Green Adsorbent Research Articles

Magnetized cellulosic material from Cannabis biomass as a green adsorbent: Effective removal of paracetamol from wastewater

Magnetized cellulosic material from Cannabis biomass as a green adsorbent: Effective removal of paracetamol from wastewater

Biochar: a potential and green adsorbent for antibiotics removal from aqueous solution

Biochar: a potential and green adsorbent for antibiotics removal from aqueous solution

Synthesis and characterization of three-dimensional graphene oxide-chitosan/ glutaraldehyde nanocomposites: Towards adsorption of crocin from saffron

Despite the unique properties of graphene oxide (GO) as a green adsorbent, its low structural stability presents a drawback. This study aimed to modify the properties of GO through its functionalization with chitosan (CH), cross-linked with glutaraldehyde (GLU), and synthesized via the freeze-drying method (GO-CH/GLU). Microscopic analysis illustrated that covering the GO sheets with CH and nanoparticles (NPs) resulted in a 15.8 % increase in d-spacing and a 600 % increase in sheet thickness. The GO-CH/GLU composite was utilized for the separation/purification of crocin from saffron extract under varying pH (5–9), temperature (298–318 K), stirring rate (100–300 rpm), and crocin concentration (25–200 mg/mL). The Freundlich isotherm and pseudo-second-order kinetic models provided a good fit for crocin adsorption. Thermodynamic analysis revealed that the process was endothermic, spontaneous, and physical. Optimal adsorption conditions in batch mode were pH 7, a stirring rate of 300 rpm, a temperature of 318 K, and a crocin concentration of 100 mg/mL. These conditions were applied in a continuous system, resulting in a crocin separation efficiency of 94.17 % at 180 mL/h. Additionally, HPLC data indicated that the purity of separated crocin exceeded 90 %. So, the GO-CH/GLU composite is a promising and economical adsorbent for the food industry.

Simultaneous removal of Pb(II) and Cr(VI) from a steel company wastewater using various green adsorbents: Material characterization and numerical optimization

ABSTRACT This study focuses on the simultaneous uptake of Pb(II) and Cr(VI) from industrial wastewater by walnut shell (WS), almond shell (AS), peanut shell (PS), and coconut shell (CS) adsorbents. Among the used adsorbents, the CS adsorbent exhibited the greatest BET surface area of 18.97 m2/g and porosity of 63.17% and the WS adsorbent also had the highest pore volume of 0.3536 m3/g. Lead and chromium removal were optimized using response surface methodology via a central composite design (CCD) approach. The efficiency of lead and chromium uptake from the wastewater was enhanced by increasing the concentration of WS, AS, PS, and CS adsorbents (Cads.) and decreasing the flow rate (Q) of the wastewater. Under the optimal conditions (Cads. = 0.85 g/L and Q = 2.5 mL/min), the maximum lead and chromium uptake from steel company wastewater was achieved using CS (92%) and WS (97.2%) adsorbents, respectively. The actual lead and chromium removal values were well-fitted based on a high Rpred2, confirming the validity of the CCD model. The acceptable performance of these green adsorbents in the simultaneous removal of chromium and lead from the wastewater introduces the WS, AS, PS, and CS adsorbents as inexpensive and available candidates for industrial wastewater treatment containing heavy metals.

The adsorption and separation of tungsten and molybdenum by chitosan and chitosan-D301: Experiments and DFT theoretical calculation

The adsorption and separation of tungsten and molybdenum are important for efficient recycling of W-Mo resources, which requires green and efficient adsorbents. In this paper, Chitosan (CS)-D301 material was obtained by impregnation method and was applied to adsorb and separate W and Mo in solutions. The adsorption optimization results indicated that W was adsorbed by CS-D301, the separation factor of W/Mo increased to 26.45 compared with that of CS 21.34. The desorption efficiency was still above 94 % after five adsorption–desorption cycles. FT-IR, XPS and DFT theoretical calculations indicated that the surface group N+-R of CS-D301 showed more affinity for W, making it easier to selectively adsorb W over Mo than CS only. N was the surface-active adsorption site, and the adsorption process belonged to chemical adsorption with an adsorption energy of Eads = −957.64 kcal/mol. CS-D301 was expected to become green adsorbent for efficient separation of W and Mo to support resource recovery, protection and sustainable development.

