Adsorption Kinetic Studies Research Articles

The Synthesis of Functionalized W5O14 Nanorods for the Adsorption of Bismarck Brown R from Wastewater

In this research, a tungsten oxide was prepared via a green (biogenic) synthesis route where sodium tungstate dihydrate and Punica granatum peel extract were used as a precursor and a reducing/capping agent, respectively. The characterization of the prepared tungsten oxide was performed through various spectroscopic and microscopic techniques. The characterization results revealed the preparation of highly crystalline and nanorod-shaped (length = 123 nm and width = 31.3 nm) tungsten oxide with a probable chemical formula of W5O14. Various functional groups on the W5O14 surface were also reported. The prepared nanorods were further used for the removal of Bismarck Brown R (BBR) dye from water in a batch manner. By varying the dose of nanorods (0.5–3.0 g L−1), BBR solution pH (2−10), contact time (15–120 min), BBR concentration in solution (10–60 mg L−1), and temperature of BBR solution (30, 40, and 50 °C), the optimized condition for maximum adsorption efficiency was measured. The results revealed that 2.0 g L−1 amount of nanorods of tungsten oxide were used to remove ~98% of BBR dye from its 10 mg L−1 at 30 °C and 7.0 pH. The temperature-dependent adsorption data were fitted to different types of non-linear isotherm models (e.g., Langmuir and Freundlich) to assess the adsorption potential and adsorption mechanisms in relation to temperature impacts. The synthesized nano-adsorbent fits the Langmuir as well as the Freundlich isotherm model with a maximum adsorption capacity of 17.84 mg g−1. Pseudo-first-order, pseudo-second-order, and Elovich kinetic models were used for the study of adsorption kinetics. BBR adsorption onto the W5O14 nanorods follows the pseudo-second-order rates. The present adsorption is governed by physico-chemical adsorption with predominant chemical interactions.

A Comparative Kinetic and Thermodynamic Adsorption Study of Methylene Blue and Its Analogue Dye on Filter Paper

A Comparative Kinetic and Thermodynamic Adsorption Study of Methylene Blue and Its Analogue Dye on Filter Paper

Nanoparticle-assisted removal of EBT dye from textile wastewater: Towards sustainable Green gram seedling cultivation

Background: Wastewater refers to water of substandard quality that originates from urban and suburban regions. The water in question is used for cultivation in regions where there is a limited water supply for agricultural activities. The utilisation of marginal quality water for farming spans about 20 million hectares of land globally, with around 10% of the global population consuming food crops that have been irrigated with this kind of water. Methods: The CuONPs wassynthesizedby a chemical method, followed by their characterization using many methods including UV-Vis spect., FTIR, DLS, XRD, and SEM.The photocatalytic degradation of EBT dye and its adsorption kinetic studies were performed. Furthermore, impact of CuONPs, and wastewater on green gram seedlings under in-vitro conditions.Findings: The chemical methods effectively synthesized CuONPs as well as under ideal phytocatalytic condition CuONPsdegraded the EBT dye up to 51.09% in 5h of treatment.The inclusion of CuONPsat a dosage of 100 mg L−1 in the wastewater proceeded in a notable improvement in the green gram seed germination by 50%, and notable biometric profile as well as essential biomolecule (chlorophyll a&b, total soluble phenolics, and lycopene) profiles.

An environmentally friendly chitosan-loaded BiOCOOH/BiYO3 photocatalyst for efficient photocatalytic degradation of tetracycline.

In this work, the photocatalyst BiOCOOH/BiYO3/Chitosan (CS) was prepared by using CS as the carrier and adsorbent. The performance of the material was studied through the photocatalytic degradation of tetracycline (TC) in water. Theoretical calculations and experiments demonstrate that the formation of BiOCOOH/BiYO3 heterojunctions improves the separation of photogenerated carriers and the absorption of visible light by the material. The introduction of CS improves the difficulties in material recovery, demonstrating exceptional degradation ability for TC under the action of adsorption and photocatalysis. Adsorption kinetics studies indicate that the adsorption of TC by BiOCOOH/BiYO3/CS fits the pseudo-second-order model better, while the adsorption at different concentrations of TC is more suitably described by the Freundlich isotherm model. The synthesis of BiOCOOH/BiYO3/CS was confirmed by the analysis of XRD, XPS, and FTIR. UV-vis DRS showed that the synthesis of BiOCOOH/BiYO3/CS broadened the range of light absorbed by the material. The testing results of PL and transient photocurrent density indicate that BiOCOOH/BiYO3 exhibits a higher efficiency in separating photogenerated charge carriers. After 5cycles of reuse, the degradation efficiency can still reach 90% of the initial efficiency, indicating that CS-based photocatalytic composite catalysts have practical application potential in the field of water pollution treatment.

