Hot foam for weed control-Do alkyl polyglucoside surfactants used as foaming agents affect the mobility of organic contaminants in soil?

Classification of surfactants and admixtures for producing stable aqueous foam

Surfactants and foam have captured the interest of researchers worldwide due to their unique behavior of surface activity, the dynamic nature of foam formation, and simultaneous destruction. The present review focuses on the surfactants' classification, surfactant-solvent interaction, foam formation, characteristics, and a range of admixtures to enhance the foam performance. Although surfactants have been researched and developed for decades, recently, their sustainability has been given special attention. One such aspect is the development of green foaming agents from natural and renewable sources and assessing their suitability for different applications. Further, widely researched parameters are the type of surfactant, surfactant concentration, surfactant-solvent interaction, and foam production method on the foamability of a surfactant solution and related foam characteristics, including stability and texture. However, still, there is no rule to predict the best foam. Another vital concern is the non-standardization of foam assessment methods across industries and regions. Recently, research has progressed in identifying suitable admixtures for foam performance enhancement and utilizing them to produce stable foams for application in enhanced oil recovery, drug delivery, and manufacturing of aerated food products and foamed concrete. Although foam stabilization using various admixtures has been recognized well in the literature, the underlying mechanism requires further research. The interaction of surfactant and admixtures in solution is complicated and requires more research.

Glyphosate uses, adverse effects and alternatives: focus on the current scenario in Brazil

Brazil, a global frontrunner in pesticide consumption and sales, particularly glyphosate, appears to be at odds with other countries that increasingly ban these products in their territories. This study gathers the values of Acceptable Daily Intake and Maximum Residue Limits (MRL) in the European Union for dozens of substances and subsequently contrasts them with the corresponding benchmarks upheld in Brazil concerning its predominant crops. Furthermore, this study delves into the toxicity levels and the potential health ramifications of glyphosate on humans through the ingestion of food containing its residues. The findings from this research underscore a notable surge in glyphosate and pesticide sales and usage within Brazil over the past decade. In stark contrast to its European counterparts, Brazil not only sanctioned the sale and application of 474 new pesticides in 2019, but extended the authorization for glyphosate sales while downgrading its toxicity classification. Finally, this review not only uncovers disparities among research outcomes but also addresses the complexities of replacing glyphosate and introduces environmentally friendlier alternatives that have been subject to evaluation in the existing literature.

Comparison between flaming, mowing and tillage weed control in the vineyard: Effects on plant community, diversity and abundance

The effect of different management techniques for plant control in the vineyard were compared in the present work, focusing on plant diversity preservation and management efficacy in a two-year experiment on vineyard row weed community. Biomass-fueled flame weeding (with two intensities) was applied as an innovative plant control technique in contrast to tillage and mowing practices. The results showed that flaming was comparable to tillage regarding weed control effectiveness, and was more efficient than mowing. However, species number and functional evenness were not substantially modified by changing the applied management technique. Functional trait analysis demonstrated that row management significantly affected the frequency of annual plants, plant height, root depth index, and the occurrence of plants with storage organs. As for species composition, meaningful differences were found: only the two flaming treatments (i.e. gentle vs intense) and the gentle flaming vs mowing had consistent species composition. Flame wedding showed some potential benefits in plant control in the vineyard by favouring small plant and controlling overall weed abundance. On the other hand, flaming favoured plant species with asexual reproduction, with a potential negative impact on weed-vine competition and species persistence in the vineyard. Further studies are required to investigate such contrasting aspects, also considering other weed control techniques (e.g. cover-crops), considering a sustainable perspective of an herbicide-free environment.

Decyl glucoside surfactant Triton CG-110 does not significantly affect the environmental fate of glyphosate in the soil at environmentally relevant concentrations

Glyphosate is the most common herbicide worldwide, and its impact on the environment has increasingly been scrutinized. Glyphosate-based formulations can contain co-formulants, among which are surfactants. This study aimed to investigate whether the presence of an alkyl polyglucoside-based surfactant, Triton CG-110, affects the adsorption, leaching, and mineralisation of glyphosate in the soil. The experiments were conducted in two soils with different textures (sandy and clay) and in washed sand. Glyphosate and surfactant mixtures were applied at realistic field rates. Because of ponding and scarce leaching from the field soil, the leaching experiments were conducted only with washed sand. The results indicate a reduction of glyphosate adsorption in washed sand (from K_f = 13.5 to 3.99 μg^1-1/n (ml)^1/n g^-1) and in sandy soil (from K_f = 165 to 90.8 μg^{1-1/ n} (ml)^1/n g^-1) when using a Triton CG-110 concentration of 0.5 %, which corresponds to that of a spraying solution applied in the field, whereas adsorption in clay soil was unaffected. Triton CG-110 did not significantly affect glyphosate leaching in washed sand or mineralisation in any of the tested soils. The results indicate that Triton CG-110 is unlikely to significantly affect the environmental fate of glyphosate in the soil at environmentally relevant concentrations.

Influence of alkyl polyglucoside, citric acid, and nitrilotriacetic acid on phytoremediation in pyrene-Pb co-contaminated soils

At present, the remediation for organic pollutants and heavy metals co-contaminated soils is a challenge which needs to be broken through. In this study, alkyl polyglucoside (APG), citric acid (CA), and nitrilotriacetic acid (NTA) were chosen to enhance the phytoremediation of pyrene and Pb co-contaminated soils by perennial ryegrass. Through the comparison of the results with different applications, it could be found that the application of NTA was beneficial to the growth of perennial ryegrass, the underground and aboveground biomass were increased by 172.9-236.1% and 61.9-142.8%, respectively, meanwhile, photosynthetic activity of perennial ryegrass was affected positively. More importantly, the combined application of APG and NTA maximally promoted the accumulation and translocation of Pb (BF/TF, 0.44/0.61) and dissipation of pyrene (71.6%). These results indicated that the combined application of APG and NTA could be promising for future practical application of phytoremediation. However, the optimal dosage ratio of APG and NTA for phytoremediation needs to be further researched.