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Background: The European Water Framework Directive (WFD) has been implemented to achieve a good ecological status in European water bodies requiring macrophyte community assessment as one of the biological quality elements (BQEs). While in several lakes in Schleswig-Holstein (Germany) different BQEs improved within recent years, no recovery of macrophyte communities in some lakes could be achieved, despite the reduction of nutrient input and eutrophication. Due to the fact that no impairment of phytoplankton could be observed, toxic stress due to sediment contamination was hypothesized as a possible limiting factor of macrophyte community recovery. Results: Sediment toxicity was investigated by performing an extensive chemical screening of sediment contamination and a risk assessment based on toxic unit (TU) summation, using equilibrium water concentrations and algal toxicity as surrogates for lacking data on macrophyte toxicity. Possible indirect risks via toxic pressure on grazer were assessed via TUs based on crustaceans. The study revealed algal TUs of more than one order of magnitude below chronic toxicity thresholds in lakes with high and good status of the macrophyte community and increasing concentrations and frequency of exceedance of toxicity thresholds for lakes with moderate-to-bad status. The antifouling biocides irgarol and diuron were identified as major risk drivers. In addition, PAHs and glyphosate could not be ruled out to contribute to toxic pressure on macrophytes. Despite exceedance of toxicity thresholds for crustaceans, no connection of the ecological status of the macrophyte communities with toxic risks to grazers could be observed. Conclusions: Our study suggests that in a multiple pressure situation the toxic pressure created due to the contamination of sediments with antifouling biocides is one of the limiting factors for the recovery of macrophyte communities in impaired lakes of Schleswig-Holstein. This finding is in agreement with a Europe-wide survey on almost 47,000 sites suggesting that no good ecological status can be observed at sites with contamination exceeding toxicity thresholds. Similar to the survey, our study indicates additional stressors preventing the achievement of a good quality status of the lake ecosystems. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the effects of biochar addition on agrochemical leaching in tropical soils of Belize. Biochars were produced from mixed softwood, rice husk and miscanthus straw, each pyrolysed at 700°C. Loam, sandy silt loam and clay loam tropical soils were amended with 0, 1, 2.5 and 5% (w/w) biochar to determine atrazine, diuron, enrofloxacine, oxytetracycline and tetracycline absorption in batch studies following OECD 106 guidelines. FOCUS groundwater modelling was performed with the results of the batch‐sorption study and alterations to the soil profiles to explore the effect of biochar amendment on the leaching of atrazine in a risk assessment context. Results showed that agrochemical sorption was higher in biochar‐amended soils than soils without biochar amendment. Soil organic matter content and biochar amendment contributed to the agrochemical sorption increase in soils. The FOCUS modelling showed a significant reduction in predicted environmental concentration in groundwater (PECgw) of atrazine when biochar was applied as a soil amendment. However, a trade‐off was identified between the sorptive capacity of the biochar and the changes in hydrology in the soil as a result of the biochar incorporation. The amendment of Belizean tropical soils with rice husk biochar was shown to be an effective method to reduce the leaching of the selected agrochemicals, although widespread implementation should be conducted carefully, taking account of the potential trade‐offs with biochar use identified in our modelling. Highlights: Biochar‐amended soil is a feasible method to increase sorption and reduce agrochemical leaching to groundwater.Environmental fate modelling demonstrated that 1% and 2.5% biochar amendment could reduce atrazine leaching in soil.Modelling identified a biochar performance trade‐off: altered soil hydrology could lead to greater leaching.Biochar implementation must account for trade‐offs identified to ensure the mitigation works in each circumstance. [ABSTRACT FROM AUTHOR]

This paper reports the development of carbon paste electrode (CPE) modified with biochar (BC) and copper(II) 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H,31 phtalocyanine (CuHPc) used for the sensitive and selective detection of glyphosate in different matrices. The characterizations of the materials were performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FTIR). The analytical efficiency of the modified electrodes (CuHPc/CPE and BC-CuHPc/CPE) used for glyphosate detection was evaluated by square-wave voltammetry (SWV). The application of BC-CuHPc/CPE resulted in an improvement in the electron transfer process on the electrode surface, and this led to an outstanding increase of 100% in its current signal compared to CuHPc/CPE. Under optimized conditions, the BC-CuHPc/CPE sensor presented a linear concentration range of 0.3–4 µmol L−1 and a limit of detection of 0.02 µmol L−1. Interference analysis was conducted using different compounds that can be found in the environment including 2,4-D, atrazine, diuron, urea, and caffeine; the results obtained showed that the compounds did not exert any interference in the current peak of the glyphosate. The proposed method was applied for the determination of glyphosate in river water and food samples, where recovery rates of nearly 100% were obtained. The results demonstrate the accuracy and reliability of the proposed modified electrode. [ABSTRACT FROM AUTHOR]

The use of pre-emergent herbicides is an important tool in weed management. Sulfentrazone + diuron mixture was recently launched onto the market. The objective of this work was to evaluate the weed control and the agronomic performance of soybean in response to application of sulfentrazone + diuron doses in pre-emergence. The experiment was conducted in Londrina PR, in an oxisol. The treatments were doses of sulfentrazone + diuron (62 + 123, 123 + 245, 184 + 368, 245 + 490, 306 + 613 e 368 + 735 g a.i. ha-1). In addition to these treatments, isolated applications of sulfentrazone (245 g a.i. ha-1) and diuron (490 g a.i. ha-1) were evaluated, as well as a weedy and a weed-free control. For the weed control, the wild radish (Raphanus raphanistrum) and itchgrass (Rottboellia cochinchinensis) emergence were evaluated. In soybean, photosystem II (PSII) activity, stand, plant height, number of pods per plant, height of insertion of the first pod, number of nodes per plant, mass of a thousand grains and grain yield were evaluated. Results show that the mixture of sulfentrazone + diuron resulted in less than 50% wild radish control, regardless of the dose evaluated. However, for itchgrass, the control was greater than 90% in doses from 123 g sulfentrazone + 245 g diuron a.i. ha-1. Regarding the soybean crop, in doses from 245 g sulfentrazone + 490 g diuron a.i. ha-1 there was a greater number of pods per plant and higher grain yield, of about 3,000 kg ha-1. The application of herbicides led to a transient inhibition of PSII activity, which did not result in a reduction in crop grain yield, indicating plant recovery. Therefore, the mixture of sulfentrazone + diuron is a good alternative for the weed management in pre-emergence of soybean, and should be positioned according to the history of field infestation. [ABSTRACT FROM AUTHOR]

Diuron [3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea] is a substituted urea herbicide, carcinogenic for the rat urinary bladder. It has been hypothesized that Diuron cytotoxicity, resulting in regenerative proliferation, leads to urothelial hyperplasia and, finally, to bladder tumors, but molecular mechanisms of carcinogenesis have not still fully investigated. Here, we report the results of a study aimed at verifying the involvement of BAG3, an intracellular protein expressed in several tumors, in the Diuron‐induced carcinogenesis. For this purpose, we analyzed the effect of Diuron on human primary urothelial cells and on human dermal fibroblasts. We found that while high concentrations of Diuron have a cytotoxic effect in human primary urothelial cells, in the same cells, noncytotoxic concentrations of the herbicide induce BAG3 expression. These findings show that BAG3 is a molecular target of Diuron and unravel the possible involvement of BAG3 protein in bladder carcinogenesis induced by the herbicide. In addition, these results suggest that BAG3 might be a potential early biomarker of damage induced by chronic exposure to Diuron. [ABSTRACT FROM AUTHOR]

