A spatial approach to identify priority areas for pesticide pollution mitigation

Evaluation of an open-source nutrient delivery model for estimating pesticide loads in river catchments

Quantifying pesticide runoff hazard in catchments is necessary to predict the impacts and target mitigation. Achieving this at scale through regular, long-term water quality monitoring at multiple sites is time- and resource-intensive. Ideally, such monitoring should be supplemented by models that can estimate pesticide loads in a quicker, less costly manner, especially for unmonitored catchments. We developed a novel modelling method combining the Integrated Valuation of Ecosystem Services and Tradeoffs Nutrient Delivery Ratio (InVEST® NDR) model and the UKCEH Land Cover® plus: Pesticides maps to estimate pesticide load across England. The InVEST NDR model is a widely used, open-source pollutant runoff model, but has not yet been evaluated for use with pesticides. We compared our modelled approach with a measurement-based ("measured") approach. This measured approach used pesticide concentration data from the Environment Agency and river flow data using Qube (a water resource estimation tool) for catchments upstream of the sampling sites: 54 for bentazone and 21 for chlorotoluron. The significant positive relationships between measured and modelled pesticide loads were stronger when the measured approach accounted for the proportionate area of arable land cover, presumably because the modelled approach only incorporated pesticides from arable sources, explaining up to 90 % of the variation in relative hazard between catchments. Thus, our modelled method forms a flexible approach to mapping relative pesticide runoff hazard over large spatial extents, especially where monitoring is limited. It could also be used to rapidly prioritise catchments for more complex analysis to produce accurate measures of absolute loads.

Pinosylvin: A Multifunctional Stilbenoid with Antimicrobial, Antioxidant, and Anti-Inflammatory Potential

Stilbenoids are a category of plant compounds exhibiting notable health-related benefits. After resveratrol, perhaps the most well-known stilbenoid is pinosylvin, a major phytochemical constituent of most plants characterised by the pine spines among others. Pinosylvin and its derivatives have been found to exert potent antibacterial and antifungal effects, while their antiparasitic and antiviral properties are still a subject of ongoing research. The antioxidant properties of pinosylvin are mostly based on its scavenging of free radicals, inhibition of iNOS and protein kinase C, and promotion of HO-1 expression. Its anti-inflammatory properties are based on a variety of mechanisms, such as COX-2 inhibition, NF-κB and TRPA1 activation inhibition, and reduction in IL-6 levels. Its anticancer properties are partly associated with its antioxidant and anti-inflammatory potential, although a number of other mechanisms are described, such as apoptosis induction and matrix metalloproteinase inhibition. A couple of experiments have also suggested a neuroprotective potential. A multitude of ethnomedical and ethnobotanical effects of pinosylvin-containing plants are reported, like antimicrobial, antioxidant, anti-inflammatory, hepatoprotective, and prokinetic actions; many of these are corroborated by recent research. The advent of novel methods of artificial pinosylvin synthesis may facilitate its mass production and adoption as a medical compound. Finally, pinosylvin may be a tool in promoting environmentally friendly pesticide and insecticide policies and be used in land remediation schemes.

CLAMity: Mixtures of agricultural pesticides as multiple stressors in a bivalve species

Pesticides play a vital role in ensuring global food security amid a growing global population; however, their movement away from application sites can pose significant risks to the health of non-target species. Pollution of freshwater is a key contributor to the high extinction rates of freshwater species, which often face exposure to a complex "cocktail" of pollutants simultaneously. A better understanding of pesticide interactions will enable more targeted policies and land management practices to mitigate environmental damage while ensuring food security. In this study, Corbicula fluminea (Asian clam) were exposed to binary pesticide mixtures commonly found in two rivers in the South of England. The exposures involved individual pesticides and mixtures at a concentration of 0.1μg/L per pesticide. Selected molecular markers were targeted and proved to be impacted by the timing and the pesticide mixture; an Integrated Biomarker Response (V2) value was also calculated. Our results show that both seasonality and the chemicals characteristics of the pesticides may significantly modulate their toxicity, both individually and in a mixture. When put into the context of catchment management this data combined with pesticide monitoring could improve estimating ecological risk. To the authors' knowledge, this is the first study to assess the molecular responses of these mixtures in bivalve molluscs using the IBRv2 value following exposure to combined pesticides.

