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The country's energy demand is experiencing rapid growth, and fossil fuels remain the primary resources to meet this increasing need. However, global warming poses a significant challenge for governments and industries worldwide. To address this issue, utilizing methane as a fossil fuel and implementing CO2 capture and sequestration can prove to be effective mitigation strategies. This paper presents an innovative idea to utilize unmineable coal seams in the Singrauli coal field for CO2 sequestration while extracting associated CBM to offset the cost of the sequestration process. The findings reveal that the field has great potential for CO2 sequestration. The estimated average maximum sorption capacities of CO2 and CH4 in the coal seams under in situ conditions of the basin are 39.50 m3/t and 11.15 m3/t, respectively. The total maximum sorption capacities of CO2 and CH4 in the potential coal seams are estimated to be 10,758.00 Mm3 and 3,215.00 Mm3, respectively. These results indicate that the unmineable coal seams in the Singrauli coalfield hold potential for CO2 sequestration and the extraction of available CBM from the coal seams. [ABSTRACT FROM AUTHOR]

A critical measure of the quality of pharmaceutical proteins is the preservation of native conformations of the active pharmaceutical ingredients. Denaturation of the active proteins in any step before administration into patients could lead to loss of potency and/or aggregation, which is associated with an increased risk of immunogenicity of the products. Interfacial stress enhances protein instability as their adsorption to the air‐liquid and liquid–solid interfaces are implicated in the formation of denatured proteins and aggregates. While excipients in protein formulations have been employed to reduce the risk of aggregation, the roles of albumin as a stabilizer have not been reviewed from practical and theoretical standpoints. The amphiphilic nature of albumin makes it accumulate at the interfaces. In this review, we aim to bridge the knowledge gap between interfacial instability and the influence of albumin as a surface‐active excipient in the context of reducing the immunogenicity risk of protein formulations. [ABSTRACT FROM AUTHOR]

The pursuit of incorporating eco-friendly reinforcing agents in polymer composites has accentuated the exploration of various natural biomass-derived materials. The burgeoning environmental crisis spurred by the discharge of synthetic dyes into wastewater has catalyzed the search for effective and sustainable treatment technologies. Among the various sorbent materials explored, biochar, being renewable, has gained prominence due to its excellent adsorption properties and environmental sustainability. It has also emerged as a focal point for its potential to replace other conventional reinforcing agents, viz., fumed silica, aluminum oxide, treated clays, etc. This study introduces a novel class of polymer nanocomposites comprising of lignin-based biochar particles and poly(ester amide urethane) matrix via a feasible method. The structural evaluation of these nanocomposites was accomplished using Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and powder X-ray diffraction. The polymer nanocomposites exhibited superior mechanical properties with an increment in tensile strength factor by 45% in comparison to its pristine matrix, along with an excellent toughness value of 90.22 MJm−3 at a low loading amount of only 1 wt%. The composites showed excellent improvement in thermal properties with a sharp rise in the glass transition temperature (Tg) value from −28.15°C to 84°C, while also championing sustainability through inherent biodegradability attributes. Beyond their structural prowess, these polymer nanocomposites demonstrated excellent potential as adsorbents, displaying efficient removal of malachite green and tartrazine dyes from aqueous systems with a removal efficiency of 87.25% and 73.98%, respectively. The kinetics study revealed the pseudo second order model to be the precision tool to assess the dye removal study. Complementing this, the Langmuir adsorption isotherm provided a framework to assess the sorption features of the polymer nanocomposites. Overall, these renewable biochar integrated polymer matrices boast remarkable recovery capabilities up to seven cycles of usage with an excellent dye recovery percentage of 95.21% for the last cycle, thereby defining sustainability as well as economic feasibility. [ABSTRACT FROM AUTHOR]

Porous silica-based adsorbents for hexavalent chromium (Cr(VI)) ion removal were prepared by the combined use of functionalization with (3-glycidyloxypropyl)trimethoxysilane and the grafting of branched and linear polyethyleneimine (BPEI and LPEI). LPEI was prepared from polyethyloxazolin by hydrolysis with HCl. The preparation of LPEI was identified by NMR measurements and the grafting of BPEI and LPEI on the silica beads was confirmed by an XPS analysis. The Cr(VI) ion adsorption of the obtained BPEI-grafted silica beads (BPEI–silica beads) was investigated as a function of the pH value, the content of amino groups, the temperature, the Cr(VI) ion concentration, and the molecular mass of the grafted BPEI chains. The Cr(VI) ion adsorption at pH 3.0 increased with an increase in the content of amino groups, and the maximum adsorption capacity of 1.06 mmol/g was obtained when the content of amino groups was at 2.17 mmol/g. This value corresponds to 589 mg/g−1.8KPEI, and the adsorption ratio of about 0.5 is a noteworthy result. The data fit to the pseudo-second-order kinetic model, and the suitability of this fitting was supported by the results that the adsorption capacity and initial rate of adsorption increased with the temperature. In addition, the equilibrium data followed the Langmuir isotherm model. These results clearly demonstrate that the Cr(VI) adsorption occurred chemically, or through the electrostatic interaction of protonated amino groups on the grafted BPEI chains with hydrochromate ( H C r O 4 − ) ions. A higher adsorption capacity was obtained for the silica beads grafted with shorter BPEI chains, and the adsorption capacity of BPEI–silica beads is a little higher than that of linear PEI-grafted silica beads, suggesting that the Cr(VI) ion adsorption is affected by the chain isomerism of PEI (linear and branched) as well as the molecular mass of the grafted PEI chains, in addition to the content of amino groups. The experimental and analytical results derived from this study emphasize that the BPEI–silica beads can be used as an adsorbent for the removal of Cr(VI) ions from an aqueous medium. [ABSTRACT FROM AUTHOR]

