Jiangyue Zhao, Tunga Salthammer, Alexandra Schieweck, Erik Uhde, Tareq Hussein
{"title":"Long-term prediction of climate change impacts on indoor particle pollution - case study of a residential building in Germany.","authors":"Jiangyue Zhao, Tunga Salthammer, Alexandra Schieweck, Erik Uhde, Tareq Hussein","doi":"10.1039/d4em00663a","DOIUrl":"https://doi.org/10.1039/d4em00663a","url":null,"abstract":"<p><p>Extreme weather phenomena are increasing in nature, which affects indoor air quality and especially particle concentrations in several ways: (1) changes in ambient pollutant concentrations, (2) indoor particle formation from gas-phase reactions, (3) building characteristics, (4) particle dynamic processes, and (5) residential behavior. However, there are only a few studies that have examined future indoor particle concentrations in relation to climate change, even though indoor spaces are intended to protect people from local climate influences and health risks posed by pollutants. Consequently, this work focuses on the expected long- and short-term concentrations of airborne particles in residences. For this purpose, we applied the computer-based Indoor Air Quality Climate Change (IAQCC) model to a residential building as part of a case study. The selected building physics data represent a large part of the German building structure. The long-term prediction is based on the shared socio-economic pathway (SSP) scenarios published by the Intergovernmental Panel on Climate Change (IPCC). When assuming that the activities of residents remain unchanged, our long-term simulations (by 2100) show that the decreasing outdoor particle concentration will compensate for the indoor chemistry driven particle increase, leading to an overall decreasing trend in the indoor particle concentration. Nevertheless, outdoor air pollution events, such as dust storms and ozone episodes, can significantly affect indoor air quality in the short term. It becomes clear that measures are needed to prevent and minimize the effects of outdoor pollutants under extreme weather conditions. This also includes the equipment of buildings with regard to appropriate construction design and smart technologies in order to ensure the protection of human health.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143389541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sex differences in cardiac fibrosis induced by gestational exposure to polystyrene nanoplastics in mice offspring.","authors":"Xin Li, Haotian Cao, Qianqian Yang, Siqi Yu, Lizheng Huang, Qiao Liu, Xinyi Xiao, Siqi Chen, Jialing Ruan, Xinyuan Zhao, Liling Su, Yihu Fang","doi":"10.1039/d4em00642a","DOIUrl":"https://doi.org/10.1039/d4em00642a","url":null,"abstract":"<p><p>The increasing accumulation of plastics in the environment has raised concerns regarding their potential health hazards. Nanoplastics (NPs) can get transported across the placental barrier, resulting in detrimental effects on developing offspring. To date, the effects of maternal exposure to NPs during pregnancy on the cardiac toxicity in adult offspring have not been conclusively evaluated. Herein, the potential for cardiac injury in the progeny of adult mice that were gestationally exposed to 80 nm polystyrene NPs (PS-NPs) at different doses (0, 0.5, 1, and 5 µg µL<sup>-1</sup>) through oropharyngeal aspiration was investigated. Gestational exposure to PS-NPs resulted in cardiac fibrosis and cardiomyocyte apoptosis, and induced an increase in malondialdehyde (MDA) levels in adult offspring hearts, which were sex-specific and dose-dependent. The mRNA expression levels of estrogen receptor (ER)-related genes, such as <i>Esr1</i>, <i>Esr2</i>, and <i>GPER1</i>, were found to be significantly decreased on exposure to low-dose PS-NPs but elevated on exposure to high-dose PS-NPs in offspring hearts. Furthermore, the magnitude of this elevation in male offspring significantly exceeded compared to that of the female offspring. Additionally, the expression levels of <i>Esr2</i> and <i>GPER1</i> in male offspring that were gestationally exposed to high-dose PS-NPs were found to be higher than those observed in female offspring. The observed sex difference in cardiac fibrosis may be correlated with oxidative stress and changes in ER-related gene expression in the offspring's heart. Overall, our study demonstrated that gestational PS-NP exposure induces significant cardiac injury in adult offspring, providing crucial data on the transgenerational effects of PS-NP exposure in mice.