Biosorbent Amount Research Articles

Effective Biosorption of Auramin O Dye with Sustainable Chickpea Pods Waste; Isotherms, Kinetics and Thermodynamic Analysis

This study investigated biosorbent properties in removing Auramin O (AO) dye from the aqueous solution of agricultural wastes released from chickpea (Cicer arietinum L.), which is widely produced in Turkey and the world. Biosorption studies were carried out using different values of parameters such as initial AO concentration, dye pH, contact time, temperature, and biosorbent amount. Characterization analyses of the biosorbent used before and after biosorption were carried out by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FTIR), and point of zero charge (PZC). Biosorption isotherms were evaluated using Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models. As a result of experimental data, it has been shown that the Langmuir isotherm model (R2 = 0.930) is the most compatible model for biosorption, while the biosorption kinetic mechanism proceeds through the pseudo-second-order (PSO) kinetic model (R2 = 0.965) and the intra-particle diffusion model. As a result of thermodynamic studies, it has been reported that biosorption is endothermic (ΔH0>0), spontaneous (ΔS0>0), and entropy-increasing (ΔG0 <0).

Chemical modification of Aspergillus flavus extracted chitosan for uranium remediation from aqueous solution

ABSTRACT Fungal chitosan derived from Aspergillus flavus AFC was employed in the synthesis of a cross-linked polystyrene biopolymer, P-AFC, which was investigated as a biosorbent material for the effective removal of uranium ions U(VI) from aqueous solutions. The characterisation of both fungal biopolymers was achieved using Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy. The efficacy of the P-AFC biosorbent in removing uranium from an aqueous solution reached equilibrium in 240 minutes at an initial uranium concentration of 50 ppm, a biosorbent amount of 0.4 g/L, and a pH of 4.0. The maximum biosorption capacity for U(VI) was determined to be 128.21 mg g−1 at room temperature, calculated using the Langmuir model. Furthermore, kinetic and thermodynamic analyses indicated that the biosorption process was characterised by chemisorption, was exothermic, and occurred spontaneously (ΔHo = –59.98 kJ mol−1 and ΔSo = –113.32 J K−1 mol−1). Recycling experiments demonstrated that the material could be reused up to five times without a noticeable decrease in removal efficiency.

Plackett-Burman and Box-Wilson designs for the removal of mercury (II) by cypress pines and leaves, optimizing the surrounding conditions

In this study, the removal of Hg (II) from cypress leaves and cypress pines was examined. Factors like time of contact (1–60 min), amount of biosorbent used (0.02–0.06 min), pH levels (1.2–6.52 min), initial metal concentration (100–250 ppm) temperature (20–40 min), strength of ions (0.5–1.5 M), and speed of stirring (0–250 min) were studied. Kinetic data were described using both pseudo-first-order and pseudo-second-order models. Equilibrium data were analyzed using Langmuir and Freundlich models, with the Langmuir model fitting the data best. The kinetic data were best described by the pseudo-second-order model. Thermodynamic studies showed that the removal of Hg(II) by cypress leaves was exothermic. The Plackett–Burman design (PBD) and Box–Wilson designs were used for optimization, recommending values of 250 mg/L, 5.98, 7.98 min, and 0.5 g for the variables Co (initial concentration of Hg(II) ions), pH (acidity level), contact time, and mass of KNO3 (potassium nitrate) for the removal of mercury (II) by cypress pines.

