the adsorption conformed to the pseudo-second-order model. Using the Langmuir adsorption isotherm, the maximum adsorption capacity for Pd(II) at pH 3 was found to be 587.67 mg∙g−1 of dry weight. After five adsorption–desorption cycles, PEI-PR could maintain 90.35% of its initial adsorption capacity. Moreover, PEI-PR showed satisfactory selectivity to Pd(II) in simulated multi-metal solution. The selective adsorption efficiency of PEI-PR was mainly due to the introduction of a large number of amino and imino groups onto the surface of the biomass through PEI modification, which caused the increase of the isoelectric point from 4.64 to 9.46. At a pH value lower than its isoelectric point, PEI-PR became protonated and thus was positively charged. As a result, it could only undergo electrostatic adsorption with negatively charged Pd(II) chloride complex ions, rather than with other positively charged metal ions. The adsorption complex could be separated from the solution via sedimentation. This research presents a new approach for preparation of microbial adsorbent with selective adsorption capacity and can conveniently be separated from a solid–liquid mixture. It is a green approach for efficient microbial adsorption and recovery of Pd(II).

Bamboo-derived adsorbents for environmental remediation: A review of recent progress

The bamboo family of plants is one of the fastest-growing species in the world. As such, there is an abundance of bamboo residues available for exploitation, especially in southeast Asian, central African and south American regions. The preparation of efficient adsorbents from bamboo residues is an emerging exploitation pathway. Biochars, activated carbons or raw bamboo fibers embedded with nanoparticles, each class of materials has been shown to be highly efficient in adsorption processes. This review aims to summarize recent findings in the application of bamboo-based adsorbents in the removal of organic, inorganic, or gaseous pollutants. Therefore, this review first discusses the preparation methods and surface modification methodologies and their effects on the adsorbent elemental content and other basic properties. The following sections assess the recent progress in the adsorption of heavy metals, organics, and gaseous substances by bamboo-based adsorbents, focusing on the optimum adsorption capacities, adsorption mechanisms and the optimum-fitting kinetic models and isotherms. Finally, research gaps were identified and directions for future research are proposed.

High-efficiency removal of Cs (I) by vermiculite/zinc hexacyanoferrate (II) composite from aqueous solutions

Aimed to solve the problems of low adsorption capacity, complex preparation and difficult recovery for reported cesium ion adsorbents, a novel high-efficiency Cs+ adsorbent of vermiculite/zinc hexacyanoferrate (II) (VMT/ZnHCF) composite was prepared via in situ synthetic method. The structure and properties of this composite were comprehensively characterized using XRD, FTIR, SEM, TEM, and TG-DTA. The maximum Cs+ adsorption capacity was recorded to be 378.79 mg/g, and this value was significantly higher than the values recorded for other absorbents. This spontaneous and exothermic adsorption behavior could be explained by the Langmuir isotherm model and the pseudo-second-order kinetic model. In addition, this composite exhibited excellent selective adsorption ability towards Cs+ even in solutions containing high concentrations of Na+, K+, Ca2+, and Mg2+. The Cs+ adsorption mechanism was analyzed by conducting ion exchange experiments and using XRD, SEM, and XPS techniques. The Cs+ adsorption of the VMT/ZnHCF composite was synergistically achieved through the ion exchange of Na+ in vermiculite interlayers and Zn2+ in zinc hexacyanoferrate (II) lattices. A high-efficiency and simple preparation of cesium ion adsorbent has been developed in application of cesium ion wastewater treatment. This work can provide theoretical guidance to realize the non-hazardous treatment of radioactive wastewater.

