Current Pollution Reports最新文献

Purpose of Review

This review summarizes the current knowledge (definition, source, formation, structure, chemical composition, and health effects) about atmospheric soot particles and aims to analyze their health effects combined with their structural characteristics.

Recent Findings

The new understanding of soot microstructure (analogous to reduced graphene oxide (RGO)) suggests the presence of oxygen-containing functional groups (OFGs) in carbonaceous core (CC) of soot, which may enhance its health effects. Toxicological studies have proved that the two major components (CC and outer coating) both contribute to soot toxicity, but there is still controversy over who is playing the main role. Recently, there are many studies questioning the past experimental results. The bioavailability of the outer coating bound on CC is particularly pointed out to be taken into account for soot toxicity. Existing epidemiological studies on black carbon (BC), a near-synonym of soot in atmospheric science, have prompted the adverse health effects especially for cardiovascular system. A stronger association between short term BC exposure and health endpoints is lately found than fine particulate matter (PM_2.5), but still needs more consistent evidence. Therefore, the health effects of soot need more attention as well as comprehensive and in-depth research.

Summary

It is evident from the review that soot is a responsible agent for adverse health effects, which may exceed PM_2.5. The CC and outer coating have been proved to exert toxicity separately, of which oxidative stress, inflammation, and DNA damage are most important toxicity mechanisms. However, their antagonistic interaction may weaken the toxicity of the whole soot particle.

Purpose of Review

This review aims to provide a comprehensive examination of oxidation flow reactor (OFR) studies and their applications in both laboratory and field investigations. OFRs play a crucial role in understanding secondary organic aerosol (SOA) formation and aging processes in the atmosphere. By evaluating the advancements and limitations of OFR technology, this review seeks to identify key research directions and challenges for future studies in atmospheric chemistry and air quality research.

Recent Findings

In recent years, OFR has emerged as an encouraging alternative to smog chambers for SOA study. The high oxidative capacity and short residence time of OFR enable its wide application in both laboratory and field studies. Research utilizing OFR has uncovered the critical role of semi-volatile and intermediate-volatility organic compounds (S/IVOCs) in the formation of SOA from various sources, including vehicle emissions, biomass burning, cooking activities, and non-traditional emissions such as volatile chemical products. Notably, field studies have observed considerable variability in the SOA formation potential across different environments globally, generally showing higher formation potential in urban areas compared to rural and forest regions.

Summary

OFR studies have significantly advanced our understanding of SOA formation and aging processes, identifying key precursors, evaluating influencing factors, and quantifying SOA formation potential. However, challenges remain in unraveling detailed mechanisms due to the complexity of SOA sources and properties. Future OFR research should focus on innovations in OFR design, study non-traditional emissions, conduct long-term field observations, develop standardized calibration procedures, and establish SOA yield parameterization schemes for S/IVOCs.

Purpose of Review

Different drying methods can cause errors in determining the content and evaluating the biological effectiveness of various forms of phosphorus (P) in sediment. The drying pretreatment effectively promotes the conversion of amorphous iron and aluminium oxides to their crystalline form, which ultimately impacts the adsorption capabilities of sediment. However, limited research has been conducted in this field previously. Sediments from the Weiyuan River, Baoenqiao Reservoir, and Honghu Lake in China were pretreated using freeze-drying, air-drying, and oven-drying methods. The effects of pretreatment methods on P were evaluated through P fractionation and isothermal adsorption experiments. The study also investigated the proportion and amount of amorphous iron and aluminium (Fe_ox and Al_ox) transformed into crystalline forms.

Recent Findings

The results revealed that drying pretreatment markedly increased the potentially bioavailable P(BAP) (6.73%). This increase can be attributed to the rise in loosely-bound P (48.30%) and P bound to metal oxides (9.51%), which are predominant contributors to BAP. Furthermore, sediment adsorption performance significantly decreases after drying pretreatment. This is due to the reduced content of Fe_ox (64.02%) and Al_ox (36.61%), which exhibit higher P adsorption capacity. Additionally, drying led to a significant reduction in SP_max (25.09%) and PSI (28.20%), along with an increase in EPC₀ (24.96%) and DPS (6.83%).

Summary

Different drying treatments affected the P forms and sorption properties of the sediment to varying degrees, with the overall effect being oven-drying > air-drying > freeze-drying > fresh samples. Consequently, when fresh sediment is not available for laboratory analysis, freeze-drying may be a more realistic method for characterizing P properties.

Graphical Abstract

Purpose of Review

The response to COVID-19 in the global community resulted in a disruption of usual sensory experiences associated with quotidian life and special events. While research has investigated urban and rural soundscape alteration/change during COVID and post-COVID, no summative work has focused on soundscapes of traditional (heritage) festivals. Research is warranted as cultural heritage festivals are significant and fundamental for human societal functioning, and associated soundscapes are a key aural reflection of these. This paper aims to critically review literature published from 2020 on the effect of COVID-19 on heritage festival soundscapes, with a particular focus on the loss of aural experience examined from a community perspective.

Recent Findings

We identified fourteen articles which covered heritage festival sounds or soundscapes, with the resultant aural experience being transformed, postponed or discontinued due to pandemic restrictions. There was a distinct lack of formal research investigating how communities perceived these changed soundscapes, with perceptions generally based on researcher’s own perspectives, either through informal conversations with community members or through content analysis. Furthermore, we identified no research which specifically targeted community perceptions of transformed heritage festival soundscapes.

Summary

In recognising and understanding both the importance of sensory components in creating a festival atmosphere and the significance of heritage festivals to the community as a cultural signature, the COVID-19 pandemic gives us a chance to pause and consider festival sensory components as an experienced intangible form of heritage and to question how alteration of these sensory heritage experiences concerns the communities affected.