The power to (detect) change: Can honey bee collected pollen be used to monitor pesticide residues in the landscape?

Analysis of trapped honey bee pollen for pesticide residues is the most widely used method of monitoring the amount of pesticide entering colonies and its change over time. In this study, we collected and analyzed pollen from 70 sites across four bee-pollinated crops over two years to characterize the variation in pesticide detection across sites, crops and at different periods during bloom. Hazard Quotient, HQ, is the most common way that pesticide residues are aggregated into a single pesticide hazard value in the current literature. Therefore, change in pesticide hazard (HQ) was quantified in composite pollen samples collected from pollen traps and in pollen color subsamples separated into pollen from the target crop being pollinated and pollen from other plant species. We used our estimates of the variation in HQ to calculate the number of sample location sites needed to detect a 5% annual change in HQ across all crops or within specific crops over a 5-year period. The number of sites required to be sampled varied by crop and year and ranged between 139 and 7194 sites, costing an estimated $129,548 and $3.35 million, respectively. The HQ values detectable for this cost would be 575 and 154. We identified additional factors that complicate the interpretation of the results as a way to evaluate changes in pest management practices at a state level. First, in all but one crop (meadowfoam), the pollen collected from outside the crop honey bee colonies were pollinating comprised a major percentage of the total pollen catch. Moreover, we found that when the overall quantity of pollen from different pollen sources was taken into account, differences in HQ among crops widened. We also found that while HQ estimates remain consistent across the bloom period for some crops, such as cherry, we observed large differences in other crops, notably meadowfoam. Overall, our results suggest the current practice of interpreting pesticides levels in pollen may come with limitations for agencies charged with improving pesticide stewardship due to the high variation associated with HQ values over time and across crops. Despite the limitations of HQ for detecting change in pesticide hazard, there remains a potential for HQ to provide feedback to regulators and scientists on field-realistic pesticide hazard within a landscape.

Mitigating glyphosate levels in surface waters: Long-term assessment in an agricultural catchment in Belgium

The increasing concern over pesticide pollution in water bodies underscores the need for effective mitigation strategies to support the transition towards sustainable agriculture. This study assesses the effectiveness of landscape mitigation strategies, specifically vegetative buffer strips, in reducing glyphosate loads at the catchment scale under realistic conditions. Conducted over six years (2014-2019) in a small agricultural region in Belgium, our research involved the analysis of 732 water samples from two monitoring stations, differentiated by baseflow and event-driven sampling, and before (baseline) and after the implementation of mitigation measures. The results indicated a decline in both the number and intensity of point source losses over the years. Additionally, there was a general decrease in load intensity; however, the confluence of varying weather conditions (notably dry years during the mitigation period) and management practices (the introduction of buffer strips) posed challenges for a statistically robust evaluation of each contributing factor. A reduction of loads was measured when comparing mitigation with baseline, although this reduction is not statistically significant. Glyphosate loads during rainfall events correlated with a rainfall index and runoff ratio. Overall, focusing the mitigation strategy on runoff and erosion was a valid approach. Nevertheless, challenges remain, as evidenced by the continuous presence of glyphosate in baseflow conditions, highlighting the complex dynamics of pesticide transport. The study concludes that while progress has been made towards reducing pesticide pollution, the complexity of interacting factors necessitates further research. Future directions should focus on enhancing farmer engagement in mitigation programs and developing experiments with more intense data collection that help to assess underlying dynamics of pesticide pollution and the impact of mitigation strategies in more detail, contributing towards the goal of reducing pesticide pollution in water bodies.