In this study, Adsorption characteristics of uranium from nitrate media onto a commercially accessible strong cation exchange resin, Marathon C, were investigated. The characteristics of Marathon C, before and after adsorption of uranium, were determined using scanning electron microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The influence of the different parameters, which may affect the process of uranium adsorption process from synthetic solutions and applying on real sample from uranium purification unit, had been tracked. Specifically, impacts of initial uranium concentration (40–300 mg/L), PH (1–8), phase ratio (0.2–1.2 g/L), contact time (2–360 min.) and temperature (& 25–50°C) on uranium removal, were studied. In addition, the sorption kinetics and equilibrium parameters were assessed. At the optimum conditions, the adsorption capacity of uranium at PH 4, 1 g Marathon C/L and 120 min were found to be nearly 131.58 mg g−1 at room temperature (& 25°C). The kinetics and isotherm studies could show that the uranium adsorption onto Marathon C is following the models of pseudo-second-order and Langmuir isotherm, respectively. The thermodynamic parameters had indicated that the adsorption of uranium is an exothermic and spontaneous process (∆H = −64.27 ± 0.01, ∆G = −22.57 ± 0.02). The detected results of uranium adsorption could reveal that Marathon C is a suitable material for adsorption of uranium from nitrate media and applying on real sample from uranium purification unit. [ABSTRACT FROM AUTHOR]

Sodium-rich zeolite A and zeolite X (FAU-type) samples were synthesised from LD-slag via fusion-assisted hydrothermal treatment. The physicochemical and thermal stability of the prepared samples were examined with the help of various characterisation techniques, namely, Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis (TGA) analysis at three different pH conditions and treatment time. Moreover, the sustainability of the crystalline phase and the corresponding zeolite network was evaluated from XRD, FTIR, TGA and Field-Emission Scanning Electron Microscopy (FESEM) analysis. Zeolite A depicts a unique cubical structure and is thermally more stable as compared to zeolite type-X. Also, zeolite A showed the highest dye removal efficiency of 98.13%, as compared to 94.47% for zeolite X, along with equilibrium sorption capacities of 25.30 and 23.57 mg g−1, respectively. In addition, the study proposes that both the synthesised adsorbents are effective and economically sustainable for cationic methylene blue adsorption. Furthermore, methylene blue adsorption was regulated by a multistage diffusion process that agreed with a pseudo-second-order kinetic model (R2 = 0.999 and 0.996 for A- and X-type zeolites). The Langmuir isotherm model best suited the equilibrium data, with monolayer adsorption capacities of 20 and 25.40 mg g−1, respectively. [ABSTRACT FROM AUTHOR]

Abstract Andesite was employed to effectively extract mercury(II) in an aqueous solution. After evaluating its characteristics, andesite was characterized by applying modern techniques such as BET and TGA methods. The study employed SEM and TEM measurements to analyze the variation in the surface shape and crystallinity of the metal due to adsorption. Using the EDX process, the chemical composition, weight, and atomic percentage of each element of andesite were determined. FTIR techniques were also used to confirm the TEM–EDX findings. Zeta potential was estimated. Cycles of regeneration and desorption have been examined. 99.03% was the highest uptake percentage. Adsorbent quantity (0.0025–0.05) g/L, contact time (5–60) min, pH (2–10), temperature (25–60) °C, and dose (0.0027, 0.0044, 0.0125, 0.0155, and 0.0399) mg/L all affect the amount of removal that increases with the increase in contact time, pH, dose, and temperature but drops as the metal ion concentration rises. The ideal values for contact time, pH, metal ion concentration, dose, and temperature were found to be, respectively, 30 min, 0.0155 mg/l, 0.02 g/l, and 40 °C. The calculation of thermodynamic parameters, including ΔH, ΔG, and ΔS, was imperative in establishing that the mechanism of heavy metal adsorption on andesite was endothermic, exhibiting a physical nature that escalated with temperature rise. The Freundlich adsorption equation's linear form is matched by the adsorption of mercury(II) on andesite; constant n was 1.85, 1.06, 1.1, and 1.1, whereas the Langmuir constant qm was found to be 1.85, 2.41, 3.54, and 2.28 mg/g at 25–60 °C. Furthermore, adsorption follows a pseudo-second-order rate constant of (3.08, 3.24, 3.24, and 13) g/mg/min under identical temperature conditions, as opposed to a first-order rate constant of 4, 3, 2.6, and 2. Hg2+, NH4 +, Cl−, Br−, NO3 −, SO4 2−, Na+, K+, H2S, and CH3SH were all extracted from wastewater by this application.

In this study, a discontinuous Galerkin (DG) finite element method is employed to solve the nonlinear equilibrium dispersive (ED) model, for the simulation of multi-component gradient elution chromatography using a liquid mobile phase in fixed-bed columns. The ED model comprises a set of coupled nonlinear convection-dominated partial differential equations integrated with nonlinear Langmuir type adsorption isotherms. Gradient elution, characterized by the gradual increase in eluent strength through variations in the chemical composition of the mobile phase, is analyzed. An investigation into the advantages of gradient elution chromatography in comparison to isocratic elution is conducted via a sequence of numerical test experiments that assess the influence of solvent strength, modulator concentration, gradient start and end times, and gradient slope on the elution profiles and temporal moments. It has been observed that gradient elution chromatography influences the behavior, shape, and propagation speed of elution profiles, which subsequently affect the cycle time and column efficiency. The results of this study provide significant insights that are critical for understanding, optimizing, and enhancing gradient elution chromatography. [ABSTRACT FROM AUTHOR]

Herein, we report the removal of methylene blue (MB) dye from water by Cu(II)-quinoxaline, 3,3-thiodipropionate mixed ligand coordination polymer synthesized as [Cu2(TDPH)4(QNX)]·DMF. Characterization of the synthesized material was carried out by elemental analysis, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), BET surface area analysis, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and UV–visible spectroscopy. ν(C = O) and ν(C–O) absorption bands were detected at 1735 and 1093 cm−1, respectively, while ν(C = N) was observed at 1608 cm−1 in the synthesized compound. The synthesized material was used as adsorbent for the removal of MB dye from aqueous solution using batch adsorption technique. The maximum adsorption capacity was found to be 7.9745 mg/g, while the maximum decolorization efficiency for the adsorbent was observed to be 99.04%. Adsorption data from the study fitted the Langmuir isotherm with an R2 value of 0.9815, while the adsorption kinetics followed the pseudo-second-order kinetic model with an R2 value of 0.9953. The results obtained from the study, therefore showed that the synthesized materials could be used as adsorbents in wastewater treatment. [ABSTRACT FROM AUTHOR]

