Applying carbon materials derived from cellulose for the removal of malathion and chlorpyrifos in food processing

The growing use of pesticides to enhance food production leads to their presence in food samples, necessitating the creation of efficient methods for their elimination. This study demonstrates that activated carbon materials derived from cellulose can effectively remove malathion and chlorpyrifos from liquid samples, even when found in complex matrices. Adsorbents were carbonized at 850 °C and activated in the temperature range between 670 and 870 °C where activation time was from 30 to 180 min and CO2 flow rate from 10 to 80 L h −1). After that, materials were characterized in terms of physical and chemical properties using SEM, EDX, BET, FTIR, Raman, and Zeta potential. The synthesized materials were tested by removing malathion and chlorpyrifos from lemon juice and mint ethanol extracts. The results showed that these materials remove these pesticides to a high degree. Furthermore, some of the developed adsorbents exhibit the ability to selectively remove chlorpyrifos in the presence of malathion. These selected materials remain unaffected by the intricate compositions of real samples. Additionally, the adsorbent can be regenerated at least five times without significant performance degradation. Our findings propose that the adsorptive elimination of contaminants from food can substantially enhance food safety and qualityTwenty-First Young Researchers’ Conference - Materials Science and Engineering: Program and the Book of Abstracts; November 29 – December 1, 2023, Belgrade, Serbi

Application of organothiophosphate pesticides oxidation in methods for their detection based on acetylcholinesterase inhibition

Ispitana je inhibicija slobodne acetilholinesteraze (AChE) odabranim organotiofosfatima (OP) (diazinon, malation, hlorpirifos, azinfos-metil, forat) i njihovim oksoanalozima (diazokson, malaokson, hlorpirifos-okson, azinfos-metil-okson, forat-okson), pri čemu su optimizovani uslovi za detekciju najniže koncentracije tih jedinjenja primenom AChE testa. Određene su IC50 vrednosti za sva navedena jedinjenja. U cilju povećanja osetljivosti AChE testa, ispitivani organo-tiofosfati prevedeni su u okso-analoge u prisustvu enzima mijeloperoksidaze (MPO). To je potvreno pomoću UPLC i GC/MS analize. Nastali oksidacioni proizvodi stabilni su najmanje 1h. Maksimalne koncentracije oksona dobijaju se kada se organo-tiofosfati inkubiraju sa 100 nM MPO u prisustvu H2O2 koncentracije 50 μM, pri pH 6, na temperaturi 25 °C u toku 10 minuta. Oksidacija OP u prisustvu MPO pod navedenim uslovima primenjena je u modifikaciji metode za detekciju OP na bazi inhibicije AChE. Određena je granica detekcije modifikovane metode, kao i efikasnost oksidacije i njena primena na smešu OP. Gore navedeni organo-tiofosfati prevedeni su u odgovarajue oksone i pomoću elektrohemijski generisanih halogena. Proizvodi koji nastaju identifikovani su kao oksoni pomoću UPLC analize. Utvrđeno je da je najefikasnija oksidacija elektrogenerisanim bromom u toku 15 minuta. Određena je i granica detekcije AChE testa za odreivanje OP kada su OP oksidovani elektrohemijski generisanim bromom...The inhibition of acetylcholinesterase in the presence of selected organothiophosphates (diazinon, malathion, chlorpyrifos, azinphos-methyl, phorate) and their oxo-analogues (diazoxon, malaoxon, chlorpyrifos-oxon, azinphos-methyl-oxon, phorate-oxon) was examined. Experimental conditions were optimized to detect the lowest posible concentrations of these compounds using AChE test. IC50 values were determined for all the mentioned compounds. Investigated organothiophosphates have been converted into their oxo-analogues in the presence of the enzyme myeloperoxidase. Oxidation products were detected using UPLC and GC/MS analysis. It was found that the products are stable within minimum 1h. In order to optimize oxidation procedure and achieve maximum concentrations of oxons, the optimal concentrations of H2O2 (50 μM) and MPO (100 nM) were determined. Also, the optimal incubation time of OPs and MPO (10 min), as well as the optimal pH (6) and temperature (25 °C) were estimated. Oxidation of OPs in the presence of MPO under optimal conditions was applied as a modification of the method for detecting OP using AChE test. The detection limits were determined for the modified method, as well as the efficiency of oxidation and its application for the analysi of sintetic mixture of OPs. Examined organothiophosphates have been converted into their oxo-forms using electrochemically generated halogens. Products have been identified as oxons using UPLC analysis. It was found that the the most efficient oxidation of OPs was carried out by after 15 minutes of oxidation with electrogenerated bromine. Detection limits were determined, too

