Initial Malachite Green Concentration Research Articles

Chitosan cross-linked polyaniline grafted graphene oxide composite: a new adsorbent to remove phenol and cationic dye from aqueous solutions

ABSTRACT Rapid industrialisation has led to severe environmental pollution, mainly due to the discharge of organic pollutants into the waterbodies. The removal of organic compounds such as dyes and phenolic pollutants from the industrial effluents before it is discharged should be the top priority. This article synthesised a novel chitosan cross-linked polyaniline grafted graphene oxide (CS-PANI@GO) composite with variable morphology, enhanced surface area, low cost, biocompatibility, and notable characteristics of high malachite green (MG) and phenol adsorption capacity. The physicochemical properties of CS-PANI@GO were studied by FESEM, FTIR, XRD, RAMAN, BET, and BJH pore size distribution. FESEM analysis demonstrated that the surface of CS-PANI@GO composite is porous in nature. The BET surface area of the composite is 88.91 m2/g. The effect of various parameters such as temperature, pH of the solution, initial concentration of MG and phenol, adsorption time, and dosage were investigated, and the optimal values were recorded. The adsorption performance of CS-PANI@GO composite for both MG and phenol follows the pseudo-second-order model suggests chemisorption occurs in the process. For MG dye, the adsorption equilibrium data follows the Freundlich model and for phenol, the data follows the Langmuir model. The maximum uptake for MG dye and phenol were 699.022 mg/g and 198.254 mg/g, respectively. Thermodynamic data demonstrated that the process of MG and phenol adsorption was spontaneous, endothermic, and feasible. The recyclability study shows that after five cycles of regeneration, the composite has excellent adsorption performance. The adsorption mechanism is also proposed to be hydrogen bond, π-π interaction, and electrostatic attraction. Based on the present adsorption results under various parameter conditions, the synthesised novel CS-PANI@GO composite could be applied as an efficient adsorbent for the treatment of dyes and phenolic pollutants from wastewater.

Enhanced adsorption of malachite green on hydroxyl functionalized coal: Behaviors and mechanisms

The discharge of untreated colored wastewater poses a severe threat to global health. This work reports a simple yet highly efficient way to modify Zhundong coal (MZD) with hydroxyl functional groups for malachite green (MG) removal. The modification significantly improved the adsorption capacity of MG from 63.0 mg/g to 538.7 mg/g. According to Fourier transform infrared spectroscopy, zeta-potential analyzer, X-ray photoelectron spectroscopy, and N2 absorption characterization, the improvement in adsorption capacity was mainly attributed to the enhancement of hydroxyl functional groups on the surface of coal. The adsorption of MG on MZD depended on pH, and the highest removal efficiency reached 99.7% at pH 10 with an initial MG concentration of 500 mg/L. The adsorption process was mainly controlled by chemisorption, and it was endothermic and spontaneous according to thermodynamic analysis. The adsorption data could be well reproduced by the pseudo-second order kinetic model and the Redlich-Peterson isotherm model. The MZD shows good regeneration performance with only a 16.9% reduction of initial adsorption capacity after five circles. Hydrophobic interactions, π-π interactions, and pore-filling contributed to adsorption, whereas electrostatic interactions played a dominant role in the MG removal by MZD. This work provides a new sight to prepare useful and cheap adsorbents from coal to remove contaminants from printing and dyeing wastewater.

Experimental and computational studies of microwave-assisted watermelon rind – styrene based molecular imprinted polymer for the removal of malachite green from aqueous solution

A microwave-assisted watermelon rind imprinted biosorbent polymer (MAWIMOS) was successfully synthesized and applied as an effective removal of malachite green (MG) dye from wastewater. The successful incorporation of imprinted cavities into the MAWIMOS was confirmed by scanning electron microscopy (SEM), X-ray diffractometry (XRD), and Fourier transform infrared spectroscopy (FTIR). A sequence of adsorption studies was carried out to evaluate the influence of operational parameters such as contact time, initial analyte concentration and temperature on MG removal by the prepared polymer. Equilibrium dye removal was attained within 60 min, giving a % removal of 95.2% at initial MG concentration of 200 mg/L. This value was much higher than 59.3% recorded with non-imprinted polymer (NIP). Thermodynamic studies revealed the spontaneous and exothermic nature of the adsorption process. Kinetic and equilibrium data fitted better to the pseudo-second-order and Freundlich models, respectively. Density functional theory (DFT) study suggested the main interaction mechanism to be by chelation through charge flow from the adsorbent to the MG in solution; and that MG and styrene monomer formed ordered complexes via π−π interactions when the molar ratio between MG and styrene was 1:5. The high quantity of malachite green removed by the MAWIMOS strongly positions the material as an efficient adsorbent for wastewater treatment.

