Chemical bioaccumulation, which links internal exposure to hazards, plays a crucial role in ecological and human health risk assessment. Traditional bioaccumulation evaluations rely on laboratory-simulated exposure experiments and field monitoring studies, facing limitations in high cost, time constraints, and ethical concerns. Mechanistic toxicokinetic (TK) models and data-driven quantitative structure-activity relationship (QSAR) approaches have emerged as efficient alternatives. The review synthesizes decades of progress in TK and QSAR models for bioaccumulation prediction of chemicals in aquatic organisms, encompassing theoretical foundations, mathematical equations, practical applications, and current research gaps. While traditional compartmental TK models provide simplicity, physiologically-based toxicokinetic (PBTK) models enhance accuracy by incorporating species-specific physiology and chemical-dependent biochemical parameters. Existing PBTK models are currently limited to 10 fish species and 133 chemicals across 29 categories, with applications focused on internal concentration dynamics predictions, cross-species extrapolation, in vitro to in vivo extrapolation, and toxicity integration. Major limitations include a taxonomic bias toward fish, inadequate contaminant coverage, oversimplified environmental parameterization, incomplete mechanistic representations, and parameter scarcity. QSAR models have evolved from linear regression to machine learning approaches, achieving superior prediction performance through enhancing molecular representations and incorporating advanced algorithms. Nonetheless, challenges remain in TK parameter prediction and high-quality data acquisition. The review offers valuable insights and methodological advancements to support chemical risk assessment.

Accurate prediction of methane (CH4) emissions from agricultural lands, particularly rice paddies, is essential for effective climate change mitigation. Although current models capture broad emission trends, they often struggle to represent the complex interactions among the processes that govern CH4 production, oxidation, transport, and release. These challenges arise from multiple interconnected factors, including dynamic microbial communities with diverse metabolic pathways; fluctuating substrate availability shaped by rice management practices; and several transport mechanisms, such as diffusion, ebullition, and plant-mediated pathways, that are difficult to parameterize and scale. This review examines four interconnected dimensions of CH4 modeling: (a) how major CH4-related processes are conceptualized in existing models; (b) the quantitative performance of widely used CH4 models in rice systems; (c) the key limitations and challenges that constrain process-based CH4 simulations; and (d) opportunities for model improvement. Across these dimensions, the review provides an in-depth synthesis of the key biogeochemical and rice crop processes, including redox dynamics, substrate supply, microbial activity, CH4 production and oxidation, transport mechanisms, and rice plant–root–soil interactions. We argue that discrepancies between modeled and observed CH4 emissions arise not only from model assumptions and structural limitations but also from the inherent complexity of the system and limited data available for model development and evaluation. To enhance predictive accuracy, we highlight the need for improved representation of microbial processes, soil biogeochemistry, plant–soil interactions, and scaling approaches. Overall, this review provides an integrated perspective to guide the development of more advanced CH4 modeling tools for rice agricultural systems.

Global greenhouse effect and the increase of CO2 concentration in the atmosphere make harmful cyanobacterial blooms occur frequently. Understanding the inherent laws and influencing factors of cyanobacterial blooms is the key to hinder their development and maturity. Previous studies have focused on limiting the development of cyanobacteria by changing external environmental factors, ignoring the internal factors among microorganisms in the cyanobacteria bloom. Based on the ecological regulation strategies aimed at regulating the life activities of cyanobacteria and the succession of cyanobacterial blooms, we discuss the non-negligible role of quorum sensing in the formation of cyanobacterial blooms. The promo­tion effect of QS on the growth and development and competitive advantage phenotype of pure cyanobacteria was analyzed, and the potential influence of QS as an internal driving force for community succession of cyanobacteria was reasonably speculated. Although there are few studies on the regulation of QS as a control strategy for algal blooms. Here, we provide detailed information on the possible effects of QS on cyanobacteria and on the actual cyanobacterial bloom community, and the importance of QS in the formation of cyanobacterial blooms was emphasized. In addition, the previous studies on cyanobacterial QS are critically analyzed, the puzzling problems in these studies are put forward, and more perfect suggestions for future work are provided.