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143389542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The effects of formation modes of ferrihydrite-low molecular weight organic matter composites on the adsorption of Cd(II).","authors":"Xin Nie, Erping Bi, Shiyun Qiu","doi":"10.1039/d4em00710g","DOIUrl":"https://doi.org/10.1039/d4em00710g","url":null,"abstract":"<p><p>The interactions between iron oxides and organic matter (OM) play vital roles in the geochemical cycle of cadmium (Cd). However, the effects of the formation modes of ferrihydrite (Fh)-low molecular weight OM (<i>e.g.</i>, fulvic acid (FA)) composites on Cd(II) adsorption remain poorly understood. The immobilization mechanisms of Cd(II) on Fe-OM composites formed by adsorption and coprecipitation at varying C/Fe molar ratios were investigated by means of adsorption batch experiments, two-dimensional correlation spectroscopy, and surface complexation models (SCMs). The composites formed by adsorption or coprecipitation exhibited a crystal structure similar to that of Fh. Ligand exchange and hydrogen bonding were identified as the primary mechanisms between components in adsorption composites and coprecipitates, respectively. Compared to coprecipitates, the adsorption composites showed a higher adsorption capacity and formed ternary complexes (Fh-FA-Cd). In coprecipitates, Cd(II) primarily interacted with the carboxyl and hydroxyl groups of FA and the hydroxyl groups of Fh. With increasing C/Fe molar ratios, the FA functional group (R-COOH) in adsorption composites responded more quickly to Cd(II). However, the order of functional group reactions in coprecipitates was unaffected by C/Fe molar ratios, which is due to the irregular distribution of C and Fe elements. SCM calculation results indicated that Cd(II) distribution on Fh in adsorption composites was higher than that in coprecipitates. The molar ratios of C/Fe and Cd(II) concentrations influenced the distribution of Cd(II) on the composites, with the highest proportion of Cd(II) on Fh reaching about 70%. These findings contribute to understanding Cd behavior in environments with periodically fluctuating redox conditions.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143381126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Camil Rex M, Bikram Poddar, Sanmitra Mandal, Soupam Das, Amitava Mukherjee
{"title":"Interactive toxicity effects of metronidazole, diclofenac, ibuprofen, and differently functionalized nanoplastics on marine algae <i>Chlorella</i> sp.","authors":"Camil Rex M, Bikram Poddar, Sanmitra Mandal, Soupam Das, Amitava Mukherjee","doi":"10.1039/d4em00780h","DOIUrl":"https://doi.org/10.1039/d4em00780h","url":null,"abstract":"<p><p>Pharmaceutical products (PPs) and nanoplastics (NPs) are prominent emerging contaminants that pose serious threats to marine ecosystems. The present study aimed to investigate both pristine and combined toxicity of PPs (metronidazole, diclofenac, and ibuprofen) and polystyrene nanoplastics (PSNPs) with amine (NH<sub>2</sub>-PSNPs) and carboxyl (COOH-PSNPs) surface functionalization on marine microalgae <i>Chlorella variabilis</i>. Toxicity assessment included the evaluation of growth inhibition, total reactive oxygen species production, malondialdehyde content, antioxidant activity, and photosynthetic activity. Furthermore, changes in the surface functional groups of the algae after exposure to contaminants were examined. The correlation among the toxicity endpoints was assessed using Pearson correlation and cluster heatmap analysis. Zeta potential analysis and hydrodynamic size measurements revealed that the PSNPs became unstable in the presence of PPs. This instability facilitated the aggregation and rapid settlement of PSNPs, consequently impeding their direct interaction with algal cells. Growth inhibition results indicated that <i>Chlorella variabilis</i> exhibited minimal growth inhibition when exposed to pristine PPs (1 mg L<sup>-1</sup>), whereas PSNPs (1 mg L<sup>-1</sup>) caused substantial growth inhibition. Notably, the combined toxicity of PSNPs and PPs was lower compared to pristine PSNPs. The independent action model revealed that the combination of PPs and PSNPs showed an antagonistic mode of interaction. The potential reasons for the decreased toxicity observed in the mixture of PSNPs and PPs compared to pristine PSNPs can be attributed to diminished oxidative stress and enhanced photosynthetic activity. These findings provide valuable insights into the role of PPs in modulating the toxicity of PSNPs towards microalgae.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143363324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joshua D Miller, Nicholas J Herkert, Heather M Stapleton, Heileen Hsu-Kim
