Adsorption Of Carbofuran Research Articles

The adsorption effects of biochar on carbofuran in water and the mixture toxicity of biochar-carbofuran in rats

Carbofuran, a widely used carbamate insecticide, is frequently detected in water. In this study, a high-performance adsorbent (WAB4) for carbofuran was obtained from laboratory-synthesized biochars. The maximum adsorption of carbofuran by WAB4 reaches 113.7 mg/g approximately. The adsorption of carbofuran by biochar was a multi-molecular layer and the adsorption process conforms to the pseudo-second-order kinetic model (R2 = 0.9984) and Freundlich isotherm model (R2 = 0.99). Importantly, an in vivo rat model was used to assess the combined toxicological effects of biochar-carbofuran complexes. The toxicity of the complexes (LD50 > 12 mg/kg) is lower than that of carbofuran (LD50 = 7.9 mg/kg) alone. The damage of biochar-carbofuran complex on rat liver and lung is significantly less than that of carbofuran. The Cmax and bioavailability of carbofuran were found to be reduced by 64% and 68%, respectively, when biochar was present, by UPLC-MS/MS analysis of carbofuran in rat plasma. Furthermore, it was confirmed that the biochar-carbofuran complex is relatively stable in the gastrointestinal tract, by performing a carbofuran release assay in artificial gastrointestinal fluids in vitro. Collectively, biochar is a bio-friendly material for the removal of carbofuran from water.

Diazotization-coupling reaction on aluminum-based metal–organic framework for efficient purification of wastewater from carbofuran pesticide

A crucial issue is the development of highly and selectively absorbable pesticides. At room temperature, aluminum-based metal–organic frameworks (MIL-53-NH2, MIL-53-AZA, MIL-53-AZA-La, and MIL-53-AZA-Ce) were successfully formed. Using prepared MOFs as sorbents, carbofuran was adsorbed from wastewater. Experimental and spectroscopic studies were used to investigate the elimination mechanisms. The current process can connect a mixture of pi- pi stacking contact, coordination bonding, and hydrogen bond production. The adsorption of carbofuran from wastewater was best described by pseudo-second-order kinetics and Langmuir isothermal models. MIL-53-NH2, MIL-53-AZA, MIL-53-AZA-La, and MIL-53-AZA-Ce had elimination capacities of 367.87, 433.50, 610.23, and 635.05 mg g-1, respectively. The synthesized MOFs are represented as promising materials for the removal of carbofuran.

Remarkable Separation of Carbofuran Pesticide from Aqueous Solution Using Free Metal Ion Variation on Aluminum-Based Metal-Organic Framework

The alarming increase in pesticide residues poses a major threat to aquatic and natural habitats. Therefore, it has become essential to design extremely operationally and economically advantageous systems for the removal of carbofuran pesticides from wastewater. Here, an aluminum-based metal-organic framework (MOF), MIL-53-NH2, and its modified forms, MIL-53-NH-ph, MIL-53-NH-ph-Fe, MIL-53-NH-ph-Zn, and MIL-53-NH-ph-Cu, have been successfully synthesized. Full characterization using IR, 1HNMR, XRD, and SEM was carried out. The prepared MOFs have been utilized as effective adsorbents for carbofuran in aqueous solutions. The various factors affecting the adsorption process (pH, time, and adsorbate concentration) were also investigated. Spectroscopic approaches were used to investigate the adsorption mechanisms. A mixture of π-π stacking contact, coordination bonding, and hydrogen bond formation can be connected to the current process. The adsorption of carbofuran from aqueous solutions was best described by pseudo-second-order kinetics and Langmuir equilibrium isotherm models. MIL-53-NH2, MIL-53-NH-Ph, MIL-53-NH-Ph-Fe, MIL-53-NH-Ph-Zn, and MIL-53-NH-Ph-Cu demonstrated adsorption capacities of 367.8, 462.1, 662.94, 717.6, and 978.6 mg g−1, respectively.

