The synergistic effect of radical and non-radical processes on the dephosphorization of dimethoate by vacuum ultraviolet: The overlooked roles of singlet oxygen atom and high-energy excited state.

Organophosphorus pesticides are extensively utilized worldwide, but their incomplete dephosphorization poses significant environmental risks. This study investigates the dephosphorization of dimethoate (DMT), a representative organophosphorus pesticide, using a vacuum ultraviolet system. Surprisingly, in addition to hydroxyl radicals (OH), non-radical processes such as photoexcitation and singlet oxygen atoms (O(D)) exert more significant effects on DMT dephosphorization.

Effects of mono- and multicomponent nonaqueous-phase liquid on the migration and retention of pollutant-degrading bacteria in porous media.

The successful implementation of in-situ bioremediation of nonaqueous-phase liquid (NAPL) contamination in soil-groundwater systems is greatly influenced by the migration performance of NAPL-degrading bacteria. However, the impact and mechanisms of NAPL on the migration/retention of pollutant-degrading bacteria remain unclear. This study investigated the migration/retention performance of A.

Impact of freeze-thaw cycles on the remobilization behaviors of microplastics in natural soils.

Freeze-thaw (FT) cycle would greatly influence the fate of plastic particles (one of emerging contaminants with great concerns) in soils, yet its impacts and mechanisms remain unclear. The vertical migration/release behaviors of plastic particles (with diameters of 0.2 μm and 1 μm) in two natural soils and one model soil (i.

Oxygen vacancy-dependent synergistic disinfection of antibiotic-resistant bacteria by BiOBr nanoflower induced HO activation.

Antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs) pose a significant threat to both ecosystems and human health. Owing to the excellent catalytic activity, eco-safety, and convenience for defect engineering, BiOBr with oxygen vacancies (OVs) of different density thus were fabricated and employed to activate HO for ARB disinfection/ARGs degradation in present study. We found that BiOBr with OVs of appropriate density induced via ethanol reduction (BOB-E) could effectively activate HO, achieving excellent ARB disinfection and ARGs degradation efficiency.

Rigid covalent organic frameworks with thiazole linkage to boost oxygen activation for photocatalytic water purification.

Owing to their capability to produce reactive oxygen species (ROS) under solar irradiation, covalent organic frameworks (COFs) with pre-designable structure and unique architectures show great potentials for water purification. However, the sluggish charge separation, inefficient oxygen activation and poor structure stability in COFs restrict their practical applications to decontaminate water. Herein, via a facile one-pot synthetic strategy, we show the direct conversion of reversible imine linkage into rigid thiazole linkage can adjust the π-conjugation and local charge polarization of skeleton to boost the exciton dissociation on COFs.

Functional group-specific reduction of Cr(VI) by low molecular weight organic acids in frozen solution: Kinetics, mechanism and DFT calculation.

Low molecular weight organic acids (LMWOA) are commonly present in natural water and play a pivotal role in the reduction of Cr(VI). In frozen solutions, the efficiency of Cr(VI) reduction is significantly enhanced due to the freezing concentration effect. However, this facilitation is found to be contingent upon the functional groups of LMWOA in this study.

Starvation Process Would Induce Different Bacterial Mobilities and Attachment Performances in Porous Media without and with Nutrients on Surfaces.

The influence and mechanisms of starvation on the bacterial mobile performance in porous media with different nutrition conditions are not well understood. The present study systematically investigated the impacts of starvation on the mobility and attachment of both Gram-negative and Gram-positive strains in porous media without and with nutrients on surfaces in both simulated and real water samples. We found that regardless of strain types and water chemistries, starvation would greatly inhibit bacterial attachment onto bare porous media without nutrients yet could significantly enhance cell attachment onto porous media with nutrients on their surfaces.

Elimination of representative antibiotic-resistant bacteria, antibiotic resistance genes and ciprofloxacin from water via photoactivation of periodate using FeS.

The propagation of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) induced by the release of antibiotics poses great threats to ecological safety and human health. In this study, periodate (PI)/FeS/simulated sunlight (SSL) system was employed to remove representative ARB, ARGs and antibiotics in water. 1 × 10 CFU mL of gentamycin-resistant Escherichia coli was effectively disinfected below limit of detection in PI/FeS/SSL system under different water matrix and in real water samples.

