Due to the widespread use of engineered nanomaterials (ENMs) for soil remediation and nano-enabled sustainable agriculture, there is a growing concern regarding the behavior and fate of ENMs released into soil systems in the presence of natural root exudates (REs). Herein, we investigate the influence of REs on the fate and ecological effect of ENMs from a comprehensive perspective. We summarize the key roles reported in the literature for REs in physical changes (e.g., adsorption, dispersion/aggregation), chemical changes (e.g., oxidation/redox reactions, and dissolution), and biotransformation of ENMs, which will further determine the ecological risk of ENMs in natural soil systems. Moreover, this review highlights the potential adverse effects of ENMs on different soil organisms (e.g., bacteria, plants, and eisenia foetida) in the presence of REs. The remaining unclear mechanisms (e.g., oxidative stress and DNA damage) of ENMs toxicity at the cellular level influenced by REs are reviewed and presented. Finally, the review concludes by addressing the current knowledge gaps and challenges in this field.

Benzo[a]pyrene (B[a]P) as a representative polycyclic aromatic hydrocarbons is concerned by global scientists in various fields, but its biological and biochemical actions in soil-wheat systems are still rarely reported. The B[a]P as a ubiquitous soil pollutant possesses varied contents in real environment, and herein was studied in systems of soil and wheat to obtain relative results to reveal their variations in different systems. Its bioavailability (extractability and bioaccumulation) and basic biological toxicity were tested based on three typical soil types (red, black, and brown) in China and spiked amounts (0.1, 1, and 10 mg/kg) with several orders of magnitude. Results showed that B[a]P concentrations in soil-wheat systems extracted by HPCD were insignificantly (p > 0.05) higher than Tenax-TA, and varied with soil types and spiked concentrations. Besides, the root and shoot length were mostly inhibited, in a range of -21.85%-26.35% and -0.48%-54.85%, respectively, by B[a]P in different soil types and increased with its increasing concentration. Comparatively, higher bioconcentration factor and translocation factor values were observed under lower group in red soil-wheat systems, and higher spiked groups in black and brown soil-wheat systems. Moreover, inhibitive effects posed by B[a]P were mainly targeted at wheat shoots in these soils. The simultaneous studies provided a comparable knowledge of B[a]P in ecosystems of different soil types combined with different plant species due to lots of variations, further to serve for contaminated soil remediation and sustainable agricultural management.

A document by kumanan Bharathi yazhini. Click on the document to view its contents.

Cotton is one of the most important raw materials for textile and clothing production. Compared with some synthetic polymer fibers, the main drawback of cotton fibers is its poor mechanical properties and its high flammability, and therefore it cannot be used for special textiles. Cotton fabrics treated with modern flame-retardant and reinforcement finishes often cannot meet rigid military specifications. polypyrrole-Magnesium oxide (ppy-MgO) and polypyrrole-Magnesium oxide-Carbon nanotube (ppy-MgO-CNT) composites were prepared with various weight ratios by in-situ chemical polymerization method. 1, 2, 3, 4-butane tetracarboxylic acid (BTCA) was used as cross-linking agent in presence of sodium hypophosphite (SHP). The composite sol was coated on cotton fabric using pad-dry-cure technique. The coated cotton fabrics were characterized by SEM, EDAX, XRD, UV-DRS and FT-IR analysis and tested for flame retardant and UPF application. It was found that ppy-MgO-CNT composite was found to be efficient.