Pesticide Pollution Research Articles

Terrestrial insect defences in the face of metal toxicity.

Recently, there has been growing concern about the impacts of metal pollutants on insect populations, particularly as human societies increasingly rely on metal-based technologies. Unlike organic pollutants, metals - both essential and non-essential - are non-degradable and readily accumulate in insect tissues, sometimes reaching hazardous levels. While numerous studies address how insects cope with pesticide pollution, there is a notable scarcity of knowledge regarding their abilities to confront metal pollution. This paper reviews the routes of entry for metals into insect cells and the molecular damages they trigger. Additionally, it examines the defence mechanisms insects may employ to counteract metal pollution. Firstly, insects may detect and avoid metals in their environment, thereby escaping contaminated food, substrates, and oviposition sites. Secondly, the insect cuticle and gut lining, including the gut microbiota, may serve as physical barriers preventing metal entry into the hemolymph, thereby protecting other organs. Thirdly, insect cells may detoxify metals by sequestering them in metal-scavenging proteins (e.g., metallothioneins) and excreting them via faeces or the cuticle. Fourthly, when metal-related damage occurs, including oxidative stress, protein unfolding, and DNA deformation, insect cells may respond by upregulating antioxidant molecules, chaperone proteins, and DNA repair mechanisms. Enhancing our knowledge of insect-metal interactions sounds crucial for the conservation of insect populations in an increasingly metal-dependent world.

Visible light-driven photocatalytic degradation of atrazine in aqueous phase: impact of the g-C3N4/TiO2/NiFe2O4 nanocomposite activated by potassium peroxymonosulfate.

The present investigation focused on the photocatalytic degradation of aqueous atrazine over g-C3N4/TiO2/NiFe2O4 composite in the presence of peroxymonosulfate (PMS) under visible light irradiation. The ternary photocatalyst was synthesized and characterized using XRD, FTIR, nitrogen sorption, SEM, UV-Vis, and photoluminescence spectroscopy. This catalyst exhibited full absorption in the visible spectrum at 815nm and a high specific surface area of 105 m2/g. The effect of operating conditions encompassing atrazine initial concentration, photocatalyst loading, PMS concentration, and temperature on the degradation reaction extent was investigated. The obtained findings highlighted the efficiency of the ternary composite in the photocatalytic degradation of this widely used and environmentally harmful pesticide. The strategic addition of PMS was shown to be crucial to improving this efficiency. Indeed, in the presence of PMS at a concentration of 5mM, atrazine conversion reached 97.2% within 300min of reaction at ambient temperature with a photocatalyst loading of 0.3g/L. Furthermore, the activation energy of the reaction was evaluated to be 37.3kJ/mol. The present study showed the promising potential of the g-C3N4/TiO2/NiFe2O4 photocatalyst for environmental remediation, offering important perspectives in the fight against pesticide pollution.

Pesticide contamination and associated ecological risks in estuarine waters of Brazil's Legal Amazon.