Evaluation of biosorbent properties of Teucrium polium seeds in Rhodamine B removal; isotherm, kinetic, thermodynamic studies

Water pollution is a major environmental concern worldwide, particularly due to industrial paint waste. Therefore, treating wastewater from various industrial sources is crucial to restoring environmental quality. In this study, a batch biosorption system was used to investigate the biosorption of Rhodamine B (RhB), a highly toxic dye, on Teucrium polium seeds (TPS). The study examined the effects of different parameters such as initial dye concentration, contact time, initial pH, temperature, and biosorbent amount on RhB removal. To determine the physicochemical properties of TPS, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), and zero charge point (PZC) characterization analyses were performed. The maximum biosorption capacity of TPS at pH = 5.5 and 25 °C was found to be 4.18 mg g−1. The study found that the removal rate of RhB was 93.3% at an initial RhB dye concentration of 200 mg L−1. The experimental data showed that the Langmuir isotherm model (R 2 = 0.940) was the most compatible model for biosorption, while the biosorption kinetic mechanism proceeded through the pseudo-second-order (PSO) kinetic model (R 2 = 0.925). Additionally, the study found that intraparticle diffusion, pore diffusion, and film diffusion were effective in the RhB biosorption rate mechanism. Thermodynamic studies revealed that the biosorption was endothermic (ΔH0>0), spontaneous (ΔS0>0), and entropy-increasing (ΔG0 <0). As a result, TPS, which has suitable adsorbent properties for RhB, can be recommended as a new, cost-effective, abundant potential biosorbent.

Saccharomyces pastorianus Residual Biomass Immobilized in a Polymer Matrix as a Biosorbent for Reactive Dye Removal: Investigations in a Dynamic System.

The use of residual microbial biomass from various industries in emerging pollutant removal strategies represents a new area of research in the field. In this case, we examined how to remove reactive dyes from an aqueous solution utilizing a biosorbent made of residual biomass from immobilized Saccharomyces pastorianus (S. pastorianus) in a polymer matrix using a dynamic system. Fluidized bed column biosorption investigations were carried out on a laboratory scale. Brilliant Red HE-3B was chosen as the target molecule. The main parameters considered for this purpose were the flow rate (4.0 mL/min; 6.1 mL/min), initial pollutant concentration (51.2 mg/L; 77.84 mg/L), and biosorbent mass (16 g; 20 g). The experimental data of the fluidized bed study were evaluated by mathematical modeling. The Yoon-Nelson, Bohart-Adams, Clark, and Yan models were investigated for an appropriate correlation with the experimental data. An acceptable fit was obtained for a flow rate of 4 mL/min, an initial pollutant concentration of 51.2 mg/L, and a biosorbent amount of 20 g. The obtained results indicate that the biosorbent can be used efficiently in a dynamic system both for the removal of the studied dye and in extended operations with a continuous flow of wastewater. As a conclusion, the investigated biocomposite material can be considered a viable biosorbent for testing in the removal of reactive dyes from aqueous environments and creates the necessary conditions for the extension of studies toward the application of these types of biosorbents in the treatment of industrial effluents loaded with organic dyes.

Surfactant modified coconut husk fiber as a green alternative sorbent for micro-solid phase extraction of triazole fungicides at trace level in environmental water, soybean milk, fruit juice and alcoholic beverage samples.

In this work, micro-solid phase extraction using surfactant modified biosorbent was investigated for trace level determination of triazole fungicides prior to their analysis by high performance liquid chromatography. Coconut husk fiber (CHF) was selected as an effective biosorbent in the extraction process. Fourier transform infrared spectrometry, scanning electron microscopy and transmission electron microscopy methods were used to characterize the modified biosorbent. Various factors affecting the extraction efficiency of the proposed method were studied including the amount of coconut husk fiber biosorbent (0.1 g), kind and concentration of surfactant as a modifier (sodium dodecyl sulfate, 10 mmol L-1), kind and volume of desorption solvent (methanol, 150 μL), and extraction period (including vortex adsorption time, centrifugation adsorption time, vortex desorption time and centrifugation adsorption time approximately 10 min). Under the selected conditions, the calibration plot was found to be linear in the range of 9-300 μg L-1 with a coefficient for determination of greater than 0.99. The limits of detection and limits of quantification for the studied triazole fungicides were 3.00 and 9.00 μg L-1, respectively. Finally, the proposed method was successfully applied to determine triazole fungicides in environmental water, soybean milk, fruit juice and alcoholic beverage samples with acceptable recoveries obtained in the range of 67.0% to 105.0%.