Evaluation of pollution of groundwater resources by Carbofuran based on its adsorption on three soils by Spectrophotometry

The adsorption studies of carbofuran on three natural soils of different characteristics were conducted under laboratory conditions at 20 and 30 ±1ºC with an objective to evaluate the risk of pollution of groundwater resources. An extractive spectrophotometric methodology based on the transformation of insecticide into methyl isobutyl ketone (MIBK), extractable yellow product absorbing at 380 nm has been developed for the purpose. Adsorption and mobility were found significantly correlated with each other and were greatly affected with organic matter and clay content of the soil. The adsorption study was carried out by batch equilibration procedure. Adsorption of carbofuran into the soil fits the Freundlich adsorption isotherm. This adsorption study has been observed to be a spontaneous and exothermic process. The measured adsorption coefficients were used to evaluate leaching potential in terms of Groundwater Ubiquity Score (GUS). The observed GUS values in the range between 2.71-3.22 indicated that the carbofuran acts as a leacher, thereby poses a potential risk to groundwater resources and therefore calls for its judicious use.

Irreversible sorption of carbofuran by moderately acidic soil amended with biochar

An ecofriendly technique to on farm burning of biomass by making biochar from agricultural waste was provided. Characteristic studies of biomass and biochar such as SEM, Ultimate and proximate analysis, pH, Cation exchange capacity, Water holding capacity, Electrical conductivity, Soil organic matter and Dry matter production were examined. Adsorption and desorption of carbofuran in soil were studied in batch experiment mode. From the experimental studies, it was observed that pH, Cation exchange capacity, Water holding capacity, Electrical Conductivity, Soil organic content and dry matter production increases with biochar addition. Adsorption Studies show that carbofuran adsorbed with control is 0.45 mg/g whereas with 3%BC it was 6.375 mg/g and desorption studies show that with 3% biochar carbofuran desorption is less. Hence Capsicum Annuam Biochar could be one of the promising option for improving the soil health as well as for adsorbing the pesticides.

Torrefied and unmodified capsicum annuam biochar for the removal of synthetic hazardous pesticide (carbofuran) from watershed

The present study explored the applicability of torrefied and unmodified Capsicum Annuam biochar (CABC) for the removal of carbofuran from its aqueous streams. The developed biochar at low temperature pyrolysis (300°C) attained a surface area and pore volume of 32.07 m^2⁄g and 0.064〖cm〗^3/g, respectively. The biochar was characterized for its physico-chemical transformation. It was observed that aromatic and hydroxyl groups present in the CABC were responsible for the sorption of carbofuran. The efficacy of carbofuran removal was examined by varying the process variables such as carbofuran concentration, sorption time, pH and adsorbent dosage. The investigation on isothermal models suggested a monolayer adsorption of carbofuran onto homogeneous surface of CABC. While the sorption kinetics is chemical rate controlling mechanism with abundant sorption sites available on the surface and the initial concentration of carbofuran is low compared to the sorption capacities of the CABC. The mass transfer mechanism was studied. The optimization of parameters with central composite design in response surface methodology showed an optimum adsorption uptake value obtained is 134.84 mg⁄g with a desirability value 0.98 with initial concentration as the most influencing parameter.

Sorption of 14C-carbofuran in Austrian soils: evaluation of fate and transport of carbofuran in temperate regions

Carbofuran is an anticholinesterase carbamate commonly used as an insecticide, nematicide and acaricide in agricultural practice throughout the world. However, data on its sorption in temperate soils from Europe is limited. Laboratory studies were conducted to determine the adsorption of carbofuran on three distinct Austrian soils using batch experiments and radiometric techniques. Carbofuran adsorption capacity of the soils was found to be low in the three soils tested and showed to be related to the soils clay and organic carbon contents. The pesticide presented linear adsorption isotherms in all of the three soils. Due to the low sorption of carbofuran in the soils tested and to its high water solubility, there is a risk of migration to water bodies through run off and consequent negative effects on aquatic organisms and soil biota.

Coating polystyrene beads with iron oxide for the adsorption of carbofuran from the water supply

ABSTRACTPopulation growth requires more food production and as a consequence, there is the indiscriminate use of agrochemicals, among them major group are carbamates. At times, runoff of pesticides leads to surface water pollution that serves as a source of public supply. Thus, the presence of these microcontaminants in surface water has become increasingly frequent. The treatment developed in this work uses the principle of adsorption as a technology for the removal of carbamates, more specifically carbofuran. Two methods of coating the polystyrene beads with iron oxide were used to adsorb these microcontaminants from the water. The coating was evaluated through the chemical extraction of iron, analysis by scanning electron microscopy and BET analysis. The metallurgy that presented the best coating was the one that used the ferric chloride. The beads coated by this methodology were used for adsorption tests of carbofuran and showed positive results after verification of the influence of pH on the adsorption process.