The impact of thermal treatment on spent coffee grounds for chlorpyrifos removal from water

Coffee is one of the world's most beloved beverages, with an annual production exceeding 10.5 million tons. However, the extensive generation of spent coffee grounds (SCGs) raises environmental concerns when carelessly disposed of. Also, the growing issue of pesticide contamination in water and food poses an environmental challenge. Given the hazardous nature of pesticides and their potential to inflict severe health consequences, it is important to understand how these compounds interact with biowaste materials. In this study, the spent coffee grounds are thermally treated at 400, 650, and 900 °C and named C400, C650, and C900, respectively. The synthesized materials and the initial SCG have been characterized using SEM, EDX, and FTIR. The kinetics of chlorpyrifos (CHP) adsorption on these materials has been investigated using pseudo-first-order (PFO), pseudo-second-order (PSO), Elovich, and intraparticle diffusion kinetic models. Adsorption experiments were done at three temperatures (25, 30, and 35°C), and the obtained experimental results were analyzed using non-linear Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich isotherm models. Thermodynamics of the process has also been investigated. The results showed that the CHP adsorption process on all four materials fits equally well in both PFO and PSO and that the equilibrium time is 400 min. Isotherm study of adsorption on all three temperatures shows very good fitting in both Freundlich and Langmuir isotherm models. Langmuir isotherm model revealed that the maximum concentration of CHP that can be adsorbed by 1g of materials (qmax) is 2.31 mg g-1 , 19.43 mg g-1 , 4.67 mg g-1 , and 10.98 mg g-1 for SCG, C400, C650, and C900 respectfully. Thermodynamic parameters revealed that the adsorption of CHP on all investigated materials is a spontaneous process. By increasing the adsorption temperature, the qmax value increases for SCG, C650, and C900, indicating that the process is exothermic, and decreases in the case of C400, indicating that the process is endothermic.Twenty-First Young Researchers’ Conference - Materials Science and Engineering: Program and the Book of Abstracts; November 29 – December 1, 2023, Belgrade, Serbi

Removal of chlorpyrifos and malathion using spent coffee grounds – isotherm study

In recent years, the extensive use of chlorpyrifos (CHP) and malathion (MLT), two common organophosphate (OP) insecticides, has raised concerns about their adverse effects on the environment and human health [1]. These pesticides can contaminate water bodies, soil, and food, posing potential risks to non-target organisms and human populations [2, 3]. Therefore, there is a growing demand for effective and sustainable methods to remove these pesticides from the environment [4]. Spent coffee grounds (SCG), a readily available agricultural waste, have shown promising potential as an adsorbent [3]. The aim of this study was to investigate the removal of CHP and MLT using SCG as an adsorbent and to examine the adsorption behavior through isotherm analysis. Isotherm analysis was performed using four isotherm models: Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich. The experimental data best fit the Langmuir isotherm model, suggesting a monolayer adsorption process on homogeneous adsorption sites. According to the Langmuir isotherm, the maximum adsorption capacity of SCG for CHP and MLT is 2.34 mg/g and 7.04 mg/g, respectively. Additionally, the Freundlich isotherm model fitted the experimental data for MLT adsorption on SCG very well, implying multilayer physisorption even after all adsorption sites are occupied. These findings provide valuable insights into the feasibility of SCG as an eco-friendly approach for the removal of CHP and MLT from the environment. The energy of adsorption obtained from the DubininRadushkevich isotherm confirmed that in the case of CHP adsorption the binding is stronger than in the case of MLT adsorption.INTERNATIONAL Student Conference on Technical Science; October 20-21, Bor Lak