Pesticide contamination remains a significant environmental concern globally, with important implications for aquatic ecosystems. Despite being one of the world's largest pesticide consumers, monitoring and assessment of pesticide pollution are limited in Brazil, especially in sensitive regions like the Amazon. In this study, the occurrence and environmental risks of 8 pesticides of different classes, namely alachlor, atrazine, chlorfenvinphos, isoproturon, irgarol, simazine, diuron, and its transformation product DCPMU (1-(3,4-dichlorophenyl)-3-methyl urea) were analysed in surface water of the São Marcos Estuarine Complex (SMEC) in two consecutive years. The quantification of the target compounds was performed using ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS). Suspected and untargeted screening analyses with ultra-high-performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) was also conducted to identify transformation products (TPs) and additional pesticides in water samples. All target pesticides, except for alachlor, were found in at least one sampling campaign. The antifouling biocides irgarol and diuron were ubiquitous in 2018 and 2019, with detection frequencies varying between 81 and 100% and maximum concentrations of 13.6ng L-1 and 17.1ng L-1, respectively. In 2019, the detection frequencies of the target pesticides were considerably higher than in 2018, with atrazine, isoproturon, and DCPMU being found in 100% of the samples. In 2019, chlorfenvinphos and isoproturon were the pesticides with the highest levels, reaching 48.6ng L-1 and 44.6ng L-1, respectively. The UHPLC-HRMS analysis showed the presence of the pesticides DEET (N,N-diethyl-meta-toluamide), octhilinone (2-Octyl-4-isothiazolin-3-one), and cyprodinil (4-cyclopropyl-6-methyl-N-phenylpyrimidin-2-amine) in water samples. Additionally, the TPs 2-hydroxy-atrazine, didemethylisoproturon (1-(4-isopropylphenyl)urea) and M1 (2-methylthio-4-tert-butylamino-6-amino-s-triazine) were found. The environmental risk assessment showed that irgarol was the primary contributor to the global risk quotient in the SMEC region. Similarly, chlorfenvinphos also showed a high risk to the local aquatic biota, especially in 2019. This research not only highlights the urgent need for improved pesticide monitoring in Brazil but also establishes a baseline for future studies and environmental management efforts in SMEC. We emphasize the importance of prioritising pollutants and implementing effective mitigation strategies to protect the fragile aquatic ecosystems of the Brazilian Amazon.

Pesticide Pollution in India: Environmental and Health Risks, and Policy Challenges

Intensive agriculture practices in India to meet the food demand of the increasing population have led to the use of agrochemicals such as pesticides in higher quantities to increase productivity resulting in contamination of the environment. Pesticides control pests, weeds, and diseases in plants, animals, and humans. Despite bans on pesticides such as organochlorides (OC), organophosphate (OP), or synthetic pyrethroids ranging from minimal to excessive, are detected in soil, surface water, and groundwater often exceeding WHO and BIS safety limits. The predominantly found pesticides were DDT, HCH, Endosulfan, malathion, chlorpyrifos, atrazine, endrin, cypermethrin, dichlorvos, etc. Different ranges of pesticides were detected in different states (Kashmir, UP, Tamil Nadu, Kerala, Rajasthan, Haryana, Assam, Madhya Pradesh, etc.) of India, which demonstrate that pesticides can persist in the environment and later can show bioaccumulation in the food chain. The article explores the consequences of this pollution such as biomagnification, bioaccumulation, and risks to human health and ecological integrity. This article also covers the adverse effects of pesticides such as carcinogenic, teratogenic, mutagenic, and endocrine-disrupting properties along with the importance of developing new policies or strengthening the current policies and regulations to monitor the use of pesticides.

Retraction notice to "Pesticide pollutants in the environment - A critical review on remediation techniques, mechanism and toxicological impact"[Chemosphere 301 (2022) 134754

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). <This article has been retracted at the request of the Editors-in-Chief. A journal-wide investigation by Elsevier's Research Integrity & Publishing Ethics team identified violations of the journal's policies on conflict of interest related to the submission and review of this paper. Review of this submission was handled by Guest Editor Pau Loke Show despite an extensive record of collaboration, including co-publication, with one of the paper co-authors (Dai-Viet N. Vo). Acceptance of the article was partly based upon the positive advice of a reviewer who was closely linked to one of the authors (Vo). This compromised the editorial process and breached the journal's policies. The authors disagree with this retraction and dispute the grounds for it.>.

Combined pollution of soil by heavy metals, microplastics, and pesticides: Mechanisms and anthropogenic drivers.

