Adsorption Process Research Articles

Adsorption sites and interactions of pigments in molasses-based distillery effluent on starch-based composites: Ternary competitive adsorption and theoretical calculations

The pigment present in molasses-based distillery effluent constitutes a primary factor influencing its degradation. Adsorption is an effective approach to eliminate pigment from wastewater. In this study, a cationic cassava starch (CCS) magnetic composite (CCS@Fe3O4) was prepared and used as adsorbents for the removal of undesirable pigments. The adsorption behaviors of caffeic acid (CA), gallic acid (GA), and melanoidin (ME) on CCS@Fe3O4 in the wastewater were investigated using single and ternary competitive adsorption systems. The equilibrium adsorption capacities of CA, GA, and ME on CCS@Fe3O4 were 197.04, 195.55, and 623.97 mg/g at the optimized conditions (0.3 mg/mL CCS@Fe3O4 dosage, temperature of 38 °C, and pH of 7). The adsorption kinetic model showed that chemisorption accounted for most of the adsorption of CA, GA, and ME on CCS@Fe3O4. The adsorption mechanisms of pigments on CCS@Fe3O4 were explored at the molecular level through quantum chemical calculations. The electrostatic potentials (ESP), average local ionisation energy (ALIE), and Fukui indices calculation indicated that the quaternary ammonium group in CCS@Fe3O4 was more susceptible to electrophilic reactions. The CC and benzene rings in CA and GA, and the COO- in ME, represent sites of attack for quaternary ammonium during adsorption. Furthermore, the competitive adsorption results, adsorption energy, and electron transfer data demonstrated that the adsorption capacity of CCS@Fe3O4 for pigments followed the order ME>GA>CA. Overall, the competitive adsorption mechanisms of CA, GA, and ME on CCS@Fe3O4 were unveiled, with quantum chemical calculations offering crucial insights into the adsorption process.

Adsorption of Chromium (VI) and Lead (II) in Synthetic Solutions Using Tamarindus Indica Fruit Peel

The problem of water pollution persists and, in some cases, has been getting worse since many of the industries that are currently installed in developing countries do not comply with established standards. In order to reduce water pollution, various environmental standards have been established that aim to regulate the introduction of contaminating agents into water and, thereby, control the degree of alteration of the quality of the vital liquid. Adsorption allows minimizing the generation of toxic waste and the recovery of the metal. The objective of the work was to study the bioadsorption of Cr (VI) and Pb (II) using the dry peel of <i>Tamarindus indica</i>. We worked at different pH values and concentration levels. The determination of the chemical-physical parameters was carried out at the Empress Geominera Oriente. Adsorption isotherms were performed using the Langmuir, Freundlich and Dubinin-Radushkevich models, resulting in the maximum bioadsorption capacity of Cr (VI) and Pb (II) by biomass being 3.83 and 15.63 mg/g, respectively. reaching maximum removal percentages of 90.8%. The values of mean free energy of adsorption obtained from the Dubinin-Radushkevich model in Cr (VI) and Pb (II) were 10,000 kJ/mol, respectively, showing that, for these experimental conditions, the adsorption process is of a chemical nature.

Landfill leachate treatment by incorporating MWCNTs assisted adsorption and coagulation process

Landfill leachate treatment by incorporating MWCNTs assisted adsorption and coagulation process

Effects of interlayer-modified layered double hydroxides with organic corrosion inhibiting ions on the properties of cement-based materials and reinforcement corrosion in chloride environment