Chain elongation is an emerging bioprocess for converting diverse organic wastes into medium-chain carboxylates (MCCs) with high economic value and applications in fuels, antimicrobials, and food additives. This review integrates recent progress on metabolic mechanisms, microbial ecology, and process engineering strategies that promote efficient MCC synthesis. The effects of strict anaerobic and microaerobic conditions on ethanol- and lactate- driven reverse β oxidation are examined, alongside key enzymes and genes. The contributions of isolated bacterial strains, fungi, and open-culture system are compared, with emphasis on syntrophic interactions and substrate conversion efficiency. Process stability and competition pathways, as well as enhancements in interspecies electron transfer, are discussed carefully. In-line product extraction, particularly hollow fiber membrane liquid-liquid extraction, is highlighted for alleviating product inhibition. In the future, chain elongation can be further developed for waste valorization in a circular bioeconomy.

Carbohydrates are essential nutrients that serve as primary energy sources and structural components in living organisms. However, excessive consumption of conventional sugars has been increasingly linked to global health burdens such as obesity, diabetes, and metabolic disorders, as well as environmental concerns including greenhouse gas emissions. d -Tagatose, a naturally occurring rare sugar, has attracted considerable attention due to its low caloric value, prebiotic effects, and anti-obesity and anti-diabetic properties. Recent breakthroughs in targeted chemo-enzymatic synthesis, combined with directed evolution and systems metabolic engineering, have enabled more efficient and scalable production routes. Concurrently, the valorization of agricultural and food processing wastes as alternative raw materials aligns with circular bioeconomy principles and enhances sustainability. This review provides a comprehensive overview of recent technical advances, benefits, and ongoing challenges in d-tagatose production. We also highlight emerging strategies to facilitate commercialization and position d-tagatose as a cornerstone of the next generation of health-promoting sweeteners.

Wastewater surveillance is increasingly conducted to monitor antimicrobial resistance (AMR) in human populations, with antibiotic resistance genes (ARGs) serving as key molecular markers. Quantification of select ARGs provides a practical and scalable approach but is limited by inconsistent and context-specific target selection that relies on regional relevance or regulatory guidance rather than systematic selection strategies. Based on a global ARG dataset of 757 wastewater samples from 101 countries, this study establishes a systematic, multi-dimensional framework for indicator ARG selection that integrates global prevalence, regional differentiation, and clinical relevance. The framework establishes tiered indicator panels, that is, minimum, standard, and comprehensive, linking target selection to appropriate analytical platforms and resource capacities, thereby providing practical guidance for AMR wastewater surveillance. Global prevalence was assessed through the identification of core ARGs, which were consistently detected at high abundance and frequency across different regions worldwide. Regional differentiation was examined using multiple algorithms to identify consensus ARGs that drive interregional variation. Clinically relevant ARGs were selected based on their coverage of major drug classes and association with mobile genetic elements. This systematic yet flexible framework supports indicator ARG selection can be tailored to wastewater surveillance objectives by balancing analytical feasibility with epidemiological value.

Microbially driven anaerobic digestion (AD) is a key technology for energy recovery from biowaste. As critical regulators of microbial communication, quorum sensing (QS) and quorum quenching (QQ) impact AD by shaping microbial community structure and coordinating trophic-level metabolic interactions. However, their underlying mechanisms remain a “black box”, posing a significant barrier to process optimization and engineered control. This review deciphers the QS and QQ regulatory mechanisms in AD, focusing on signaling networks, environmental responsiveness, and microbial ecological functions. As current studies on QS/QQ in full-scale AD remain scarce, this review primarily draws on data from laboratory-scale reactors. First, we systematically mapped signaling molecule distribution in both liquid and solid phases across 21 anaerobic digesters, revealing that solid-phase matrices generally served as hotspots for acyl-homoserine lactone accumulation. Subsequently, the molecular mechanisms underpinning the transduction cascades of QS and QQ were dissected, including signal recognition, transmission, and interception. Furthermore, the dynamic responses of QS to environmental factors were comprehensively evaluated, together with their strong associations with microbial ecological functions and process stability. The regulatory roles of QS/QQ in extracellular polymeric substances synthesis, microbial spatial organization, metabolic pathway optimization, system robustness, and antibiotic resistance gene dissemination were also reviewed. Finally, challenges and prospects were discussed, including elucidating diverse signaling molecules roles, mapping QS/QQ signaling to metabolic pathways, and assessing long-term stability and ecological risks of QS/QQ strategies in engineering. This review offers a strategic reference for precisely regulating microbial metabolic networks and mitigating ecological risks in anaerobic digesters via signal transduction.