Removal of methylene blue and safranin orange pollutants from liquid effluents by soy residue

AbstractMethylene blue and safranin orange dyes, which are used in the textile and pharmaceutical industries, can severely damage the environment and human health. This study investigated the use of okara residue as an alternative biosorbent for the removal of methylene blue and safranin orange dyes. Substantial amounts of okara residue are generated daily during the processing of soy milk in the agro‐industrial sector. Dye adsorption was not affected by pH. An adsorption study identified the optimal experimental conditions as: 298 K, 0.03 g of adsorbent in 30 mL of dye solution at a concentration of 50 mg L−1, and a contact time of 300 min for methylene blue dye, and 298 K, 0.02 g of adsorbent in 30 mL of dye solution at a concentration of 50 mg L−1, and a contact time of 200 min for safranin orange dye; the maximum adsorption capacities were 93.201 ± 0.01 and 184 592 ± 0.02 mg g−1, respectively. Okara has considerable advantages over other natural materials as an alternative for the treatment of industrial effluents. Because it is easily obtained and does not require any physicochemical treatment, adsorption does not require any specific operation temperature. In addition, okara exhibited a high adsorption capacity compared to other natural materials that require chemical and physical processing for adsorbent preparation.

Recovery of metallic oxide rich biochar from waste chicken feather

Over the years, the devastating impact of climate change has become pronounced due to inadequate regulation for waste disposal in a developing country like Nigeria. The chicken feather-based metal oxide-rich (MOR) biochar was produced using a top-lit updraft reactor at a peak temperature of 417.2 °C to give a yield of 28.19%. The results were analyzed using Brunauer-Emmett-Teller BET, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Energy Dispersive Spectroscopy (EDS), and X-ray fluorescence spectroscopy (XRF). The result shows that the sample is mesoporous (pore diameter of 2.132 nm) with a BET surface area of 105.7 m2/g. CaO (33.147 wt%) and SO3 (25.673 wt%) were the major oxides present in notable proportions on the material surface, which were evident in the SEM micrograph. The major elemental compositions of the raw sample were oxygen (36.917 wt%) and calcium (23.690 wt%), and the major minerals present were quartz, marialite, davyne, and graphite. The present study elucidates the successful and efficient material recovery route for the preparation of adsorbents and precursors for many product synthesis processes.Graphical

Role of magnetic substances in adsorption removal of ciprofloxacin by gamma ferric oxide and ferrites co-modified carbon nanotubes

Antibiotics have been considered an evolving environmental challenge in the last few decades due to their mutagenic and persistent effects. Herein, we synthesized γ-Fe2O3 and ferrites nanocomposites co-modified carbon nanotubes (γ-Fe2O3/MFe2O4/CNTs, M: Co, Cu, and Mn) with high crystallinity, thermostability, and magnetization for the adsorption removal of ciprofloxacin. The experimental equilibrium adsorption capacities of ciprofloxacin on γ-Fe2O3/MFe2O4/CNTs were 44.54 (Co), 41.13 (Cu), and 41.53 (Mn) mg/g, respectively. The adsorption behaviors followed the Langmuir isotherm and pseudo-first-order models. Density functional theory calculations revealed that the active sites preferentially appeared on the oxygen of the carboxyl group in ciprofloxacin, and the calculated adsorption energies of ciprofloxacin on CNTs, γ-Fe2O3, CoFe2O4, CuFe2O4, and MnFe2O4 were –4.82, –1.08, –2.49, –0.60, and 5.69 eV, respectively. The addition of γ-Fe2O3 changed the adsorption mechanism of ciprofloxacin on MFe2O4/CNTs and γ-Fe2O3/MFe2O4/CNTs. CNTs and CoFe2O4 controlled the cobalt system of γ-Fe2O3/CoFe2O4/CNTs, while CNTs and γ-Fe2O3 ruled the adsorption interaction and capacity of copper and manganese systems. This work reveals the role of magnetic substances, which is beneficial to the preparation and environmental application of similar adsorbents.