Simultaneous inactivation of Microcystis aeruginosa and degradation of microcystin-LR in water by activation of periodate with sunlight.

Harmful algal blooms pose tremendous threats to ecological safety and human health. In this study, simulated solar light (SSL) irradiation was used to activate periodate (PI) for the inactivation of Microcystis aeruginosa and degradation of microcystin-LR (MC-LR). We found that PI-SSL system could effectively inactivate 5 × 10 cells·mL algal cells below the limit of detection within 180 min.

Emerging contaminants: A One Health perspective.

Environmental pollution is escalating due to rapid global development that often prioritizes human needs over planetary health. Despite global efforts to mitigate legacy pollutants, the continuous introduction of new substances remains a major threat to both people and the planet. In response, global initiatives are focusing on risk assessment and regulation of emerging contaminants, as demonstrated by the ongoing efforts to establish the UN's Intergovernmental Science-Policy Panel on Chemicals, Waste, and Pollution Prevention.

Effects of arsenic on the transport and attachment of microplastics in porous media.

Understanding the impact of arsenic (As(III), inorganic pollutant widely present in natural environments) on microplastics (MPs, one type of emerging contaminants) mobility is essential to predict MPs fate and distribution in soil-groundwater systems, yet relevant research is lacking. This study explored the effects of As(III) copresent in suspensions (0.05, 0.

Transport and release behaviors of PFOA in saturated and unsaturated porous media with biochar amendment.

The widespread usage of perfluorooctanoic acid (PFOA) in daily consumer products and its high mobility in porous media have resulted in ubiquitous contamination of PFOA in the natural environment. Developing techniques to immobilize and inhibit the transport of PFOA thus is critical to reduce its potential risks. In present study, biochar, one type of environmental-friendly material produced from cellulose, was utilized in porous media to test its addition on inhibiting the transport and release of PFOA before and after aging process.

Efficient Photosynthesis of Hydrogen Peroxide by Cyano-Containing Covalent Organic Frameworks from Water, Air and Sunlight.

The insufficient exciton (e -h pair) separation/transfer and sluggish two-electron water oxidation are two main factors limiting the H O photosynthetic efficiency of covalent organic frameworks (COFs) photocatalysts. Herein, we present an alternative strategy to simultaneously facilitate exciton separation/transfer and reduce the energy barrier of two-electron water oxidation in COFs via a dicyano functionalization. The in situ characterization and theoretical calculations reveal that the dicyano functionalization improves the amount of charge transfer channels between donor and acceptor units from two in COF-0CN without cyano functionalization to three in COF-1CN with mono-cyano functionalization and four in COF-2CN with dicyano functionalization, leading to the highest separation/transfer efficiency in COF-2CN.

Efficient As(III) removal from water by ZrO modified covalent organic framework under visible light irradiation.

Adsorption-oxidation is a promising technique to decontaminate As(III) polluted water. In present study, ZrO-modified covalent organic framework (ZrO-COF) was fabricated and used to remove arsenic from water under visible light irradiation. The results showed that ZrO-COF (0.

Is crystalline chromium phosphate environmentally stable? A study on the formation, dissolution and oxidation risk of CrPO·6HO.

Hexavalent chromium (Cr(VI)) contamination in soil and groundwater is usually remediated via reduction techniques. The formation of crystalline chromium phosphate (CrPO·6 HO) occurs as a byproduct during Cr(VI) remediation processes in the presence of phosphate, yet its stability in the environment has received limited attention. In this study, the formation conditions, structure, properties, and risks associated with the dissolution and oxidation of CrPO·6 HO were comprehensively assessed.

Sulfite Poses a Risk of Hexavalent Chromium Rebound in Vadose Zone: A Challenge of the Stability of CrFe(OH).

Cr(VI) rebound is the primary risk associated with the reduction remediation of Cr(VI)-contaminated soil. The potential impact of sulfites, which can be produced by microbial activities or originate from sulfur-containing remediation agents, on the Cr(VI) rebound in the vadose zone has been overlooked. When sulfites are present, the stability of CrFe(OH) is compromised and significantly inferior to that of Cr(OH), as demonstrated in this paper.