Biosorption of tetracycline antibiotics by Lactarius deliciosus biomass

ABSTARCT In this study, Lactarius deliciosus biomass was used as a biosorbent for the biosorption of three tetracycline antibiotics, chlortetracycline (CTC), doxycycline (DC), and tetracycline (TC), from aqueous solution. The biomass was characterized by Fourier Transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The effect of biosorbent amount (0.01–0.1g), pH (3.0–8.0), initial antibiotic concentration (30–300 mg/L for CTC and DC, and 5–50 mg/L for TC), contact time (2–120 min), and temperature (7 °C, 16 °C, 25 °C) were investigated. The maximum biosorption amount of CTC, DC, and TC was 216.4 ± 4.2 mg/g (pH 4.0), 121.2 ± 6.2 mg/g (pH 3.0), and 23.2 ± 2.1 mg/g (pH 7.0) at 25 °C, respectively. The biosorption amount of tetracyclines decreased with increasing temperature demonstrating that the biosorption processes were exothermic. The biosorptions of tetracyclines were favorable with negative ΔG° values for all temperatures. CTC and DC biosorption processes were well fitted to the pseudo-second-order kinetic and Freundlich isotherm models. TC biosorption data obeyed the pseudo-first-order kinetic model. Tap and drinking water samples spiked with tetracyclines were used as real samples for biosorption. The results showed that L. deliciosus biomass could be effectively used as a biosorbent for tetracycline antibiotics with high adsorption capacities.

Bacteria immobilized onto carbon nanofiber as a composite for effective removal of arsenic from wastewater

Drinking arsenic-contaminated water is one of the major fears for the health of mankind due to its being of highly toxic and carcinogenic substance. In this perspective, the present work is aimed to prepare Enterococcus faecalis (E. faecalis) immobilized onto carbon nanofiber (CNF) as novel composite sorbent and evaluate it adsorption ability for removal of arsenic ions As(III) from aquatic medium. The Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM)/Energy Dispersive X-Ray (EDX) analysis results displayed that the modification of CNF particles with E. faecalis makes more sorptive sites and the surface functional groups for binding arsenic ions. The designing of the experiment (DOE) methodology was applied to assess the effects of experimental factors on the sorption yield and their significance levels. The designing of factorials was utilized to estimate responses and statistical correlation among experimental parameters. The response surface plots exhibited that the response was higher at an optimum level of variables used in the extraction of arsenic. The equilibrium data under optimized sorption conditions (temperature 24 °C, contact time 30 min, biosorbent amount 500 mg/L and pH 5) were studied for Langmuir and Freundlich isotherms and the data were well fitted to the Langmuir isotherm with obtained maximum removal capacity of 255.2 mg g−1 for monolayer As(III) sorption onto E. faecalis/CNF composite. The sorption mechanism for kinetic studies followed the pseudo-second order model with obtained correlation coefficient (R2 = 0.998). Based on characterization and surface functionalities the proposed adsorption mechanism, the hydrogen bonding, π–π and electrostatic attractions were efficient for bisorption of As(III) onto E. faecalis /CNF composite.

Lychaete pellucida as a novel biosorbent for the biodegradation of hazardous azo dyes

The majority of textile wastes are made up of toxic dyes. Additionally, because these compounds are soluble, wastewater may include significant concentrations. In this work, the green alga Lychaete pellucida is used for the bioremoval of four common azo dyes, Reactive Blue 4 (RB4), Reactive Red 120 (RR120), Reactive Brilliant Yellow 3G (RBY3G), and Reactive Green12 (RG12), with the application of two models of sorption isotherms, Langmuir and Freundlich. The spectrophotometer method was used to identify optimum conditions (temperature, pH, dye concentrations, algal biomass, and contact time) to remove these dyes onto dry freshwater macroalgae. The optimum pH for L. pellucida was 8. The optimum biosorbent amount is 2 g/L. Then, the best-removed dye concentration was 5 mg/L, the optimum contact duration was 120 min, and the optimum temperature was 25 °C. Under optimum conditions, the percent of dye removal was about 95% for all used azo dyes. This is the first report on the use of Lychaete pellucida for the efficient biodegradation of hazardous azo dyes.

