Adsorption Of Rhodamine Research Articles

Optimization, Kinetic and Thermodynamic Study of Rhodamine B Removal by Zinc Chloride-activated Arachis hypogaea (Groundnut Husk) biochar

Adsorption of dye from industrial effluent before discharge into the environment has become a major challenge to the food, pharmaceutical, textile, photographic and cosmetic industries. This has led scientists to the search for suitable green solutions. Carbonized and zinc chloride activated Arachis hypogaea (groundnut husk) in a 1:1 ratio was used as an adsorbent for the removal of Rhodamine B from aqueous solution. The adsorbent was characterized by ash content, bulk density, moisture content, pH, Iodine number, surface area and functional group analyses. Key parameters such as initial pH, initial concentration of Rhodamine B dye, temperature and contact time were investigated. The equilibrium data obtained were correlated with Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms. It was found that both the Freundlich and Langmuir isotherms fit well to the data. The Langmuir isotherm model best describes the uptake of Rhodamine B onto zinc chloride activated groundnut husk biochar with R2 > 0.997. Maximum Rhodamine B. dye removal was observed at a pH of 11.0, with an adsorbent dosage of 1.0 g, a contact time of 125 min, an initial dye concentration of 20 mg/L and a temperature at 315 K. The efficiency of zinc chloride activated groundnut husk biochar for Rhodamine B removal was 99.55% for dilute solutions at 50 g/L. The Fourier Transform Infrared (FTIR) spectra recorded before and after activation showed the numbers of functional groups available for Rhodamine B. molecules to bind onto in the studied adsorbent. The kinetic data were best described by the pseudo-first-order and pseudo second-order models, while the thermodynamic studies indicated a spontaneous and endothermic nature in the adsorption of Rhodamine B by the zinc chloride modified groundnut husk. This research clearly details an innovative approach to utilizing carbonized and zinc chloride-activated Arachis hypogaea (groundnut husk) as an eco-friendly adsorbent for the removal of Rhodamine B from industrial effluents.

Synthesis and characterization of Selenicereus undatus extract mediated nano-Bi2O3 and its application in the adsorption of Rhodamine B dye

Betacyanins (BC) are reddish-purple pigments widely found in the peels of white-fleshed dragon fruit (Selenicereus undatus) and peels and pulps of red-fleshed dragon fruit (Selenicereus costaricensis). BC pigments are good anti-oxidants that inhibit the formation of reactive oxygen species (ROS) in plants and thereby promote the reduction of metal ions to zero-valent metals. It also acts as a good stabilizing and capping agent in the synthesis of nanoparticles. Hence, this research aims to extract, and quantize the content of BC from the peels of Selenicereus undatus, to fabricate betacyanin-rich- Selenicereus undatus (SU) modified bismuth oxide nanoparticles (Bi2O3 NPs) and characterize using UV-Vis, FTIR, XRD, SEM, EDAX, and BET. The quantity and stability of the betacyanin are optimized using various parameters like time, temperature, solvent ratio, pH, etc., through a UV-Vis spectrophotometer at 538 nm. Synthesized SU-Bi2O3 NPs aim to alleviate synthetic dye contaminants through adsorption- an efficient route for water remediation. The nano-adsorbent Bi2O3 NPs showed an increase in dye adsorption with an increase in reaction time, temperature, and Bi2O3 NPs dosage, enabling efficient removal of dyes such as Rhodamine B (RhB) dyes.

Reduction of 4-Nitrophenol and Adsorption of Rhodamine B Using Reduced Graphene Oxide-Copper Sulfide Nanomaterial

Reduction of 4-Nitrophenol and Adsorption of Rhodamine B Using Reduced Graphene Oxide-Copper Sulfide Nanomaterial

In-Situ Hydrothermal Fabrication of ZnO-Loaded GAC Nanocomposite for Efficient Rhodamine B Dye Removal via Synergistic Photocatalytic and Adsorptive Performance.

