Maximum Sorption Capacity Research Articles

Zr4+-mercaptosuccinate MOF for the uptake and recovery of gold nanoparticles and gold ions under batch and continuous flow conditions

The increasing use of nanomaterials in commercial products has raised concerns regarding their potential effects on water quality and living organisms. So far, most sorbents available for removing nanosized inorganic pollutants from water rely on electrostatic interactions or entrapment in the sorbent pores. However, this limits their applicability in real wastewater samples containing nanomaterials with variable surface properties and sizes, along with high concentrations of competitive species such as inorganic salts and organics. Little attention has also been paid to the recovery of nanoparticles after sorption. In this work, a Zr4+-mercaptosuccinate metal organic framework (MOF) with free thiol groups was investigated as a sorbent for the removal of Au nanoparticles and Au3+ ions from water. Sorption occurs on the surface of the MOF via the formation of strong metal-thiolate chemical bonds enabling the fast uptake of noble metal nanoparticles and noble metal ions from water (within <1 h). The maximum sorption capacity was found to depend on the size of the Au nanoparticles and ranged from 8 to 41.5 mg/g. The surface functionalization of nanoparticles did not influence sorption performance, which was also maintained in natural waters of variable matrix complexity. The material was also efficient in fixed bed columns with an estimated maximum Au sorption capacity of approximately 7 mg/g, which is significantly higher than the environmental concentrations of Au nanoparticles and adequate for their removal from industrial wastewater. Importantly, the sorbed nanoparticles could be quantitatively recovered (>90 %), at the expense of material degradation, enabling their potential reuse.

Enhanced adsorption of phenolic compounds using biomass-derived high surface area activated carbon: Isotherms, kinetics and thermodynamics.

The progress of industrial and agricultural pursuits, along with the release of inadequately treated effluents especially phenolic pollutant, has amplified the pollution load on environment. These organic compounds pose considerable challenges in both drinking water and wastewater systems, given their toxicity, demanding high oxygen and limited biodegradability. Thus, developing an eco-friendly, low-cost and highly efficient adsorbent to treat the organic pollutants has become an important task. The present investigation highlights development of a novel adsorbent (CFPAC) by activation of Cassia fistula pod shell for the purpose of removing phenol and 2,4-dichlorophnenol (2,4-DCP). The significant operational factors (dosage, pH, concentration, temperature, speed) were also investigated. The factors such as pH = 2 and T = 20°C were found to be significant at 1.6g/L and 0.6g/L dosage for phenol and 2,4-DCPrespectively. Batch experiments were further conducted to study isotherms, kinetic and thermodynamics studies for the removal of phenol and 2,4-DCP. The activated carbon was characterised as mesoporous (specific surface area 1146 m2/g, pore volume = 0.8628cc/g), amorphous and pHPZC =6.4. At optimum conditions, the maximum sorption capacity for phenol and 2,4-DCP were 183.79mg/g and 374.4mg/g respectively. The adsorption isotherm was better conformed to Redlich Peterson isotherm (phenol) and Langmuir isotherm (2,4-DCP). The kinetic study obeyed pseudo-second-order type behaviour for both the pollutants with R2 > 0.999. The thermodynamic studies and the value of isosteric heat of adsorption for both the pollutants suggested that the adsorption reaction was dominated by physical adsorption (ΔHx < 80kJ/mol). Further, the whole process was feasible, exothermic and spontaneous in nature. The overall studies suggested that the activated carbon synthesised from Cassia fistula pods can be a promising adsorbent for phenolic compounds.

Uranium capture from aqueous solution using palm-waste based activated carbon: sorption kinetics and equilibrium

