Glyphosate Removal Research Articles

Synthesis of highly porous ferric hydroxide-bacterial cellulose nanocomposites via in-situ mineralization for efficient glyphosate removal

Synthesis of highly porous ferric hydroxide-bacterial cellulose nanocomposites via in-situ mineralization for efficient glyphosate removal

Optimizing Glyphosate Removal from Water Using a Peracetic Acid-Assisted Advanced Oxidation Process: A Response Surface Methodology Approach

Glyphosate (GLY), one of the most used pesticides in the world, has been frequently detected in water, posing chronic and remote hazards to human health and the environment. Consequently, it has become necessary to develop efficient and sustainable treatment processes able to remove GLY from the polluted aquatic environments. In this context, the use of advanced oxidation processes is of great interest, as it allows for a significant reduction in concentrations of recalcitrant pollutants. In this study, peracetic acid (PAA) was used for the first time to remove GLY from water. In particular, the process parameters (oxidant dose, activation by UV radiation, GLY concentration, process time) were optimized using central composite design (CCD) and response surface methodology (RSM). The degradation of the pollutant, i.e., GLY, was monitored by ion chromatography, optimizing the instrumental parameters. During the process, residual oxidant concentrations were also constantly monitored using reference methods (i.e., UV-visible spectroscopy). Based on the results obtained, the best GLY removals (over 90%) were achieved under the following conditions: a PAA/GLY molar ratio of 3 (concentration of 3.0 mg/L for GLY and 4.0 mg/L for PAA), UV irradiation, and a process time of 45 min. The possibility of achieving total glyphosate removal by using small amounts of oxidant increases the environmental sustainability of the proposed aquatic pollution mitigation strategy.

Removal of Glyphosate with Nanocellulose for Decontamination Purposes in Aquatic Systems

Removal of Glyphosate with Nanocellulose for Decontamination Purposes in Aquatic Systems

Adsorption of Glyphosate in Water Using Iron-Based Water Treatment Residuals Derived from Drinking Water Treatment Plants

Glyphosate, a broad-spectrum herbicide, poses a potential threat to human health and the ecosystem due to its toxicity. In this study, iron-based water treatment residuals (Fe-WTRs) were employed for glyphosate removal. The adsorption kinetics, isotherms, and thermodynamics, as well as the effects of pH, Fe-WTR particle size, and temperature, were explored. The results show that Fe-WTRs are an effective adsorbent for glyphosate adsorption, and the maximum uptake capacity was recorded as 30.25 mg/g. The Fe-WTR surface was positively charged, and low-valent iron dominated under acidic conditions, favoring glyphosate adsorption. Furthermore, smaller Fe-WTR particles (<0.125 mm) showed a faster absorption rate and 20% higher adsorption capacity than larger particles (2–5 mm). The kinetic analysis indicated that the adsorption process exhibits a two-step profile, conforming to the pseudo-second-order model, and the thermodynamic analysis indicated that it is a spontaneous, endothermic, and entropy-driven reaction. Finally, the Fourier transform infrared spectral analysis revealed that this process is mainly associated with the formation of metal phosphate through the ligand exchange of the phosphate groups of glyphosates with the hydroxyl groups of iron present in Fe-WTRs. In this study, we demonstrated the potential of Fe-WTRs as a cost-effective and efficient adsorbent for glyphosate removal.

