Adsorption Of Bentazone Research Articles

Pulsed-sonochemiluminescence combined with molecularly imprinted polymerized high internal phase emulsion adsorbent for determination of bentazone.

A small low-power humidifier with a simple programmable on/off switch was used as a pulsed ultrasound generator. Using this tool, a novel sonochemiluminescence (SCL) method was developed to determine bentazone. To the best of our knowledge, no chemiluminescence method has been proposed to determine this pesticide. Only five studies have been proposed for SCL quantitative applications so far. Therefore, revealing new aspects of SCL promises to develop analytical methods for the quantitative determination of different substances. A molecularly imprinted polymerized high internal phase emulsion (MIP-polyHIPE) was synthesized, bentazone separated from aqueous solutions, and pre-concentrated by the MIP-polyHIPE foam. The adsorption of bentazone on the MIP-polyHIPE adsorbent was theoretically studied by density functional theory through molecular dynamics simulation. Both experimental and simulation results indicated removal and pre-concentration of bentazone by the MIP-polyHIPE adsorbent. Using the proposed SCL method and without pre-concentration process, a linear dynamic range (LDR) of 2.5 × 10-7-5.0 × 10-5mol L-1 and a limit of detection (LOD) of 8.4 × 10-8mol L-1 were obtained for bentazone with a relative standard deviation of 2.64%. The LDR and LOD were improved to 2.6 × 10-9-2.0 × 10-7mol L-1 and 8.8 × 10-10mol L-1, respectively, using MIP-polyHIPE adsorbents. The method's application was evaluated by removing and pre-concentration of bentazone from water samples, including well, river, and tap water. The results showed that the pre-concentration factor and recovery percentages were 113-131 times and 93-106%, respectively, using the MIP-polyHIPE absorbent.

Adsorption of bentazone in the profiles of mineral soils with low organic matter content.

The current laboratory adsorption study aimed at determination of the values of adsorption distribution coefficient (Kd) of bentazone in the profiles of Arenosols, Luvisols, and Cambisols, which are the most common arable mineral soils in Poland. The study attempted to identify the soil components that bind bentazone and the principal adsorption mechanisms of this compound as well as create a model capable of predicting its adsorption in soils. The Kd values determined in batch experiments after 24 h of shaking were very low, and ranged from 0.05 to 0.30 mL/g for the Ap horizon and 0 to 0.07 mL/g for subsoils. The results indicated that the anionic form of bentazone was adsorbed on organic matter, while in acidic soils the neutral form of bentazone was adsorbed on organic matter and sand. The detailed analyses of mineralogical composition revealed that the principal mineral that was responsible for the adsorption of bentazone was quartz, which content was strongly positively correlated with the sand fraction. In soils with pH < 5 and an organic carbon content of < 0.35%, quartz exhibited much greater affinity for the neutral bentazone form than organic matter. Fourier transform infrared photoacoustic spectroscopy analyses supported by computational methods have shown the most probable mechanisms behind the adsorption of bentazone on quartz. The created model, assuming the adsorption of bentazone on organic matter and on sand and using the spectrophotometrically determined dissociation constant of bentazone, very well explained the Kd variance in the 81 examined soils, while correctly predicting the adsorption based on soil properties described in the published data.

Amyloid Fibrils Aerogel for Sustainable Removal of Organic Contaminants from Water.

Water contamination by organic pollutants is ubiquitous and hence a global concern due to detrimental effects on the environment and human health. Here, it is demonstrated that amyloid fibrils aerogels are ideal adsorbers for removing organic pollutants from water. To this end, amyloid fibrils prepared from β-lactoglobulin, the major constituent of milk whey protein, are used as building blocks for the fabrication of the aerogels. The adsorption of Bentazone, Bisphenol A, and Ibuprofen, as model pollutants, is evaluated under quasi-static conditions, without use of energy or pressure. Through adsorption by amyloid fibrils aerogel, excellent removal efficiencies of 92%, 78%, and 98% are demonstrated for Bentazone, Bisphenol A, and Ibuprofen, respectively. Furthermore, the maximum adsorption capacity of amyloid fibrils aerogel for Bentazone, Bisphenol A, and Ibuprofen is 54.2, 50.6, and 69.6 mg g-1 , respectively. To shed light on the adsorption equilibrium process, adsorption isotherms, binding constants, saturation limits, and the effect of pH are evaluated. Finally, the regeneration of the aerogel over three consecutive cycles is studied, exhibiting high reusability with no significant changes in its removal performance. These results point at amyloid fibrils aerogels as a sustainable, efficient, and inexpensive technology for alleviating the ubiquitous water contamination by organic pollutants.

