In the present study, a composite hydrogel adsorbent (ALG@CNCs/CEGSL) was fabricated using nanocellulose extracted from kenaf fiber and calcined eggshells. Its adsorption properties were successfully evaluated for the removal of Indigo Carmine (IC) dye from an aqueous solution. the prepared adsorbent was characterized using FE-SEM, XRD, TGA, and BET techniques. The specific surface area and average pore diameter were measured as 3.534 m²/g and 5.990 Å, respectively. The effects of solution pH, contact time, adsorbent dosage, and initial dye concentration were investigated. The results indicated that IC adsorption onto ALG@CNCs/CEGSL is strongly dependent on the solution’s pH. Kinetic data were well fitted by the pseudo-second-order model (R² > 0.999). The maximum adsorption capacity of ALG@CNCs/CEGSL was 563.812 mg g− 1, achieving an adsorption efficiency of 94.72

Industrial effluents from metallurgy, chemicals, and other sectors are major releasers of heavy metals polluting the environment. Within this study, chitosan (CS) and nanocellulose (NCs) were extracted from fish scales and coconut fiber, respectively, and co-precipitated in sodium alginate (ALG) solution to produce a biocomposite hydrogel (CS@NCs/ALG). The adsorptive efficiency of the new composite was determined for detoxification of 2 heavy metals (Hg2+, Zn2+) from aqueous solution. The main physicochemical properties of CS@NCs/ALG were characterized by application of spectroscopy (FTIR, XRD, SEM-EDX), with analytical methods including BET, TGA, pHPZC. The results show that CS@NCs/ALG exhibits a heterogenous and mesoporous structure with surface functional groups including -OH, -NH2, and -COOH groups. Removal tests indicated that the adsorption of these metals was strongly influenced by solution pH. Modelling of the adsorption results indicated best fits to the pseudo-second order kinetic and Langmuir isotherm models. High adsorption capacities (402.89 and 500.48 mg g− 1) were obtained for Hg2+ and Zn2+. Thermodynamic analysis revealed that the adsorption of both ions was thermodynamically favorable, spontaneous, and accompanied by decreased randomness. These findings demonstrate that the hydrogel composite has high adsorption potential and can be effectively applied for bivalent heavy metal detoxification from contaminated aquatic systems.

In this study, a mineral-organic composite adsorbent (Montm@GHBC) was synthesized using Montmorillonite clay and biochar derived from Gossypium hirsutum L., the world's most widely cultivated cotton species. The composite was prepared via an impregnation-carbonization method, and its adsorptive properties were evaluated for the removal of Malachite Green (MG) dye from aqueous solutions. The fabricated adsorbent was characterized using X-ray diffraction, Brunauer–Emmett–Teller (BET) analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy (FTIR). BET analysis revealed a specific surface area of 14.41 m2/g, primarily composed of mesopores, with a T-micro volume of 0.03 cm3/g and a BJH pore diameter of 61.11 Å. FTIR analysis identified functional groups such as –OH and –COOH, which are responsible for interactions between dye molecules and the composite. Under optimal conditions (natural pH, an adsorbent dose of 0.05 g, a contact time of 30 min, and room temperature), the maximum monolayer adsorption capacity was 110.7 mg/g, with an adsorption efficiency of 87.07

The synthesis and characterization of a Gossypium hirsutum stalk fiber extract coated pozzolan powder (POZ1) are described in this work as a promising adsorbent material for the removal of Methylene blue and Rhodamine 6G dyes from aqueous solutions. According to X-ray powder diffraction (XRD), the main mineral phases of raw pozzolan were augite, bytownite, forsterite, gandilite, nepheline, and quartz. Functional groups on the surface of the material were characterized by FTIR spectroscopy, while its thermal stability was measured by thermal gravimetric analysis TGA. The experimental results demonstrated that both cationic dyes were effectively adsorbed by POZ1 under the ideal conditions of 30 min of contact time, without pH adjustment, 2 g/L of adsorbent, and 100 mg/L of initial dye concentration. The pseudo-second-order model, which highlights chemisorption as the primary mechanism behind the removal of MB and Rh6G from POZ1, provided the best description of the adsorption process. The isotherm study's nonlinear modeling analysis showed that the Langmuir model offered the best match, with maximum adsorption capacities on POZ1 of 53.24 and 30.63 mg/g for the elimination of MB and Rh6G, respectively. From the results of thermodynamic studies, it was found that the adsorption process of MB and Rh6G onto POZ1 occurred by exothermic and non-spontaneous processes. According to the results, Gossypium hirsutum stalk fiber extract coated pozzolan can be considered a low-cost and environmentally acceptable adsorbent for the treatment of cationic dyes contaminated water.