The accumulation of nitrates in water bodies caused by human activities poses a serious threat to human health and aquatic ecosystems. Electrocatalytic nitrate reduction reaction (eNO3RR), as a promising green process, can convert nitrate (NO3 −) into high-value ammonia (NH3), achieving the goal of “turning waste into resources”. However, eNO3RR is a significantly complex process involving multiple influencing factors. Herein, we critically review the fundamental principles of NO3 − reduction and selective NH3 synthesis in eNO3RR. The cathode engineering design for the NH3 generation by eNO3RR is systematically summarized, including a comparative analysis of precursor materials, such as precious metals, transition metals, and nonmetals. Moreover, the critical roles of reactor configuration, initial NO3 - concentration, pH conditions, and competitive ions in determining the selectivity and yield of NH3 from NO3 − reduction are thoroughly analyzed. This review also evaluates the research on efficient and compatible ammonia recovery technologies, addressing the core post-reaction processing gap in the field. Finally, techno-economic assessments and key challenges of eNO3RR are synthesized to examine the industrial potential and further implementation prospects.

The rapid expansion of global aquaculture, which is now a major source of aquatic products comparable to capture fisheries, is accompanied by significant environmental challenges. Among these challenges, mercury (Hg) and its neurotoxic form, methylmercury (MeHg), present serious threats to product safety and human health, necessitating urgent intervention. This review systematically synthesizes the current knowledge of Hg dynamics in aquaculture systems, which involve diverse exogenous and endogenous inputs, as well as complex multimedia/interface transfers and transformations. We detail Hg accumulation in water, sediments, and farmed organisms and elaborate on key processes such as adsorption–desorption, reduction, and competing methylation and demethylation pathways. A central focus is elucidating the mechanisms governing net MeHg production, encompassing abiotic pathways mediated by organic matter and antibiotics, microbial methylation/demethylation, and the roles of benthic organisms. Our synthesis highlights the pivotal yet dual roles of organic matter in regulating Hg (bio)availability and microbial activity. Its interplay with antibiotics and benthic bioturbation ultimately dictates the net MeHg outcome. Finally, we identify critical knowledge gaps and propose future research priorities, including synchronized and species-specific monitoring, advanced source-apportionment models, and mechanistic studies that integrate molecular-scale characterization of aquaculture-derived organic matter with the impacts of antibiotics and benthic communities. By providing a mechanistic framework for assessing MeHg risks, this review aims to guide actionable strategies and support the sustainable development of this vital food sector.

Fire retardants are widely used in buildings to protect life and property by mitigating fire hazards. Most fire retardants contain halogen elements, but their use is currently restricted to electronic products because of their negative environmental and health impacts. Moreover, although growing fire safety requirements for building materials have strengthened the demand for fire retardants, it is expected that halogen-containing materials will be restricted in various fields in the near future. Therefore, the construction industry and scientific community must develop sustainable halogen-free fire retardants (HFFRs). However, no clear direction for achieving these systems has yet been determined. An overview is provided of HFFR applications in the manufacturing of interior building materials such as wood, polymers, and metals. Recent advancements in the HFFRs for building applications and recycling approaches are discussed. The role of HFFR recycling in enhancing the sustainability of building materials is highlighted. The challenges of the current HFFR recycling methods and directions for addressing these challenges are also discussed. Strategies are proposed for recycling wood, polymers, and metal building materials, highlighting the practical implementation and scalability of these strategies for sustainable building applications. Finally, end-of-life strategies to enhance HFFR sustainability in building materials are proposed, with practical examples of industrial applications in construction, demonstrating the potential of applying these methods. This study aims to drive the development of more sustainable HFFRs, contributing to safer and more sustainable buildings.