Two field experiments were conducted at the Research Farm of the Ibrahim Badamasi Babangida University, Lapai, Niger State during the 2018 and 2019 rainy seasons to determine the effect of neem fertilizer rates and weed control methods on the growth and yields of soybeans. The experimental treatments were made up of four neem fertilizer rates (0, 50, 100 and 150 kg ha-1) and six weed control methods (pendimethalin at 1.5 kg a.i ha-1 followed by one hoe weeding, pendimethalin at 2.0 kg a.i. ha-1 followed by diuron at 1.5 kg a.i ha-1, weeding once at 3 WAS, weeding twice at 3 and 6 WAS, weed free and weedy check. The experiment was a 3 × 3 factorial experiment laid out in a Randomize complete block design replicated three times. TGX 1448 - 2E variety of soybean was used for the study. Result showed that weed control efficiency was better with the use of 150 kg ha-1 of neem fertilizer, while decrease in weed dry matter was obtained at 50 kg ha-1. Increase in number of leaves and leaf area were encouraged with 150 kg ha-1 of neem fertilizer. Weed free treatments recorded the highest grain yield and 100 seed weight of soybean. Pendimethalin at 1.5 or 2.0 kg a.i ha-1 supplemented with one hoe weeding or diuron at 1.5 kg a.i ha-1respectively can be an alternative for better control of weeds to obtain greater yield of soybean in the study area. [ABSTRACT FROM AUTHOR]

Although more and more precise and efficient methods of scientific research regularly arise, inhibitory analysis still remains far from being the least among the extensively used experimental approaches. Many current investigations aplly chemical inhibitors of photosystem II as instruments of scientific cognition. Novel chemical inhibitors are being screened, educed, and/or designed. New effects of the already known inhibitors are being discovered and/or significantly corrected. The review presents the generalized information on both the known inhibitors, such as diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea), dinoseb (6‑sec-butyl-2,4-dinitrophenol), and ADRY agents (agents causing Acceleration of the Deactivation Reactions of the water-splitting enzyme system Y) and recently revealed chemical inhibitors of PSII (derivatives of perfluoroisopropyldinitrobenzene and metal-organic complexes). The action of carbonic anhydrase inhibitors on a photochemical activity of PSII is also discussed. [ABSTRACT FROM AUTHOR]

Sugarcane is a major crop in Brazil as well as other tropical areas. The rise of green cane systems that maintain straw on the soil surface after mechanical harvesting alongside extreme precipitation has changed the use and environmental fate of pesticides, mainly herbicides. The goal of this research was to evaluate the effects of straw amounts (0, 7, and 14 t ha−1), soil water contents (10 and 18%, volumetric basis), and herbicide incubation time (0 and 3 days) on the runoff of hexazinone and diuron in green cane systems, under a heavy rainfall event of 120 mm that is becoming more frequent over the decades in tropical areas. A rainfall event of 80 mm h−1 during 1.5 h was simulated over a 1 m2 area, using a rainfall simulator with a structure designed to collect runoff. Herbicides in water runoff were determined by ultra performance liquid chromatography with mass spectrometry (UPLC ESI QTOF/MS), while herbicides attached to sediments were estimated using Kd values. Sugarcane straw on the soil surface decreased water, sediments, and diuron runoffs, but barely affected hexazinone losses. Crop residues cannot prevent runoff of highly soluble molecules, such as hexazinone. Herbicides' runoffs were much higher in the aqueous phase and at higher soil moisture content. Maintaining 7 t ha−1 of sugarcane straw on the soil surface was enough to mitigate water, sediments, and diuron runoff, but 3-day herbicide incubation did not affect both herbicides runoffs. Diuron and hexazinone are heavily used herbicides that can reach concerning concentrations in the runoff and contaminate surface waters in vulnerable areas if no control measures are taken. [ABSTRACT FROM AUTHOR]

In this work, the adsorption-desorption dynamics of diuron in three typical Kenyan agricultural soils, Nzoia (NZ), Thika (TH) and Machakos (MK) was investigated. The equilibrium adsorption data, tested against three classical nonlinear adsorption isotherms, was best described by the Freundlich model. The Freundlich adsorption constant, (KF), increased in the order MK > TH > NZ soil. Additionally, the negative Gibb's free energy values indicate the adsorption processes were thermodynamically spontaneous and physical. Multiple linear regression analysis indicated that the adsorption-desorption behavior was controlled by the clay and phosphorus contents of the soil. Phosphorus negatively affected the adsorption of diuron and promoted desorption. The groundwater ubiquity score (GUS) indicated that diuron movement rating in MK soil was ‘moderate’ while the movement in TH and NZ soils was ‘high’.

Given the essential role of arbuscular mycorrhizal fungi (AMF) in soil systems and agriculture, their use as biological indicators has risen in all fields of microbiology research. However, AMF sensitivity to chemical pesticides is poorly understood in field conditions, and not explored in ecotoxicology protocols. Hence, the goal of this study was to evaluate the effects of different concentrations of glyphosate (Roundup®) and diuron+paraquat (Gramocil®) on the germination of spores of Gigaspora albida and Rhizophagus clarus in a tropical artificial soil. This study was conducted in 2019 at the Soil Ecology and Ecotoxicology Laboratory of the Universidade do Estado de Santa Catarina. The nominal concentrations of glyphosate were 0, 10, 50, 100, 250, 500, 750 and 1000 mg a.i. kg−1. For diuron+paraquat, the concentrations tested were 0, 10 + 20, 50 + 100, 100 + 200, 250 + 500, 500 + 1000, 750 + 1500 and 1000 + 2000 mg a.i. kg−1. Glyphosate did not alter germination of G. albida, but germination inhibition of R. clarus spores was of 30.8% at 1000 mg kg−1. Diuron+paraquat inhibited by 8.0% germination of G. albida, but only at the highest concentration tested. On the other hand, effects on R. clarus were detected at 50 + 100 mg kg−1 concentration and above, and inhibition was as high as 57.7% at the highest concentration evaluated. These results suggest distinct response mechanisms of Rhizophagus and Gigaspora when exposed to herbicides, with the former being more sensitive than the later.

Tedera is a drought-tolerant perennial forage legume introduced in Australia in 2006. In October 2018, T15-1218 Lanza®, the world’s first tedera variety, was released by the Department of Primary Industries and Regional Development and Meat & Livestock Australia for commercial use. A key agronomic practise for the successful establishment and adoption of tedera is to have a robust herbicide package to control a range of grass and broadleaf weeds well tolerated by tedera. A total of 9 pre-emergent and 44 post-emergent herbicide treatments were evaluated in eight experiments from 2017 to 2021. To control grasses such as annual ryegrass (Lolium rigidum Gaud.), propyzamide and carbetamide can be recommended for pre- or post-emergent applications and butroxydim, clethodim, and haloxyfop for post-emergent applications. The broadleaf pre-emergent herbicides recommended are clopyralid to control emerged capeweed (Arctotheca calendula (L.) Levyns), fomesafen to control pre-emergent wild radish (Raphanus raphanistrum L.), and the double mix of fomesafen + diuron, flumetsulam + diuron, and the triple mix of fomesafen + diuron + flumetsulam to control pre-emergent capeweed, pre- and post-emergent wild radish, and other broadleaf weeds. The most consistently well tolerated post-emergent herbicides by tedera seedlings and adult plants were diflufenican, diuron, flumetsulam, fomesafen, and their two- or three-way mixes that will provide good control of capeweed and wild radish. Desiccants such as paraquat or diquat were also well tolerated by 1-year-old tedera plants that recovered after being desiccated.

