Effect of the Mineral-Microbial Complexes on the Quality, Soil Nutrients, and Microbial Community of Tailing Substrates for Growing Potted Rorippa

Effects of Graphene Oxide on Endophytic Bacteria Population Characteristics in Plants from Soils Contaminated by Polycyclic Aromatic Hydrocarbons

Environmental pollution stands as one of the significant global challenges we face today. Polycyclic aromatic hydrocarbons (PAHs), a class of stubborn organic pollutants, have long been a focal point of bioremediation research. This study aims to explore the impact and mechanisms of graphene oxide (GO) on the phytoremediation effectiveness of PAHs. The results underscore the significant efficacy of GO in accelerating the degradation of PAHs. Additionally, the introduction of GO altered the diversity and community structure of endophytic bacteria within the roots, particularly those genera with potential for PAH degradation. Through LEfSe analysis and correlation studies, we identified specific symbiotic bacteria, such as Mycobacterium, Microbacterium, Flavobacterium, Sphingomonas, Devosia, Bacillus, and Streptomyces, which coexist and interact under the influence of GO, synergistically degrading PAHs. These bacteria may serve as key biological markers in the PAH degradation process. These findings provide new theoretical and practical foundations for the application of nanomaterials in plant-based remediation of polluted soils and showcase the immense potential of plant-microbe interactions in environmental restoration.

Recyclable water-modified deep eutectic solvents for removal of multiple heavy metals from soil

Removing heavy metals from soil has always been a challenge in terms of safety and effectiveness. Deep eutectic solvents (DESs) are recognized as environmentally friendly reagents with great potential in the removal of heavy metals from soil. In this study, water was introduced as a third component to form new ternary deep eutectic water solvents (DEWSs) to improve their performance. The removal capacity, applicable conditions and mechanisms of sixteen DEWSs for heavy metals were systematically investigated. Experimental results showed that the presence of water significantly enhanced the removal efficiency of three DESs (Choline chloride plus Urea, DEU; Choline chloride plus l-lactic acid, DELA; and Choline chloride plus Ethylene glycol, DEEG) for heavy metals. However, as the molar ratio of water increased, the eutectic systems in the DEWSs weakened and eventually disappeared. Under optimum conditions, DEWLA7 (DELA : H2O = 2 : 8) showed the highest removal rate for cadmium, lead, copper and zinc, which were 43.42%, 94.73%, 90.72% and 96.44%, respectively. Hydrogen bonding, adsorption of oxygen functional groups, exchangeable hydrogen substitution, changes in viscosity properties and co-precipitation all contributed to the removal of heavy metals by DEWLA7. Notably, DEWLA7 had no significant effect on the content of major minerals and nutrients in the soil. Furthermore, DEWLA7 proved to be reusable for soil washing, and still retains a high removal rate of 37.32%-83.66% after multi-stage filtration treatment. Therefore, DEWLA7 was an unexplored and excellent soil washing agent with great potential in economic and social benefits.