Removal Of Malachite Green Dye Research Articles

Study on Preparation of Calcium-Based Modified Coal Gangue and Its Adsorption Dye Characteristics.

Efficient and thorough treatment of dye wastewater is essential to achieve ecological harmony. In this study, a new type of calcium-based modified coal gangue (Ca-CG) was prepared by using solid waste coal gangue as raw material and a CaCl2 modifier, which was used for the removal of malachite green, methylene blue, crystal violet, methyl violet and other dyes in water. When the dosage of Ca-CG was 1-5 g/L, the dosage of Ca-CG was the main factor affecting the dye adsorption effect. The adsorption effects of Ca-CG on four dyes were as follows: malachite green > crystal violet > methylene blue > methyl violet. Kinetics, isotherms and thermodynamic analysis showed that the adsorption of malachite green, methyl blue, crystal violet and methyl violet by Ca-CG fitted the second-order kinetic model, and adsorption with chemical reaction is the main process. The adsorption of four dyes by Ca-CG conformed to the Freundlich model, which is dominated by multi-molecular layer adsorption, and the adsorption was easy to carry out. The adsorption process of Ca-CG on the four dyes was spontaneous. The results of FTIR, XRD and SEM showed that the calcium-based materials such as lipscombite and dolomite were the key to the adsorption of malachite green by Ca-CG, and the main mechanisms for the adsorption of malachite green by Ca-CG are surface precipitation, electrostatic action, and chelation reaction. Ca-CG adsorption has great potential for the removal of dye wastewater.

Preparation of novel green adsorbent (Tabernaemontana divaricata leaf powder) and evaluation of its dye (malachite green) removal capacity, mechanism, kinetics, and phytotoxicity

In this study, a novel green adsorbent, Tabernaemontana divaricata leaf powder (TD), was prepared, and its efficacy in removing malachite green (MG) dye from water, along with the associated mechanism and kinetics, was systematically evaluated for the first time. Characterization of TD was carried out using scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). Optimization of MG dye removal was conducted by varying parameters such as pH, initial dye concentration, contact time, and TD dosage. Results demonstrated that TD exhibited a high adsorption capacity for MG dye (5.2131 mg.g−1), achieving a maximum removal efficiency of 89.5 % under optimized conditions: pH 7.0, initial dye concentration of 20 ppm, contact time of 120 min, TD dosage of 4 g/L, and temperature of 28.1 °C. Kinetic and isotherm models were applied to analyze the experimental data, revealing that the adsorption process most accurately followed Ho's pseudo-second-order kinetic model (R2 = 0.999). The high heats of adsorption observed in the isotherm study suggest prominent electrostatic interactions between adsorbate molecules and the surface, governing the chemisorption mechanism that dominates at the solid-liquid interface. This study underscores the potential of Tabernaemontana divaricata (jasmine) leaf powder as a cost-effective, environmentally friendly, and efficient adsorbent for the remediation of MG dye-contaminated water.

Novel hydrogel based on natural hybrid backbones: optimized synthesis and effective adsorbent for the removal of malachite green dye from an aqueous solution

Novel hydrogel based on natural hybrid backbones: optimized synthesis and effective adsorbent for the removal of malachite green dye from an aqueous solution

Optimization of Hazardous Malachite Green Dye Removal Process Using Double Derivatized Guar Gum Polymer: A Fractional Factorial L9 Approach

The dye molecules are one of the water-polluting agents among other contaminants in water bodies and impart unsuitability. In recent years, bio-based materials have attracted considerable attention for varied industrial applications due to their abundant availability on a sustainable basis, biodegradability, cost and energy efficiency. The present study hypothesized to synthesize carboxymethyl-hydroxypropyl guar gum (CMHPGG) dual derivative to remove malachite green dye from an aqueous medium using Taguchi's L9 design. The 73 % dye adsorption was achieved using CMHPGG, comprising carboxymethyl (DS 0.58) and hydroxypropyl (0.128 %) groups. The temperature, pH of the medium and amount of CMHPGG were selected as dye adsorption process control factors. The optimized reaction conditions comprise pH 5, CMHPGG-2, 250 mg/100 mL, and a temperature of 45°C. The characteristic asymmetric (1643 cm−1) and symmetric (1590 cm−1) absorption bands (-COO¯) were observed in the CMHPGG. The roughness was observed on the surface that was increased on derivatization. The thermal behaviour revealed better thermal stability compared to native GG.