In this work, zinc oxide (ZnO)/granular activated carbon (GAC) composites at different ZnO concentrations (0.25M-ZnO@GAC, 0.5M-ZnO@GAC, and 0.75M-ZnO@GAC) were prepared by an in-situ hydrothermal method and demonstrated synergistic photocatalytic degradation and adsorption of rhodamine B (RhB). The thermal stability, morphological structure, elemental composition, crystallographic structure, and textural properties of developed catalysts were characterized by thermal gravimetric analysis (TGA/DTG), scanning electron microscopy equipped with energy dispersive-x-ray (SEM-EDS), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) analysis. The successful loading of ZnO onto GAC was confirmed by SEM-EDS and XRD analysis. The BET surface areas of GAC, 0.25M-ZnO@GAC, 0.5M-ZnO@GAC, and 0.75M-ZnO@GAC were 474 m2/g, 450 m2/g, 453 m2/g, and 421 m2/g, respectively. The decrease in GAC could be attributed to the successful loading of ZnO on the GAC surface. Notably, 0.5M-ZnO@GAC exhibited the best photocatalytic degradation efficiency of 82% and 97% under UV-A and UV-C light over 120 min, attributed to improved crystallinity and visible light absorption. The photocatalytic degradation parameters revealed that lowering the RhB concentration and raising the catalyst dosage and pH beyond the point of zero charge (PZC) would favor the RhB degradation. Photocatalytic reusability was demonstrated over five cycles. Scavenger tests revealed that the hydroxyl radicals (•OH), superoxide radicals (O2-•), and photoinduced hole (h+) radicals play a major role during the RhB degradation process. Based on the TOC results, the RhB mineralization efficiency of 79.1% was achieved by 0.5M-ZnO@GAC. Additionally, GAC exhibited a strong adsorptive performance towards RhB, with adsorption capacity and the RhB removal of 487.1 mg/g and 99.5% achieved within 90 min of equilibrium time. The adsorption characteristics were best described by pseudo-second-order kinetics, suggesting chemical adsorption. This research offers a new strategy for the development of effective photocatalyst materials with potential for wider wastewater treatment applications.

Synthesis and Characterization of Silica-Biochar Composite as Rhodamine B Dye Adsorbent

Composites are synthesized by combining different materials, resulting in properties suitable for use as adsorbents due to the combination of pores and functional groups within the constituent materials. This study developed a silica-biochar composite to serve as an adsorbent for rhodamine B dye, utilizing silica derived from red mud and biochar obtained from oil palm empty fruit bunches (OPEFB). This research focused on analyzing the characteristics and effectiveness of the composite as an adsorbent by varying its composition. Silica from red mud exhibited a purity of 80.05% and possessed silanol (Si-OH) and siloxane (Si-O-Si) functional groups on its surface, whereas biochar from OPEFB had a carbon content of 95.91% and included functional groups such as -OH, C=O, C=C, C-H, and C-O. The combination of silica and biochar yielded a composite surface consisting of -OH, C=O, C=C, C-O, C-H, and Si-O-Si functional groups. The silica-biochar composite demonstrated a greater surface area than its individual components, with silica at 69.824 m²/g and biochar at 95.452 m²/g. The composite with a 1:2 (% w/w) ratio exhibited the largest surface area at 102.371 m²/g, achieving a maximum adsorption capacity of 1.550 mg/g and an efficiency of 88.463%. The adsorption process encompasses physical interactions via pore diffusion and chemical interactions through functional groups.