Comparing the abiotic removal of glyphosate by β-MnO2 and δ-MnO2 colloids: Insights into kinetics and mechanisms

Glyphosate as an effective broad-spectrum herbicide is frequently detected in various water and soil resources. Given the ubiquity of β-MnO2 and δ-MnO2 colloids in groundwater and soil, the abiotic removal of glyphosate by MnO2 colloids was investigated. β-MnO2 colloids exhibited superior glyphosate removal efficiency, up to 37%, compared to 21% for δ-MnO2 colloids at a pH of 4.0. Glyphosate removal involved simultaneous adsorption and oxidation process, identified by HRTEM, NH3-TPD, XPS, LC-MS, FTIR analyses and the occurrence of aminomethylphosphonic acid (AMPA) and Mn2+. Moreover, adsorption dominated the removal of glyphosate by two MnO2 colloids. The solution pH had a substantial effect on glyphosate removal. Co-existing ions in the solution, such as carbonate (CO32−), phosphate (Na2HPO4, NaH2PO4) and humic acid (HA), were also found to impede glyphosate removal. Phosphate, in particular, exhibited a strong competitive effect for adsorption sites on both MnO2 colloids. Of them, the removal of glyphosate by β-MnO2 colloids was more prone to occur due to its higher specific surface area, abundant oxygen vacancies, and moderate acid sites. However, δ-MnO2 colloids presented a stronger oxidation capacity than that of β-MnO2 colloids due to the quicker generation rate of Mn2+. Finally, AMPA was the same products by two MnO2 colloids in the oxidation process, revealing the degradation pathway based on the cleavage of C–N bond. Therefore, by comparing kinetics and mechanisms of glyphosate removal by β- and δ-MnO2 colloids, this study improves us better understanding for the behavior of glyphosate in the environment.

Revealing the vital role of dissolved O2 in Cu(II)-Cu(I)-Cu(III) cycle for promoting glyphosate degradation via percarbonate activation

High-valent copper (Cu(III)) is a potential active species for the degradation of organic pollutants among the Fenton-like reactions. Cu(I), as the key intermediate for the generation of Cu (III), is often affected by the low reaction rate between Cu(II) and oxidants. Herein, glyphosate, as an universal herbicide, was efficiently eliminated by percarbonate (SPC) via addition of trace Cu(II) (50 μM). Batch experiments results showed that 97.6 % of glyphosate (0.10 mM) was degraded into orthophosphate (PO43-) by Cu(II)/SPC within 30 min over a wide pH scope (4 ∼ 10). Scavenging experiments and electron spin resonance (EPR) revealed that Cu(III) was the major active species in glyphosate degradation. The removal efficiency of glyphosate might be influenced by the phosphorus species under different pH conditions. Moreover, during the removal process of glyphosate, the in-situ generation of oxygen (O2) in Cu(II)/SPC system could be converted into superoxide radical (·O2–), which exhibited higher reaction rate with Cu(II) to produce Cu(I), and further transformed into Cu(III) for the removal of glyphosate. Overall, this work successfully structured a rapid way to the removal of glyphosate, and effectively alleviated the problem of low concentration of dissolved O2 in water caused by O2 consumption in Fenton reaction via the generation of in-situ O2.

Green synthesis of bimetallic CuO@NiO nanocomposite for the removal of glyphosate

Green synthesis of photocatalyst bimetallic CuO@NiO nanocomposite for eliminating organic hazardous glyphosate (Gly) solution has been introduced. The nanocomposite has been successfully developed from mango (Mangifera indica L.) peel extracted solution by a simultaneous reduction process. HRTEM, XRD, and EDX have also been used to explore the nanostructure, crystal conformation, and chemical compositions of CuO@NiO. Using UV-vis spectrometer, we have observed the photo-catalytic activity and kinetic removal rate constant of CuO@NiO in terms of glyphosate elimination under UV light illumination. Compared with pure CuO and NiO nanoparticles, CuO@NiO displayed improved and enhanced photocatalytic activity. This work demonstrates an eco-friendly, low-cost material with high efficiency for removing Gly, which has applications in environmental protection.