Investigation of Effective Removal of Auramine O Dye by Pyracantha Coccinea Biosorbent: Isotherm and Kinetics

In this study, the effect of biosorbent dosage (0.1-0.4 g/L), dye pH (3.0-9.0) and initial dye concentration (50-500 mg/L) on synthetic Auramine O (AU-O) dye removal of biosorbent produced from Pyracantha coccinea (PC) plant by physical modification was investigated and the dye removal behavior of the biosorbent was investigated by kinetic and isotherm experiments. In the batch experiments, it was observed that as the adsorbent quantity was raised from 1 g/L to 4 g/L at a consistent dye concentration, the adsorption capacity declined from 69.25 mg/g to 22.73 mg/g. The adsorption capacities of AU-O dye at concentrations of 50 mg/L and 100 mg/L were determined to be 22.350 mg/g and 72.35 mg/g at 200 mg/L, respectively. The reason why there was no significant increase in adsorption capacity at higher dye concentrations (250-500 mg/L) was that at constant amount of biosorbent, the change in adsorption capacity was minimal since the active sites of the biosorbent reached saturation. The adsorption capacity was determined to be 26.512 mg/g, 38.74 mg/g, and 44.07 mg/g at pH:3.0, pH:4.88, and pH:7.0, respectively. It has been determined that the adsorption capacity achieved at pH 9.0 (44.21 mg/g) was nearly equivalent to the adsorption capacity observed under neutral pH conditions. The adsorption mechanism is best explained by the Langmuir isotherm (qm:123.10 mg/g and R2:0.990) and the pseudo-second-order kinetic models (R2: 0.985) in the adsorption isotherm and kinetic research.

Comparison of biosorption efficiency for hexavalent chromium remediation in synthetic wastewater using unmodified and chemically modified chicken feathers

The aim of the present study was to compare the effectiveness of raw chicken feathers (RCFs), NaOH and ethylenediamine-modified chicken feathers (MCFs), and xanthate-modified chicken feathers (XMCFs), treated with both NaOH, ethylenediamine, and carbon disulfide. The physicochemical characteristics of the biosorbents were analyzed using attenuated total reflection Fourier transform infrared spectrophotometry (ATR-FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), adsorption of N2 at −196°C and point of zero charge determination (pHpzc). The biosorption of Cr(VI) using MCFs and XMCFs was evaluated through various parameters, namely, pH, biosorbent amount, and contact time in batch experiments. The results showed a significant increase in the biosorption capacities of MCFs (90.90 mg/g) and XMCFs (100 mg/g) compared to RCFs (52.63 mg/g). The batch adsorption experiments indicated that the optimal conditions for biosorption were pH 2.0, with an equilibrium contact time of 90 min for RCFs, and 60 min for both MCFs and XMCFs. The optimal biosorbent concentrations were 16 g L−1 for RCFs and 12 g L−1 for both MCFs and XMCFs. The biosorption behavior was well described by the Langmuir isotherm and pseudo-second-order kinetic models. The thermodynamic parameters indicated that the biosorption of Cr(VI) onto the biosorbents was a spontaneous and endothermic process. Desorption analysis was carried out using a 0.1 M NaOH solution.

Dynamic removal of Pb(II) by live Dunaliella salina: a competitive uptake and isotherm model study.

