A comprehensive guideline for hybrid modeling of engineered microbial processes.

Microbial processes have been extensively engineered to remove contaminants and recover value-added products. Despite their practical significance, these processes present unique challenges in both design and operation due to the inherent variability and complexity of microbial populations and communities. As the driving force of engineered microbial systems, the activity of microbial populations and the structure of their communities remain difficult to control and model.

Trivalent Vanadium Precipitation in Siderite-Dependent Vanadate Bioreduction by Denitrifying Bacteria in Groundwater.

Vanadium (V) is a redox-sensitive metal with three valence states (+3, +4, +5) in Earth's surficial environment. The microbially mediated transformation of hazardous vanadate [V(V)] plays a pivotal role in V geochemistry and detoxification. Tetravalent V [V(IV)] is the most common species resulting from V(V) bioreduction, but it is susceptible to reoxidation and release during redox fluctuation.

TP-Transformer: An Interpretable Model for Predicting the Transformation Pathways of Organic Pollutants in Chemical Oxidation Processes.

Chemical oxidation is pivotal in remediating organic pollutants in aquatic systems; however, it frequently yields transformation products (TPs) with potential toxicological profiles surpassing those of the parent pollutants. Comprehensive identification of these TPs is imperative for environmental risk assessment and optimization of oxidation methodologies. Traditional experimental approaches for TP elucidation are often hindered by substantial financial and technical constraints, limiting their applicability in high-throughput scenarios.

Methodology Discrepancy and Data Comparability of Greenhouse Gas Monitoring from Water Resource Recovery Facilities.

Wastewater is a major source of methane (CH) and nitrous oxide (NO), highlighting the need for accurate monitoring to develop accurate inventories and effective mitigation strategies. This study systematically evaluates current measurement methodologies, emphasizing significant variability across different techniques that contribute to reporting discrepancies. Bottom-up approaches, such as flux chambers and liquid sensors, dominate unit-level data collection, while emerging top-down methods provide plant-level-integrated estimates.

Physical Aging of Poly(methyl methacrylate) Brushes and Spin-Coated Films.

While there is significant attention aimed at understanding how one-dimensional confinement and chain confirmations can impact the glass transition temperature () of polymer films, there remains a limited focus on similar effects on sub- processes, notably, structural relaxation. Using spectroscopic ellipsometry, we investigated the combined influence of confinement and molecular packing on and physical aging, i.e.

Understanding the Global Distribution of Groundwater Sulfate and Assessing Population at Risk.

Besides sulfate-induced diarrhea, recent studies have emphasized that groundwater sulfate drives the release of arsenic in groundwater and accelerates water pipeline corrosion. Despite its impact on public health and urban infrastructure, sulfate has been overlooked in water supply research. Here, we used a random forest model to develop a 1 km global map depicting the probability of sulfate exceeding 250 mg/L in groundwater based on the World Health Organization's guidelines.

Water Resource Recovery Facilities Empower the Electrolytic Hydrogen Economy.

The global transition to net-zero emissions necessitates the integration of clean hydrogen as a key solution. To facilitate the required expansion of clean hydrogen production, sustainable water sources are required to support the electrolysis process. Utilizing nontraditional water sources such as water resource recovery facility (WRRF) effluents could potentially alleviate the water constraints and create cobenefits, but the real-world feasibility has not been explored in depth.

Concentrated C Alcohol Production Enabled by Post-Intermediate Modulation and Augmented CO Adsorption in CO Electrolysis.

The electrocatalytic synthesis of multicarbon products from CO/CO feedstock represents a sustainable method for chemical production with a reduced carbon footprint. Traditional copper catalysts predominantly produce alkenes, but generating valuable and versatile C alcohols, especially high-energy-density C alcohols, has been challenging due to issues with selectivity, activity, and stability. Here, we present the construction of Ru-doped Cu nanowires that enhance the selectivity of -PrOH and C alcohols.

Pilot microbial electrolysis cell closes the hydrogen loop for hydrothermal wet waste conversion to jet fuel.

The global shift toward net-zero emissions necessitates resource recovery from wet waste. In this study, we demonstrate the first feasibility of combining pilot-scale microbial electrolytic cells (MECs) with hydrothermal liquefaction (HTL) for simultaneous post-hydrothermal liquefaction wastewater (PHW) treatment and efficient hydrogen (H₂) production to meet biocrude upgrading requirements. Long-term single reactor operation revealed that fixed anode potential enabled rapid startup, and low catholyte pH and high salinity were effective in suppression of cathodic methanogenesis and acetogenesis - resulting in high current density of 16.

Membrane electrolysis distillation for volatile fatty acids extraction from pH-neutral fermented wastewater.

Volatile fatty acids (VFAs) serve as building blocks for a wide range of chemicals, but it is difficult to extract VFAs from pH-neutral wastewater using evaporation methods because of the ionized form. This study presents a new membrane electrolysis distillation (MED) process that extracts VFAs from such fermentation solutions. MED uniquely integrates pH regulation and joule heating to facilitate the efficient evaporation of VFAs.