Developing novel, environmentally friendly, and efficient corrosion inhibitors is of great significance for improving the durability of marine concrete against chloride ion erosion. This paper aims to explore the potential of layered double hydroxides (LDHs) as nanocontainers, incorporating organic corrosion inhibitors between LDHs layers to synergistically enhance their effectiveness. In this study, Mg/Al-pAB-LDH was synthesized through the interlayer modification of LDHs with an organic corrosion inhibitor, p-aminobenzoic acid (pAB), employing a calcination-rehydration method. Chloride ion (Cl−) adsorption behavior was quantitatively and qualitatively analyzed and the effect on mortar properties was investigated. The corrosion resistance of steel bars in the mortar was assessed under chloride salt simulated concrete pore solution (SCPs) and chloride salt wet-dry cycles via electrochemical tests and microscopic characterization of Mg/Al-pAB-LDH. The results demonstrate that Mg/Al-pAB-LDH efficiently captures Cl− and releases corrosion-inhibiting ions pAB, with the adsorption process conforming to pseudo-second-order kinetics and Langmuir adsorption isotherm. Mg/Al-pAB-LDH enhances the pore structure of mortar, effectively improving mechanical properties and resistance to chloride ion penetration, with the optimal effect observed at a 4 % addition rate. Mg/Al-pAB-LDH demonstrates outstanding corrosion resistance to steel bars in both SCPs and mortar. In SCPs, it serves as a corrosion inhibitor by adsorbing Cl− and releasing pAB, whereas in mortar, it functions as a corrosion inhibitor by enhancing the physical barrier effect of mortar, adsorbing Cl−, and releasing pAB. This study demonstrates the promising potential of utilizing Mg/Al-pAB-LDH as a novel corrosion inhibitor to mitigate the corrosion of steel bars in marine concrete.

Continuous recovery of tellurium and cadmium from simulated CdTe leachates using a fixed-bed-column adsorption system

Rare element resource (Te) loss and heavy metal (Cd) pollution, derived from waste photovoltaic CdTe cells, have attracted considerable attention in the cleaner production and environmental protection field. However, there are several technical barriers in conventional adsorption strategies for the continuous recovery Te(Ⅳ) and Cd(Ⅱ) due to single-component recovery, inefficient adsorbent utilization and less automation. Herein, this work presented a fixed-bed-column adsorption system for the continuous adsorption recovery of tellurium and cadmium from a simulated CdTe leachate using functional sludge-based adsorption fillers (LDO/SF and EDTA@LDH/SF) that prepared from water-processing sludge via hydrothermal synthesis, thermal activation and surface modification technologies. Breakthrough curves were analyzed for adsorption columns, considering initial concentration, flow rate, and filler height, with parameters evaluated using the Thomas and BDST models to determine the optimal separation parameters. During the continuous adsorption process, the column adsorption system with the filler layer height of 4 cm and liquid delivery rate of 1 mL/min can be used for continuous separation of more than 1000 mL of a simulated CdTe leachate and exhibits adsorption efficiencies of more than 96% and 82% for Te(Ⅳ) and Cd(Ⅱ), respectively. More importantly, the elution procedure was used to treat the column adsorption system with ion adsorption acceptances of 83% and 90% for Te(Ⅳ) and Cd(Ⅱ), respectively. Meanwhile, the functional sludge-based fillers demonstrated great regeneration and recycling capabilities, thus maximizing the utilization of adsorbents and saving treatment costs. This study has established a robust technical solution for the continuous recovery of tellurium and cadmium from simulated leachates, providing a practical framework for evaluating the efficiency of adsorption filler columns in actual applications.

Mesoporous Fe3O4@SiO2@La nanocomposite for efficient methylene blue removal from wastewater

This study investigates the synthesis and application of Fe3O4@SiO2@La mesoporous nanocomposites for methylene blue (MB) removal from wastewater. The successful synthesis of the nanocomposite was confirmed by various characterization techniques including FE-SEM, XRD, BET/BJH, and FT-IR. The adsorption efficiency of the nanocomposite for MB removal was evaluated under different operating conditions, including initial solution pH, adsorbent dosage, contact time, and temperature. The results revealed that the nanocomposite demonstrated optimal performance at neutral pH (pH=7), with an adsorbent dosage of 0.01 g, a contact time of 5 min, and 25 °C. Kinetic studies revealed pseudo-second-order kinetics, indicating chemisorption as the rate-limiting step. Langmuir and Freundlich isotherms were applied to describe the adsorption process. The nanocomposites demonstrated excellent reusability and high removal efficiency in real wastewater samples. The enhanced MB removal efficiency of the Fe₃O₄@SiO₂@La nanocomposites is attributed to electrostatic interactions, π-π stacking, and hydrogen bonding between MB and the adsorbent surface. Overall, the synthesized nanocomposites offer a promising and efficient solution for MB removal from wastewater, demonstrating potential for practical applications in environmental remediation.