{"title":"Silicone wristbands for assessing personal chemical exposures: impacts of movement on chemical uptake rates.","authors":"Joshua D Miller, Nicholas J Herkert, Heather M Stapleton, Heileen Hsu-Kim","doi":"10.1039/d4em00440j","DOIUrl":"10.1039/d4em00440j","url":null,"abstract":"<p><p>Silicone wristbands are utilized as personal passive sampling devices for exposure assessments of semi-volatile organic compounds (SVOCs). While research demonstrates that accumulation of SVOCs on the wristbands correlates with internal dose for many different chemical classes, the mechanisms of accumulation remain poorly understood. Multiple factors such as movement of the individual lead to variable mass transfer conditions at the sampler interface. The objective of this study was to investigate the effect of air flow velocity across the wristband surface on SVOC uptake rates and to evaluate if enhanced rates vary between compounds with a range physicochemical properties. Experiments were conducted in a residential home where wristbands were either held in static conditions or attached to an end-over-end rotator at different speeds for a four week period. We measured the uptake of 17 different SVOCs that are commonly detected in indoor environments and compared their accumulation rates as a function of the rotating velocity. For wristbands moving at tangential speeds of 0.05, 0.5, and 1.1 m s<sup>-1</sup> (relevant for a walking pace), the motion enhanced uptake rates by 1.2 ± 0.2, 3.2 ± 0.6, and 4.3 ± 0.8 times the respective rates for the static controls. This enhancement is consistent with gas phase diffusion-controlled mass transfer theory at the wristband interface. Moreover, the enhancement of uptake positively correlated with octanol-air partition coefficients log <i>K</i><sub>OA</sub> (<i>R</i> = 0.6; <i>p</i> < 0.02) of the chemicals and negatively correlated with diffusivity (<i>R</i> = 0.5; <i>p</i> < 0.05). In a comparison with worn wristband studies, the ratio of uptakes rates for worn relative to rotating wristbands correlated with SVOC properties (<i>R</i> = 0.85 for log <i>K</i><sub>OA</sub>). For SVOCs with log <i>K</i><sub>OA</sub> > 9, uptake rates on worn wristbands greatly exceeded (by a factor of 10 to 10<sup>4</sup>) the respective rates in this rotator experiment. These results suggest that a mass transfer mechanism based solely on gas-solid partitioning under variations in air velocity cannot fully explain uptake on worn wristbands. Instead, the results implicate additional processes such as particle phase deposition, direct contact with certain materials, and excretion from skin as pathways of accumulation on the wristband sampler and personal exposure.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11800079/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143254392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Uptake of per- and polyfluorinated alkyl substances by dry farmed oats following the agricultural application of biosolids and compost.","authors":"Gabrielle P Black, Luann Wong, Thomas M Young","doi":"10.1039/d4em00502c","DOIUrl":"https://doi.org/10.1039/d4em00502c","url":null,"abstract":"<p><p>A significant portion of municipal biosolids is land applied, often to support crop production. Although per- and polyfluoroalkyl substances (PFAS) are widely detected in biosolids, their fate in agricultural systems is not yet fully understood, especially at the field-scale. This study evaluated the uptake of 33 PFAS compounds with chain lengths of C3-C18 over one growing season in dry farmed oats grown in soils on two fields with a long history of receiving biosolids amendments. No PFAS compounds were detected in the crops grown in the two biosolids-amended fields, nor in oats grown on three subplots of a nearby USDA Certified Organic field receiving no amendment, compost, and a combination of compost and lime. Nine PFAS compounds were detected in biosolids samples at two sites with ∑<sub>PFAS</sub> equal to 95.4 μg kg<sup>-1</sup> and 8.9 μg kg<sup>-1</sup>, dominated mainly by perfluorooctane sulfonate (PFOS), perfluorohexanoic acid (PFHxA), and perfluorooctanoic acid (PFOA). Soil residuals before application and at the time of harvest were mainly defined by concentrations of PFOS, followed by other perfluoroalkyl acids and were not significantly different before and after the years' growing season. No residues were detected in dry-farmed oats grown on biosolids- or compost-amended fields in this study, suggesting that the likelihood of the PFAS compounds studied here accumulating in similar crops grown under similar conditions is minimal.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143187787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Syed Moosa Ali, Jayanarayanan Kuttippurath, Aswathy Vijaya Krishna, Anurag Gupta, Debojyoti Ganguly, Anjaneyan P, Mini Raman, Arvind Sahay, K N Babu