Fe3O4/sugarcane bagasse magnetic composite: A low-cost and green adsorbent for enhanced adsorption of Rhodamine B from aqueous solutions

In this study, we have designed and synthesized an eco-friendly Fe3O4/sugarcane bagasse magnetic composite (Fe3O4/SCB). We investigated its application for efficiently removing Rhodamine B (RhB) from textile wastewater, a significant step towards addressing the environmental issue of textile dye pollution. The composite, made from sugarcane bagasse (SCB), a secondary product from the sugarcane industry, proved an effective adsorbent. The composite Fe3O4/SCB was characterized by PXRD, FT-IR, FE-SEM, VSM, BET N2 adsorption-desorption, and pHpzc. Results from batch adsorption studies show that the removal of RhB was 93.6 ± 1.16 % using a composite dose of 1 g/L, a RhB concentration of 10 mg/L, a contact period of 60 min, and a solution pH of 3 at 323 K of solution temperature. The kinetic studies indicate that the pseudo-second-order model most accurately describes the adsorption. Meanwhile, the equilibrium data is well-represented by the Freundlich isotherm. Further, the analysis of thermodynamic results, such as the changes in ∆Go, ∆So, and ΔHo, revealed that the adsorption was spontaneous, feasible, and endothermic. The adsorption mechanism involved chemisorption and physisorption, with significant roles played by electrostatic interactions and hydrogen bonding. Desorption studies identified 0.5 M NaOH as an effective desorbing agent, and the composite demonstrated excellent reusability over four adsorption-desorption cycles. Overall, the Fe3O4/SCB, with its easy preparation, abundance, cost-effectiveness, efficiency, and eco-friendly nature, presents a promising solution for effectively removing toxic RhB from aqueous solutions, inspiring further research and potential real-world applications.

Enhanced methyl green adsorption of ZIF-8 metal-organic framework: Insights from different solvents

Enhanced methyl green adsorption of ZIF-8 metal-organic framework: Insights from different solvents

An investigation into equilibrium, Kinetics, and thermodynamics of yellow bemacid dye removal from Aqueous Solutions using pomegranate skin (PG) and Date Pedicels (DPd) as Green Adsorbents

An investigation into equilibrium, Kinetics, and thermodynamics of yellow bemacid dye removal from Aqueous Solutions using pomegranate skin (PG) and Date Pedicels (DPd) as Green Adsorbents

Multifunctional electrospun membranes incorporated with metal oxide nanoparticles, cellulose acetate, and polyvinylpyrrolidone for wastewater treatment: Oil/water separation, dye adsorption, and dye degradation

Multifunctional membranes have gained considerable attention as useful materials for the treatment of complex wastewater that contains dye and oil substances. Electrospun nanofiber membranes (ENM) have substantial advantages and potential for complex wastewater remediation, owing to their unique properties. In this study, an environmentally compatible ENM is fabricated by incorporating photocatalytic metal oxide nanoparticles of zinc oxide (ZnO) or silver-zinc Oxide (Ag-ZnO) into cellulose acetate (CA)/polyvinylpyrrolidone (PVP) nanofibers using electrospinning. Composite membranes ZnO/CA/PVP, Ag-ZnO/CA/PVP, ZnO/DCA/PVP (DCA: deacetylated cellulose acetate), and Ag-ZnO/DCA/PVP (deacetylated) were employed for oil–water emulsion separation, owing to their superhydrophilic and underwater superoleophobic nature, photocatalytic dye degradation due to the presence of ZnO or Ag-ZnO, and dye adsorption resulting from their high surface area. The composite membranes showed more than 95% efficiency for oil/water separation, malachite green adsorption, and photocatalytic methylene blue degradation. These membranes displayed simultaneous oil–water and dye separation efficiency, as well as antibacterial properties. The membrane we present here provides a simple and effective platform for wastewater remediation with a low energy consumption.