Integrated spectral based monitoring, optimization and control of the combined ozonation and powdered activated carbon adsorption process to remove organic micropollutants from secondary effluent

In this study, an innovative approach for the integrated monitoring, optimization and control of the combined ozonation (O3) and powdered activated carbon (PAC) adsorption process is introduced making use of spectral surrogates (UVA254 and EEM-PARAFAC components). The combined O3-PAC process is designed to remove organic micropollutants (µP) from secondary effluent. Therefore, the removal of 6 µP with varying ozone reactivity was systematically studied in both O3 and PAC as stand-alone systems and in the combined O3-PAC system. For the latter, adsorption experiments were performed with µP spiked into ozonated secondary effluent (sequential system) and with µP spiked into the initial secondary effluent before ozonation (integrated system). In accordance with Swiss standards, the goal was to achieve 80% atrazine removal (as a model O3 recalcitrant compound) at optimized O3 and PAC doses. An ozone dose ranging from 0.45 to 0.65 mg O3/mg DOC was more cost-effective in promoting subsequent PAC adsorption (less than 40%), particularly at low PAC doses (1-2 mg PAC/mg (initial (DOC))). The classical ideal adsorbed solution theory (IAST) model could not be used to predict the subsequent PAC dose after ozonation in the integrated system. Therefore, correlation models were established between (i) the reduction of spectral surrogates during both O3 and PAC dosing and µP removal, (ii) the reduction of spectral surrogates during ozonation and the related PAC dose of the subsequent adsorption process and (iii) between the reduction of spectral surrogates during ozonation and the integrated process. Based on these correlation models, an online spectral control strategy was developed and implemented. Finally, the optimal dosing strategy for 80% atrazine removal was determined as 0.5 mg O3/mg DOC and 1.4 mg PAC/mg (initial) DOC.

Thermodynamics and Kinetic Study for Removal of Orange-G Dye from Aqueous Solution by Nano Composite

In this study, where graphene oxide was prepared by Hummer method, while copper oxide was prepared in the green way using (capparies spinosa) plant extract as a reducing agent, these oxides were diagnosed as well as the binary nanocomposite by several techniques including Fourier Transform Infrared Spectroscopy (FTIR), X-rays diffraction , and field Emission scanning electron microscopy (FESEM), after that the superimposed (GO/CuO) was used to adsorbent the orange G dye ( Orange - G) from its aqueous solutions, A number of factors affecting adsorption were studied (equilibrium time, surface weight, pH, concentration effect, temperature). The results showed that the ideal time for adsorption of the orange dye (orange-G) on the surface of the nanocomposite (GO/CuO) was (30min), the best ideal weight for dye removal was (0.05gm), the best concentration was (20ppm), and the best acid function was (pH=2). After that, the adsorption kinetics were also studied by applying the pseudo first and second order of adsorption. The results showed that the adsorption process follows the false second-order kinetics. The thermodynamic functions of the removal process were also studied, and it was found that the value of (DH) is negative for the surface of the composite (GO/CuO) with dye. Meaning the adsorption process is exothermic, and that the DG0 has negative value, meaning that the adsorption processes occur spontaneously. positive DS0 values indicate that the molecules are becoming less bound

Advanced nano modification of ecofriendly glauconite clay for high efficiency methylene blue dye adsorption