Insights into aqueous carbofuran removal by modified and non-modified rice husk biochars.

Biochar has been considered as a potential sorbent for removal of frequently detected pesticides in water. In the present study, modified and non-modified rice husk biochars were used for aqueous carbofuran removal. Rice husk biochars were produced at 300, 500, and 700°C in slow pyrolysis and further exposed to steam activation. Biochars were physicochemically characterized using proximate, ultimate, FTIR methods and used to examine equilibrium and dynamic adsorption of carbofuran. Increasing pyrolysis temperature led to a decrease of biochar yield and increase of porosity, surface area, and adsorption capacities which were further enhanced by steam activation. Carbofuran adsorption was pH-dependant, and the maximum (161mgg-1) occurred in the vicinity of pH5, on steam-activated biochar produced at 700°C. Freundlich model best fitted the sorption equilibrium data. Both chemisorption and physisorption interactions on heterogeneous adsorbent surface may involve in carbofuran adsorption. Langmuir kinetics could be applied to describe carbofuran adsorption in a fixed bed. A higher carbofuran volume was treated in a column bed by a steam-activated biochar versus non-activated biochars. Overall, steam-activated rice husk biochar can be highlighted as a promising low-cost sustainable material for aqueous carbofuran removal.

An efficient p-tetranitrocalix[4]arene based adsorbent for the removal of carbofuran from aqueous media

Present study describes the adsorption of carbofuran (CF) from aqueous solutions using p-tetranitrocalix[4]arene based modified silica through batch and column methods. Various parameters were optimized including initial pesticide concentrations (5 mg L−1), pH (2–10), contact time (60 min) and adsorbent dosage (30 mg). Modified silica was characterized by FT-IR and scanning electron microscope. The adsorption was further explained by Langmuir, Freundlich and Dubinin–Radushkevich (D–R) models. Moreover, adsorption kinetics and adsorption thermodynamics were also investigated. Adsorption in dynamic mode was evaluated by breakthrough volumes and the Thomas model, applying batch conditions using 30 mg of modified silica at pH 5. It has been noticed that CF removal efficiency of modified silica was 98 % as compared to bare silica (48 %). Adsorption of CF on modified silica was found to be multilayer and physical in nature. Consequently, adsorption obeys pseudo-second-order kinetic equation following external mass transfer diffusion process as the rate-limiting step. Thermodynamic parameter (ΔG, ΔS, ΔH) values suggest that the adsorption of CF is spontaneous and exothermic in nature. Thomas model rate constant kTH (cm3 mg−1 min−1) and maximum solid phase concentration (qo mg g−1) was found to be 0.52 and 12.3, respectively, in dynamic mode.

Removal of carbofuran from aqueous solution by orange peel

In this paper, orange peel was utilized as low-cost adsorbent to remove carbofuran from aqueous solution by adsorption. All the experiments were conducted at 30°C to investigate the effects of initial concentration, adsorbent dosage, contact time, ionic strength, and pH on carbofuran adsorption. The results showed that it was effective to remove carbofuran in the alkalic medium and the equilibrium adsorption was practically achieved in 60 min. The presence of NaCl inhibited the adsorption of carbofuran onto orange peel. Langmuir model provided the better correlation of the experimental data and could interpret the adsorption process and the maximum monolayer adsorption capacity was found to be 84.49 mg/g at the temperature of 30°C. The pseudo-second-order kinetic model could describe the adsorption kinetics rationally and the rate-limiting step was the intraparticle diffusion process. It was implied that orange peel may be suitable as adsorbent material for adsorption of N-methyl carbamate insecticides from aqueous solution.