Compatible and environmentally clean activated carbon material was prepared via physicochemical method and used for harmful pollutant removal from aqueous solution. The performance of the pristine cottonseed cakes and its activated carbon was examined towards copper ions removal as targeted pollutant through adsorption process. The physicochemical properties of adsorbents were evaluated by numerous experimental techniques such as Fourier transform infra-red spectroscopy, Raman spectroscopy, scanning electron microscopy, the point of zero charge, iodine number and specific surface area. The effect of several key operational parameters such as contact time, adsorbent dose, pH, concentration and temperature were considered. Results of the adsorption tests exhibited significant sensitivity towards copper ions elimination at optimum conditions; the copper uptake capacity was enhanced with time up to equilibrium of 30 min with a minimum adsorbent dose of 0.1 g at alkaline pH of 10 for maximum concentration of 50 mg/L at room temperature (25 degrees C) and achieved appropriate adsorbed quantities of 51.56 mg/g for cottonseed cakes activated carbon (CCAC) and 48.5 mg/g for cottonseed cakes biosorbent (CCB). The values of point of zero charge are 2.63 and 6.32 for CCB and CCAC respectively which present high electrostatic attraction between positive charge of copper ions and negative charge of the surface at basic medium. Iodine number of 30.35 and 41.92 mg/g indicates random distribution of micropores. The specific surface area of CCAC (30.35 m2/g) is higher than the one of CCB (11.94 m2/g). FTIR shows good surface chemistry with various functional groups while Raman spectroscopy and SEM analyses revealed myriad morphological features and carbon phases (graphite and diamond). The adsorption of copper ions was described by pseudo second order kinetic model and favoured by Redlich Peterson isotherm corresponding to physisorption on CCB while the one CCAC involves chemical bonding and can be qualified as chemisorption mechanism as confirm by Delta H degrees of both materials.

Remediation of wastewater laden with dyes using optimized and less expensive techniques remains a challenge for environmental protection. In the current research work, alkaline activation approach was employed to derive a biosorbent from ditax fruit hulls (DS-FHB), and its sorption performance was tested on Methylene blue (MB) dye biosorption with optimizing adsorption parameters. Structural and chemical properties of DS-FHB including crystallinity, morphology, and surface functionality were analysed using XRD, SEM, FTIR technics, and pHPZC determination. Optimization of adsorption parameters using a centered composite design (CCD) from response surface methodology led to achieving a peak dye removal rate of 98.97 %. The optimal conditions were determined as DS-FHB mass of 0.23 g, pH 7.12, contact time 39.00 min, and initial MB concentration of 69.35 mg/L. The findings demonstrated a strong alignment with both the Langmuir isotherm and pseudo-second order kinetic model, suggesting their appropriateness in describing the adsorption process of MB onto DS-FHB. According to the Langmuir isotherm model, the sorption of MB dye onto DS-FHB occurred by monolayer formation with a maximum dye sorption capacity of 96.453 mg/g. Based on the structural and physico-chemical properties of DS-FHB biosorbent, and its adsoption applicability evaluated in the experimental conditions, detax derived-biosorbent can be proposed as a successful and effective low-cost biosorbent for removing cationic dyestuffs from aqueous solutions.

The present research work reports the ability of Hyphaene thebaica biosorbent (HTBS) and its biochar (HTBC) to adsorb methyl orange dye (MO) from aqueous solutions. The physicochemical characteristics of both adsorbents were determined through instrumental analyses, including scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), powder x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). MO adsorption experiments were conducted in a batch mode, by varying key adsorption parameters such as contact time, solution pH, adsorbent dosage and initial dye concentration. Based on the adjusted R2 and chi-square χ2 error values, it was observed that the Langmuir model (higher R2 and lower χ2) provided a better fit for MO adsorption on both adsorbents, while the adsorption kinetics followed a pseudo-second-order kinetic model. Under optimized conditions (pH 2, adsorbent dose of 0.03 g, initial dye concentration of 100 mg/L, 313 K, 270 rpm), the maximum Langmuir monolayer adsorption capacities for MO adsorption were found to be 195.15 mg/g for HTBS and 264.72 mg/g for HTBC, respectively. From the thermodynamic parameters, it can be deduced that MO adsorption on HTBS and HTBC was exothermic and spontaneous. The adsorption mechanism of MO dye onto both adsorbents can be attributed to various interactions, including electrostatic attraction, H-bonding, and π-π interaction. In light of these findings, Hyphaene thebaica shells derived biochar can be considered a cost-effective material with significant potential for the treatment of water contaminated with anionic dyes.

