Optimasi Pengaruh Waktu Kontak dan Dosis Adsorben Limbah Daun Kayu Putih (Melaleuca cajuputi) dengan Metode Isoterm Adsorpsi Langmuir

The prospective of maize cob powder (MCP) as an effective adsorbent for the removal of malachite green (MG) and congo red (CR) dyes from aqueous solution was investigated. The presence of functional groups and pores on maize cob powder were confirmed by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were examined to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of MG and CR onto the adsorbent (MCP) was found to be: contact time (60mins), pH (10.0) and temperature (303 K), adsorbent dose (1 g) for an initial MG dye concentration of 50 mg/L and contact time (80mins), pH (2.0) and temperature (343 K) for an initial CR dye concentration of 50 mg/L and adsorbent dose 1.0 g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for CR dye adsorption and Langmuir Isotherm for MG adsorption. The maximum adsorption capacity was found to be 13.02 mg/g and 9.41 mg/g for the adsorption of MG and CR dyes respectively. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) were evaluated and the negative values of ΔG0, ΔH0 and ΔS0 obtained indicated the spontaneous and exothermic nature of the MG adsorption process while positive enthalpy (ΔH0) indicated an endothermic nature of CR adsorption process.

The prospective of maize cob powder (MCP) as an effective adsorbent for the removal of malachite green (MG) and congo red (CR) dyes from aqueous solution was investigated. The presence of functional groups and pores on maize cob powder were confirmed by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were examined to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of MG and CR onto the adsorbent (MCP) was found to be: contact time (60mins), pH (10.0) and temperature (303 K), adsorbent dose (1 g) for an initial MG dye concentration of 50 mg/L and contact time (80mins), pH (2.0) and temperature (343 K) for an initial CR dye concentration of 50 mg/L and adsorbent dose 1.0 g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for CR dye adsorption and Langmuir Isotherm for MG adsorption. The maximum adsorption capacity was found to be 13.02 mg/g and 9.41 mg/g for the adsorption of MG and CR dyes respectively. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) were evaluated and the negative values of ΔG0, ΔH0 and ΔS0 obtained indicated the spontaneous and exothermic nature of the MG adsorption process while positive enthalpy (ΔH0) indicated an endothermic nature of CR adsorption process.

Response surface methodology optimization for sorption of malachite green dye on sugarcane bagasse biochar and evaluating the residual dye for phyto and cytogenotoxicity

As with the rest of the production, the Batik industry hurts people's lives due to dyes. When discharged into the river, this dye will directly cause environmental pollution, one of which is the disruption of photosynthesis of aquatic plants and can cause disease for living things. Therefore, it is necessary to make efforts to overcome this. This study aims to determine the effect of adsorbent time variation and dose variation on methylene blue and malachite green adsorption. Adsorption is the absorption of solution molecules that occur on an adsorbent surface. The adsorbent used is Eucalyptus distillation leaf waste with KOH activation treatment using the Freundlich and Langmuir adsorption isotherm model. The measurement method uses UV-Vis spectrophotometry to analyze methylene blue and malachite green levels at the maximum wavelength. The results showed that the best % removal to adsorb methylene blue was 52.84% and malachite green 88.03% at a dose of 0.2 gram, and the optimum contact time to adsorb malachite green and methylene blue was 20 minutes. The adsorption Model in this study followed the Isotherm of Freundlich and Langmuir adsorption on malachite green with R2 of 0.872 and 0.612 for non-activation and 0.964 and 0.095 for KOH activation, while methylene blue obtained 0.636 and 0.143 for non-activation and 0.850 and 0.545 for KOH activation. Based on the study results, it was concluded that the distillation of Eucalyptus leaf waste is more effective in adsorbing malachite green.

