Current Pollution Reports最新文献

Purpose of Review

Second-generation (2G) bioethanol produced from lignocellulosic biomass is green liquid transportation fuel. Manufacture and use of 2G bioethanol involves several stages. Hence, the impact of 2G bioethanol on all segments of ecosystem needs to be assessed. Life Cycle Assessment (LCA) accounts for the complete environmental impact of 2G bioethanol using several factors. This review has presented an overview and analysis of recent literature on LCA of 2G bioethanol.

Recent Findings

Recent LCA studies reveal reduction in GHG emissions with bioethanol-blended gasoline. The net energy ratio of bioethanol is > 1. However, bioethanol's acidification and eutrophication potential is high due to chemicals used during crop cultivation and biomass pretreatment. LCA studies also suggest use of lignin for electricity co-generation for closed carbon cycle.

Summary

LCA analysis reveals that use of renewable resources during bioethanol manufacture (solar/wind electricity and biofertilizers) can enhance the sustainability of 2G ethanol.

Purpose of Review

Biogenic volatile organic compounds (BVOCs) are essential for ecosystem functioning and climate. In natural environments, plants are exposed to a complex mixture of pollutants and environmental stressors, and combined exposure to these factors can produce effects that differ significantly from those of individual influences. However, comprehensive reviews on BVOC emission resulting from exposure to air pollution and its interactions with environmental variables remain limited.

Recent Findings

Rapid industrialization has exacerbated air pollution, characterized by increased levels of ozone (O₃) and carbon dioxide (CO₂) in the atmosphere, along with extreme climatic events such as heat waves and droughts. These stresses induced by air pollution and environmental factors may trigger plant defense mechanisms, leading to adjustments in metabolism and respiration or may damage plant cells, ultimately affecting the composition and intensity of BVOC emissions.

Summary

This review highlights that O₃ generally stimulates BVOC emissions, with a relatively smaller effect on isoprene but notable sensitivity in sesquiterpenes. In contrast, elevated CO₂ levels can suppress emissions across the three BVOC types investigated. Warming significantly boosts emissions, while drought has little effect on isoprene but substantially enhances sesquiterpene emissions. These analyses are limited by substantial uncertainties due to data scarcity. Additionally, the combined effects of air pollutants and environmental variables vary by plant species, VOC types, and stressor intensities. This review also summarizes current methodologies for investigating BVOC emissions, explores plant-pollutant-stressor interactions, identifies research gaps, and offers insights for advancing the understanding of stress-induced BVOC emissions in a changing environment and climate. 

Graphical Abstract

Purpose of Review

Despite significant improvements in particulate pollution, ozone (O₃) levels have unexpectedly worsened in Shandong Province, China (SDP), which is one of the world’s hotspots for O₃ pollution. This review aims to summarize O₃ pollution studies in SDP and highlight the challenges faced by current research efforts.

Recent Findings

The interaction between O₃ chemistry and meteorological conditions has exacerbated O₃ pollution in SDP, with frequent increases in nighttime O₃ levels. Both local emissions and regional transport play significant roles in O₃ pollution, with O₃ production being particularly sensitive to VOCs in most cities. The worsening O₃ pollution has led to increased health risks and ecological damage.

Summary

This review provides a comprehensive overview of O₃ pollution in SDP, covering formation mechanisms, in-situ measurements, source analyses, and the health and ecological impacts. It is recommended that monitoring networks be scientifically optimized, urgent mitigation strategies for VOCs and NOx be implemented, and collaborative research efforts be intensified to address O₃ pollution at regional scales.

Purpose of Review

Hydrochar derived from biomass is a promising sustainable adsorbent for pollutants, though its efficiency is often constrained by limited pore size and active sites. Physical activation can be effectively utilized to enhance physical structure and modify surface. This environmentally friendly process is well-suited for large-scale applications in pollution mitigation.

Recent Findings

Gaseous and mechanical activation methods are emerging as highly effective strategies for enhancing hydrochar materials. Gaseous activation techniques can significantly enlarge surface area, develop porosity, modify surface chemistry, and control structural characteristics. In contrast, mechanical activation methods are adept at reducing particle size, increasing surface exposure, and diversifying functional groups.