The present research work reports the preparation of Hyphaene thebaica derived-biochar (HTBC) and its applicability as eco-friendly and low-cost adsorbent for the removal of methyl orange (MO) dye. The main physicochemical characteristics of HTBC including its morphology, crystallinity and chemical function groups were determined through scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results showed that HTBC adsorbent was found to be constituted by heterogeneous surface with mesoporous having a surface area of 33.38 m2/g and pore diameter of 23.53 nm, and carboxylic and amine functional groups. Adsorption experiments were conducted using batch mode, by varying key adsorption parameters such as contact time, solution pH, adsorbent dosage and concentration. Adsorption isotherm modelling revealed that the Langmuir model (higher R2 and lower χ2) provided a better fit for MO adsorption onto HTBC, while the adsorption kinetics followed a pseudo-second-order kinetic model. Under optimized conditions (pH 2, HTBC dose of 0.03 g, initial dye concentration of 100 mg/L, 313 K, 270 rpm), the maximum Langmuir monolayer adsorption capacity for MO adsorption onto HTBC was found to be 264.922 mg/g. According the thermodynamic parameters, it can be deduced that MO adsorption on HTBC was exothermic and spontaneous. Adsorption mechanism can be attributed to various interactions, including electrostatic attraction, H-bonding, and π-π interaction. In light of these findings, biochar from Hyphaene thebaica shells can be considered a cost-effective and biodegradable adsorbent with significant potential for the treatment of water contaminated with anionic dyes.

The need for low-cost and efficient biosorbent materials for the decontamination of heavy metal polluted water is important to abate the toxic effects on humans and the environment. Therefore, the present research reports the adsorption of cadmium ions from an aqueous solution onto alkaline-treated coconut shell (Alk-CCS) powder as a low-cost potential biosorbent. The biosorbent was characterized by SEM, XRD, FTIR, and EDX. Batch biosorption experiments were used to determine the effect of pH, time, temperature, dosage, and concentration on biosorption. The isotherm, kinetic, and thermodynamic modelling of the process was performed. The optimum condition for the adsorption of Cd 2+ onto Alk-CCS was a pH of 6.4, adsorbent dosage of 0.2 g, and a contact time of 30 min. Moreover, a maximum monolayer adsorption capacity of 14.22 mg/g was obtained from the Langmuir model for Cd 2+ adsorption. From the nonlinear isotherm and kinetics analysis, cadmium ions adsorption on Alk-CCS followed the pseudo-second-order model involving chemical interactions, while the Sips model best fitted the isotherm evaluation. According to the satisfactory fitting to the Sips isotherm model, the adsorption could not be best fitted to the classical adsorption isotherm models such as Langmuir and Freundlich. Thermodynamic parameters indicated that the adsorption of Cd ions on Alk-CCS was feasible, spontaneous (negative value of ∆G °), and exothermic (negative value of ∆H °). Moreover, the nonlinear modelling showed that alkaline modified coconut shell powder is a viable and efficient adsorbent for the removal of cadmium ions from polluted water.

Current research work reports the investigation carried out on preparation and characterization of an alginate- Hyphaine thebaiba (ALG-HT) biocomposite adsorbent and, its ability to remove Cd(II), Cu(II), and Pb(II) ions from aqueous solution using a batch mode. Hyphaine thebaiba fruit shell was used as a precursor for preparation of ALG-HT biocomposite adsorbent. Physicochemical characteristics of synthetized biosorbent were characterized using XRD, SEM–EDX and FTIR analyses. Process parameters influencing metals ions adsorption such as adsorbent dosage, contact time, initial pH of solution, and initial concentration of heavy metal solutions were analysed. Based on R2 (value > 0.99) and nonlinear fit, Langmuir and pseudo-second-order models were suitable in the fitting of isotherm and kinetic data, respectively, indicating that chemisorption mechanism was involved. Langmuir maximum adsorption capacities of the biosorbent was for isotherm study (initial concentrations varying from 50 to 300 mg/L) were found to be in the range of 104.17 > 67.73 > 63.25 mg/g for Pb2+, Cu2+ and Cd2+, respectively. Highest adsorption capacity of ALG-HT was observed for the removal of lead ions. These results make it possible to propose ALG-HT composite as potential environmentally friendly and low-cost biosorbent for treatment of waters contaminated with bivalent heavy metals.