Preparation of a novel metal-free polypyrrole-red phosphorus adsorbent for efficient removal of Cr(VI) from aqueous solution

The toxicity and carcinogenicity of Cr(VI) makes it a major threat to the health of animals and people. However, how to efficiently remove Cr(VI) still faces important challenges. In this study, a new metal-free polypyrrole-red phosphorus (PPy-RP) composite is successfully synthesized by in-situ oxidation polymerization for Cr(VI) removal from wastewater. The maximum adsorption capacity (qm) of Cr(VI) on PPy-RP-1 is 513.2 mg/g when the pH value is 2, which is far superior to RP nanosheets (207.8 mg/g) and PPy (294.9 mg/g). The improved qm can be ascribe to the good dispersion and increased specific surface area of PPy-RP adsorbent. Encouragingly, PPy-RP adsorbent still exhibits excellent stability after 7 cycles tests without a significant decline in removal efficiency, and remain above 81.4%. Based on the fittings of adsorption isotherms and kinetics, the process conforms to the pseudo-first-order kinetic model and the single-layer adsorption of the Langmuir model with an R2 value of 0.98533. The adsorption process is chemical and monolayer. The experimental result demonstrates that the PPy-RP can efficient removal Cr(VI) by electrostatic attraction and complexation reaction (formation of N–Cr(VI) bond) through the PPy on the surface. The results of this study indicate that PPy-RP is a promising adsorbent to remove the Cr(IV).

Microporous melamine-formaldehyde networks loaded on rice husks for dynamic removal of organic micropollutants

The alteration of agricultural wastes into novel adsorbents can stimulate their scalability in realistic application, showing great economic and environmental advantages. Here, we proposed a strategy to engineer rice husk (RH) with microporous melamine-formaldehyde networks (MFNs) resins and the utilization for dynamic removal of organic micropollutants rapidly and efficiently. was pre-treated to acquire attractive surface and unique hierarchical porosity, endowing with surface functionalization and essential filtering properties. MFNs can be uniformly generated in-situ on the fully exposed cellulose backbones of the pre-treated RH. MFNs granules functionalized RH (RH@MFNs) exhibited high removal efficiencies over 90% within 30 min for the adsorption of hazardous organic compounds (e.g., phenolic and antibiotic micropollutants) in static tests. Experiment results and density functional theory (DFT) simulation revealed that the synergy of hydrogen bonding, π-πinteraction, and micropore preservation dominates the adsorption. Further dynamic adsorption experiments showed that the removal efficiency and equilibrium removal capacity towards bisphenol A by RH@MFNs packed bed up-flow column were 2.6 and 67 times higher than that of raw RH, respectively. The column adsorption fits well with the Thomas model and bed depth service time (BDST) kinetic model. The inherent macropores inside RH and the roughness caused by the spiky structures and mesopores outside RH, as well as the accumulated MFNs granules, can lead to local turbulence of water flow around RH@MFNs, enabling fast and efficient adsorption. This sustainable and cost-effective preparation of RH-based adsorbents sheds light on the rational design of biomass waste adsorbents for realistic wastewater.

In situ preparation of a multifunctional adsorbent by optimizing the Fe2+/Fe3+/Mn2+/HA ratio for simultaneous and efficient removal of Cd(II), Pb(II), Cu(II), Zn(II), As(III), Sb(III), As(V) and Sb(V) from aqueous environment: Behaviors and mechanisms.

Multiple potentially toxic elements (PTEs) often coexist in practical wastewater environment, which poses serious risks to the ecological environment and human health. However, few of the reported adsorbents are capable of simultaneously and effectively removing multiple PTEs from wastewater due to the unique properties of each element. In this work, a multifunctional adsorbent FMHs was developed by optimizing Fe2+/Fe3+/Mn2+/HA ratio, and applied to remove Cd(II), Pb(II), Cu(II), Zn(II), As(III), Sb(III), As(V) and Sb(V) from aqueous solution. Results revealed that the adsorption data obeyed the Elovich, Sips and Redlich-Peterson models in the mono-component system, and the maximum adsorption capacity of FMHs was superior to most adsorbents reported in the literatures. In addition, FMHs retained considerable removal capacity after four cycles, and maintained excellent adsorption performance under the interference of different environmental factors (including pH, ionic strength, co-existing ions and humic acid). In the multi-component system, FMHs also presented high adsorption capacity for all the selected PTEs, especially for Sb(III/V) and Pb(II). Characterization results confirmed that various removal mechanisms, such as precipitation, surface complexation, ion exchange, electrostatic attraction and redox, were responsible for the capture of PTEs by FMHs.