This study aimed to synthesize a hydrogel based on the Hing gum, grafted with acrylamide, for the adsorption of Malachite Green (MG) dye. Graft copolymers were optimized using a full factorial model in combination with response surface methodology and microwave irradiation to achieve maximum swelling. The optimized parameters comprised an initiator concentration of [Formula: see text] [Formula: see text]mol[Formula: see text]L[Formula: see text], a monomer concentration of [Formula: see text] [Formula: see text]mol[Formula: see text]L[Formula: see text], and a solvent volume of 13[Formula: see text]mL, resulting in a maximum swelling capacity of 760%. The statistical adequacy of the model was validated through ANOVA. The synthesized hydrogel was characterized using Fourier-transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, thermogravimetric analysis, zeta potential analysis, and Brunauer–Emmett–Teller theory. Its adsorption efficiency for MG dye was systematically investigated under various conditions, including contact time (1–6[Formula: see text]h), pH (2–9), adsorbent dosage (0.2–1.0[Formula: see text]g/L), and temperature (25–55[Formula: see text]C). The hydrogel demonstrated significant efficacy in eliminating cationic MG dye from aqueous solutions, achieving an adsorption rate of approximately 97% within 6[Formula: see text]h at room temperature. The adsorption efficacy was evaluated by adsorption kinetics and isotherm models. The findings demonstrated that the pseudo-second-order kinetic model and the Langmuir isotherm model provide the most accurate representation of the dye adsorption process. These findings underscore the hydrogel’s significant adsorption ability and its potential as an economical and eco-friendly method for eliminating MG dye from polluted water sources.

Grafting of copolymer of sodium acrylate (SA) and acrylamide (Am) onto pectin (Pcn) was successfully performed in order to synthesis Pcn-g-P(Am-co-SA) hydrogel using combined microwave-assisted method and potassium persulfate (KPS) as a free radical initiator. The prepared hydrogel was characterized by FTIR, SEM and TGA. This hydrogel was used to remove malachite green (MG) dye from aqueous solutions. The swelling ratio of the best grade of hydrogel was 214 g/g at pH (7). Factors affecting MG dye adsorption on hydrogel (grafting percentages, pH, contact time, hydrogel dosage, dye initial concentration and temperature) were studied, and the reusability study was also investigated which, in turn, showed the high adsorption capacity of hydrogel for MG dye. The adsorption data were fitted well with Langmuir adsorption isotherm model proposing the formation of monolayer of MG dye molecules on the hydrogel’s surface with maximum adsorption capacity (5000 mg/g). Moreover, the thermodynamic studies indicated the spontaneity and exothermic nature of adsorption of MG dye on hydrogel. From the reusability study, it was found that the prepared hydrogel still retains good adsorption properties after eleven successive cycles. Therefore, Pcn-g-P(Am-co-SA) hydrogel was considered as a highly potential adsorbent for MG dye removal from aqueous solutions.

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

Malachite green dye is widely used in the textile industry. Wastewater contaminated with malachite green dye threatens aquatic life and human health. Therefore, adsorption is needed in the dye waste treatment process. This research aims to synthesize magnetic carboxymethyl chitosan as an adsorbent for malachite green dye. Magnetic carboxymethyl chitosan was synthesized via a coprecipitation method and analyzed using FTIR. Batch experiments were used to study the adsorption of malachite green dye under adsorption parameters, such as the effects of pH and time, adsorption kinetics, isotherms, and reusability. The research results show that at pH 4, malachite green adsorbed most effectively into magnetic carboxymethyl chitosan. The pseudo-second-order kinetic model and the Langmuir adsorption isotherm model describe the adsorption process. Reduction for malachite green chitosan, carboxymethyl chitosan, and magnetic carboxymethyl chitosan were 34.19, 83.24, and 91.34%, respectively.