Carbonaceous materials produced from agricultural waste (palm kernel shell) by pyrolysis can be a proper type of low-cost adsorbent for wide uses in radioactive effluent treatment. In this context, the as-produced bio-char (labeled as PBC) and its sub-driven sulfuric acid and zinc oxide activated carbons (labeled as PBC-SA, and PBC-Zn respectively) were employed as adsorbents for uranium sorption from aqueous solution. Various analytical techniques, including SEM (Scanning Electron Microscopy), EXD (X-ray Diffraction), BET (Brunauer–Emmett–Teller), FTIR (Fourier Transform Infrared Spectroscopy), and Zeta potential, provide insights into the material characteristics. Kinetic and isotherm investigations illuminated that the sorption process using the three sorbents is nicely fitted with Pseudo-second-order-kinetic and Langmuir isotherm models. The picked data display that the equilibrium time was 60 min, and the maximum sorption capacity was 9.89, 16.8, and 21.9 mg/g for PBC, PBC-SA, and PBC-Zn respectively, which reflects the highest affinity for zinc oxide, activated bio-char, among the three adsorbents, for uranium taking out from radioactive wastewater. Sorption thermodynamics declare that the sorption of U(VI) is an exothermic, spontaneous, and feasible process. About 92% of the uranium-loaded PBC-Zn sorbent was eluted using 1.0 M CH3COONa sodium ethanoate solution, and the sorbent demonstrated proper stability for 5 consecutive sorption/desorption cycles.

Removal of chromium (VI) from aqueous solutions by granular composites based on laponite and alginate ionotropically cross-linked by iron and zirconium ions

The conducted research established the porous structure of the materials through low-temperature nitrogen adsorption. It was demonstrated that the nitrogen sorption isotherms for the investigated samples belong to Type IV with H4 hysteresis associated with bottle-like pores. The specific surface area of the granulated composite samples was determined, ranging from 99 to 111 m2/g. Additionally, it was shown that an increase in iron content in the samples leads to a reduction in micropore content. Active centers on the material's surface, primarily composed of hydroxyl groups, were investigated using infrared spectroscopy. The kinetics of chromium (VI) adsorption were explored, and it was established that the iron-to-zirconium ratio in the reinforcement solutions hardly affects the duration of establishing adsorption equilibrium, which is approximately 60 minutes. Pseudo-first-order and pseudo-second-order models were applied to describe the kinetics of the adsorption process. The dependence of the chromium (VI) removal efficiency on the solution pH was determined. It was demonstrated that the synthesized samples exhibited high adsorption in acidic conditions with a sharp decline when transitioning to neutral and alkaline environments. It was shown that the maximum sorption capacities of the synthesized granulated composite samples significantly depend on the ratio of iron and zirconium ions. One of the most efficient samples is that with 50% Fe and 50% Zr, exhibiting a maximum sorption capacity of 13.29 mol/g at pH 6. The use of Langmuir and Freundlich models allowed establishing the fundamental adsorption properties of the materials.

Kinetic, adsorption, and thermodynamic study of removal of Cr6+ by iron-rich natural clay minerals

The study explores the adsorption behavior of unmodified natural clay as an ecologically acceptable procedure in the treatment of toxic elements such as Cr6+ in wastewater. Batch experiments were conducted by stirring 30 ml of a Cr6+ solution and natural clay for 3 h at different temperatures, pH, Cr6+ loadings, and concentrations. Characterization of natural clay before and after adsorption was studied by XRD, FTIR, and BET for surface area, SEM, and EDX for surface topography. The Cr6+ content was analyzed by UV–visible spectrophotometer further, the mechanism of the process was illustrated by isotherm and kinetic studies. Cr6+ maximum sorption capacity obtained was 12.3 mg/g at pH 3. The overall process followed the Langmuir model elucidating monolayer adsorption as a major, in addition kinetics study (pseudo-2nd-order) describes accurately that chemisorption is a rate-controlling stage. Thermodynamics measurements indicated a spontaneous and endothermic process involved throughout the adsorption. Therefore, the study highlights the efficacy of unmodified natural clay as an efficient adsorbent for the elimination of Cr6+ from aqueous solution.