Microalgae derived honeycomb structured mesoporous diatom biosilica for adsorption of malachite green: Process optimization and modeling

The present study investigated the removal of malachite green dye from aquifers by means of microalgae-derived mesoporous diatom biosilica. The various process variables (dye concentration, pH, and adsorbent dose) influencing the removal of the dye were optimized and their interactive effects on the removal efficiency were explored by response surface methodology. The pH of the solution (pH = 5.26) was found to be the most dominating among other tested variables. The Langmuir isotherm (R2 = 0.995) best fitted the equilibrium adsorption data with an adsorption capacity of 40.7 mg/g at 323 K and pseudo-second-order model (R2 = 0.983) best elucidated the rate of dye removal (10.6 mg/g). The underlying mechanism of adsorption was investigated by Weber-Morris and Boyd models and results revealed that the film diffusion governed the overall adsorption process. The theoretical investigations on the dye structure using DFT-based chemical reactivity descriptors indicated that malachite green cations are electrophilic, reactive and possess the ability to accept electrons, and are strongly adsorbed on the surface of diatom biosilica. Also, the Fukui function analysis proposed the favorable adsorption sites available on the adsorbent surface.

Super capacity of ligand-engineered biochar for sorption of malachite green dye: key role of functional moieties and mesoporous structure.

This study synthesized a new thiomalic acid-modified rice husk biochar (TMA-BC) as a versatile and eco-friendly sorbent. After undergoing chemical treatments, the mercerized rice husk biochar (NaOH-BC) and TMA-BC samples showed higher BET surface area values of 277.1 m2/g and 305.8 m2/g, respectively, compared to the pristine biochar (BC) sample, which had a surface area of 234.2 m2/g. In batch adsorption experiments, it was found that the highest removal efficiency for malachite green (MG) was achieved with TMA-BC, reaching 96.4%, while NaOH-BC and BC exhibited removal efficiencies of 38.6% and 27.9%, respectively, at pH 8. The engineered TMA-BC exhibited a super adsorption capacity of 104.17mg/g for MG dye at pH 8.0 and 25°C with a dosage of 2g/L. The SEM, TEM, XPS, and FTIR spectroscopy analyses were performed to examine mesoporous features and successful TMA-BC carboxylic and thiol functional groups grafting on biochar. Electrostatic forces, such as π - π interactions, hydrogen bonding, and pore intrusion, were identified as key factors in the sorption of MG dye. As compared to single-solution adsorption experiments, the binary solution experiments performed at optimized dosages of undesired ions, such as humic acid, sodium dodecyl sulfate surfactant, NaCl, and NaSCN, reflected an increase in MG dye removal of 2.8%, 8.7%, 5.4%, and 12.7%, respectively, which was attributed to unique mesoporous features and grafted functional groups of TMA-BC. Furthermore, the TMA-BC showed promising reusability up to three cycles. Our study indicates that mediocre biochar modified with TMA can provide an eco-friendly and cost-effective alternative to commercially accessible adsorbents.