Recently, research has contributed to better knowledge on the occurrence of pesticides in coastal water by identifying frequently detected substances, their concentration range and their acute and chronic toxicity for organisms. Pesticide pollution is of particular concern in France due to important agricultural activities and presence of several exoreic catchment areas that vehicle pesticides up to coastal waters, impacting non-target marine species. Several ecotoxicology questions remain to be addressed concerning the long-term effects of chronic pesticide exposure and the mechanisms involved in adaptation to chemical stress. In the present study, we brought new insights on the genetic and epigenetic effects of the herbicide diuron in oyster genitors. During gametogenesis, we exposed Crassostrea gigas to environmentally realistic herbicide concentrations (0.2–0.3 μg L−1 during two 7-day periods at half-course and end of gametogenesis). Diuron exposure was shown to decrease global DNA methylation and total methyltransferase activity in whole oyster tissue; this is consistent with the previous observation of a significant decrease in DNMT1 gene expression. Diuron effect seemed to be tissue-specific; hypermethylation was detected in the digestive gland, whereas diuron exposure had no effect on gill and gonad tissue. The genotoxicity of diuron was confirmed by the detection of one adduct in gonad DNA. By using in vitro approaches and human DNMT1 (DNMT1 has not been purified yet in bivalves), the presence of DNA lesions (adduct, 8-oxodGuo) was shown to interfere with DNMT1 activity, indicating a complex interaction between DNA damage and DNA methylation. Based on our results, we propose mechanisms to explain the effect of diuron exposure on DNA methylation, a widespread epigenetic mark. [ABSTRACT FROM AUTHOR]

Agriculture within the Great Barrier Reef catchment area has contributed to pesticide contamination of adjacent freshwater ecosystems that flow into the Great Barrier Reef World Heritage Area. A novel multispecies toxicity test was used to assess the toxicity of diuron and hexazinone, 2 herbicides commonly detected within the Great Barrier Reef catchment area, to a community of 3 tropical freshwater microalgae: Monoraphidium arcuatum, Nannochloropsis‐like sp., and Pediastrum duplex. Diuron was the most toxic herbicide, with 10% inhibition concentration (IC10) values of 4.3, 7.1, and 29 µg/L for P. duplex, M. arcuatum, and Nannochloropsis‐like sp., respectively, followed by hexazinone, with IC10 values of 15, 18, and 450 µg/L, respectively Toxicity testing on 2 commercial formulations (Barrage, 13.2% hexazinone and 48.6% diuron; Diurex, 90% diuron) showed that additives in the commercial formulations did not significantly increase the toxicity of diuron. Direct toxicity assessments were carried out on water samples from the herbicide‐contaminated Sandy Creek, which discharges to the Great Barrier Reef lagoon, and a clean reference site, Tully Gorge in the Tully River. Toxicity was observed in several Sandy Creek samples. Artificial herbicide mixtures were assessed in synthetic soft water and natural freshwaters, with toxic responses being observed at environmentally relevant concentrations. The present study successfully applied a novel multispecies tropical microalgal toxicity test, indicating that it is an effective tool for the assessment of herbicide toxicity in both natural and synthetic freshwaters. Environ Toxicol Chem 2021;40:473–486. © 2020 SETAC [ABSTRACT FROM AUTHOR]

Photosystem II (PSII) is one of the main pigment-protein complexes of photosynthesis which is highly sensitive to unfavorable environmental factors. The heterogeneity of PSII properties is essential for the resistance of autotrophic organisms to stress factors. Assessment of the PSII heterogeneity may be used in environmental monitoring for on-line detection of contamination of the environment. We propose an approach to assess PSII oxygen-evolving complex and light-harvesting antenna heterogeneity that is based on mathematical modeling of the shape of chlorophyll a fluorescence rise of 3-(3,4-dichlorophenyl)-1,1-dimethylurea-treated samples. The hierarchy of characteristic times of the processes considered in the model makes it possible to reduce the model to a system of three ordinary differential equations. The analytic solution of the reduced three-state model is expressed as a sum of two exponential functions, and it exactly reproduces the solution of the complete system within the time range from microseconds to hundreds of milliseconds. The combination of several such models for reaction centers with different properties made it possible to use it as an instrument to study PSII heterogeneity. PSII heterogeneity was studied for Chlamydomonas at different intensities of actinic light, for Scenedesmus under short-term heating, and for Chlorella grown in nitrate-enriched and nitrate-depleted media., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Diuron is a selective and the most persistent herbicide. Widespread use of this compound has led to the elevated concentrations of diuron in groundwater and wastewater. The main objectives of this study were to investigate biodegradation of diuron by Pseudomonas aeruginosa FN and evolved degradation product, 3,4‐dichloroanilines (3,4‐DCA). The influence of temperature, initial optical density of Pseudomonas aeruginosa FN and initial diuron concentration were examined to further optimize biodegradation of diuron, and the effect of these factors were investigated by the response surface methodology (RSM) and full factorial design (FFD). The optimal biodegradation conditions were obtained at T = 25°C, γ (diuron) = 0.5 mg/L and initial optical density of 0.2. The biodegradation kinetic of diuron was described by Monod model and the obtained value of F‐test was grater that 0.96 which showed good correlation between Monod model and experimental results. [ABSTRACT FROM AUTHOR]

A new synthetisis method of Cu-doped ZnO nanoparticles is presented in this work, this novel approach allow one to produce Zinc oxide nanocristal owing to a modified Polyol process that makes use of triethyleneglycol (TREG) as a solvent. The structure and morphology of the nanoparticles were characterized by high-resolution transmission electron microscopy (HRTEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), N2 adsorption study, UV-Vis diffuse reflectance spectroscopy, inductively coupled plasma optical emission spectroscopy and Raman spectroscopy. The lightly doped Zn1-xCuxO photocatalysts consisted in a novel nanorods structure of Zn0.9990Cu0.0010O nanoparticles. Taking the photocatalytic degradation of diuron under solar light as liquid phase test reaction, the lightly doped Zn0.9990Cu0.0010O nanorods photocatalysts showed strongly enhanced photocatalytic activity when compared to the bare ZnO counterpart. The apparent rate constant value of Zn0.9990Cu0.0010O was 22 times higher than that of pure ZnO. In order to study the environmental risk of Cu-ZnO, clams Ruditapes decussatus were exposed to Cu-ZnOC1 = 0.5 mg/L, Cu-ZnOC2 = 1 mg/L and Cu-ZnO C3 = 5 mg/L. Catalase (CAT) activities, malondialdehyde (MDA) content and acetylcholinesterase (AChE) activity were determined in gills and digestive gland of treated and untreated clams. Thus, no significant effects were detected in the gills of exposed clams after 7 days compared to control. Thus, MDA level and CAT activity showed significant differences in digestive glands of groups treated by the highest concentration of Cu-ZnO NPs compared to the control. No adverse effects on AChE activity was detected after Cu-ZnO NPs exposure. These results demonstrated that, although Cu-ZnO NPs is not acutely toxic to Ruditapes decussatus, it does exert oxidative stress on clams. These results are encouraging for the Cu-ZnO NPs use in variety of applications due to its high photocatalytic and low environmental toxicity. [ABSTRACT FROM AUTHOR]

Lignocellulosic agricultural residues are worldwide used for the production of activated carbons with purpose of eliminate a large range of pollutants such as diuron, a very persistent herbicide found in streams. This work studies the adsorption of diuron in aqueous solution on two different activated carbons, a commercial activated carbon and a prepared one. Activated carbon has been produced from seed hulls of baobab (Andansonia digitata), as a valorization pathway for this waste. Precursors have been impregnated with potassium hydroxide and then carbonized under nitrogen flow. The porous structure of the carbon has been determined by methylen blue adsorption, iodine adsorption and nitrogen adsorption-desorption. The BET surface areas of the produced carbon was 1086 m2·g‒1 with an iodine and methylene blue values of 1854.2 mg·g−1 and 26.66 mg·g−1 respectively. Batch removal kinetics of diuron has been studied at 5, 13 and 20 ppm initial concentrations on the two activated carbons in a reconstituate solution. The results showed that adsorption of diuron can be modelled by Langmuir isotherm with a maximal adsorption capacity of 65.7 mg·g−1 for baobab carbon and 151.8 mg·g−1 for commercial activated carbon at 120 min equilibrium time. Speudo-second order reaction fits well with data collected during adsorption of diuron on carbons studied. Thus, Baobab seed hulls can be considered as good precursors for preparation of activated carbon with high specific surface area.