Summary

This paper explores how different physical activation processes impact the functional properties of hydrochar. It delves into the mechanisms behind changes in physicochemical characteristics, offering new insights for developing advanced hydrochar materials to align with emerging technologies.

Synthesis gas (syngas) fermentation represents a promising biological method for converting industrial waste gases, particularly carbon monoxide (CO) and carbon dioxide (CO₂) from industrial sources (e.g. steel production or municipal waste gasification), into high-value products such as biofuels, chemicals, and animal feed using acetogenic bacteria. This review identifies and addresses key challenges that hinder the large-scale adoption of this technology, including limitations in gas mass transfer, an incomplete understanding of microbial metabolic pathways, and suboptimal bioprocess conditions. Our findings emphasize the critical role of microbial strain selection and bioprocess optimization to enhance productivity and scalability, with a focus on utilizing diverse microbial consortia and efficient reactor systems. By examining recent advancements in microbial conditioning, operational parameters, and reactor design, this study provides actionable insights to improve syngas fermentation efficiency, suggesting pathways towards overcoming current technical barriers for its broader industrial application beyond the production of bulk chemicals.

Purpose of Review

The exponentially increasing plastic pollution in environment requires effective and sustainable biodegradation methods. Superworm (larvae of Zophobas atratus also known as Zophobas morio) have been shown to ingest and degrade plastics/microplastics depending on environmental conditions. Because there is no sufficient knowledge of the effect of plastics/microplastics on superworms and analysis of their degradation mechanism, it is timely to provide more evidences to demonstrate their capability, impact, degradation pathways, and remaining challenges. Therefore, this review aims to comprehensively discuss the ability of superworms to degrade plastics or microplastics (MPs).

Recent Findings

Superworms have demonstrated the ability to metabolize various types of plastics or MPs into carbon dioxide and larval biomass. The degradation process involves depolymerization and subsequent microbial action within their gut, leading to a reduction in the size and chemical complexity of the plastics. Microbes such as Pseudomonas sp., Enterobacteriaceae sp., and Enterococcus sp. have been commonly observed in the gut of superworms.

Summary

This review showed that most previous works focus on the use of superworms to degrade/remove PS, whereas other types of plastic polymers, such as polyethylene terephthalate (PET), have not been explored. Implementation of this technology has the potential to significantly reduce plastic pollution and support environmental sustainability solutions.

Purpose of Review

Nanotechnology has transformed various aspects of contemporary life, technology, and research. This is evident in the rising global demand for and use of nanoparticles, leading to a corresponding increase in their discharge into the environment through diverse human activities. In the last few years, the rampant use of copper oxide nanoparticles (CuO-NPs) has piqued interest.

Recent Findings

CuO-NPs are widespread and tend to remain in the environment, enabling them to increase in concentration through the food chain and ultimately impact human health. When aquatic organisms are exposed to CuO-NPs, it may cause oxidative stress. This can change proteins, cause lipid peroxidation, and damage DNA. This can ultimately cause cytotoxicity, genotoxicity, and epigenetic changes.

Summary

CuO-NPs produce reactive oxygen species (ROS), which can have various consequences for organisms and the environment. The objective of the review was to introduce a refreshed audit on the ecotoxicity, a comparison of systems related to CuO-NPs, and an assessment of the safe limit to prevent chronic toxicity across different taxa: aquatic invertebrates, plants, and algae. Additionally, the article briefly discusses the existing knowledge gaps in this area and makes recommendations for future research.

Purpose of Review

Electrochemical advanced oxidation processes have emerged as a promising technology to efficiently remove recalcitrant organic pollutants. Electro-Fenton (EF) processes are highlighted due to fast reaction kinetics, facile operating parameters, and low energy consumption. Nanomaterials with competitive surface area and catalytic activity, such as metal–organic frameworks (MOF), are being explored as catalysts to make the EF treatment process more effective. This paper reviews the recent trends in implementing iron-based MOFs in electrochemical Fenton-based technologies while highlighting needed improvements to further bolster their potential for industrial application.