Highly efficient degradation of basic dyes using gold-coated nature-based supermagnetic iron oxide nanoparticles as eco-friendly nanocatalysts

Nowadays, organic dyes are prevalent components in wastewater discharges due to their extensive use in various industries, posing a significant threat to public health across different organisms. As a result, wastewater treatment has become an indispensable requirement. In this study, we synthesized supermagnetic iron oxide (Fe3O4 NPs) and gold-iron oxide bimetallic nanoparticles (Au@Fe3O4 BNPs) using an eco-friendly method that involved natural compounds extracted from brown Egyptian propolis. We employed UV-visible spectroscopy, FTIR, XRD, VSM, SEM, HRTEM, EDX, Zeta potential and XPS techniques to examine the optical characteristics, chemical structure, crystalline structure, magnetic properties, morphology, size, and chemical composition of these biosynthesized nanoparticles. Furthermore, these nanoparticles were used as nanocatalysts for the removal of cationic dyes. The photocatalytic results indicated high efficiency in the removal of methylene blue (MB), crystal violet (CV), and malachite green (MG) dyes from aqueous solutions using Fe3O4 NPs and Au@Fe3O4 BNPs. The removal rates of MB, CV, and MG were about 95.2% in 70 min, 99.4% in 50 min, and 96.2% in 60 min for Fe3O4 NPs, and 97.1% in 50 min, 99.1% in 30 min, and 98.1% in 50 min for Au@Fe3O4 BNPs, respectively. The study also assessed the potential anti-radical properties of the extract, Fe3O4 NPs, and Au@Fe3O4 BNPs using the DPPH assay, and the results demonstrated their antioxidant activity. Finally, these Fe3O4 NPs and Au@Fe3O4 BNPs have the potential to serve as efficient antioxidants and photocatalysts for removing basic dyes from water.Graphical abstract

CaO@ZrO2@g-C3N4 nanosorbent for superior malachite green dye selectivity and adsorption from contaminated water

The steady rise in the volume of waste produced by the forestry, lumber, and paper sectors has necessitated the exploration of methods to convert these waste products into commercially advantageous resources for human use. The present study presents the synthesis and utilization of CaO@ZrO2@g-C3N4 (CZCN) as an innovative adsorbent for eliminating malachite green (MG) from aqueous solutions. The CZCN nanosorbent was subjected to characterization using various analytical techniques, including XRD, EDX, TEM, BET, FTIR, and XPS. The examination of characterizations indicated that the CZCN exhibited a limited range of particle sizes and possessed a significant surface area. The findings from the adsorption experiments demonstrated a correlation between the efficiency of MG dye removal and variations in solution pH, starting concentration, and reaction time. The adsorption equilibrium isotherm demonstrated that the adsorption of MG adhered to the Langmuir isotherm model, exhibiting a maximum adsorption capacity of 1140 mg/g. A pseudo-second-order kinetic model best described the experimental data. The CZCN nanosorbent exhibits promising adsorption capabilities, suggesting potential for future investigation and utilization in treating wastewater containing dyes.

Investigations on Chemically Synthesized Pure and Doped Manganese Dioxide Nanoparticles for Dye Removal and Photocatalytic Applications.

Pure and Mg2+, Ni2+, Cd2+ doped MnO2 nanoparticles were synthesized by chemical co-precipitation method. These samples were characterised by PXRD, SEM, EDX, FTIR, UV-Vis-NIR, PL, Antibacterial, Cyclic Voltammetry, Dye Degradation and Photocatalytic studies. From the powder XRD studies, the crystallite size of the particle was calculated using Scherer formula and found that the synthesized nanoparticles were in the range from 10 to 12nm. The morphology of all the synthesized samples was viewed from SEM micrograph. The composition and purity of the samples were identified from EDX studies. In FTIR spectra metal-oxygen stretching and bending modes of vibrations were observed. From the absorption spectra of UV-Vis optical analysis values of absorption coefficient, extinction coefficient, refractive index, real and imaginary part of optical dielectric constant and optical conductivity were compared. The band gap energy obtained from Tauc's plot varies from 1.21 to 1.51eV exhibits semiconducting behaviour of all the synthesized samples. Investigations on photoluminecsence spectrum reveals blue shift in wavelength for doped nanooxides compared to pure MnO2. Antimicrobial activity of synthesised samples against gram positive and gram negative bacteria was determined. The obtained results reveal very high bacterial resistance in Cd2+ doped MnO2 nanoparticles with higher activity towards bacterial resistance compared to standard drug. The specific capacitance values were determined from Cyclic Voltammetry studies. Using the batch method of dye removing technique the percentage of malachite green dye removal was calculated. Also the photocatalytic efficiency of all the synthesized MnO2 samples in removing malachite green dye was studied by exposing to sunlight for different dosage and contact time. Ni2+ doped MnO2 shows relatively higher % of dye degradation capacity about 93% for 0.1g of dosage of photocatalysts.