Adsorption of bentazone and imazapyc from water by using functionalized silica: Experimental and computational analysis

In this study, silica and functionalized silica materials (3-aminopropyl and 3-mercapto derivatives) were successfully used for the removal of the pesticides bentazone and imazapyc from aqueous solutions. Adsorbent materials were characterized by BET isotherms and FT-IR spectroscopy (confirming the functionalization), and their equilibrium adsorption capacity was evaluated at different ionic strengths. It is observed that the maximum adsorption capacities decrease in the order 3-aminopropyl-derivative > silica >3-mercaptopropyl derivative. An increase in ionic strength produces an enhancement in the removal of pesticides. All isotherms are Ib-type and follow the Langmuir model, suggesting a monolayer physical adsorption process.

Adsorption of bentazon on CAT and CARBOPAL activated carbon: Experimental and computational study

Abstract Removal of the bentazon by adsorption on two different types of activated carbon was investigated under various experimental conditions.Kinetics of adsorption is followed and the adsorption isotherms of the pesticide are determined. The effects of the changes in pH, ionic strength and temperature are analyzed. Computational simulation was employed to analyze the geometry and the energy of pesticide absorption on activated carbon. Concentration of bentazon decreases while increase all the variables, from the same initial concentration. Experimental data for equilibrium was analyzed by three models: Langmuir, Freundlich and Guggenheim–Anderson–de Boer isotherms. Pseudo-first and pseudo-second-order kinetics are tested with the experimental data, and pseudo-second-order kinetics was the best for the adsorption of bentazon by CAT and CARBOPAL with coefficients of correlation R2 = 0.9996 and R2 = 0.9993, respectively. The results indicated that both CAT and CARBOPAL are very effective for the adsorption of bentazon from aqueous solutions, but CAT carbon has the greater capacity.

Adsorption of bentazon on two kinds of granular activated carbons: equilibrium, kinetic and thermodynamic studies

The adsorption of bentazon on two types of granular activated carbons (GACs), VRU F36X16 (VRU) and WS-480 (WS) from aqueous solution was evaluated by kinetics, isotherms, and thermodynamic models in this study. The impacts of initial bentazon concentration, temperature, and initial solution pH were also investigated. The equilibrium adsorption capacity (qe) of each GAC was appreciable under the experimental condition, especially VRU. For either GAC, the adsorption process fitted pseudo-second-order equation best and statistics matched two-step intra-particle diffusion model well. Dubinin–Radushkevich model was the most suitable one for bentazon adsorption on VRU, while Redlich and Peterson model best described bentazon adsorption on WS. Both for VRU and WS, the adsorption process was exothermic and belonged to physisorption. The qe of VRU and WS increased as initial bentazon concentration increased, though the removal rate of bentazon decreased. 25°C was the optimal condition for bentazon adsorption on either GAC, while the qe of both GACs dropped as the temperature increased. Although the increase in pH could hinder bentazon adsorption on GACs significantly, there was a slight change in the adsorption capacities of VRU and WS when initial solution pH was in the range 5–9.

Adsorption of Pesticides with Different Chemical Properties to a Wood Biochar Treated with Heat and Iron

Biochars are known to affect the environmental fate of pesticides when used as soil amendments and have been suggested to be useful as cheap adsorbents of organic contaminants. We studied the ability of a wood-based biochar produced by slow pyrolysis from a mixture of about 80 % hardwood (Betula sp.) and 20 % softwood (Picea abies) to adsorb pesticides in order to assess its potential use as a filter material to prevent point source pollution in agriculture. The pesticides bentazone, chlorpyrifos, diuron, glyphosate and (4-chloro-2-methylphenoxy)acetic acid (MCPA) were used as model compounds. Their adsorption and desorption to the biochar were tested before and after it had been subjected to treatments with heat and/or iron intended to enhance its adsorptive properties. The adsorption affinity of the native biochar, as indicated by the Freundlich K F value, varied greatly and decreased in the order diuron > chlorpyrifos > MCPA > bentazone > glyphosate. Activation with heat (t = 450 °C) increased the specific surface area and the wettability of the biochar, measured by a water drop penetration time assay, and increased the adsorption of bentazone and MCPA. Treatment with iron salts, which partially coated the biochar with an iron oxide identified as magnetite, decreased the specific surface area but increased the adsorption of glyphosate. Mixing biochar fractions subjected to different treatments was a successful approach for optimising the adsorption of all model compounds and could be a viable path for creating a versatile yet comparably cheap filter material.