The present research aimed to investigate the impact of some synthetic derivatives of pyridone (6-amino-1-(4-hydroxyphenyl)-4-(4-methoxyphenyl)-2-oxo-1,2-dihydropyridine-3,5-dicarbonitrile (PYR-2) and 6-amino-1-(4-hydroxyphenyl)-2-oxo-4-phenyl-1,2-dihydropyridine-3,5-dicarbonitrile (PYR-3))on copper corrosion inhibition behavior in HCl acid solution using electrochemical methods, including potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS). Using FTIR, 1HNMR, and mass spectroscopy methods, the two compounds ((PYR-2) and (PYR-3)) were confirmed and characterized. With the two compounds added to corrosive media, the double-layer capacitance value decreases. In the case of 18 × 10−5 M, they reached maximum efficiency of 91.9% and 90.3%, respectively. Having studied its behavior during adsorption on copper, it was concluded that it follows chemical adsorption and Langmuir isotherm and may be considered mixed-type inhibitors. [ABSTRACT FROM AUTHOR]

In this research, a novel nano-biocomposite material, namely, tungsten trioxide-Butea monosperma leaf powder (WO3@BLP), is an effective and eco-friendly adsorbent used for the mitigation of congo red (CR) and crystal violet (CV) dyes from its aqueous phase. The as-prepared WO3@BLP was characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), DLS analysis, and TGA. Many factors such as solution pH, WO3@BLP dose, temperature, contact time, and initial CR/CV dye concentrations were exploited to monitor the adsorption efficiency of WO3@BLP composites. The biosorption of both CR and CV dyes followed the Langmuir isotherm, with maximum adsorption capacities (qmax) reaching 84.91 mg g−1 for CR at pH 2.3 and 162.75 mg g−1 for CV at pH 8, fitting of kinetics data to the PSO model with closed values of qeexp (mg g−1) and qecal (mg g−1), i.e., 25.69 to 25.38 mg g−1 for CR dye and 29.06 to 29.08 mg g−1 for CV dye. The interaction mechanism behind the adsorption of CR and CV dyes onto the WO3@BLP bionanocomposite includes electrostatic interaction and surface complexation. The synthesized materials were tested for antifungal activity against three different Candida cells, i.e., C. albicans ATCC 90028, C. glabrata ATCC 90030, and C. tropicalis ATCC 750, by using broth dilution method on the minimum inhibiting concentration (MIC). Furthermore, the cytotoxicity of nano-formulated WO3@BLP was studied by in vitro hemolytic assay on a human host. Overall, this research presents a pioneering nano-biocomposite, WO3@BLP, as a sustainable adsorbent for CR and CV dye removal, adhering to Langmuir isotherm and pseudo-second-order kinetics. Its multifaceted approach includes elucidating interaction mechanisms, demonstrating antifungal activity, and assessing cytotoxicity, marking a significant advancement in environmental remediation. [ABSTRACT FROM AUTHOR]

Andesite was employed to effectively extract mercury(II) in an aqueous solution. After evaluating its characteristics, andesite was characterized by applying modern techniques such as BET and TGA methods. The study employed SEM and TEM measurements to analyze the variation in the surface shape and crystallinity of the metal due to adsorption. Using the EDX process, the chemical composition, weight, and atomic percentage of each element of andesite were determined. FTIR techniques were also used to confirm the TEM–EDX findings. Zeta potential was estimated. Cycles of regeneration and desorption have been examined. 99.03% was the highest uptake percentage. Adsorbent quantity (0.0025–0.05) g/L, contact time (5–60) min, pH (2–10), temperature (25–60) °C, and dose (0.0027, 0.0044, 0.0125, 0.0155, and 0.0399) mg/L all affect the amount of removal that increases with the increase in contact time, pH, dose, and temperature but drops as the metal ion concentration rises. The ideal values for contact time, pH, metal ion concentration, dose, and temperature were found to be, respectively, 30 min, 0.0155 mg/l, 0.02 g/l, and 40 °C. The calculation of thermodynamic parameters, including ΔH, ΔG, and ΔS, was imperative in establishing that the mechanism of heavy metal adsorption on andesite was endothermic, exhibiting a physical nature that escalated with temperature rise. The Freundlich adsorption equation's linear form is matched by the adsorption of mercury(II) on andesite; constant n was 1.85, 1.06, 1.1, and 1.1, whereas the Langmuir constant qm was found to be 1.85, 2.41, 3.54, and 2.28 mg/g at 25–60 °C. Furthermore, adsorption follows a pseudo-second-order rate constant of (3.08, 3.24, 3.24, and 13) g/mg/min under identical temperature conditions, as opposed to a first-order rate constant of 4, 3, 2.6, and 2. Hg2+, NH4+, Cl−, Br−, NO3−, SO42−, Na+, K+, H2S, and CH3SH were all extracted from wastewater by this application. [ABSTRACT FROM AUTHOR]

This study investigates the batch adsorption of eosin-B (EB) from wastewater onto the commercial anion exchange membrane (AEM) DF-120 at a temperature of 25 °C. The detailed influence of various operational factors on the percentage removal of EB is outlined. The EB removal percentage from wastewater demonstrates an increase with the mass of AEM DF-120 and contact duration. At the same time, the percentage removal of it decreases with the rise in temperature and concentration. Results from the adsorption kinetics studies reveals that EB adsorption conforms to pseudo second order (PSO) model, having a correlation coefficient (R² ) value of 0.999. The adsorption isotherm analysis indicates that EB adsorption aligns with the Langmuir isotherm as the value of R² approaches unity. Furthermore, the measured mean adsorption energy (E = 0.68 KJmol−1) suggests that this is a physical adsorption process. Thermodynamic assessments of adsorption reveal its exothermic nature, supported by the value of enthalpy (ΔH° = −56.09 KJ mol−1). Additionally, Gibb’s free energy (ΔG°) value signifies that the process is feasible. The regeneration of the commercial AEM DF-120B was also revealed. [ABSTRACT FROM AUTHOR]