Green synthesis of zero‐valent copper nanoparticles for removal of D‐yellow 119 textile dye from aqueous medium

AbstractZero‐valent copper nanoparticles (CuNPs) were beneficially green synthesized via Ficus Benjamina leaves. Applying scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT‐IR), Ficus Benjamina nano zero‐valent copper (FB‐nZVCu), an innovative adsorbent, was examined. The obtained zero‐valent CuNPs have a size range of 16–18 nm. The removal of D‐yellow 119 dye from textile wastewater was tested using this novel adsorbent. Many operating parameters were examined and tested to control the adsorbent's maximum removal efficiency. These variables included dye concentration, stirring rate, time, pH, and adsorbent dosage. Different adsorption mechanisms have been tested, and the Langmuir isotherm (qmax = 21.83 mg g−1) and (R2 = 0.9993) represent adequate for the adsorption process. The FB‐nZVCu green adsorbent is a promising material for eliminating D‐yellow 119 from simulated and real samples, according to the data obtained and the fruitful analysis. The impact of different operating factors was examined using IBM SPSS Statistics software. They were shown to be responsible for approximately 94% of the factors influencing the removal process.

A novel potato peels waste β-cyclodextrin biocomposite for the efficient uptake of diuron and glyphosate herbicides.

A novel biocomposite (FPPW-β-CD) was prepared by a simple and sustainable method involving fine potato peel waste, β-cyclodextrin (β-CD), and green citric acid through the crosslinking reaction. The polymer was characterized using SEM, FTIR, XRD, TGA, and DSC analyses. The adsorbent performance was evaluated about the glyphosate and diuron adsorption from the aqueous solution. Pesticide removal was investigated regarding the influence of solution pH, temperature, and initial concentration of contaminants. Also, it highlights the main interactions involved in the adsorption phenomenon based on the pH effect and characteristics of adsorbent and adsorbate molecules. The maximum adsorption capacity values according to the Sips model were higher than 2000µgg-1. The pseudo-second-order and general-order models described the kinetic data well. Thermodynamic parameters indicated that pesticide removal was spontaneous and favorable. The magnitude of enthalpy variation values (27.37kJmol-1 and - 100.79kJmol-1) revealed that the glyphosate and diuron adsorption occurred through the physisorption and chemisorption, respectively. The novel biocomposite is a promising green adsorbent for the uptake of micropollutant pesticides in aqueous solutions at concentrations of µg L-1.

Compost as Green Adsorbent for the Azo Dyes: Structural Characterization and Dye Removal Mechanism

The study aimed to determine the feasibility of using compost as a ‘green adsorbent’ for the removal of five anionic azo dyes belonging to the monoazo, disazo and trisazo classes: Direct Red 81 (DR-81), Direct Blue 74 (DB-74), Reactive Blue 81 (RB-81), Reactive Red 198 (RR-198) and Acid Black 194 (ABk-194) from aqueous solutions. The adsorption capacity of the compost was determined using a batch method with initial dye concentrations ranging from 1 to 1000 mg/L. The kinetics of dye removal followed a pseudo-second-order model, indicating chemisorption as the rate-limiting step. The monoazo dyes RB-81, RR-198 and ABk-194 with the smaller molecule size were adsorbed the fastest. The Langmuir and Sips models best fit the adsorption system with maximum adsorption capacities in the range of 12.64 mg/g (RR-198)—20.92 mg/g (ABk-194) and 12.57 mg/g (RR-198)—25.43 mg/g (ABk-194), respectively. The adsorption depended on the dye structure, especially on the ratio of the numbers of proton donors to proton acceptor locations in functional groups. The differences in the adsorption mechanism could be explained by thermodynamic properties such as dipole moments, HOMO–LUMO energy gap, polarizability, electron affinity, ionization potential, electronegativity and chemical hardness obtained by Density Functional Theory.Graphical

Citrus limon peel-based biosynthesis: Lead oxide, zinc oxide, cadmium oxide, and copper oxide nano quantum dots for subtraction of anionic Actas Pink dye (AAPD)