Performance evaluation of polymer-marine biomass based bionanocomposite for the adsorptive removal of malachite green from synthetic wastewater.

In this experimental investigation, feasibility and performance of a polymer hybrid bio-nano composite were evaluated to remove malachite green (MG) under controlled environment conditions. The polymer hybrid bio-nanocomposite was characterized using FTIR, SEM and EDS. The influence of operating variables, namely effect of pH (2-11), nanocomposite dosage (20-100mg), initial MG concentration (10- 200mg/L), contact time (10-120min) and temperature (298-318K) were explored. The maximum removal efficiency (RE) of 99.79% was achieved at neutral pH at the dosage level of 50mg with the initial MG concentration of 150mg/L in 40min. The equilibrium results revealed that the adsorption of MG data fitted to Langmuir isotherm (R2>0.970) indicating monolayer adsorption. The maximum adsorption capacity of polymer hybrid nanocomposite was found to be 384.615mg/g. Kinetic studies were performed using five kinetic models and results showed the pseudo second order model fitted very well with the MG adsorption data (R2>0.990). The thermodynamic results confirmed that MG adsorption onto polymer hybrid nanocomposite is feasible and (ΔS ͦ=0.2893kJ/mol K), spontaneous (ΔH ͦ=81.103kJ/mol K) and exothermic (ΔG ͦ<0). A mechanism is also proposed for the removal of MG using the polymer nanocomposite and identified that electrostatic attraction and hydrogen bonding as the major mechanism for removal of MG. FTIR results confirmed the presence of carboxyl (-COO) and hydroxyl (-OH) groups which helped in effective binding of cationic dye. The overall results revealed that polymer nanocomposite could be used as a potential adsorbent for removing MG from aqueous solution.

Photoactive of Chitosan-ZrO2/TiO2 thin film in catalytic degradation of malachite green dyes by solar light

The large band gap energy of titanium dioxide (TiO2) nanoparticle catalysts hinders them from functioning effectively under solar radiation, encouraging detrimental charge carrier recombination and inadequate adsorption characteristics. Hence, to solve these issues, Chitosan (CS) and Zirconia (ZrO2) were integrated into TiO2 nanoparticles through a sol-gel fabrication method to generate the thin film CS-ZrO2/TiO2 catalyst. CS-ZrO2/TiO2 was found to be in a homogenous spherical form, with particle sizes ranging from 40 to 90 nm, according to micrograph images. Infrared spectroscopy revealed that the Ti–O–Ti, Ti–O-to-NH2, and Ti–O-to-OH groups formed coordinate covalent bonds in the hybrid catalysts. The prominent diffraction peaks identified in XRD spectra confirmed ZrO2. The band gap energies of CS-ZrO2/TiO2 hybrids with diverse Ti/Zr weight ratios were successfully reduced to a value lower than pure TiO2. The photocatalytic activity of CS-ZrO2/TiO2 hybrid with 10% of ZrO2 was proved to be the most efficient photocatalyst with the highest rate constant 9.673 × 10−3 min−1 than pure TiO2 at 2.994 × 10−3 min−1. Photodegradation efficiency of model dyes compounds, malachite green (MG) increased from 11.87% to 30.72% with ZrO2 and CS addition in TiO2 catalyst under solar irradiation. The optimum photodegradation condition lowered the initial MG concentration (5 mg/L) in the acidic medium. From the kinetic study, the improvement of photodegradation efficiency was brought by incorporating ZrO2 into pure TiO2 photocatalyst due to the synergistic energy of both components.