Urea‐Functionalized Degradable Material as an Efficient Adsorbent for Amphiphilic Dyes: Rhodamine B and Methylene Blue

AbstractHere we report urea‐functionalized material P‐UR1 invoked to analyze the dye adsorption property in aqueous medium. The unsaturated UR1 and the material P‐UR1 have been well characterized using different spectroscopic and analytical techniques. The hydrothiolated material exhibited viscoelasticity. The BET N2 sorption isotherm revealed P‐UR1 to exhibit porosity with a pore diameter of 15 nm and a surface area of 8.05 cm2/g. The kinetic adsorption studies reflect that the adsorption process follows pseudo‐second‐order model. Also, the adsorption isotherm analysis showed that the adsorption follows Langmuir adsorption isotherm. The material showed good response to recyclability for dye rhodamine B (RH B) in ethanol. The experimental observation was well supported by DFT calculation, where RH B + UR1x and MB + UR1x, x = 1, 2, complexes were examined. The interaction by the complexes RH B + UR12 and MB + UR12, both in air and solvent phase, indicates efficient interaction. The stabilization energy supports the efficient adsorption of the dyes rhodamine B (RH B) and methylene blue (MB) onto the material. Such urea‐derived functional material opens scope for textile industries.

Engineering iodine decorated azo-bridged porous organic polymer: A brilliant catalyst for the preparation of 2,4,6-trisubstituted pyridines

Iodine catalysis in organic transformations affords detailed coverage of recent advances in iodine chemistry. In this direction, the azo-bridged porous organic polymer bearing triazine and phloroglucinol moieties (Azo-POP1) was constructed via interfacial azo-coupling polymerization in water at room temperature. Considering its high specific surface area (153 m2.g-1) and pore size of 2.2 nm, karyotype-like morphology and considerable surface wettability, Azo-POP1 was successfully used as an adsorbent of I2. The adsorption kinetics studies show that the adsorption reaches equilibrium within one hour and increases with temperature. To our delight, this system (I2@Azo-POP1) was used as an irreplaceable heterogeneous catalyst for the synthesis of 2,4,6-trisubstituted pyridines via condensation reaction of diverse ketones with benzylamine and the following cyclization and cooperative vinylogous anomeric based oxidation. All the products were prepared in good yields under mild reaction conditions. Also, this attitude benefits from the environmentally friendly and recyclability of described catalyst.

Design and fabrication of nanocomposite adsorbents for dairy industry wastewater treatment

The dairy industry produces a significant volume of effluents that contain various pollutants, which causes environmental issues. In this study, the fabrication and performance of nanocomposite adsorbents incorporating activated carbon (AC), calcium alginate (CA), and nanosilica, as a simple, cost-effective, and eco-friendly approach to treat dairy wastewater, aiming to enhance food processing sustainability by reducing water consumption, minimizing wastewater, and supporting the Water-Food-Environment Nexus. The nanoparticles were synthesized using sand extraction in an environmentally friendly approach with a size of 30–45 nm. Several techniques such as X-ray fluorescence (XRF), X-ray diffraction (XRD), ultraviolet–visible spectroscopy (UV–VIS), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used to characterize the materials. Furthermore, the nanocomposite adsorbent performance and efficiency in removing chemical oxygen demand (COD) were assessed through batch experiments. The nanocomposite adsorbents’ optimal conditions were investigated through batch experiments, achieving a 99.7% COD removal in dairy wastewater treatment. The best results were obtained with a 4-h contact time, pH of 2, and nanosilica dosage of 10%, demonstrating the adsorbent’s high efficiency in organic pollutant removal. However, the adsorption isotherm, kinetic, and thermodynamic studies were carried out and the best-fitted models of isotherm, and kinetic models were Langmuir, and pseudo-second-order reaction, respectively. The thermodynamic reaction of this study is related to being endothermic.