Nanosized lanthanum peroxide–loaded biochar composites for simple and effective glyphosate removal from wastewater: Behavior and mechanisms

The extensive use of glyphosate-based herbicides and its high solubility in water have led to its accumulation in aquatic environments, posing a risk to the ecological environment and human health. Therefore, an effective method for removing glyphosate from wastewater is urgently needed. Herein, a novel nanosized lanthanum peroxide–loaded biochar composite (n-LBC) was prepared using a simple precipitation method, in which biochar served as a dispersant and catalyst to improve the oxidation ability of nanosized lanthanum peroxide. Compared with other common metal peroxide systems, n-LBC exhibited better oxidation ability and achieved a glyphosate removal efficiency of 99.6%. Moreover, n-LBC retained the self-buffering effect of lanthanum peroxide and thus remained effective over a wide pH range, overcoming the problem of pH elevation observed in other metal peroxide systems. The mechanism for glyphosate removal was found to be a combined process of electrostatic attraction, oxidation, and inner-sphere complex formation. Most glyphosate could be oxidized to H2PO 4− by breaking the C–N bonds, and H2PO4− could be attracted to the material surface simultaneously by electrostatic attraction, forming La–O–P inner-sphere complexes. Thus, n-LBC is a simple and highly effective material for glyphosate removal.

Modification of bio-zeolite greenly synthesized from rice husk and application in adsorptive removal of herbicide glyphosate

In this study, the bio-zeolite (BZ) was successfully fabricated by solvothermal method from the rice husk. The fabricated BZ was thoroughly characterized by SEM, XRD, XRF, BET, and FT-IR. The BZ characteristics were demonstrated with a homogenous, porous, and crystal structure, a uniform round edge shape, a SiO2/Al2O3 ratio of about 2.65, a specific surface area of 3.31 m2 g−1, and specific linkages of Si–O–Al, Si–O–Si, and Si–OH. Subsequently, the BZ particles were modified by the adsorption of a cationic surfactant CTAB. Then CTAB@BZ was applied as an effective adsorbent to remove the herbicide glyphosate (GP) from aqueous solutions. The GP removal variables were optimized at 10 mM CTAB, pH 5, free ionic strength, 1 mg mL−1 BZ dosage, and 60 min contact time. The GP removal efficiency was more significantly enhanced by greater than 90 % with the surface modification. The GP adsorption isotherm was accorded to the pseudo-second-order model with multiple-adsorbed layer formation. The GP adsorption mechanisms were the main surface adsorption due to the major CTAB-GP electrostatic attractions.

Removal characteristics of high concentration glyphosate in bioretention cells

ABSTRACT Glyphosate, as one of the most widely used pesticides, has been found in rainwater runoff. A bioretention cell with two types of fillers was constructed to explore removal of glyphosate in runoff an transformation of glyphosate in the filler. The type of filler had a significant impact on adsorption and degradation of glyphosate in the bioretention cell. The glyphosate removal efficiencies of coal cinder modified loess (CLB) and zeolite modified loess (ZLB) were 33.13–99.7% and 55.04–99.7%, respectively. Conversion of glyphosate in the bioretention cell occurred mainly in the upper layer of the filler. When the concentration of glyphosate in the runoff was 0.25 or 0.5 mg/L, the concentration of glyphosate degradation products at the two outlets along the way was as much as 26 times higher than that at the lowest outlet. Rainfall events promoted the migration of glyphosate and its degradation products within the filler. Glyphosate and its degradation products in ZLB were mainly distributed at 15 and 25 cm deep in the filler layer, while the highest concentrations in CLB were at 5 and 35 cm. Discontinuous runoff into the bioretention cell leads to continuous leaching and adsorption of glyphosate in the bioretention cell until complete degradation occurs.

Engineering Electrode Polarity for Enhancing In Situ Generation of Hydroxyl Radicals Using Granular Activated Carbon.