Fabrication of magnetically recyclable nanocomposite as an effective adsorbent for the removal of malachite green from water

Herein, a novel magnetic nanocomposite (Fe3O4@ATPA@AMPA) was successfully synthesized for the removal of malachite green (MG) from water. The FT-IR analysis confirmed successful modification of Fe3O4@ATPA with 2-Amino-3-mercaptopropionic acid (APMA). Based on TEM image and XRD pattern, the average particle size of Fe3O4@ATPA@AMPA nanocomposite was ∼ 12.3 nm. The specific surface area of Fe3O4@ATPA@AMPA nanocomposite was 35 m2/g. Elemental analysis exhibited the existence of S, O, C, and N on the surface of Fe3O4 nanoparticles. The influence of time (t: 5–240 min), dose (m: 0.010–0.050 g), pH (2–8.5), initial MG concentration (Co: 25–300 mg/L), and temperature (T: 298–318 K) on the MG adsorption was examined. Experimental results exhibit optimal MG uptake at pH: 6.7, t: 120 min, m: 20 mg, T: 298 K, and Co: 300 mg/L. The non-linear kinetics and isotherm models showed that the adsorption process obeyed pseudo-first-order kinetic and Langmuir isotherm models, respectively. According to Dubinin–Radushkevich (D–R) isotherm, the magnitude of activation energy (Ea) at varied temperatures was in range 0.0116−0.0905 kJ/mol, confirming physical interactions between MG molecules and Fe3O4@ATPA@AMPA nanocomposite dominates during adsorption. The maximum monolayer adsorption capacity for MG was 414.63 mg/g at 298 K. The adsorption process was exothermic, favorable, and spontaneous. Finally, the Fe3O4@ATPA@AMPA nanocomposite exhibited excellent adsorption potential for four consecutive regeneration cycles.

Volcanic ashe and its NaOH modified adsorbent for superb cationic dye uptake from water: Statistical evaluation, optimization, and mechanistic studies

The adsorptive performance of the natural Saudi Arabian volcanic ash (VA) and its NaOH-modified form (VA-NaOH) for Malachite green (MG) uptake from water were evaluated using response surface methodology (RSM) modeling technique and mechanistic aspects studies. The characterization analyses showed that both materials possess abundant functional groups (O–H, Si–OH, Si-O and Al-O), mineral salts (SiO2, Al2O3, CaO, Fe2O3, MgO), better surface characteristics leading to favorable adsorption of MG dye from water. The MG removals and the uptake capacities data were well described by cubic polynomial models with optimal condition at 25 °C, initial MG concentration of 120 mg/L, and pH 10 for VA and VA-NaOH. The kinetics of MG adsorption was best explained by pseudo-second order, while the Redlich–Peterson model fitted the equilibrium isotherms. The maximum Langmuir uptake capacity of 152 mg/g (VA) and 158 mg/g (VA-NaOH). The adsorption mechanism was speculated to be endothermic and involving both mono and multi-layer surface adsorption comprising chemisorption process (ΔG° = −27.6 to −33.9 kJ/mol), with increasing randomness scale at the liquid/solid interface without considerable entropy changes. The excellent regeneration ability, after successive cycles of desorption-adsorption, further indicates the high potential of the natural Saudi volcanic ash as excellent adsorbent for dyes removal from aqueous systems.

Biosorption of Malachite Green by Dry Cells of Isolated Free Living Nitrogen Fixing Bacteria

Contamination of water with Malachite green (MG) may threaten aquatic and human life. Nitrogen-fixing Azotobacter sp. is an efficient adsorbent for the removal of MG from dye solutions. The optimum pH for the biosorption process was determined. The maximum adsorption capacity and the effect of different adsorbate concentrations were detected. The kinetics and isotherm models for biosorption were constructed. Optimum adsorption of MG by Azotobacter sp. was obtained at pH 6.0, biomass concentration was 0.05%, initial dye concentration was 50 mg.L-1, and contact time was 600 mins. Dye adsorption exhibited an increase with contact time and initial malachite green concentration. The kinetics of the adsorption process was best followed by the pseudo-second-order kinetic model which confirms the chemisorption process. The adsorption equilibrium data fit well to the Langmuir model indicating a monolayer adsorption behavior onto a surface of Azotobacter sp. with a finite number of active sites. Maximum biosorption capacity was found to be 142.8 mg.g-1 of bacterial biomass. The dry biomass of Azotobacter sp. has proved to be an efficient biosorbent for the removal of synthetic dyes from actual industrial effluent that is contaminated with up to 400 mg.L-1 dye concentration.

