Biosorbent Dosage Research Articles

Ability of Moringa Ore (Moringa Oleifera) As Biosorbent in Used Cooking Oil Processing

The results of this study stated that the use of activated moringa ore biosorbents had a great influence on the quality of cooking oil both physically and chemically. The results of data analysis based on variations in contact time and dose variations can show that free fatty acid levels have decreased but are not in accordance with the stipulated SNI, namely 0.17%. Activation of Moringa ore using Sodium Hydroxide (NaOH) can reduce the levels of free fatty acids in used cooking oil. Variation of biosorbent contact time can affect the decrease in fatty acid levels, which occurs at the optimum contact time of 90 minutes, the free fatty acid percentage of 0.17% is not in accordance with SNI. Variations in biosorbent doses can also affect the increase in free fatty acid levels, namely the optimum dose of 1.00-gram percentage of free fatty acids decreased by 0.17% not according to SNI. Variations in contact time and variations in optimum doses of biosorbents can also affect color organoleptic tests and the smell of used cooking oil. Where the results of each respondent's statement that 95% of the refined oil using Moringa ore biosorbent are similar to new cooking oil, namely with a bright yellow color. The method used in this study is a quantitative method by conducting experiments on the subjects to be studied and used as a reference for finding and obtaining data directly through observation or experimentation

Investigation of kinetic, isotherm and adsorption efficacy of thorium by orange peel immobilized on calcium alginate

In this research work the thorium uptake on immobilized protonated orange peel was studied in a batch system. The effects of effective parameters such as biosorbent dosage, initial metal ion concentration, and contact time on the biosorption of thorium were analyzed. The biosorption capacity of the immobilized orange peel for thorium at optimal conditions of initial pH 3.8, biosorbent dosage 8 g/L, and initial thorium concentration 170 mg/L was found to be 18.65 mg/g. According to the results of contact time, the biosorption process reached equilibrium after around 10 h of contact. Investigation of the kinetics showed that the biosorption of thorium onto immobilized orange peel follows the pseudo-second-order model. The Langmuir and Freundlich isotherms were used to model the experimental equilibrium data. The results showed better agreement by the Langmuir isotherm. The maximum absorption capacity of immobilized protonated orange peel for thorium adsorption was predicted by the Langmuir isotherm at 29.58 mg/g.

Potential use of extracellular polymeric substances (EPS) of Bacillus subtilis for biosorption of mercury produced from soil-washing effluent

Extracellular polymeric substances (EPS) can be used as an effective biosorbent for removing heavy metals from soil washing effluent. In this research, Bacillus subtilis was used as an EPS-producing bacteria with a yield of bound EPS of 0.6 mg/g biomass with protein and polysaccharide content of 199 mg/g EPS and 8.8 mg/g EPS, respectively. The maximum biosorption capacities for mercury in artificial wastewater using bound EPS and dead biomass of Bacillus subtilis as biosorbents were 9.32 mg/g and 6.04 mg/g, respectively, at a biosorbent dose of 0.1 g/100 mL. Biosorption using Bacillus subtilis fitted the Langmuir isotherm, while biosorption using bound EPS fitted the Freundlich isotherm. The biosorption process followed a pseudo-second-order kinetic model for both biosorbents. Bound EPS was also feasible to treat soil washing effluent with a biosorption capacity of 2.21 mg/g of mercury. The use of bound EPS could effectively remove mercury from wastewater.

Development and Characterization of Biosorbent Film from Eggshell/Orange Waste Enriched with Banana Starch.

The conversion of waste into a valuable product is regarded as a promising alternative to relieving the burden of solid waste management and could be beneficial to the environment and humans. This study is focused on utilizing eggshell and orange peel enriched with banana starch to fabricate biofilm via the casting technique. The developed film is further characterized by field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The physical properties of films, including thickness, density, color, porosity, moisture content, water solubility, water absorption, and water vapor permeability, were also characterized. The removal efficiency of the metal ions onto film at different contact times, pH, biosorbent dosages, and initial concentration of Cd(II) were analyzed using atomic absorption spectroscopy (AAS). The film's surface was found to have a porous and rough structure with no cracks, which can enhance the target analytes interactions. EDX and XRD analyses confirmed that eggshell particles were made of calcium carbonate (CaCO3), and the appearance of the main peak at 2θ = 29.65° and 2θ = 29.49° proves the presence of calcite in eggshells. The FTIR indicated that the films contain various functional groups, such as alkane (C-H), hydroxyl (-OH), carbonyl (C=O), carbonate (CO32-), and carboxylic acid (-COOH) that can act as biosorption materials. According to the findings, the developed film exhibits a notable enhancement in its water barrier properties, thereby leading to improved adsorption capacity. The batch experiments showed that the film obtained the maximum removal percentage at pH = 8 and 6 g of biosorbent dose. Notably, the developed film could reach sorption equilibrium within 120 min at the initial concentration of 80 mg/L and remove 99.95% of Cd(II) in the aqueous solutions. This outcome presents potential opportunities for the application of these films in the food industry as both biosorbents and packaging materials. Such utilization can significantly enhance the overall quality of food products.

