Aerosols play a critical role in Earth’s system, significantly influencing air quality, weather, and climate dynamics. Accurately modeling their effects is essential for advancing our understanding of the climate system and improving predictive capabilities for future climate scenarios. Despite significant progress in aerosol modeling, substantial challenges persist in representing their formation, properties, and interactions with climate and weather systems. This review synthesizes recent advances in aerosol formation modeling, with particular emphasis on (1) refined nucleation and growth mechanisms, and (2) the integration of satellite observations with machine learning techniques. Furthermore, it evaluates state-of-the-art representation of aerosol-radiation and aerosol-cloud interactions in global and regional models, while systematically identifying persistent uncertainties and ongoing challenges. The study emphasizes the need for future research that integrates global in-situ measurements with high-resolution satellite data and cutting-edge machine learning and modeling frameworks to enhance simulations of aerosol formation and their interactions with climate and weather systems. Ultimately, these efforts will reduce uncertainties in aerosol modeling and provide more reliable climate projections.
Biogas residue, also known as digestate, is the solid by-product of anaerobic digestion, rich in organic matter and nutrients. In China, various types of biogas residue display distinct physical, chemical, biological, and toxicological properties depending on their feedstock and treatment processes. Conventional disposal methods, such as landfilling, can result in nutrient loss and pose environmental risks. This review provides a comprehensive evaluation of the major resource recovery pathways for biogas residue: thermochemical transformation technologies (pyrolysis and hydrothermal carbonization) and composting. These processes offer sustainable solutions for converting biogas residue into value-added products, including biochar, compost, and hydrochar. Additionally, the review outlines future strategies for optimizing digestate management, with a focus on tailoring treatment approaches to specific residue types, streamlining processing chains, and integrating front-end production with back-end waste management. These recommendations aim to improve resource efficiency, mitigate environmental impacts, and promote sustainable development within the framework of a circular economy.
Enhancing the electrosynthesis of hydrogen peroxide (H2O2) (the two-electron oxygen reduction and 2e−ORR) is critical for decentralized and on-site H2O2 production. However, the high aeration energy consumption and serious side reactions in the 2e−ORR system have decreased its 2e−ORR performance, hindering its further application. Herein, we greatly reduced the aeration energy consumption using anode-produced O2 for the cathode 2e−ORR (anode-cathode coupling) and further decreased the hydrogen evolution reaction (HER) and H2O2 electroreduction by applying pulses. A flow-through reactor with narrow electrode gaps efficiently improves the utilization of anode-produced O2. It increased the effluent H2O2 concentration by 101.22% compared to non-coupled systems. In addition, pulsed electrolysis increased the effluent H2O2 concentration and current efficiency by 3.41 and 11.38 times, respectively. During the power-off period, the electrochemical reaction paused, whereas the O2 and H2O2 diffusion continued under the concentration gradient. These processes relieve the O2 shortage at the cathodes to decrease the HER and alleviate H2O2 accumulation at the cathodes, thus reducing its decomposition. Our results provide an easy and efficient way to improve H2O2 electrosynthesis performance.
As nanoplastics continue to accumulate in natural wetland ecosystems, it remains unclear whether and how the effects of nanoplastics on the emission of methane (CH4) and nitrous oxide (N2O). Here we constructed a simulated natural wetland and introduced polystyrene nanoplastics (PS-NPs) to investigate the effects and potential mechanisms on CH4 and N2O emissions. The results indicated that PS-NPs can increase CH4 emissions by 20% to 100% and N2O emissions by approximately 100%. Analysis of the microbial community and plant functional characteristics in soils showed that PS-NPs inhibited plant growth and photosynthesis, and weakened plant stress resistance. Changes in plant functional characteristics affect the oxygen production capacity and secretion content of plant roots, which further affect the microbial community structure and metabolic activity of rhizosphere soil, enhancing methanogenesis and denitrification processes during the carbon and nitrogen cycles, resulting in increased CH4 and N2O emissions. Therefore, the continuous accumulation of PS-NPs is an important factor in changing the carbon sink function of wetlands. This study underscores the importance of controlling plastics pollution for the emission of greenhouse gases.