A review of modeling pesticides in freshwaters: Current status, progress achieved and desirable improvements

This study comprises a critical review of modeling of pesticides in surface waters. The aim was to update the status of the use of models to simulate the fate of pesticides from diffuse sources. ISI papers were selected on Scopus and the information concerning the study areas, type of pesticides (herbicides, fungicides and insecticides), the model, and the methodology adopted (i.e., calibration and/or validation, spatial and temporal scales) were analyzed. The studies were carried out in Europe (55.5%), North America (22.3%), Asia (13.9%) and South America (8.3%). The Soil and Water Assessment Tool proved to be the most used model (45.95%). Herbicides were the most modeled pesticides (71.4%), followed by insecticides (18.2%) and fungicides (10.4%). The main herbicides modeled were atrazine, metolachlor, isoproturon, glyphosate, and acetochlor. Insecticides such as chlorpyrifos and metaldehyde. Chlorothalonil, and fungicides (i.e., tebuconazole) were the most widely investigated. Based on published studies, it was found that modeling approaches for assessing the fate of pesticides are constantly evolving and the model algorithms work well with diverse watershed conditions, management strategies, and pesticide properties. Several papers reported concentrations of pesticides exceeding ecotoxicological thresholds revealing that water contamination with pesticides used in agriculture and urban areas is a priority issue of current global concern.

UV-Vis Activated Cu2O/SnO2/WO3 Heterostructure for Photocatalytic Removal of Pesticides

A three-steps sol–gel method was used to obtain a Cu₂O/SnO₂/WO₃ heterostructure powder, deposited as film by spray pyrolysis. The porous morphology of the final heterostructure was constructed starting with fiber-like WO₃ acting as substrate for SnO₂ development. The SnO₂/WO₃ sample provide nucleation and grew sites for Cu₂O formation. Diffraction evaluation indicated that all samples contained crystalline structures with crystallite size varying from 42.4 Å (Cu₂O) to 81.8 Å (WO₃). Elemental analysis confirmed that the samples were homogeneous in composition and had an oxygen excess due to the annealing treatments. Photocatalytic properties were tested in the presence of three pesticides—pirimicarb, S-metolachlor (S-MCh), and metalaxyl (MET)—chosen based on their resilience and toxicity. The photocatalytic activity of the Cu₂O/SnO₂/WO₃ heterostructure was compared with WO₃, SnO₂, Cu₂O, Cu₂O/SnO₂, Cu₂O/WO₃, and SnO₂/WO₃ samples. The results indicated that the three-component heterostructure had the highest photocatalytic efficiency toward all pesticides. The highest photocatalytic efficiency was obtained toward S-MCh (86%) using a Cu₂O/SnO₂/WO₃ sample and the lowest correspond to MET (8.2%) removal using a Cu₂O monocomponent sample. TOC analysis indicated that not all the removal efficiency could be attributed to mineralization, and by-product formation is possible. Cu₂O/SnO₂/WO₃ is able to induce 81.3% mineralization of S-MCh, while Cu₂O exhibited 5.7% mineralization of S-MCh. The three-run cyclic tests showed that Cu₂O/SnO₂/WO₃, WO₃, and SnO₂/WO₃ exhibited good photocatalytic stability without requiring additional procedures. The photocatalytic mechanism corresponds to a Z-scheme charge transfer based on a three-component structure, where Cu₂O exhibits reduction potential responsible for O₂ production and WO₃ has oxidation potential responsible for HO· generation.