The main aim of this study is modeling of a continuous biosorption system for the removal of Pb(II) ions in the aqueous conditions using live Dunaliella salina microalgae. The live microalgae can grow in saline water and opens new opportunities in varying the amount and properties of biosorbent. The effects of five parameters, including pH, optical density of algae as a factor indicating the adsorbent dosage, injection time, contact time, and initial concentration of Pb(II), were optimized by means of response surface methodology (RSM) based on the central composite design (CCD). Dunaliella salina algae showed maximum Pb(II) biosorption with 96% efficiency. For the selective Pb(II) uptake in the presence of Cd(II) and Ni(II), binary and ternary systems of ions were chosen. The mutual effect of each heavy metal ion in all systems on the total uptake percentage was also examined. The ion selectivity was investigated in the presence of diverse heavy metal ions, and the Pb(II) uptake percentage was determined to be 80%. Both Langmuir and Freundlich isotherm models were suitable for describing multicomponent binary and ternary systems depending on the presence of competitive ions in the mixture. Main functional groups and surface properties of the Dunaliella salina were identified by Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive spectrometry. Hence, effective heavy metal ion uptake, simple design, and cost-effective cultivation confirmed live Dunaliella salina as suitable microalgae for purifying contaminated water in an economic and safe manner.

Evaluation of Residual Yeast from Brewery Industry for Inactive Biosorption of Selenium from Industrial Wastewater: a Case Study.

In this study, the second-life application of Saccharomyces cerevisiae obtained from brewery wastewater was evaluated in the biosorption of Se(IV) (Na2SeO3) sorbate in residue generated from a fine chemical industry. Biosorption experiments were carried out with different Se(IV) concentrations (A = 7.5 to 30.0 mg L-1 dissolved in deionized water or industrial effluent) and different biosorbent concentrations (B = 2.0 to 52.5 g L-1, dry mass). Inactive microbial biomass was evaluated in a wet and dehydrated state. The highest selenium removal efficiency (biosorption efficiency-R = 97.5%) was achieved with the same concentrations of sorbate in deionized water, using 24.0 g L-1 of wet cells. In contrast, the industrial effluent treatment showed lower biosorption efficiency (R = 83.3%) due to a large amount of other salts in the medium, mainly sulphur. Overall, the use of smaller amounts of biosorbent had a biosorption capacity of approximately five times greater than when 24.0 g L-1 in industrial effluent treatment was used. However, as reducing the concentration of the contaminant contained in the wastewater is the primary goal of this study, a more significant amount of biosorbent is recommended.

Congo Red Biosorption with Dried Mint Leaves; Isotherm and Kinetic Studies

The development of the industry has resulted in a proportional increase in waste materials. Waste industrial products play a major role in the pollution of nature along with seas, lakes, and various water resources around the world. Organic dyes, which do not degrade in nature and have carcinogenic effects, are important industrial wastes. The improvement of wastewater is a research topic that has gained importance in recent years. In this study, the biosorption of Congo red dye from aqueous solution with dried mint leaves was investigated. The experiments were carried out at 20 °C and the natural pH of the dye. The process was optimized by examining the parameters of initial dye concentration, amount of biosorbent and contact time. It was determined that the biosorption equilibrium conformed to the Langmuir isotherm (R2=0.9815) and the maximum biosorption capacity (qmax) was 60.24 mg/g. In addition, the process conforms to the pseudo-second-order (R2=0.9946) kinetic model. As a result of the process, the removal of the Congo red dye from the dried mint leaves from the aqueous solution was achieved at a level of approximately 70%.

High accuracy prediction of Cu(II) cations removal from synthetic aqueous solutions with ANNs using normal and modified biosorbent

ABSTRACT This study aims to accurately predict Cu(II) removal efficiencies from synthetic aqueous solutions with Artificial Neural Networks (ANNs) using normal and modified Abies bornmulleriana cone. The predicted values of Cu(II) removal efficiencies for normal and modified Abies bornmulleriana cone were determined using a single ANNs model structure. In the present investigation, the neural network’s input parameters are biosorption time, biosorbate concentration, biosorbent amount, pH, particle size, agitation rate, and temperature. The removal efficiencies of the Cu (II) ions were selected as the experimental responses. The optimal network design is (7:7-9-2:2). Sensitivity analysis was employed to estimate the relative contribution of the input parameters to the ANN’s performance. The most critical parameter affecting the removal efficiencies of the Cu(II) was defined as biosorption time. The ANNs model for the normal and the modified Abies bornmulleriana cone had determination coefficients of (0.95, 0.98), standard deviation ratios of (0.22, 0.14), root mean square errors of (27.89, 26.02), and mean absolute errors of (2.21, 2.06), respectively. The outcomes from the network signify that the ANNs model could predict high accuracy Cu (II) removal efficiencies for both biosorbents.