A study on the synthesis of magnetized adsorbents from coal fly ash (FA) for the adsorption of malachite green (MG) dye has been conducted. The method involves acid activation and ferrite magnetization of FA. The activation of FA was performed by mixing it in an HCl solution, while the magnetization was carried out by the coprecipitation method using the molar ratio of 1:2 of Fe2+/Fe3+. The magnetized coal fly ash adsorbent (FA/Fe3O4) was then utilized to adsorb the MG dye, and the results were compared with that adsorbed by activated fly ash (AFA). Characterization of the materials was carried out using Atomic Absorption Spectroscopy (AAS), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), and Vibrating Sample Magnetometer (VSM). The optimized parameters in the adsorption study were pH, adsorbent mass, contact time, and initial concentration. The optimum conditions for the adsorption of MG dye with AFA and FA/Fe3O4 are obtained at pH 7, the adsorbent mass of 0.1 and 0.25 g respectively, a contact time of 45 minutes, and the initial concentration of MG dye of 175 ppm. The MG adsorption on both adsorbents follows a pseudo-second-order kinetic model and can be best described by the Langmuir isotherm adsorption model. The synthesized adsorbent is prospective as it is low cost and easily separable from the solution using an external magnet after adsorption. Keywords: Adsorption, coal fly ash, magnetite, malachite green

This paper presents a review of adsorption isotherms of some dyes from aqueous solutions by biomaterial. In this paper, we reported Typha waste as a model of biomaterial classified as a low-cost adsorbent. The paper also briefly discusses about the literature information from the definition of dyes and adsorbents, bibliometric analysis, adsorption phenomena, adsorption isotherm models, and factors affecting the adsorption, to the use of Typha species waste as a low-cost adsorbent. The operational parameters factors are explained in terms of pH, adsorbent dosage, contact time, and initial dye concentration that will affect the process of removing textile dye. The solution of pH turns out to be the most important condition in the adsorption process for anionic dye, a low pH value are preferable in contrast to cationic dye where the suitable pH value is high. For the adsorbent dose, the adsorption capacity increase along with the increment of adsorbent dosage due to the increase of theavailable amount of adsorption site. The contact time between the adsorbent and dye affects the efficiency of dye removal where a strong attraction force will shorten the time. As for the effect of dye initial concentration, increasing the initial concentration enhances the increment of adsorbent surface area to adsorb dyes. Several isotherm models are described. The Langmuir model is frequently used to evaluate the adsorption capacity of the Typha species waste as adsorbents. This review paper suggested that the accuracy level obtained from adsorption processes is greatly dependent on the successful modeling of adsorption isotherms. Typha biomaterial wastes can be considered as the new useful low-cost natural adsorbents for dye clean-up operations in aquatic systems.

Synthesis and characterization of MOF-5 incorporated waste-derived siliceous materials for the removal of malachite green dye from aqueous solution

This research explores the feasibility of using date seeds (DS), an agricultural waste, for the adsorption of malachite green (MG) dye from synthesized wastewater. The characterization of the DS before and after adsorption was accomplished by FTIR, SEM, BET, and EDX measurements. Batch adsorption experiments were investigated for MG dye adsorption from aqueous solution onto the DS. The effect of different parameters such as solution pH, adsorbent dose, contact time, temperature, and the initial dye concentration were studied. The optimum pH, adsorbent dose, temperature, and contact time for the dye removal were found to be 5, 0.1 g, 25 °C, and 30 min, respectively. The equilibrium studies for the data with Langmuir, Freundlich, and Temkin isotherms showed that Freundlich isotherm is the best model to describe the adsorption of MG onto the DS particles which has a heterogeneous surface. It was found that the adsorption process follows a pseudo-second-order kinetic model which revealed that the intra-particle diffusion stage is the rate-controlling stage for the process. The thermodynamic parameters ΔG, ΔS, and ΔH suggest the possibility of chemisorption and physisorption simultaneously and indicate the exothermic and spontaneous characters of the adsorption of MG dye on DS with negative values of ΔH and ΔG.