Adsorption, separation and recovery properties of blocky zeolite-biochar composites for remediation of cadmium contaminated soil

Cadmium (Cd) contamination in soils is a global ecological threat. Conventional powdered biochar added to soil can temporarily immobilize Cd but is difficult to separate from soil, leading to secondary release of Cd and posing potential ecological and human health risks. The blocky biochar is also difficult to separate from the soil due to its fragile nature. One of the keys to overcome the difficulties in separating biochar from soil is to improve its mechanical strength. Blocky zeolite-biochar composites (ZBC) that have good mechanical strength were obtained after pyrolyzing the mixture of 50% feedstock and 50% zeolite powder at 400 °C. ZBC and NaOH-activated ZBC (ZBCa) were applied to remove Cd from soil. After sieving Cd-loaded ZBC and ZBCa from soil, the bioavailable Cd content in the soil decreased by 59.70% and 68.54%, respectively. Zeolite contributed to improving both adsorption performance and mechanical properties of the composites. After repeating the process of “remediation-sieving-desorption-regeneration” three times, the recoveries of ZBC and ZBCa were above 97.00%, and regeneration rates were 48.70–83.26%, respectively. Under simulated mechanical sieving conditions, ZBC and ZBCa lost only 4.06% and 5.40% of their mass and retained their integrity. Remediation of Cd-contaminated soil with blocky zeolite-biochar composite is sustainable and safe because the removal of bioavailable Cd from soil is permanent rather than a temporary decrease of bioavailability. This study provides a reference for the preparation of separable and recyclable adsorbents for the removal of contaminants from soil.

A review of adsorption intensified by microwave irradiation from absorbent preparation to separation processes

Compared with the traditional heating modes, microwave technology is promising to intensify adsorption processes, due to its ability to accelerate the production rate of adsorbents and achieve adsorption equilibrium faster. This review paper describes the state-of-the-art field of microwave technology used for the adsorption separation, with a particular focus on microwave assisted preparation of various adsorbents, including metals, high molecular polymers, biology, and composite adsorption materials. The mechanisms of microwave-intensified adsorbents preparation and processes of adsorption separation, as well as the practical applications of microwave techniques in the adsorption/desorption field are explained and discussed. Finally, efforts to promote microwave intensification technology to industrial use in the field of adsorption and open questions in the development of industrial-scale microwave-assisted techniques are outlined.

Preparation of Porous Silica Nanoparticles by Chemical Etching for Removal of Paraquat from Aqueous Solution

In t his study, solid silica nanoparticles (sSiO2 NPs) were chemically etched using sodium hydroxide solution as an etchant to synthesize porous silica nanoparticles (pSiO2 NPs). Etchant dosage and etching time were optimized to obtain the optimum etching condition providing the effective removal of paraquat (PQ). High removal efficiency of PQ by the synthesized pSiO2 NPs was obtained over 90% using 11.1 mL of 1.25 M NaOH and 12 h for the etching process. SEM and TEM images showed that the porosity of pSiO2 NPs increased with increase of the etchant dosage and etching time. The increment of porosity of pSiO2 NPs enhanced the PQ removal efficiency. FTIR result indicated that the characteristic functionalities of silica remain after the etching process. After optimum condition of etching obtained, the adsorption behavior of PQ was investigated. Several key factors influencing the adsorption efficiency, i.e., initial solution pH, initial concentration, and adsorption time were optimized. The maximum removal efficiency of PQ (~98%) by the pSiO2 nanoadsorbent was obtained using 100 mg L-1 of PQ solution at pH ~7 within 5 minutes. The maximum adsorption capacity (qmax) of the pSiO2 NPs for the PQ removal was 65.7 mg g-1. The pSiO2 nanoadsorbent is effective adsorbent for the PQ removal due to the development of a facile synthetic method for adsorbent preparation, rapid adsorption process, and comparable qmax value with other PQ adsorbents.