Adsorption of Rhodamine B, methyl Orange, and phenol separately in aqueous systems by magnetic activated carbon: Optimization by central composite design

In the current study, a novel magnetic activated carbon was synthesized for efficient removal of both anionic methyl orange, cationic Rhodamine B and Phenol fromcontaminatedwater. The adsorbent was characterized by different technique. The investigation of the adsorption properties of magnetic activated carbon was studied by central composite design (CCD) coupled with response surface methodology (RSM). The optimal conditions were established as follows: dye concentration of Coat 30 mg/L, dosage at 0.8 g/L, and pH of the adsorbate solution adjusted to 4.5. The different kinetic and isotherm models were applied to fit the experimental results, and it was observed that the Pseudo-second-order kinetics and Langmuir adsorption isotherm were the best-fitted models. The maximal monolayer adsorption capacities of the adsorbent were found to be 101, 218 and 135 mg/g for phenol, methyl orange, and rhodamine B, respectively. The synthesized MAC had outstanding durability and reusability, as seen by the removal rate that persisted over 80 % following four adsorption-oxidation cycles.The advantages of facile synthesis, cost-effectiveness, non-toxicity, strong adsorption capabilities for methyl orange, Rhodamine B and Phenol, and easy separability with an external magnetic field make magnetic activated carbon novel.

One step synthesis of cerium-based porous carbon microsphere by ultrasonic spray pyrolysis and its adsorption of rhodamine B

Cerium-based porous carbon microsphere (Ce/PCM) was synthesized by one step ultrasonic spray pyrolysis (USP), and the structure was analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) and Raman spectrometer. Furthermore, the adsorption performance of Ce/PCM was tested by Rhodamine B. (Rh B). The characteristic’s results showed the structure and specific surface area of Ce/PCM were affected by the pyrolysis temperature, and 800-Ce/PCM had the maximum specific surface area as 472.9 m2·g−1. The adsorption evaluation showed that 800-Ce/PCM had the best removal efficiency, and the maximum adsorption capacity was as high as 508.2 mg·g−1. The results suggested the adsorption kinetics of Ce/PCM for Rh B follows pseudo second-order dynamics and Freundlich model, which indicated that the adsorption process includes chemical adsorption and multilayer adsorption. Kinetic thermodynamic studies proved the absorption was endothermic reaction. The analysis of absorption mechanism indicated that the removal mechanism mainly includes pore filling, hydrogen bonding and surface adsorption.

Preparation of cellulose adsorbent based on banana peel waste (Musa paradisiaca): Green activation and adsorption of Rhodamine B from the aquatic environment

In this study, the successful development of an adsorbent based on banana peel (Musa paradisiaca) activated using lime juice (Citrus aurantifolia) has been reported. The physicochemical parameters of the adsorbent were investigated using an XRD instrument, which showed that the crystal structure of the banana peel (BP) and green activated banana peel (ABP) had a 2θ peak between 18 and 25°, which is the typical peak of cellulose 1. The FTIR spectra showed that green activation of BP specifically changes BP's structure. A bonded O–H group is seen at a wavelength of 3300 cm−1, a peak at 2921 cm−1 is assigned to C-H stretching, the peak at 1615 cm−1 is typical for CO stretching, the peak at 1598 cm−1 is the characteristic peak of C-C aromatic skeletal vibration and the peak at 1034 cm−1 is from the C-O-C and C-C stretch. The FESEM image showed that the morphology of ABP looks rougher and more porous than the morphology of BP. BET-BJH data showed the weak interactions during adsorption can lead to a higher adsorption capacity because these interactions are reversible. The adsorption of RhB with a maximum initial concentration was 70 mg L−1 on 0.2 g of ABP at pH 6, in 10 min at 323 K. The adsorption mechanism followed a pseudo-second-order kinetic model, while the isotherm adsorption followed the Freundlich model. Thermodynamic analysis revealed that the adsorption process is exothermic and spontaneous, as indicated by the enthalpy value of −25.342 kJ mol−1 and entropy of 0.572 kJ mol−1. In summary, this adsorbent can effectively eliminate coloured pollutants from wastewater.

A Study on the Adsorption of Rhodamine B onto Adsorbents Prepared from Low-Carbon Fossils: Kinetic, Isotherm, and Thermodynamic Analyses.