Boosting Exciton Dissociation and Charge Transfer in Triazole-Based Covalent Organic Frameworks by Increasing the Donor Unit from One to Two for the Efficient Photocatalytic Elimination of Emerging Contaminants.

As novel photocatalysts, covalent organic frameworks (COFs) have potential for water purification. Insufficient exciton dissociation and low charge mobility in COFs yet restricted their photocatalytic activity. Excitonic dissociation and charge transfer in COFs could be optimized via regulating the donor-acceptor (D-A) interactions through adjusting the number of donor units within COFs, yet relevant research is lacking.

Covalent organic frameworks for direct photosynthesis of hydrogen peroxide from water, air and sunlight.

Solar-driven photosynthesis is a sustainable process for the production of hydrogen peroxide, the efficiency of which is plagued by side reactions. Metal-free covalent organic frameworks (COFs) that can form suitable intermediates and inhibit side reactions show great promise to photo-synthesize HO. However, the insufficient formation and separation/transfer of photogenerated charges in such materials restricts the efficiency of HO production.

Effects of Antibiotic Resistance Genes and Antibiotics on the Transport and Deposition Behaviors of Bacteria in Porous Media.

Antibiotics present in the natural environment would induce the generation of antibiotic-resistant bacteria (ARB), causing great environmental risks. The effects of antibiotic resistance genes (ARGs) and antibiotics on bacterial transport/deposition in porous media yet are unclear. By using without ARGs as antibiotic-susceptible bacteria (ASB) and their corresponding isogenic mutants with ARGs in plasmids as ARB, the effects of ARGs and antibiotics on bacterial transport in porous media were examined under different conditions (1-4 m/d flow rates and 5-100 mM NaCl solutions).

The overlooked role of UV induced high-energy excited states in the dephosphorization of organophosphorus pesticide by VUV/persulfate.

Vacuum ultraviolet (VUV) based advanced oxidation processes (AOPs) recently attracted widespread interests. However, the role of UV in VUV is only considered to be generating a series of active species, while the effect of photoexcitation has long been overlooked. In this work, the role of UV induced high-energy excited state for the dephosphorization of organophosphorus pesticides was studied using malathion as a model.

Freeze-thaw treatment of bacteria significantly affects bacterial transport behaviors in both saturated and unsaturated porous media: Deep investigation the roles of flagella and extracellular polymeric substances.

The effects of freeze-thaw (FT) treatment and mechanisms on bacteria transport/retention in porous media with different moisture contents remain unclear. The transport/retention behaviors of bacteria with different FT treatment cycles (0, 1, and 3) in sand columns with different moisture contents (100 %, 90 %, 60 %, and 30 %) in NaCl solutions (10 and 100 mM) thus were investigated. Regardless of moisture content and solution chemistry, FT treatment increased bacteria deposition in sand columns, consistent with the results of QCM-D and visible parallel plate flow chamber (PPFC) systems.

Cotransport of different electrically charged microplastics with PFOA in saturated porous media.

The fate and transport behavior of microplastics (MPs), emerging colloidal contaminant ubiquitous in natural environments, would be greatly affected by other copresent pollutants. PFOA (emerging surfactant pollutant) would interact with MPs after encounter with them in natural environments, which could alter the transport behavior of both pollutants. Relevant knowledge is still lacking, affecting accurate prediction the fate and distribution of these two emerging contaminants in natural porous media.

Efficient peroxymonosulfate activation by magnetic MoS@FeO for rapid degradation of free DNA bases and antibiotic resistance genes.

Antibiotic resistance genes (ARGs) have become as emerging contaminant with great concerns worldwide due to their threats to human health. It is thus urgent to develop techniques to degrade ARGs in water. In this study, MoS@FeO (MF) particles were fabricated and used to activate peroxymonosulfate (PMS) for the degradation of four types of free DNA bases (T, A, C, and G, major components of ARGs) and ARGs.

Influence of flagella and their property on the initial attachment behaviors of bacteria onto plastics.

Flagella and their property would influence the initial attachment of bacteria onto plastics, yet their impacts have not been investigated. In present study, four types of E. coli with or without flagella as well as with normal or sticky flagella were utilized to investigate the effects of flagella and their property on the initial attachment behaviors of bacteria onto six types of plastics in freshwater systems.