Mapping agricultural use of pesticides to enable research and environmental health actions in Belgium

Given the many public health and environmental impacts associated with the use of pesticides, comprehensive pesticide application data are a high priority for environmental and health professionals, government agencies, and community groups in Wallonia (Belgium). In that context, geographic information system (GIS) approaches for mapping estimates of agricultural pesticide use were developed in the present study. Data on pesticide application rates and high-resolution annual datasets of the geographic distribution of crops were used to complete this analysis in Wallonia over the period 2015-2017. The method was implemented in Python in order to allow easy update and improvements of maps, or to segment maps by individual pesticides, chemical groups of pesticides (e.g. insecticides, herbicides), etc. Linked databases were created to classify, select, and possibly weight AIs according to specific requests and criteria. The results provide a first map of agricultural pesticide use in Wallonia, which depicts the best picture up to now of their geographic distribution. Maps of fungicides, herbicides, and plant growth regulators showed quite similar spatial patterns as the map of the combination of all pesticides. In contrast, the insecticide map showed a specific pattern related almost exclusively to dwarf-tree orchards in some municipalities in northern Wallonia. This research work is a preliminary result on the spatial characterization of agricultural pesticide use in Wallonia and give a valuable basis for research and environmental health actions in Belgium. Forthcoming developments will focus on exposure characterization to agricultural pesticides using GIS models. Using this information, policymakers will able to detect potential priority zones and take action to check and reduce agricultural pesticide loads in the environment.

Fungal and bacterial assisted bioremediation of environmental toxicant (N-[2-[3-chloro-5-(trifluoromethyl)-2-pyridinyl] ethyl]-2-(trifluoromethyl) benzamide) holding benzamidic genesis elucidating the eco-friendly strategy

Fluopyram (FLP) containing benzamidic genesis utilized for seed detoxification and as a foliar application is associated with low profound toxicity in mammals but long-term toxicology investigations have revealed that FLP can stimulate tumor growth. FLP attenuation has been the first time scrutinized employing microorganisms originally identified from soils. Biodegrative assays of four fungal strains; Aspergillus fumigatus (AFu), Aspergillus terreus (AT), Aspergillus flavus (AF), Aspergillus niger (AN), and three bacterial strains: Streptococcus pneumoniae (SP) Streptococcus pyogenes (SPy), and Escherichia coli (EC), were employed. Ten milligrams per liter FLP concentration was made employing separately microbe and analyzed for 35 days. The analytical technique was inclusive of ultraviolet-visible spectrophotometric and high-performance liquid chromatography procedure endeavored to test FLP biodegradation. SP and AT exhibited maximal potentiality to metabolize FLP. HPLC is indicative of several metabolites formations. FLP degradation by AFu, EC, SPy, AN, AF, AT, SP was observed to be 24.2%, 82.7%, 89.8%, 90.7%, 91.3%, 95.4%, and 99.3%, explicating the efficacy of all strains employed in FLP degradation. Current investigations are indicative of significant bioremediation strategies for xenobiotic mitigation. Furthermore, the current examinations are inclusive of the augmentation of biodegradative assays to be utilized on a large scale for efficient environmental management cost-effectively and sustainably.

Multiple pesticides in lentic small water bodies: Exposure, ecotoxicological risk, and contamination origin

Lentic small water bodies (LSWB) are a highly valuable landscape element with important ecosystem services and benefits for humans and the environment. However, data about their pesticide contamination dynamic and the associated ecotoxicological effects are scarce. To overcome these knowledge gaps, five LSWBs located in agricultural fields in Northern Germany were studied during the spring pesticide application period (April to July 2018) and the concentrations of 94 pesticides were measured in weekly intervals. The goals of this study were to observe the trends of pesticide contamination during the application period, assess the ecotoxicity of the contamination, and assign the findings to temporal and spatial origins. Samples contained pesticide concentrations between 0.12 and 4.83 μg L^-1 as sums. High detection frequencies (81% of samples) and concentrations (max 1.2 μg L^-1) were observed for metazachlor transformation products. Contamination from multiple pesticides was detected with up to 25 compounds per sample and a maximum of 37 compounds per LSWB during the entire sampling period. High toxicities for algae and macrophytes were recorded using toxic units (TU) of -0.2 to -3.5. TUs for invertebrates were generally lower than for algae/macrophytes (-2.7 to -5.2) but were also recorded at levels with ecological impacts. Pesticide detections were separated into four categories to assign them to different temporal and spatial origins. Pesticides from the spring (5-11%) and the previous autumn (0-36%) application periods were detected in the LSWB. Some pesticides could be related to the application of the previous crop on the same field (0-39%), but most of the compounds (44-85%) were not related to the crop management in the last two years on the respective LSWB fields. The relevance of different input pathways is still unknown. Particularly, the effect of long-distance transport needs to be clarified to protect aquatic biota in LSWBs.