Preparation, characterization and application of a CTAB-modified nanoclay for the adsorption of an herbicide from aqueous solutions: Kinetic and equilibrium studies

Abstract In this study, surfactant-modified pillared montmorillonites (MMT) were prepared using cetyltrimethylammonium bromide (CTAB) by the intercalation method and used as adsorbent to remove bentazon from aqueous solutions. The main compositions of MMT and CTAB/MMT were characterized by Fourier transform–infrared spectroscopy (FT–IR), X-ray diffraction (XRD), scanning electron micrography (SEM) and energy dispersive X-ray (EDX) spectroscopy. The removal efficiency of bentazon was studied as a function of adsorbent dosage, pH, initial bentazon concentration and ionic strength (sodium carbonate, sodium bicarbonate, sodium sulfate and sodium chloride). The removal efficiency of bentazon by CTAB/MMT was more than that of MMT in similar conditions. By increasing adsorbent dosage and initial bentazon concentration, the removal efficiency was increased and declined, respectively. The results showed that the maximum adsorption of organo-modified montmorillonite was obtained at pH 3. The maximum adsorption capacity was estimated to be 500 mg/g at pH 3 and room temperature. The study of the adsorption kinetic model revealed that the pseudo-second order model was the best applicable one to describe the adsorption of bentazon onto CTAB/MMT. Adsorption data were analyzed by both Langmuir and Freundlich adsorption isotherms and the results showed that it was better described by the Langmuir model. The adsorption capacities of the samples were found to increase with Na2CO3 anion saturation, while they decreased in the presence of NaHCO3, Na2SO4 and NaCl.

English

In this study, the efficiency of activated carbon produced from Henna wood was studied to remove herbicide from aqueous solutions by adsorption. The parameters that affect the adsorption such as contact time, activated carbon dosage, initial concentration of adsorbate, stirring rate, temperature, and pH on bentazon adsorption were studied. The use of Henna wood as a raw material to produce activated carbon by physical activation was investigated. The activated carbons produced were characterized by nitrogen adsorption isotherms and point of zero charge properties. Brunauer, Emmett and Teller (BET) surface area of the activated carbon was determined. The removal of herbicide from aqueous solutions by adsorption on activated carbon produced was studied. The results of the present investigation showed that activated carbons prepared from Henna wood have good adsorption capacity for the removal of bentazon from aqueous solution. The Langmuir model provides the best correlation of the experimental equilibrium data. Adsorption isotherm according to BET classification was of Type I. The adsorption isotherms of bentazon revealed that adsorption increased as the concentration increases up to a saturation point. Enthalpy, entropy and free enthalpy adsorption have a negative value indicating that the adsorption of bentazon on the Henna wood activated was feasible, spontaneous and exothermic at 20 to 40°C. Keywords: Activated carbon, adsorption, thermodynamic parameters, Henna wood, Bentazon. African Journal of Biotechnology , Vol 13(31) 3597-3606

Utilization of sky fruit husk agricultural waste to produce high quality activated carbon for the herbicide bentazon adsorption

Abstract The present study utilized an agricultural low cost biomass sky fruit husk for the preparation of activated carbon by chemical activation with orthophosphoric acid (H3PO4) and later characterized by N2 adsorption–desorption isotherms, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Batch adsorption process was followed in order to evaluate the potentiality of the prepared activated carbon having BET surface area of 1211.57 m2/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 Langmuir 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 (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°) were also determined at different temperatures and adsorption process was found to be endothermic in nature.