In this study, the comparative effect of TeA, DCMU, bentazone, DBMIB and MV on prompt fluorescence and the MR 820 signal was simultaneously analyzed to provide an insight into how to elucidate their precise influence on Ageratina adenophora photosystems. The herbicides that interrupt electron transport beyond Q A , such as TeA, DCMU and bentazone, mainly increased the J-step level of fluorescence rise kinetics as a result of accumulation of Q A −, but showed differences in detail. The IP phase disappeared in the presence of DCMU and bentazone with a significant increase in F O value. TeA treatment retained the IP phase with lowering F M. As an inhibitor of plastoquinone re-oxidation, DBMIB increased the I-step (IP phase almost unnoticable) without changing F O and F M values. MV blocking PSI electron transfer through intercepting electrons from the FeS clusters suppressed the IP phase by decreasing the P level. Considering the W IP kinetics, TeA and DBMIB also affected PSI activity. After DCMU and MV treatment, the major change in the MR 820 kinetics was the loss of the slow phase due to the complete prevention of electron movement from PSII to re-reduce PC+ and P 700 +. TeA, bentazone and DBMIB clearly suppressed the MR 820 slow phase and decreased the re-reduction rate of PC+ and P 700 + (V red), significantly. However, there were still parts of electrons being donated to PC+ and P 700 +, showing a smaller slow phase and PC+ and P 700 + re-reduction rate. Additionally, TeA and DBMIB also somewhat declined the fast phase and PC and P 700 oxidation rate (V ox). Image 1 • Precise effect of five compounds on photosynthesis can be distinguished by PF and MR 820 signal. • TeA, DCMU and bentazone increased mainly the J-step because of inhibiting electron flow beyond Q A. • DBMIB made a smaller IP amplitude for blocking re-oxidation of PQ by binding to cyt b 6f. • DCMU and MV led to the loss of MR slow phase due to preventing re-reduction of PC+ and P 700 +. • TeA, bentazone and DBMIB suppressed the re-reduction rate of PC+ and P 700 +. [ABSTRACT FROM AUTHOR]

Diuron is one of the major hazardous pollutants which posses severe risk to the environment and human healthiness. On the other hand, salinity is the most severe environmental stressor that limits crop productivity. Therefore, it is required to address this co-existing abiotic stresses in agricultural soil. Plant growth–promoting rhizobacteria have gained an engaging role in the degradation of pesticides in agricultural soil. However, their role against the restoration of diuron-contaminated saline soil is still not known. Thus, in this study, diuron-degrading, salinity-tolerant Stenotrophomonas rhizophila strain CASB3 was isolated and characterized. Strain CASB3 showed important PGP traits under normal and diuron or salt stresses. Complete degradation of 10–50 mg L−1 diuron in the aqueous medium under normal and salinity stress conditions was achieved within 48–120 h and 48–192 h, respectively. A unique pathway for diuron biodegradation was proposed based on GC-MS analysis. In a greenhouse study, CASB3 inoculated into diuron-contaminated saline soil efficiently degraded diuron (50 mg kg−1) by 94% in 42 days and simultaneously resulted in an enhancement of root-shoot length (47.22–63.41%), fresh-dry biomass (136.36–156.66%), and photosynthetic pigments (36.93–92.28%) in Lactuca sativa plants. These results suggest the strain CASB3 could be used as a bioresource for the reclamation of diuron-contaminated saline soils. [ABSTRACT FROM AUTHOR]

The glyphosate-resistant Eleusine indica (GR-ESU) case has dominated at oil palm plantations in North Sumatra Province, Indonesia and will increase evolution into resistance. This research was aimed to determine the role of Monosodium Methyl Arsenate (MSMA)+diuron to control the agronomic characteristics of GR-ESU biotypes. This research was conducted in the Weed Research Center Land, Faculty of Agriculture, Universitas Sumatera Utara in November 2017 until August 2018. This research used Randomized Block Design non-factorial with factor GR-ESU biotypes that were sprayed with glyphosate at the dose of 3 l.ha-1, and MSMA+diuron at the dose of 5 l.ha-1 within four replications. The parameters were analyzed using one-way ANOVA and were continued by DMRT at P < 0.05 with IBM SPSS Statistics v.20 software. The results showed that a decrease in the survival of GR-ESU at the changes from glyphosate to MSMA+diuron. The GR-ESU on MSMA+diuron showed leaf color changes (leaf green loss/chlorosis) at 3 until 21 days after sprayed. The ability of MSMA+diuron had completely (100%) controlled within 18 of 29 GR-ESU biotypes and had effectively controlled the tillers, flowering, fresh- and dry weight in GR-ESU biotypes of 87.53%; 66.88%; 95.66%; and 95.92% respectively compared to glyphosate. The use of MSMA+diuron as a different mode of action herbicide is highly recommended to control GR-ESU biotypes at oil palm estate. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the effect of different herbicide treatments on moisture removal and calorific power of biomass sorghum for co-generation of electric energy through burning. The experiment was conducted in randomized complete block design with four replicates per treatment and a 6x4 factorial scheme (six herbicide treatments x four intervals between spraying and harvesting). The herbicide treatments were: two different doses of glyphosate (1.92 kg a.i. ha-1 and 3.84 Kg a.i. ha-1), paraquat (0.4 Kg a.i. ha-1), a commercial mixture of paraquat + diuron (0.6 + 0.3 Kg a.i. ha-1), glufosinate-ammonium (0.8 Kg a.i. ha-1) and control (unsprayed). The intervals between spraying and harvesting assessed were 7, 14, 21 and 28 days after desiccation (DAD). It was assessed: the number of leaves per plant, moisture content of leaves, panicles, culm and whole ground plants and Superior Calorific Power (SCP). The herbicides paraquat and paraquat + diuron promotes defoliation, after 14 DAD. Glyphosate, paraquat, paraquat + diuron and glufosinateammonium reduce leaf and panicle moisture, despite only glyphosate reduces moisture in the culm. The herbicides do not affect the SCP of biomass sorghum. Therefore, the herbicides, especially glyphosate, have high potential for preharvest desiccation in biomass sorghum. [ABSTRACT FROM AUTHOR]

Adsorption of organic pollutants (OPs), bisphenol A, and diuron, from aqueous solutions onto porous carbon materials (CMs) prepared from olive kernels, have been investigated. The effects of initial pH, initial OP concentration, temperature, and contact time on the adsorption capacity were studied. The adsorption of bisphenol A and diuron onto CMs was found to be optimal at pH 5.6 and 6.9, respectively. It was noticed that the adsorption of those organic pollutants from aqueous solution declined with increasing temperature and the process is exothermic. The rate of adsorption followed the second order kinetic equation. The equilibrium results showed that Langmuir model fits well with the data. The maximum adsorption capacities obtained using the best CM were 476 and 434 mg g−1 for BPA and diuron, respectively. The results showed that CMs made from olive kernels are an excellent and inexpensive biomass waste–derived sorbent. [ABSTRACT FROM AUTHOR]

Energy dynamics of the weed control options adopted in rainfed cotton was valuated in a study conducted at College farm, PJTSAU, Hyderabad, Telangana State during kharif, 2017 in red and black soils. Three doses of Diuron (0.5, 0.75 and 1.0 kg ha-1), pendimethalin 38.7% CS at 677 g ha-1 as PE followed by sequential application of pyrithiobac sodium 10% EC 62.5 g ha-1 + quizalofop p ethyl 5% EC 50 g ha-1, intercropping of cotton with green manure crop (Sunhemp), mechanical weeding thrice at 20, 40 and 60 DAS (weed free), polymulch and unweeded control were the treatments included in RBD design which was replicated thrice. The energy balance studies were determined by using direct and indirect energy. The results indicated that the maximum energy input was required for polymulch in both the soils. Highest kapas energy output (EOk) was observed in polymulch and mechanical weeding which was followed by diuron 1.0 kg ha-1 PE fb pyrithiobac sodium + quizalofop p ethyl PoEin red soil, whereas in black soils, diuron 0.75 kg ha-1 PE fb pyrithiobac sodium + quizalofop p ethyl PoE followed polymulch and mechanical weeding treatments. EUE of both kapas and total output was significantly higher in diuron 1.0 kg ha-1 PE fb pyrithiobac sodium + quizalofop p ethyl PoE in red soil. While in black soil, significantly highest EUE of kapas and total output was recorded in diuron 0.75 kg ha-1 PE fb pyrithiobac sodium + quizalofop p ethyl PoE. [ABSTRACT FROM AUTHOR]