Use of nitrogen (N) fertilizers is gaining popularity to meet crop nutrient requirement for sustaining the food security of the increasing global population. However, improper management of N fertilizers in acid soils causes leaching and surface runoff because of excessive rainfalls and poor N retention in the tropics in particular. This results in N pollution in water bodies (also known as eutrophication), which degrades water quality to the detriment of aquatic ecosystems near farms. Thus, there is a need for using inorganic soil amendments such as Calciprill and sodium silicate to improve soil N adsorption because of the alkalinity and ability of these amendments to retain N for mitigating excessive N contamination in water bodies. To this end, this N sorption study was conducted to determine the effects of Calciprill and sodium silicate on ammonium (NH4+) adsorption and desorption in an acid soil (Bekenu series, Typic Paleudults). The soil was co-applied with different rates of Calciprill (80 %, 90 %, and 100 % Ca saturations) and sodium silicate (90, 105, 120, 135, and 150 kg ha-1), followed by the NH4+ adsorption capacity determination through the additions of NH4+ isonormal solutions at the five concentrations (0, 25, 50, 75, and 100 mg L-1) to establish a linear relationship between the amount of NH4+ absorbed (qe) and the amount of NH4+ left in the solution (Ce) after 24 h of equilibration. Apart from the soil only without any amendment (C0S0), there were another two additional treatments where the soil was added with Calciprill (100 % Ca saturation) (C3) and sodium silicate only (150 kg ha-1) (S5) to determine their respectively effects on N sorption. The collected data were fitted to the Langmuir and Freundlich isotherms. Thereafter, NH4+ desorption was determined using the same soil samples added with 2 mol dm-3. Compared with the soil without any amendment (C0S0), the Calcirpill alone (C3) and the combined use of Calciprill and sodium silicate significantly increased NH4+ adsorption at the NH4+ addition of 250 mg L-1, suggesting that Calciprill is the amendment which dominantly increases NH4+ adsorption and the effects of amendments are more pronounced at the lower soil NH4+ concentration. The results also revealed that the NH4+ adsorption in the soils following the co-application of Calciprill and sodium silicate followed the assumption of Freundlich isotherm. Regardless of the NH4+ concentration used, the effects of Calciprill and sodium silicate on the NH4+ desorption remain unclear, which could be because of the ability of sodium silicate to stabilize the soil structure. This stabilization reaction might have impeded the dissolution of Calciprill and temporarily fixed the absorbed NH4+. These findings suggest that it is possible to use the amendments to amend NH4+ sorption in Bekenu series for mitigating NH4+ leaching and runoff to prevent eutrophication. [ABSTRACT FROM AUTHOR]

The corrosion inhibition performance of L(-)- Cystine on copper alloy immersed in 2 M HNO3 solution is investigated using weight loss, potentiodynamic polarisation, electrochemical impedance spectroscopy, and scanning electron microscopy. Potentiodynamic polarization measurements confirmed that L(-)-Cystine behaved as mixed-type inhibitor. The highest corrosion inhibition efficiency was 98.99% at 298 K and decreased with increasing temperature. The Nyquist plots displayed an increase in the capacitive loops with increasing the concentration of the inhibitor. The mechanism of inhibition obeys Langmuir isotherm. SEM images confirm the adsorption of L(-)-Cystine on the surface of the cooper alloy [ABSTRACT FROM AUTHOR]

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The present study utilized zinc-tin nanoflowers (ZT-NFs) in a batch adsorption treatment process to effectively remove cadmium from synthetic wastewater. The batch adsorption strategy was optimized using the univariate approach to enhance the efficiency of the adsorption process. The dominant parameters examined in the optimization experiments were pH/volume of buffer solution, nanoflower amount, and sample agitation type/period. After determining the optimal batch adsorption conditions, equilibrium studies were performed by adding cadmium to synthetic wastewater at concentrations in the range of 1.0 – 40 mg/L. The quantification accuracy for cadmium was improved by developing the calibration plot with spiked sample matrix. The equilibrium data were subjected to mathematical modelling utilizing the Langmuir adsorption isotherm model. The calculated isotherm constants indicated a well-fitted isotherm model to the experimental data. The reported ZT-NFs-based adsorptive removal strategy was effectively employed to remove cadmium from synthetic wastewater. [ABSTRACT FROM AUTHOR]

The stem extract of Solanum Lycopersicum prepared using the methanol extraction method has been investigated as an environment-friendly inhibitor for low-carbon steel in monoprotic(1N HCl) and diprotic(1N H2SO4) solvents and characterized with FT-IR. A maximal inhibition efficiency of 81.8% in 1 N Hydrochloric acid and 92.92% in 1 N Sulfuric acid is assessed under a certain set of conditions of inhibitor concentration and temperature using weight loss, electrochemical impedance spectroscopy and potentiodynamic polarization. The results present Solanum Lycopersicum extract as a mixed-type inhibitor that predominantly influences the cathodic reaction and followed the Langmuir adsorption isotherm. Reduction in the value of average roughness (Ra)of the surface from 217 nm to 55 nm (in 1 N HCl) and 139.6 nm to 28 nm (in 1 N H2SO4) was observed with AFM after the application of the inhibitor which confirms the formation of a protective membrane and provides green inhibition on the low-carbon steel/solution interface. [ABSTRACT FROM AUTHOR]

The Langmuir isotherm, originally developed to study the adsorption of gases, has been modified in this research to investigate the adsorption of solutes in the solution phase. The modification considers the adsorption of solvent molecules and the interactions between adsorbed particles and the species in the solution. Three equations have been obtained to calculate the contribution of these additional effects on the Gibbs free energy, enthalpy, and entropy of solute adsorption based on the new isotherm. The study evaluated the efficiency of the new isotherm in the adsorption of some metal ions in an aqueous solution and found that it is more accurate than the Langmuir isotherm and provides a deeper insight into the adsorption process in the solution phase. Practitioner Points: Modification of the Langmuir isotherm for adsorption in solution.Comparison of the efficiency of the Langmuir and modified Langmuir isotherms.Accurate determination of ∆Hadso$$ \Delta {H}_{ads}^o $$ and ∆Sadso$$ \Delta {S}_{ads}^o $$ for Pb(II), Cd(II), and Ni(II) adsorption. [ABSTRACT FROM AUTHOR]