Batch study for herbicide bentazon adsorption onto branches of pomegranates trees activated carbon

The adsorption of herbicide bentazon from aqueous solution onto branches of pomegranates trees activated carbon (BPTAC) was investigated through batch study. The effects of both initial concentration and pH of the bentazon over the range of 25–250 mg/L and 2–12, respectively, on the adsorption of the prepared BPTAC were studied in batch experiments. Equilibrium data were fitted to the Langmuir, the Freundlich and the Temkin isotherm models. The results obtained from application of these models show that the best fits were achieved with the Langmuir model and a maximum monolayer adsorption capacity of 80 mg/g was obtained at 30°C. The regeneration efficiency of spent activated carbon was studied and it was found to be 92–96%. The results indicated that BPTAC has good capability as adsorbent for the removal of bentazon from aqueous solutions.

Adsorption of bentazon on activated carbon prepared from Lawsonia inermis wood: Equilibrium, kinetic and thermodynamic studies

The adsorption of bentazon onto Lawsonia inermis wood-based activated carbon (LWAC) was carried out in this work. The effects of different reaction parameters such as the initial bentazon concentration, contact time, activated carbon dosage, stirring rate, temperature and pH on bentazon adsorption were investigated in a batch process mode. Equilibrium data were analyzed by the Langmuir, Freundlich and Temkin isotherm model. Langmuir isotherm provided the best fit to the equilibrium data with maximum adsorption capacity of 169.49mg/g at 20°C. Adsorption kinetic was found to follow the pseudo-second-order kinetic model. The mechanism of the adsorption process was determined from the intraparticle diffusion model. The calculated thermodynamic parameters such as ΔG°, ΔH° and ΔS° showed that the adsorption of bentazon onto LWAC was feasible, spontaneous and exothermic at 20–40°C. Desorption of the used LWAC was studied using ethanol as solvent and a percent desorption efficiency of bentazon equalizes 73.8% was obtained after three cycles.

Bentazon and carbofuran adsorption onto date seed activated carbon: Kinetics and equilibrium

Date seed (DS), an abundant and inexpensive natural resource in Iraq, was used to prepare DS activated carbon (DSAC) by physiochemical activation with potassium hydroxide (KOH) and carbon dioxide (CO 2) as the activating agents at 850 °C for 3 h and 37 min. The adsorption kinetics and equilibrium of bentazon and carbofuran onto DSAC were examined in batch process. Adsorption studies were conducted in the pesticides initial concentration range of 25–250 mg/L, temperature of 30 °C and pH of 5.5. The pH studies were undertaken in the pH range 2–12. The adsorption kinetic data were analyzed by non-linear fitting using the pseudo-first-order and pseudo-second-order models. The adsorption of bentazon and carbofuran was better described by the pseudo-second-order equation. The experimental equilibrium data were analyzed by non-linear fitting using Langmuir and Freundlich isotherm models. Equilibrium data fitted better with the Freundlich model for both pesticides. DSAC showed higher adsorption in the case of carbofuran than for bentazon. Desorption of the used DSAC was studied using ethanol as solvent and percent desorption efficiencies of 84.1 and 82.2% were obtained after three cycles for bentazon and carbofuran, respectively. The high adsorption capacity of DSAC obtained for both pesticides showed that DS is a good precursor for the preparation of activated carbon for the adsorptive removal of bentazon and carbofuran.

Effect of preparation conditions of oil palm fronds activated carbon on adsorption of bentazon from aqueous solutions

Oil palm fronds (OPF) were used to prepare activated carbon (PFAC) using physiochemical activation method, which consisted of potassium hydroxide (KOH) treatment and carbon dioxide gasification. The effects of the preparation variables, which were activation temperature, activation time and chemical impregnation ratios (KOH: char by weight), on the carbon yield and bentazon removal were investigated. Based on the central composite design (CCD), two factor interaction (2FI) and quadratic models were, respectively, employed to correlate the PFAC preparation variables to the bentazon removal and carbon yield. From the analysis of variance (ANOVA), the most influential factor on each experimental design response was identified. The optimum conditions for preparing activated carbon from OPF were found as follows: activation temperature of 850 degrees C, activation time of 1h and KOH:char ratio of 3.75:1. The predicted and experimental results for removal of bentazon and yield of PFAC were 99.85%, 20.5 and 98.1%, 21.6%, respectively.