Synthesis and characterization of corn cob activated carbon for Pb(II) adsorption with real-time monitoring using Internet of Things

Abstract Here, we investigate the adsorption of Pb(II) using AC derived from corn Rachis (RAC) with various carbonization temperatures: 500°C, 700°C, and 900°C using KOH solution as the activator. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed the presence of hydroxyl and carbonyl functional groups and optical-dielectric function change under the carbonization process. X-ray Diffraction (XRD) patterns confirmed the presence of (002) and (100) lattice planes, indicating a graphitic phase with amorphous area (X_a) domination. Scanning Electron Microscopy (SEM) images showed a honeycomb-like morphology, while Energy Dispersive X-ray (EDX) analysis indicated a carbon content of over 90%. Brunauer-Emmett-Teller (BET) analysis shows the high specific surface area of each sample (>1000 m2/g). The highest Pb(II) adsorption efficiency was achieved at 99.77%, with maximum performance at pH = 7.31, and temperature ~26.7℃, supported by the narrowing phonon vibration (Δ(LO-TO), lower electron loss function (ELF) shifts in wavenumber, higher X_a, and confirmed through adsorption kinetic and isotherm study. Here, we demonstrate a fresh methodology based on real-time monitoring using the Internet of Things of RAC as a promising adsorbent for Pb(II) removal with an adsorption capacity of 2.598 mg/g. In addition, the ability of adsorption results without stirring aids to determine their ability when applied to the environment has been studied.

Nanosilver-Biopolymer-Silica Composites: Preparation, and Structural and Adsorption Analysis with Evaluation of Antimicrobial Properties.

In this article, we report on the research on the synthesis of composites based on a porous, highly ordered silica material modified by a metallic nanophase and chitosan biofilm. Due to the ordered pore system of the SBA-15 silica, this material proved to be a good carrier for both the biologically active nanophase (highly dispersed silver nanoparticles, AgNPs) and the adsorption active phase (chitosan). The antimicrobial susceptibility was determined against Gram-positive Staphylococcus aureus ATCC 25923, Gram-negative bacterial strains (Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 700603, and Pseudomonas aeruginosa ATCC 27853), and yeast Candida albicans ATCC 90028. The zones of microbial growth inhibition correlated with the content of silver nanoparticles deposited in the composites and were the largest for C. albicans (14-21 mm) and S. aureus (12-17 mm). The suitability of the composites for the purification of water and wastewater from anionic pollutants was evaluated based on kinetic and equilibrium adsorption studies for the dye Acid Red 88. The composite with the highest amount of the chitosan component showed the greatest adsorption capacity (am) of 0.57 mmol/g and the most effective kinetics with a rate constant (log k) and half-time (t0.5) of -0.21 and 1.62 min, respectively. Due to their great practical importance, AgNP-chitosan-silica composites can aspire to be classified as functional materials combining the environmental problem with microbiological activity.

Efficient adsorptive removal of two anionic dyes (methyl orange and methyl red) with MOF‐525: Adsorption isotherms and kinetics studies

AbstractAdsorption is widely used to remove anionic and cationic dyes from wastewater because of its economical and high efficiency. Metal‐organic frameworks (MOFs), as a kind of adsorbent, have attracted great attention due to the large surface area, adjustable pore size, and high stability. In this study, a Zr‐MOF, named MOF‐525, was synthesized by using solvothermal method, and the adsorption performances of MOF‐525 on two anionic dyes (methyl orange, MO and methyl red, MR) were investigated. Results showed that the obtained MOF‐525, with the specific surface area of 2,613.91 m2 g−1, the total pore volume of 1.20 cm3 g−1, and the average pore size of 1.84 nm, exhibited high adsorption capacities for both MO and MR. The optimal pH value for MO and MR adsorption were 3.0 and 4.0, with the adsorption capacity of 854.30 and 629.67 mg g−1, respectively; in addition, the adsorption capacities for both MR and MO were increased with the increasing of SO42− concentration. The adsorption kinetics, isotherms, and thermodynamics results indicated the pseudo‐second‐order model and Langmuir (as well as Freundlich) could describe the adsorption processes of MOF‐525 well, and the adsorption processes for both MO and MR were spontaneous exothermic reactions. Besides, the reusability experiment demonstrated that MOF‐525 had significant adsorption capacity and good reusability for MR. In conclusion, the possible adsorption mechanisms of anionic dyes by MOF‐525 involved hydrogen bonding, electrostatic attraction, and π‐π interaction. These results illustrated that MOF‐525 might be a potential adsorption material for anionic dyes removal from wastewater.