Recently, granular activated carbon (GAC) has shown its effectiveness as a cathode material for in situ ROS generation. Here, we present an electrochemically modified GAC cathode using electrode polarity reversal (PR) approach for enhanced H2O2 decomposition via 2-electron oxygen reduction reaction (2e-ORR). The successful GAC modification using PR necessitates tuning of the operational parameters such as frequency, current, and time intervals between the PR cycles. This modification enhances the GAC hydrophilicity by increasing the density of surface oxygen functionalities. After optimization of the electrode polarity, using the 20 (No PR)-2 (PR) interval and 140 mA current intensity, the •OH concentration reaches 38.9 μM compared to the control (No PR) (28.14 μM). Subsequently, we evaluated the enhanced •OH generation for the removal of glyphosate, a persistent pesticide used as a model contaminant. The modified GAC using PR removed 67.6% of glyphosate compared to 40.6% by the unmodified GAC without PR, respectively. The findings from this study will advance the utilization of GAC for in situ ROS synthesis, which will have direct implications on increasing the effectiveness of electrochemical water treatment systems.

The Effect of Silica Nanoparticles Addition on Removal of Glyphosate Residue from Aqueous Solutions

Al-Tharwani, W.S., M.T. Mohammadali and I.M. Abd al-Ridha. 2024. The Effect of Silica Nanoparticles Addition on Removal of Glyphosate Residue from Aqueous Solutions. Arab Journal of Plant Protection, 42(2): 255-259. https://doi.org/10.22268/AJPP-001231 The aim of this study was to evaluate herbicide Tiller 48% SL (Glyphosate) residues in aqueous water by using silica nanoparticles as adsorption agent to remove glyphosate from aqueous solutions. Results obtained showed that when three concentrations of 10, 15 and 20 ml/L water were used, glyphosate concentration determined immediately after treatment was 3520, 5600 and 7955 mg/L, respectively. The concentration of the herbicide decreased with time and reached 1203 mg/L on the tenth day after treatment. No residues were detected by HPLC 21 days after treatment. The results of the study of the use of Nano-silica as an agent for the removal of glyphosate in aqueous solutions showed that the concentration 200 mg/L nano-silica achieved the highest rate of herbicide removal of 89.37%, outperforming the other two concentrations of 100 and 150 mg/L, which achieved 63.45 and 82.87% removal, respectively. Keywords: Glyphosate, residues, silica nanoparticles, adsorptio

Determination of the effect of iron oxide nanoparticle content in magnetic chitosan/calcium alginate hydrogel matrix on the removal of glyphosate from water

Determination of the effect of iron oxide nanoparticle content in magnetic chitosan/calcium alginate hydrogel matrix on the removal of glyphosate from water

Assessment of chitosan-based adsorbents for glyphosate removal

Exposure to glyphosate produces various toxic effects, due to this, different methods have been evaluated for its elimination. The objective of this work was to formulate chitosan-based adsorbents and evaluate their efficiency in the removal of glyphosate in vitro. Four films were made by varying the weight ratio of silica/chitosan particles, and four sponges were made by varying the chitosan/chitosan ratio in a reticulated manner. Both adsorbents were characterized based on their porosity, water absorption, glyphosate removal, and reusability. It was found that increasing the porosity in both films and sponges resulted in an increase in the adsorption efficiency of glyphosate. The adsorption process exhibited a better fit in both adsorbents to the pseudo-second-order model. The adsorption of glyphosate to the films fit better with the Langmuir model, demonstrating that the process occurs in the form of a monolayer. In the case of sponges, the adsorption of glyphosate fit better with the Freundlich model, indicating that the process takes place in a multilayer form. Finally, when the reusability was evaluated, the adsorbents showed a loss of effectiveness. However, they still proved to be an efficient alternative for the removal of glyphosate in water, providing a cost-effective and environmentally friendly solution.