Mechanism of adsorption and electrosorption of bentazone on activated carbon cloth in aqueous solutions

An electrochemical technique has been applied to enhance the removal of a common herbicide (bentazone) from aqueous solutions using an activated carbon cloth as electrode. A pH increase from acidic to basic reduces the uptake, with capacities going from 127 down to 80 mg/g at pH 2 and 7, respectively. Increasing the oxygen content of the carbon cloth causes a decrease in the bentazone loading capacity at all pH values. This indicates that adsorption is governed by both dispersive and electrostatic interactions, the extent of which is controlled by the solution pH and the nature of the adsorbent. Anodic polarization of the carbon cloth noticeably enhances the adsorption of bentazone, to an extent depending on the current applied to the carbon electrode. The electrosorption is promoted by a local pH decrease provoked by anodic decomposition of water in the pores of the carbon cloth.

Adsorption of bentazon and propanil from aqueous solutions at the high area activated carbon-cloth

Removal of the pesticides bentazon and propanil from single and bisolute solutions by adsorption at the high area activated carbon-cloth was investigated. Kinetics of adsorption was followed and adsorption isotherms of the two pesticides were determined. A special V-shaped cell with an UV cuvette attached to it was used for adsorption studies. With this cell it was possible to follow the concentration of pesticide molecule by in situ UV spectroscopy as it is adsorbed at the carbon-cloth. It was found that concentration of pesticides decreased from the same initial concentration of 4.5 × 10 −5 to 1.1 × 10 −5 for bentazon and to 9.5 × 10 −6 for propanil in about 2 h. The fits of experimental adsorption isotherm data to Langmuir and Freundlich isotherm equations were almost equally successful. Monolayer capacities determined from Langmuir isotherms of pesticides showed that bentazon has greater monolayer capacity than propanil. This conclusion was also confirmed through the 1/ n parameter of Freundlich equation.

Atrazine, isoproturon, mecoprop, 2,4-D, and bentazone adsorption onto iron oxides.

Iron oxides are important components influencing the adsorption of various inorganic and organic compounds in soils and sediments. In this study the adsorption on iron oxides of nonionic and ionic pesticides was determined as a function of solution pH, ionic strength, and pesticide concentration. The investigated iron oxides included two-line ferrihydrite, goethite, and lepidocrocite. Selected pesticides comprised atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine), isoproturon [3-(4-isopropylphenyl)-1,1-dimethylurea)], mecoprop [(RS)-2-(4-chloro-2-methylphenoxy)propionic acid], 2,4-D (2,4-dichlorophenoxyacetic acid), and bentazone [3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide]. The adsorption of the nonionic pesticides (atrazine and isoproturon) was insignificant, whereas the adsorption of the acidic pesticides (mecoprop, 2,4-D, and bentazone) was significant on all investigated iron oxides. The adsorption capacity increased with decreasing pH, with maximum adsorption reached close to the pKa values. The addition of CaCl2 in concentrations from 0.0025 to 0.01 M caused the adsorption capacity to diminish. The adsorption of bentazone was significantly lower than the adsorption of mecoprop and 2,4-D, illustrating the importance of a carboxyl group in the pesticide structure. The adsorption capacity on the iron oxides increased in the order: lepidocrocite < goethite < two-line ferrihydrite. The maximum adsorption capacities of meco-prop and 2,4-D on goethite were found to be equivalent to the site density of singly coordinated hydroxyl groups on the faces of the dominant (110) form, suggesting that singly coordinated hydroxyl groups are responsible for adsorption. Differences in adsorption capacities between iron oxides can be explained by differences in the surface site density of singly coordinated hydroxyl groups. The maximum measured adsorption capacity of mecoprop on two-line ferrihydrite was equivalent to 0.2 mol/mol Fe.

Simulation of bentazon leaching in sandy loam soil from mellby (Sweden) with the pestla model

Abstract Results of a lysimeter study on bentazon leaching in a sandy loam soil from Mellby (Sweden) were used to test the PESTLA model. To obtain a good description of the measured amounts of drainage water, the potential evapotranspiration rate (based on the Penman equation) had to be multiplied by 1.5 to 2. This comparatively large increase in potential evapotranspiration is probably the result of the surroundings of the lysimeter being dry for most of the experimental period. Using sorption parameters estimated from literature data resulted in the calculated leaching of bentazon to be much higher than the measured leaching. Using sorption parameters based on measured bentazon adsorption to the sandy loam soil resulted in a good explanation of the observed leaching of bentazon by the model.