This research focuses on the utilization of nano glauconite clay as an environmentally friendly sorbent for the removal of cationic dyes, particularly Methylene Blue (MB), from polluted water. The glauconite clay was sourced from the El Gidida region of Egypt and subjected to grinding in a laboratory-type ball mill to ensure homogeneity and increase the active sites available for the adsorption process. The resulting ball milled nano clay (BMNC) was characterized using techniques such as X-ray fluorescence (XRF), Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The concentration of MB dye was monitored using UV–Vis spectroscopy to assess the adsorption capacity of BMNC under various conditions including pH, time, dose, and temperature. The optimal conditions for the adsorption process were determined to be a pH range of 7–8, a contact time of 60 min, and a dose of 200 ppm, resulting in an adsorption capacity of 128 mg/g. This process demonstrated both low cost and high speed. The adsorption mechanism of MB on the BMNC surface was evaluated through kinetics, adsorption isotherms, and thermodynamics. The experimental data indicated an endothermic, spontaneous, and thermodynamically favourable adsorption process, which was further supported by simulated modelling results using Forcite program. The in-silico data aligned well with the experimental findings. Additionally, the study assessed the interference of salts, metal ions, and other dyes on MB adsorption onto BMNC, showing promising results. These findings strongly support the effectiveness of our sorbent substrate under challenging conditions.

Adsorptive removal of Fe and Cd from the textile wastewater using ternary bio-adsorbent: adsorption, desorption, adsorption isotherms and kinetic studies

Ternary bio-adsorbent was synthesized by using sisal fiber as a base with the integration of conductive polymer; polyaniline (PANI), supported with zero-valent iron nanoparticles by chemical activation with potassium hydroxide. The activation temperature impact on adsorption properties of Sisal fiber composite activated carbon was studied. The activation temperatures had a major effect on adsorption process as 100% removal efficiency was attained at 800 °C activated temperature. Scanning electron microscopy (SEM) was used for surface analysis of the adsorbent. Adsorption isotherms (Langmuir, Freundlich and Temkin) were examined and the negative values of 1/nF\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$1/n_{F}$$\\end{document} demonstrated that the adsorption data does not match with Freundlich model for chemisorption. The pseudo second order and Elovich kinetics correlation coefficients for the retention of Fe and Cd to solid-phase interface at SF-800/NP/PANI (C) offered a better correlation for the bio-adsorption of Fe and Cd than pseudo first order kinetic. However, the pseudo second order kinetic attained a surpassing interaction for the bio-adsorption of Fe (0.989) than Cd (0.966); while the Elovich kinetic attained a surpassing interaction for the bio-adsorption of Cd (0.975) than Fe (0.945). The recovery and recycling stability of the bio-adsorbent composites were studied.

Adsorption behavior of nano polyethylene for bensulfuron-methyl in an aqueous environment

Agricultural plastic film, which is widely used to maintain heat and moisture during agricultural production, could gradually degrade into micro- and nano-scale polyethylene plastic fragments when not properly treated. The polyethylene plastic fragments, with ideal properties to carry hydrophobic compounds, interact with pesticide molecules, forming co-exposed residues that persist in the environment. In this work, a small and representative nano-polyethylene particle (PE-NPs, 500 nm) were selected as the adsorption carrier, and bensulfuron-methyl, a commonly used herbicide for crops (e.g. rice and wheat) covered under agricultural plastic films, was chosen as the target analyte to investigate their adsorption behavior. The adsorption equilibrium time of bensulfuron-methyl on PE-NPs increases(6–12 h) with the increase of plastic dosage(500 mg/L-2000 mg/L). The adsorption capacity showed an increasing and then decreasing trend as the dosage of plastic increased, with the highest value achieved at around 500 mg/L. The adsorption behavior was influenced by environmental factors, for example, adsorption was significantly inhibited at pH=9.0 or NaCl concentrations above 0.05 mg/g or dissolved organic matter (oxalic acid) concentrations above 10 mg/L. In addition, The adsorption of bensulfuron-methyl aligned relatively close with pseudo-secondary kinetics and the Freundlich model, suggesting that surface adsorption, intraparticle diffusion, and mass transfer might play a role in the process of non-uniform multilayer adsorption. The adsorption thermodynamics experiment indicated that the adsorption process was spontaneous, heat-absorbing, and mainly physisorption.