Novel high-efficient adsorbent based on modified gelatin/montmorillonite nanocomposite for removal of malachite green dye

Shortage of drinking water has gained potential interest over the last few decades. Discharged industrial effluent, including various toxic pollutants, to water surfaces is one of the most serious environmental issues. The adsorption technique has become a widely studied method for the removal of toxic pollutants, specifically synthetic dyes, from wastewater due to its cost-effectiveness, high selectivity, and ease of operation. In this study, a novel gelatin-crosslinked-poly(acrylamide-co-itaconic acid)/montmorillonite (MMT) nanoclay nanocomposites-based adsorbent has been prepared for removing malachite green (MG) dye from an aqueous solution. Modified gelatin nanocomposites were synthesized using a free-radical polymerization technique in the presence and absence of MMT. Various analytical instrumentation: including FTIR, FESEM, XRD, and TEM techniques were used to elucidate the chemical structure and surface morphology of the prepared samples. Using a batch adsorption experiment, Langmuir isotherm model showed that the prepared modified gelatin nanocomposite had a maximum adsorption capacity of 950.5 mg/g using 350 mg/L of MG dye at pH 9 within 45 min. Furthermore, the regeneration study showed good recyclability for the obtained nanocomposite through four consecutive reusable cycles. Therefore, the fabricated gelatin nanocomposite is an attractive adsorbent for MG dye elimination from aqueous solutions.

Synthesis of trimethoprim vanillin anchored conjugate imprinted polymers for removal of bromocresol green and malachite green from aqueous media

Bromocresol green (BCG) and malachite green (MG) are water-soluble toxic organic dyes with adverse health and environmental implications. This study presented a conjugate imprinted adsorbent (CIA) synthesized by incorporating trimethoprim vanillin ligand into a highly crosslinked polymer, designed for the efficient removal of BCG and MG from wastewater. Characterization of CIA involved X-ray powder diffraction, Fourier transform infrared, and scanning electron microscopic analyses. Batch adsorption processes were conducted to evaluate the adsorption characteristics of CIA, with focuses on the effects of contact time, initial dye concentration, pH, and temperature. The molecularly imprinted polymers (MIPs) achieved removal efficiencies of 99.27% and 98.99% at equilibrium for BCG and MG adsorption, respectively. The non-imprinted polymers (NIPs) demonstrated BCG and MG adsorption efficiencies of 51.52% and 62.90% at equilibrium, respectively. Kinetic and isotherm models were employed to elucidate the BCG and MG adsorption mechanisms. The thermodynamic results indicated non-spontaneous and spontaneous reactions for BCG and MG adsorption on MIPs under the examined temperature conditions. The adsorbent exhibited sustained high removal efficiency through five reuse cycles, with no apparent reduction in adsorption performance. Validation of the adsorbent using real textile wastewater samples achieved BCG and MG removal efficiencies of 85.5%–87.5%. The adsorbent outperformed previously reported materials in BCG and MG adsorption. The synthesized CIA is a promising adsorbent for BCG and MG dye removal, contributing to water sustainability.

