Preparation Of Adsorbents Research Articles

Hydrothermal-calcination synthesis of lithium orthosilicate microspheres for high-temperature CO2 capture

In recent years, the Li4SiO4 adsorbent has become a promising candidate for high-temperature CO2 capture. The fabrication of micro-structured Li4SiO4 could enhance the capture performance effectively. However, there exists a conflict between the purity and the morphology of prepared micro-structured Li4SiO4. This study proposed a novel hydrothermal-calcination method, which could produce Li4SiO4 microspheres with great morphology and relatively high purity. The physicochemical properties, CO2 capture performance and forming mechanisms of Li4SiO4 microspheres are evaluated and investigated systematically. It is found that the hydrothermal process could fabricate micro-spherical LiOH@Li2SiO3 precursor, which was further converted to Li4SiO4 microspheres during the subsequent calcination process. The LiOH@Li2SiO3 precursor could not only maintain the microstructure but also reduce the Li4SiO4 generation temperature, thus improving the morphology as well as the purity of obtained Li4SiO4 microspheres. As a result, the adsorbents could reach a CO2 capture capacity of 0.167–0.222 g/g within 30 min's adsorption under 15 vol.% CO2, and their cyclic stability are diverse depending on the used calcination temperatures. The hydrothermal-calcination contributes to the future preparation of high-performance Li4SiO4-based CO2 adsorbents.

A novel amidoxime-functionalized covalent organic framework adsorbent for efficient lead ion removal: synthesis and adsorption mechanism

Lead ions are highly toxic heavy metal ions and Pb(Ⅱ) in wastewater threatened seriously human health and environment. Therefore, an effective adsorbent must be developed to remove lead ions from wastewater. In this study, a polycrystalline amidoxime covalent organic framework (DBCC-NHOH) is synthesized by a post-modification method for the elimination of lead (II) from wastewater. The successful preparation of adsorbent (DBCC-NHOH) is demonstrated by the oxygen appearance in SEM-EDS pattern and conversion of -CN to C=N-O and C-N in the FT-IR pattern. DBCC-NHOH is a crystalline porous material and its pore size, specific surface area and pore volume are 3.419nm, 28.154 m2/g and 4.2ⅹ10-8 m3/g respectively. The optimum conditions for the adsorption of Pb(II) by DBCC-NHOH are temperature 298K, time 180min, and pH 5. The maximum adsorption of DBCC-NHOH was 221.37mg/g. Kinetic and thermodynamic investigations indicate that adsorption of Pb(II) by DBCC-NHOH is a monolayer chemisorption and exothermic process. Selectivity experiments indicate that DBCC-NHOH can adsorb Pb(II) efficiently and selectively in complex multi-ion systems. In addition, the adsorption percentage of DBCC-NHOH remained up to 83.20% after five adsorption-desorption experiments. The XPS and FT-IR analyses and DFT results indicated that DBCC-NHOH utilized amidoxime function group to realize the high efficiency of Pb(II) adsorption by electrostatic attraction and chelation.

Preparation of New Carbonaceous Adsorbents Based on Agricultural Waste and Its Application to the Elimination of Crystal Violet Dye from Water Media

Preparation of New Carbonaceous Adsorbents Based on Agricultural Waste and Its Application to the Elimination of Crystal Violet Dye from Water Media

Optimization of Magnetic Biochar Preparation Process, Based on Methylene Blue Adsorption.

The search for low-cost and effective adsorbents for the removal of organic dyes from contaminated water is urgently needed. The substantial amount of waste mushroom cultivation substrates generated in practical production can serve as an ideal material for the preparation of adsorbents. In this study, we investigated the main control parameters affecting the performance of magnetic mushroom substrate biochar and optimized the process of preparing biochar by using the Plackett-Burman and central composite design methods. Various analytical techniques including SEM, EDX, BET, and VSM were used to characterize the biochar. The results indicate that the carbonization temperature had the most significant impact on the yield and adsorption performance of biochar. Under the conditions of a carbonization temperature of 600 °C, a carbonization retention time of 1 h, and an impregnation ratio of 0.1, the yield and methylene blue adsorption value of magnetic biochar were 42.54% and 2297.04 μg/g, respectively, with a specific surface area of 37.17 m2/g. This biochar effectively removed methylene blue from the solution, demonstrating a high economic efficiency for wastewater treatment and pollution control. Furthermore, the adsorption-desorption cycle studies revealed its excellent stability and reusability. Additionally, based on the response surface methodology, a three-dimensional surface model of the adsorption performance of magnetic biochar under different carbonization conditions was established, providing a theoretical basis for the preparation of magnetic biochar from agricultural wastes.