Remediation of rhodamine B dye from aqueous solution by alkali and acid treated casuarina seed powder as low-cost adsorbent: adsorption dynamics, kinetic and thermodynamic studies

Remediation of rhodamine B dye from aqueous solution by alkali and acid treated casuarina seed powder as low-cost adsorbent: adsorption dynamics, kinetic and thermodynamic studies

Waste biomass-based graphene oxide decorated with ternary metal oxide (MnO-NiO-ZnO) composite for adsorption of methylene blue dye

In this study, a novel approach for the removal of methylene blue (MB) dye is effectively illustrated by using biomass based composite adsorbent. The investigation employed areca nut husk (AH) to produce graphene oxide (GO) by a single step calcination method. Thereafter, AH-GO was incorporated by using ternary metal oxide (TMO) via hydrothermal treatment. The developed AH-GO@MnO-NiO-ZnO composite was characterized by various analytical techniques, including FT-IR, XRD, FESEM, HRTEM, BET surface area and Raman spectroscopy which exhibited promising properties for dye adsorption. To study the adsorption efficiency of prepared composite, optimization experiments were performed for adsorbent dose, initial dye concentration and contact time. The optimized parameters during adsorption phenomenon were found to be 0.5g/L of dose, 20mg/L of initial concentration and 180min of time exhibiting removal efficacy of 93.05 ± 0.93%. Moreover, adsorption isotherm and kinetic models were analysed to explore the adsorption behaviour of AH-GO@MnO-NiO-ZnO towards MB dye. The adsorption isotherm and kinetic studies followed Langmuir isotherm model and pseudo-second-order (PSO) model respectively. AH-GO@MnO-NiO-ZnO has demonstrated a maximum adsorption capability of 127.06mg/g. These findings collectively underscore the potential of AH-based adsorbent as a viable, inexpensive, and environment friendly for the treatment of wastewater contaminated with MB dye.

Effects of particle size and aging on heavy metal adsorption by polypropylene and polystyrene microplastics under varying environmental conditions

Microplastics have become a major environmental issue because of their widespread presence and tendency to adsorb heavy metals, which can have harmful effects on aquatic ecosystems and human health. The present study investigates the adsorption mechanisms of Pb2+ and Cu2+ ions on both pristine and artificially aged microplastics (MPs) made of polystyrene (PS) and polypropylene (PP). Furthermore, the influence of MP size on the adsorption capacity under different environmental conditions was evaluated. According to the characterization of MPs, aging leads to physical damage and an increase in the number of oxygen-containing functional groups on their surface. The experimental results highlight the significantly higher adsorption ability of smaller and aged MPs compared with that of pristine MPs for both the heavy metal ions. The pseudo-second-order equation provided a better fit for the adsorption kinetics study (R2 = 0.95), suggesting that chemisorption governs the rate-limiting phase in the adsorption mechanism on the MP surfaces. The concordance between the adsorption isotherm model and Freundlich model (R2 > 0.95) indicated a predominance of multilayer adsorption. The environmental factors such as pH, humic acid, temperature, and SO42- concentration significantly affected the adsorption of Pb2⁺ and Cu2⁺ onto PP and PS MPs. These variables play a crucial role in determining the nature of the interactions between heavy metal ions and the microplastic particles under diverse environmental conditions. Electrostatic interactions, surface complexation and van der Waals forces were identified as two factors that could either improve or diminish the metal ion adsorption capacity of MPs.

Scalable Melt Polymerization Synthesis of Covalent Organic Framework Films for Room Temperature Low-Concentration SO2 Detection.

The development of highly efficient sensors for low-concentration SO2 at room temperature is important for human health and fine chemistry, but it still faces critical challenges. Herein, a scalable olefin-linked covalent organic framework (COF) with an ultramicroporous structure and abundant binding sites is first developed as the SO2 sensing material. The COF can adsorb SO2 of 220 cm3/g at 1 bar and 40 cm3/g at 0.01 bar and 298 K, surpassing all reported COFs. The computational and kinetic adsorption studies deeply unveil the selective adsorption mechanism for low-concentration SO2. Furthermore, the multicomponent gas mixture breakthrough experiments confirm that the COF can specifically capture low-concentration (2000 ppm) SO2. We innovated a melt polymerization technology to fabricate COF films with adjustable substrates and film thicknesses. COF films are directly grown on the interdigital electrodes to prepare the SO2 sensor device, which possesses a low detection limit (86 ppb) and excellent selectivity for SO2 in the presence of 10 other potentially interfering gases. Compared to other reported SO2 sensors, its overall performance is among the top. Prominently, the sensor maintains a stable output signal for more than two months, and recovery can be easily achieved by simply purifying nitrogen at room temperature without heating. This study marks the first use of COFs for SO2 sensing, opening new possibilities for COFs in the detection of low-concentration toxic gases and manufacturing gas sensor devices.