Removal of glyphosate (GLY) and aminomethylphosphonic acid (AMPA) by ultrafiltration with permeate-side polymer-based spherical activated carbon (UF–PBSAC)

Glyphosate (GLY) is the most commonly used herbicide worldwide, and aminomethylphosphonic acid (AMPA) is one of its main metabolites. GLY and AMPA are toxic to humans, and their complex physicochemical properties present challenges in their removal from water. Several technologies have been applied to remove GLY and AMPA such as adsorption, filtration, and degradation with varied efficiencies. In previous works, an ultrafiltration membrane with permeate-side polymer-based spherical activated carbon (UF–PBSAC) showed the feasibility of removing uncharged micropollutants via adsorption in a flow-through configuration. The same UF–PBSAC was investigated for GLY and AMPA adsorption to assess the removal of charged and lower molecular weight micropollutants. The results indicated that both surface area and hydraulic residence time were limiting factors in GLY/AMPA adsorption by UF–PBSAC. The higher external surface of PBSAC with strong affinity for GLY and AMPA showed higher removal in a dynamic process where the hydraulic residence time was short (tens of seconds). Extending hydraulic residence times (hundreds of seconds) resulted in higher GLY/AMPA removal by allowing GLY/AMPA to diffuse into the PBSAC pores and reach more surfaces. Enhancement was achieved by minimising both limiting factors (external surface and hydraulic residence time) with a low flux of 25 L/m2.h, increased PBSAC layer of 6 mm, and small PBSAC particle size of 78 µm. With this configuration, UF–PBSAC could remove 98 % of GLY and 95 % of AMPA from an initial concentration of 1000 ng/L at pH 8.2 ± 0.2 and meet European Union (EU) regulation for herbicides (100 ng/L for individuals and 500 ng/L for total herbicides). The results implied that UF−PBSAC was able to remove charged micropollutants to the required levels and had potential for application in wastewater treatment and water reuse.

Ecotoxicology Evaluation of a Fenton-Type Process Catalyzed with Lamellar Structures Impregnated with Fe or Cu for the Removal of Amoxicillin and Glyphosate.

Antibiotics and pesticides, as well as various emerging contaminants that are present in surface waters, raise significant environmental concerns. Advanced oxidation processes, which are employed to eliminate these substances, have demonstrated remarkable effectiveness. However, during the degradation process, by-products that are not completely mineralized are generated, posing a substantial risk to aquatic ecosystem organisms; therefore, it is crucial to assess effluent ecotoxicity following treatment. This study aimed to assess the toxicity of effluents produced during the removal of amoxicillin and glyphosate with a Fenton-type process using a laminar structure catalyzed with iron (Fe) and copper (Cu). The evaluation included the use of Daphnia magna, Selenastrum capricornutum, and Lactuca sativa, and mutagenicity testing was performed using strains TA98 and TA100 of Salmonella typhimurium. Both treated and untreated effluents exhibited inhibitory effects on root growth in L. sativa, even at low concentrations ranging from 1% to 10% v/v. Similarly, negative impacts on the growth of algal cells of S. capricornutum were observed at concentrations as low as 0.025% v/v, particularly in cases involving amoxicillin-copper (Cu) and glyphosate with copper (Cu) and iron (Fe). Notably, in the case of D. magna, mortality was noticeable even at concentrations of 10% v/v. Additionally, the treatment of amoxicillin with double-layer hydroxides of Fe and Cu resulted in mutagenicity (IM ≥ 2.0), highlighting the necessity to treat the effluent further from the advanced oxidation process to reduce ecological risks.

A bacterial consortium and L-tryptophan boosted glyphosate removal, mungbean growth and physiology in contaminated soil

A bacterial consortium and L-tryptophan boosted glyphosate removal, mungbean growth and physiology in contaminated soil

Experimental and CFD simulation of glyphosate removal by a filter-press electrocoagulation reactor

