The use of titanium oxide (TiO₂) in electrochemical systems has been intensively investigated for developing conductive and active electrodes. However, achieving an effective reaction using geometric and electronic structures remains a challenge. Herein, we report the in situ synthesis of TiO₂ mesocrystals within a flow-through titanium (Ti) plate using an electrochemical method. We developed an electrochemical reactive membrane (REM) for the rapid removal of organic pollutants from water. At a low current density (3 mA/cm²), the removal rate of p-nitrophenol through the TiO₂ mesocrystal–based REM was 95% within 20 min. The REM demonstrated a service lifetime of > 1900 h and an energy consumption of 30 kWh (kg⁻¹ chemical oxygen demand) for treating organic pollutants in water. The abundant nanochannels of TiO₂ mesocrystals can effectively regulate the hydroxy radical reaction pathway, promoting its interaction with organic compounds more compared with the anode. This greatly enhances the electrochemical oxidation of organic pollutants in aqueous solution.

Contact-electro-catalysis (CEC) is an emerging catalytic approach that converts mechanical energy into chemical redox activity through contact-electrification-induced interfacial electron transfer. By enabling redox reactions at dynamically contacting interfaces without continuous electrical bias or light irradiation, CEC expands the catalyst landscape beyond conventional semiconductors and metals to include dielectric polymers and insulating oxides. This unique feature has stimulated growing interest in its applications for pollutant degradation, hydrogen peroxide production, methane oxidation, carbon dioxide reduction, and metal recovery. This review provides a systematic assessment from an integrated mechanism–material–engineering perspective. At its core, it constructs a unified mechanistic framework that establishes intrinsic logical connections across diverse applications based on common electron-transfer pathways. Furthermore, we systematically evaluate various material modification strategies designed to enhance CEC performance. Our analysis reveals that despite the broad applicability of CEC, the core bottleneck impeding its translation to practical implementation is the lack of standardized, quantitative performance reporting protocols. Current literature frequently omits critical quantitative metrics, including mechanical energy input, energy-normalized product yields, and long-term catalyst stability under realistic operating conditions. While surveying typical application scenarios, this review critically dissects current limitations in the field, such as insufficient mechanistic verification techniques, challenges in controlling product selectivity, and constraints in reactor scale-up. Accordingly, we propose a set of standardized data-reporting guidelines and outline key future research directions—specifically, operando characterization, theory-guided material discovery, and process engineering optimization—aiming to advance CEC from proof-of-concept laboratory studies toward practical engineering applications in environmental remediation and energy conversion.

Prophages, which are temperate bacteriophages integrated into bacterial chromosomes, serve as pervasive but understudied regulators of microbial ecology in aquatic environments. While they confer benefits such as enhanced virulence, stress resistance, and metabolic flexibility during lysogeny, environmental stressors can induce their lytic cycle, culminating in host cell lysis and phage dispersal. This review synthesizes current knowledge on prophage identification methodologies, environmental distribution patterns across diverse aquatic habitats (marine, freshwater, and wastewater systems), and their diverse roles in modulating environmental processes. Activation triggers and molecular pathways are systematically analyzed, alongside an assessment of their impacts on 1) biogeochemical cycling of C, N, P, and S; 2) dual regulation of biofilm dynamics; and 3) the dissemination and persistence of antibiotic resistance genes. The potential use of prophage derived endolysins as biocontrol agents is also discussed. By pinpointing key knowledge gaps—including in situ quantification of prophage induction, connecting prophage activity to community level processes, and validation under environmentally relevant conditions—this review proposes an integrated framework and priority research directions for aquatic prophage research, with cautious consideration of applications for water quality management and public-health protection.

Perfluoroalkyl substances (PFASs) are globally concerning pollutants due to their persistence, bioaccumulation potential, and adverse human health effects. As a densely populated and industrially intensive region suffering complex water pollution, the Haihe River Basin (HRB) in China is a priority area for PFAS research. This study clarified the occurrence characteristics and bioaccumulation patterns of PFASs in the middle and lower reaches of the HRB, derived ambient water quality criteria (AWQC) for seven PFASs, and assessed the potential non-carcinogenic human health risks. PFOA was the dominant compound in surface water (mean: 35.84 ng/L), while PFOS was most abundant in biota (1.16 ng/g). Chemical properties (45.3%) and PFASs concentration in water (26.8%) were the primary drivers of bioaccumulation factor (BAF) variation. BAFs displayed a non-monotonic pattern across carbon chain lengths (C8 < C6 < C4 < C9 < C10). AWQC were derived across different age groups and exposure scenarios. The AWQC values followed a consistent order of PFHxS < PFOS < PFNA < PFDA < PFHxA < PFOA < PFBA. Children aged 2–6 yr were identified as the most sensitive population. Human health risk assessment revealed Mentougou region in Beijing as a spatial hotspot. Drinking water was the dominant exposure pathway for PFOA, whereas fish consumption was the main route for other PFASs. Notably, PFOA, PFHxA, and PFHxS posed potential non-carcinogenic risks (HQ > 1) under certain specific scenarios. The results of this study could support the development of water quality criteria and risk-based management strategies for PFASs in industrialized watersheds.