Attenuation of nitrate from aqueous solution using raw and surface modified biosorbents from Adansonia digitata fruit pericarp

The prevalence of nitrate in potable water is a serious environmental concern. Several methods for eliminating nitrate from water have been made and implemented. During the course of this research, raw (RADFP) and surface-modified fruit pericarp (SMADFP) biosorbents derived from the Adansonia digitata plant were applied in order to remove nitrate from an aqueous solution. The external features of the biosorbents were studied with the aids of SEM and BET. The FT-IR spectrometer was utilized for identification of the functional groups of the adsorbents. A UV-Vis device was used to quantify the nitrate concentration. The adsorbents under investigation exhibit a heterogeneous pore structure with a considerable number of mesopores, with surface areas of 361.527 and 379.877 m2 per gram for RADFP and SMADFP, respectively. FT-IR spectra revealed the presence of carboxyl, hydroxyl, carbonyl, and halogen groups on the adsorbent. The maximum nitrate removal efficiencies of RADFP and SMADFP were 64.55 and 88.95%, respectively. The maximum adsorption efficiencies are achieved when the pH is 2, the starting concentration is 27.50 mg/L, the contact period is 75.00 min, and the amount of biosorbent is 5.50 g. RADFP and SMADFP have a removal capacity of 12.45 as well as 25.18 mg per gram and adsorption intensity of 3.2300 and 5.4500, respectively. The investigational values for the elimination of nitrate ions concurred well to both Freundlich and Langmuir models with R2 values of 0.99917 and 0.99763 for RADFP and SMADFP, respectively, and pseudo-second-order kinetic model with R2 values of 0.99817 and 0.99947, respectively for RADFP and SMADFP. It can be concluded that SMADFP is a relatively better biosorbent than RADFP, which will be utilizable for the remediation of nitrate from an aqueous solution.

Biosorbents Based on Biopolymers from Natural Sources and Food Waste to Retain the Methylene Blue Dye from the Aqueous Medium.

The use of a biosorbent based on residual biomass from brewing industry (Saccharomyces pastorianus) immobilized in a natural biopolymer (sodium alginate) was investigated for Methylene Blue removal from aqueous medium. Saccharomyces pastorianus, immobilized by a simple entrapment technique and by microencapsulation in alginate was characterized using SEM, EDAX, pHPZC and the biosorption behavior toward organic pollutant, such as cationic dye. The biosorption experiments were studied by assessing, in a first stage, the influence of the most important operational physical parameters on the efficiency of the biosorbent: the initial concentration of the dye, the contact time between phases, the temperature, the dye solution pH, the biosorbent granule size, and the amount of biosorbent. The highest sorption capacity was obtained for the biosorbent obtained by microencapsulation, at pH 9, at biosorbent dose of 5.28 g/L and a contact time of about 100 min. The biosorption equilibrium was then studied by modeling the data on the Langmuir, Freundlich and Dubinin- Radushkevich isotherms. The Langmuir model is best suited for experimental data on both particle sizes leading to a maximum biosorption capacity of 188.679 mg/g at room temperature. The values of the adsorption energy, E, obtained with the help of the Dubinin-Radushkevich model-suggest that the type of mechanism (physical or chemical) involved in the biosorption process depends on the particle size of the biosorbent. The results confirm that the residual microbial biomass of Saccharomyces pastorianus immobilized in a polymeric matrix such as sodium alginate, can be considered an efficient biosorbent in retaining cationic organic dyes present in aqueous solutions in moderate concentrations.