The aim of this study was to obtain a series of activated carbon samples by the chemical activation of low-rank coal. The precursor was impregnated with a NaOH solution. Activated carbons were characterized by determining their textural parameters and content of surface oxygen functional groups and by using an elemental analysis. The carbons were tested as potential adsorbents for the removal of liquid pollutants represented by rhodamine B. The effectiveness of rhodamine B removal from water solutions depended on the initial concentration of the dye, the mass of rhodamine B, and the pH and temperature of the reaction. The isotherm examination followed the Langmuir isotherm model. The maximum adsorption capacity of the rhodamine B was 119 mg/g. The kinetic investigation favored the pseudo-second-order model, indicating a chemisorption mechanism. The thermodynamic assessment indicated spontaneous and endothermic adsorption, with decreased randomness at the solid-liquid interface. The experiment revealed that a 0.1 M HCl solution was the most effective regenerative agent.

Quasi-2D MIL-100 (Fe) synthesis via benzene-1,3,5-tricarboxylic acid self-assembly: organic dye adsorption at room temperature with dramatically enhanced kinetics.

Amid increasing environmental pollution, two-dimensional materials have played pivotal roles in environmental remediation. However, two-dimensional metal-organic frameworks (2D-MOFs) have yet to be thoroughly explored. This study introduces a novel approach to synthesize 2D-MOFs, particularly focusing on MIL-100-(Fe), for the adsorption of emerging organic dyes. By harnessing the self-assembly of benzene-1,3,5-tricarboxylic acid (BTC), we formed thin solid interfaces of BTC as building blocks to control the growth of MIL-100-(Fe). This resulted in quasi-2D structures that showed over a 35% increase in adsorption capacity and a 5.5-fold increase in the adsorption kinetics of Rhodamine B removal compared to their 3D counterparts. This new method overcomes traditional synthesis limitations, offering a replicable and high-yield procedure for 2D-MOF synthesis. Compared to its three-dimensional counterpart (3D MIL-100 Fe), the prepared adsorbent exhibited remarkably higher efficacy in the adsorption of Rhodamine B, with high structural stability and recyclability. The prepared adsorbent shows over 99% adsorption within 90 minutes for initial dye concentrations of 1-40 mg L-1via the Langmuir adsorption mechanism and pseudo-second-order kinetics. Our research pioneers a method for the synthesis of quasi 2D-MIL-100-(Fe), laying the groundwork for fabricating other 2D-MOF structures, particularly those based on carboxylic acids.

Adsorption of Rhodamine G from Aqueous Solutions onto Particles of Few-Layer Graphene Prepared by Self-Propagating High-Temperature Synthesis

The ability of few-layer graphene prepared by self-propagating high-temperature synthesis to adsorb Rhodamine G was studied. The dependences of the sorption capacity of few-layer graphene particles on the Rhodamine G concentration in aqueous solution, solution temperature, and adsorption time were determined. The adsorption of Rhodamine G on the surface of few-layer graphene is satisfactorily described by the Langmuir and Freundlich models. The process occurs under mixed diffusion control and can be described by a pseudo-second-order rate equation.

Preparation of sucrose-derived activated carbon in one pot with desirable hierarchically porous structure for efficient dyes removal

Sugar is an excellent raw material for activated carbon preparation because of its wide availability, sustainability, and low mineral content. Herein, we developed an easy method for preparing sucrose-derived activated carbon (SAC) with desirable hierarchically porous structures by combining the foaming of molten sucrose, dual-templating (K2C2O4·H2O and CaCO3), and sequential etching by dual-templating activators at elevated temperatures. As an adsorbent, SAC–800 has a high specific surface (1594 m2/g), with rich both micro- and mesopores (microsurface vs external surface area is 812 and 782 m2/g). As a result of its desirable hierarchically porous structures, it adsorbs dyes fast and efficiently, attributed to the rich specific surface area that favors adsorption capability and pore size distribution that affects mass transport and adsorption speed. The adsorption for Rhodamine B and Congo Red is spontaneous and endothermic process. The adsorption capacities reach 357 and 780 mg/g for Rhodamine B and Congo Red, respectively, while the rate constants for adsorption (ka) and desorption (kd) for Rhodamine B are 4.23 × 10–3 L/(mg·min) and 0.12 L/min, and 1.02 × 10–3 L/(mg·min) and 5.6 × 10–3 L/min for Congo Red. With the easy preparation procedure and the desirable hierarchically porous structures, sucrose-derived activated carbons are promising candidates for potential practical applications.