In this article, FeNi3@MnO2 core–shell nanostructure has been used for the first time to remove Pb(II) and Cd(II) from aqueous solutions by adsorption. The MnO2-coated FeNi3 magnetic nanoparticles were synthesized by the hydrothermal method and characterized by various analytic methods such as X-ray diffraction, Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscope, transmission electron microscope, and atomic absorption spectrometry. Adsorption parameters such as pH, contact time, adsorbent amount, and initial concentration of metal ions were investigated and optimized. FTIR Spectrum of the nanostructure was used to analyze the adsorption mechanism. FeNi3@MnO2 adsorbent was shown to follow the Langmuir adsorption isotherm and the pseudo-second-order kinetic model. The thermodynamics of adsorption confirmed an endothermic and spontaneous process. The calculated maximum adsorption capacities of the adsorbent for Pb(II) and Cd(II) were 129.2 mg g−1 and 127.8 mg g−1 at room temperature, which confirmed a good adsorption performance, especially for Cd(II). The adsorbent had a good removal efficiency of more than 99% for both metal ions, which was achieved in only 20 minutes. [ABSTRACT FROM AUTHOR]

Phosphate sorption on rendzina soil was studied by P-32 heterogeneous isotopic exchange under a steady-state. There are two types of sorbed phosphate, namely strongly and weakly bonded phosphate, the latter being able to exchange with phosphate (H232PO4−) ions in the soil solution. The experimental kinetic data was not fitted by the one exponential kinetic model. Starting from this observation, a new kinetic model is established by assuming two types of weakly bonded phosphate, which take part in the two parallel exchange processes. A biexponential kinetic equation is obtained, which fits the experimental data much better than the one exponential equation. [ABSTRACT FROM AUTHOR]

Wastewater discharges from industrial processes typically include elevated concentrations of contaminants, which largely consist of potentially harmful chemicals such as heavy metals. These contaminants are characterized by their slow rate of decomposition. Hence, the removal of these metallic ions from effluents poses a challenge. Among different treatments, the adsorption approach has considerable potential due to its ability to effectively eliminate both soluble and insoluble pollutants from effluent, even at lower levels of concentration. Of various wastes, fly ash (FA) material has been the subject of attention because it is abundant, has favorable qualities, and contains a high percentage of minerals. This review investigates multiple facets, with a specific focus on the application of FA, an industrial byproduct, as an adsorbent in removing heavy metals. A comprehensive examination was conducted on a range of concerns pertaining to the pollution caused by metallic ions, including the underlying causes, levels of contamination, health implications of heavy metals, and removal methods. Multiple factors were found to affect the adsorption process. Of all the factors, the pH value considerably influences the elimination of heavy metals. An acidic pH range of 2.5–4.5 was found to be optimal for achieving the highest possible elimination of As(V), Cu(II), Hg(II), and Cr(VI). The latter elimination rate reached 89% at the optimal pH level. Most heavy metals' adsorption isotherms conformed to the Langmuir or Freundlich models, while the pseudo-second-order kinetics provided a satisfactory match for their removal. Using a raw FA, adsorption capacities were achieved in the removal of metallic ions, Ni(II), Pb(II), and Cr(VI), that ranged from 14.0 to 23.9 mg g−1. Meanwhile, the FA-zeolite showed a remarkable capacity to adsorb ions Mn(II), Ni(II), Cd(II), Cu(II), and Pb(II), with values ranging from about 31 to 66 mg g−1. The cost analysis showed that the treatment of FA is economically advantageous and may result in significant cost reductions in comparison to commercial adsorbents. In summary, FA is an inexpensive waste material with potential for water treatment applications and several other purposes due to its excellent chemical and mineralogical composition. [ABSTRACT FROM AUTHOR]

This work focuses on the characterization of five palygorskite clays from the Brazilian state of Piaui and their feasibility as eco-friendly adsorbents for the removal of Fe3+ ions from aqueous solutions. For characterization, we applied the techniques of X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS), size distribution measurements, density measurement by He pycnometry, superconducting quantum interference device (SQUID) magnetometry, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA/DTA), zeta potential measurement, hydrophobicity determination by contact angle, Brunauer–Emmett–Teller surface area analysis (BET technique) and atomic force microscopy (AFM). Batch experiments were performed in function of process parameters such as contact time and initial concentration of Fe3+. The natural palygorskites (Palys) had excellent performance for the removal of Fe3+ from aqueous solutions by adsorption (around 60 mg/g), and the Langmuir is supposedly the best model fitted the experimental data. [ABSTRACT FROM AUTHOR]

This work focuses on the characterization of five palygorskite clays from the Brazilian state of Piaui and their feasibility as eco-friendly adsorbents for the removal of Fe3+ ions from aqueous solutions. For characterization, we applied the techniques of X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS), size distribution measurements, density measurement by He pycnometry, superconducting quantum interference device (SQUID) magnetometry, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA/DTA), zeta potential measurement, hydrophobicity determination by contact angle, Brunauer–Emmett–Teller surface area analysis (BET technique) and atomic force microscopy (AFM). Batch experiments were performed in function of process parameters such as contact time and initial concentration of Fe3+. The natural palygorskites (Palys) had excellent performance for the removal of Fe3+ from aqueous solutions by adsorption (around 60 mg/g), and the Langmuir is supposedly the best model fitted the experimental data.

Abstract Aluminum corrosion inhibitors “{[CuI (CN)2(phen) CuII (CN)2(phen)]5H2O},(MOF1) and {[CuI(CN)2(phen)CuII(CN)2(phen)]5H2O}@TiO2 (MOF1@TiO2) were studied in one molar HCl solution”. The ML results for three different temperatures (25–45 °C) were compared with the results of PDP and EIS analyses. The adsorption of inhibitors on Al surfaces has been calculated and discussed by a Langmuir isotherm. The inhibitors that were created showed great effectiveness, with a noticeable increase in their inhibitory efficiency as the dosage was raised and the temperature was lowered. Inhibition efficiency each amounted to 88.6%, 84.5% at 400 ppm and 25 °C for MOF1@TiO2 and MOF1, respectively. Analyzing the polarization curves of synthesized inhibitors revealed that they were mixed-type inhibitors. Al was found to be surface inhibited when coated with a thin film of inhibitors, and “Al's surface morphology was assessed by different techniques such as scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and atomic force microscope (AFM)”. “Theoretical models like quantum chemical and molecular dynamics simulation authenticated the experimental observation”. The MOFs exhibit exceptional corrosion resistance against Al when exposed to acidic environments, according to several tests.