Soil is the foundation of terrestrial ecosystems and a critical resource for agricultural activities. This study investigated internal mechanism and interaction of heavy metals, pesticides (atrazine, pyrimazole and chlorpyrifos) and microplastics in soil. Specifically, certain sampling points exhibited elevated levels of individual heavy metals (Cd, Cr, Zn), exceeding the screening values, while both microplastics and pesticides demonstrated high variability, increasing the potential ecological risks. The interaction between microplastics, heavy metals, and pesticides is complex, involving electrostatic adsorption, surface complexation, biofilm mediation, and physical absorption. From a broader perspective, both heavy metals and microplastics were found to exacerbate the ecological risks posed by pesticides. Further, structural equation model and geographical weighted regression were used to reveal the driving mechanism behind complex pollution, with economic development emerging as a significant factor influencing pollution levels. These findings enhance our understanding of the combined pollution of heavy metals, microplastics, and pesticides.

Pesticide Contamination of Honey-Bee-Collected Pollen in the Context of the Landscape Composition in Latvia.

The honey bee (Apis mellifera) is the most widely managed pollinator and is vital for crop fertilization. Recently, bee colonies have been suffering high mortality rates, exacerbated by factors such as land-use changes and the use of pesticides. Our work aimed to explore the residues of pesticides in honey-bee-collected pollen and how this contamination was affected by seasonality and the landscape composition. We selected six apiaries from different landscapes in Latvia, and pollen samples were collected during the flowering season (2023). We analyzed 39 samples and found 21 pesticide residues (mainly fungicides) with a frequency of 93 occurrences where the values were above the limit of quantification. The most frequently encountered substances were acetamiprid, boscalid, fluopyram, and prothioconazole. However, the highest concentrations were for dimoxystrobin (44 µg kg-1), acetamiprid (37 µg kg-1), azoxystrobin (27 µg kg-1), prothioconazole (25 µg kg-1), and boscalid (15 µg kg-1). We then calculated the Pollen Hazard Quotient (PHQ) for each pollen sample. No sample had a PHQ value above the critical value of 50. The highest contamination level was observed in the first half of the vegetation season (the end of May and the beginning of June), but later, it significantly decreased. We did not find any significant influence of landscape composition on pesticide pollution.

Pesticide presence in stream water, suspended sediment and biofilm is strongly linked to upstream catchment land use and crop type

Pesticide pollution can present high ecological risks to aquatic ecosystems. Small streams are particularly susceptible. There is a need for reproducible and readily available methods to identify aquatic regions at risk of pesticide contamination. There is currently a limited understanding of the relationship between upstream catchment land use and the presence of pesticides in multiple aquatic matrices. The aim of this study was to develop empirical relationships between different land uses and the levels of pesticides detected in multiple aquatic matrices. The inclusion of biofilm and suspended sediment as monitoring matrices has recently been proven effective for the characterization of pesticide exposure in stream ecosystems. Ten streams in Ontario, Canada with a variety of upstream catchment land uses were sampled in 2021 and 2022. Water, suspended sediment and biofilm were collected and analyzed from each site for the presence of approximately 500 different pesticides. Each of the three matrices exhibited distinctive pesticide exposure profiles. We found a significant relationship between the percentage of agriculture and urban land use and the detection of multiple pesticides in water, sediment and biofilm (logistic regressions, P<0.05). Statistically significant probabilistic models capable of predicting pesticide detections based on upstream catchment land use were developed. High-resolution cover crop maps identified soybeans, corn and other agriculture (e.g., vegetables, berries, canola) as the key variables associated with individual pesticide detection frequencies in each of the three matrices (linear regressions, P<0.05). Soybean land use was also the strongest predictor of site-wide pesticide pollution. This modelling approach using upstream catchment land use variables has the potential to be a powerful tool to identify streams at risk of pesticide pollution.