Chromium desalinization using novel chitosan functionalized iron oxide- biochar composites: Analysis, synthesis, characterization and adsorption performance

In the study, chitosan functionalized iron oxide incorporated with peanut shell biomass was prepared for potential adsorption of chromium (VI) from an aqueous media. The prepared material was characterized by modern spectroscopic methods for confirming the successful embedding. The adsorption experiments were conducted in batch systems. The experimental data showed robust removal of chromium supported by kinetic and equilibrium studies. The sorption data exhibited a strong agreement with the pseudo-second-order kinetics model, further confirming conformity with the Langmuir isotherm model. Adsorption studies were taken to find the effects of pH and time, reusability, ionic strength and presence of coexisting ions. The maximum sorption capacity was achieved as 14.28 mg g-1 at pH 4 and the optimum contact time was 40 minutes. The background electrolytes have much less effect on uptake efficiency and this green adsorbent can be utilized for up to four cycles. Additionally, a systematic approach was employed to ensure the precision and accuracy of the spectroscopic method. Calibration was linear in the range from 0.5 to 6.0 μg L-1 (R2 &gt; 0.99). The limits of detection (LOD) and quantification (LOQ) were 0.65 μg L-1 and 2.16 μg L-1, respectively. The relative standard deviation (RSD) was 7.62 % (n=7).

New color changing sorption material for effective removal of heavy metals from wastewater

Relevance. The need to purify water resources from Me(II) cations. Obtaining effective and cheap sorbents is one of the priority areas for water purification for various purposes. Namely, the sorbents, allowing the detection and adsorbing heavy metal cations in drinking or tap water and, at the same time, systematic monitoring of water quality in the environment. Aim. Synthesis of sorption material for effective removal of Me(II) cations from wastewater, study of the main parameters of new sorption material. Objects. Shanghai natural zeolite and its forms modified with polyethylene polyamine, 1,2-pyridylazonaphthol and epoxy resin (ED-20). Methods. Spectrophotometry. Results. A sorbent is proposed based on a combination of a surface layer of polyethylene polyamine, 1,2-pyridylazonaphthol and ED-20 epoxy resin, which is then successfully immobilized on zeolite for adsorption of metal cations Me(II)) from water. The synthesized sorbent makes it possible to diagnose its own efficiency by color changing of the surface after sorption of Me(II) cations. Competing cations of alkali and alkaline earth metals (water hardness salts) do not interfere with the adsorption of Me(II) cations. The maximum sorption capacity was 220 mg/g, which is comparable to other common sorbents. The sorbent also demonstrated the possibility of reuse after 10–12 cycles of desorption and regeneration of the color-forming component 1,2-pyridylazonaphthol. Desorption was carried out using 0.20 M HCl, then the sorbent was ready for being used without significant loss of its characteristics after washing with water. Restoration of the ability to color change was achieved by treating the sorbent in a 10–3 M aqueous solution of 1-(2-pyridylazo)-2-naphthol for 10 minutes.

High-efficiency selective enrichment of U(VI) from aqueous solutions by amidoxime-functionalized siliceous mesocellular foams

Siliceous mesocellular foams (MCFs) with high surface area, large pore volume and ordered mesoporous structure have a great potential in the capture of pollutants. To achieve the sorption of U(VI) with enhanced capacity and selectivity, amidoxime groups were modified on MCFs by optimizing the molar ratio of (2-cyanoethyl) triethoxysilane (CPTES) in silicon source from 0% to 30%. CPTES promoted the grafted amounts of amidoxime group (0–1.85 mmol/g) while resulted in the collapse of mesopores of amidoximated MCFs from 426.5 to 136.3 m2/g. Sorption behaviors of U(VI) at the interface of amidoximated MCFs and solutions were systematically investigated under various hydrochemical conditions. Amidoximated MCFs could capture U(VI) rapidly (4.0 h) with superior maximum sorption capacity (446.6 mg/g at pH 5.0 and T 298 K), and favorable reusability (67.8% of capacity remained after six recycles). Selective enrichment of U(VI) from artificial nuclide wastewater (201.5 mg/g of capacity, 16.08–33.61 of selectivity coefficients) and seawater (179.3 mg/g of capacity, 5.08–20.48 of selectivity coefficients) against the interference of heavy metals and nuclides were presented. This study provided a valuable reference for the preparation of sorbents with surface amidoximation and advanced porosity as well as a meaning option for the extraction of nuclides from aqueous solutions.