PE/PP fibrous adsorbents with bifunctional groups of tertiary amine and phosphate prepared by electron beam induced co-grafting for heavy metal adsorption of both cationic and anionic forms in acidic conditions.

A novel fabric adsorbent having bifunctional groups of tertiary amine and phosphate was prepared by co-graft polymerization of 2-diethylaminoethyl methacrylate (NMA) and 2-hydroxyethyl methacrylate phosphate (PMA) onto a polyethylene/polypropylene nonwoven fabric (PE/PP NF) under low-energy electron beam acceleration. The process involved pre-irradiating the fabric and immersing it in the comonomer solution for grafting. The kinetics of radiation-induced graft polymerization at a total dose of 100 kGy was investigated. For pre-irradiation at 100 kGy, the optimum condition offering highest degree of grafting was at 12 wt% of NMA, 8 wt% of PMA and 4 h of reaction time. The adsorption of anions using hydrogen chromate (HCrO4−) or Cr(VI) and cations using lead (Pb(II)), cadmium (Cd(II)) and copper (Cu(II)) in aqueous solution was carried out. The results demonstrated that the bifunctional adsorbent was able to adsorb both heavy metal anionic and cationic ions from water. The co-grafted adsorbents with tertiary amine and phosphate were able to adsorb 85% Cr(VI) anion and 29% Pb(II) cations from mixed Cr(VI) and Pb(II) solution at pH 3.0 and 71% Pb(II), 13% Cd(II) and 31 % Cu(II) from mixed Pb(II), Cd(II) and Cu(II) solution at pH 5.0. The unique achievement of this study is its hypothesis that a bifunctional adsorbent can be prepared from radiation-induced graft polymerization of two different monomers onto NF, along with proof that the prepared bifunctional adsorbent can actually absorb both cationic or anionic heavy metals forms. Additionally, the adsorbent's preparation offers a rapid and straightforward one-step grafting technique. Therefore, the new bifunctional adsorbents can remove heavy metal ions in aqueous solution, either in the cation or anion form, thus offering highly promising applications in industrial wastewater treatment.

Preparation of Calcium-based Phosphate Adsorbent and Mineral-rich Humic acid Fertilizer from Biomass ash and Bamboo by Hydrothermal-pyrolysis: Performance and Mechanism

Biomass ash (BA) contains alkaline cations such as K, Ca, and Mg. Due to its high pH, direct application to the soil may result in soil salinization. Composting of BA with organic matter is an effective strategy, but the composting cycle is long and there is a large amount of insoluble residue in the product. Therefore, this research proposed for the first time using the hydrothermal method to rapidly convert BA and bamboo powder (BP) into water - soluble fertilizer (WSF) within 2 hours. The insoluble hydrothermal residue was further converted into calcium - rich biochar phosphorus adsorption material by a simple pyrolysis process. WSF was neutral and contained humic acid and elements like K, Ca, Mg, and Si. A 14 - day wheat hydroponic experiment showed that the addition of 0.0125% WSF increased the fresh weight of wheat by 18.77% compared with deionized water. The calcium - based biochar adsorbent produced by pyrolysis had an ideal adsorption capacity of up to 113.6mg P g-1 for phosphate in water, higher than many existing reports. The adsorption mechanisms mainly included surface precipitation, ion exchange, and electrostatic attraction. Moreover, the calcium - rich biochar sample slowly released phosphorus into water after adsorbing phosphate. When the pH was 3 or 4, the removal rate of Pb2+, Cd2+, and Cu2+ at 15 - 20 mg L-1 was as high as 99%. This indicated its potential as a slow - release fertilizer and heavy metal remediation agent. This research provided a new way of thinking for the treatment and disposal of BA.

Two-Step Preparation of Asphalt-based Porous Carbon Adsorbent with Superior C2H6/CH4 Selectivity for Ethane Recovery from Natural Gas

Efficient recovery of ethane from natural gas is of industrial importance, yet it poses considerable challenges. Herein, we report the two-step green preparation of asphalt-based carbon adsorbent AsCs with exceptional C2H6/CH4 selectivity and high capacity, where the KOH usage can be significantly reduced by 75% than conventional chemical activation processes. More importantly, the resulting AsC-0.75-900 exhibits exceptional C2H6/CH4 separation performance with the IAST selectivity of 30.74 and ethane capacity of 4.53 mmol/g at 298 K and 100 kPa. Notably, even at the low pressure of 10 kPa, its ethane uptake remains high at 2.25 mmol/g, comparable to many advanced MOFs. Molecular simulation was used to elucidate the adsorption mechanism. Fixed-bed experiments further demonstrate dynamic separation performance, achieving complete separation of a C2H6/CH4 binary mixture (10:90, v/v) at ambient condition. In addition to its superior separation performance, AsC-0.75-900 offers inherent structural stability and cost-effectiveness, positioning it a highly promising candidate for ethane recovery from natural gas.