Introduction: Pesticide use in Brazil is widespread. General population is concerned about the risks of consuming food containing pesticide residues. Objective: The greatest contribution of this work is to highlight the absence of blood residual contamination in the population of medium plant of Rio Grande do Sul, Brazil, by the pesticides: atrazine, abamectin, chlorpyriphos and diuron. Materials and methods: Pesticide residues were extracted using QuEChERS approach and were quantified by liquid chromatography-mass spectrometry. Results: Most volunteers (92.75%) present normal levels of plasma cholinesterase and all volunteers do not present residues of any pesticide tested. Conclusion: This study demonstrates that even though the use of pesticides is widespread in our region, the population did not present blood residues or enzymatic changes suggestive of acute intoxication.. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Bioprocess Engineering is the property of Chinese Journal of Bioprocess Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study was to identify and quantify herbicide residues in water samples of rain, cisterns, streams, ponds, springs, semi-artesian wells, dams and a river in the Rio Samambaia sub-basin in the Federal District and eastern Goiás. A total of 287 samples were collected from 20 farms in the sub-basin in the rainy (February, summer) and dry (August, winter) seasons in 2016. Aminomethylphosphonic acid (AMPA, a glyphosate metabolite), clethodim, chlorimuron-ethyl, diuron, fluazifop acid (a fluazifop-p-butyl metabolite and the active ingredient), haloxyfop acid (a haloxyfop-methyl metabolite and the active ingredient), imazamox, mesotrione, metsulfuron, nicosulfuron and pendimethalin were not identified in any water sample. In the rainy season, approximately 99% of the samples contained residues at least one of the evaluated herbicides; in the dry season (, 100% of the samples contained residues of at least one of the evaluated herbicides. When considering only detection frequency, metribuzin, atrazine, clomazone and haloxyfop-methyl were the main herbicides found in the water of the Samambaia River sub-basin. In turn, based on levels higher than the limit of quantification, the main compounds detected were atrazine, clomazone, haloxyfop-methyl and glyphosate. In both seasons, the highest relative concentrations of herbicides for the rainy and dry seasons were found in spring water, 25% and 56%, respectively, and dam water, 23% and 16%, respectively. [ABSTRACT FROM AUTHOR]

The study was conducted for exploring the effect of Dropp ultra and Ethrel, their application rates and time of application on two American cotton cultivars. The experiment was carried out at Regional Agricultural Research Station, Nandyal with cultivars NH615 and Sivanandi for two consecutive seasons from 2015-2017 in split plot design with three replications. Application of defoliants like Dropp ultra SC (Thidiazuron 360 + Diuron 180) 200 and 250 ml/ha, Ethrel 1500, 2000 and 3000 ppm were carried at 120 and 140 days after sowing respectively. The results of the study indicated that defoliation with Dropp ultra 250 ml/ha recorded higher percentage of defoliation (92.3) and higher seed cotton yield (2207 kg/ha). Application of defoliants at 140 days after sowing significantly recorded higher yields. There was no difference between the treatments in terms of fibre length and fibre strength. However fibre fineness and uniformity ratio were significantly affected by application of defoliants. [ABSTRACT FROM AUTHOR]

Copyright of Asian Journals of Ecotoxicology is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: This study investigated the toxicological aspects of chlorpyrifos and diuron concentrations below maximum residue limit (MRL) in rabbits, determined their residues associated with the toxicological aspects and modeled the toxicity. Methods: Single- and repeated-dose toxicity tests were employed using white rabbits as experimental animals. In both toxicity tests, rabbit responses were evaluated by monitoring their body weight, various growth factors, activity of acetylcholinesterase (AChE), and activities of liver enzymes, alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Various kidney functions (urea, uric acid, creatinine and total protein concentration) were evaluated. Pesticide residues were also determined by GC. Results: Repeated-dose toxicity test of chlorpyrifos and diuron significantly reduced the body, liver and heart weights compared with those of the control group (p = 0.045). Both tests reduced the serum AChE, AST and ALT activities and increased ALP activity. On the other hand, the tested compounds increased the uric acid and urea concentrations and reduced the creatinine concentration in the blood serum. Chlorpyrifos was detected in blood, kidney and manure samples whereas diuron was detected in liver tissues and blood samples. Conclusions: Concentrations of chlorpyrifos and diuron far below MRL values generated various toxic effects in rabbits, indicating a possible health risk. [ABSTRACT FROM AUTHOR]

Herbicide contamination of nearshore tropical marine ecosystems is widespread and persistent; however, risks posed by most 'alternative' herbicides to tropical marine microalgae remain poorly understood. Experimental exposures of the important but understudied microalgae Rhodomonas salina to seven individual Photosystem II (PSII) inhibitor herbicides (diuron, metribuzin, hexazinone, tebuthiuron, bromacil, simazine, propazine) led to inhibition of effective quantum yield (ΔF/Fm′) and subsequent reductions in specific growth rates (SGR). The concentrations which reduced ΔF/Fm′ by 50% (EC50) ranged from 1.71-59.2 µg L−1, while the EC50s for SGR were 4-times higher, ranging from 6.27-188 µg L−1. Inhibition of ΔF/Fm′ indicated reduced photosynthetic capacity, and this correlated linearly with reduced SGR (R2 = 0.89), supporting the application of ∆F/Fm' inhibition as a robust and sensitive indicator of sub-lethal toxicity of PSII inhibitors for this microalga. The three non-PSII inhibitor herbicides (imazapic, haloxyfop and 2,4-Dichlorophenoxyacetic acid (2,4-D)) caused low or no toxic responses to the function of the PSII or growth at the highest concentrations tested suggesting these herbicides pose little risk to R. salina. This study highlights the suitability of including R. salina in future species sensitivity distributions (SSDs) to support water quality guideline development for the management of herbicide contamination in tropical marine ecosystems. [ABSTRACT FROM AUTHOR]

After designing and constructing an electrochemical reactor with concentric electrodes and tangential feed (RECT), it is necessary to characterize it and to study its performance. The experimental study of the residence time distribution (RTD) was conducted for flow rates of 2.78 × 10–6 m3 s–1, 8.33 × 10–6 m3 s–1 and 13.9 × 10–6 m3 s–1. According to the values obtained from the Pe number (0.67–1.52), the RECT fits as tubular with great dispersion. The determined empirical correlation (Sh = 18.16 Re0.50 Sc0.33) showed a laminar flow behavior in the range of Reynolds number (Re) between 23 and 117. In order to use RECT in effluent treatment, an electrochemical oxidation study of the Diuron model molecule (Nortox®) was performed to analyze reactor performance in a closed system with total reflux. A decay kinetics of pseudo-first order was associated with the decay of the concentration of diuron and 30% mineralization in 180 min of process were obtained, having a total volume of 4 × 10–3 m3 and an initial concentration of commercial Diuron in 215.83 mg dm–3. Eleven by-products were identified by HPLC–MS analysis and, from this, it was possible to propose a route of degradation of the diuron. From these observations, it can be inferred that the studied electrochemical reactor had applicability in the degradation of recalcitrant compounds, as is the case of commercial diuron. Make some changes in the electrochemical reactor studied and other advanced oxidative processes, such as electro-Fenton, can be associated with the studied system to achieve a better conversion efficiency. [ABSTRACT FROM AUTHOR]