Bio-adsorption of Cationic-Cnionic Dyes from Synthetic Effluents using an Experimental Design Approach

In the current research, Cycas leaves powder (CL) as a low-cost agro-waste adsorbent was investigated for malachite green (MG) and Indigo Carmine (IC) dye removal from contaminated water. The Cycas leaves powder was characterized by Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared (FTIR) techniques. The adsorption parameters were investigated including contact time, dye concentrations, and adsorbent dosage to determine their effects on the adsorption efficiency. The I-optimal design approach was used to intimately detect the significance of adsorption parameters and their interactions by analyzing the overall statistical results. The adsorption isotherm and kinetics were analyzed using two models. The results showed that the data was well-fitted with the Freundlich isotherm model and the adsorption kinetics followed the pseudo-first-order model. The thermodynamics parameters including ΔHº, ΔSº, and ΔGº were determined, and the adsorption process was non-spontaneous, and exothermic for MG and endothermic IC dyes. The results demonstrated that Cycas leave can be exploited as an affordable inexpensive material for the treatment of industrial dyes from textile discharges.

Malachite green and methylene blue dye removal using modified bagasse fly ash: Adsorption optimization studies

Utilizing Bagasse Fly Ash (BFA) as an adsorbent, a byproduct from the sugar industry, proved effective in removing a mixture of Malachite Green and Methylene Blue dyes from aqueous solutions. To enhance its efficacy, the fly ash underwent chemical modification and underwent detailed characterization using FTIR, XRD, SEM, and TGA analyses. Subsequently, adsorption studies were conducted to optimize critical parameters—initial dye concentration, contact time, and pH levels—employing a Mixed-Level Factorial design to pinpoint the most favorable conditions for efficient dye removal. The modified Bagasse Fly Ash (BFA) resulted in a maximum adsorption capacity of 18.75 mg/g (71.5 %) for Malachite Green and 15.5 mg/g (67.2 %) for Methylene Blue at initial dye concentration of 100 mg/L, pH of 9.6, and time of 51.5 min. Analysis of the sorption data involved rigorous application of both Langmuir and Freundlich isotherm models, revealing a strong fit of the linear representation to the data for both dyes. Specifically, R2 values of 0.97 and 0.93 were observed for Malachite Green, while notably higher values of 0.99 and 0.96 were obtained for Methylene Blue, affirming an excellent model-data agreement. Additionally, a kinetic study revealed that the dye adsorption process (MB and MG) followed the pseudo-second-order kinetic model (R2 > 0.99), indicating that chemisorption as dominant adsorption mechanism and providing valuable insights into the dynamic behavior of the process.

Preperation of sodium alginate-based SA-g-poly(ITA-co-VBS)/RC hydrogel nanocomposites: And their application towards dye adsorption

A superabsorbent polymer, Sodium Alginate-g-Poly (Itaconic acid-co-Sodium 4-vinyl benzenesulfonate)/ Ricinus communis (SA-g-P(ITA-co-VBS)/ RC) hydrogel, was prepared by free-radical graft co-polymerization for sequestration of toxic malachite green (MG) dye as a cationic dye model. The surface morphological of shape and composition of the prepared hydrogel used have been characterized by FESEM, EDX, TEM, FTIR, X-ray diffraction XRD, and TGA. Optimizing the synthesis conditions for prepared a hydrogel with the highest swelling ratio have been studied, the results show that employing 0.08 g KPS and 0.09 g MBA, 1.0 g ITA, 2.0 g VBS, 1.0 g SA, and 1.0 g RC, the composites greatest swelling capacity in distilled water was 3400 %. It was discovered that the dye adsorption capacity of the polymer was greatly impacted by the monomer VBS level in the hydrogel, which gives it a better ability to swell. The porosity of the hydrogel spheres, thus significantly enhancing the MG adsorption capacity with the rate-limiting controlled by chemical adsorption, intraparticle diffusion, and film diffusion. Study the influence of different reaction conditions on the removal of MG dye from aqueous solution are adsorbent dose, pH, zero-point charge, temperature, thermodynamic adsorption, adsorption isotherm, and kinetic models have been done. Additionally, (SA-g-P(ITA-co-VBS)/RC) demonstrated strong MG dye adsorption capabilities and reusability in at least four adsorption-desorption cycles this process indicating its considerable potential for use as the adsorbent for dye removals from aqueous solution.