Alkali Etching Hydrochar-Based Adsorbent Preparation Using Chinese Medicine Industry Waste and Its Application in Efficient Removal of Multiple Pollutants

The annual discharge (6–7 million tons per year) of Chinese medicine industry waste (CMIW) is large and harmful. CMIW with a high moisture content can be effectively treated by hydrothermal carbonization (HTC) technology. Compared with CMIW, the volume and number of pores of the prepared hydrochar increased significantly after alkali etching (AE), and they had abundant oxygen-containing functional groups. These properties provide physical and chemical adsorption sites, improving the adsorbent activity of the alkaline etching of Chinese medicine industry waste hydrochar (AE-CMIW hydrochar). However, few studies have investigated the adsorption of organic dyes and heavy metals in mixed solutions. This study proposed a method of coupling HTC with AE to treat CMIW and explored the potential of AE-CMIW hydrochar to remove metal ions and organic dyes from mixed solution. We analyzed the removal rates of metal ions and organic dyes by the adsorbents and investigated their differences. The results showed that the lead ion, cadmium ion, and methylene blue could be efficiently removed by AE-CMIW hydrochar in a mixed solution, with removal rates of more than 98%, 20–57%, and 60–80%, respectively. The removal rates were different mainly due to the various electrostatic interactions, physical adsorption, differences in the hydrating ion radius of the metal ions, and functional group interactions between the AE-CMIW hydrochar and the lead ion, cadmium ion, and methylene blue. This study provides a technical method for preparing multi-pollutant adsorbents from CMIW, which enables efficient utilization of organic solid waste and achieves the purpose of treating waste with waste.

Efficient removal of heavy metal ions from wastewater and fixation of heavy metals in soil by manganese dioxide nanosorbents with tailored hollow mesoporous structure

Heavy metals in wastewater and soil pose serious threats to the ecological environment and human health. Chemical modification and composite design are the main design strategies for high-performance heavy metal adsorbents. However, in this study, a unique way was adopted to improve the adsorption performance of MnO2 by tailoring its hollow mesoporous structure (HMN). Unmodified HMN which has good stability under acidic conditions was directly used for adsorption and fixation of heavy metals in wastewater and soil. The adsorption capacity of HMN has been greatly improved compared with other MnO2 adsorbents, and its adsorption capacities for Pb2+, Cu2+ and Cd2+ reached 897.0, 437.5 and 354.3 mg g−1, respectively. Such high adsorption performance is rarely seen in manganese-based adsorbents. Purification results of laboratory wastewater and industrial wastewater showed that it has good application prospect for actual environmental water samples. The adsorption mechanism mainly includes physical adsorption, electrostatic adsorption, surface complexation (oxygen sites and hydroxyl groups) and ion exchange between Na+ and heavy metal ions. In addition, HMN can effectively passivate heavy metals in contaminated soil and reduce their leaching concentration to improve soil safety. This improvement in the performance of adsorbents by tailoring their structures is instructive and provides insight and approach for the design and preparation of advanced adsorbents.

Biomass-Based Hydrothermal Carbons for the Contaminants Removal of Wastewater: A Mini-Review.

The preparation of adsorbents with eco-friendly and high-efficiency characteristics is an important approach for pollutant removal, and can relieve the pressure of water shortage and environmental pollution. In recent studies, much attention has been paid to the potential of hydrothermal carbonization (HTC) from biomass, such as cellulose, hemicellulose, lignin, and agricultural waste for the preparation of adsorbents. Hereby, this paper summarizes the state of research on carbon adsorbents developed from various sources with HTC. The reaction mechanism of HTC, the different products, the modification of hydrochar to obtain activated carbon, and the treatment of heavy metal pollution and organic dyes from wastewater are reviewed. The maximum adsorption capacity of carbon from different biomass sources was also evaluated.