Optimized removal of cadmium, copper and lead from wastewater by biosorption using cabbage waste and Box-Behnken design (BBD)

In this study a Box-Behnken (BBD) design was applied to optimize biosorption of copper, cadmium, and lead using cabbage waste. The effects of operating parameters including initial pH, biosorbent dosage, contact time, and heavy metal concentration were determined by BBD. The maximum biosorption removal efficiency was achieved at pH 4, 300 min operation time, 1.5 g/250 mL biosorbent dosage, and an initial heavy metal concentration of 25 mg/L. The maximum removal efficiencies were 77.23% for Cu, 93.10% for Pb, and 67.19% for Cd at optimal conditions. The cabbage waste was found to be an effective, sustainable, locally available, and environmentally friendly biosorbent for removing heavy metals from aqueous solution.

Biosorption of Triphenyl Methane Dyes (Malachite Green and Crystal Violet) from Aqueous Media by Alfa (Stipa tenacissima L.) Leaf Powder.

This study includes the characterization and exploitation of an abundant agricultural waste in Algeria, Alfa (Stipa tenacissima L.) leaf powder (ALP) as a biosorbent for the removal of hazardous triphenylmethane dyes, malachite green (basic green 4) and crystal violet (basic violet 3), from aqueous media under various operating conditions in batch mode. The effect of experimental parameters such as initial dye concentration (10-40 mg/L), contact time (0-300 min), biosorbent dose (2.5-5.5 g/L), initial pH (2-8), temperature (298-328 K), and ionic strength on dye sorption was investigated. The results of both dyes show that the increase in initial concentration, contact time, temperature, and initial pH of solution leads to an increase in biosorbed quantity, unlike the effect of ionic strength. The biosorption kinetics for triphenylmethane dyes on ALP was analyzed by pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models proposed by the Weber-Morris equation. Equilibrium sorption data were analyzed by six isotherms, namely the Langmuir, Freundlich, Harkins-Jura, Flory-Huggins, Elovich, and Kiselev isotherms. The thermodynamic parameters were evaluated for both dyes. The thermodynamic results suggest that both dyes' biosorption is a typical physical process, spontaneous and endothermic in nature.

Intensification of strontium (II) ion biosorption on Sargassum sp via response surface methodology

A batch system was employed to investigate the biosorption of strontium (II) on Sargassum sp. The biosorption of strontium on Sargassum sp was studied with response surface methodology to determine the combined effect of temperature, initial metal ion concentration, biomass treatment, biosorbent dosage and pH. Under optimal conditions, the algae's biosorption capacity for strontium (initial pH 7.2, initial strontium concentration 300 mg/l for Mg-treated biomass and biosorbent dosage 0.1 g in 100 mL metal solution) was measured at 103.95 mg/g. In our analysis, equilibrium data were fitted to Langmuir and Freundlich isotherms. Results show that the best fit is provided by the Freundlich model. Biosorption dynamics analysis of the experimental data indicated that strontium (II) was absorbed into algal biomass in accordance with the pseudo-second-order kinetics model well.

Adsorption mechanism of nonsteroidal anti-inflammatories in wastewater using regenerable adsorbent (CCL): statistical modelling isotherm, kinetics and thermodynamic comparative studies