Graphical Abstract

Visual collage of the effect of the COVID-19 pandemic on heritage festival soundscapes

The response to COVID-19 resulted in a disruption of usual sensory experiences. In recognising the importance of festival sensory components in creating an atmosphere and the significance of heritage festivals to the community, the pandemic gives us an opportunity to consider festival sensory components as an experienced intangible form of heritage.

Purpose of Review

The synergistic effects of microplastics (MPs) and heavy metals are becoming major threats to aquatic life and human well-being. Therefore, understanding synergistic interactions between MPs and heavy metals is crucial to comprehend their environmental impacts.

Recent Findings

The mechanisms such as electrostatic attraction, surface interactions, ion exchange, hydrogen bonding, hydrophobic forces, and π–π interactions behind the synergistic effects of MPs and heavy metals were critically reviewed and justified. In addition, the roles of surface chemistry in these interactions were also emphasized. Finally, efficient remediation techniques aligning with a circular economy-based initiative to promote sustainable solutions were recommended to mitigate plastic-heavy metal pollution to achieve a cleaner environment.

Summary

This review examines the combined impact of MPs and heavy metals in aquatic ecosystems, detailing their mechanistic interactions, and consequences with proposed sustainable solutions. Additionally, this review highlights the MP-heavy metal contamination risks and emphasizes the need for further research to safeguard aquatic life and human health.

The presence of nonsteroidal anti-inflammatory drugs (NSAIDs) in various environments poses a significant challenge due to their widespread volume, complexity, and harmful effects on environment and human health. NSAIDs elimination from the ecosystem has become an urgent priority. Therefore, the present study focuses on evaluating specific microorganisms capable of effectively remediating pharmaceutical wastewater and reducing NSAIDs contamination. Acidophile microorganisms exhibit unique survival abilities in acidic conditions and demonstrate the potential for degrading pharmaceutical compounds in wastewater. These microorganisms utilize these compounds as their sole carbon and energy sources, converting them into valuable bioproducts. Acidophile microorganisms display various functional processes, including biodegradation, biotransformation, biosorption, and bioaccumulation. It is noteworthy that bioaccumulation is mostly found in microalgae since they have more protein to uptake NSAIDs. A detailed understanding of bioaccumulation in acidophile microorganisms is recommended as degradation mechanisms. In addition, metabolites can be acknowledged by omics approaches since it has yet to be exposed.

Purpose of Review

As short-chain chlorinated paraffins (SCCPs) have been classified as persistent organic pollutants (POPs), there has been a significant surge in the utilization of medium- and long-chain chlorinated paraffins (MCCPs and LCCPs) as potential alternatives. However, their environmental and ecological risks have gained more prominence. Consequently, the objective of this review is to provide a comprehensive overview of the biological effects, migration, and transformation of chlorinated paraffins (CPs), with a particular focus on comparing the similarities and differences among SCCPs, MCCPs, and LCCPs.

Recent Findings

According to the latest research findings, it has been discovered that MCCPs and LCCPs possess persistence, bioaccumulation, and long-distance migration abilities, similar to SCCPs. Moreover, these research results demonstrate that the toxicity of MCCPs and LCCPs, especially those components with high chlorine content, is equally significant as that of SCCPs. Furthermore, MCCPs and LCCPs in the environment can undergo biotransformation and photodegradation processes, resulting in the generation of toxic substances such as very short-chain chlorinated paraffins (vSCCPs), SCCPs, and chlorinated alcohols.

Summary

This review comprehensively examines the biological toxicity, health risks, migration, and transformation of CPs with different chain lengths. In addition, the study analyzes the sources and trends of vSCCPs, SCCPs, MCCPs, and LCCPs in different environment media. It should be noted that SCCPs pose a greater health risk to aquatic organisms, whereas MCCPs are particularly concerning for infants. On the other hand, LCCPs present a higher health risk to terrestrial organisms, especially those situated at the top of the food chain. Based on the drawbacks of current research, outlook for future research was proposed. This review is expected to provide a reference for more scientific and reasonable evaluation of the CPs environment risk.

Purpose of Review

Lignocellulosic biomass, as a green and sustainable resource, can be used in biorefineries to produce bio-based products. The complex and resistant structure of lignocellulose prevents microorganisms access to carbohydrates in the biorefinery’s main processes, necessitating pretreatment. Different conventional pretreatment methods (physical, physico-chemical, chemical, and biological methods) and also novel advanced oxidation processes (AOPs) and their sustainability, environmental impact, economic viability, energy efficiency and, commercialization state are investigated in this review.

Recent Findings

Due to various reviews and studies on conventional pretreatment methods, they are briefly described with proper data. As the mechanisms and principle of operation of AOPs were investigated, during the AOPs pretreatment methods, hydroxyl radicals (·OH) are generated sufficiently to decompose lignocellulosic structure through oxidation. In this paper, we review the different AOPs, i.e., Fenton process, ozonation, photochemical, wet air oxidation, ultrasound, and electrochemical, which are recently used in the pretreatment of lignocellulose. Also, the achievement of different AOPs pretreatment research studies and general trends governing the process operating conditions are presented briefly in tables. Moreover, lignocellulosic biomass pretreatment sustainability assessment approaches such as life cycle assessment (LCA) and economic value and environmental impact (EVEI) are discussed. Although no study compared the sustainability aspects of different AOPs with conventional methods, this review generally addresses them. Further, environmental, energetic, and economic aspects of AOPs methods have been compared as important criteria in selecting a pretreatment method.

Summary

This review provides a thorough insight into the biorefinery’s bottleneck, pretreatment, and comprehensively investigated mechanisms, principle of operation, sustainability, environmental, economic, energy, and commercialization state of AOPs methods.