The effective treatment of wastewater generated from households, communities, and industries is vital for preserving our environment. Chemical treatment, which involves adding coagulant chemicals directly into the wastewater, is the most popular treatment method. However, due to its high operating costs and the issue of secondary contamination, there is a need for an effective method to address these issues. In this study, we investigated the electrocoagulation (EC) system, which is currently undergoing a revival in research due to its promising features, such as low system and operating costs and its environmentally friendly process. We developed two-dimensional unsteady mathematical models supported by Langmuir isotherm theory to elucidate the underlying physics of the aluminum-based EC process and to understand key control parameters. The developed model was used to analyze the effects of EC cell geometry and operating conditions on the local distribution of intermediate ionic species and their impact on the adsorption behaviors of EC-generated coagulants on arsenic pollutants in the wastewater for the first time. It was found that a higher removal rate was achieved as the EC treatment time and current intensity increased, while the cell gap and inflow rate decreased. Applying the current-off condition during the EC process was found to be an efficient method for increasing the removal rate with less consumption of electrical energy. [ABSTRACT FROM AUTHOR]

The adsorption of iron (III) from sulfuric acid solutions on a strongly acidic cation-exchange resin Dowex G-26 (H) has been studied. The factors influencing the adsorption of iron (III) have been investigated: solution pH, contact duration, adsorbent dose, initial concentration of iron (III) in solution. The obtained results show that Dowex G-26 (H) resin has a high exchange capacity for iron (III) ions from sulfuric acid solutions. Complete adsorption of iron (III) was achieved at pH>2 (99%). Based on the experimental results, Langmuir and Freindlich adsorption isotherms have been constructed. Both isotherms fully describe the adsorption of iron(III) by the Dowex G-26 adsorbent. However, a comparison of the Langmuir correlation coefficient (R²=0.9098) with respect to Freundlich (R²=0.9915) shows that the Freundlich isotherm provides a better fit than the Langmuir isotherm. Quantitative and quantitative sorption properties of Dowex G-26 (H) relative to iron (III) have been investigated using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The maximum adsorption capacity (qm) for iron (III) was 166 mg/g at 25℃. It has been shown that Dowex G-26(H) can be recommended as an adsorbent for sorption of Fe(III) from acidic solutions. [ABSTRACT FROM AUTHOR]

The FeZnO (iron zinc bimetallic oxide) was synthesised using the ultrasound-assisted method and further converted into FeZnOAC (iron zinc bimetallic oxide-doped activated carbon) by treating it with activated carbon. As developed FeZnOAC is effectively used for the adsorption of Fuchsine dye from an aqueous dye solution. A 200 mg of FeZnOAC was sufficient for the rapid removal of Fuchsine (>97.64%) dye. The kinetic adsorption data is well fitted with a pseudo-second-order model. The Langmuir isothermal model shows a high regression coefficient (R2) than the Freundlich with a Qmax of 333.33 mg g−1. The dye adsorption at varying temperatures (i.e. 298–318 K) was based on a multi-layered statistical physics model. The n value (n < 0.5) obtained from the model indicates that the Fuchsine dye adsorbed on the surface of FeZnOAC is parallel adsorption. It shows that the dye molecules' adsorptive orientations are dependent on the temperature and nature of the system. The FeZnOAC is proven to be a potential adsorbent for the removal of Fuchsine due to the availability of more adsorption sites. Interestingly, FeZnOAC is used for regeneration studies up to five cycles with a maximum adsorption capacity of 97.4%. The as-synthesised FeZnOAC has been successfully applied to remove Fuchsine dye from industrial wastewater, resulting in an alternative candidate for commercialisation. [ABSTRACT FROM AUTHOR]

Ultisols and Oxisols are the two dominant soils in the tropics. These soils are mostly infertile and have low cation exchange capacity because of their low pH (4 to 5). They are composed of kaolinite and sesquioxides which are prone to potassium (K) leaching. To make these soils arable, liming and fertilization are required. Nevertheless, this conventional practice alone does not mitigate K availability in such soils because of their low pH buffering capacity and low K adsorption capacity. The alkalinity of sago (Metroxylon sagu) bark ash and charcoal and the deprotonation of charcoal’s functional groups by the carbonates and oxides of sago bark ash have potential benefits. Due to these characteristics of sago bark ash and charcoal, they could be utilized to improve soil pH buffering capacity and K adsorption capacity to prevent the leaching of K and the pollution of water bodies. Moreover, the use of charcoal and sago bark ash to amend soils is a good way of utilizing agro-wastes sustainably. Thus, the objective of this study was to determine the effects of amending tropical acid soils with charcoal and sago bark on K sorption and pH buffering capacity. The treatments evaluated were: (i) 300 g soil only, (ii) 250 g charcoal only, (iii) 250 g sago bark ash only, (iv) 300 g soil + 15.42 g charcoal, (v) 300 g soil + 7.71 g sago bark ash, and (vi) 300 g soil + 15.42 g charcoal + 7.71 g sago bark ash. Langmuir bonding energy constant (KL), Maximum K buffering capacity (MBC), and maximum adsorption capacity (qmax) of the soil with charcoal and sago bark ash were higher than that of soil alone. However, desorption of K was not significantly affected after application of the amendments. On the other hand, the combined use of charcoal and sago bark ash improved the soil’s pH buffering capacity in comparison to the untreated soil because of the inherently high CEC and alkalinity of these amendments. Therefore, this intervention could contribute to improving K fertilizer use and prevent environmental pollution and economical loss to farmers. [ABSTRACT FROM AUTHOR]

The enzymatic hydrolysis of lignocellulosic biomass has become attractive for obtaining ethanol. Therefore, optimizing its conditions and revealing the main influencing factors are essential for an effective design. In this sense, this study evaluated the influence of cellulose conversion on the Langmuir isotherm parameters in cellulase adsorption on sugarcane bagasse pretreated by hydrothermal and organosolv methods. The adsorption isotherm assays were performed with commercial cellulase from Trichoderma reesei in Erlenmeyer flasks stirred at 150 rpm and 50 °C. Isotherms were determined for enzymatic hydrolysis substrate samples of hydrothermal bagasse (HB) and organosolv bagasse (OB) at 0, 1, 6, and 18 h, respectively. The Langmuir model represented well the experimental data for the cellulose–cellulase system. The study of cellulase adsorption on HB and OB demonstrated that the maximum adsorption capacity (Emax) decreased during the reaction. From 0 to 18 h of hydrolysis, the value of Emax decreased from 37 ± 3 to 23 ± 2 mg cellulase/g HB and from 29 ± 1 to 25 ± 2 mg cellulase/g OB. Therefore, the adsorption of cellulase on a substrate varied during hydrolysis and its representation was expressed by an empirical equation related to the cellulose conversion and the Langmuir parameters. [ABSTRACT FROM AUTHOR]