Functional profiling of the rhizospheric Exiguobacterium sp. for dimethoate degradation, PGPR activity, biofilm development, and ecotoxicological risk

This study introduces an indigenous bacterial strain, Exiguobacterium sp. (L.O), isolated from sugarcane fields in Sevur, Tamil Nadu, which has adapted to prolonged exposure to dimethoate. The strain demonstrated the capability to utilize 150 ppm of dimethoate as its sole carbon source, achieving a remarkable degradation rate of 95.87% within 5 days in mineral salt media. Gas chromatography–mass spectrometry (GC–MS) analyses identified the presence of intermediate by-products formed during degradation, like methyl diethanol amine and aspartyl glycine ethyl ester. Notably, phosphorothioic O, O, S-acid, an expected end product in the degradation of dimethoate, was also identified, further confirming the strain’s effective metabolic breakdown of the pesticide. Further degradation study and analysis of changes in functional group was performed by FTIR, and a hypothetical degradation pathway was elucidated showing the course of dimethoate metabolism by the strain. Exiguobacterium sp. (L.O) also displayed significant plant growth-promoting traits, including the production of HCN, IAA, and ammonia and the formation of biofilms, which enhance its utility in agricultural applications. The ecotoxicity study revealed the degradation by-products exhibited reduced toxicity compared to the parent compound dimethoate, highlighting the strain’s potential not only for bioremediation but also for supporting sustainable agricultural practices. This research presents a novel application of Exiguobacterium sp. (L.O), integrating the bioremediation of the organophosphate pesticide dimethoate with agricultural enhancement. This approach is critical for addressing the challenges associated with pesticide pollution in agricultural practices. This study is likely the first to demonstrate the application of this strain in the degradation of dimethoate, as suggested by an extensive review of the literature.

Polyaromatic hydrocarbon and chlorinated pesticides pollution in Iacob Lake of Romania: radionuclide-dated sediments and chromatographic analysis

This study aims to assess the persistent organic pollutant (POP) pollution history of Iacob Lake, Danube Delta, Romania. For this purpose, 16 polycyclic aromatic hydrocarbons (PAHs) and 20 organochlorine pesticides (OCPs) were determined by gas chromatography coupled with specific detectors in the lake sediment core collected in 2014. Before POP analysis, the sediment layers were dated using the 210Pb dating method. The target compounds were isolated from the sediment by ultrasound-assisted extraction, followed by extract clean-up by open-column chromatography. The obtained results showed that between 1940 and 2012, the concentrations of PAHs and OCPs in the dry-weight sediment layers ranged from 73.81 to 214.54 ng g−1 and from 71.78 to 192.69 ng g−1, respectively. Different PAH and OCP diagnostic ratios were used to identify and assess pollution sources. Our results show that the main sources of PAHs in Iacob Lake are mixed petroleum spills, biomass, coal, and petroleum combustion, while OCP residues come from legacy uses. Referring to the Sediment Quality Guidelines, the mean effect range-median quotient, and the toxic equivalent factor, it was found that the highest ecological risks occurred for the pesticide DDT, while the ecological risk for PAHs was considerably low.

Pesticide pollution: toxicity, sources and advanced remediation approaches.

The Food and Agricultural Organization of the United Nations (FAO) estimates that food production must rise by 70% to meet the demands of an additional 2.3 billion people by 2050. This forecast underscores the persistent reliance on pesticides, making it essential to assess their toxicity and develop effective remediation strategies. Given the widespread utilisation of pesticides, it requires an urgent need to evaluate their toxicity and explore feasible remediation approaches for their removal. Hence, this review provides an overview of the latest information on the presence, distribution, sources, fate, and trends of pesticides in global environmental matrices, emphasizing the ecological and health risks posed by pesticide pollution. Currently, the dominant remediation techniques encompass physical, chemical, and biological methods, yet studies focusing on advanced remediation techniques remain limited. This review critically evaluates both newer and traditional approaches to pesticide removal, offering a descriptive and analytical comparison of various methods. The selection of the appropriate treatment method depends largely on the nature of the pesticide and the effectiveness of the chosen technique. In many cases, technologies such as membrane bioreactors and the fenton process could be integrated with biological technologies to enhance performance and overcome limitations. The study concludes that a hybrid approach combining various remediation strategies offers the most effective and sustainable solution for pesticide removal. Finally, the review underscores the need for further scientific investigation into the most viable technologies while discussing the challenges and prospects of developing safe, reliable, cost-effective, and eco-friendly methods for removing pesticides from the environment.