Plant growth-promoting bacteria (PGPB) are recently acknowledged as an effective eco-friendly agent for plant growth, accumulation and remediation of cadmium (Cd). PGPB isolated from the hyperaccumulator Sedum alfredii Hance were beneficial to Cd phytoextraction by regulating photosynthetic system of Brassica juncea L. However, the intrinsic regulating mechanism of the photosystem and the related key genes and pathways remain unclear. Results of laser scanning confocal microscopy (LSCM) indicated that, for Sphingomonas sp. SaMR12 to successfully survive and colonize in B. juncea they must first invade the base of lateral roots. SaMR12 inoculation under 1 × 10−5 mol/L Cd significantly increased chlorophyll a contents by 71.98%, ETR by 27.96%, Fv/Fm by 14.17%, PS II by 27.96%, qN by 12.67%, and qL by 34.87%, accordingly, indicating that SaMR12 could ameliorate repressive effects by improving the acquisition efficiency of light energy in the chloroplasts, activating the photocatalytic abilities of PS II and the energy cycle of the photosynthetic reaction center. Furthermore, results of RNA sequencing combined with weighed gene co-expression network analysis (WGCNA) identified module ‘ME130’ with 227 genes and ‘ME157’ with 2208 genes were significantly associated with chlorophyll fluorescence parameters, molecular function of these candidate genes mainly categorized to catalytic activity (GO:0003824), binding (GO:0005488), and ATP-dependent activity (GO:0140657); and biological process of these genes mainly fall into cellular process (GO:0009987) and metabolic process (GO:0008152). This study extends the investigation into PGPB functional mechanisms towards Cd accumulation and simultaneously improves acknowledgments of microbe-plant interaction in mitigating contaminants to further guarantee soil health and food safety.
Activated carbon (AC) is a highly versatile adsorbent widely used in water and wastewater treatment due to its strong adsorption capabilities. However, conventional coal-derived AC has raised significant environmental concerns, necessitating the development of more sustainable alternatives such as pine-bark-derived adsorbents (PBAs). This study proposes a multi-criteria selection framework that integrates conventional physical and adsorption capacity-based evaluation with environmental sustainability considerations. By combining these criteria, the framework enabled the identification of adsorbents that offer optimal performance while minimizing their environmental impacts. Of the evaluated PBAs, that dual activation of both NaOH and HCl (PB-NH) was found to be the most effective option, with superior adsorption capacity and a lower environmental footprint. Life cycle assessment (LCA) was conducted using both mass-based and adsorption capacity-based functional units to comprehensively evaluate the sustainability of the PBAs. In addition to conventional midpoint impact categories, this study quantified the cumulative energy demand and endpoint impacts. This study also critically assessed the environmental impacts of AC activation using various physical and chemical strategies to benchmark PB-NH against alternative adsorbents, while a prospective scale-up LCA framework was employed to investigate the optimization of AC production at an industrial scale. Finally, end-of-life assessment was employed to determine the extent to which emissions can be mitigated using different disposal methods for the adsorbent. By combining experimental analysis with LCA modeling, this study provides a systematic and quantifiable approach for the development of sustainable adsorbents.
The globally concerning per- and polyfluoroalkyl substances (PFASs) were widely detected in the environment, yet their environmental occurrences and behaviors remain elusive in the grassland soils. In this study, the region-specific distributions, sources and potential ecological risk of 31 legacy and novel PFASs were investigated in 74 grassland soils from Xilingol League, China. The 20 out of 31 PFASs were detected with the detection frequencies > 50%, and the total concentrations of 31 PFASs were in the range of 263.7–16795.8 pg/g dry weight (d.w.). The novel PFASs were the dominant congeners, followed by legacy PFASs and PFAS precursors, indicating the widespread contamination of novel PFASs in the grassland soils. Elevated PFAS concentrations were detected in the soils adjacent to the industrial and urban areas. Industrial, fire-fighting and household activities, and long-range atmospheric transport were discovered as the main sources of PFASs in the grassland soils from Xilingol League. The calculated risk quotient values (< 0.01) only indicated the low ecological risk of 12 target PFASs in the grassland soils. Our work enriches the data of PFAS contamination in the grassland soils, which provides the critical reference for the implementation of Action Plan on Controlling New Pollutants in China.