ABSTRACT The study was performed to investigate the biosorption mechanism of Diclofenac Sodium and Ketotifen Fumarate onto CCL biosorbent using isotherms models (Langmuir, Freundlich). Effects of parameters influencing the biosorption such as temperature, pH, biosorbent dose, contact time and biosorbate initial concentration were all investigated and optimised using a batch system. The comparison between various models indicates that the nonlinear form of Langmuir model was the best way to describe the equilibrium data that were approved using error functions: the coefficient of determination (R2), Average relative error (ARE), the sum of the squares of the errors (SSE), Marquardt’s percent standard deviation (MPSD), Hybrid fractional error function (HYBRID), Sum of the absolute errors (SAE) and ‘sum of the normalised errors (SNE)’ parameter. The kinetics experimental data was best predicted by the pseudo-second-order model. The adsorption mechanism identified external mass transfer as the principal measure of velocity control step. Thermodynamically, the process is spontaneous, exothermic and the adsorption was more favourable at lower temperatures. It was found that the regeneration is required as it changes the surface morphology of the biosorbent. Therefore, CCL biosorbent is considered as cost-effective and eco-efficient for removing Diclofenac and Ketotifen adsorbate from aqueous media by adsorption technique especially with its low cost preparation and regeneration.

Modeling and Optimization of Hexavalent Chromium Adsorption by Activated Eucalyptus Biochar Using Response Surface Methodology and Adaptive Neuro-Fuzzy Inference System

Due to its excellent textural features, non-toxicity, low cost and high uptake capacity, biochar has been synthesized from various biomasses and utilized as a biosorbent to remove hexavalent chromium (Cr6+) from contaminated water. Herein, activated eucalyptus biochar (AEB) was prepared via a pyrolysis-chemical activation process and then used as a less expensive biosorbent to adsorb Cr6+ ions from an aqueous solution. Proximate, ultimate, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) analyses were employed in appraising the biosorbent characteristics. Furthermore, response surface methodology (RSM) and adaptive neuro-fuzzy inference system (ANFIS) were applied to establish the best operating conditions. Based on the results obtained, there was little discrepancy between the observed data and the data predicted by RSM and ANFIS approaches. In terms of prediction accuracy, ANFIS (MAE = 2.512 and R2=0.9200) was superior to RSM (MAE = 2.512 and R2=0.9002). Under best-optimized conditions (initial Cr6+ concentration = 38.14 mg/L, biosorbent dosage = 1.33 g/L and pH = 4.35), which were offered by the ANFIS–ACO technique, the maximum percentage removal of 99.92 ± 0.18% was achieved. The AEB performed exceptionally well due to its better textural characteristics, well-developed porous framework, and dominance of active surface functional groups, which were confirmed by BET, SEM, and FTIR analyses. The comparison of RSM, ACO and GA for process parameter optimization has not been reported in the open literature for Cr6+ adsorption by AEB and hence has been shown in this study.

Chromochloris zofingiensis microalgae as a potential dye adsorbent: Adsorption thermo-kinetic, isothermal, and process optimization

In this study, the microalgae Chromochloris zofingiensis (ChZ) was harvested and used as a biosorbent for the removal of methylene blue (MB) as a model cationic dye from water. The ChZ was characterized via FTIR, FESEM-EDX, XRD and BET analyses. Response Surface Methodology, based on Central Composite Design was employed to optimize the batch adsorption process, including independent variables of biosorbent dosage, initial MB concentration and pH of the solution to maximize the MB removal percentage. The maximum removal of 97 % was obtained at the optimal conditions i.e., biosorbent dosage of 0.72 g/L, pH of 10 and initial MB concentration of 15.12 mg/L, with >97 % confidence limit. Pareto sensitivity analysis uncovered that the biosorbent dosage has the greatest impact (50 %) on MB removal. The adsorption kinetic was better described by the pseudo-second-order model among the different kinetic models applied i.e., pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich models. The adsorption equilibrium was also modeled using the Langmuir, Freundlich, Dubinin–Radushkevich and Temkin isotherms. The Langmuir model provided the best fit and the maximum sorption capacity of 135.42 mg/g was recorded. Principle thermodynamic criteria including ΔGo, ΔHo and ΔSo were computed for the biosorption. The results uncovered that the biosorption of MB using ChZ is spontaneous and exothermic. Generally, the results indicated that ChZ microalga can be considered an effective biosorbent for dye-contaminated water remediation.