Optimized preparation of gangue waste-based geopolymer adsorbent based on improved response surface methodology for Cd(II) removal from wastewater

Resource utilization of gangue solid waste has become an essential research direction for green development. This study prepared a novel gangue based geopolymer adsorbent (GPA) for the removal of Cd(II) from wastewater using pretreatment gangue (PG) as the main raw material. The ANOVA indicated that the obtained quadratic model of fitness function (R2 > 0.99, P-value <0.0001) was significant and adequate, and the contribution of the three preparation conditions to the removal of Cd(II) was: calcination temperature > Na2CO3:PG ratio > water-glass solid content. The hybrid response surface method and gray wolf optimization (RSM-GWO) algorithm were adopted to acquire the optimum conditions: Na2CO3:PG ratio = 1.05, calcination temperature of 701 °C, solid content of water glass of 22.42%, and the removal efficiency of Cd(II) by GPA obtained under the optimized conditions (GPAC) was 97.84%. Adsorption kinetics, adsorption isotherms and characterization by XRD, FTIR, Zeta potential, FSEM-EDS and BET were utilized to investigate the adsorption mechanism of GPAC on Cd(II). The results showed that the adsorption of Cd(II) from GPAC was consistent with the pseudo-second-order model (R2 = 0.9936) and the Langmuir model (R2 = 0.9988), the adsorption was a monolayer adsorption process and the computed maximum Cd(II) adsorption (50.76 mg g−1) was approximate to experimental results (51.47 mg g−1). Moreover, the surface morphology of GPAC was rough and porous with a specific surface area (SSA) of 18.54 m2 g−1, which provided abundant active sites, and the internal kaolinite was destroyed to produce a zeolite-like structure where surface complexation and ion exchange with Cd(II) through hydroxyl (-OH) and oxygen-containing groups (-SiOH and -AlOH) were the main adsorption mechanisms. Thus, GPAC is a lucrative adsorbent material for effective Cd(II) wastewater treatment, complying with the “high value-added” usage of solid wastes and “waste to cure poison” green sustainable development direction.

Investigation of CO2 adsorption performance of amine impregnated adsorbents using amine-support matching strategies

Supports and the organic amine type are the main factors affecting the performance of adsorbents. Currently, researchers are focusing on the development of supports, but their high cost limits the applications. In addition, there is a lack of studies on the mechanism of matching organic amines to supports. This paper presents a feasible strategy including the preparation of low-cost mesoporous nano-SiO2 (B-SiO2) support from blast furnace slag (BFS). A series of adsorbents were obtained by impregnating with different organic amines on the B-SiO2 support to identify the most suitable amine type for B-SiO2. The results showed that the matching degree four amines with B-SiO2 was TETA > TEPA > PEHA > PEI in order. TETA at 35 wt.% was the best matched amine for B-SiO2, exhibiting the highest CO2 adsorption capacity of 112.89 mg/g and the best adsorption energy Eads = −87.21 kJ/mol at 80 ℃. This is mainly due to two reasons. On the one hand, TETA is easily dispersed in the pores of the support, which not only effectively prevents the agglomeration effect and improves the accessibility of the active site, but also facilitates the inhibition of amine leaching. On the other hand, TETA has the least steric hindrance and the highest affinity for CO2, thus reducing the mass transfer resistance and improving the adsorption performance. In addition, four adsorption kinetic models were developed. The Avrami model was the best fit for four adsorbents. It indicates that the adsorption mechanism of this type of adsorbent is a combination of physical and chemical adsorption. This study reveals the matching rules between amine species and supports, and provides theoretical guidance for the preparation of solid amine-based adsorbents.

Research on Preparation of Metal Adsorbents Incorporating Macrocyclic Compound and Based on Biomass Wastes

Research on Preparation of Metal Adsorbents Incorporating Macrocyclic Compound and Based on Biomass Wastes