Adsorption of 2,4-dichlorophenoxyacetic acid by mesoporous activated carbon prepared from H3PO4-activated langsat empty fruit bunch (original) (raw)
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Chemical Industry, 2019
Lagenaria vulgaris activated carbon (LVAC) was synthesized from Lagenaria vulgaris biomass by treatment with diluted H2SO4 followed by thermo-chemical carbonization and overheated steam activation process and used for removal of the herbicide 2,4-dichlo-rophenoxyacetic acid (2,4-D). Fourier transform infrared spectroscopy (FTIR) indicated that 2,4-D is adsorbed in micropores of the very porous LVAC (665 m2 g-1). LVAC showed high sorption capacity as compared to many previously used sorbents at optimal conditions: the stirring rate of 300 rpm, the sorbent dose of 1.0 g dm-3 and pH from 2 to 7. The experimental maximum sorption capacity of LVAC was 333.3 mg g-1. The pseudo-second-order model and Chrastil model described the 2,4-D sorption kinetics by LVAC. Thermodynamic studies have indicated that the sorption process was endothermic, spontaneous and physical in nature. LVAC was shown to be an ultrahighly efficient sorbent for removal of 2,4-D from groundwater, which could be also rec...
Adsorption study of 2,4-dichlorophenoxyacetic acid (2,4-D) from aqueous solution using commercial coconut activated carbon (CAC) as adsorbent has been carried out in batch experiments revealed that the equilibrium data were fitted to Langmuir, Freundlich and Temkin isotherm models and were found to be best represented by the Langmuir isotherm model; with maximum monolayer adsorption capacity of 300 mg/g at 30°C when the initial concentration was 50–300 mg/L. At the same time a fixed-bed adsorption study of 2,4-D from aqueous solution using CAC as adsorbent has been achieved using fixed-bed column where the effects of important factors such as the initial 2,4-D concentration, flow rate and bed height on the breakthrough characteristics of the adsorption system were evaluated. The results obtained confirmed that the breakthrough curves were dependent on initial pesticide concentrations, flow rate and bed height with the highest bed capacity of 50 mg/g at 150 mg/L initial 2, 4-D concen...
2021
In the present study, zinc chloride followed by acid treating was employed for fabrication activated carbon with a high surface area from pomegranate husk (APHAC) for 2,4-dichlorophenol (2,4-DCP) adsorption. The APHAC was a well-developed pore and exhibiting specific surface areas of 1576 m2/g. Based on the XRD analysis, the diffraction peaks between 15 ° and 35 ° corresponded to amorphous carbon, and the pHpzc values of APHAC was 6.15 ± 0.15. According to batch experiments, the optimum adsorption condition of 2,4-DCP was pH of 3, contact time 60 min, and APHAC dose of 1.75. The absorption capacity of 2,4-DCP at the APHAC dose of 0.5 promptly decreased from 259.5 ± 12.9 mg/g at the initial concentration of 150 mg/L to 74.5 ± 3.7 mg/g dose of 2 g/L. With increasing temperature from 10°C to 50°C, the adsorption efficiency declined from 99.8 ± 0.5% to 75.6 ± 1.89%. The isotherm and kinetic of 2,4-DCP by APHAC revealed that Freundlich and Elovich satisfactorily fitted with experimental ...
Adsorption equilibrium, kinetic of 2,4-dichlorophenoxy-acetic acid (2,4-D), one of the most commonly used phenoxy acid herbicides, onto different adsorbents such as granular activated carbon (GAC) and synthetic polymeric adsorbents XAD-7HP, XAD-1180 and XAD-4 were studied in aqueous solution in a batch system. Langmuir isotherm model was applied to experimental equilibrium data of 2,4-D adsorption depending on adsorbents used. Equilibrium data fitted very well to the Langmuir equilibrium model in the studied concentration range of 2, 4-D for all the adsorbents studied. Adsorption using GAC is very rapid in the first hour of contact where 70-80 % of the adsorbate is removed by GAC followed by a slow approach to equilibrium, whereas in case of polymeric adsorbents 60-65 % of the adsorbate is removed in the first 30 min which is then followed by a slow approach to equilibrium.
Desalination and Water Treatment, 2013
ABSTRACT The current study aims to utilize activated carbon produced from agriculture waste to adsorb and remove malathion and profenofos as organophosphorous insecticides from aqueous solutions under different experimental conditions. Physicochemical properties of these materials were investigated by several procedures; elemental analysis, surface area, and texture porosity. A matrix effect analysis was applied to correlate the malathion and profenofos adsorption capacity to the agitation time, initial levels of each pesticide (1-10mg/l), carbon dose (50-100mg), pH (3-11), and different temperatures (15-45 degrees C). The maximum removal percentages of malathion and profenofos at equilibrium time were 97 and 98% for activated carbon derived from date stones (AC1), respectively, however, these values were 98 and 96% for Norit carbon as a reference carbon (AC2). At equilibrium time,the increase of temperature decreased the adsorption capacity of both AC1 and AC2 with malathion and profenofos. The adsorption capacity of both AC1 and AC2 to malathion and profenofos increased as the pH was increased.
