Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes最新文献

Water pollution associated with antibiotic residues and colored organic pollutants leads to various potential risks to human health and the environment. This work develops an economical method that is suitable for removing both antibiotic residues and colored organic pollutants from water. The oxidation process based on a noble metal (Ag)-doped zinc oxide photocatalyst (Ag-ZnO) was selected as a potential strategy for investigation. Besides, tetracycline antibiotic residues (A-Tc) and methylene blue-colored organic pollutants (D-Mb) were selected as target contaminants. With light assistance, Ag-ZnO showed significantly improved degradation efficiency for A-Tc and D-Mb at 90.6 and 97.3%, respectively. The advantages of Ag-ZnO are also confirmed by the faster degradation rate constants, which are more than twice as fast as those of the undoped sample. The mineralization process shows that 93.5% and 98.7% of organic carbon were removed from the A-Tc and D-Mb solutions, respectively. The result suggests that antibiotic residues and colored organic pollutants are being converted into inorganic substances. In addition, the benefits of using Ag-ZnO to enhance human health safety, reduce the negative effects on the environment, and decrease treatment costs are discussed.

The combination of auxin-mimicking herbicides from different chemical groups offers an alternative for controlling fleabane (Conyza spp.) in soybean pre-sowing, but care is needed to avoid phytotoxicity. This study evaluated the effectiveness of auxinic herbicide mixtures in controlling Conyza spp. and their residual effects on soybean plants. A randomized block field experiment tested 13 combinations of auxinic herbicides with glyphosate, followed by glufosinate 14 days after application (DAA). At 42 DAA, all the treatments provided satisfactory control, with triclopyr + halauxifen + diclosulan achieving 100% effectiveness, while the 2,4-D combinations were controlled at 80-90%. Aminopyralid caused the highest phytotoxicity (50-75%), while dicamba caused less than 25% phytotoxicity. Aminopyralid also significantly reduced yield and thousand-grain weight to nearly zero, whereas the other treatments maintained yields of approximately 2,500 kg ha^-1. These results demonstrate the efficacy of auxinic herbicide combinations for managing Conyza spp., provided that the phytotoxic risks to soybean are carefully managed.

This study explores the photocatalytic decomposition of antibiotic residues, including tetracycline (TCR) and amoxicillin (AMR), from wastewater using Bi₂O₃@C₃N₄ photocatalyst. The characterization findings revealed that Bi₂O₃@C₃N₄ exhibited significantly improved light absorption properties and enhanced charge separation efficiency. According to the experimental results, Bi₂O₃@C₃N₄ exhibited high degradation efficiencies of 77.6% for TCR and 83.2% for AMR in wastewater samples. It also displayed excellent reusability, with the removal efficiencies of TCR and AMR remaining at 71.3 and 78.8%, respectively, after five cycles. Additionally, the photodegradation of TCR and AMR using Bi₂O₃@C₃N₄ is suggested to follow the Z-scheme pathway. The results of this study could be utilized for removing antibiotic pollutants from wastewater, thereby reducing their impact on human health and the environment.

The widespread use of antibiotics has led to significant water pollution. Photocatalysis can effectively degrade antibiotics, but the performance is greatly limited by the photogenerated carrier recombination in the photocatalytic material g-C₃N₅. Constructing heterojunctions can enhance interfacial charge transfer, leading to more stable and efficient photocatalysis. This study synthesized a Fe₂O₃/g-C₃N₅ heterojunction using the solvothermal method. The Z-scheme charge transfer mechanism facilitated efficient separation of photogenerated carriers, preserving photoelectrons and holes with high redox activity. This process generated a substantial amount of highly reactive free radicals such as ·O₂^- and ·OH, enabling the efficient degradation of tetracycline (TC). Under the optimal conditions of initial concentration of TC was 200 mg/L, the quality ratio of Fe₂O₃ and g-C₃N₅ was 1:2, the catalyst dosage was 50 mg and pH = 7.0, the TC degradation rate reached 92.46% within 60 min of visible light irradiation. The photocatalytic activity's enhancement was attributed to broad spectral absorption and effective photogenerated carrier separation. Furthermore, the photocatalytic performance can be affected by the presence of inorganic salt ions such as HCO₃^- and CO₃^2-.

The objective of this study was to evaluate the selectivity of four post-emergence herbicides in the cultivation of industrial hemp. Hemp was grown in 3.5 L pots with inert substrate in the absence of weeds throughout the crop cycle. The experimental design adopted was a randomized, complete block design with five treatments and four replications. The herbicides atrazine (2.500 g a.i./ha), clethodim (96 g a.i./ha), fomesafen (250 g a.i./ha), and nicosulfuron (54 g a.i./ha) were applied when the plants were approximately 35 days after cutting. Visual assessments of herbicide-induced injury symptoms were conducted, along with measurements of the number of leaves, plant height, stem diameter, and total aerial part dry mass. When nicosulfuron was applied after emergence, it caused 60.0% damage 21 days after application (DAA), which changed the number of leaves, height, stem diameter, and total aerial part dry mass of hemp plants in a big way. Fomesafen caused 42.5% injury at 5 DAA, and atrazine caused 42.5% injury at 21 DAA, which may compromise the final yield. Therefore, it is recommended to use only clethodim, a selective herbicide for broadleaf plants such as hemp, as it did not cause significant injuries during the evaluation period.

