Although recent work has shown natural lignin products are promising to fabricate various polymer based functional composites, high-value applications were challenged by their structural complexity and inhomogeneity. This work specially assessed the potential of four technical lignins for cellulose based functional films production. These four technical lignins were obtained by emerging pretreatment systems, i.e., lactic acid-betaine deep eutectic solvent (DES), ethanol organosolv, soda/anthraquinone (Soda/AQ) and the sodium salicylate hydrotrope, and their phenolic substructures were comparatively identified by prevalent ³¹P NMR technique. The influence of lignin chemical structure on the antioxidant potential and UV-shielding performance of the prepared cellulose/technical lignin composite films were assessed. Results showed severe organosolv and soda/AQ pretreatment produced technical lignins with higher total phenolic hydroxyl groups (3.37 and 3.23 mmol g-1 respectively), which also exhibited higher antioxidant activities. The composite films could effectively block the ultraviolet lights especially for UVB region (ultraviolet B, 280–315 nm) at only 5 wt.% lignin content. The contribution of lignin phenolic substructures to both antioxidant activity and UV-shielding property from high to low was syringyl > guaiacyl > p-hydroxyphenyl phenolic hydroxyl groups. This work provided some useful information that could facilitate upstream lignin extraction or downstream value-added applications.

Agricultural activities and agro-inputs, particularly chemical fertilizers, farmyard manure, pesticide, sewage sludge, plastic mulch, irrigation, etc., are the primary source of pollutants in farmlands. Agricultural land degradation has become a major concern as it poses a threat to crop productivity. In recent years, microbial-assisted phytoremediation has gained much attention as a promising in situ remediation technology for cleaning polluted soils. Several beneficial rhizobacteria and endophytes facilitate phytoremediation by stimulating innate plant growth-promoting traits such as the production of siderophores, phytohormones, and chelators in addition to their ability to biodegrade contaminants and enhance their removal. Current studies on microbial mediated phytoremediation are demonstrating significant remediation potential. However, there are several challenges in the field that restrict the remediation process. Here we highlight the specific traits, mechanisms, roles, advantages, and problems associated with microbial-assisted phytoremediation.