Comparison of batch, stirred flow chamber, and column experiments to study adsorption, desorption and transport of carbofuran within two acidic soils

Different methods (batch, column and stirred flow chamber experiments) used for adsorption and desorption of carbofuran studies were compared. All tested methods showed that the carbofuran adsorption was higher in the soil with the higher organic matter content, whereas the opposite behaviour was observed for the percentage of carbofuran desorbed. However, different methods have revealed some discrepancies in carbofuran adsorption/desorption kinetics. Although batch method showed interesting data on equilibrium experiments, such as a low heterogeneity for the carbofuran adsorption sites independent of soil organic matter content, it had some disadvantages for carbofuran adsorption/desorption kinetic studies. The disadvantages were related with the excessive limitations of this method on kinetics, i.e., no difference could be detected between different soils. However, with column and stirred flow chamber methods the carbofuran adsorption/desorption kinetics of different soils could be compared. Moreover, the absolute values of carbofuran adsorption/desorption and its rate were higher in the stirred flow chamber than in the batch and column experiments. Using stirred flow chamber experiments the carbofuran desorption was significantly faster than its adsorption, whereas carbofuran using column experiments they were similar. These discrepancies should be considered when the results obtained only with one method is discussed.

Effect of CPC, Brij-35, and SDBS Surfactants on the Adsorption and Movement of Carbofuran in Indian Soils

Laboratory studies were conducted to determine adsorption and movement of carbofuran in aqueous surfactant-free and surfactant [(cationic, cetyl pyridinium chloride (CPC), non-ionic, polyoxyethylene lauryl ether (Brij-35) and anionic, sodium dodecyl benezene sulphonate (SDBS)] solutions of different critical micellar concentrations (1/2 × CMC, 1.0 × CMC, and 2 × CMC) in four different Indian soils using batch shake and soil thin layer chromatography (soil TLC) techniques. The measured equilibrium adsorption isotherms were in agreement with the Freundlich equation. Higher adsorption of carbofuran in both systems was observed on FRI silt loam (FSL) soil followed by Alampur silt loam (ASL), Kalai loam (KL), and Bhoran sandy loam (BSL) soils, as anticipated from Freundlich constant KF and distribution coefficient KD, in surfactant-free systems and KF* and KD* in surfactant-soil-water systems. The adsorption of carbofuran in surfactant-soil-water systems followed the order cationic > anionic > non-ionic at all CMCs studied. The Rf values obtained from soil TLC studies confirmed the above order of adsorption. The KD and KD* values were used to evaluate remediation efficiency (KD*/KD) of surfactants. Non-ionic surfactant, Brij-35, and anionic surfactant, SDBS, are favorable for remediating soil contaminated with carbofuran as KD*/KD ratio is less than 1.

Effects of β-cyclodextrin on adsorption and desorption of carbofuran in soils of divergent texture

Laboratory studies were conducted to determine the adsorption/desorption equilibrium of carbofuran between four divergently textured soils and distilled water and an aqueous solution of 0.01 mol L−1 β-cyclodextrin using a batch equilibrium technique. The determined adsorption isotherms for silt loam soils were of L-shaped, for sandy loam soil S-shaped, in agreement with a Freundlich isotherm. In the presence of β-cyclodextrin, the adsorption of carbofuran to the four soils was lower than with distilled water. Positive hysteresis was observed in all soils with distilled water, negative hysteresis when using a solution of β-cyclodextrin as desorbent. The results indicate the potential use of β-cyclodextrin for remediation of pesticide-contaminated soils.

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.

Adsorption and desorption kinetics of carbofuran in acid soils

Carbofuran adsorption and desorption were investigated in batch and stirred flow chamber (SFC) tests. The carbofuran adsorption capacity of the soils was found to be low and strongly dependent on their clay and organic carbon contents. Carbofuran sorption was due mainly (>80%) to fast adsorption processes governed by intraparticle diffusion. The adsorption kinetic constant for the pesticide ranged from 0.047 to 0.195 min −1 and was highly correlated with constant n in the Freundlich equation ( r = 0.965, P < 0.05). Batch tests showed carbofuran desorption to be highly variable and negatively correlated with eCEC and the clay content. The SFC tests showed that soil organic carbon (C) plays a key role in the irreversibility of carbofuran adsorption. Carbofuran desorption increased rapidly at C contents below 4%. The desorption kinetic constant for the compound (0.086–0.195 min −1) was generally higher than its adsorption kinetic constant; therefore, carbofuran is more rapidly desorbed than it is adsorbed in soil.