Advanced Equilibrium Studies for the Synergetic Impact of Polyaniline on the Adsorption of Rhodamine B Dye by Polyaniline/Coal Composite.

The synergetic improvement effect of the polyaniline (PANI) hybridization process on the adsorption of rhodamine B dye (RB) by PANI/coal hybrid material (PANI/C) has been evaluated using both traditional equilibrium modeling and advanced isotherm investigations. The composite was prepared by polymerizing polyaniline in the presence of coal fractions with a surface area of 27.7 m2/g. The PANI/C hybrid has an improved capacity to adsorb RB dye (423.5 mg/g) in comparison to coal particles (254.3 mg/g). The maintained increase in the elimination properties of PANI/C has been illustrated using the steric characteristics of active site density (Nm) as well as the total number of adsorbed RB on a single active site (n). However, the incorporation of PANI did not yield any substantial impact on the existing active sites' quantity, but the hybridization processes greatly influenced the selectivity and affinity of each active site, in addition to the aggregation characteristics of the dye as it interacts with the composite's surface. Whereas raw coal can only adsorb three molecules of RB, each active site throughout the PANI/C surface can adsorb approximately eight RB molecules. This is also evidence of RB dye adsorption in a vertical arrangement, which involves multimolecular processes. The Gaussian energy (4.01-5.59 kJ/mol) and adsorption energy (-4.34-4.68 kJ/mol) revealed the controllable impact of physical mechanisms. These mechanisms may include van der Waals forces, dipole-dipole interactions, and hydrogen bonds (<30 kJ/mol). The thermodynamic functions, such as enthalpy, internal energy, and entropy, that have been assessed provide evidence supporting the exothermic and spontaneous nature of the RB uptake processes by PANI/C.

An anionic In(III)-MOF for efficient adsorption of CO2 from CO2/N2 mixture and dye removal

Efficient adsorption of CO2 and dye molecules is crucial for reducing carbon emission and environmental pollution. Metal-Organic Frameworks (MOFs) are considered to be the ideal candidates for gas adsorption material because of their designability. In this work, a new In(III)-MOF (HBU-22) was synthesized by the reaction of a tetracarboxylic acid ligand (H4L, 9,9′-bicarbazole-3,3′,6,6′-tetracarboxylic acid) with In3+ ions, which shows a three-dimensional (3D) coordination network. The saturated adsorption capacity of CO2 and N2 are 21.11 cm3‧g−1 and 0.66 cm3‧g−1 at ambient condition (298 K, 100 kPa). And the higher IAST selectivity of CO2/N2 (v/v, 15:85) reaches 347.37, exceeding that of most MOFs. Furthermore, it can also capture C2H2 with the maximum uptake of 42.80 cm3 g−1. More interestingly, HBU-22 as an anionic framework, which can selectively adsorb Rhodamine B (RhB) within 250 s with the maximum adsorption capacity of 105.04 mg‧g−1. Further studies show that higher gas adsorption capacity is mainly related to the larger Qst of the gas, while its adsorption of Rhodamine B (RhB) is mainly due to ion exchange mechanism.