Rapid Degradation Of Dye Effluents With A SnS Catalyst: A Sustainable Approach Using Natural Light Under Ambient Conditions.

Dye degradation presents a persistent challenge in addressing water pollution. While several methods, including adsorption, biodegradation, and advanced oxidation processes, have been extensively explored, photocatalysis remains one of the most effective techniques. Conventional photocatalytic dye degradation processes often rely on expensive light sources and are time-intensive. Herein, we synthesized a SnS catalyst using solvated metal atom dispersion (SMAD) method, using Sn foil and sulfur powder. The catalyst exhibited remarkable performance, achieving complete degradation of methylene blue within 2 minutes under ambient room light, without the need for any external light source. Similar degradation efficiency was achieved for methyl orange. To evaluate the role of light for the degradation, control experiments were conducted in the dark using methylene blue as a model dye. Although the degradation rate was slightly reduced, the catalyst still facilitated dye degradation in the absence of light. Additionally, the catalytic performance was tested with four other dyes under natural light, all of which yielded promising results, demonstrating the versatility and effectiveness of the SnS catalyst in dye degradation. This work highlights the potential of the SnS catalyst for efficient and rapid dye degradation under both light and dark conditions, offering an energy-efficient solution for wastewater treatment.

Adsorption and Morphology Analysis of Bovine Serum Albumin on a Micropillar-Enhanced Quartz Crystal Microbalance.

The adsorption of bovine serum albumin (BSA), a widely used blood plasma protein, onto poly(methyl methacrylate) (PMMA) surface is a fundamental phenomenon attracting increasing interests in molecular biology, cell culture, immunology, diagnostics, and vaccinology. The nanostructured PMMA surfaces have shown a considerable effect on the BSA adsorption process. However, the effect of microstructures (e.g., micropillars) on BSA adsorption has seldom been studied. This research reports on the development of an acoustic resonance based method to explore the adsorption of BSA proteins on PMMA micropillars in terms of surface coverage, apparent binding constants, and pH-induced morphology variation. A theoretical model is developed to understand the frequency changes of QCM induced by BSA adsorption by taking into consideration the effects of the hydrodynamic force and an equivalent BSA/liquid layer formed on the micropillar surface. In addition, it was found that the resonance of micropillars with a quartz crystal microbalance (QCM) substrate significantly influenced BSA adsorption on micropillar surfaces.

A hierarchical porous Fe3O4-COOH@H-ZIF-67 composite as magnetic solid-phase extraction adsorbent for benzimidazole pesticides

A hierarchical porous structural magnetic zeolite imidazolate framework-67 composite (Fe3O4-COOH@H-ZIF-67) was prepared through directly mixing the H-ZIF-67 and glutaric anhydride functionalized Fe3O4 nanospheres, of which the H-ZIF-67 was synthesized through a double template pore size regulation method. The successful preparation of Fe3O4-COOH@H-ZIF-67 composite was confirmed based on the material characterization using different techniques. The prepared composite was applied in the efficient removal of four benzimidazole pesticides (BZDs) in water using magnetic solid-phase extraction (MSPE) process. The results of static and dynamic adsorption experiments indicate that the adsorption of BZDs on Fe3O4-COOH@H-ZIF-67 follow pseudo-second-order kinetics, the Langmuir model fitted well with the adsorption data (R2 are all higher than 0.9969), and the maximum adsorption capacity for BZDs are 7.44–31.11 mg/g. Meanwhile, the adsorption mechanism study indicate that both hydrogen bonding and coordination play important roles during the adsorption process of BZDs. Finally, the developed MSPE method was combined with HPLC analysis and applied in the removal of BZDs from simulated pesticides wastewater. The removal rate was 82.76–96.18 %, and the treated samples met the requirements of the maximum residue limits of CBZ in the national standard GB 21523–2008. In addition, the adsorbent can be used at least three times and the extraction efficiency changed within 3 % after being stored in dry atmosphere at room temperature for 90 days. The results of this work manifested that Fe3O4-COOH@H-ZIF-67 composite can be used for removal and analysis of BZDs in complex samples.