Optimized QuEChERS method in determination of multiresidues on high-risk leafy vegetables and monitoring data analysis from 2021 to 2023

Pesticide pollution poses significant risks to human health, ecosystem, and biodiversity. Among agro-products, leafy vegetables exhibited particularly severe pesticide residue due to their short harvest periods and large leaf surfaces. However, investigations on multiresidues in high-risk leafy vegetables based on Chinese dietary habits were still limited. In this study, we developed a weak basic citrate-buffered QuEChERS method for the simultaneous extraction of 43 pesticides in bok choy, celery, Chinese chive and cilantro. Coupled with the high-throughput UPLC-MS/MS technique, this method achieved LODs ranging from 0.1–3.0 μg/kg and LOQs ranging from 0.4–10.0 μg/kg for the four matrices with high sensitivity. The recovery experiments on blank samples indicated that the method recoveries were in the range of 76.2 %–116.3 %, with RSDs less than 12.1 %. The developed method provided a highly accurate and precise technical approach for the analyses of high-risk leafy vegetables. Furthermore, 211 vegetables were collected from markets in Hangzhou from 2021 to 2023. The total detection frequency was 92.9 %, and high detection frequencies for pesticides such as acetamiprid, carbendazim, clothianidin, dimethomorph, dinotefuran, imidacloprid, propiconazole, pyraclostrobin, and thiamethoxam. The distribution of pesticides in different vegetables varied significantly due to factors such as application amount and plant absorption, providing valuable insights for implementing targeted detection and regulatory interventions. The mixed use of multiple pesticides in cilantro was observed. Combined use of pesticides such as tebuconazole, difenoconazole, and propiconazole (all belonged to sterol demethylation inhibitors), might lead to pathogen resistance. In summary, the frequently detected pesticides in the four leafy vegetables presented acceptable dietary risks, with hazard quotients ranging from 0.005 % to 3.634 %.

Early Sweet Potato Plant Detection Method Based on YOLOv8s (ESPPD-YOLO): A Model for Early Sweet Potato Plant Detection in a Complex Field Environment

Traditional methods of pest control for sweet potatoes cause the waste of pesticides and land pollution, but the target detection algorithm based on deep learning can control the precise spraying of pesticides on sweet potato plants and prevent most pesticides from entering the land. Aiming at the problems of low detection accuracy of sweet potato plants and the complex of target detection models in natural environments, an improved algorithm based on YOLOv8s is proposed, which can accurately identify early sweet potato plants. First, this method uses an efficient network model to enhance the information flow in the channel, obtain more effective global features in the high-level semantic structure, and reduce model parameters and computational complexity. Then, cross-scale feature fusion and the general efficient aggregation architecture are used to further enhance the network feature extraction capability. Finally, the loss function is replaced with InnerFocaler-IoU (IFIoU) to improve the convergence speed and robustness of the model. Experimental results showed that the mAP0.5 and model size of the improved network reached 96.3% and 7.6 MB. Compared with the YOLOv8s baseline network, the number of parameters was reduced by 67.8%, the amount of computation was reduced by 53.1%, and the mAP0.5:0.95 increased by 3.5%. The improved algorithm has higher detection accuracy and a lower parameter and calculation amount. This method realizes the accurate detection of sweet potato plants in the natural environment and provides technical support and guidance for reducing pesticide waste and pesticide pollution.

Evaluation of Physicochemical Parameters of Water in Three Lakes of Dindigul District, Tamil Nadu, India

The investigator's goal was to evaluate the effects of pesticide pollution brought on by the vegetable market's wastewater outflow from nearby ponds in and around Dindigul town, Tamilnadu, India. The surrounding research area's ponds have been greatly impacted by the ongoing use of pesticides in these vegetable wastes. Three sampling sites were chosen for this study such as Sadayan, Lakshmi Puram and Nagammal pondss and samples were taken in the summer to examine critical parameters like total hardness, pH, dissolved carbon dioxide (CO2), dissolved oxygen (DO), chemical oxygen demand (COD), biological oxygen demand (BOD), chloride, total alkalinity, and total dissolved solids (TDS), as well as heavy metals. The results indicate that Sadayan Ponds is classified as severely polluted while compared other ponds. This investigation leads to the conclusion that the ponds's water is not appropriate for agriculture or for sustaining wildlife.