Activated porous carbon materials derived from viscose fibers for chlorpyrifos removal from water

The extensive use of the toxic organophosphate chlorpyrifos underscores the need for effective methods to eliminate it from the environment [1]. Chlorpyrifos's acute neurotoxicity stems from its irreversible inhibition of acetylcholinesterase, an enzyme crucial for signal transmission in the nervous system. This inhibition can lead to various neurological disorders [1,2]. While several methods have been explored for removing chlorpyrifos from water, adsorption is one of the most promising approaches [3]. Viscose fibers derived from cellulose are frequently investigated as a potential source for producing activated carbon materials [1]. Our study employed carbon materials derived from viscose fibers as an adsorbent for chlorpyrifos. Our findings revealed that 1 gram of these carbon materials could adsorb 171.53 mg, 169.20 mg, and 175.44 mg of chlorpyrifos at a temperature of 25°C. We also delved into the kinetics of batch adsorption to remove chlorpyrifos from water solutions. Kinetics analysis was performed using pseudo-first-order, pseudo-second-order, and Elovich kinetic models. The results indicated that the adsorption of chlorpyrifos onto the carbon materials best followed the pseudo-second-order kinetics model under the specified experimental conditions. The constant rate values were determined to be 0.217 mg g-1 min-1 , 0.076 mg g-1 min-1 , and 0.491 mg g-1 min-1 under experimental conditions.INTERNATIONAL Student Conference on Technical Science; October 20-21, Bor Lak

Cellulose-derived carbon materials: A study of isotherms in malathion removal

Pesticides, whether synthetic or natural, are crucial in managing insects, and weeds, and influencing plant growth. However, the widespread use of organophosphates, a highly effective class of chemical pesticides, raises environmental concerns due to their slow biodegradation, resulting in ecosystem and food chain contamination. The inhibitory effect of organophosphates on acetylcholinesterase contributes to various health disorders. Malathion, commonly used for mosquito and insect control in crops and pet care, exhibits gradual decomposition in water and soil, leading to heightened concentrations in discharge areas and potential risks to aquatic organisms and human health. To address the removal of organophosphates, various methods have been explored, with adsorption standing out for its simplicity, cost-effectiveness, and environmental friendliness. Cellulose-derived carbon materials, characterised by porous structures and large surface areas, provide an efficient solution. This study focuses on utilising cellulose-derived carbon materials as an adsorbent for malathion removal, employing SEM, EDX, FTIR, and BET analysis for comprehensive characterisation. The investigation concentrates on malathion adsorption onto cellulose-derived carbon materials, employing four isotherm models: Freundlich, Langmuir, Temkin, and DubininRadushkevich. The experimental data best fit the Freundlich isotherm, indicating a multilayer adsorption mechanism on the heterogeneous surface of carbon materials. The Langmuir isotherm model shows the maximum adsorption capacities for malathion onto materials CDCM3, CDCM6, and CDCM8, respectively, are 38.67 mg g-1, 170.20 mg g-1, and 254.41 mg g-1. The adsorption energy from the Dubinin-Radushkevich isotherm confirms that the adsorption process for malathion removal is physisorption, while the Temkin isotherm suggests an exothermic process. These findings significantly contribute to sustainable strategies for mitigating the environmental impact of organophosphates.Third DIFENEW International Student Conference : 5th December 2023, Novi Sad

Highly Porous Cellulose-Based Carbon Fibers as Effective Adsorbents for Chlorpyrifos Removal: Insights and Applications