Insights into glyphosate removal efficiency using a new 2D nanomaterial

Glyphosate (GLY) is a nonselective herbicide that has been widely used in agriculture for weed control. However, there are potential genetic, development and reproduction risks to humans and animals associated with exposure to GLY. Therefore, the removal of this type of environmental pollutants has become a significant challenge. Some of the two-dimensional nanomaterials, due to the characteristics of hydrophilic nature, abundant highly active surficial sites and, large specific surface area are showed high removal efficiency for a wide range of pollutants. The present study focused on the adsorption behavior of GLY on silicene nanosheets (SNS). In order to provide more detailed information about the adsorption mechanism of contaminants on the adsorbent's surface, molecular dynamics (MD) and well-tempered metadynamics simulations are performed. The MD results are demonstrated that the contribution of the L-J term in pollutant/adsorbent interactions is more than coulombic energy. Furthermore, the simulation results demonstrated the lowest total energy value for system-A (with the lowest pollutant concentration), while system-D (contains the highest concentration of GLY) had the most total energy (E tot: -78.96 vs. -448.51 kJ mol-1). The well-tempered metadynamics simulation is accomplished to find the free energy surface of the investigated systems. The free energy calculation for the SNS/GLY system indicates a stable point in which the distance of GLY from the SNS surface is 1.165 nm.

Toward harmonizing global pesticide regulations for surface freshwaters in support of protecting human health

To promote international collaboration on environmental pollution management and human health protection, we conducted a global-level study on the management of pesticides for surface freshwater quality. Prior to actions being taken in terms of water treatment or remediation, it is essential that clear and definite regulations be disseminated. In our study, 3094 surface freshwater quality standards for 184 different pesticides were recorded from 53 countries and categorized according to pesticide types and standard types, as well as diverse use of freshwater by humans, and compared water quality standards related to human health. Our results indicate large variations in pesticide regulations, standard types (i.e., long- or short-term water quality standards), and related numerical values. With regard to the protection of human health, the 10 most frequently regulated pesticides account for approximately 47% of the total number of standards across 184 considered pesticides. The average occurrence-weighted variations of standard values (i.e., numerical values provided in a standard in terms of residue limits of a given pesticide in water) for the 20 most regulated persistent organic pollutants (POPs) and other phase-out pesticides (i.e., pesticides not currently-approved for use in agriculture across various countries) are 4.1 and 2.6 orders of magnitude, respectively, with human-exposure related standard values for some pesticides varying with over 3 orders of magnitude (e.g., lindane). In addition, variations in water quality standard values occurred across standard types (e.g., maximum and average), water use types (e.g., unspecified waters and human consumption), and standard values (e.g., pesticide individuals and groups). We conclude that regulatory inconsistencies emphasize the need for international collaboration on domestic water treatment, environmental management as well as specific water quality standards for the wider range of current-use pesticides, thereby improving global harmonization in support of protecting human health.

Carboxin and Diuron Adsorption Mechanism on Sunflower Husks Biochar and Goethite in the Single/Mixed Pesticide Solutions

The study focused on the adsorption mechanism of two selected pesticides: carboxin and diuron, on goethite and biochar, which were treated as potential compounds of mixed adsorbent. The authors also prepared a simple mixture of goethite and biochar and performed adsorption measurements on this material. The adsorbents were characterized by several methods, inter alia, nitrogen adsorption/desorption, Boehm titration, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The adsorption study included kinetics and equilibrium measurements, in the solution containing one or two pesticides simultaneously. The adsorption data were fitted to selected theoretical models (e.g., Langmuir, Freudlich, Redlich-Peterson, pseudo first-order and pseudo second-order equations). Based on the obtained results, it was stated that, among all tested adsorbents, biochar had the highest adsorption capacity relative to both carboxin and diuron. It equaled 0.64 and 0.52 mg/g, respectively. Experimental data were best fitted to the pseudo second-order and Redlich-Peterson models. In the mixed systems, the adsorption levels observed on biochar, goethite and their mixture were higher for diuron and lower for carboxin, compared to those noted in the single solutions. The presented results may enable the development of new mixed adsorbent for remediation of soils polluted with pesticides.