Malachite green adsorption from aqueous solutions onto biochar derived from sheep manure: adsorption kinetics, isotherm, thermodynamic, and mechanism

The adsorption of Malachite Green (MG) from aqueous solution was achieved using biochar derived from sheep manure pyrolyzed at 450 °C. Sheep manure biochar was characterized before and after adsorption of MG by SEM and FTIR. In addition, surface area measurement was performed by BET surface area and pore analyzer. The influence of contact time, pH, dose, temperature, and initial MG concentrations on the adsorption of MG onto sheep manure biochar (SMB) was investigated in experiments. Langmuir, Freundlich, Temkin, and Dubinin-Raduskevich isotherm models were used to analyze the data. Results assumed best fitting model is Langmuir isotherm model (R 2 value 0.99). Mean free adsorption energy (E) was obtained 94.71 kJ mol−1, R L value was between 0.013 and 0.14. That indicates monolayer, favorable, and physisorption adsorption, as well as an endothermic adsorption process. Maximum uptake value from Langmuir model obtained 208.33 mg g−1. Surface area of SM biochar was 11.731 m2 g−1. NOVELTY STATEMENT This study is the first study on the adsorption of malachite green dye substance on sheep manure derived biochar. A natural and cheap adsorbent with high dye removal, such as 208,33 mg g−1. A guiding study for the conversion of agricultural waste into products with highly added value.

Heterogeneous photoelectro-Fenton using ZnO and TiO2 thin film as photocatalyst for photocatalytic degradation Malachite Green

Titanium dioxide (TiO2) and zinc oxide (ZnO) particles as photocatalysts are known to be effective in the degradation of various organic pollutants. Here we use a simple way of preparing an active TiO2 thin film for Malachite Green (MG) elimination from an aqueous solution based on a combination of advanced oxidation processes (electro Fenton and photocatalytic degradation) under UV wavelengths irradiation. The TiO2 and ZnO as nano-photocatalytic material as thin layers on the glass surface are applied. For the characterization of synthesized ZnO and TiO2 paste, SEM, TEM and XRD were used. The effects of operational variables on the degradation of MG were studied by central composite design (CCD). The results showed that MG was degraded by the TiO2 and ZnO pastes in photoelectro-Fenton system under UV irradiation at optimum conditions with 79.4 and 97.5% degradation efficiency, respectively, which reaction constant of thin film ZnO was 1.96 times as high as that of the TiO2 paste in the mentioned system. The optimum degradation conditions for thin film ZnO were as follows: pH of 3, 30 mg/L of initial MG concentration, 200 mA of electrical current, 0.4 mmol/L of FeCl3, and 16 min of contact time. In addition, the degradation rates of MG by both photocatalysts in the photoelectro-Fenton system could be explained in terms of the Langmuir-Hinshelwood pseudo-first-order kinetic equation.

Composites of cellulose nanofibers and silver nanoparticles for malachite green dye removal from water

The development of eco-friendly materials to remove toxic chemicals from water is highly sought after in the present days. In the current study, the composites of cellulose nanofiber (CNF) and silver nanoparticles (Ag NPs) were prepared and their ability to adsorb malachite green (MG) dye under different conditions was investigated. XRD, FTIR, EDX analyses of samples confirmed the presence of Ag NPs on the CNFs and the sorption of MG dye on composites. The effects of various parameters (such as contact time, CNFs - Ag NPs dose, initial MG concentration, pH, and temperature) on MG degradation were evaluated. The maximum removal was obtained at a pH of 8 and temperature of 303 K. The adsorption equilibrium was described well by the Freundlich isotherm model suggesting multilayer physical adsorption. The maximum uptake of MG dye using CNF-Ag NPs composites was found to be 142 mg/g, which is superior to the silver-based composites reported in the literature. Adsorption kinetics were predicted by the pseudo-first-order kinetic model rather than the pseudo-second-order kinetic model. This method is promising due to its cost-effective nature as well as the use of bio-based materials.