Bioherbicides, including plant extracts, allelochemicals, and microbial agents, offer sustainable alternatives for weed control in agriculture. In Brazil, the native tree Esenbeckia leiocarpa (guarantã) shows potential phytotoxic effects in weeds species. This study evaluates aqueous extracts from its aerial parts as a substitute for herbicides, focusing on their impact on weed germination and initial growth. The experiment used a completely randomized 7 × 4 factorial design with seven extract concentrations (0, 5, 10, 20, 40, 80, and 100%) and four weed species (Amaranthus hybridus, Bidens pilosa, Euphorbia heterophylla, and Digitaria insularis), with four replicates per treatment. Germination and germination speed index dropped significantly even at 5%, nearly ceasing at 20% or higher. The results indicate a non-linear dose-response relationship, suggesting that increasing the extract concentration beyond 20% does not result in a proportional reduction in germination. Pre-germinated seeds showed reduced radicle length and fresh mass from 5%, with E. heterophylla least affected and D. insularis most sensitive. Phytotoxic effects increased with concentration, except for D. insularis, where phytotoxicity stabilized (90% phytotoxicity) at concentrations above 20%. When applied to leaves, phytotoxicity was minimal, ranging from 5 to 10%, and had negligible effect on reducing fresh mass. The findings indicate that the response to E. leiocarpa leaf extract varies among the weed species evaluated, primarily affecting germination with minimal impact when applied to leaves. Thus, E. leiocarpa demonstrates potential as a bioherbicide for pre-emergent applications against the species studied.

In this work, we fabricated the Fmoc-Pro-Phe-OMe modified carbon paste electrode (FPPO/MCPE) and used it for electrochemical detection of CP and FZ in a 0.1 M phosphate buffer solution (pH = 7). We characterized the Fmoc-Pro-Phe-OMe and applied it for the electrochemical detection of CP and FZ. The Mass spectroscopy, ¹HNMR, and FTIR measurements confirm the Fmoc-Pro-Phe-OMe chemical structure. Studying electrochemical sensor characteristics, variation of scan rate parameters, and electrode surface area is crucial for understanding and optimizing the performance of modified and unmodified carbon paste electrodes. The FPPO/MCPE-modified carbon paste electrode has better sensing capabilities than the unmodified bare carbon paste electrode (BCPE). The FPPO/MCPE sensor has two linear ranges: 50-450 μM (CP) with a detection limit of 0.014 μM and 50-450 μM (FZ) with a detection limit of 0.015 μM. The FPPO/MCPE sensor is highly sensitive, measuring 4.25 µA/µM/cm² for CP and 4.1 µA/µM/cm² for FZ. Scan rate and concentration tests demonstrate that the oxidation of CP and FZ is a diffusion-controlled electrode process. The FPPO/MCPE sensor also demonstrates excellent repeatability, reproducibility, stability, and selectivity for detection of CP and FZ. The use of FPPO/MCPE-sensor is demonstrated for the detection of FZ and CP in milk and honey samples.

The objective of this study was to assess the performance of indaziflam under different soil cover materials in coffee cultivation, focusing on its agronomic efficacy, residual effects, and influence on the weed community. The studies were carried out at two farms: IPACER (sandy clay Oxisol - OXI_sc) and Glória (clay Oxisol - OXI_cl). Evaluation factors included the application of indaziflam (75 g a.i. ha^-1), different soil cover materials (crop debris, organic compost, and bare soil), and the evaluation period was from 30 to 180 d after application (DAA). The agronomic efficacy and residual effect were assessed by injury level, and the indaziflam's residual lifetime (RL₅₀) was estimated using a first-order model. Phytosociological parameters, including absolute and relative frequency, density, abundance, and the importance value index, were evaluated. The results indicated that agronomic efficacy remained above 90% until 120 DAA in all treatments with indaziflam application, with RL₅₀ exceeding 180 days. Weed indices were higher in areas without indaziflam, but treatment similarity analysis revealed that the weed community was primarily influenced by soil type, with a lesser impact from soil cover. Neither crop residues nor organic compost compromised indaziflam efficacy, indicating their suitability for coffee cultivation without the need to increase herbicide doses.

Pesticide dislodgeable foliar residues (DFR) and their dissipation half-time (DT₅₀) after application are important parameters for exposure and risk assessment from intended reentry activities or unintended dermal contact with treated crops. To understand the impact of agronomic factors on residue level a statistical based evaluation was conducted using ten DFR studies, with pyrimethanil applied in Scala^® to strawberries, raspberries, peppers, apples, and grapes, 30 trials in total. Influences on initial DFR (DFR0) and DT₅₀ were investigated by multivariate linear regression analysis. The application rate and the crop itself indicate a potential influence on DFR0 when related to ground area applied which is not notable for three dimensional crops regardless of indoor/outdoor cultivation, when related to leaf wall area (LWA). DFR0 values for pyrimethanil do not depend on the number of applications as the range of DT₅₀ values determined for pyrimethanil is consistently small (0.3-2.3 days). All DT₅₀ are significantly lower than the European default (30 days). The noted difference in DT50 of peppers to strawberries is likely attributable to indoor cultivation. A proposal is made how to refine the exposure assessment of pyrimethanil making use of the available DFR0 and DT₅₀ data for other crop types.