Adsorption of Rhodamine b dye onto novel Biochar: Isotherm, Kinetic, thermodynamic study and antibiofilm activity

Wastewater pollution from organic dyes has been a serious and increasing environmental problem. The present work aims to synthesize and characterize biochar (BC) from shrimp shells for application as a biosorbent in the Rhodamine B (RhB) dye removal. Central Composite Rotational Design (CCRD 22) was used to determination of the ideal condition by adsorption process and BC was characterized by X-ray Diffraction (XDR), N2 porosimetry, zero charge point (pHZCP) and Scanning Electron Microscope (SEM). The toxicity was measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) and 2,7 Dichlorofluorescein Diacetate (DCFH-DA) assay in 293 T, HaCat, and MDBK cell lines, and antibiofilm activity was carried out against P. aeruginosa, A. baumannii, S. epidermidis and E. coli strains. BC showed an irregular morphology (semi-cubic and plates), mesoporosity (Dp ∼ 12.3 nm), pore volume around 0.43 cm3 g−1, the surface area of the 101 m2/g and pHZCP = 7.34. The best experimental fit for the adsorption data was Freundlich isotherm (equilibrium) and pseudo second-order (PSO) (kinetic model) indication a chemisorption process with a maximum adsorption capacity of 350.55 mg g−1 with 72.34 % of RhB removal (pH = 9, T = 298 K and [BC] = 4.5 g/L). Moreover, a thermodynamic study confirmed a spontaneous process (ΔG < 0), endothermic (ΔH = 64.76 kJ mol−1) and with an increase in system randomness indicating structural alterations of the BC surface and the RhB adsorbed (ΔS > 0). Regarding the BC recycling, there was a reduction from 72.10 % (349.38 mg g−1) to 46.32 % (223.38 mg g−1) after V cycles. BC showed biocompatibility (except in the higher concentration) and important antibiofilm activity of 87.5 % (P. aeruginosa), 53.12 % (S. epidermidis), 68.93 % (A. baumannii) and 51.7 % (E. coli) to 125 µg mL−1. Therefore, it was possible to synthesize and characterize an alternative biosorbent from shrimp shell waste with high adsorption capacity, meeting the circular economy for wastewater treatment.

Tailoring Homogeneous Hydrogel Nanospheres by Facile Ultra-Sonication Assisted Cross-Linked Copolymerization for Rhodamine B Dye Adsorption.

The present paper describes the design of shape-oriented hydrogel nanospheres using a facile ultrasonication-supported crosslinked copolymerization technique. The effect of variable monomer concentration on the homogeneity of hydrogel nanospheres was investigated. The chitosan-cl-poly(MMA) hydrogel nanospheres were well characterized using various techniques such as FTIR, XRD, TGA, SEM, and TEM. The chitosan-cl-poly(MMA) hydrogel nanospheres were studied for their swelling behavior and could potentially be used as a novel adsorbent for rhodamine B dye remediation from aqueous media. The study found that utilizing chitosan-cl-poly(MMA) nanohydrogel spheres at the optimal pH 5 increased RhB dye adsorption capacity from 7.9 to 17.8 mg/g (pH 2 to 5), followed by a slight reduction. Furthermore, when nanohydrogel concentration increased, adsorption capacity dropped from 18.03 to 2.8 mg/g, but adsorption percentage climbed from 90.2% to 97.8%. At an initial dye concentration of 140 mg/L, rhodamine B adsorption achieved 204.3 mg/g in 60 min. The rhodamine B dye adsorption study includes adsorption kinetics, isotherm, and thermodynamics analyses. The interpretation of the adsorption study revealed that Langmuir isotherms fit best with a qmax value of 276.26 mg/g, which is in close approximation with the experimental value, whereas pseudo-second-order kinetics explains the adsorption process rate. The interaction of RhB dye with chitosan-cl-poly(MMA) hydrogel nanospheres involves multiple forces such as electrostatic interactions, hydrogen bonding, van der Waals forces, etc.