{"title":"An in-depth analysis of the impact of environmental drivers on the variability of phytoplankton community in the Arabian Sea during 2010-2021.","authors":"Syed Moosa Ali, Jayanarayanan Kuttippurath, Aswathy Vijaya Krishna, Anurag Gupta, Debojyoti Ganguly, Anjaneyan P, Mini Raman, Arvind Sahay, K N Babu","doi":"10.1039/d4em00385c","DOIUrl":"https://doi.org/10.1039/d4em00385c","url":null,"abstract":"<p><p>This study examines the long-term changes in phytoplankton size classes (PSCs) in the Arabian Sea (AS) using the remote sensing reflectance (<i>R</i><sub>rs</sub>) data collected over 12 years (2010-2021) from the Moderate Resolution Imaging Spectroradiometer (MODIS). The <i>R</i><sub>rs</sub> spectra were inverted to chlorophyll-a (Chl-a) concentrations using a non-linear optimisation method, which were then used to estimate the PSC using a region specific three-component model. The analysis is carried out for all four seasons, <i>i.e.</i>, winter (December-February), pre-monsoon (March-May), monsoon (June-September) and post-monsoon (October-November). A machine learning random forest (RF) model is employed to predict the seasonal and long-term variability in PSCs and to quantify the influence of environmental drivers. The seasonal climatology of three size classes - micro (larger), nano (medium-sized), and pico (smaller) - reveals that micro-phytoplankton predominantly occupy the northern AS during winter and pre-monsoon seasons, contributing over 50% to the total Chl-a. During the monsoon season, a significant rise in micro-phytoplankton contribution (60-80%) is noted off the coasts of Somalia, Oman and Kerala due to strong upwelling. In contrast, nano-phytoplankton contributions are minimal during the pre-monsoon season but remain fairly consistent in other seasons, and pico-phytoplankton dominates the oligotrophic waters of the central and southern AS during pre- and post-monsoon. The analysis of PSCs from 2010 to 2021 shows a strong decreasing trend in micro-phytoplankton concentration (-0.13 ± 0.19 mg m<sup>-3</sup> year<sup>-1</sup>), accompanied by a steady increase in pico-phytoplankton (0.0009 ± 0.0005 mg m<sup>-3</sup> year<sup>-1</sup>) and nano-phytoplankton (0.001 ± 0.0009 mg m<sup>-3</sup> year<sup>-1</sup>). To elucidate these long-term trends, RF model was instrumental in identifying key environmental drivers, with sea surface temperature (SST) emerging as the most influential factor affecting pico- and micro-phytoplankton. The feature importance scores for SST are highest during winter and pre-monsoon for both pico-phytoplankton and micro-phytoplankton, underscoring the sensitivity of these classes to temperature changes. RF model also highlights the role of mixed layer depth (MLD) and wind speed (WS) in driving the seasonal shifts in PSCs, particularly during the monsoon and post-monsoon periods. These findings suggest that the rise in SST, coupled with changes in vertical mixing and stratification, drives the shift towards smaller cells, mainly pico-phytoplankton in the AS. This shift towards smaller cells indicates a possible decline in marine food chain efficiency, reduced carbon export rates and declining primary productivity-a real concern for food security in the region.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143187869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Photodegradation of typical psychotropic drugs in the aquatic environment: a critical review.","authors":"Chuanguang Wang, Ruonan Guo, Changsheng Guo, Hailong Yin, Jian Xu","doi":"10.1039/d4em00669k","DOIUrl":"https://doi.org/10.1039/d4em00669k","url":null,"abstract":"<p><p>Continuous consumption combined with incomplete removal during wastewater treatment means residues of psychotropic drugs (PDs), including antidepressants, antipsychotics, antiepileptics and illicit drugs, are continuously entering the aquatic environment, where they have the potential to affect non-target organisms. Photochemical transformation is an important aspect to consider when evaluating the environmental persistence of PDs, particularly for those present in sunlit surface waters. This review summarizes the latest research on the photodegradation of typical PDs under environmentally relevant conditions. According to the analysis results, four classes of PDs discussed in this paper are influenced by direct and indirect photolysis. Indirect photodegradation has