The creation of effective and sustainable wastewater treatment technology is required due to the rising demand for clean water. Because of their complementing qualities, photocatalysis and nanofiltration (NF) have become the most promising of these techniques. While nanofiltration efficiently eliminates dissolved salts, heavy metals and micro-contaminants, photocatalysis uses light energy to break down organic pollutants and render microorganisms inactive. The benefits of both systems are combined when photocatalysis and nanofiltration are integrated, allowing for increased pollutant removal, better water quality and longer membrane life. The mechanics underlying photocatalysis and nanofiltration, as well as their respective benefits and drawbacks, are examined in this review. The experimental setup and working of photocatalytic membrane reactor and the integration strategies such as vacuum filtration, phase inversion and interfacial polymerization are presented effectively. Recent advances in these integrated systems such as photocatalytic membranes development and photocatalytic membrane reactor configuration are discussed with a focus on their applications in advanced wastewater treatment or pollutants removal. Challenges including fouling control, energy savings, material reliability and scale-up for practical implementation are examined severely. Lastly, future perspectives stress the necessity of creating multipurpose materials, streamlining process setups and removing technological and financial obstacles.
Waste printed circuit boards (WPCBs) are hazardous solid wastes that are composed of various metal and non-metal materials. Pyrolysis has long been regarded as an environmentally friendly and promising application technology for recovering organic and inorganic materials from the WPCBs. The pyrolysis atmosphere and co-existing materials are critical factors that significantly influence the pyrolysis behavior. To compare the specific effects of these factors on the pyrolysis characteristics of the WPCBs, a series of thermogravimetric and kinetics analyses has been conducted. It was then found that the apparent activation energy was reduced when pyrolyzed in CO2 or co-pyrolyzed with glass fibers, which was supposed to result from the enhanced diffusion and phase boundary reactions. In contrast, an increase in the apparent activation energy was observed at the early stage of the co-pyrolysis with Cu, which was inferred to be associated with the Cu-catalyzed cross-linking effects. Specifically, the formed coke might adsorb pyrolysis products and inhibit the diffusion and reduce the reactive phase boundary. Previous studies have primarily focused on the catalysis of metals in the pyrolysis of WPCBs, while other interactions as well as the kinetic effects of glass fibers and pyrolysis atmospheres have received less discussion. The study presented a comprehensive investigation of the roles played by the pyrolysis atmosphere and co-existing materials in the pyrolysis of the WPCBs. It showed that these factors could alter the reaction-controlling mechanisms by complex interactions. These findings can provide new mechanistic insights and contribute to the use and optimization of pyrolysis-based recycling technologies.
Effective treatment of chlorobenzene (CB)-contaminated waste air is crucial, although biological methods are often constrained by mass transfer limitations and biodegradability. This study presents an innovative two-phase partitioning biotrickling filter coupled with magnetic bioenhancement, employing newly developed non-aqueous phase (silicone oil) immobilized polyurethane foams encapsulated in magnetically modified polyhedral hollow spheres. The removal efficiency of chlorobenzene (CB) improved by 15.6% in compared to the immobilized non-aqueous phase (INAPs) group, and by 37.2% in comparison to the control group at the inlet concentration of 150 mg/m3 with a residence time of 60 s. INAPs enhanced CB mass transfer, with kinetic analysis revealing further improvement induced by the magnetic field (MF). INAPs also promoted the secretion of extracellular polymers (EPS) by 26.8%, with enhanced secretion of loosely/tightly bound EPS promoting resistance to environmental stress. Microbial activity was optimized through INAPs that reduce substrate inhibition, with MF providing further microbial activation. The positively associated effects of INAP and MF on the microbial community was observed to lay the foundation for the positive enhancement of the combination. Overall, this study provides theoretical and technical support for the feasible and efficient treatment of industrial chlorinated volatile organic compounds.
External field-assisted technologies—such as electric fields (EFs), magnetic fields (MFs), and microwave (MW) irradiation—offer promising strategies to overcome the inherent kinetic and thermodynamic limitations of conventional wastewater treatment processes. By modulating charge transport, radical generation, and microbial metabolism, these external fields can substantially enhance the efficiency of both advanced oxidation processes (AOPs) and biological treatment technologies (BTTs). This study systematically explores the underlying mechanisms, operational parameters, and application scenarios of EFs, MFs, and MWs across various treatment systems. Emphasis is placed on the integration of physicochemical and biological perspectives, highlighting how external fields restructure interfacial processes and initiate synergistic pollutant degradation pathways. Representative case studies and optimization strategies are presented to guide field-specific technology selection and energy-efficient system design. Furthermore, critical challenges—including electrode passivation, magnetic catalyst aggregation, and limited MW penetration—are examined, and future directions are proposed to support practical scalability. The insights provided establish a solid foundation for the development of next-generation, high-efficiency, and sustainable wastewater treatment systems enabled by external field enhancement.