Enhancement of Adsorption-Photocatalysis of Malachite Green Using Oil Palm Biomass-Derived Activated Carbon/ Titanium Dioxide Composite

Background: Nowadays, effective wastewater treatment has become a hot research topic in the field of environment. A series of novel activated carbon/ titanium dioxide (AC/TiO2) composites at various weight ratio were synthesised using the sol-gel method and were characterised using XRD, SEM-EDX, FT-IR, TGA and surface area analysis. Method: TiO2 particles were successfully incorporated on the AC surface and were mainly composed of Ti, O and C atoms. The AC/TiO2 composites were made up of spherical TiO2 particles agglomerated on the smooth tubular and porous structure of AC. The photocatalytic efficiency was influenced by the weight proportion of AC:TiO2 and the degradation process was attributed to the adsorption and photocatalytic processes. Results: It was found that 2.5 g/L AC/TiO2 at a weight ratio of 3:1 on an initial Malachite Green concentration of 10 mg/L at 50°C led to a degradation efficiency of 96.3% in 7.5 minutes under a halogen lamp. A chemical oxygen demand (COD) removal of 96.7% was also recorded. Reusability of the AC/TiO2 composite and kinetic study of the photodegradation of Malachite Green were also investigated. The recycled AC/TiO2 composite achieved high catalytic performance (83.1%) after one catalytic cycle. Conclusion: The degradation kinetics of Malachite Green at various solution temperatures were fitted to the pseudo-first-order reactions and the activation energy for the degradation of Malachite Green was 21.48 kJ/mol. This work demonstrated that AC/TiO2 composite is a promising material for photocatalytic degradation of organic dyes.

MgO Functionalized Magnetic Activated Carbon Material for Efficient Removal of Malachite Green from Aqueous Solutions

Malachite green (MG) pollution has a negative impact on human health. At present, the method of removing it is inconvenient to operate and the cost is high, which has aroused widespread concern. In this study, MgO functionalized magnetic activated carbon (MgO-mAC) prepared by the sol–gel method was used to remove MG in water. The physical and chemical properties of MgO-mAC were tested by SEM, TEM, FTIR, XRD, BET and VSM. The effects of adsorbent dosage, solution pH, contact time, initial MG concentration and temperature on adsorption were studied by batch experiments. The adsorption kinetics data is well described by a pseudo-second-order model. The equilibrium data fits the Langmuir isotherm well. When the pH is 8 and the contact time is 360[Formula: see text]min, the maximum adsorption capacity of MG is 3809[Formula: see text]mg[Formula: see text]g[Formula: see text]. In thermodynamic studies, [Formula: see text], [Formula: see text], [Formula: see text], MG adsorption is an endothermic and spontaneous adsorption process. The current synthesis method is simple in operation and cheap in raw materials, which can greatly reduce the cost of synthesis. Hence, the MgO-mAC material will be an effective adsorbent for removing MG from aqueous solutions.

Remediation of malachite green in wastewater by ZIF-8@Fe/Ni nanoparticles based on adsorption and reduction

Dye-contaminated wastewater resulting from rapid industrialization and urbanization is a global problem. In this study, a ZIF-8@Fe/Ni sample was synthesized for the removal of malachite green (MG), removing more than 99% of an initial MG concentration of 50 mg L−1 within 120 min with a 318 K adsorption capacity of 151.520 mg g−1. To understand the dye removal mechanism based on adsorption and reduction, ZIF-8@Fe/Ni was characterized by various techniques. XRD showed that the ZIF-8@Fe/Ni composite had a characteristic peak attributable to Fe/Ni around 44.8°, where the presence of Fe/Ni did not affect the structure of ZIF-8. SEM confirmed that ZIF-8@Fe/Ni was successfully prepared, while XRD and FTIR revealed that the structure of ZIF-8@Fe/Ni remained stable following the introduction of Fe/Ni. XPS showed that while Fe/Ni nanoparticles existed in ZIF-8-Fe/Ni, partial oxidation also occurred. GC–MS demonstrated the creation of two major MG degradation products, (4-aminophenyl) (phenyl) methanone and 4-aminophenol. While the overall adsorption process of MG to ZIF-8@Fe/Ni conformed to pseudo-second-order kinetics, degradation followed pseudo-first-order reduction kinetics. When applied to the remediation of wastewater, ZIF-8@Fe/Ni removed 92% of MG. Overall, this study demonstrated that ZIF-8@Fe/Ni could be a promising material for the treatment of wastewater.