NIR-triggered drug delivery system based on tungsten disulfide nanosheets coated pH/temperature responsive polymer for controlled delivery of palbociclib: Release kinetics models

BackgroundPolymers that respond to changes in ambient conditions, such as physiological pH and temperature, have garnered increasing interest in the realm of drug delivery systems. In this study, a novel pH and temperature dual-responsive carrier was prepared for palbociclib delivery. MethodsThe tungsten disulfide nanosheets were functionalized with allyl glycidyl ether, allyl alcohol, and N-vinylcaprolactam, and then grafted with 2, 3-diaminopyridine. The in-vitro drug release was studied in simulated cancer (pH=5.6) and blood (pH=7.4) fluids at different temperatures. Significant FindingsThe in-vitro drug release test showed better release behavior at high temperatures in simulated cancer fluid compared to lower temperatures in simulated blood fluid, releasing about 87.53% of the entrapped drug within 6 h at 45 °C in simulated cancer fluid. The drug release shown the best fitting with the Korsmeyer-Peppas kinetic model. When the near-infrared laser irradiation was applied for 15 min, the drug release from the nanocarrier was three times higher than that without the laser irradiation. The maximum sorption capacity of the drug was achieved at approximately 79.04 mg g−1 at pH=8 for 45 min at 25 °C. The sorption procedure was found to follow the Langmuir isotherm and a pseudo-2nd-order kinetic model quite well.

Сорбция ионов Cu(II) и Fe(II) хлопковой целлюлозой, модифицированной диэтилентриамином

The authors have developed new effective sorbent based on chemically modified cotton cellulose. The modification process consists of two stages, including sequential treatment of cellulose with epichlorohydrin and diethylene triamine. The authors present &#x0D; the optimal modification conditions for the obtained sorbent. It allows ones’ to achieve the highest values of sorption capacity for the extraction of iron(II) and copper(II) ions from aqueous solutions. The authors investigated the kinetics and equilibrium of heavy metal ion sorption in the system "cellulose sorbent - aqueous solution of metal sulphate" for original and modified cotton cellulose. Processing of the kinetic experiment results indicates that the kinetics of metal ion sorption is described most correctly in the framework of the pseudo-second-order kinetics model. Isotherms of heavy metal ions sorption clearly indicate the growth of sorption capacity for the modified sorbent in comparison with the original one. Processing of experimental isotherms within the Langmuir model made it possible to determine the values of the maximum sorption capacity (A∞) of original and modified with diethylenetriamine cotton cellulose with respect to Cu(II) and FE(II) ions. It was found that the A∞ of the modified sorbent was about 3 times higher than the ultimate sorption capacity of original cotton cellulose towards iron(II) and Cu(II) IONS. Comparison of IR spectra of the original cellulose samples and cellulose treated with diethylenetriamine indicates the changes that occurred during chemical modification. The paper presents SEM images showing the changes in the surface structure of the modified sorbent compared to the original one.

Cu(II) AND Fe(II) ION SORPTION BY COTTON CELLULOSE MODIFIED WITH DIETHYLENETRIAMINE

The authors have developed new effective sorbent based on chemically modified cotton cellulose. The modification process consists of two stages, including sequential treatment of cellulose with epichlorohydrin and diethylene triamine. The authors present &#x0D; the optimal modification conditions for the obtained sorbent. It allows ones’ to achieve the highest values of sorption capacity for the extraction of iron(II) and copper(II) ions from aqueous solutions. The authors investigated the kinetics and equilibrium of heavy metal ion sorption in the system "cellulose sorbent - aqueous solution of metal sulphate" for original and modified cotton cellulose. Processing of the kinetic experiment results indicates that the kinetics of metal ion sorption is described most correctly in the framework of the pseudo-second-order kinetics model. Isotherms of heavy metal ions sorption clearly indicate the growth of sorption capacity for the modified sorbent in comparison with the original one. Processing of experimental isotherms within the Langmuir model made it possible to determine the values of the maximum sorption capacity (A∞) of original and modified with diethylenetriamine cotton cellulose with respect to Cu(II) and FE(II) ions. It was found that the A∞ of the modified sorbent was about 3 times higher than the ultimate sorption capacity of original cotton cellulose towards iron(II) and Cu(II) IONS. Comparison of IR spectra of the original cellulose samples and cellulose treated with diethylenetriamine indicates the changes that occurred during chemical modification. The paper presents SEM images showing the changes in the surface structure of the modified sorbent compared to the original one.