Intensification of thorium biosorption onto protonated orange peel using the response surface methodology

Abstract In this research work, intensifying the possibility of protonated orange peel to uptake thorium (IV) ions from aqueous solutions in a batch system was investigated and optimized using the response surface methodology. The effect of three independent process variables including thorium initial concentration, pH, and biosorbent dosage was assessed based on the central composite design. The validity of the quadratic model was verified by the coefficient of determination. The optimization results showed that the rate of thorium (IV) uptake under optimal conditions is 183.95 mg/g. The modeling results showed that the experimental data of thorium biosorption kinetics are fitted well by the pseudo-second-order model. According to the results, the biosorption process reached equilibrium after around 4 h of contact. The Langmuir isotherm describes the experimental biosorption equilibrium data well. The maximum absorption capacity of protonated orange peel for thorium adsorption was estimated by the Langmuir isotherm at 236.97 mg/g. Thermodynamic studies show that thorium adsorption on protonated orange peel is thermodynamically feasible, spontaneous, and endothermic.

Valorization of Groundnut Shell Biomass for Biosorption of Hexavalent Chromium from Aqueous Solution

Biosorption is a cost-effective biotechnological innovation for the removal of heavy metals from aqueous solutions. There is widespread research into ways of utilizing agricultural residues to achieve zero waste. Groundnut shells are biodegradable waste available in large quantities. This study investigated the use of groundnut shells for the biosorption of chromium (VI) ions from an aqueous solution. Groundnut shells were cleaned and crushed to make fractions of particle size in the range of 90-1000 µm. The point of zero charge (pHPZC) and the distribution of oxygenated acidic and basic surface functional groups were determined. In batch experiments, the effect of acid pre-treatment, initial metal concentration, biosorbent particle size, biosorbent dosage, and contact time on biosorption was investigated. The biomass was found to have a pHPZC value of 6 and was dominated by acidic groups. The best biosorption activity was observed at 20 mg/L initial metal concentration and a biosorbent dosage of 10%. The effect of contact time was dependent on the initial chromium (VI) concentration. At 20 mg/L initial chromium (VI) concentration, the biosorption process reached equilibrium within 60 minutes whilst at high (>80 mg) chromium (VI) concentration equilibrium was not reached, even after 240 minutes. The best biosorption activity was observed with acid-treated biomass of particle size 300 µm. The adsorption fitted best with the Langmuir isotherm model and the pseudo-second-order kinetic model (R2 > 0.9982). Groundnut shell biomass has the potential for the removal of chromium (VI) ions from aqueous solutions and possibly from chromium-polluted effluents on an industrial scale.

Removal of chromium (VI) heavy metal ions through biosorption using betel seeds from aqueous solution

<p>The reduction of highly toxic Cr (VI) from industrial wastewater of low concentration by different low-cost ample sorbent materials was investigated. In order to remove Cr (VI) from aqueous solutions, the biosorption properties of natural waste (Betel Seeds) were investigated with varying several parameters like contact period, sorbent dose, sorbate sorption, and pH. The study's contact period, biosorbent dosage, sorbate concentration, and pH were all varied from 0 to 120 minutes, 12 g/l, 40 mg/l, and 2 to 7, respectively. According to the study, chromium sorption by betel seed powder reached equilibrium after 60 minutes, and a small change in chromium removal effectiveness was then noticed (Gode, et.al., 2003). At pH 3 and doses of 12 g/l and 30 mg/l of sorbent and sorbate, the maximum removal of chromium (99.2%) was achieved. The results revealed that chromium(VI) biosorption follows the Langmuir isotherm comparison with a correlation factor of 0.998. Additionally, the biosorption process's kinetics adheres to the pseudo-second-order kinetics model, with a rate constant of 0.721 min-1 and the rate constant was evaluated at 30°C. Hexavalent chromium in water was quantified using a UV-VIS spectrophotometer. A desorption examination was also carried out, and it is vital by 0.5H2SO4. Results indicate that the cheap, readily available, widely cultivated sorbent can be used to effectively remove chromium ions.</p>

Pressmud as Biosorbent for Reactive Dyes Removal from Wastewater

Abstract: Textile industry uses reactive dyes for dyeing. These textile effluents rigorously affect environment and living organisms. The study investigates use of “pressmud” a sugar industry waste, for preparation of biosorbent and its efficient use for removal of reactive dyes. In process, dried pressmud was pulverized and sieved (200-250 µm) followed by chemical activation by 5% HNO3 solution. Carbonization of pressmud was done at 400℃ for 3h. pressmud was characterized for XRD, FTIR. Factors affecting Biosorption process like pH, contact time, dye concentration, biosorbent dose were studied. Textile wastewater was analyzed before and after Biosorption for parameters like COD, BOD, TDS, turbidity etc. Adsorption isotherms like Langmuir and Freundlich isotherm were studied along with Temkin isotherm. The results showed removal of Orange dye followed Freundlich model (R2 =0.982) for Blue dye removal and treating textile wastewater, Langmuir model was best fitted (R2 =0.939, R2 =0.993). Maximum adsorption capacity of pressmud obtained was 151.51 mg / g. Reaction kinetics for Biosorption process was found to be Pseudo second order (R2 =0.984, 0.992, 0.999). The results indicated pressmud as promising material for preparation of low cost biosorbent and showed good dye removal efficiency.