Scavenging malachite green dye from aqueous solution using durian peel based activated carbon

Physiochemical activation consists of heat treatment coupling with CO2 gasification and KOH chemical treatment were applied in preparing durian peel based activated carbon (DPAC) to remove basic dye, malachite green (MG) from aqueous solution. Several parameters namely, effect of initial MG concentration as well as contact time, solution temperature and initial solution pH were carried out in this study. Characterization study revealed that DPAC pose high BET surface area which is 886.31 m2/g and its surface was found to be mesoporous in nature with heterogeneous type of pore structures. Eight isotherms and four kinetic models were utilized and it was revealed that the adsorpttion system followed Freundlich isotherm and pseudo-first order (PFO) kinetic model. Mechanism study using intraparticle diffusion and Boyd plot confirmed that adsorption of MG onto DPAC was controlled by the film-diffusion mechanism. Thermodynamic study indicated that the adsorption system was exothermic, spontaneous, feasible and governed by physical-type of adsorption.

Effective Removal of Malachite Green from Aqueous Solutions Using Magnetic Nanocomposite: Synthesis, Characterization, and Equilibrium Study

In this work, magnetized activated Juniperus procera leaves (Fe3O4@AJPL) were successfully prepared via chemical activation of JPL and in situ coprecipitation with Fe3O4. A Fe3O4@AJPL nanocomposite was successfully applied for the elimination of malachite green (MG) dye from aqueous media. The prepared Fe3O4@AJPL adsorbent was characterized by SEM, EDX, TEM, XRD, FTIR, TGA, and BET surface area analyses. The BET surface area and pore size of the Fe3O4@AJPL nanocomposite were found to be 38.44 m2/g and 10.6 nm, respectively. The XRD and FTIR results indicated the formation of a Fe3O4@AJPL nanocomposite. Different parameters, such as pH of the solution (3–8), adsorbent dosage (10–100 mg), temperature (25–45°C), contact time (5-240 min), and initial MG concentrations (20–350 mg/L), for the elimination of the MG dye using Fe3O4@AJPL were optimized and found to be 7, 50 mg, 45°C, 120 min, and 150 mg/L, respectively. The nonlinear isotherm and kinetic studies exhibited a better fitting to second-order kinetic and Langmuir isotherm models, with a maximum monolayer adsorption capacity of 318.3 mg/g at 45°C, which was highly superior to the previously reported magnetic nanocomposite adsorbents. EDX analyses confirmed the presence of nitrogen on the Fe3O4@AJPL surface after MG adsorption. The calculated thermodynamic factors indicated endothermic and spontaneous processes. The desorption of MG dye from Fe3O4@AJPL was performed using a solution of 90% ethanol. Finally, it could be concluded that the designed Fe3O4@AJPL magnetic nanocomposite will be a cost-effective and promising adsorbent for the elimination of MG from aqueous media.

Malachite Green Removal by Activated Potassium Hydroxide Clove Leaf Agrowaste Biosorbent: Characterization, Kinetic, Isotherm, and Thermodynamic Studies

Although several approaches have been explored for the removal of dyes and other toxic materials from water as well as the entire environment, notwithstanding, researchers/scientists are still pursuing novel, low-cost, and eco-friendly biosorbents for the effective removal of such contaminants. Herein, clove leaves (CL) were utilized as a biosorbent for the sequestration of malachite green (MG) from a water-soluble solution. The CL was subsequently activated using potassium hydroxide (KOH) and characterized using the FTIR and FESEM to determine the functional groups on the activated clove leaves (CL-KOH) and the morphology of the adsorbent. The adsorption of MG was observed to be relatively dependent on the dosage of sorbent utilized, initial MG concentration, and sorption process contact time. The adsorption process of MG to CL was ideally described using the Dubinin–Radushkevich and Elovich models with the determination of maximum sorption capacity of approximately 131.6 mg·g-1. Furthermore, the thermodynamic parameters calculated showed that the adsorption of MG to the adsorbent was exothermic with the process involving physical sorption as well as chemical sorption processes with negligible adsorption energy. In conclusion, the study has revealed that the CL is a cost-effective biosorbent with high adsorption efficiency for the sequestration of MG from a water-soluble solution and can be recycled for further usage.