PREPARATION OF THERMOCHEMICALLY ACTIVATED CARBON ADSORBENTS BASED ON COTTON STEM AND COTTON SHELL AND THEIR IR SPECTROSCOPY ANALYSIS

This article discusses the practical importance of adsorbents today, areas of application, and methods of obtaining activated carbon adsorbents based on local raw materials. Preparation of adsorbents activated by the method of thermochemical activation based on cotton stalks and cotton bolls, functional groups in the obtained adsorbents were analyzed by IR spectroscopy.

Mg and Fe co-loaded biochar prepared by microwave-synergized K2FeO4 of marine biomass for efficient CO2 capture: Performance assessment and mechanism exploration

To overcome the limitations of complex preparation and suboptimal performance of CO2 adsorbents, the present work synthesized a polymetallic oxide-loaded biochar (MgO·FeOx@biochar) with good performance in one step using a green and simple method of microwave-synergized K2FeO4. MgO·FeOx@biochar-700–10-0.1 with a hierarchical porous structure, abundant adsorption sites and well-distributed basic sites was obtained by optimizing the preparation parameters, which had a good CO2 trapping performance of 4.92 mol/kg with a retention rate of 83.01 % over 20 cycles, and exhibited good selectivity for O2 and N2. CO2 capture by MgO·FeOx@biochar was predominantly driven by chemical interaction between surface adsorption sites and CO2, supplemented by microporous filling. The adsorption kinetics revealed that the CO2 adsorption rate of MgO·FeOx@biochar was influenced by the combined effect of membrane diffusion resistance and intraparticle diffusion resistance. This study established a theoretical basis and technical insight for the environmentally friendly and efficient preparation of high-performance biochar-based CO2 adsorbents.

Preparation of adsorbent from coal gasification slag for the treatment of waste water from lanchar and its adsorption mechanism

ABSTRACT Solid waste coal gasification slag has certain hardness, porosity, pore structure and specific surface area, etc. which can be utilized in environmental protection materials and other areas of high value. Yulin City, high-quality coal resources derived from the excellent quality of charcoal products, but its processing will produce a large number of high chemical oxygen demand (COD), high volatile phenol, high ammonia nitrogen ‘three high’ wastewater, the ecological environment is very harmful. The results of the modification of the refined coal gasification fine residue showed that the removal rates of the three were enhanced to 91%, 89% and 83%, respectively, after adsorption at a pH of 9.5, an injection ratio of 1:5 and 25 ℃ for 25 min. The reason is that the modification treatment significantly increased the specific surface area of the adsorbent from 103 m2/g to 606 m2/g, which effectively increased the adsorption active sites for the pollutant molecules. The adsorption process of COD from modified refining coal gasification slag for the treatment of charcoal wastewater was thermodynamically investigated. The thermodynamic study shows that the adsorption process of modified refining coal gasification slag on pollutants in the charcoal wastewater is an exothermic and spontaneous process.

Preparation, characterization and application of polymeric ultra-permeable biodegradable ferromagnetic nanocomposite adsorbent for removal of Cr(VI) from synthetic wastewater: kinetics, isotherms and thermodynamics