Comprehensive Evaluation of Polyaniline-Doped Lignosulfonate in Adsorbing Dye and Heavy Metal Ions.

Lignosulfonate/polyaniline (LS/PANI) nanocomposite adsorbent materials were prepared by the chemical polymerization of lignosulfonate with an aniline monomer as a dopant and structure-directing agent, and the adsorption behavior of dyes as well as heavy metal ions was investigated. LS/PANI composites were used as dye adsorbents for the removal of different cationic dyes (malachite green, methylene blue, and crystal violet). The adsorption behavior of LS/PANI composites as dye adsorbents for malachite green was investigated by examining the effects of the adsorbent dosage, solution pH, initial concentration of dye, adsorption time, and temperature on the adsorption properties of this dye. The following conclusions were obtained. The optimum adsorption conditions for the removal of malachite green dye when LS/PANI composites were used as malachite green dye adsorbents were as follows: an adsorbent dosage of 20 mg, an initial concentration of the dye of 250 mg/L, an adsorption time of 300 min, and a temperature of 358 K. The LS/PANI composite adsorbed malachite green dye in accordance with the Langmuir adsorption model and pseudo-second-order kinetic model, which belongs to chemisorption-based monomolecular adsorption, and the equilibrium adsorption amount was 245.75 mg/g. In particular, the adsorption of heavy metal ion Pb2+ was investigated, and the removal performance was also favorable for Pb2+.

Cerium-Doped Calcium Ferrite for Malachite Green Dye Removal and Antibacterial Activities

Cerium-Doped Calcium Ferrite for Malachite Green Dye Removal and Antibacterial Activities

Synthesizing pectin-crosslinked gum ghatti hydrogel for efficient adsorptive removal of malachite green

Pectin-crosslinked gum ghatti hydrogel (PGH) has been synthesized utilizing pectin and gum ghatti through an uncomplicated and inexpensive copolymerization method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM-elemental mapping), Brunauer-Emmett-Teller (BET), and X-ray photoelectron spectroscopy (XPS) characterization techniques have been employed to determine various structural, chemical and compositional characteristics of fabricated PGH. Three different weight ratios (1:1, 2:1, or 1:2 for pectin and gum ghatti, respectively) were employed to synthesize three distinct types of PGH. Swelling studies has been done to determine the best ratios for PGH fabrication. PGH has been assessed as an adsorbent for the removal of malachite green dye from aqueous solutions. The effects of PGH dosage (100–400 mg/L), dye concentration (10–160 mg/L), pH (2–9 pH), adsorption time (0–480 min), and temperature (25–55 °C) has been examined through batch solutions. According to Langmuir isotherm analysis, the maximum adsorption capacity is 658.1 mg/g. By using pseudo-second-order kinetics and the Freundlich adsorption isotherm, the adsorption process could be well explained. After five consecutive cycles, PGH had an adsorption percentage of 86.917 % for the malachite green dye. It is safe for the environment and may be used to remove malachite green (MG) dye from aqueous solutions.

Removal of Malachite Green by Poly(acrylamide-co-acrylic acid) Hydrogels: Analysis of Coulombic and Hydrogen Bond Donor-Acceptor Interactions.