The ability to repurpose adsorbent was critical for making the sewage treatment system both premium and environmentally beneficial. Toxic metals ions [Pb(II), Cr(II), and Cd(II)] were removed from effluent discharge using Fe3O4/ZnO nanoparticles as sorbent materials. Chemical affinity, zero potentials, XRD, FTIR, and TEM were used to explore the structural and interfaces adsorption process of Fe3O4/ZnO composite in this study. Experiments on absorption, desorption, and recycling were performed. The findings demonstrate that perhaps the toxic metals substituted for H in the Fe–O–H structure and formed the Zn–O–Me structure, implying that metal elimination was accomplished through ion exchange. Cd(II), Pb(II), and Cr(IV) had 99.81%, 99.76%, 98.1%, respectively,adsorptive degradation efficiency. The Langmuir model was shown to be the best fit for describing the absorption on the surface of Fe3O4/ZnO nanoparticles based on the stability data processing. The kinetic parameters of toxic metal ions on the surface of Fe3O4/ZnO composites were relatively similar to the pseudo-second-order concept, according to the kinetics investigations. The trials proved that reprocessing the Fe3O4/ZnO sorbent extracted from water by a magnetic material was a viable option for removing pollutants in an environmentally acceptable and effective manner. [ABSTRACT FROM AUTHOR]

The recycling of waste materials in wastewater decontamination has been an attractive discipline in zero discharge and energy recovery. Biochar/zeolite nanocomposite has been successfully synthesized as a cheap and eco-friendly material from a solid fraction obtained from the thermos-catalytic conversion of green pea agriculture waste (Pisum sativum). A dark-whitish solid was obtained from thermal pyrolysis at 450 °C with a heating rate of 27 °C/min for 15 min that was further subjected to alkaline chemical activation. The synthesized composites have been examined using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), transmission emission microscopy (TEM), and Brunauer-Emmet-Teller (BET) analyses. The successful preparation of biochar/zeolite nanocomposite was evident from characterization results with an average particle size of 30–40 nm with a high surface area of 15.3 m2/g. The material was evaluated as an eco-friendly adsorbent for decolorization of both cationic methylene blue dye (MB) and Congo red anionic dye (CR) using the batch technique. The influence of dosage, pH, temperature, initial dye concentration, and contact time were studied against the dye adsorption process. It was indicated that the material recorded maximum dye decolorization efficiencies of 87.5% at pH of 12 and 84.1% at pH of 2 for MB and CR, respectively. The optimum material dosage and contact time for dye decolorization were 5 g/l and 60 min, respectively. Thermodynamic parameters were calculated from the sorption process and revealed a negative charge of Gibbs free energy ( Δ G o ) an indication of spontaneity and thermodynamic favorability. Positive enthalpy and entropy demonstrated the endothermic behavior and the disorderliness. Equilibrium adsorption results best fitted to the Langmuir isotherm model, while MB and CR adsorption kinetics were pseudo-second-order reactions. [ABSTRACT FROM AUTHOR]

In this article, research has been conducted on obtaining an eco-friendly inhibitor and its application in practice. The source of the green inhibitor is the Salsola oppositifolia plant, from which the method of obtaining the green inhibitor extract is studied. The obtained extract is studied as a green inhibitor in 0.5 M HCl solution for corrosion protection of carbon steel structures. In determining the efficacy of a green inhibitor derived from the Salsola oppositifolia plant, practical experiments have been performed at two different temperatures (298 K and 313 K) and at different concentrations (200 mg/L, 400 mg/L, 600 mg/L, and 1000 mg/L). Adsorption of green inhibitor on steel surface has been studied using Langmuir and Temkin isotherms. The effect of temperature and concentration on the corrosion rate is also studied. The gravimetric method is used to determine the effectiveness of the green inhibitor and it is found that its maximum concentration is 91.86%. The mechanism of action of the steel surface and a post-experimental steel sample are studied by scanning electron microscope analysis. Salsola oppositifolia extract is a good green inhibitor due to the presence of hetero atomic organic compounds in the main component. [ABSTRACT FROM AUTHOR]

The L-cysteine-functionalized silica (SG-Cys−Na+) matrix was effectively loaded with silver (I) ions using the batch sorption technique. Optimal Ag(I) loading into SG-Cys−Na+ reached 98% at pHi = 6, 80 rpm, 1 mg L−1, and a temperature of 55 °C. The Langmuir isotherm was found to be suitable for Ag(I) binding onto SG-Cys−Na+ active sites, forming a homogeneous monolayer (R2 = 0.999), as confirmed by FTIR spectroscopy. XRD analysis indicated matrix stability and the absence of Ag2O and Ag(0) phases, observed from diffraction peaks. The pseudo-second-order model (R2 > 0.999) suggested chemisorption-controlled adsorption, involving chemical bonding between silver ions and SG-Cys−Na+ surface. Thermodynamic parameters were calculated, indicating higher initial concentrations leading to increased equilibrium constants, negative ΔG values, positive ΔS values, and negative ΔH. This study aimed to explore silver ion saturation on silica surfaces and the underlying association mechanisms. The capability to capture and load silver (I) ions onto functionalized silica gel materials holds promise for environmental and water purification applications. [ABSTRACT FROM AUTHOR]