Remediation of leached iron ions from real dip-coating waste solution using biodegradable hydrogels prepared by gamma rays

Dip-coating is one of the most commercially applied coating processes for metals. The excess of iron ions in the dipping solution, which is formed as a result of repeated dipping in the same bath several times, reduces the efficiency of the solution. In this research, polymeric hydrogel based on tannic acid (PEG/PAm/CMC)/TA via gamma irradiation was prepared as an efficient and clean method to remove the excessive content of Fe ions leached in the dipping precursor solution. Swelling characteristics and gelation content of the prepared samples were studied. The best copolymer composition was (1:5:1:1) wt% for (PEG/PAm/CMC)/TA, respectively with a total polymer concentration of 30 wt%. Change in the chemical and physical structures of the prepared hydrogel was studied using FTIR and XRD. The topographic surface of the prepared hydrogel and distribution of adsorbed Fe ions were studied using an SEM and EDX respectively. The adsorption kinetics study reveals that the chemical reaction follows second-order reactions. The linearity in the Freundlich adsorption model reveals a maximum multilayer adsorption capacity of (230) mg/g for the (PEG/PAm/CMC)/TA hydrogel. The results also indicate that the biodegradability of the prepared hydrogels increases with CMC and TA contents. The investigations concluded that the prepared hydrogel could efficiently absorb the iron ions leaked from the dipping solution.

Production and characterization of biochar and modified biochars by carbonization process of bearberry (Arctostaphylos uva-ursi. L.): Adsorption capacities and kinetic studies of Pb2+, Cd2+ and rhodamine B removal from aqueous solutions

In this work, Bearberry (Arctostaphylos uva-ursi L.) leaves and twigs were used as novel biomass source for production of biochar and modified biochars (manufacturing of microporous and mesoporous carbons by physical and chemical activations, using CO2 and H3PO4) via one-step carbonization (800 °C) with excellent physicochemical properties, for effective removal of Pb2+ and Cd2+ ions, and synthetic dye (Rhodamine B - RhB) from aqueous solutions. Results showed that carbonized (BL-C) and physically activated carbons (BL-CO2) as microporous adsorbents (specific surface areas 219.0 m2/g and 305.5 m2/g) show remarkable removal efficiency of Pb2+ (99.8 % and 99.9 %, for BL-C and BL-CO2), while these adsorbents showed moderate affinity for Cd2+ elimination (53.5 % and 48.5 %). BL-H3PO4 as mesoporous adsorbent with lower specific surface and larger pores (90.2 m2/g with Dmax = 33.6 nm), shows very good removal efficiency of PhB (~ 87 %). It was found that physical adsorption occurs during RhB removal onto BL-H3PO4, where dominant mechanism represents film diffusion, with reduced boundary layer effect. Adsorption process takes place over π–π, hydrogen bonding and electrostatic interactions. Adsorption processes of Pb2+ and Cd2+ onto BL-CO2 and BL-C take place via physical and chemical adsorption, but with different type of mechanism, including combination of diffusion and chemisorption (increased effect of boundary layer) and intra-particle diffusion (greatly reduced boundary layer effect), respectively. A very interesting fact found in this study, is that metal oxide surfaces (as Cu2O, SiO2, ZnO present in activated carbons) exhibit an efficient binding towards cadmium, providing physisorption capability onto non-metallic graphene features.

One‐Step Green‐Synthesized UiO‐66‐NH2 /Alginate Composite Hydrogels with Improved Methylene Blue Adsorption