Hexavalent chromium (Cr(VI)) contamination in drinking water due to industrial activities is a growing worldwide concern. Cr(VI) concentrations exceeding a few parts per billion (ppb) can cause serious health problems such as asthma, blood cancer, kidney-related diseases, liver and spleen damage, as well as neurological system, immunological deficiencies, and reproductive issues. This study, thus, explored the feasibility of employing a novel polymeric ferromagnetic nanocomposite adsorbent made of low-cost, biodegradable, and ultra-permeable materials from pulp and paper sludge for adsorptive removal of hexavalent chromium (Cr6+) from synthetic wastewater. Vibrating-sample magnetometer (VSM), X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmet-Teller surface area (BET), and Fourier transform infrared (FTIR) were used to analyze the produced nanocomposite adsorbent. The Fourier transform infrared results confirmed the presence of adsorptive peaks attributed to −OH, −NH2, and FeO. Scanning electron microscopy micrographs revealed a porous adsorbent surface. XRD revealed the existence of the crystalline spinel-structured magnetite (Fe3O4) phase of iron oxide, while the saturation magnetization was established to be 26.90 emu/g. The Brunauer–Emmett–Teller analysis confirmed a slight decrease in the surface area of the nanocomposite adsorbent to 6.693 m2.g−1, compared to Fe3O4 (7.591 m2.g−1). The optimum conditions for Cr6+ removal were pH 2.0, 1.0 g/L adsorbent dose, room temperature (25°C), 120 min contact time, and 20 mg/L pollutant concentration. During removal, the Cr(VI) was adsorbed by electrostatic attraction and/or reduced to trivalent chromium Cr(III). At low starting Cr(VI) concentrations, chemisorption dominated the removal process, but as concentrations increased, physisorption became more significant. The prepared nanocomposite adsorbent presented exceptional removal efficiency of up to 92.23%, indicating that it may be useful for the adsorption of metal ions from industrial and household wastewater.

Integrating a high-energy activation method for the sustainable treatment of iron smelting slag, phosphogypsum, and arsenic-contaminated water

Metallurgy is one of the pillar industries in China, but metallurgy inevitably produces a large amount of industrial solid waste and heavy metal pollution. Phosphogypsum (PG) is a by-product of the production of wet-process phosphoric acid, and after the preliminary fieldwork, there is a very small amount of arsenic [As(V)] in some of the phosphorus ores, and there is a risk of heavy metal pollution. In the present study, the preparation of arsenic adsorbent (PG/IS) by doping iron smelting slag (IS) with PG as a base material was proposed and the preparation conditions were optimized by Response Surface Methodology. PG/IS was systematically characterized and its adsorption properties were investigated with respect to a variety of factors. PG/IS exhibits spontaneous endothermic chemical adsorption characteristics for As(V)，its adsorption process is more consistent with the pseudo-second-order kinetic model. Coordination complexation and chemical precipitation are the primary mechanisms by which PG/IS removes As(V). This study provides a new approach for phosphorus chemical enterprises to achieve green development and reduce industrial solid waste and As(V) emissions.

Efficient and sustainable recovery of Au(I) from thiosulfate solution by tri-n-butylphosphine functionalized chitosan microspheres with abundant pores

Thiosulfate as a green and environmentally friendly lixiviant has received great attention in the field of gold extraction. However, the problem of gold ion recovery in thiosulfate gold leaching solution has hindered the large-scale application of this technology. Here, tri-n-butylphosphine (TBUP) was used as a functional monomer to prepare an adsorbent (CTS-TBUP) with abundant pores through the ion crosslinking reaction of chitosan, which was used to recover Au(I) from Au[(S2O3)2]3− solution with high efficiency and large capacity. CTS-TBUP exhibited good potential for industrial applications with a gold loading capacity of 46.34 mg/g. CTS-TBUP exhibited a similar gold recovery performance for all pH ranges from 6 to 11, and the adsorption process of Au(I) on CTS-TBUP was well described by pseudo-second-order kinetics and Langmuir isothermal model. The mechanism by which CTS-TBUP adsorbs gold ions involves ligand exchange between TBUP and Au[(S2O3)2]3−. In addition, Au(I) on CTS-TBUP will be reduced to elemental gold by TBUP in CTS-TBUP. The mechanism of Au(I) adsorption by CTS-TBUP was also confirmed by density functional theory calculations, and confirmed the rationality of forming a complex with a coordination ratio of 2:1 between TBUP and Au(I) at the theoretical level. CTS-TBUP has a good affinity for gold ions in thiosulfate solution, which provides a new idea for the preparation of gold adsorbent.

Eco-friendly copper nanoparticles for acetamiprid pesticide mitigation in water effluents

Water pollution by pesticides is a significant environmental concern, given their extensive use in agriculture to meet food production demands. This study focuses on evaluating the effectiveness of biosynthesized copper nanoparticles in removing the pesticide acetamiprid (AMP). The degradation process is tracked by measuring the absorbance at 245 nm (AMP λmax) while considering variables such as adsorbent dosage, pH, and time. It provides valuable insights into the design and preparation of CuO nano adsorbents and their efficiency in purifying and remediating aquatic environments. The research investigated the ability of CuO nanoparticles, with an average size of 60 nm, to eliminate acetamiprid at very low concentrations (0.0005–0.01 mg/ml). The results showed that the nanoparticles could remove up to 97.5 % of AMP (0.01 mg/ml GT-CuO) after 90 min of contact time. Additionally, the study used the Langmuir isotherm model (R2 = 0.99125) and the pseudo-second order kinetic model (R2 = 0.98303) to model the adsorption of AMP on CuO NPs. Overall, CuO NPs derived from Glochidium tomentosum (GT) could offer a promising approach for adsorbing AMP pesticides.