Recent Findings

The majority of early research to design iron-based MOF catalysts has utilized MOF pyrolysis to design catalysts that outperform traditional iron catalysts in terms of stability and degradation efficiency. Research focus has now shifted to designing stable pure MOF catalyst material instead of MOF-derived catalysts for EF treatment, often by complementing iron with the addition of a second metal. Designing pure iron–based MOF catalysts that can be employed directly in suspension instead of embedded upon a cathode can simplify catalyst synthesis and application, bolstering their potential for industrial use. These new methods have demonstrated efficacy in both acidic and basic pH operating conditions while extending the life cycles of catalysts to achieve high removal of trace pharmaceuticals and organic dyes. Despite this, factors such as complicated synthesis and limited understanding around catalyst stability in realistic water conditions still present concern for further research improvement.

Summary

This study explores how iron-based MOFs have been used to enhance as a competitive catalyst for both electro-Fenton and heterogeneous photoelectro-Fenton (HPEF) processes for water/wastewater treatment, but other engineering considerations such as reusability and operating conditions must be improved to advance this emerging process towards higher technology readiness levels. Through this study, current research is critiqued to provide a research roadmap towards successful MOF catalyst implementation.

Purpose of Review

Antibiotics are widely distributed in aquatic environment and pose a potential risk to ecosystems at trace levels. Constructed wetlands (CWs) have been considered a sustainable and low-cost solution for pollutant removal. Therefore, the theme of antibiotic removal in constructed wetlands has become very important.

Recent Findings

Many studies have reviewed the removal performance of antibiotics in different CWs. The properties of antibiotics (such as pKa, LogKow, and toxicity) are reported, which are not linked with their removal performance in different CWs. The dominant pathways for antibiotic removal in different CW configurations remain unknown. Removal of conventional pollutant and antibiotic in CWs are independently studied. The impacts of antibiotic involvement on conventional pollutant removal and changes in microbial communities in CWs need further investigation.

Summary

This review summarized the removal performance of commonly used antibiotics in different types of CWs and identified the specific types of antibiotics (i.e., β-lactams, macrolides, and sulfonamides) that are relatively difficult to remove. It systematically illustrated the mechanisms of essential CW components and their interactions on antibiotic removal. It also discussed the correlation between antibiotic properties and their removal efficiencies, indicating the dominant removal pathways in three CW types. Furtherly, this review analyzed the key operational factor regulation and CW structure modifications on antibiotic removal. Additionally, it concluded that antibiotics generally inhibited the removal of some traditional pollutants (excluding NH₄⁺-N) based on the data from current reports.

Graphical Abstract

Agriculture systems worldwide rely on synthetic fertilizers to meet the food production demand of the burgeoning population. Over the decades, the abundant use of these synthetic chemicals has posed a significant threat to the environment and declined crop nutrient uptake efficiency (NUE). Nanocarriers can modulate nutrient release kinetics and extend their availability in the rhizosphere and phyllosphere, improving NUE and crop nutrition. Our review provides insights into the role of nano-fertilizers (NFs) in promoting sustainable agriculture, various macro- and micronutrient fertilizers and formulations and green synthesis methods. An extensive and systematic literature review was conducted, and the data under various sections has been identified using a computerized bibliographic search via the Web of Science, Scopus, Google Scholar and CAB abstracts, as well as several websites. Over the past decade, considerable research has been conducted employing the NFs for crop nutrition, development, doses and formulations, improving NUE, impacting crop stress resilience, improving economic viability and environmental sustainability and promoting safety. Use of NFs over conventional fertilizers has yielded a positive and significant impact, encompassing all crop production scenarios. NFs provided sustained nourishment to crops throughout the development phases, from germination to harvest, while minimizing the runoff and leachate losses and improving soil properties. Several advancements in the NFs production utilizing green synthesis methods involving microbes and plant materials are developed to reduce pollution, environmental hazards and global warming. Conventional fertilizers possess major constraints like dynamic chemical forms, which are more challenging for plants to absorb and do not provide sustained release of nutrients. NFs are the best alternatives to increase nutrient uptake, crop yield and soil productivity. However, the synthesis approaches involve high-energy and aggressive chemical reagents. The green synthesis of NFs remains the sustainable, eco-friendly, economically viable, reliable and energy-efficient approach which uses microbial and plant extracts. However, the future potential of NFs in promoting sustainability relies on toxicology research that reveals their limitations, offering a thorough understanding of safe crop nutrition with NFs.