AbstractZirconium‐based metal‐organic frameworks (Zr‐MOFs) represent an important class of MOFs with high stability and outstanding properties, the green preparation and shaping of which are still challengeable works to hinder their real‐world applications. In this presentation, UiO‐66‐NH2 MOFs were in‐situ grown accompanied by alginate (Alg) hydrogelation under aqueous conditions, achieving UiO‐66‐NH2/Alg composite hydrogels. Relevant characterizations demonstrate the in‐situ generated UiO‐66‐NH2 MOFs were evenly distributed in hydrogel networks by attaching on Alg fiber surfaces. The network structure became denser, but both specific surface area and pore volume were augmented due to the presence of MOFs, which in turn increased active sites to interact with adsorbates. Thus, the adsorption capacity to methylene blue (MB) of composite hydrogels became higher with more dosage of MOF ligand, and the pH sensitivity of Alg adsorption to MB in the pH range of 4 to 10 was eliminated. Furthermore, the study of adsorption kinetics and isotherm reveals MB adsorption on the obtained hydrogels belong to rate controlling chemisorption mechanism. In summary, this manuscript presents a facile approach to realizing the green synthesis and shaping of Zr‐MOFs by one‐step compositing of UiO‐66‐NH2 with Alg‐based hydrogels in aqueous system, achieving MOFs‐based composite hydrogels with enhanced MB adsorption.

Magnetic activated carbonaceous materials from sugarcane bagasse: Preparation, characterization, and hexavalent chromium removal

The presence of hexavalent chromium (Cr (VI)) in effluents remains a global concern due to its toxic properties. Even though adsorption has been employed for its removal from water, developing sustainable materials with higher adsorption capacities is still pivotal to tackling such contamination. In this study, two magnetic carbons (MC) were produced by hydrothermal carbonization (HTC) of sugarcane bagasse in the presence of iron (III) nitrate at 230 and 270 °C. Both MCs were thermochemically activated at 500 and 700 °C using KOH (1:2; w:w). The materials were characterized in terms of composition, structure, morphology, texture, and surface properties and then evaluated in adsorption studies of Cr (VI). After HTC, some iron phases such as α-Fe2O3, γ-Fe2O3, and Fe3O4 were observed, while thermochemical activation additionally revealed Fe0 and Fe4[Fe(CN)6]3. Activation increased the amount of meso- and macropores, specific surface area, pHzpc, surface hydrophilicity, and carbon and nitrogen contents. The adsorption kinetics study indicated that the pseudo-second-order model describes better the behavior of the materials. The investigation of adsorbent dose showed that doses below 1.00 g L−1 were more efficient in Cr (VI) removal. MC-230 and MC-270 thermochemically activated at 700 °C exhibited the highest Cr (VI) adsorption capacities (10.5 and 15.5 mg g−1, respectively). Therefore, the improved adsorption capacity for Cr (VI) of the materials thermochemically activated at 700 °C was mainly due to their enhanced textural properties.

Evaluation of a novel activated carbon/graphene oxide as an efficient composite adsorbent for the removal of herbicide 2,4-Dichlorophenoxyacetic acid: Adsorption isotherm and kinetics study

Thysanolaena maxima-derived activated carbon/graphene oxide (TMAC/GO) composite was synthesized through a one-step mixing process via ultrasonication and used as an adsorbent for the removal of 2,4-Dichlorophenoxyacetic acid (2,4-D) herbicide from solution. Various analytical techniques, including Fourier-transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy-energy dispersive X-ray spectroscopy (FESEM-EDX), X-ray diffractometer (XRD), Brunauer, Emmett, and Teller (BET) surface area analyzer, and Transmission electron microscopy (TEM) were employed to characterize the synthesized composite. Results showed that the TMAC/GO had a porous structure with a large surface area of 960 m2/g, an average pore diameter of 2.658 nm, and a total pore volume of 0.6372 cm3/g. A series of batch experiments were conducted for different adsorption parameters, which include TMAC/GO dosage (0.05–0.25 g/L), initial concentration (50–300 mg/L), pH (2–12), contact time (20–140 mins), and temperature (298–398 K). Adsorption thermodynamics, isotherm models, and kinetics were employed to understand the adsorption mechanism. The composite showed good adsorption ability with the Langmuir maximum adsorption capacity of 98.469 mg/g. When compared with TMAC, the composite exhibited higher removal efficiency under the same dosage, concentration, and temperature with variations in pH and time. The pseudo-second-order kinetics model justified the experimental results with an R2 value of 0.997. Furthermore, the composite displayed good reusability performance up to 5 cycles. These findings, along with the cost-effectiveness of the material and its selectivity towards the herbicide, suggest its practical importance for water decontamination.

The Adsorption Isotherm and Kinetics Studies of Cu(II) and Cr(III) Metal Ions from Aqueous Solutions on Activated Biosorbent of Coffee Pulp Waste

The Adsorption Isotherm and Kinetics Studies of Cu(II) and Cr(III) Metal Ions from Aqueous Solutions on Activated Biosorbent of Coffee Pulp Waste