Protection of water resources from agricultural pressures: Embracing different knowledge domains in governance approaches

AbstractThe remediation of nitrate and pesticide pollution from agriculture in drinking water resources has manifested itself as a complex and multifaceted challenge in Europe and in other continents. Addressing agricultural pollution in water resources requires cross‐sectoral approaches. The EU Water Framework Directive aims to build bridges among these sectors, but the often sectoral implementation by Member States prevents its potential from being fully explored. This study aims to contribute to the body of interdisciplinary knowledge on the driving forces towards water quality improvement from agricultural pollution by case study research in five European countries in an interdisciplinary setting. The cases have shown that the added value of voluntary practices is considerable for creating shared ambitions but limited for actual water quality improvement. Implementation of strategies should be supported by practical guidance and monitoring of outcomes that enables compliance testing and refines simulation models for the formulation of follow‐up actions. Dynamic interactions among the knowledge domains, for example, social‐economic context, the legal framework, and the state of the water system, help to identify necessary actions at the different stages of the policy cycle. Especially in the implementation, monitoring, evaluation, and adaptation stage of the policy cycle, there is a need for further studies in order to improve effectiveness, for example on the role of monitoring and evaluation, licensing, and the issue of scale in cross‐sectoral approaches.

Tolerance pattern against the heavy metals and pesticides in Escherichia coli isolated from water samples.

In this study water samples were investigated for the presence of heavy metals and pesticide resistance in Escherichia coli (E. coli) collected from district Jhal Magsi. Identification of E. coli was carried out via Polymerase Chain Reaction (PCR) assays. Heavy metals and pesticide resistance were conducted by the Kirby-Bauer disk diffusion method. E. coli was confirmed by using uidA (623bp) and usp (515bp) genes primer. A relatively high resistance rate was observed for Cd and DDT (2, 4 D) with 100% at the concentration of 1600µl/mL. Samples showed the resistance pattern for Cr with 55% and sensitivity was 45% at 800µl/mL. Resistance and sensitive percentage of Pb, Co were observed 61, 63, and 39, 37% at 400µl/mL. Cyanazine resistance and the sensitive percentage were 51 and 49% at 800µg/mL. For Chlorpyrifos and Carbofuran, 54 and 65% resistance and sensitivity 46 and 35% were measured at a lower range of 400µl/mL. Excessive use of heavy metals and pesticide pollution in standing water near agriculture fields contributed to accelerating the abundance of multi-pollutant-resistant E. coli in water that could be useful in the bioremediation of pesticides and heavy metals.

Removal of Pesticides from Water by Adsorption on Activated Carbon Prepared from Invasive Plants

Pesticide pollution of surface water is a serious global problem. This research was focused on the monitoring of pesticides in surface waters and their subsequent removal using adsorption on activated carbon (AC). Based on the monitoring, four pesticides—acetamiprid, diethyltoluamide, thiacloprid and thiamethoxam—occurred in higher concentrations in all sampling points. Invasive plants occurring near monitored water bodies, Reynoutria japonica (RJ) and Impatiens glandulifera (IG) were used for the preparation of activated carbon with an activating agent (H3PO4 and NaOH) using microwave pyrolysis. The prepared AC was subsequently used for adsorption of the above-mentioned pesticides. The prepared AC was characterized by Brunauer–Emmett–Teller analysis, elemental analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. Individual AC types showed different effects for different pesticides. The maximum adsorption capacity calculated from the Langmuir model was 18.30 mg g−1 for thiacloprid on H3PO4-activated AC from I. glandulifera.

