Microbial-driven ectopic uranium extraction with net electrical energy production

The extraction of uranium (U) from U-bearing wastewater is of paramount importance for mitigating negative environmental impacts and recovering U resources. Microbial reduction of soluble hexavalent uranium (U(VI)) to insoluble tetravalent uranium (U(IV)) holds immense potential for this purpose, but its practical application has been impeded by the challenges associated with managing U-bacterial mixtures and the biotoxicity of U. To address these challenges, we present a novel spontaneous microbial electrochemical (SMEC) method that spatially decoupled the microbial oxidation reaction and the U(VI) reduction reaction. Our results demonstrated stable and efficient U extraction with net electrical energy production, which was achieved with both synthetic and real wastewater. U(VI) removal occurred via diffusion-controlled U(VI)-to-U(IV) reduction-precipitation at the cathode, and the UIVO_(2) deposited on the surface of the cathode contributed to the stability and durability of the abiotic U(VI) reduction. Metagenomic sequencing revealed the formation of efficient electroactive communities on the anodic biofilm and enrichment of the key functional genes and metabolic pathways involved in electron transfer, energy metabolism, the TCA cycle, and acetate metabolism, which indicated the ectopic reduction of U(VI) at the cathode. Our study represents a significant advancement in the cost-effective recovery of U from U(VI)-bearing wastewater and may open a new avenue for sustainable uranium extraction.

Geometric nonlinear analysis of large rotation behavior of a curved SWCNT

Nanotubes form clusters and are found in curved bundles in nano-tube films and nanocomposites.Separation phenomenon is sus-pected to occur in these curved bundles.In this study,the deformation of a single-wall carbon nanotube(SWCNT)interacting with curved bundle nanotubes is analyzed.It is assumed that the bundle is rigid and only van der Waals force acts between the nanotube and the bundle of nanotubes.A new method of model-ing geometric nonlinear behavior of the nanotube due to finite rotation and the corresponding van der Waals force is developed using co-rotational finite element method(CFEM)formulation,combined with small deformation beam theory,with the inclusion of axial force.Current developed CFEM method overcomes the limitation of linear Finite Element Method(FEM)formulation regarding large rotations and deformations of carbon nanotubes.This study provides a numerical tool to identify the critical curvature influence on the interaction of carbon nanotubes due to van der Waals forces and can provide more insight into studying irregula-rities in the electronic transport properties of adsorbed nanotubes in nanocomposites.

Anaerobic biodegradation of trimethoprim with sulfate as an electron acceptor

Trimethoprim(TMP)is an antibiotic frequently detected in various environments.Microorganisms are the main drivers of emerging antibiotic contaminant degradation in the environment.However,the feasibility and stability of the anaerobic biodegradation of TMP with sulfate as an electron acceptor remain poorly understood.Here,TMP-degrading microbial consortia were successfully enriched from municipal activated sludge(AS)and river sediment(RS)as the initial inoculums.The acclimated consortia were capable of transforming TMP through demethylation,and the hydroxyl-substituted demethylated product(4-desmethyl-TMP)was further degraded.The biodegradation ofTMP followed a 3-parameter sigmoid kinetic model.The potential degraders(Acetobacterium,Desulfovibrio,Desulfbbulbus,and unidentified Peptococcaceae)and fermenters(Lentimicrobium and Petrimonas)were significantly enriched in the acclimated consortia.The AS-and RS-acclimated TMP-degrading consortia had similar core microbiomes.The anaerobic biodegradation ofTMP could be coupled with sulfate respiration,which gives new insights into the antibiotic fate in real environments and provides a new route for the bioremediation of antibiotic-contaminated environments.