Adsorption and Movement of Carbofuran in Four Different Soils Varying in Physical and Chemical Properties

Laboratory studies were conducted to determine the adsorption and movement of carbofuran on four divergent textured Indian soils at a fixed volume fraction (fs = 0.1) of methanol/water mixtures using batch equilibrium and soil thin layer chromatography (soil TLC) techniques. The measured equilibrium adsorption isotherms for silt loam (FSL and ASL) and loam (KL) soils were L-shaped and for sandy loam (BSL) soil S-shaped, all being well fitted by the Freundlich isotherm. A higher adsorption of carbofuran was observed on FSL followed by ASL, KL and BSL soils as anticipated by the values obtained for the Freundlich constant, KF and partition coefficient, KD. The Frontal Retardation factor (FRf) values obtained from soil TLC studies were inversely proportional to the KF and KD values. The affinity of carbofuran towards organic carbon, organic matter and clay content of the soils was evaluated by calculating the KOC, KOM and KC values. The negative magnitude of the Gibbs'free energy (ΔG0) indicated the spontaneity of the adsorption of carbofuran onto the soils studied. The leaching index (LI) of carbofuran calculated for the soils studied indicated its high potential to leach into shallow aquifers and ground water. Pearson's correlations calculated for KF and KD against the soil properties showed a highly significant correlation with the clay + silt content of the soils. Multiple regression of KF and KD against the soil properties indicated that the mineral content of the soils (clay and clay + silt) is the best predictor of carbofuran adsorption, followed by soil pH. Predicted log KOM values were also evaluated by using the aqueous solubility, the 1-octanol/ water partition coefficient (KOW), the adsorbability index (AI) and the first-order molecular connectivity index (1χ) of carbofuran. Use of the aqueous solubility, and the 1-octanol/water partition coefficient (KOW) to predict the extent of adsorption gave values which displayed a considerable error in comparison to those measured experimentally, whereas the use of the adsorbability index (AI) and the first-order molecular connectivity index (1χ) of carbofuran improved the predictions considerably.

The usefulness of total concentrations and pore water concentrations of pesticides in soil as metrics for the assessment of ecotoxicological effects ‐ Scientific Opinion of the Panel on Plant Protection Products and their Residues (PPR)

The usefulness of total concentrations and pore water concentrations of pesticides in soil as metrics for the assessment of ecotoxicological effects ‐ Scientific Opinion of the Panel on Plant Protection Products and their Residues (PPR)

Adsorption and desorption characteristics of lindane, carbofuran and methyl parathion on various Indian soils

Adsorption and desorption characteristics of three insecticides on four Indian soils were studied. Insecticides used were representative of organochlorine, organophosphate, and carbomate groups. The order of adsorption of pesticides on soils was: lindane > methyl parathion > carbofuran. Compost soil had shown the maximum adsorption capacity. The order of adsorption capacity of various soils were: compost soil > clayey soil > red soil > sandy soil. Adsorption isotherms were better fitted to Freundlich model and K f values increased with increase in organic matter content of the soils. Thermodynamic parameters indicated favorable adsorption of all the three pesticides in four different soils. Adsorption was exothermic in nature. Distilled water desorbed 30–60% of adsorbed pesticides whereas; organic solvents were able to affect 50–80% of sorbed pesticides. Clay content and organic matter played a significant role in pesticide adsorption and desorption processes. Hysteresis effect was observed in red, clayey and compost soils. Hysteresis effect increased with increase in organic matter and clay content of the soils.

Adsorption-desorption of carbofuran in soils

The results of these studies showed that adsorption of carbofuran on Fe-, Mn- and Cu-saturated soils increased upto the pH 6 and thereafter decreased. The values of 1/n which reflects the curvature in the adsorption isotherms were more than unity Indicating a 'S' type of isotherm. Adsorption followed the order : black > red > alluvial soil. The order of adsorption in presence of different transitionl metals was: Fe- > Mn- > Cu-. The adsorption varied directly with the effective ionic radii of exchangeable cations and inversely with increase in temperature. With the addition of sewage-sludge adsorption also increased. The enthalpy change (ΔH o ) denoted that the process was exothermic and adsorption of carbofuran gave rise to entropy loss. Various studies i.e. IR, thermodynamic parameters and Freundlich adsorption isotherms revealed the existence of co-ordination between exchangeable cation of soil and oxygen of >C=O group of carbofuran.