The present communication proposes a lumped kinetic and phenomenological model for glyphosate removal in synthetic agro-industrial wastewater using an electrocoagulation process (EC). A traditional filter press-cell electrochemical reactor is used for the EC experimental process. The outcomes of the current density, electrode material, and electrolysis process time were analyzed. The experimental results evidence a better removal performance for the aluminum than the carbon steel, and stationary removal conditions were reached at 40 min with a removal efficiency > 40% considering an input flow of 2 L min−1 and operational cost of 0.172 USD m−3 at 7.5 mA cm−2. The XRD analysis evidenced the interaction between the aluminum ion and the pesticide. The residual aluminum in the supernatant was < 10 mg L−1 at stationary removal conditions. The species distribution inside the reactor is described by the theoretical analysis, which takes into account the simultaneous solution of the Reynolds averaged Navier-Stokes (RANS) and kinetic-based mass conservation equation. Under full electrokinetic control (secondary current distribution), the electrode kinetics characterizing the flux generation of Al3+ on the anode is also taken into consideration. The model proposed here can explain the experimental COD removal attributed to the glyphosate concentration as a function of the aluminum dose due to the applied current density. The model is fitted to experimental data to calculate the kinetic and transport parameters.

Biochar as a sustainable alternative for the use of residues from the processing of açaí and the removal of glyphosate

In this study, adsorbents produced from residues from the processing of açaí from the Amazon were acquired and impregnated or not with FeCl2 and FeCl3 to remove glyphosate present in the aqueous matrices. The effects of pH, adsorbent mass, glyphosate concentration, contact time and temperature on the adsorption capacity, kinetics, isothermal and thermodynamic parameters were studied via batch adsorption tests. The removal of glyphosate in the açaí seed biochar with Fe was higher than that in the açaí seed biochar, reaching a removal efficiency of 87.9% when using 20 mg L−1 glyphosate and 10 g L−1 adsorbent. The pH study demonstrated greater adsorption capacities at pH 4.0 (18.6 mg g−1). The pseudo-first-order model was the most appropriate to describe the adsorption kinetics. The Weber-Morris model showed that the adsorption occurred by film and intra-particle diffusion. Adsorption equilibrium isotherms were better fitted to the Langmuir model (qm= 351.4 mg g−1). Thermodynamic data demonstrated that the process was spontaneous and favorable and that the adsorption was exothermic in nature. Because they have magnetic characteristics, açaí seed biochar with Fe can be easily separated and reused. Therefore, depending on the adsorption capacity of the adsorbent with iron and the adsorption efficiencies demonstrated in this study, it is concluded that the adsorbent can be used as an intermediate in the processes of removing glyphosate present in aqueous matrices.

Insights into Glyphosate Adsorption in Aqueous Solutions Using Zn-Al Layered Double Oxide

AbstractContamination of surface and groundwater with glyphosate, used widely on crops to control weeds, can cause severe environmental damage. Processes for glyphosate removal from water bodies have been developed, but few are effective and all are expensive. This objective of the present study was to investigate the use of a layered double oxide as a potentially effective and inexpensive material to remove glyphosate from water. Equilibrium, kinetics, and adsorption mechanisms were evaluated, in addition to the effects of competing anions and temperature on glyphosate adsorption. Up to 95% of glyphosate was removed from a synthetic solution in 50 min by Zn2Al-LDO (layered double oxide in Zn/Al ratio of 2:1) at pH 10. The adsorption isotherms were type L and the Langmuir model best fitted the experimental data, with a qmax value of 191.96 μg mg–1 at 25°C. The XRD pattern did not support the hypothesis of intercalation of glyphosate anions, whereas Fourier-transform infrared and solid-state 13C and 31P magic angle spinning nuclear magnetic resonance confirmed the adsorption of glyphosate anions on the Zn2Al-LDO surface, through carboxylate and phosphonate moiety interactions with end-on and side-on modes. The degree of removal of glyphosate increased with increasing temperature and decreased with increasing concentration of competing anions, with carbonate anions having the most prominent effect on the inhibition of glyphosate adsorption. The adsorption kinetics fitted a pseudo-first order law. Moreover, the intraparticle diffusion model suggested that the adsorption process depends on the formation and thickness of the film at the solution/solid interface.