Selective adsorption of cationic dye by κ-carrageenan-potato starch bio-hydrogel: Kinetics, isotherm, and thermodynamic studies

An eco-friendly κ-carrageenan/potato starch bio-hydrogel is designed for the efficient removal of methylene blue (MB) dye from water. The incorporation of potato starch was successfully confirmed through XRD, FT-IR, and SEM analysis, while TGA highlighted the hydrogel's thermal stability. Batch adsorption experiments demonstrated excellent MB removal efficiency, with a maximum adsorption capacity of 116.1 mg/g under optimal conditions (initial dye concentration: 100 mg/L, contact time: 180 min, temperature: 20 °C, adsorbent dosage: 1.6 g/L, and pH: 11). FT-IR analysis indicated that electrostatic interactions and hydrogen bonding primarily govern the adsorption process. The adsorption followed pseudo-second-order kinetics and fitted well with the Langmuir isotherm model. Thermodynamic studies revealed that the adsorption was exothermic and spontaneous. A key feature of this bio hydrogel is its selective affinity for the cationic dye MB, in a mixture with Acid Orange (AO) and other cationic dyes (Rhodamine B (Rh B) and crystal violet (CV)). The adsorbent also demonstrated impressive reusability, maintaining 93 % of its efficiency after five cycles, highlighting its potential for sustainable and cost-effective water treatment.

Resource Utilization of Rare-Earth-Rich Biomass and Ammonia Nitrogen Effluent from Mining

The post-treatment of heavy metal-enriched plants in mining areas and the purification of ammonia and nitrogen pollution in water bodies are significant for the ecological environment of ionic rare earth mining areas. Herein, we focused on the biochar production potential of Dicranopteris pedata, characterizing biochar prepared by an oxidative modification process and an iron modification process. We conducted adsorption experiments to comparatively investigate the adsorption performance of biochar on NH4+ and studied the fertilizer application and migration toxicity of the adsorbed biochar for rare earth elements (REEs). Results indicated that ~332.09 g of biochar could be produced per unit area of D. pedata under 100% clipping conditions. The Brunauer–Emmett–Teller (BET) specific surface area of oxidized biochar (H2O2BC) increased, and the pore size of iron-modified biochar increased. The adsorption behavior of biochar toward NH4+ was well represented by the pseudo-second-order and Langmuir models. H2O2BC demonstrated the strongest adsorption of NH4+ with maximum theoretical equilibrium adsorption of 43.40 mg·g−1, 37.14% higher than that of pristine biochar. The adsorption process of NH4+ on biochar is influenced by various physicochemical mechanisms, including pore absorption, electrostatic attraction, and functional group complexation. Furthermore, the metal ions in the biochar did not precipitate during the reaction process. The adsorbed NH4+ biochar promoted the growth of honey pomelo without risking REE pollution to the environment. Therefore, it can be applied as a nitrogen-carrying rare earth fertilizer in low rare earth areas. This study provides a theoretical basis and technical support for the phytoremediation post-treatment of rare earth mining areas and the improvement of ammonia nitrogen wastewater management pathways in mining areas.