Molecules, 2020
A facile eco-friendly approach for acetampirid pesticide removal is presented. The method is based on the use of micro- and mesoporous activated carbon (TPAC) as a natural adsorbent. TPAC was synthesized via chemical treatment of tangerine peels with phosphoric acid. The prepared activated carbon was characterized before and after the adsorption process using Fourier- transform infrared (FTIR), X-ray diffraction (XRD), particle size and surface area. The effects of various parameters on the adsorption of acetampirid including adsorbent dose (0.02–0.2 g), pH 2–8, initial adsorbate concentration (10–100 mg/L), contact time (10–300 min) and temperature (25–50 °C) were studied. Batch adsorption features were evaluated using Langmuir and Freundlich isotherms. The adsorption process followed the Langmuir isotherm model with a maximum adsorption capacity of 35.7 mg/g and an equilibration time within 240 min. The adsorption kinetics of acetamiprid was fitted to the pseudo-second-order kinet...
Annales de Chimie Science des Matériaux, 2001
Aromatic hydrocarbons such as 2,4-dichlorophenoxyacetic acid (2,4-D), a common herbicide, is often found in groundwater in areas with intensive agricultural activities. Even in minute concentration, they are known to affect human health. An attempt has been made to capture 2,4-D from aqueous medium using neemoil-phenolic resin treated lignocellulosic jute. Treated jute showed 84% 2, 4-D removal efficiency. The 2,4-D removal of the biosorbent was confirmed from FTIR and 13 C NMR analyses. The adsorption process was found to be spontaneous and effective over a pH range between 2 and 8. Maximum 2,4-D removal capacity of treated jute was found to be 38.5 mg/g. Treated jute was found to remove 2,4-D from aqueous media economically and efficiently through polar-polar and non-polar-non polar interactions. No sludge was produced during 2,4-D removal with treated jute nor did the process introduce deleterious characteristics, e.g ., hardness and odor to the treated water.
Adsorption equilibrium and kinetics of 2,4-dichlorophenoxyacetic acid (2,4-D) and carbofuran using commercial granular activated carbon, Filtersorb 300 (GAC F300) were studied in a batch system with respect to initial concentration of 2,4-D and carbofuran. The Langmuir and the Freundlich isotherm models were applied to the equilibrium data of 2,4-D and carbofuran adsorption. Observed results showed that the equilibrium data fitted well to the Langmuir equilibrium model in the studied concentration range of 2,4-D and carbofuran. The monolayer adsorption capacities of GAC F300 were 181.82 and 96.15 mg/g for 2,4-D and carbofuran, respectively. Two simplified models, pseudo-first order and pseudo-second order kinetic, were used to test the adsorption kinetics of 2, 4-D and carbofuran on GAC F300. The data was best fitted to the pseudo-second-order kinetic model
Sky fruit husk as low-cost agricultural waste to produce activated carbon (SFHAC). The BET surface area of the produced SFHAC is 1211.57 m 2 /g. The monolayer maximum adsorption capacity of the SFHAC for herbicide bentazon was 166.67 mg/g. a b s t r a c t The present study utilized an agricultural low cost biomass sky fruit husk for the preparation of activated carbon by chemical activation with orthophosphoric acid (H 3 PO 4) and later characterized by N 2 adsorp-tion–desorption isotherms, scanning electron microscopy (SEM) and Fourier transform infrared spectros-copy (FTIR). Batch adsorption process was followed in order to evaluate the potentiality of the prepared activated carbon having BET surface area of 1211.57 m 2 /g for the removal of anionic herbicide bentazon from aqueous solution. The effects of initial concentration, contact time and pH has been studied. The adsorption study indicates that the adsorption data followed the Freundlich model better than the Lang-muir which suggested the heterogeneous nature of the activated carbon surface. The monolayer maximum adsorption capacity of the sky fruit husk activated carbon (SFHAC) was found to be 166.67 mg/g. Kinetic data fitted better to the pseudo-second order model and intraparticle diffusion phenomenon indicated more than one process is regulating the adsorption process. The thermodynamic parameters associated with the adsorption process, standard free energy change (DG°), enthalpy change (DH°) and entropy change (DS°) were also determined at different temperatures and adsorption process was found to be endothermic in nature.
Engenharia Sanitaria e Ambiental
The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has been detected in water bodies worldwide, precluding their use for water supply. Despite this, scientific studies assessing the behavior of herbicides in water treatment systems are scarce, which motivated this study on 2,4-D removal. 2,4-D removal and its relationship with absorbance were investigated using a pilot system comprising coagulation, sedimentation, filtration, granular activated carbon (GAC) adsorption, and chlorinated disinfection. 2,4-D removal ranged from 15 to 64% after sedimentation, from negative values to 19% after filtration, and from 5 to 16% after chlorination, with total removal rates of 19 to 70%. Breakthrough curves showed an adsorption capacity of 0.70 mg g−1 GAC for a C/C0 ratio of 0.50 and a VTW/VGAC ratio of 3.598 for a breakthrough concentration of 30 ± 3 μg L−1. The positive correlation between absorbance and 2,4-D (R2 = 0.78) in the GAC column effluent indicated that absorbance can be used for e...