In this study, the crosslinking of PVA nanofiber was increased using solvent vapor treatment. Then, Fe3O4 nanoparticles were synthesized by a simple hot water technique and composited with the nanofiber. The study focuses on applying the modified PVA nanofibers to remove malachite green (MG) from water using different pH, contact times, and dye initial concentrations. The surface morphology of the nanofiber was determined using SEM, FTIR, and XRD techniques. SEM showed that the crosslinking was increased, and Fe3O4 nanoparticles appeared as agglomerates on the surface of the nanofiber. The removal percentages at optimal pH and contact time were 99.76%, and 99.5%, respectively. Thereafter, kinetics was studied by the linear pseudo-first order, pseudo-second order, Elovich equation, and Intraparticle diffusion models. Results demonstrated that the adsorption kinetics follow the pseudo-second order. Moreover, the adsorption isotherm was discussed using Langmuir and Freundlich equations. The Langmuir equation best described the adsorption with R2 value of 0.9771, and the maximum removal was 128.205 mg/g. As a result, the MG dye molecules covered the PVA nanofiber/Fe3O4 nanoparticles in a monolayer and homogenous coverage. The results of this study are significant for industries' wastewater treatment as they provide a potential solution for the removal of MG dye from textile, paper, cosmetics, food, and aquaculture industries' wastewater.

In the present work, effect of different fuels on the structural, morphological, magnetic, adsorptive and photocatalytic properties of ferric oxide nanoparticles (Fe2O3 NPs) was evaluated. Fe2O3 NPs were synthesized via combustion method by using oxalyl dihydrazide (ODH), polyethylene glycol (PEG) and urea as fuels. The indigenously synthesized NPs were characterized by different analytical tools. XRD patterns confirmed the presence of α- and γ-Fe2O3 phases. TEM micrographs displayed average particle size was less than 30 nm. Saturation magnetization amplified with increase in the γ-Fe2O3 content, which was correlated to the fuel used for synthesis. Adsorptive and photocatalytic activity of synthesized NPs was studied using malachite green (MG) dye as a model compound. The uptake behavior for MG dye was influenced by the solution pH, contact time, adsorbent dose, temperature and dye concentration. Thermodynamic studies indicated the endothermic nature of the adsorption phenomenon. The adsorption was well defined with Langmuir and Freundlich isotherms in comparison to Dubinin-Radushkevitch adsorption isotherm model. The trend for percentage removal of MG dye using NPs synthesized by different fuels was: urea > PEG > ODH. Fe2O3 NPs facilitated photo degradation of dye solution in ultra-violet and visible light irradiations.

Chemically prepared activated carbon derived from durian seed (DSAC) was used as adsorbent to adsorb Malachite green (MG) dye. The prepared DSAC was characterized using Brunauer–Emmet–Teller (BET), Fourier transform infrared (FTIR), scanning electron microscope (SEM), and proximate analysis, respectively. Batch adsorption studies were carried out for the removal of MG dye from aqueous solutions by varying operational parameters like contact time, initial MG dye concentration, solution temperature, and initial solution pH. Maximum dye removal of 97 % was obtained at pH 8. Experimental data were analyzed by eight model equations—Langmuir, Freundlich, Temkin, Dubinin–Radushkevich, Radke–Prausnitz, Sips, Vieth–Sladek, and Brouers–Sotolongo isotherms—and it was found that the Freundlich isotherm model fitted the adsorption data the most. Adsorption rate constants were determined using pseudo-first-order and pseudo-second-order rate equations, Elovich, intraparticle diffusion, and Avrami kinetic model. The results clearly showed that the adsorption of MG dye onto DSAC followed the pseudo-second-order model, and the mechanism of adsorption was controlled both by film diffusion and intraparticle diffusion. Thermodynamic parameters such as ∆G, ∆H, and ∆S were also calculated for the adsorption process. The process was found to be spontaneous and endothermic in nature. This work provided an attractive adsorbent for the removal of MG dye from wastewaters.