Microbes from Different Soil Regions Play Distinct Roles in the Processing of Aquatic Dissolved Organic Matter.

Soil harbors abundant bacteria and viruses that can be delivered into water environments and alter aquatic ecology. However, the mechanisms by which the intruded soil microbes mediate the turnover of dissolved organic matter (DOM) in waters are unknown. Here, we prepared bacterial and phage-enriched inocula from the northern high-humic-composition (NHHS) and southern low-humic-composition (SLHS) soils in China, and investigated their roles in aquatic DOM transformation via microcosm experiments.

Reduced Cytochrome c: Exploring Its Promoting Function in Synergistic Denitrification by Pseudomonas sp. JM-7 and Thiobacillus denitrificans.

Excessive accumulation of nitrate in natural ecosystems can lead to eutrophication of water bodies, resulting in environmental impacts such as algal blooms and red tides that pose serious threats to environmental and human health. Autotrophic denitrification is a resource-efficient biological nitrogen removal technology, but the slow growth and low electron transfer efficiency of autotrophic denitrifiers limit their practical application. In this study, the heterotrophic denitrifying bacterium Pseudomonas sp.

Nanonet trapping for effective removal of nanoplastics by iron coagulation.

Nanoplastics (NPs) are emerging aqueous pollutants, posing risks to drinking water safety and human health. However, conventional coagulants, widely employed in water treatment plants globally, are ineffective at removing NPs. Here, we present an in-situ Fe(III) method based on the simultaneous use of Fe(II) coagulant and an oxidant to enhance conventional coagulation by altering the nanostructure of Fe-based precipitates in flocs for efficient NP removal.

Overlooked influence of phosphate on the performance of a dual membrane process with coagulation pretreatment.

The coagulation-ultrafiltration-nanofiltration (CUF-NF) treatment system is a promising approach for water treatment. However, the effects of phosphate on this system remain inadequately understood. In this study bench scale tests were conducted with both aluminium and iron salts using jar testing and membrane filtration, and a range of phosphate doses.

Constructing S/N-vacancy-and Co/Mo-bimetallic-catalysts for tetracycline degradation through peroxymonosulfate activation: evolution of active substance.

Regulation of the types and content of reactive oxygen species (ROS) in advanced oxidation processes (AOPs) is regarded as a challenging task. Herein, the features of sulfur-vacancy (Sv) and nitrogen-vacancy (Nv), and cobalt (Co)/molybdenum (Mo)-bimetallic constituents were simultaneously incorporated into a novel Co-N@MoS-COOH catalyst through a simple hydrothermal calcination method. The adsorption of oxygen (O) and peroxymonosulfate (PMS) was promoted by Sv/Nv, whereby the generation of superoxide radical (O·) and singlet oxygen (O) species was induced, and the energy barrier for the formation of high-valent cobalt-oxo species (Co(IV)=O) was reduced.

Carbon-mineral composite design for microwave-assisted degradation of organic contaminants.

Microwave (MW)-assisted catalytic oxidation with mineral-carbon composites is a potentially promising method for treating organic pollutants, but the underlying mechanisms involving varying mineral/carbon species remain unclear. To address this, we regulated the mineral and carbon speciation in the MW-assisted synthesis of CuFe-biochar composites by varying pyrolysis conditions and evaluated their roles in the MW-assisted generation of reactive oxygen species. The presence of CuFe-biochar composites significantly promoted the generation of •O and •OH radicals with HO, with an increased removal efficiency of two organic dyes as an example for real-time image visualization in the MW reactor, Acid Orange 7 and Malachite Green (up to 97.

Understanding the risk of enhanced particle penetration into slow sand filter beds when using underwater skimming techniques.

This study evaluated abiotic slow sand filters (SSFs) to understand the risk of particle penetration during underwater skimming (UWS), focusing on clogging, headloss development, and particle breakthrough. Pilot-scale filters containing clean sand were challenged with dispersed kaolin particles to simulate surface accumulation, and the sand surface was agitated to mimic UWS procedures. The study was undertaken with no maturation period to consider the worst-case scenario corresponding to the period just after filter skimming.

Deciphering membrane biofouling induced by micro-/nano-plastics in nanofiltration: Metagenomic insights and spacer-driven mitigations.

Nanofiltration (NF) is an effective process for micro-/nano-plastics (MNPs) interception, but the impact of accumulated MNPs on the microbial community structure and metabolic pathways of biofilms on NF membranes remains unclear. This provides uncertainty with respect to membrane biofouling behavior and the risks to efficient NF operations. In this study, the size-dependent (20 nm-25 μm) and concentration-dependent (0.

The nanoscale explanation of metal cations differences in enhancing the Fe(III) coagulation performance.

Coagulation is a widely applied and important process for water treatment, and the development of improved coagulation reagents continues to be a practical objective. However, mechanisms guiding the development of composite coagulants remain insufficiently understood. In addressing this deficiency, this study has investigated the enhancement of conventional Fe(III) coagulation by composite coagulants that incorporate an additional metal salt (Me: Ca²⁺, Al³⁺, Ti⁴⁺, Zr⁴⁺), focusing on the mechanistic roles that Me constituents play in Fe-based coagulation.

Enhanced methane production and biofouling mitigation by FeO nanoparticle-biochar composites in anaerobic membrane bioreactors.

Conductive materials present an innovative approach to enhancing methane production while facilitating sludge reduction and recovering resources in anaerobic digestion systems. However, the synergistic mechanisms by which composite materials influence the performance of anaerobic membrane bioreactor (AnMBR)-particularly in improving methane production and mitigating membrane fouling, remain underexplored. To address this, FeO nanoparticle-biochar composites (FeO-BC) were synthesized to enhance electrical conductivity and promote efficient electron transfer in AnMBRs system.