The extensive utilization of the organophosphate pesticide chlorpyrifos, combined with its acute neurotoxicity, necessitates the development of effective strategies for its environmental removal. While numerous methods have been explored for chlorpyrifos removal from water, adsorption is the most promising. We investigated the potential of two cellulose-derived porous carbons as adsorbents for chlorpyrifos removal from water, prepared by either CO2 or H2O activation, resulting in similar morphologies and porosities but different amounts of heteroatom functionalities. The kinetics of batch adsorption removal from water fits well with the pseudo-first-order and pseudo-second-order kinetic models for both materials. The Freundlich, Langmuir, Dubinin–Radushkevich, and Sips isotherm models described the process of chlorpyrifos adsorption very well in all investigated cases. The maximum adsorption capacity determined from the Sips isotherm model gave values of 80.8 ± 0.1 mg g−1 and 132 ± 3 mg g−1 for the H2O and CO2 activated samples, respectively, reflecting the samples’ differences in heteroatom functionalities. Additionally, the application of either adsorbent led to reduced toxicity levels in all tested samples, implying that no harmful byproducts were generated during adsorption. Comparative analysis with the existing literature further validates the study’s findings, suggesting the efficacy and applicability of cellulose-based porous carbons for sustainable chlorpyrifos remediation

Structural properties of graphene-oxide and its capacity for the elimination of dimethoate from water

Organophosphate pesticides are known to be some of the most toxic substances synthesized by a man today. Extensive use of this group of compounds in contemporary agriculture results in a critical need for their efficient removal from the environment, especially water. Adsorption of pesticides on different materials is one of the most frequently used strategies for this purpose. In the past decade, the use of graphene-oxide escalated due to its interesting properties. In this contribution, the adsorption of organophosphate pesticide dimethoate on two commercially available graphene-oxides has been investigated. The materials were characterized by different physico-chemical methods. Careful structural characterization of adsorbents was combined with batch adsorption experiments. It was shown that 1 g of both graphene-oxides is capable of adsorbing 9×10-3 mol dm-3 of dimethoate at 25 °C. A satisfactory agreement of both sets of experimental results with the Langmuir isotherm model suggests the monolayer adsorption on the homogenous surface. The adsorption was also investigated at 30 and 35 °C. The results showed that the concentration of adsorbed dimethoate increases with temperature for both studied adsorbents. Investigated grapheneoxides were successfully used for the removal of dimethoate from water.X Serbian Ceramic Society Conference - Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts; September 26-27, 2022; Belgrad

Effect of temperature for chlorpyrifos adsorption onto carbon material derived from spent coffee grounds

Pesticides are extensively used in agriculture to enhance crop yield and combat pests and pose a significant threat to ecosystems and human health when their residues accumulate in soil and water. Conventional methods of pesticide removal are often costly or introduce secondary pollutants. The increasing worry about pesticides harming the environment has led to more research on their removal. Various biowaste materials have been investigated for remediation of these contaminants. Among investigated materials, spent coffee grounds, a widely available waste product, offer a promising solution. Coffee consumption is a daily ritual, generating substantial quantities of spent coffee grounds as residual waste. Harnessing the adsorption potential of spent coffee grounds for pesticide removal addresses an environmental challenge and aligns with waste management principles and a circular economy. The carbon material, obtained through a controlled carbonisation process of spent coffee grounds at 900 ºC, showed high adsorption potential for chlorpyrifos. The Langmuir and Freundlich models were employed to analyse the adsorption process, revealing favourable adsorption behaviour at different temperatures. Thermodynamic parameters indicated the spontaneous and feasible nature of the adsorption process, with temperature being an important factor for the adsorption of chlorpyrifos on the investigated material.Third DIFENEW International Student Conference : 5th December 2023, Novi Sad

Biowaste-Based Carbon Material for Malathion Removal from Water

The extensive application of a pesticide, such as malathion, is a potential risk to human health as it can easily enter the food chain. An efficient and economical method for pesticide removal from the environment is necessary. In this work, we prepared a carbon material derived from biowaste (rabbit litter) for the removal of malathion from water. The adsorption capacity of carbon material derived from used litter (UL) is higher than that made from not-used litter. The maximum adsorption capacity of UL is 1.16 x10-5 mol/g for malathion