Equilibrium, kinetics, and thermodynamics study on the biosorption of reactive levofloxacin antibiotic on Pithophora macroalgae in aqueous solution.

Since untreated wastewater from hospitals and residential areas is being discharged directly into surface waterways, pharmaceutical contaminants have been shown to be higher in many countries. Therefore, the development of novel and effective techniques to extract antibiotic substances from wastewater is of utmost importance. The present work aims at the use of green Pithophora macroalgae to remove levofloxacin antibiotic from an aqueous solution through biosorption. Biosorption is an economical and eco-friendly method for treating wastewater. The macroalgae were dried, grounded, and used as biosorbent to remove the levofloxacin (LVX) antibiotics from the aqueous solution. The influence of operating conditions such as initial antibiotic concentration, biosorbent dosage, agitation speed, pH, and temperature was studied. The biosorbent was characterized by FTIR, SEM, and point zero charge. The experimental data were evaluated using Langmuir and Freundlich isotherms. The experimental data best fit the Freundlich isotherm model (R2 = 0.969), while the kinetic model for the experiment follows the pseudo-second-order (R2 = 0.998) with a maximum biosorption capacity of 17.8mg/g. Maximized removal of LVX occurs at favorable conditions of 298K temperature, 150mg/L initial concentration of antibiotic, 0.5g sorbent dose, and 6.5 pH. The calculated thermodynamic parameters reveal that the biosorption of LVX antibiotics occurs by an endothermic process. This study deduces that Pithophora macroalgae biomass proved to be an effective biosorbent for biosorption of LVX antibiotics and may be a novel alternative method for antibiotics removal from aqueous solutions.

Alkaline Modification of Arabica-Coffee and Theobroma-Cocoa Agroindustrial Waste for Effective Removal of Pb(II) from Aqueous Solutions.

Arabica-coffee and Theobroma-cocoa agroindustrial wastes were treated with NaOH and characterized to efficiently remove Pb(II) from the aqueous media. The maximum Pb(II) adsorption capacities, qmax, of Arabica-coffee (WCAM) and Theobroma-cocoa (WCTM) biosorbents (qmax = 303.0 and 223.1 mg·g−1, respectively) were almost twice that of the corresponding untreated wastes and were higher than those of other similar agro-industrial biosorbents reported in the literature. Structural, chemical, and morphological characterization were performed by FT-IR, SEM/EDX, and point of zero charge (pHPZC) measurements. Both the WCAM and WCTM biosorbents showed typical uneven and rough cracked surfaces including the OH, C=O, COH, and C-O-C functional adsorbing groups. The optimal Pb(II) adsorption, reaching a high removal efficiency %R (>90%), occurred at a pH between 4 and 5 with a biosorbent dose of 2 g·L−1. The experimental data for Pb(II) adsorption on WACM and WCTM were well fitted with the Langmuir-isotherm and pseudo-second order kinetic models. These indicated that Pb(II) adsorption is a chemisorption process with the presence of a monolayer mechanism. In addition, the deduced thermodynamic parameters showed the endothermic (ΔH0 > 0), feasible, and spontaneous (ΔG0 < 0) nature of the adsorption processes studied.

Biosorption of Hexavalent Chromium by Bacillus megaterium and Rhodotorula sp. Inactivated Biomass