Enhanced copper removal by magnesium modified biochar derived from Alternanthera philoxeroides

Adsorption processes are being widely used by various researchers for the removal of heavy metals from waste streams and biochar has been frequently used as an adsorbent. In this study, a MgO-loaded biochar derived from Alternanthera philoxeroides (MAPB) was synthesized for the removal of Cu(II). Compared with other biochar absorbents, MAPB showed a relatively slow adsorption kinetics, but an effective removal of Cu(II) with a maximum sorption capacity of 1, 238 mg/g. The adsorption mechanism of Cu(II) by MAPB was mainly controlled by chemical precipitation as Cu2(OH)3NO3, complexation and ion replacement. Fixed bed column with MAPB packed in same dosage (1, 000 mg) and different bed depth (1.3, 2.6 and 3.9 cm) showed that the increased of bed depth by mixing MAPB with quartz sand could increase the removal of Cu(II). The fitted breakthrough (BT) models showed that mixing MAPB with support media could reduce the mass transfer rate, increase the dynamic adsorption capacity and BT time. Therefore, MAPB adsorbent act as a highly efficient long-term adsorbent for Cu(II) contaminated water treatment may have great ecological and environmental significance.

Synthesis characterization and sorption properties of nanoscale zero valent iron using red mud as the iron source: cadmium removal from spiked aqueous solutions

&lt;p&gt;The aim of the present study was to synthesize a sorbent material, nanoscale zero valent iron (n ZVI), using red mud as the iron source in the framework of circular economy. The sorbent synthesized was tested for Cd removal from spiked aqueous solutions. For the synthesis of the sorbent, iron reductive precipitation was used. The specific surface area (BET method) of the sorbent prepared was determined, while its surface composition, morphology, and texture were examined by powder X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM-EDX). The sorption efficiency of the sorbent produced was inve-1stigated with kinetic and equilibrium experiments, performed in batch conditions. MATLAB software was used to fit experimental data to Langmuir and Freundlich equations. The results of the study showed that with the described process, nanoscale zero valent iron was prepared with grain size 81 and 89 nm and specific surface area of 36.59 and 28.9 m2·g-1 depended on the synthesis procedure followed. The sorbent appeared to be efficient for Cd removal from spiked aqueous solutions. Kinetic experiments proved that equilibrium was achieved within 24h while the maximum sorption capacity as evidenced by equilibrium experiments was 65 mg·g-1. Data proved to follow the pseudo second order model and to fit better to the Langmuir equation.&lt;/p&gt;

The Use of Chitin for the Removal of Nitrates and Orthophosphates from Greenhouse Wastewater.

The study investigated the possibility of using chitin flakes as an unconventional sorbent for the removal of orthophosphates and nitrates from greenhouse wastewater (GW). The effluent parameters were as follows: 66.2 mg P-PO4/L, 566.0 mg N-NO3/L, 456.0 mg S-SO4/L, 13.7 mg Cl-/L, 721 mg Ca2+/L, 230 mg Mg2+/L, hardness 11.3 °dH, and pH 5.4. The scope of the research included determinations of the influence of pH on GW composition and the efficiency of nutrient sorption, the kinetics of nutrient sorption, the influence of the dose of chitin flakes on the effectiveness of nutrient binding and the maximum sorption capacity of the sorbent. The sorption of P-PO4 on the tested sorbent was most effective at pH 4, and the sorption of N-NO3 at pH 2. The equilibrium time of sorption of both nutrients from GW to chitin depended on the sorbent dose and ranged from 150 to 180 min. The sorbent dose of 40 g/L enabled removing 90% of orthophosphates and 5.7% of nitrates from the wastewater. The maximum sorption capacity of CH towards P-PO4 and N-NO3 contained in the GW was 3.20 mg/g and 3.04 mg/g, respectively. In turn, the sorption of calcium and magnesium ions on chitin flakes was completely ineffective.