Adsorption of rhodamine B by Pleurotus eryngii: growth, modification, characterization, adsorption isotherms, kinetics and thermodynamics

Adsorption of rhodamine B by Pleurotus eryngii: growth, modification, characterization, adsorption isotherms, kinetics and thermodynamics

Effect of Particle Size and Mass of Longan Peel (Euphoria Longan L.) as Adsorbent on The Adsorption of Rhodamine B and Methylene Blue Dyes Using the Column Method

Dyes are a mixture of organic compounds that are synthesized in complex forms and are often used in the process of coloring products in various types of industries, so that this complex structure will be difficult to decompose naturally. Therefore, this dye will accumulate in the liquid waste. The accumulation of these dyes will cause harm to living things and the surrounding environment. Therefore, an effective method is needed to overcome this problem, a method that can be used to reduce the dye content in a simple and environmentally friendly way such as the adsorption method. In this study, the adsorption method using a column was used to absorb dyes from the cationic group, namely methylene blue and rhodamine B with adsorben derived from longan peel waste. In this study, the results obtained were the identification of longan peel containing several functional groups, namely O-H, C-H, C=O, -C-NO2, C=C, C-O-C, and C-N derived from alcohol, carboxylic acid, ester, ether, aromatic nitro compounds, and amines. By using a adsorbent particle size of 106 µm, it can absorb methylene blue and rhodamine B at 30.31 mg/g and 28.28 mg/g, respectively. The absorption of methylene blue with 0.1 gram of adsorbent resulted in an absorption capacity of 59.97 mg/g while 0.2 gram of adsorbent could absorb rhodamine B of 32.40 mg/g.

Synergic binding of rhodamine-B and heavy metal ions onto polyethyleneimine grafted freeze-dried chitosan/epichlorohydrin composite beads and possible mechanism

This paper reports a synergic binding technique of dye and cadmium/lead ions onto freeze-dried modified chitosan beads (GCCS), in this work modified chitosan beads was applied in binary solution. Chitosan beads (CS) composite was produced and polyethyleneimine was grafted onto the backbone of the developed composite. The beads were analyzed utilizing different analytical techniques such as Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscope (SEM). The model applied in pH equilibrium was found to justify the adsorption of pollutants onto the adsorbent. The model was established from 2 equilibrium calculations, one justifying the acid-base attributes of the modified beads, the other elucidating the adsorption of the adsorbates onto the beads, and a mass balance of the various arrangement of nitrogen in the adsorbent. The excellent fit of the Pseudo-second order and intra-particle diffusion kinetic model shows that chemical binding might be the rate-limiting step. The adsorption isotherms were well represented by the Langmuir and Temkin models at a temperature of 45 °C. The maximum binding capacities (Qmax) from the Langmuir model were observed to be 390, 315 and 278 mg/g for the adsorption of dye, lead and cadmium ions respectively`. However, it was found to be higher in the binary system with the same applicable conditions. The correlation was analyzed utilizing various models and lines of best fit were obtained. Synergic effect was observed from the experimental results acquired from the adsorption of Rhodamine B (RHB) and adsorbates. These findings show the formation of fresh binding sites during simultaneous binding process.

Adsorption of Rhodamine B and Pb(II) from aqueous solution by MoS2 nanosheet modified biochar: Fabrication, performance, and mechanisms

Mediated by polydopamine, MoS2 nanosheets were immobilized on the porous biochar derived from fungus residue, forming a novel biochar-based nanocomposite (MoS2–PDA@FRC) for the removal of Rhodamine B(RhB) and Pb(II) from water. Utilizing MoS2 nanosheets with abundant active adsorption sites, MoS2–PDA@FRC showed higher adsorption capacities than raw biochar, with 2.76 and 1.78 times higher capacities for RhB and Pb(II) respectively. MoS2–PDA@FRC also exhibited fast adsorption kinetics for RhB (120 min) and Pb (180 min) removal, as well as satisfactory adsorption selectivity in the presence of coexisting substances. The underlying removal mechanism was explored via Fourier transform infrared and X-ray photoelectron spectroscopies. Furthermore, during cyclic adsorption–regeneration and the fixed-bed adsorption experiments, the nanocomposite removed RhB and Pb(II) with high effectiveness and stability. Collectively, the results demonstrated the bright prospects of MoS2–PDA@FRC as a highly efficient decontamination agent of RhB and Pb(II) from water.