Complex anthropogenic activities and geographic conditions in the Chang Jiang(Yangtze R.) Basin have led to significant spatial variations in dissolved heavy metal contents, posing potential threats to aquatic ecosystems. To investigate the ecological risks and drivers of dissolved heavy metals in the Chang Jiang(Yangtze R.) Basin, physicochemical indicators, heavy metals, and nutrient salts were collected and measured, and the ecological risk was evaluated by using a tiered ecological risk assessment and structural equation model (SEM) for driver analysis. The results revealed that the mean values of As, Pb, Cr, Zn, Ni, Cd, and Cu were lower than those of Class III, among which the coefficients of variation of Cd and Pb were greater than 100%, which were affected by human activities. Tiered ecological risk assessment, ranging from deterministic point estimation methods to probabilistic hazard quotient evaluation approaches, demonstrated that Zn poses a potential ecological risk to aquatic organisms and is the key contaminant driving ecological risk in the study area, whereas As, Pb, Cr, Ni, Cd, and Cu do not constitute adverse ecological risk. The results of the SEM revealed that T, elevation, and land use types were the main drivers of spatial variations in the levels of heavy metals, with standardized path coefficients of –0.82, 0.21, and 0.14, respectively. The results of this study can provide theoretical support for ecological risk assessment and driver analysis of dissolved heavy metal pollution, which is of great practical importance for surface water pollution prevention and water environmental protection.
Conventional wastewater treatment facilities lack the appropriate design to abate the presence of antibiotics, which are potential hazards in natural water sources. The use of electroactive bacteria and biochar to eliminate antibiotics has been reported; however, the impact and underlying mechanisms by which biochar enhances the biodegradation of antibiotics by electroactive microorganisms remain unclear. As chloramphenicol exhibits a high degree of toxicity to aquatic organisms, this study investigated the synergistic effect of biochar on the biodegradation of chloramphenicol by electroactive Shewanella oneidensis MR-1. Biochar significantly improved chloramphenicol degradation rates from 36.05% to 70.79% within 24 h by promoting electron transfer processes in S. oneidensis MR-1, a typical electroactive microorganism. This study offers unique insights into the electrochemical properties of biochar, particularly those influenced by pyrolysis temperature, in enhancing the microbial electron transfer processes. Furthermore, the findings demonstrated that biochar not only promotes the growth and activity of electroactive bacteria but also facilitates direct and indirect electron transfer mechanisms, leading to significantly improved antibiotic degradation rates. In summary, biochar is a novel perspective in environmental biotechnology that offers an innovative approach to address the challenge of persistent antibiotics in wastewater treatment.
In Fenton-like reaction activated by peroxymonosulfate (PMS), compared to SO4•– produced via the electron acceptance path, 1O2 generated from electron donation path were more attractive. Herein, PMS activation path was altered from SO4•– to 1O2 through improving Lewis acidity on catalytic sites. During ZIF-67 preparation, vanillin (VAN) was introduced to regulate the chemical environment around the Co3+/2+ nodes. The coordinated N atoms in 2-methylimidazole were partially substituted by O atoms in VAN, leading to the enhanced Lewis acidity on Co3+/2+ sites. In this case, Lewis base PMS were likely to donate electrons to electron-deficient Co3+/2+ sites, and 1O2 were generated as the primary radicals. Besides, coordinatively unsaturated metal sites (CUMSs) were produced during the substitution process, since Co3+/2+ nodes were not fully bridged by VAN ligands. This improved the PMS utilization efficiency and 1O2 yield. Previous studies have indicated the metal leaching would be worsened by CUMSs, owing to the lack of ligand protection. To solve this problem, a Co2SiO4 shell was coated on VAN-ZIF-x surface. VAN-ZIF-x@Co2SiO4 yolk@shell nanoreactor not only suppressed the metal leaching, but also improved the environmental adaption. This paper gave a novel insight on altering the PMS activation path, together with the CUMSs creation on catalyst surface.