Facile synthesis of zinc oxide nanoparticles loaded activated carbon as an eco-friendly adsorbent for ultra-removal of malachite green from water

Green synthesis ultrasonic method is reported for the preparation of zinc oxide nanoparticles loaded on activated carbon (AC) derived from coffee waste. The zinc modified AC was used effectively for the elimination of malachite green (MG) from wastewater. The examined batch adsorption parameters are; initial pH (2–9), adsorbent dose (0.10–0.50 g/100 mL), mixing time (5–120 min), MG concentrations (25–300 mg/L) and temperature (298–318 K). XRD, SEM/EDS, FT-IR and TGA/DTA techniques were used to characterize the developed Zn(OH) 2 -AC composite. The results demonstrated that the adsorption capacity of Zn(OH) 2 -AC composite was improved with incremental of the initial dye concentration, pH, and temperature, and decreased as the Zn(OH) 2 -AC composite dose was increased. The Langmuir isotherm model ( R 2 = 0 .97) showed better conventionality than the Freundlich model ( R 2 = 0 .80) with a maximum removal capacity of 303.03 mg/g at 318 K and pH 7.0. The kinetic results revealed that the equilibrium data well follow the pseudo-second-order model. The thermodynamic investigations indicated the spontaneous and endothermic removal of MG. The cycling test exhibited that the developed Zn(OH) 2 -AC composite had virtuous repeatable adsorption/desorption performance particularly until the fourth cycle. In addition to comparatively shorter adsorption time, relatively high adsorption capacity, reasonable reuse performance, and being of cost-effective and eco-friendly of the developed Zn(OH) 2 -AC composite make it economic, effective and hopeful adsorbent for cleaning MG containing wastewaters. • AC sorbent was produced from coffee waste with low cost material. • AC/zinc hydroxide nanoparticles composite was used to remove MG from aqueous solutions. • The dependency of the adsorption efficiency on the batch parameters was studied. • The maximum adsorption capacity was determined to be 303.03 mg g − 1 . • The synthesized adsorbent can be promising sorbent for MG elimination from wastewaters.

Study of removal Malachite Green dye from aqueous solution using snail shell powder as low-cost adsorbent

This research using snail shell (Rostellaria) powder to remove (Malachite Green ) dye from aqueous solution via adsorption. Experiments were conducted at 298 K to know the impact of initial concentration of Malachite Green, contact time, pH and effect of ionic strength. The optimum conditions for the adsorption of Malachite Green were realized at 0.0200 g of the adsorbent material . The maximum removal ratio was equal to 86.6585 % at 7.0000 mg/L,10 min as adsorption time and 298 K . Equilibrium adsorption isotherms was investigated. The empirical data were analyzed by the Langmuir, Freundlich and Temkin models of adsorption at different temperature change from (298 to 338) K. The adsorption isotherm data were suitability well to Langmuir isotherm. The calculated thermodynamics information of the adsorption process ΔG°, ΔH° and ΔS° refers that removal process occur via an adsorption process which features with spontaneous, exothermal and raise in the randomness of the molecules of the adsorbent dye,the obtained isotherms information from the experiments were conform For the type (S-curve) at Giles discretion.

APPLICATION OF BOX–BEHNKEN DESIGN FOR OPTIMIZATION OF MALACHITE GREEN REMOVAL FROM AQUEOUS SOLUTIONS BY MODIFIED BARLEY STRAW

&lt;p&gt;Untreated wastewater can have important effects on the environment and human. The aim of the work was to evaluate the effectiveness of modified barley straw to remove malachite green from industrial wastewater. Studied variables were pH, contact time, initial malachite green concentration, and adsorbent dosage. Box–Behnken design method was used for modeling the process of adsorption. The results of analysis of variance showed that there are the significance relative among process parameters. The high value of R2 (0.9753) indicated that there was a high correlation between the predicted and experimental values. Removal efficiency of malachite green increased by increasing of modified barley straw dosage, pH and contact time, and decreasing of color concentration. Remove the color was better in alkaline conditions and the best pH was equal to 9.5. The optimum contact time to remove was 120 min. The findings of this study showed that Box-Behnken model can efficiently optimize the malachite green adsorption onto modified barley straw from aqueous solutions.&lt;/p&gt;&#x0D;