Facile preparation of photothermal and superhydrophobic melamine sponge for oil/water separation and anti-icing

The preparation of superhydrophobic sponges with excellent physiochemical performance, affordability, and versatility is still a big challenge. Herein, a photothermal and superhydrophobic melamine sponge has been successfully achieved by decorating lignin particles (LPs)@MXene composite onto the skeletons of melamine sponge (MS) via the self-polymerization of dopamine. The obtained superhydrophobic MS (labeled as MS@PDA/LPs@MXene) shows a water contact angle of 153.7°, and maintains surface superhydrophobicity under harsh conditions (i.e., acidic, alkaline environments, high temperatures, frictional damage, and icing/de-icing cycles). Notably, the MS@PDA/LPs@MXene exhibits an exceptional oil adsorption capacity of carbon tetrachloride up to 143.6 times of its own weight, a high separation efficiency of 99.3 %, and a retained separation efficiency of 98.9 % after 15 cyclic adsorption processes, respectively. Owing to a synergistic photothermal effect of PDA and LPs@MXene, the MS@PDA/LPs@MXene possesses a maximum surface temperature of 62.8 °C under solar irradiation (1.0 kW/m2, 1 sun), and realizes the ice-free property at a low temperature of −17.9 °C (relative humidity, 90 %) on a continuous cooling stage under solar irradiation (0.5 sun). Furthermore, the LPs@MXene composite coating can be applied on various substrates (i.e., Al sheet, Cu sheet, filter paper, carbon cloth, steel mesh and NdFeB magnet) to obtain surface superhydrophobicity, showing excellent anti-corrosion property for the permanent NdFeB magnet. Thus, this paper proposes a facile and cost-effective strategy to prepare superhydrophobic melamine sponge with multifunctional properties, and provides new insights into the rational design of high-performance superhydrophobic sponges for their applications in oil/water separation and anti-icing.

Incrimination and impact on recovery times and effects of BN nanostructures on antineoplastic drug-electronic density study.

By delivering the drug to the intended cell location, the use of nanomaterials in the drug delivery system may influence how the patient receives the medication and may assist in mitigating severe side effects. Density functional theory was used to assess the use of boron carbon nitride nanocages (BNCNCs), boron nitride (BNNSs), and boron carbon nitride nanosheets (BNCNSs) as melphalan (Mln) drug carriers in both the gaseous and fluid phases. We systematically examined the dipole moment, density of states, frontier molecular orbital, and optimal adsorption energy to understand the targeted drug delivery potential of these nanostructures. Adsorption energy analysis revealed that in both gas and water media, Mln drug adsorption takes place spontaneously on all the conjugated structures. The occurrence of adsorption energy as physisorbed energy suggests that the process is reversible, and desorption can take place with a much lower energy input. This physical contact is appropriate for the unquestionable unloading of Mln medications to the intended location. The reactivity is higher in BNNSs and BNCNSs, while the stability is higher in BNCNCs. The recovery time shows a shorter time for BNNSs and BNCNSs, while BNCNC shows a potential desorption time in higher temperature. These conclusions are corroborated by the results of the quantum theory of atoms in molecules (QTAIM). After the interaction analysis, it was observed that the BNCNCs can act as potential carriers for the melphalan. From dipole moment analysis, all three nanostructures show a high hydrophilic nature but quite higher in BNCNCs after doping in both media. Overall, all the structures show the potential carrier for melphalan drug. The quantum mechanical approach, or DFT, has been used to study the fundamental structural, electrical, thermodynamic, and other aspects of proposed structures to develop an acceptable Mln drug detector. The adsorbate and all adsorbents were optimized via the hybrid B3LYP functional and the 6-311G + + (2d, p) basis set approach prior to the adsorption process. The Gaussian 09 package was used at 298K as the constant temperature and 1 atm as the constant pressure. The structures are examined using the same functional models for solvation analysis-6-311 G + + (2d, p) and B3LYP-as well as the polarized continuum model (PCM) model as the foundation set. Density of states was studied using GaussSum 3.0 software. The interaction studies QTAIM and RDG were studied using VMD and Multiwfn software.