Preparation and thermal properties of zeolite 13X/MgSO4-LiCl binary-salt composite material for sorption heat storage

Thermal energy storage can play a pivotal role in waste heat recovery and solar energy thermal utilization by balancing the time and space-mismatch between supply and demand of energy. Thermochemical sorption heat storage technology has gained the enormous interest for its ability to make use of the low-grade thermal energy. However, the slow sorption reaction kinetics of sorbents remains an obstacle for the large-scale industrial applications of thermochemical sorption heat storage technology. In this study, a new type of zeolite 13X/MgSO4-LiCl composite sorbent material has been fabricated by impregnating zeolite 13X with the mixed solution of MgSO4 and LiCl. The structural characteristics and sorption heat storage performance of composite adsorbents with different mass ratios of MgSO4 and LiCl were studied experimentally by scanning electron microscopy (SEM), full-automatic specific surface area and pore analyzer (ASAP), and thermogravimetry analysis-differential scanning calorimetry (TGA-DSC). The results indicate that binary-salt sorbents show the faster sorption kinetics and higher water sorption capacity compared to single salt sorbents. When the mass ratio of MgSO4 and LiCl is 2:1, the zeolite 13X/MgSO4-LiCl composite sorbent (XML-2/1) has the best sorption heat storage performance. Under the sorption temperature of 25 °C and relative humidity (RH) of 60 %, the maximum sorption capacity is 0.24 g/g, and the corresponding heat storage density of 458.3 kJ/kg can be achieved. The results indicate that the zeolite 13X/MgSO4-LiCl composite adsorbent can improve the sorption rate and heat storage density. Compared with pure zeolite 13X and zeolite 13X/MgSO4 composite sorbents, the addition of LiCl can effectively improve the sorption rate and sorption heat storage capacity. The findings of this investigation could promote the growing body of research on the mixed salt (binary-salt or multiple-salt) composite materials and new insights can be offered by broadening the application of zeolite-based composite materials in low-grade thermal energy storage for space heating, which can guide further research and development in this field and ultimately help facilitate the transition toward the clean energy.

Investigating contaminant leakage in sawtooth-configured non-pumping reactive wells: A sandbox test approach

Non-pumping reactive wells (NPRWs) are passive remediation technologies for contaminated groundwater that use various configurations of wells filled with reactive materials. This study evaluated the performance of sawtooth array NPRWs, which is a configuration that considers minimum well spacing for ground stability, and investigated contaminant leakage through them. A sandbox was constructed to observe point-by-point differences in cadmium (Cd) concentrations through the NPRWs. Groundwater flow and solute transport were simulated numerically to determine contaminant leakage and decontamination performance. Finally, the performance of the saw tooth-configured NPRWs was evaluated considering removal efficiency and longevity. The sandbox test results showed that the Cd concentrations exhibited very similar upgradient trends. Significant downgradient decontamination of Cd by the reactive materials was confirmed. Specifically, the Cd concentrations exhibited highly dispersed or wide spatial variations at each point, indicating contaminant leakage. The Langmuir sorption model, which uses the concept of maximum sorption capacity, was the most suitable for explaining the occurrence of contaminant leakage. The removal efficiency decreased over time because of the leakage of pollutants and the longevity was determined to be 890 h. The investigation of contaminant leakage provides a method for quantitatively assessing the performance of NPRWs facility and can be valuable in the design phase for optimizing NPRWs configurations, including suggesting safety factors to prevent leaks.

Extraction of gallium from carbon concentrate - Aluminum industry waste

A complex approach to the extraction of gallium from a carbon concentrate (CC), a waste product of the aluminum industry, was considered. Ashing of CC made it possible to remove the main component - carbon and obtain ash, which is an oxide mineral-like compound, from which gallium was leached with solutions of inorganic acids and their mixtures. The maximum degree of leaching (98%) of gallium was achieved with 6 M HCl for ash after ashing the CC at 600 °C. It was shown that Purolite anion exchangers with highly basic tertiary and quaternary ammonium base groups recovered gallium(III) from 2 to 10 M HCl, where the sorption equilibrium was attained after 60 min. The maximum extraction was observed from 6 M HCl. Under optimal conditions, the maximum sorption capacities for gallium(III) were achieved for Purolite A300 (2.7 mmol g−1) and Purolite A500 (2.2 mmol g−1) sorbents. Gallium(III) was quantitatively (99%) eluted from the sorbents with distilled water. Sorption of gallium(III) and its subsequent desorption with water made it possible to separate it from the predominant amounts of transition metal ions: Fe(III), Ni(II), Co(II), Zn(II), V(V) and other cations: Al3+, Ca2+, Mg2+, Na+ and K+. The addition of sodium hydroxide to the concentration of 200 g L−1 resulted in the cementation of gallium on aluminum gallama (liquid gallium‑aluminum alloy).