Machine Learning for Polymer Design to Enhance Pervaporation-Based Organic Recovery.

Pervaporation (PV) is an effective membrane separation process for organic dehydration, recovery, and upgrading. However, it is crucial to improve membrane materials beyond the current permeability-selectivity trade-off. In this research, we introduce machine learning (ML) models to identify high-potential polymers, greatly improving the efficiency and reducing cost compared to conventional trial-and-error approach.

Electrochemically coupled CH and CO consumption driven by microbial processes.

The chemical transformations of methane (CH) and carbon dioxide (CO) greenhouse gases typically have high energy barriers. Here we present an approach of strategic coupling of CH oxidation and CO reduction in a switched microbial process governed by redox cycling of iron minerals under temperate conditions. The presence of iron minerals leads to an obvious enhancement of carbon fixation, with the minerals acting as the electron acceptor for CH oxidation and the electron donor for CO reduction, facilitated by changes in the mineral structure.

Coupling Curvature and Hydrophobicity: A Counterintuitive Strategy for Efficient Electroreduction of Nitrate into Ammonia.

The electrochemical upcycling of nitrate (NO) to ammonia (NH) holds promise for synergizing both wastewater treatment and NH synthesis. Efficient stripping of gaseous products (NH, H, and N) from electrocatalysts is crucial for continuous and stable electrochemical reactions. This study evaluated a layered electrocatalyst structure using copper (Cu) dendrites to enable a high curvature and hydrophobicity and achieve a stratified liquid contact at the gas-liquid interface of the electrocatalyst layer.

Pumping and sliding of droplets steered by a hydrogel pattern for atmospheric water harvesting.

Atmospheric water harvesting is an emerging strategy for decentralized and potable water supplies. However, water nucleation and microdroplet coalescence on condensing surfaces often result in surface flooding owing to the lack of a sufficient directional driving force for shedding. Herein, inspired by the fascinating properties of lizards and catfish, we present a condensing surface with engineered hydrogel patterns that enable rapid and sustainable water harvesting through the directional pumping and drag-reduced sliding of water droplets.

H mediated mixed culture microbial electrosynthesis for high titer acetate production from CO.

Microbial electrosynthesis (MES) converts CO into value-added products such as volatile fatty acids (VFAs) with minimal energy use, but low production titer has limited scale-up and commercialization. Mediated electron transfer via H on the MES cathode has shown a higher conversion rate than the direct biofilm-based approach, as it is tunable via cathode potential control and accelerates electrosynthesis from CO. Here we report high acetate titers can be achieved via improved H supply by nickel foam decorated carbon felt cathode in mixed community MES systems.

Ca-Based Layered Double Hydroxides for Environmentally Sustainable Carbon Capture.

The process of carbon dioxide capture typically requires a large amount of energy for the separation of carbon dioxide from other gases, which has been a major barrier to the widespread deployment of carbon capture technologies. Innovation of carbon dioxide adsorbents is herein vital for the attainment of a sustainable carbon capture process. In this study, we investigated the electrified synthesis and rejuvenation of calcium-based layered double hydroxides (Ca-based LDHs) as solid adsorbents for CO.

Tough and Recyclable Phase-Separated Supramolecular Gels via a Dehydration-Hydration Cycle.

Hydrogels are compelling materials for emerging applications including soft robotics and autonomous sensing. Mechanical stability over an extensive range of environmental conditions and considerations of sustainability, both environmentally benign processing and end-of-life use, are enduring challenges. To make progress on these challenges, we designed a dehydration-hydration approach to transform soft and weak hydrogels into tough and recyclable supramolecular phase-separated gels (PSGs) using water as the only solvent.

Membrane Distillation-Crystallization for Sustainable Carbon Utilization and Storage.

Anthropogenic greenhouse gas emissions from power plants can be limited using postcombustion carbon dioxide capture by amine-based solvents. However, sustainable strategies for the simultaneous utilization and storage of carbon dioxide are limited. In this study, membrane distillation-crystallization is used to facilitate the controllable production of carbonate minerals directly from carbon dioxide-loaded amine solutions and waste materials such as fly ash residues and waste brines from desalination.

Machine Learning in Environmental Research: Common Pitfalls and Best Practices.

Machine learning (ML) is increasingly used in environmental research to process large data sets and decipher complex relationships between system variables. However, due to the lack of familiarity and methodological rigor, inadequate ML studies may lead to spurious conclusions. In this study, we synthesized literature analysis with our own experience and provided a tutorial-like compilation of common pitfalls along with best practice guidelines for environmental ML research.

Highly Selective Electrochemical Nitrate to Ammonia Conversion by Dispersed Ru in a Multielement Alloy Catalyst.

Electrochemical reduction of nitrate to ammonia (NH) converts an environmental pollutant to a critical nutrient. However, current electrochemical nitrate reduction operations based on monometallic and bimetallic catalysts are limited in NH selectivity and catalyst stability, especially in acidic environments. Meanwhile, catalysts with dispersed active sites generally exhibit a higher atomic utilization and distinct activity.