This study aimed at the adsorption of an anionic dye (amaranth) in a batch aqueous medium onto a local clay material collected in Cameroon. The prepared adsorbents were tested towards various adsorption parameters and the characterization was performed using X-ray Fluorescence (XRF), X-ray Diffraction (XRD),Fourier transform Infrared Spectroscopy (FTIR).The surface morphology of clay was revealed using scanning electron microscopy (SEM). The Brunauer-Emmett-Teller(BET) surface area, pore volume and pore diameter of Row-Clay, Na-Clay and Al-Clay were determined. The surface ereas found were 57.50; 65.83 and 67.65 respectivily for Raw-Clay, Na-Clay and Al-Clay. Statistical errors analysis were used to show the best fitting isotherm or kinetic models of the adsorption data. The results revealed that, natural and modified clay materials are made up of various functional groups characteristics of the minerals present on the surface of clay as shown by FTIR, qnd XRD. The equilibrium kinetic was reached at contact time of 5 min, 15 min and 20 min at pH = 3. According to the error analysis, the best isotherms that fit adequately the adsorption data was Sips and Hills isotherms of three parameters, Langmuir and Freundlich two parameters. Therefore, it was concluded that the local clay material has a dye removal capacity and could be exploited by the local people in clothing and textile industry as dye removal agent.

The mass transfer and energy efficiency in the “batch” and “Circulating” gliding arc configuration reactors for the direct discharges and degradation of pollutants in the aqueous solution have been investigated. The mass transfer characterization and energy efficiency in this study showed that the “Batch” configuration would be more efficient than the “Circulating” reactor. The difference between these reactors is due to the plasma (gas)–solution (liquid) contact time, therefore the gas–liquid transfer phenomenon. The lowest value of pH (2.5) and high temperature obtained in the “Batch” reactor contributes to better nitrogen oxides (NOx) transfer and solubility consequently the high conversion of the phenol in this reactor configuration (100% after 10 min of treatment) relative to that obtained in the circulating reactor (≈ 50% after 30 min) with pH 4.7.

The present work dedicated to the removal of Cr(VI) ions in aqueous solution onto a synthetized TiO2-AC composite. Composite characterization was carried out by determining of the point of zero charge pHpzc, iodine number, methylene blue index and FT-IR spectra. Adsorption experiments were conducted in batch mode and the influences of composite quantity, contact time, Cr(VI) ions concentration, ionic strength, and pH were studied. The highest adsorption were obtained in acid medium, with lowest adsorbent quantity (0.01 g) and initial solution concentration of 10 ppm. The results of kinetic studies revealed that Cr(VI) adsorption process on TiO2-AC composite followed pseudo second-order kinetic model. Non-linear regression was applied to equilibrium data and Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models were used for evaluation of adsorption parameters. The best-fitting was estimated based on correlation coefficient R2 value and the calculation of error deviations between experimental and predicted equilibrium adsorption data, using non-linear analysis. The results showed that Freundlich model describing adsorption process the best. The isotherm parameters from Langmuir and Freundlich models revealed that Cr(VI) adsorption mechanism on the composite is linear, spontaneous, and endothermic follows chemisorption process.

In this study, corn cobs and corn roots, agricultural by-products and wastes, were used as precursors for preparation of powder activated carbons (PAC-CC and PAC-CR) by chemical activation with H 3 PO 4 . Functional groups on the surface of both adsorbents were determined by using ATR−FTIR spectroscopy, while their specific surfaces area were calculated using methylene blue adsorption method . Removal of Crystal Violet (CV) dye from aqueous medium onto both adsorbents was carried out at optimal pH of 10. The pseudo-first order and pseudo-second-order models were used to study adsorption kinetics. The Langmuir and Freundlich, isotherm models were employed to analyze the adsorption isotherm. CV dye molecules-activated carbon surface interaction revealed CV dye’s monolayer formation over activated carbon’s surface and the involvement of chemisorption, as verified by Langmuir isotherm model and pseudo-second order model, respectively. Langmuir maximum adsorption capacity of PAC-CC and PAC-CR for CV dye were 41.80 mg/g and 35.92 mg/g, respectively. From these results, it can be concluded that the activated carbon prepared from corn cobs or roots as precursor can be used as adsorbent for successful removal of dyes in an aqueous medium.