ABSTRACT Adsorption is a highly effective method for wastewater quality adjustment, offering advantages such as low cost and availability of adsorbents. This study investigates the efficient removal of Anionic Actas Pink dye (AAPD), a major contributor to environmental pollution. Green adsorbents including lead oxide (PbO), zinc oxide (ZnO), cadmium oxide (CdO), and copper oxide (CuO) were synthesized via eco-friendly routes for AAPD removal. Maximum adsorption capacities (qe) were observed at pH 7 (PbO, ZnO, CdO) and pH 2 (CuO and native) with values of 83.83 mg/g at 100 ppm, 75.65 mg/g at 100 ppm, 70.50 mg/g 75 ppm, 61.21 mg/g at 150 ppm, and 52.69 mg/g at 150 ppm, respectively, using an adsorbent dose of 0.05 g/50 mL at temperature of 37°C, and 90 min contact time. Adsorption followed Langmuir isotherm for all adsorbents except native, with PbO also fitting Freundlich and Dubinin–Radushkevich isotherms. Kinetics adsorption data supported pseudo-second-order, while thermodynamic analysis indicated spontaneous and exothermic nature. Effects of electrolytes, surfactants, and desorption were also evaluated. Characterization through FTIR, SEM, and XRD confirmed the morphology and functional groups of these nano-quantum dots. Citrus limon peel-based biosynthesis offers sustainable, eco-friendly, and cost-effective alternatives, highlighting their potential for dye adsorption.

Highly efficient malachite green adsorption by bacterial cellulose and bacterial cellulose/locust bean gum composite

In this study, bacterial cellulose (BC) and BC/locust bean gum (LBG) composite produced from banana hydrolysate were both used as the adsorbent for various organic dyes adsorption especially for malachite green (MG) adsorption for the first time. The BC/LBG(2%) composite exhibited significantly enhanced swelling rate and textural characteristics while maintained the basic structure of BC as depicted by XRD, FT-IR, and NMR, providing a foundation for its application as an excellent adsorbent. The composite exhibited a high adsorption rate and adsorption capacity for MG (exceeding 95 % and 2000 mg/g), and had a good selectivity for MG adsorption in the solution containing crystal violet (CV), rhodamine B (RB), and methyl orange (MO). The MG adsorption process conformed to multiple models including Langmuir and pseudo-first-order models. And the adsorption mechanism mainly comprised chemical adsorption (hydrogen bonding and electrostatic interactions) and physical adsorption. The reusability of BC/LBG(2%) composite was attractive for industrial application that the MG adsorption rate reduced merely a little (still higher than 88 %) after the 5th regeneration process. Overall, considering its adsorption capacity, selectivity, and reusability, BC/LBG(2%) composite prepared by in-situ fermentation with LBG addition was a competent adsorbent for MG adsorption and MG containing wastewater treatment.

An insight into the utilization of high-sulfur green Saudi Arabian petcoke as an ecofriendly sorbent for enhanced simultaneous sequestration of heavy metal ions from industrial wastewaters

Developing effective and green sorbents for the sequestration of water pollutants has increased attention to safe and sustainable water generation. This study aimed to discover a new utilization and the ability of green, high-sulfur Saudi Arabian petcoke (SA-PET) for heavy metal ion uptake. The organic sulfur content and aromatic properties of SA-PET allowed for rapid and improved performance against various metal ions via strong complex formation reactions and cation-π interactions. Also, the effects of different analytical factors were carefully studied and optimized. At pH 6–7, the maximum recovery values of PbII, CuII, CdII, ZnII, MnII, NiII and CoII metal ions were 21.09–95.76%. The experimental results demonstrate single-layer adsorption at the binding sites on the petcoke’s surface, and they are in good agreement with the Langmuir model in explaining the adsorption process, which is driven by electrostatic interactions between the petcoke surface and the studied metal ions. The pseudo-second-order kinetics model fits the adsorption data for all the target metal ions well. Furthermore, the outstanding SA-PET's stability allowed for efficient extractions over the course of 10 successive runs with negligible loss in the metal recovery percentage. With extraction recoveries up to 96.6% and a relative standard deviation less than 5%, SA-PET's efficiency in removing the target metal ions from different industrial wastewater samples gives it excellent promise as a novel green sorbent for detoxifying heavy metals from aquatic life. In conclusions, our findings, SA-PET emerged as a viable substitute for traditional synthetic adsorbents of heavy metals, in keeping with the growing trend toward green adsorbents for more sustainable development.