Water pollution caused by dyes poses a significant threat to life on earth. Poly(acrylamide-co-acrylic acid) hydrogels are widely used to treat wastewater from various pollutants. This study aims to examine the removal of malachite green (MG), a harmful and persistent dye that could cause extensive environmental damage, from an aqueous solution by adjusting the initial concentration of acrylamide (AM) and the degree of copolymer crosslinking. The copolymer hydrogels efficiently eliminate MG in a brief timeframe. The most successful hydrogel accomplished a removal rate exceeding 96%. The copolymer of 4 wt % 1,6-hexanediol diacrylate and a concentration of 100 mg/mL AM was effective. The degree of swelling was affected by crosslinking density as expected, with low crosslinking ratios resulting in significant swelling and high ratios resulting in less swelling. To evaluate the results, a docking approach was used which presented three crosslinked models: low, medium, and high. The copolymer-dye hydrogel system displayed robust hydrogen bonding interactions, as confirmed by the high quantities of both donors and acceptors. It was determined that MG contains six rotatable bonds, enabling it to adapt and interact with the copolymer chains. The dye and copolymer enhance H-bond formation by providing two hydrogen bond donors and 16 hydrogen bond acceptors, respectively. Through capitalizing on cationic and anionic effects, the ionic MG/copolymer hydrogel system improves retention efficiency by enhancing attraction between opposing charges. It is interesting to note that the synthesized copolymer is able to remove 96.4% of MG from aqueous media within one hour of contact time.

Comparison of effective removal of cationic malachite green dye from waste water with three different adsorbents: date palm, date palm biochar and phosphated biochar

ABSTRACT Adsorbents obtained from agricultural wastes attract attention because they are both effective, inexpensive and environmentally friendly. In this study, it was studied on the removal of malachite green (MG) from aqueous solutions by using date palm fronds (DPF), which are agricultural wastes, date biochar (DPC) obtained by pyrolysis and phosphated date biochar with the help of microwave pyrolysis (DPMW) as three different adsorbents. Characterisation of adsorbents was made by FTIR/ATR, SEM, TGA. According to the results of TGA, it was observed that thermal strengths decreased after adsorption. Adsorption studies were carried out at 25°C in isothermal environment at the pH of the natural dye solution. Adsorption data of date palm, biochar and phosphated biochar were evaluated according to Freundlich, Langmuir, Temkin, Dubinin-Radushkevich (D-R), Flory-Huggings (F-H) and Fowler-Frumkin-Guggenheim (FFG) isotherm models. Maximum adsorption capacities (qmax) according to Langmuir isotherm were found as 334 mg/g, 125 mg/g and 32 mg/g for date palm, biochar and phosphated biochar, respectively. The heat of adsorption calculated using the Temkin and Fowler – Frumkin-Guggenheim (FFG) isotherms is exothermic for date palm and biochar, while it is endothermic for phosphated biochar. It was observed that the adsorption mechanism energy E calculated in D-R and the B values calculated in Temkin were compatible and the adsorption was physical. According to these results, the most effective adsorbent for the removal of malachite green from aqueous solutions is biochar, which is the pyrolysis product, while phosphated biochar is not very suitable.

Photocatalytic degradation of malachite green by waste derived bio-char impregnated Bi5O7Br/Fe3O4 magnetic composite

We report the fabrication of a novel waste-derived biochar-impregnated Bi5O7Br/Fe3O4 (WBF) magnetic composite for photocatalytic removal of malachite green pollutant. The newly prepared catalyst was applied for the removal of malachite green dye under visible light irradiation. It was found that the composite degrades 99.39% MG dye within 20 min of the experiment as compared to Bi5O7Br, Fe3O4, and biochar with 83.19%, 75.09%, and 55.47% in the 50-min experiment. The findings demonstrated that a photocatalytic integrated composite quickly transfers charges across surfaces and effectively separates electron-hole pairs, considerably increasing charge carrier separation and photocatalytic activity. Further, the kinetics show that the rate constant for WBF composite is 7.1 times higher than that observed for Bi5O7Br. Scavenging experiments reveal the huge role of.OH and •O2− radicals in malachite green degradation. Additionally, the magnetic nature of the catalyst ensures the easy separation of the catalyst during photocatlytic experiments and reduces the chance of secondary pollution. The results showed that integrating Bi5O7Br and biochar with Fe3O4 to create photocatalytic composites is a very efficient strategy to boost photocatalytic activity for environmental waste water treatment.