The present work report removal of acid red 14 (AR14) and basic violet 3 (BV3) as anionic and cationic dyes, respectively, by adsorption process in batch mode from aqueous solution onto natural and modified forms of a local Cameroonian clay. The efficiency of these adsorbents materials (purified natural clay, P−Clay, sodium−clay, Na−Clay, and aluminium−pillared, Al−PILC) to remove dyes from aqueous medium was examined at different initial concentrations, pH, and ionic strengths. At the optimal contact time of 20 minutes, the maximum adsorbed dye amount on various adsorbents was obtained at pH 9 and pH 3 for AR14 and BV3 dyes, respectively. Adsorption process of both dyes on purified or modified clay was pH depend and the dyes molecules sorption over the clay surface occurs by electrostatic interactions. Ionic strength influenced significantly AR14 and BV3 dyes adsorption. Homo-ionization and pillaring clay increased its adsorption capacity. Kinetic studies showed that adsorption follows a pseudo−second−order model, and rate constants were evaluated. Non-linear fit of adsorption isotherm, qe vs Ce, were S−class for adsorption of both dye onto AL−PILC, indicating the heterogeneity of the adsorbent surface which leaded to a multilayer adsorption with interactions between dye molecules. Langmuir and Freundlich models were the best fits to the experimental data with the maximum adsorption capacities of AL−PILC for AR14 and BV3 dyes of 1.4 mg g-1 and 3.0 mg g-1, respectively. Lower adsorption capacities calculated from Langmuir isotherm model than the experimental values indicated adsorption mechanism occurs by multilayer formation on the adsorbent surface.

The aim of this work was to prepare a composite material based on cocoa cortex and sodium alginate and test it to remove Cu(II) ions in aqueous solution in batch conditions. The composite was characterized using elemental analysis, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA/DTG), and point of zero charge. The highest amount of adsorbed Cu(II) for the composite was 19.54 mg/g, i.e., 95.32% of an initial concentration of 100 mg/L. Under the same conditions, the cocoa cortex untreated exhibited extremely low adsorption, while when it was treated with hot soda, it adsorbed 13.67 mg/g. Adsorption by the composite reached the equilibrium after 220 min. Kinetic data analysis suggested that the process was governed by adsorption (pseudo-second-order model) and diffusion through macropores and/or mesopores (intra-particle model). The adsorption isotherm that best described the system was Langmuir’s. The maximum adsorption capacity of Cu(II) was 76.92 mg/g. The values of the thermodynamic parameters indicated that the process was spontaneous, with ΔG° values between (− 7.886 and − 9.458 kJ/mol) and endothermic, with ΔH° = 7.728 kJ/mol.

The majority of the analyzed calculi from patients are composed of calcium oxalate (CaOx) monohydrate whewellite (Wh) and CaOx dihydrate wedellite (Wd). The urinary calculi were identified by chemical and morphological analysis based on106 urine samples from human voluntary. The Crystalluria made by an optical polarized light microscopy. The oxaluria and urinary calcium were determined by conventional volumetric assays. The aim of this paper was to develop a simple system to predict and classify the type of crystalluria using Artificial Neural Networks (ANNs) algorithm.

The present paper reports the preparation and characterization of tetra-n-butylammonium bromide modified local clay material (TBAB-Clay) and its application as potential adsorbent material for Crystal violet dye removal from aqueous solution. Major mineral phases, identified by X-ray powder diffraction (XRD), were illite and kaolinite, in addition to quartz and calcite as impurities. Characterization of the material was supplemented by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The kinetics of the adsorption process was studied using two models: pseudo-first-order and pseudo-second-order models. Experimental data were best fitted with pseudo-second-order model. Three isotherm models namely the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) models were used for describing the adsorption process. The inclusion of non-linear regression analysis suggested the Langmuir model best described the adsorption process. The Langmuir isotherm predicted the maximum monolayer adsorption capacity of 115.54 mg g(-1) while the D-R isotherm suggested a physisorption process with a free energy value of 0.708 kJ mol(-1). Based on all the data in this study, this modified clay material is considered to be promising adsorbent for the removal of Crystal Violet dye from aqueous solution.