Diuron is a phenyl urea herbicide used to control weeds in agricultural lands. The degradation of diuron in the atmosphere takes place dominantly via reaction with OH radicals. In this work, the OH addition reaction of diuron has been studied by using density functional theory methods M06-2X, ωB97X-D and MPWB1K with 6-31G(d,p) basis set. The calculated thermochemical parameters show that OH addition reaction occurs favourably at C2 position of diuron. The rate constant is calculated for the favourable initial reaction pathway by using canonical variational transition state theory with small curvature tunnelling (SCT) correction over the temperature range of 200–1000 K. The reaction of initially formed diuron-OH adduct intermediate with O2 leads to the formation of peroxy radical intermediate. The reaction of peroxy radical intermediate with HO2 and NOx (x = 1, 2) radicals is studied in detail. The results obtained from time-dependent density functional theory (TDDFT) calculations show that the intermediates and products formed from oxidation of diuron can be easily photolyzed in the sunlight. This study provides thermodynamical and kinetic data for the atmospheric oxidation of diuron by OH radical addition reaction and demonstrates the atmospheric chemistry of diuron and its derivatives. [ABSTRACT FROM AUTHOR]

Sugar industry is important to Fiji's economy as it contributes 1.1% of GDP. Sugarcane is cultivated as an intensive mono-cropping in Fiji, inorganic fertilizer and herbicides were commonly used. This survey was conducted to evaluate the present status of herbicide and inorganic fertilizer application to sugarcane and assessed the farmer's knowledge and perceptions. As well, this survey evaluated present socioeconomic status of sugarcane farmers. Results revealed that average Fiji sugarcane farm land size was 11.5 acers (4.6 hectares). Diuron (800-900g/kg Diuron), Amine (720g/L 2,4-D Dimethyl Amine Salt) and Glyphosate (Glyphosate isopropyl amine salts) were the most popular herbicide. The 30% of farmers used Glyphosate together with Amine and Diuron. Most farmer (>80%) were aware about correct application dosage and 81% of farmers use protective equipment during application. Labasa sugarcane farmers used more herbicide and chemical fertilizer than other areas. Most sugarcane farmlands become infertile due long-term use for intensive mono-cropping. At present most farmers heavily depend on inorganic fertilizer. Almost all farmers who participated to this survey aware of environment and health effect of herbicide and chemical fertilizer. The 78% farmers pass 40 years' age and most of them were not happy about sugarcane farming due its less profit in comparison to past. Therefore, currently, very few selected farmers are farming sugarcane as their livelihood profession. [ABSTRACT FROM AUTHOR]

Hydrochar derived from Argan nut shell (ANS) was synthesized and applied to remove bisphenol A (BPA) and diuron. The results indicated that the hydrochar prepared at 200 °C (HTC@ANS-200) possessed a higher specific surface area (42 m2/g) than hydrochar (HTC@ANS-180) prepared at 180 °C (17 m2/g). The hydrochars exhibited spherical particles, which are rich in functional groups. The HTC@ANS-200 exhibited high adsorption efficiency, of about 92% of the BPA removal and 95% of diuron removal. The maximum Langmuir adsorption capacities of HTC@ANS-200 at room temperature were 1162.79 mg/for Bisphenol A and 833.33 mg/g for diuron (higher than most reported adsorbents). The adsorption process was spontaneous (− ΔG°) and exothermic (− ΔH°). Excellent reusability was reclaimed after five cycles, the removal efficiency showed a weak decrease of 4% for BPA and 1% for diuron. The analysis of Fourier transforms infrared spectrometry demonstrated that the aromatic C=C and OH played major roles in the adsorption mechanisms of BPA and diuron in this study. The high adsorption capacity was attributed to the beneficial porosity (The pore size of HTC@ANS-200 bigger than the size of BPA and diuron molecule) and surface functional groups. BPA and diuron adsorption occurred also via multiple adsorption mechanisms, including pore filling, π–π interactions, and hydrogen bonding interactions on HTC@ANS-200. [ABSTRACT FROM AUTHOR]

Variations of temperature and photoperiod throughout different seasons can affect aquatic communities such as biofilms. Biofilms, generally present at the base of trophic chains in freshwaters, are also subject to organic contamination, and are especially affected by herbicides. Many studies have investigated the effect and interactions of herbicides and environmental factors on biofilms, but never with a toxicokinetic point of view. The objective of this study was to assess structural and functional changes in biofilms exposed to diuron, and to link them with contaminant accumulation, under the influence of temperature and light variations. To this aim, biofilms were exposed to all possible combinations of three concentrations (0, 5 and 50 µg L−1) of diuron, two temperatures (10 and 26 °C), and two light/dark photoperiods (16/8, 10/14), for durations of 0, 1 and 3 days. Diuron accumulation in biofilms was quantified and structural descriptors (protein and polysaccharide contents, dry weight) and functional endpoints (photosynthetic and enzymatic activities) were analyzed. The results obtained mainly highlighted the influence of temperature on diuron bioaccumulation and the associated toxic impact on biofilms. Bioaccumulation in biofilms exposed during three days at 10 °C, at the highest diuron concentration, was in average 1.4 times higher than bioaccumulation on biofilms exposed to 26 °C. Accordingly, the photosynthetic yield was more inhibited at lower than at higher temperatures. Temperature was also the highest impacting factor for metabolism regulation; for example, at 26 °C after three days of exposure, polysaccharide production was boosted under both photoperiods tested. [ABSTRACT FROM AUTHOR]

The herbicide removal of Diuron in a fixed-bed column packed with the Moringa oleifera bark biosorbent was investigated experimentally and through phenomenological mathematical modelling. To understand the physical phenomena involved, the steps of external mass transfer resistance, internal mass transfer resistance and the adsorption phenomenon itself were considered as possible limiting steps in the herbicide mass transfer from the liquid to the solid phase. In the developing process of the internal mass transfer resistance model, two hypotheses were considered: constant mass transfer coefficient and mass transfer coefficient as a function of the herbicide concentration in the biosorbent. The experimental breakthrough curves were obtained for different flow rates and feed concentrations, in order to evaluate the model's predictive capacity. The mass transfer parameter values of the mathematical models were estimated using the simplex downhill optimization method. The model that considers the resistance a mass transfer internal with parameter Ks variable represented effectively the dynamic behaviour of the herbicide biosorption process in fixed-bed column, in the various evaluated conditions, indicating that this mechanism controls the biosorption process. Thus, the phenomenological mathematical modelling proved to be an analysis important tool, understanding and the herbicide adsorption systems design in a fixed-bed column. [ABSTRACT FROM AUTHOR]

Due to their abundance in nature, clays have been frequently studied in the adsorption of different emergent contaminants, since they have good efficiency and low cost. Therefore, the present study aimed to evaluate the performance of commercial organoclays as an adsorbent in the environmental remediation of wastewater containing the herbicide Diuron. The clay was characterized by the techniques of N2 physisorption, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and point of zero charge. In the batch adsorption experiments it was verified that the adsorption kinetics is ruled by the pseudo-second-order model (R2 > 0.97), and the adsorption equilibrium study at different temperatures (298, 302 and 308 K) showed that the non-linear models of Langmuir (R2 > 0.99) and Freundlich (R2 > 0.98) were those that present better adjustments to the experimental data. In addition, the adsorption capacity in monolayer (qmax) was 44.24 mg g−1, being higher or comparable to several works reported in the literature. As for the thermodynamic adsorption study, it was possible to infer that the process is spontaneous (ΔG°ads < 0) and endothermic (ΔH°ads = 71.58 kJ mol−1) in the temperature range studied. As far as the regeneration study was concerned, the maximum desorption capacity, 26.59 mg g−1, was obtained from the use of ethanol as eluent at 298 K. [ABSTRACT FROM AUTHOR]