Due to the adverse effects of hexavalent chromium (Cr6+) on human health and the quality of the environment, the scientific community has invested a lot of effort to solve this pollution problem. Thus, implementing sustainable alternatives for Cr6+ elimination by exploiting the capacity of microbial biomass to retain heavy metals by biosorption is considered an economic and eco-friendly solution, compared to the conventional physico-chemical processes. However, the ability of microorganisms to remove Cr6+ from liquid effluents can strongly be affected by biotic and abiotic factors. With these issues in mind, the main purpose of this paper was to investigate Cr6+ biosorption on Bacillus megaterium and Rhodotorula sp. biomass inactivated by thermal treatments, exploring the effects of some factors such as: pH, biosorbent dose, initial concentration of the metal in solution, temperature and contact time between the biosorbent and the metal ions on process effectiveness. The results showed that Cr6+ removal by biosorption on the selected microorganisms was strongly influenced by the pH of the solution which contains chromium, the reduction being the principal mechanism involved in hexavalent chromium biosorption. Equilibrium and kinetic studies were also performed, together with SEM-EDX and FTIR spectra, to explain the mechanisms of the biosorption process on the selected biomasses. Maximum uptake capacities of 34.80 mg/g biosorbent and 47.70 mg/g biosorbent were achieved by Bacillus megaterium and Rhodotorula sp., respectively, at pH 1, biosorbent dosage of 8 g/L, 25 °C, after a contact time of 48 h and an initial Cr6+ concentration in solution of 402.52 mg/L. The experimental results showed that Cr6+ biosorption by selected microorganisms followed the Elovich model, the values of the correlation coefficients being 0.9868 and 0.9887, respectively. The Freundlich isotherm model best describes the Cr6+ biosorption by Bacillus megaterium and Rhodotorula sp., indicating that a multilayer biosorption mainly controls the process and is conducted on heterogeneous surfaces with uniformly distributed energy.

ANN modeling of lead adsorption from water using biowaste material as adsorbent

This research employed an Artificial Neural Network (ANN) approach to model the adsorption of lead from water using biowaste material as an adsorbent. To develop the ANN model, 39 experimental data point values for training and 15 experimental data point values for testing were used. The model involved the use of a tansigmoid transfer function for the input, purelin for the output, and a hidden layer consisting of 19 neurons to minimize the square error. The highest percentage of lead removal was achieved with optimal adsorption parameters (i.e., pH, concentration of lead, and biosorbent dosage). The experimental data closely matched the predicted values obtained from the ANN model with a R2 (regression coefficient) of 0.988. To determine the maximum percentage of lead removal and the optimal adsorption parameters, a pattern-search approach using a genetic algorithm was employed. In this study, adsorbent powder was prepared using biowaste materials, such as Borasus flabellifer coir.

Walnut shells as a potential biosorbent for Cu(II), Pb(II) and As(III)/(V) ions removal from river waters

In this study, the potential of the walnut shell as a biosorbent for biosorption of Cu(II), Pb(II), and As(III)/(V) ions from river water samples was investigated. The effects of various conditions of water samples such as the initial ion concentration, sample pH, and contact time at a constant temperature and biosorbent dosage, on biosorption of Cu(II), Pb(II), and As(III)/(V) were investigated. Walnut shells, as the material with a high potential for removal of investigated ions, have biosorption efficiency of up to 99.6%, under the applied experimental conditions. The best adsorption time was obtained at 4 h for Cu(II), Pb(II), and As(III)/(V) ions. The maximum removal of 97.6% (Cu(II)), 82.9% (Pb(II)), and 99.6% (As(III)/(V)) was obtained at pH=4.43, pH=8.55, and pH=7.84, respectively. Hence, the walnut shell shows potential of a cost-effective biosorbent that could be used for the treatment of contaminated rivers. However, further investigation is needed to fully explore this potential.

Biosorption of Congo Red Dye from Aqueous Solution Using Adsorbent Prepared from Vangueria infausta Fruit Pericarp

The adsorption efficiency of acid-treated Vangueria infausta fruit pericarp (VIFP) biosorbent to uptake Congo red (CR) dye was investigated through batch experiments. Optimum conditions for the adsorption process were determined by varying the solution pH, biosorbent dosage, contact time, initial concentration of CR dye, and temperature. Results revealed that the data fits well with the Langmuir isotherm model, demonstrating the monolayer coverage of the CR dye molecule on the surface of the VIFP biosorbent. The higher value of correlation coefficient, [Formula: see text] for pseudo-second-order (0.9997) compared to [Formula: see text] of pseudo-first-order (0.9605) suggests that the pseudo-second-order kinetic model is an ideal fit in describing the kinetics of CR dye adsorption by VIFP biosorbent. The positive value of [Formula: see text] (41.42 kJ/mol) and [Formula: see text] (158.32 J/mol.K) depicts the endothermic nature and spontaneity of the biosorption of CR dye by VIFP. The values of [Formula: see text] obtained were negative, showing that the adsorption is thermodynamically favourable. Therefore, the acid-treated adsorbent from Vangueria infausta can efficiently be used in the removal of CR dye from aqueous solution.