Biosorption of copper (II) from aqueous solutions by raw and chemically modified Thymus pannonicus in batch and fixed-bed systems

ABSTRACT In this study, the Cu(II) biosorption potential of the raw (RTP) and modified Thymus pannonicus (MTP) leaves was investigated in batch and continuous systems. FTIR, SEM, SEM-EDX and Zeta potential analyses were used for the characterisation of biomass. In the batch system, pH, amount of biosorbent, initial heavy metal concentration, contact time and temperature parameters were studied. According to the optimum pH and biosorbent amount determined in the batch system, the effect of the flow rate and column bed height on the biosorption was investigated by MTP in the continuous mode. Langmuir and Freundlich isotherm models were used to explain the biosorption mechanism, and it was seen that both biomasses conformed to the Langmuir isotherm. Pseudo-first-order and pseudo-second-order kinetic models were used in kinetic studies, and both RTP and MTP followed the pseudo-second-order kinetic model. While the equilibrium was established in 20 min in the removal of Cu(II) with RTP, this value increased to 30 min with MTP. The maximum monolayer biosorption capacity was determined as 46.21 mg/g for RTP and 82.70 mg/g for MTP. Column studies showed that the MTP was successful in removing Cu(II) from the solution in the continuous system.

Application of biorefinery by-product of Nigella sativa L. herb for green treatment of synthetic dye impurity in aquatic environment: a circular economy based approach to water purification

In this work, the performance of residual biomass of Nigella sativa L. plant from the process of bio-oil production toward the green removal of synthetic dye pollution from aquatic medium was systematically studied for the first time based on the circular economy strategy. The characterization of material was performed using Electron Microscope of Scanning and Infrared Spectrometer of Fourier Transform. The main process variables like pH, biosorbent amount, synthetic dye loading, and contact duration were optimized by the batch biosorption experiments to achieve the maximum remediation yield. The analyses of kinetics, equilibrium, and thermodynamics were conducted to understand the possible mechanism of purification. The experimental dynamics and equilibrium data were in better agreement with the pseudo-second-order and Langmuir models. For the targeted model synthetic dye compound (C. I. Basic Red 46), the biosorption capacity was obtained as 136.2 mg g−1 at the optimized conditions of pH of 8, biosorbent amount of 10 mg (100 mg L−1), synthetic dye loading of 30 mg L−1, and duration of 360 min. The treatment process was favorable, spontaneous, and physical. The characterization operation showed that the dye molecules were restrained on the rough surface of biosorbent. This study reveals that the reuse of herbal oil refinery residue as a biosorbent can present an economic, efficient, and eco-friendly option for the remediation of synthetic dye pollution in aqueous medium.

Rapid elimination of copper (II), nickel (II) and chromium (VI) ions from aqueous solutions by charcoal modified with phosphoric acid used as a green biosorbent

AbstractActivated carbon modified by phosphoric acid noted CAa was successfully used as a new low‐cost adsorbent for removing Cu2+, Ni2+ and Cr6+ metal ions from artificially contaminated aqueous solutions. Experiments were performed in batches for adsorption kinetics and isotherms. Scanning electron microscope (SEM) observations as well as a nitrogen adsorption–desorption BET surface area measurement showed the formation of mesoporous CAa with an average pore size of 3.1 nm and a surface area of ABET = 678.74 m2 g−1. The adsorption data for Cu2+, Ni2+ and Cr6+ fitted well with Langmuir adsorption model with maximum adsorbed amount of 238.10 mg g−1 for Cu(II), 80.64 mg g−1 for Ni(II) and 125 mg g−1 of Cr(VI) with the maximal amount measured by N2 adsorption of 231.5337 cm3 g−1 STP. The experimental variables studied were pH, temperature, amount of biomass and initial ion concentration. Maximum biosorption was observed for pH = 2. The adsorption capacity seems to be optimized by increasing the temperature, the amount of biosorbent and the initial concentration. Isotherm adsorptions are in agreement with Langmuir models. The calculated changes in adsorption free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) confirm that the present adsorption process is a favorable, endothermic and spontaneous phenomenon.