Considering the need for new technologies for the removal of pesticides from the aqueous environment, the Moringa oleifera seed husks (h-MO) were investigated for the diuron adsorption from contaminated water at different temperatures and solute concentrations. The biosorbent used in this study was characterized by chemical, structural and textural analyses. The best experimental condition for the biosorption was determined by evaluating the mass of the biosorbent and the pH solution. We found a good adsorption capacity for the herbicide where the maximum adsorption capacity was 14.74 mg/g at pH 5 and 45°C. In addition, the adsorption process of diuron by the h-MO occurred spontaneously, in which, ΔG° values increased as the temperature increased, meaning that the process tends to a more energetically favourable process at higher temperatures. Both Langmuir and Sips isotherm models presented satisfactory adjustment at all temperatures and the pseudo-second-order model presented the best fit for the experimental results. The application of the intra-particle diffusion model showed that the adsorption process started instantaneously through the boundary layer of the adsorbent and that the pore diffusion step was a limiting step in the process. Finally, the capacity of the h-MO was compared with other adsorbents that had been used for diuron removal from contaminated where it was found that the adsorption capacity of the h-MO is much higher than other natural adsorbents. [ABSTRACT FROM AUTHOR]

Effect of ferric ions at concentrations typically found in natural waters (0.05 to 1.06 mg L−1) and low H2O2 concentrations (between 0.5 and 17.9 mg L−1) on simulated sunlight-induced (300 W m−2) photo-Fenton degradation at initial neutral pH (7.0) of amoxicillin and diuron in Milli-Q water was studied using an rotatable central composite experimental design 22 with a central and two axial points. H2O2 concentration was the parameter playing the key role on the degradation of both pollutants. Despite that initial pH was 7.0 in Milli-Q water, this latter decreased rapidly in the first minutes, reaching values of 3.5 and 5.0 for diuron and amoxicillin respectively after 15 min of simulated sunlight irradiation. In contrast, in presence of bicarbonate/carbonate (HCO3−/CO3=), fluoride (F−), and humic acids (HAs) at concentrations found often in surface and well waters with ferric ion and H2O2 concentrations of 0.3 and 9.7 and 15.2 mg L−1 respectively, both pollutants exhibited a strong degradation keeping the circumneutral pH. Amoxicillin and diuron degradation byproducts found by HPLC/MS were compatible with HO• and/or CO3–• radical attack. Several photo-induced processes such as photo-Fenton (by dissolved ferric-HA complexes), heterogeneous photocatalysis (by colloidal iron), UV-B H2O2 photolysis, irradiated-dissolved organic matter, and their reactions with pollutants would be the main oxidative route responsible of degradations. These findings demonstrated that it could be possible using iron concentrations often found in natural waters to oxidize via photo-Fenton processes among other events, organic pollutants at natural pH conditions. [ABSTRACT FROM AUTHOR]

Four pineapple-growing soils (topsoil) were collected from Chonburi and Chachoengsao provinces in Thailand to analyze the physiochemical properties, chemical composition of organic carbon and diuron adsorption isotherm (batch experiment). Results revealed that diuron adsorption rate of soils was low (ranging between 1.81 and 27.63%) and adsorption data fit well with Freundlich equation (R² = 0.83-0.97), in which the adsorption coefficient (KF) is between 0.57 and 4.87 L kg-1. Soil organic matter and clay content were responsible for the adsorption of diuron in these soils (r = 0.95** and 0.78**, respectively). In addition, total nitrogen, silt content and cation exchange capacity also had a positive correlation with diuron adsorption in the soils. Organic carbon partitioning coefficient (KOC) of soils ranged from 125.84 to 480.36 L kg-1 and showed a positive correlation with the functional group of organic carbon, including aromatic carbon and carbonyl (r = 0.80** and 0.67*, respectively). This low rate of diuron adsorption in pineapple-growing soils posed a risk in diuron contamination in the environment. The increase of organic matter in these soils, particularly those coarse to medium-textured soils, through proper soil management would increase the herbicide adsorption ability of these soils and should subsequently reduce the contamination markedly. [ABSTRACT FROM AUTHOR]

Alamethicin (AMT) is a linear antimicrobial peptide isolated from fungi Trichoderma viride. To date, the mode of action of AMT in plant cells remains unknown. Our experimental results indicate that AMT causes leaf lesion attributed to its multiple effects on PSII. AMT decreases the O2 evolution rate of PSII. Based on chlorophyll fluorescence data, similar to the classical herbicide diuron, AMT interrupts PSII electron transfer beyond QA at the acceptor side, leading to the inactivation of the PSII reaction centers. Additionally, AMT decreases chlorophyll content and destroys the architecture of PSII pigment assemblies. However, AMT does not affect the oxygen-evolving complex at the donor side of PSII. Thus, it is concluded that AMT is a natural photosynthetic inhibitor with several action sites in PSII. [ABSTRACT FROM AUTHOR]

This work was focused in to develop an electroanalytical method based on a direct modification of a glassy carbon electrode (GCE) by the deposition of successive aliquots of diluted dispersions of functionalised carbon nanotubes (MWCNT-COOH) in ethanol (0.1 mg.mL−1) aiming the determination of Diuron into seawater samples, a common antifouling substance, using differential pulse voltammetry as electroanalytical technique. The GCE/MWCNT-COOH showed a sensitivity of 2.20 μA/μmol L−1 about 10 times higher than the unmodified counterpart (GCE) which showed a sensitivity of 0.192 μA/μmol L−1. The limits of detection and quantificationwere 6.88 × 10−8 and 2.29 × 10−7 mol L−1 for GCE/MWCNT-COOH while for GCE were 7.87 × 10−7 and 2.62 × 10−6 mol L−1, respectively. The applicability was evaluated with spiked detectable amounts of Diuron into seawater samples. The recovery results were between 76% and 119%. [ABSTRACT FROM AUTHOR]

The possibility to remove herbicide diuron from waste waters without using chemicals by applying a novel hydrodynamic cavitation technology was investigated. Hydrodynamic cavitation device with a cavitator of Venturi type for waste water purification was constructed. The hydraulic characteristics of the device were determined: the dependences of flow and cavitation number on inlet pressure. The effect of cavitation number, number of passes, pH and temperature on the reduction of concentration of diuron in aqueous solution was examined. The kinetics and the kinetic model have been established and the kinetic parameters of diuron removal were calculated. [ABSTRACT FROM AUTHOR]

Diuron is a herbicide that is considered potentially toxic. The conventional water treatments are not effective for its removal. Biosorption using Moringa oleifera emerges as an alternate process. Thus, this study evaluated Diuron's biosorption in biosorbents derivated from the fruits of Moringa oleifera. The biosorbents were characterised by scanning electron microscopy, Fourier transform infrared spectroscopy, textural characterisation and pH of zero load. The assays were performed in batch and evaluated the effects of parameters of contact time, pH, shaking speed, dose and granulometry of biosorbent at the biosorption process. The kinetic study was carried out, the models of pseudo-first and pseudo-second order were adjusted to the experimental data, being that the model that best fit was the pseudo-second order (qe and R2 in the range of 0.1339-0.1395 and 0.9849-0.9990, respectively). Adsorption isotherms were obtained at three temperatures (25°C, 35°C and 45°C) and analysed using the models Langmuir, Freundlich, Dubinin-Radushkevich and Temkin models. The model that best represented the experimental data was the Freundlich isotherm (n in the range 1.144-1.353, indicating that the biosorption is favourable). The thermodynamic properties showed that the biosorption of diuron was spontaneous and viable for the three biosorbents studied. Due to good capacity of removal of diuron (50%-74%), it can be said that the biosorbents studied are promising materials for the elimination of diuron from contaminated water. [ABSTRACT FROM AUTHOR]