Sorptive Removal of 133Ba from Aqueous Solution Using a Novel Cellulose Hydroxyapatite Composite Derived from Cigarette Waste

133Ba is a hazardous radionuclide generated during the operation of nuclear power plants. 133Ba needs to be removed from waste solutions because its half-life (10.55 years) and gamma energy pose a significant threat to human health. Cigarette butt (CB) is a waste that causes serious environmental problems. Various types of adsorbent materials are prepared based on the cellulose in its structure. The focus of the present study is to synthesize a novel composite material derived from CBs and to investigate its 133Ba removal capability. Microfibrillated cellulose (MFC) obtained from CBs was modified with hydroxyapatite (HAp) via the co‐precipitation method and converted into a composite adsorbent for the removal of 133Ba ions. Response surface methodology (RSM) based on Box‐Behnken Design (BBD) was employed for the examination of process variables such as initial pH, metal concentration, and adsorbent amount on 133Ba sorption. XRD and FTIR data confirmed the successful isolation of cellulose and the modification of the cellulose surface with HAp. The model F-value (100.04) and R2 (0.99) suggested that the proposed model was significant. Optimum conditions were determined as initial pH of 8, contact time of 134 min, and concentration of 0.01 mol/L, and the barium sorption capacity of MFC‐HAp was found to be 0.75 mmol/g under these conditions. The maximum monolayer barium sorption capacity was determined to be 2.92 mmol/g. Combining cellulose and HAp to be a novel composite adsorbent is useful for reusing CB waste and promising for removing 133Ba ions from aqueous solutions.

Application of lithium modified ZIF-90 in a hybrid absorption-adsorption method for carbon capture

Herein, a lithium modified Zeolitic Imidazolate Framework-90 (ZIF-90-OLi) was used in a slurry with its organic ligand Imidazole Carboxaldehyde (ICA) water, and glycol to improve the process conditions for the capture system and enhance the sorption ability. The performance of this slurry was compared to two other slurries, one based on the parent ZIF-90 nanoporous material with ICA/water/glycol and another based on ZIF-8, its organic ligand Methylimidazole (MIm) and water/glycol. The comparison to ZIF-8 was done because of its use as a ZIF of reference in carbon capture. The maximum sorption capacity for CO2 by the alkali containing slurry was 7.19 mol/L and the maximum CO2/N2 selectivity was 222.93 compared to 2.72 mol/L and 121.63 for the ZIF-8/water/glycol/mlm slurry.

Chitosan-based foam composites for hexavalent chromium remediation: Effect of microcellulose and crosslinking agent content

Potentially toxic metal ions, such as hexavalent chromium (Cr6+), present in water concern the population's health due to their persistence, bioaccumulation potential, and high toxicity. Highly porous materials based on polysaccharides are promising technologies for metal removal due to their high surface area, biodegradability, and low toxicity. This study evaluated the effect of concentrations of microcellulose (0.5, 1, and 1.5 %) and glutaraldehyde (1, 2, and 3 %) in the adsorption capacity and mechanical properties of chitosan foams. The developed foams exhibited a three-dimensional structure with interconnected pores. Compared to foams without microcellulose, adding 1.5 % microcellulose increased up to 180 % in maximum stress supported by the foams and up to 135 % in Young's modulus. However, Cr6+ sorption capacity decreased with increasing microcellulose and crosslinking agent content due to the occupation of amino groups. Still, the foams exhibited a highly favorable sorption behavior, and the Sips isotherm model provided the best fit to the experimental data. The maximum sorption capacity reached approximately 1.4 mmol·g−1 at pH 4.0 and 25 °C. The foam structural integrity, enhanced mechanical properties, and efficient sorption capacity make them viable alternatives for environmentally friendly and cost-effective treatment of water contaminated with Cr6+ ions.