Facile synthesis and characterization of magnetic iron oxide (Fe3O4)-loaded cationic amino-modified passion fruit shell nanocomposite and their application in removal of anionic Alizarin Red S dye from aqueous medium

A newly synthesized magnetic nanocomposite, iron oxide-loaded cationic amino-modified passion fruit shell (Fe3O4@CMPFS), was utilized as a sorbent to eliminate anionic Alizarin Red S (ARS) dye from the wastewater. The Fe3O4@CMPFS was characterized to confirm the properties by physicochemical methods such as VSM, XRD, pHPZC, BET, FTIR, and FE-SEM with EDX. Batch tests were conducted to study the adsorption process, focusing on factors like the solution pH (from 2.0 to 11), amount of Fe3O4@CMPFS (from 10 to 80 mg/30 mL), contact duration (from 0 to 240 min), agitation speed (from 0 to 400 rpm) and temperature (from 298 to 328 K). The optimal conditions for attaining a 92.3 % removal efficiency were found to be a pH of 2.0, 60 mg of Fe3O4@CMPFS, a contact time of 60 min, agitation at 250 rpm, and a temperature of 298 K. The Fe3O4@CMPFS was determined to have a pHPZC value of approximately 6.2. The kinetic data indicated that the adsorption of ARS onto Fe3O4@CMPFS followed the pseudo-second-order model (high R2 = 0.9919; low SSE = 1.5) and was governed by film and intraparticle diffusion mechanisms. Furthermore, the isotherm data fit well with the Langmuir model (high R2 = 0.9983; low χ2 = 12.69), suggesting monolayer adsorption behaviour. The maximal sorption uptake of ARS on the Fe3O4@CMPFS was determined to be 233.4 ± 3.174 mg/g at 298 K through the Langmuir model. The estimated ΔH° (18.3 kJ/mol) and ΔS° (82 J/mol K) indicate the endothermic and enhanced randomness at the adsorbent/solute interface. The negative ΔG° values (−6.2298 to −8.7283 kJ/mol at 298–328 K) confirm spontaneous sorption dominated by physisorption. The Fe3O4@CMPFS composite had good recyclability and was easy to separate from water, which maintained excellent adsorption performance after eight regeneration cycles. The superb adsorption efficiency and recycling performance of Fe3O4@CMPFS provide a prospect way to remove ARS dye from industrial effluents.

Valorization of Eggshell as Renewable Materials for Sustainable Biocomposite Adsorbents—An Overview

The production and buildup of eggshell waste represents a challenge and an opportunity. The challenge is that uncontrolled disposal of generated eggshell waste relates to a sustainability concern for the environment. The opportunity relates to utilization of this biomass resource via recycling for waste valorization, cleaner production, and development of a circular economy. This review explores the development of eggshell powder (ESP) from eggshell waste and a coverage of various ESP composite sorbents with an emphasis on their potential utility as adsorbent materials for model pollutants in solid–liquid systems. An overview of literature since 2014 outlines the development of eggshell powder (ESP) and ESP composite adsorbents for solid–liquid adsorption processes. The isolation and treatment of ESP in its pristine or modified forms by various thermal or chemical treatments, along with the preparation of ESP biocomposites is described. An overview of the physico-chemical characterization of ESP and its biocomposites include an assessment of the adsorption properties with various model pollutants (cations, anions, and organic dyes). A coverage of equilibrium and kinetic adsorption isotherm models is provided, along with relevant thermodynamic parameters that govern the adsorption process for ESP-based adsorbents. This review reveals that ESP biocomposite adsorbents represent an emerging class of sustainable materials with tailored properties via modular synthetic strategies. This review will serve to encourage the recycling and utilization of eggshell biomass waste and its valorization as potential adsorbent systems. The impact of such ESP biosorbents cover a diverse range of adsorption-based applications from environmental remediation to slow-release fertilizer carrier systems in agricultural production.