Application Intensity and Spatial Distribution of Three Major Herbicides from Agricultural and Nonagricultural Practices in the Central Plain of Thailand

The herbicides glyphosate, paraquat, and 2,4-D play a significant role in Thailand. This paper is among the first study to describe the intensity of herbicide application and illustrate how the herbicides are extensively distributed over a large area through both agricultural and nonagricultural practices. Using a quick, economical, and simplified method of Material Flow Analysis together with spatial analysis, better data for the analysis of possible environmental herbicide contamination, human exposure, and related health risks for the general public and applicators can be developed. The findings from this study showed that in the study province, about 2.2 million kg of the active ingredients from the three targeted herbicides is applied annually. Pathway flow modeling with spatial analysis identified several local hotspots of concern based on the type of herbicide and crop/activity where it was used. Cassava planting was found to have the highest herbicide application activity, whereas rice cultivation was the major contributor of total herbicide mass, due to the wide area of cultivation in the province. The herbicide most likely to be applied at rates higher than recommended was 2,4-D, particularly on cassava and sugarcane farms.

A Review on Prediction Models for Pesticide Use, Transmission, and Its Impacts

The lure of increased productivity and crop yield has caused the imprudent use of pesticides in great quantity that has unfavorably affected environmental health. Pesticides are chemicals intended for avoiding, eliminating, and mitigating any pests that affect the crop. Lack of awareness, improper management, and negligent disposal of pesticide containers have led to the permeation of pesticide residues into the food chain and other environmental pathways, leading to environmental degradation. Sufficient steps must be undertaken at various levels to monitor and ensure judicious use of pesticides. Development of prediction models for optimum use of pesticides, pesticide management, and their impact would be of great help in monitoring and controlling the ill effects of excessive use of pesticides. This paper aims to present an exhaustive review of the prediction models developed and modeling strategies used to optimize the use of pesticides.

Spatiotemporal pattern models for bioaccumulation of pesticides in common herbaceous and woody plants

Pesticides are widely used in agriculture, but they can bioaccumulate in plants, entering the food chain and potentially threaten human health. Thus, this study explored the spatiotemporal patterns of pesticide bioaccumulation in plants from soil using a spatiotemporal model. Air temperature (T_Air) and relative humidity (RH_Air) were selected as the principal spatiotemporal indicators to characterize the seasonal and geographical variation of the pesticide bioaccumulation factors (BAFs; i.e., the pesticide concentration ratio of plant to soil) of the leaves of common plants. The simulation results indicate that hot and dry climates typically increase the pesticide BAFs by enhancing the transpiration rate of plants. For example, the annual average BAF of alachlor was 5.75 in Arizona, while the BAFs in states with cold and humid weather, such as Maine, were below 2.00. Additionally, the monthly average BAF of alachlor during hot seasons can be double that of other seasons in the same region. For some pesticides, the simulated BAF intervals were consistent with those reported in the literature, whereas for others, the results were inconsistent. The major reasons for these inconsistencies include differences in the pesticide application scenarios, the distribution of pesticides in different compartments, and insufficient field data for some pesticides. We also applied the simulated BAFs of pesticide in plant leaves to address the seasonal and geographical health risks of herbivores, which could help regulate pesticide standards in ecological soils.