Antibiotic resistance genes transfer risk: Contributions from soil erosion and sedimentation activities, agricultural cycles, and soil chemical contamination

The transfer of antibiotic resistance genes (ARGs) pose environmental risks that are influenced by soil activity and pollution. Soil erosion and sedimentation accelerate degradation and migration, thereby affecting soil distribution and contamination. This study quantified the vertical and horizontal transfer capabilities of ARGs and simulated soil environments under various scenarios, such as erosion, agricultural cycles, and chemical pollution. The results showed that slope, runoff, and sediment volume significantly affected soil erosion and ARG transfer risks. The response of environmental factors to the transfer risk of ARGs is as follows: the promotion effect of soil deposition (average: 21.41 %) is significantly greater than the inhibitory effect of soil erosion (average: −11.31 %); the planting period (average: −64.654) is greater than the harvest period (average: −56.225); the response to soil chemical pollution is: the impact of phosphate fertilizer residues, antibiotics, and pesticide pollution is more significant. This study constructed a vertical and horizontal transfer system of ARGs in soil erosion and sedimentation environments and proposed a response analysis method for the impact of factors, such as soil erosion and sedimentation activities, agricultural cycles, and soil chemical pollution, on ARGs transfer capabilities.

Pollution of organophosphorus pesticides in the Dongting Lake, China and its relationship with dissolved organic matter: Occurrence, source identification and risk assessment

The escalating global demand for food and industrialization has placed significant pressure on the integrity and management of inland lake ecosystems. Herein, the organophosphorus pesticides (OPPs) pollution status and their relationship with dissolved organic matter (DOM) in Dongting Lake were investigated to identify the ecological risks and potential sources of OPPs. The total concentrations of 18 detected OPPs were in the range of 13.49–375.24 ng/L, with higher concentration observed in east and west lake regions. Among these, fenthion was the dominant contributor, accounting for 64% of total OPPs, posing significant ecological risk to aquatic organisms. Nearly all of sites showed high combined risk of total OPPs. Parallel factor analysis (PARAFAC) and fluorescence regional integration (FRI) technique showed that DOM was mainly composed of terrestrial humic-like and tryptophan-like substances. Moreover, correlation analysis revealed a close association between DOM optical parameters and OPP concentrations. Specifically, OPPs exhibited a significantly positive correlation with tyrosine-like substances, while displaying a negative correlation with fulvic acid-like substances. These results indicated that OPP concentrations may decrease with increasing humification levels and declining tyrosine-like substance contents. This study underscores the critical role of DOM in assessing the occurrence and sources of OPPs in aquatic environments, providing valuable insights for effective environmental management strategies.

Mitigating pesticide pollution: A comprehensive study on the biological treatment of clodinafop-propargyl and organic load in agricultural wastewater using a moving bed biofilm reactor (MBBR)

The widespread use of pesticides in modern agriculture poses significant threats to public health and the environment. Addressing the growing environmental and economic concerns requires effective strategies for removing and mitigating agricultural toxins. This study evaluates the efficiency of a Moving Bed Biofilm Reactor (MBBR) in degrading clodinafop-propargyl (CF) and reducing organic matter in a controlled laboratory setting. The research focuses on initial CF concentration and hydraulic retention time (HRT) as key factors influencing removal efficiency. The biodegradation of CF was systematically carried out using the MBBR bioreactor. Results demonstrated maximum removal efficiencies of 82.51 % for CF, 88.78 % for Chemical Oxygen Demand (COD), 89.58 % for Total Phosphorus (TP), and 86.31 % for Total Nitrogen (TN). These findings highlight the MBBR's strong capability in eliminating CF and reducing nitrogen in wastewater, positioning it as a cost-effective and environmentally sustainable solution for pesticide pollution. The novelty of this study lies in its detailed examination of the MBBR's performance under varying operational conditions, providing critical insights into its efficiency and optimization. Overall, this research offers valuable contributions to environmental engineering, presenting a promising method for treating pesticide-laden agricultural wastewater and supporting sustainable farming practices.