npj Clean Water最新文献

Photocatalytic water purification is an environmentally sustainable approach, but limited by low efficiency due to challenges with photocatalysts and mass transfer. Optofluidic microreactors can address these constraints, yet optimizing reactor configurations and photocatalyst designs remains challenging. Here, we present a novel planar packed-bed optofluidic microreactor (PPOM) using titanium dioxide nanoflowers (TNFs) decorated with gold nanoparticles (Au/TNFs) and conduct a pilot study on efficient visible light-driven water purification. Compared to TNFs in slurry-mode, the Au/TNFs achieve 46-fold enhancement in photodegradation efficiency due to the plasmonic effect, further boosted to 2,700-fold enhancement in the PPOM configuration by improving surface area, light harvesting, and mass transfer. The PPOM also shows a 7-fold efficiency increase compared to planar film-mode microreactors. Theoretical analysis elucidates the influences of plasmonic effect and reactor configuration on the enhanced photocatalytic activity, emphasizing the potential of integrated optofluidic systems and plasmonic-semiconductor heterostructures for sustainable water treatment and energy applications.

Investments in “Clean water and sanitation” drive a transition from irrigation with untreated to irrigation with treated wastewater. While this transition reduces many health risks, it may decrease crop yields, and soil carbon storage, cause a release of accumulated pollutants from soils, and increase the spread of antibiotic resistance in the environment. A holistic view on multiple SDGs is necessary to maximize benefits and minimize risks of wastewater treatment for irrigation.

Traditional biological wastewater treatment struggles to efficiently remove refractory organic nitrogen compounds (RONCs). This study demonstrates the potential of alternating current (AC)-driven bioelectrodes for deep mineralization of nitrobenzene (NB) by coupling in situ reduction and oxidation reactions. Sine-wave AC bioelectrodes overcome the limitations of direct current (DC) systems, achieving 97.6% NB reduction, 90.9% intermediate mineralization, and 80.8% total nitrogen removal while reducing energy consumption by 22.3%. AC stimulation enhances biofilm formation and bidirectional electrocatalytic activity, leading to higher biomass and electron utilization efficiency. Multi-omics analysis shows enrichment of functional microbial consortia involved in NB reduction, aromatic compound oxidation, ammonia oxidation, nitrate/nitrite reduction, and electron transfer, with upregulated enzyme gene expression. Carbon metabolites from catechol meta-cleavage support nitro-reduction, denitrification, and cell viability without external carbon sources. Nitrification-denitrification is the primary pathway for inorganic nitrogen removal. This AC bioelectrode offers an efficient, low-carbon solution for RONC mineralization in wastewater.

The global need for clean water and sanitation drives the development of eco-friendly and efficient water treatment technologies to combat biological pollution from pathogens. In this study, a novel heterojunction photocatalyst was synthesized by incorporating ZnIn₂S₄ into covalent organic frameworks (COFs) to enable environmentally friendly hydrogen peroxide (H₂O₂) photosynthesis and explore its potential for in situ disinfection. The ZnIn₂S₄/COF photocatalyst achieved remarkable H₂O₂ yields of 1325 µmol∙g⁻¹∙h⁻¹, surpassing pristine COF and ZnIn₂S₄ by factors of 3.12 and 16.2, respectively. The produced H₂O₂ was efficiently activated into hydroxyl radicals (·OH) through reaction with Fe(II), enabling rapid sterilization via a photocatalysis-self-Fenton system. Mechanistic insights, supported by physicochemical characterizations and theoretical calculations, highlighted the role of the internal electric field (IEF) in enhancing carrier separation and transfer, thereby boosting photosynthesis efficiency. This work presents a sustainable approach to H₂O₂ photosynthesis and activation for disinfection, offering a promising solution to global water treatment challenges.

The growing global demand for freshwater necessitates advanced water treatment technologies. This review highlights the application of fibrous silica spheres, KCC-1, in water remediation, focusing on the removal of heavy metals and organic dyes. KCC-1’s unique fibrous morphology, high surface area, and physicochemical properties make it a promising adsorbent. This work examines its synthesis, modifications, and advantages, providing insights into optimizing KCC-1-based adsorbents for sustainable water treatment.

Current electrochemical membrane reactors (EMRs) focus on half-cell reactions, which limits their efficiency. Herein, an EMR-P with full-cell reactions was constructed using a carbon membrane (CM) as the cathode and a TiO₂-loaded CM as the anode. Noteworthy, this proposed innovative design has no ion-exchange membrane and consists of two permeates for anodic electrocatalytic and cathodic electro-Fenton processes. Results showed that the removal rates of phenol and COD by EMR-P were 99.2% and 93.9%, respectively, with energy consumption of 0.43 kWh kg COD^–1, which were superior to those of other EMRs. Such superior performance of EMR-P was attributed to the synergism of electro-Fenton and electrocatalytic oxidation, as well as the high adsorption property of CM, which promoted ({1atop}{rm{O}}_{2}) generation and COD removal. Additionally, the cathode made more contribution to the COD removal (59.0%) than the anode (41.0%). Overall, this work provides several insights into the design of EMRs for cleaning industrial wastewater.

This study is the first to quantify the migration processes of riverine microplastics under different connectivity contexts based on the spatial variation characteristics of microplastic loads. Microplastics in multidammed, single-dammed, and nondammed rivers are significantly different in three categories: abundance, flux, and inventory. Artificial damming can lead to multicategory reorganization of riverine microplastics, including size, polymer type, shape, and color. Artificial damming has led to the formation of microplastic hotspots in river waters and sediments due to reduced river mobility. Notably, low-velocity regions in non-dammed rivers are high hotspot for microplastic deposition, and their inventories may even be 10.63–12.71 times higher than those of other riverbeds. Additionally, results based on microplastic abundance differ significantly from those based on microplastic loads, which in some cases even showed contradictory results. Therefore, future studies must incorporate microplastic loads into the assessment to enhance our understanding of the fate of microplastics in river systems.