Using a multi-dimensional approach for catchment scale herbicide pollution assessments

Worldwide herbicide use in agriculture, whilst safeguarding yields also presents water quality issues. Controlling factors in agricultural catchments include both static and dynamic parameters. The present study investigated the occurrence of herbicides in streams and groundwater in two meso-scale catchments with contrasting flow controls and agricultural landuse (grassland and arable land). Using a multi-dimensional approach, streams were monitored from November 2018 to November 2019 using Chemcatcher® passive sampling devices and groundwater was sampled in 95 private drinking water wells. The concentrations of herbicides were larger in the stream of the Grassland catchment (8.9-472.6 ng L^-1) dominated by poorly drained soils than in the Arable catchment (0.9-169.1 ng L^-1) dominated by well-drained soils. Incidental losses of herbicides during time of application and low flows in summer caused concentrations of MCPA, Fluroxypyr, Trichlorpyr, Clopyralid and Mecoprop to exceeded the European Union (EU) drinking water standard due to a lack of dilution. Herbicides were present in the stream throughout the year and the total mass load was higher in winter flows, suggesting a persistence of primary chemical residues in soil and sub-surface environments and restricted degradation. Losses of herbicides to the streams were source limited and influenced by hydrological conditions. Herbicides were detected in 38% of surveyed drinking water wells. While most areas had concentrations below the EU drinking water standard some areas with well-drained soils in the Grassland catchment, had concentrations exceeding recommendations. Individual wells had concentrations of Clopyralid (619 ng L^-1) and Trichlorpyr (650 ng L^-1). Despite the study areas not usually associated with herbicide pollution, and annual mass loads being comparatively low, many herbicides were present in both surface and groundwater, sometimes above the recommendations for drinking water. This whole catchment assessment provides a basis to develop collaborative measures to mitigate pollution of water by herbicides.

Effective Remediation Strategy for Xenobiotic Zoxamide by Pure Bacterial Strains, Escherichia coli, Streptococcus pyogenes, and Streptococcus pneumoniae

Zoxamide, a class IV hazardous fungicide, is perilous for the environment due to its highly persistent nature. Up till the current date, there are no reports on the biodegradation of zoxamide. The scarcity of knowledge in this domain led to the present research to evaluate the biodegradation of this benzamide fungicide by three bacterial strains, Escherichia coli (EC), Streptococcus pyogenes (SPy), and Streptococcus pneumoniae (SP). Biotransformation of zoxamide was scrutinized in nutrient broth assemblies for a period of 28 days followed by UV-visible spectrophotometer and GC-MS analysis of the metabolites. The results exhibited a low to medium biodegradation potential of the bacterial cells to metabolize zoxamide. The highest biotransformation percentage was observed by E. coli to be 29.8%. The order of half-life calculated for the degradation results was EC (42.5) < SPy (58.7) < SP (67.9) days. GC-MS analysis indicated the formation of several metabolites including, 2-(3,5-dichloro-4-methylphenyl)-4-ethyl-4-methyl-4H-1,3-oxazin-5(6H)-one, 3,5-dichloro-N-(3-hydroxy-1-ethyl-1-methyl--2-oxopropyl)-4-methylbenzamide and 3,5-dichloro-4-methylbenzamide. The research could influence the biotreatment strategies for the environmentally friendly eradication of xenobiotics.

Pillar[5]arene Promoted Selective Spreading of Chlormequat Droplets on a Hydrophobic Surface

Promoting the spreading and deposition of agricultural sprays on the crop surface is of great significance for effective utilization of these chemicals. Selective host-guest interaction established between chlormequat and hydroxyl pillar[5]arene was well utilized in the present work for effective spreading of chlormequat droplets over the hydrophobic surface, which was silanized with triethoxy (octyl) silane and then assembled with hydroxybenzene pillar[5]arene molecules. Therefore, this surface was facile for the assembly of chlormequat in droplets and ultimately increased the selective adhesion of chlormequat through host-guest interactions. Moreover, the pillar[5]arene-fabricated surface shows considerable potential applications for rapid detection of chlormequat in environmental monitoring and also provides a novel approach for improving the chlormequat efficiency.