This study deals with lipase immobilization on micro- and mesoporous silica-based materials. The effects of the type of support (silica MCM-41, zeolite HZSM-5 (SAR 25), zeolite HZSM-5 (SAR 280), and the silica-aluminas Siral 10, Siral 20, and Siral 40) were investigated on the immobilization of lipase B from Candida antarctica (CALB) and lipase from Rhizomucor miehei (RML). The supports that allowed the highest immobilization efficiencies for the CALB were Siral 40 (91.4%), HZSM-5 (SAR 280) (90.6%), and MCM-41 (89.4%). Siral 20 allowed the highest immobilization efficiency for RML (97.6%), followed by HZSM-5 (SAR 25) (77.1%) and HZSM-5 (SAR 280) (62.7%). The effect of protein concentration on lipase immobilization was investigated, and the results adjusted well on the Langmuir isotherm model (R2 > 0.9). The maximum protein adsorption capacity of the support determined by the Langmuir model was equal to 10.64 and 20.97 mgprotein gsupport−1 for CALB and RML, respectively. The effects of pH (pH 7.0 and pH 11.0) and phosphate buffer solution concentration (5 and 100 mmol L−1) were also investigated on lipase immobilization. The immobilization efficiency for both lipases was similar for the different pH values. The use of 100 mmol L−1 phosphate buffer decreased the lipase immobilization efficiency. The biocatalysts (CALB-Siral 40 and RML-Siral 20) were tested in the ethyl oleate synthesis. The conversion of 61.7% was obtained at 60 °C in the reaction catalyzed by CALB-Siral 40. Both heterogeneous biocatalysts showed increased thermal stability compared with their free form. Finally, the reuse of the biocatalysts was studied. CALB-Siral 40 and RML-Siral 20 maintained about 30% of the initial conversion after 3 batches of ethyl oleate synthesis. Silica-aluminas (Siral 20 and 40) proved to be a support that allowed a high efficiency of immobilization of lipases and activity for esterification reaction. [ABSTRACT FROM AUTHOR]

This study used a quaternary surfactant, N‐(4‐Chloromethylbenzyl)‐N, N‐dimethyldodecan‐1‐aminium chloride (CMBDAC), as an excellent corrosion inhibitor of C1018 carbon steel (C1018 CS) in harsh 15 % HCl acidizing condition. CMBDAC was synthesized with an excellent yield and characterized by NMR, FTIR, and TGA. Gravimetric weight loss (WL), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) studies were employed to measure the efficacy of CMBDAC. At a relatively low concentration of 15 ppm, CMBDAC surpassed 90 % inhibition efficiency, with a maximum inhibition efficiency of 99.25 % being reached just for 50 ppm of CMBDAC. The inhibitor showed an efficacy of 96.16 % even at a temperature of 60 °C via the WL technique, showing potential to be used as a high‐temperature corrosion inhibitor. The adsorption isotherm study revealed that CMBDAC followed Langmuir adsorption isotherm. The Gibbs free energy of adsorption (ΔGads∘) ${{\Delta G}_{ads}^{^\circ{}})}$ was calculated to be −40.43 kJ mol−1, indicating that CMBDAC was adsorbed via chemisorption. A very high value (1.68×105 L mol−1) of equilibrium constant (Kads ${{K}_{ads}}$) suggested very strong adsorption of the inhibitor. PDP study disclosed that CMBDAC acted as a mixed‐type inhibitor. SEM‐EDX study demonstrated the adsorption of CMBDAC on the C1018 surface. Different DFT‐optimized parameters have been discussed in detail to support the superb inhibitory action indicated by CMBDAC. [ABSTRACT FROM AUTHOR]

The current research was designed to use the Mangifera indica (mango) leaves (MIL) powder for eradication of eosin yellow (EY) dye from an aqueous solution at 25°C. Adsorption of eosin yellow (EY) onto MIL powder was investigated by X-ray diffraction. The percentage adsorption of EY was increased with contact time, mass of MIL powder (adsorbent) and temperature while decreased with EY initial concentration. Several non-linear isotherm models were applied in order to investigate EY adsorption onto MIL powder and attained results exhibited that adsorption of EY obeyed non-linear Langmuir isotherm model. Determined maximum theoretical adsorption capacity was 39.67 mg/g. In addition, EY adsorption onto MIL powder was physical adsorption process. Adsorption kinetics of EY adsorption was illustrated by applying non-linear pseudo-first-order and pseudo-second-order models. Attained results exhibited that non-linear pseudo-second-order model fitted to EY adsorption. Thermodynamics investigations represented the endothermic and spontaneous nature of EY adsorption process. The desorption of EY from MIL powder was also studied. [ABSTRACT FROM AUTHOR]

The loss of metals due to corrosion can be prevented using green inhibitors. Using natural and eco-friendly plant products is futuristic, preventing the environment from toxic and harmful chemicals. The present study aimed to investigate whole beetroot (BR, Beta vulgaris) for its anti-corrosion behaviour by galvanostatic polarization and electrochemical impedance techniques at a temperature between 298 K-328 K. The temperature study would help in proposing BR's adsorption mechanism on metal surfaces. The maximum inhibition efficiency of 94% at 298 K for 5% BR was observed, whereas a minimum of 75% was obtained for 1% BR at 328 K. It was found to be a mixed-type inhibitor that followed Langmuir isotherm. From thermodynamic studies, ΔGoads was found to be -13.64 kJ/mol, which revealed that BR adsorbed physically on the surface of mild steel. Rct values increased while Cdl values decreased on exposure of metal surface with BR extract. The scanning electron micrographs (SEM) and atomic force micrographs (AFM) witnessed the formation of a protective layer on the mild steel surface, which served as a barrier between the metal and corrosive medium. The present study provides a remedy for the financial and structural losses due to metal corrosion in an acidic medium. [ABSTRACT FROM AUTHOR]

Presence of colors, organic surface finishing agents and surfactants in textile industry effluent makes it highly detrimental for surrounding environment. Hence the effluent from textile industry needs treatment for removal of these colors, organic and inorganic components before its disposal. Hence applicability of low cost and environmental friendly biosorbents, Azospirillium biofertilizer and Rhizobium biofertilizer were investigated for removal of Congo red dye. Batch experimentation was carried out to check operating parameters like, temperature, dose of adsorbent, pH, agitation speed, contact time and initial concentration. The biosorption capacity for Congo red dye was 67.114 and 101.01 mg/g, for Azospirillium biofertilizer and Rhizobium biofertilizer, respectively at optimized parameters. RL factor was 0.558 and 0.568 for Azospirillium biofertilizer and Rhizobium biofertilizer. The data showed combination of interaction-based separation through better fitting of Langmuir isotherm compared to Freundlich. Its separation is well described by Pseudo-second order and intraparticle diffusion model. Adsorption was favorable at lower temperature suggesting exothermic and spontaneous nature. Reusability for Azospirillium biofertilizer and Rhizobium biofertilizer was checked for 25 mg/land. While the biological nature of Azospirillium and Rhizobium biofertilizer makes removal of Congo red dye environmentally benign. [ABSTRACT FROM AUTHOR]