Green adsorbents for pharmaceutics removal from urine: Analysis of isotherms, kinetics, adsorption interactions, cost estimation, and environmental impact

Husks of rice (RH), coffee (CH), and cholupa (CLH) were used to produce natural adsorbents. The natural adsorbents were used to remove pharmaceuticals such as diclofenac, ciprofloxacin, and acetaminophen in a mixture of distilled water. However, CH stood out for its efficiency in removing ciprofloxacin (74%) due to the higher concentration of acidic groups, as indicated by the Boehm method. In addition, CH removed 86% of ciprofloxacin individually. Therefore, CH was selected and used to remove other fluoroquinolones, such as levofloxacin and Norfloxacin. Although electrostatic interactions favored removals, better removal was observed for ciprofloxacin due to its smaller molecular volume. Then, ciprofloxacin was selected, and the effect of pH, matrix, and adsorbent doses were evaluated. In this way, using a pH of 6.2 in urine with a dose of 1.5 g L−1, it is possible to adsorb CIP concentrations in the range (0.0050–0.42 mmol L−1). Subsequently, the high R2 values and low percentages of APE and Δq indicated better fits for pseudo-second-order kinetics, suggesting a two-stage adsorption. At the same time, the Langmuir isotherm recommends a monolayer adsorption with a Qm of 25.2 mg g−1. In addition, a cost of 0.373 USD/g CIP was estimated for the process, where the material can be reused up to 4 times with a CIP removal in the urine of 51%. Consequently, thermodynamics analysis showed an exothermic and spontaneous process with high disorder. Furthermore, changes in FTIR analysis after adsorption suggest that CH in removing CIP in urine involves electrostatic attractions, hydrogen bonds and π-π interactions. In addition, the life cycle analysis presents, for the 11 categories evaluated, a lower environmental impact of the CIP removal in urine with CH than for the preparation of adsorbent, confirming that the adsorption process is more environmentally friendly than materials synthesis or other alternatives of treatments. Furthermore, future directions of the study based on real applications were proposed.

Resourceful exploitation of sedimentary clay: Designing a dual-chambered borosilicate glass reactor system for the efficient treatment of malachite green and phenol through SCRT adsorption and 5%Fe@SRCT catalysis via CWPO, with evaluation of seed germination and fish survival.

This study presents an innovative double-walled borosilicate glass reactor system for the efficient treatment of liquid and gaseous wastewater. This reactor system allows precise temperature control, continuous pH monitoring, and controlled dosing of reagents to optimize reaction conditions. Detailed characterization was carried out by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), BET (specific surface area) analysis, point of zero charge (PZC), and scanning electron microscopy (SEM) for the SCR, SCRT, and 5%Fe@SCRT materials. For Malachite Green adsorption, SRCT demonstrated a maximum adsorption capacity of 39.78 ±0.5mg/g using the Langmuir isotherm model and followed pseudo-second-order kinetics. Optimum conditions for adsorption were found to be: an initial concentration of 50 ppm, an adsorbent dosage of 1g/l, a pH of 8.5, and a temperature of 50°C. For the catalytic oxidation of phenol, 5%Fe@SRCT achieved a remarkable removal rate of 99.9±0.1% under optimum conditions (50 ppm phenol, 1g/l catalyst dosage, pH3.5, H2O2 concentration 8.7mM, and temperature 70°C). Intermediates identified during the reaction included hydroquinone, benzoquinone, catechol, and resorcinol, with degradation occurring over a 60-minute reaction period. The 5%Fe@SCRT material showed excellent reusability in the removal of phenol by catalytic oxidation, with no significant loss of efficiency over three cycles, while the SRCT underwent three cycles of regeneration for the adsorption of Malachite Green. Scavenger tests confirmed the involvement of hydroxyl radicals in the catalytic oxidation process. In addition, fish survival tests after catalytic oxidation of phenol by 5%Fe@SRCT showed no impact on fish, underlining the environmental safety of this process. In addition, germination tests after decolorization of MG by SRCT demonstrated a good effect with no negative impact, reinforcing the ecological value of this innovative technology. These results highlight the innovative use of SCRT and 5%Fe@SCRT as versatile materials for environmental remediation, exploiting their effective adsorption capacities and efficient catalytic oxidation performance within the proposed double-walled borosilicate glass reactor system. PRACTITIONER POINTS: The study demonstrates the effectiveness of an innovative reactor system employing SRCT adsorbent and Fe@SRCT catalyst for efficient removal of malachite green and phenol from wastewater. Environmental impact assessment, including seed germination and fish survival evaluation, validates the method's eco-friendly potential. Implementation of this approach could significantly contribute to sustainable water treatment practices.