Evaluating the impact of underwater skimming on slow sand filter performance and operation.

Conventional cleaning of slow sand filters (SSFs) requires the beds to be drained before a layer of media and the Schmutzdecke are removed, called 'dry skimming' (DS), which can result in significant downtime. An alternative is proposed whereby the filter is skimmed whilst still submerged, called 'underwater skimming' (UWS). Previous attempts to avoid draining the bed have led to concerns about the risks of UWS in terms of headloss development, particle penetration, and microbial water quality.

The irreversible transformation of the molecular structure of humic acid during pH change and its effects on the formation of disinfection by-products.

Humic acid (HA) is an important component of natural organic matter, and understanding the nature and environmental behavior of HA is essential for advancing water treatment technologies and environmental remediation strategies. This study investigated the structural differences of HA at various pH values and whether the structure is reversible (whether the structure is similar when HA at different pH values is adjusted back to neutral compared to the original pH 7) by optical characteristics, hydrodynamic volume, fluorescence, infrared and circular dichroism spectroscopy. After adjustment back to neutral, from prior exposure to different pH values (2-12), the results showed an irreversible behavior of HA.

Per- and polyfluoroalkyl substances (PFAS) at low concentration improve coagulation efficiency but induce higher membrane fouling in drinking water treatment.

The presence of per- and polyfluoroalkyl substances (PFAS) in surface water has been widely reported in recent years. Many techniques, e.g.

Predicting the impact of underwater skimming on dissolved oxygen consumption in slow sand filters for potable water treatment.

In a well-functioning slow sand filter (SSF), dissolved oxygen (DO) is crucial for enabling aerobic processes and microbiota growth. Given that DO supply is predominantly via the feed water, flow pauses (e.g.

Exploring the influence of aquatic phosphate on Fe floc dynamics in water treatment.

The formation of flocs is crucial in the coagulation process of water treatment. However, the nature of ligand exchange on the surface of primary nanoparticles (PNPs) during floc formation requires further investigation to enhance our understanding of the coagulation mechanism. Phosphate (P) is a ubiquitous nutrient ion in aquatic surface water, in this study, the impact of P on floc growth under different pH conditions were investigated.

Capabilities of Microbial Consortia from Disparate Environment Matrices in the Decomposition of Nature Organic Matter by Biofiltration.

Dissolved organic matter (DOM) plays a pivotal role in drinking water treatment, influencing the performance of unit processes and final water quality (e.g. disinfection byproduct risk).

Surface Microstructure Drives Biofilm Formation and Biofouling of Graphene Oxide Membranes in Practical Water Treatment.

Significant progress has been made previously in the research and development of graphene oxide (GO) membranes for water purification, but their biofouling behavior remains poorly understood. In this study, we investigated the biofilm formation and biofouling of GO membranes with different surface microstructures in the context of filtering natural surface water and for an extended operation period (110 days). The results showed that the relatively hydrophilic and smooth Fe(OH)/GO membrane shaped a thin and spatially heterogeneous biofilm with high stable flux.

Pulsed electro-catalysis enables effective conversion of low-concentration nitrate to ammonia over CuO@Pd tandem catalyst.

Electro-catalytic conversion of nitrate (NO) to ammonia (NH) via the Nitrate Reduction to Ammonia (NORA) process represents a promising strategy for both ammonia synthesis and environmental remediation. Despite its potential, the efficiency of low-concentration NORA is often hindered by mass transfer limitations, competing byproducts (N and NO), and side reactions such as hydrogen evolution. This study introduces a novel pulsed electro-synthesis technique that alternates the potential to periodically accumulate and transform NO intermediates near a Cu2O@Pd electrode, enhancing the NORA process.

The application of chitosan quaternary ammonium salt to replace polymeric aluminum ferric chloride for sewage sludge dewatering.

Inorganic coagulants such as poly aluminum ferric chloride (Al/Fe) are applied conventionally to sewage sludge dewatering and can be retained in the sludge cake, causing its conductivity to increase and generate secondary pollution. To reduce these disadvantages, there is a need to develop alternative, more sustainable chemicals as substitutes for conventional inorganic coagulants. In the present investigation, the application of a polymeric chitosan quaternary ammonium salt (CQAS) is explored as a complete, or partial, replacement for Al/Fe in the context of sludge dewatering processes.

Excessive Ozonation Stress Triggers Severe Membrane Biofilm Accumulation and Fouling.

The established benefits of ozone on microbial pathogen inactivation, natural organic matter degradation, and inorganic/organic contaminant oxidation have favored its application in drinking water treatment. However, viable bacteria are still present after the ozonation of raw water, bringing a potential risk to membrane filtration systems in terms of biofilm accumulation and fouling. In this study, we shed light on the role of the specific ozone dose (0.

Bioinspired stormwater control measure for the enhanced removal of truly dissolved polycyclic aromatic hydrocarbons and heavy metals from urban runoff.

Stormwater harvesting (SWH) addresses the UN's Sustainable Development Goals (SDGs). Conventional stormwater control measures (SCMs) effectively remove particulate and colloidal contaminants from urban runoff; however, they fail to retain dissolved contaminants, particularly substances of concern like polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs), thereby hindering the SWH applicability. Here, inspired by protein folding in nature, we reported a novel biomimetic SCM for the efficient removal of dissolved PAHs and HMs from urban runoff.

Uncovering the neglected role of anions in trivalent cation-based coagulation processes.

Coagulation efficiency is heavily contingent upon a profound comprehension of the underlying mechanisms, facilitated by the evolution of coagulation theory. However, the role of anions, prevalent components in raw and wastewaters, has been relatively overlooked in this context. To address this gap, this study has investigated the impact of three common anions (i.