Preparation and Performance Study of CaCl2 Composite Adsorbent Based on Rock Wool Board Suitable for Continuous Heat Storage/Release of Trombe Wall

Preparation and Performance Study of CaCl2 Composite Adsorbent Based on Rock Wool Board Suitable for Continuous Heat Storage/Release of Trombe Wall

Interdisciplinary Project-Based Learning of Fine Chemical Technology for Applied Chemistry Majors: Preparation of High Cationic Degree Cotton-Based Adsorbent

Interdisciplinary Project-Based Learning of Fine Chemical Technology for Applied Chemistry Majors: Preparation of High Cationic Degree Cotton-Based Adsorbent

Preparation of a Porous Spherical Adsorbent by Oil-In-Water-In-Oil Emulsion Polymerization for Phycocyanin Adsorption

ABSTRACT Phycocyanin is a protein with potential in food and medical applications. A porous spherical adsorbent was prepared by oil-in-water-in-oil emulsion polymerization. Oil and water phases containing surfactants and monomers, respectively, were emulsified, and the prepared emulsion was added to the oil phase to polymerize the porous spherical adsorbent. The concentration ratio of N,N-dimethylacrylamide and 2-dimethylaminoethylmethacrylate (DMAEMA) in the water phase was changed. The obtained spherical adsorbent had a size of about 150 μm and a water content of 90%, with macropores of several micrometers. Phycocyanin (20 kDa) of Nostoc commune was leached by the freeze and thaw method to prepare the solution. The adsorption data of the batch and column modes were evaluated by ordinary differential and partial differential equations, respectively, considering competitive adsorption, to obtain parameters of the mass transfer coefficient and saturated adsorption capacity. In the b\ sfer coefficient of phycocyanin decreased by about one-third, but the saturated adsorption capacity increased three-fold. In the continuous flow column, leached biomacromolecules other than phycocyanin had greater parameters of mass transfer and capacity. To prepare an adsorbent for the biomacromolecules, selective adsorption sites in the polymer matrix should be designed and prepared.

Preparation of N-Enriched GO Adsorbents and Their Properties for Selective CO2 Capture

Preparation of N-Enriched GO Adsorbents and Their Properties for Selective CO2 Capture

Evaluating the efficacy of palm waste in adsorption processes for wastewater treatment: A review

AbstractThe growing environmental concerns related to industrial effluents and waste underscore the urgent need for sustainable and cost‐effective wastewater treatment solutions. This review investigates the efficacy of palm waste‐derived adsorbents for removing heavy metals and organic pollutants from wastewater. It explores various modifications—including physical, chemical, and nanomaterial enhancements—applied to palm waste materials such as palm kernel shells, empty fruit bunches, and palm oil fuel ash, aimed at improving their adsorption capacities. The review reveals that these modified palm waste adsorbents demonstrate high removal efficiencies for contaminants like Cu(II), Pb(II), and organic dyes, often surpassing conventional adsorbents. Nonetheless, challenges remain, such as optimizing adsorbent preparation, understanding adsorption mechanisms in multi‐component systems, and enhancing adsorbent reusability. This review highlights the need for continued research to address these issues and advance the application of palm waste‐based materials in sustainable wastewater treatment.

Hydrothermal preparation of pharmaceuticals adsorbents from chitin and chitosan: Optimization and mechanism

Hydrothermal treatment of fishery waste-derived chitin (CT) and chitosan (CS) was performed to prepare biochar adsorbents for the removal of pharmaceuticals of environmental concern. By systematically studying the effect of treatment conditions on the biochar structure, the correlation between biochar properties and the adsorption capacities was clarified to optimize the adsorption performance. CS hydrochars obtained by lower-temperature treatment showed high adsorption capacities for the pharmaceuticals having carboxyl groups attributed to the electrostatic binding. A decrease in the density of available amines in CS hydrochars prepared at higher temperatures resulted in lower adsorption capacities and the manifestation of different adsorption mechanisms based on hydrophobic and π-π interactions. CT hydrochars showed lower adsorption capacities than CS hydrochars due to inefficient carbonization and lack of adsorption sites. The hydrochar adsorbents prepared in this study address simultaneously the problems of marine waste bioresource utilization and environmental cleaning from the emergent pollutants.