Potassium salts activated lignin-based biochar as an effective adsorbent for malachite green adsorption

Herein, a series of lignin-based porous carbons (LC) were prepared from sulfonated lignin through a simple and environmentally-friendly one-pot activated carbonization together with various potassium compounds as activators, and used for malachite green (MG) adsorption. The results showed that the prepared biochar, especially after K2CO3 activation, exhibited a honeycomb profile with large surface area (2107.6 m2/g) and high total pore volume (1.1591 cm3/g), having excellent efficiency for MG adsorption, and the biggest adsorption capacity was 2970.0 mg/g. The kinetic study together with thermodynamic analysis indicated that the adsorption of MG by LC-K2CO3 conformed to pseudo-second-order model and the adsorption process was spontaneous, feasible, and endothermic. Moreover, LC-K2CO3 also displayed good stability and selectivity, and can selective separate the cationic dye from binary-dye system. Furthermore, the adsorption mechanism proposed in this work manifested that the high-efficient MG adsorption by LC-K2CO3 was a result of multiple actions including hydrogen bonding, electrostatic attraction, π-π interaction and n-π interaction as well as physical absorption. The work not only provide a fundamental theory for dye removal from wastewater, but offered a new insight for lignin valorization.

Green adsorption of quinoline as basic N-compounds from liquid fuel using mesoporous and Fe-functionalized walnut shell-activated carbon

Removing nitrogenous compounds from liquid fuels is essential, and adsorption de-nitrogenation is a new process for this goal. This work has the purpose of investigating quinoline adsorption using Iron functionalized Activated carbon (IFAC) mesoporous nanocomposite. The mesoporous nanocomposite was synthesized in a one-step process by chemical activation of the walnut shell using Iron chloride as the activation and modification agent. The IFAC mesoporous nanocomposite was utilized to remove quinoline from isooctane as the liquid fuel via a discontinuous (batch) process by examining the effect of initial concentration, contact time, and temperature. The effect of contact time on the adsorption ability of IFAC for quinoline was well described by the pseudo-second-order model. The Langmuir model described the equilibrium manner of the process well, and the adsorbent could retain 344.82 mg/g of quinoline (37.37 mg N/g). The thermodynamic parameters show the endothermic (ΔH°= +30.070 kJ/mol) and spontaneity of the adsorption process. The regeneration experiments indicated that functionalized AC’s adsorption ability for quinoline adsorption decreased by 23% after five cycles. The obtained data indicate that the functionalization of activated carbon surface with iron particles leads to improving its adsorption ability toward N-containing compounds from liquid fuels.

Optimizing malachite green adsorption with Co-PTC metal organic framework: Insights into mechanisms and performance

The removal of organic pollutants from aqueous environments has garnered significant attention in environmental science and engineering. Metal-organic frameworks (MOFs) have emerged as promising materials for this purpose due to their intriguing structures, high surface area, and perpetual porosity. In this study, we investigate the adsorption performance of Co-based MOF for the removal of malachite green (MG), a common organic dye pollutant. The MOF, abbreviated as Co-PTC is synthesized via a one-pot green approach using perylene-3,4,9,10-tetracarboxylic dianhydride (PTC) as the ligand at room temperature. Basic to advanced characterization techniques are employed to elucidate the structure and interactions within the MOF. Through a comprehensive analysis, the underlying mechanisms governing the adsorption process are explored, and optimization studies have been carried out. Co-PTC in minute amounts exhibits an adsorption capacity of 79.3 % selectively for MG in 50 min. The kinetics and isotherm models governing the adsorption process are well investigated.