Aromatic pesticides are toxic substances for the environment and humans. In this study, the photodegradation kinetics, the rate of leach ability in soils and the analytical determination of diuron and metalaxyl residues in well water by liquid-liquid extraction procedure have been determined by UV-visible absorption and photochemically-induced fluorescence (PIF). We studied the photodegradation kinetics by UV-visible absorption spectroscopy and a second-order kinetics with lifetime values of 6.0 and 0.5 hours was found in water for metalaxyl and diuron, respectively. Physicochemical parameters affecting the sensitivity of the PIF method, such as solvent, pH and UV irradiation time were investigated. PIF method was then performed in optimal analytical conditions. The limits of detection (LOD) ranging from 3.2 to 14 ng mL−1 were particularly low and the small relative standard deviation (RSD) (< 4 %), indicated a very good analytical sensitivity and a great repeatability of PIF method. Then, an investigation the pesticides leach ability was conducted in agricultural soil. We obtained rates of infiltration of 12.7 mm/min for diuron and 1.6 mm/min for metalaxyl. These results showed that both pesticides have high groundwater pollution potential. Finally, application to the analysis of these pesticides in spiked well water samples yielded satisfactory recovery values (87-108 %). [ABSTRACT FROM AUTHOR]

• Alexandrium pacificum efficiently eliminates diuron from seawater. • Diuron inhibits paralytic shellfish toxins (PSTs) synthesis and cell growth in A. pacificum. • A potential mechanism governing diuron absorption and subsequent reduction in PSTs biosynthesis. Diuron (N-(3,4-dichlorophenyl)-N,N‑dimethylurea, DCMU), a ureic herbicide, is extensively used in agriculture to boost crop productivity; however, its extensive application culminates in notable environmental pollution, especially in aquatic habitats. Therefore, the present study investigated the effect of diuron on the dinoflagellate Alexandrium pacificum , which is known to induce harmful algal blooms (HAB), and its potential to biodegrade DCMU. Following a four-day DCMU exposure, our results revealed that A. pacificum proficiently assimilated DCMU at concentrations of 0.05 mg/L and 0.1 mg/L in seawater, attaining a complete reduction (100 % efficiency) after 96 h for both concentrations. Moreover, evaluations of paralytic shellfish toxins content indicated that cells subjected to higher DCMU concentrations (0.1 mg/L) exhibited reductions of 73.4 %, 86.7 %, and 75 % in GTX1, GTX4, and NEO, respectively. Exposure to DCMU led to a notable decrease in A. pacificum 's photosynthetic efficacy, accompanied by increased levels of reactive oxygen species (ROS) and suppressed cell growth, with a growth inhibition rate of 41.1 % at 72 h. Proteomic investigations pinpointed the diminished expression levels of specific proteins like SxtV and SxtW, linked to paralytic shellfish toxins (PSTs) synthesis, as well as key proteins associated with Photosystem II, namely PsbA, PsbD, PsbO, and PsbU. Conversely, proteins central to the cysteine biosynthesis pathways exhibited enhanced expression. In summary, our results preliminarily resolved the molecular mechanisms underlying the response of A. pacificum to DCMU and revealed that DCMU affected the synthesis of PSTs. Meanwhile, our data suggested that A. pacificum has great potential in scavenging DCMU. [Display omitted] [ABSTRACT FROM AUTHOR]

Novelty Statement. The graphite powder was successfully doped in waste alum sludge by using sol-gel and embedding method, calcined at 700 ℃ to prepare a novel particle electrode (GP/AS), which could removal efficiency of diuron exceed 82% in wide pH ranges (3–11) superior to presented. It was attributed that the surface-bond free radicals and 1O 2 generated in GP/AS 3D system can resist the influence of pH on diuron degradation. The generated graphite structure and electron hole accumulation of GP/AS which greatly promoted active species, were systematically characterized using SEM, XRD, FT-IR and XPS. In addition, five proposed pathways of diuron degradation demonstrated that the main targets attacked by ROS contain aromatic ring, amide group, methyl group, and the diuron degradation was mainly achieved through hydroxylation. [Display omitted] • A novel supported AS particle electrode was firstly applied in EAOP system. • Removal efficiency can reach 82% in wide pH ranges (3–11). • GP/AS system can generate surface-bond free radicals and 1O 2. • The graphite structure and electron redistribution can promote ROS production. • Five diuron degradation pathways were inferred and the methyl group hydroxylation was dominant. The removal of diuron in electrochemical advanced oxidation process is typically limited by the solution pH. In this study, graphite powder (GP) was successfully doped in alum sludge (AS) by a sol–gel and embedding method and then calcined at 700 ℃ to prepare a novel particle electrode (GP/AS). The results showed that the GP/AS system can effectively degrade more than 82 % of diuron over a wide pH range (3–11) within 40 min. This was attributed to the surface-bonded free radicals and 1O 2 generated in the GP/AS system resisting the influence of pH on diuron degradation. The generated graphite structure and electron hole accumulation of GP/AS, which greatly promoted the formation of active species, were systematically characterized using scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. In addition, five pathways of diuron degradation were proposed, with similar steps being the main targets attacked by reactive oxygen species, including the aromatic ring, amide group, and methyl group. The dominant step was methyl group hydroxylation. The findings of this study provide an efficient and sustainable method for the application of reused waste mineral materials in water remediation. [ABSTRACT FROM AUTHOR]

Diuron is a globally used herbicide for weed control but has anti-androgenic effects on androgens (testosterone and androstenedione), antagonist effects on thyroid hormone signaling, and haematological effects due to their biotransformation in fish. Endocrine-disrupting biomarkers such as thyroid hormones, sex hormones, and haematological indices of Clarias gariepinus sub-adults exposed to sub-lethal diuron concentrations were studied over a 28-day period. C. gariepinus (n = 200) sub-adults were exposed to sub-lethal concentrations (0.00, 0.09, 0.18, 0.26, and 0.35 mg/L) of diuron. Changes in the hormonal and haematological profiles of the exposed fish were concentration and exposure duration-dependent. The thyroxine (T4), tri-iodothyronine (T3), and 17β-estradiol (E2) profiles decreased with an increase in concentration and exposure duration. The haemoglobin, pack cell volume, red blood cell, white blood cell, mean cell volume, and mean corpuscular haemoglobin cell decreased, while the mean corpuscular haemoglobin increased with an increase in concentration and exposure duration. Diuron induced stress and altered the physiological mechanisms of fish, and its application in farmlands should be regulated so as to enable a sustainable aquatic eco-system and fishery resources. [Display omitted] • Diuron was toxic even at very low concentration. • Diuron showed endocrine disrupting potential. • The toxicant altered the hormonal and haemoglobin profile of the exposed fish. • The alterations were concentration and exposure duration dependent. • Results showed the need to regulate the application of pesticides on farmlands. [ABSTRACT FROM AUTHOR]

The selectivity of diuron for most crops, is due to the positioning of its molecule in the soil profile. Therefore, it is necessary to know the interactions of diuron's molecule with soil matrix to define recommended doses from an agronomic and environmental standpoint. This research aimed to estimate the influence of soil attributes and sorption coefficient (K f) on the definition of diuron doses. Experiments were conducted to quantify the K f of diuron in different soils and determine the doses in each soil that caused 80% intoxication (C 80 intoxication) and 80% decreased accumulation of aerial parts plants (C 80 DMAP) of Eleusine indica. After that, a correlation analysis was performed between the soil physical-chemical attributes, diuron K f , and C 80 of E. indica intoxication. Diuron K f ranged from 1.8, in the ultisol with 0% of manure content, to 8.8, in the oxisol with 40% of manure content. Eleusine indica C 80 ranged from 66.3, in the oxisol with 0% of manure content, to 568.3 g a.i. ha−1, in the ultisol with 40% of manure content, while C 80 of aerial part dry matter reduction ranged from 57.5 to 521.6 g a.i. ha−1 in the same soils. C 80 intoxication positively correlated with organic matter content and K f. It was concluded that organic matter content was determinant in diuron sorption and intoxication for E. indica. Changes are necessary in the dosing recommendation criteria in the label of diuron, with its recommendation being primarily based on the organic matter content. • To recommend herbicides based on soil texture is an outdated practice given the high heterogeneity of Brazilian soils. • The sorption of diuron is dependent on the soil's organic matter content and influences weed control. • The dosage recommendation for diuron should be based on the soil organic matter content. [ABSTRACT FROM AUTHOR]