been more extensively studied for antidepressants and antiepileptics compared to antipsychotics and illicit drugs. Particularly, the photosensitization process of dissolved organic materials (DOM) in natural waters has received significant research attention due to its ubiquity and specificity. The direct photolysis pathway plays a less significant role, but it is still relevant for most PDs discussed in this paper. The photodegradation rates and pathways of PDs are influenced by various water constituents and parameters such as DOM, nitrate and pH value. The contradictory results reported in some studies can be attributed to differences in experimental conditions. Based on this analysis of the existing literature, the review also identifies several key aspects that warrant further research on PD photodegradation. These results and recommendations contribute to a better understanding of the environmental role of water matrixes and provide important new insights into the photochemical fate of PDs in aquatic environments.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lucy J Webster, Ryan Ballard, Tom Beamish, Tim Burnhope, Jack Humbert, Alastair C Lewis, Jakub Piaszyk, Sarah J Moller
{"title":"Evaluating low NO<sub><i>x</i></sub> hydrogen engines designed for off-road and construction applications.","authors":"Lucy J Webster, Ryan Ballard, Tom Beamish, Tim Burnhope, Jack Humbert, Alastair C Lewis, Jakub Piaszyk, Sarah J Moller","doi":"10.1039/d4em00448e","DOIUrl":"https://doi.org/10.1039/d4em00448e","url":null,"abstract":"<p><p>Hydrogen internal combustion engines offer a near-term decarbonisation pathway for hard to electrify sectors such as non-road mobile machinery (NRMM). However, few hydrogen-specific engines have ever been developed with the twin-goals of maximising low carbon energy efficiency and delivering air quality co-benefits. We present analyses of dynamometer-derived nitrogen oxides (NO<sub><i>x</i></sub>) tailpipe emissions from four variants of a ∼55 kW four-cylinder port fuelled injection spark ignition hydrogen internal combustion engine (H2ICE) suitable for a range of uses within the NRMM industry. Engine out (pre-aftertreatment) emissions are also reported for one of the H2ICE variants. The emissions were compared over the Non-Road Transient Cycle (NRTC) with an equivalent contemporary Stage V emissions compliant 55 kW diesel engine. All four H2ICE variants were configured to operate under lean burn conditions generating substantially lower NO<sub><i>x</i></sub> exhaust emissions over the NRTC when compared to the diesel engine. Lowest NO<sub><i>x</i></sub> emissions were observed for a spark ignition H2ICE with selective catalytic reduction and particulate filter (SCRF) aftertreatment. Tailpipe NO<sub><i>x</i></sub> emissions over the full NRTC for this configuration were 1.90 mg kWh<sup>-1</sup>, a greater than 99% reduction compared to diesel (3340 mg kWh<sup>-1</sup>) with lower average NO<sub><i>x</i></sub> emissions observed for the H2ICEs over all power, torque, and speed settings. The frequency and magnitude of transient (<20 ms) increases in NO<sub><i>x</i></sub> were also compared between diesel and H2ICE. A H2ICE using a hydrogen slip catalyst, but without SCRF aftertreatment, also emitted significantly lower tailpipe NO<sub><i>x</i></sub> than the diesel equivalent (63.7 mg kWh<sup>-1</sup>), a factor of greater than 50 times improvement over the NRTC. This creates a systems level dilemma: whether the additional small absolute reductions in NO<sub><i>x</i></sub> achieved using SCRF would have a net benefit that outweighed the broader financial and environmental costs of the SCR and exhaust fluid manufacture, distribution and possible small in-service ammonia slip from exhaust. Irrespective of aftertreatment system, the adoption of low NO<sub><i>x</i></sub> emitting H2ICE in NRMM, and particularly construction equipment, would appear to offer much greater near-term air quality benefits for cities when compared to switching to other low carbon alternatives such as biodiesel or hydrotreated vegetable oil.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H K M Mihiranga, Yan Jiang, M G S Sathsarani, Xuyong Li
{"title":"Dissolved phosphorous through dry-wet-dry transitions in a small-dammed river basin: integrated understanding on transport patterns, export controls, and fate.","authors":"H K M Mihiranga, Yan Jiang, M G S Sathsarani, Xuyong Li","doi":"10.1039/d4em00686k","DOIUrl":"https://doi.org/10.1039/d4em00686k","url":null,"abstract":"<p><p>An integrated understanding of dissolved phosphorous (DP) export mechanism and controls on export over dry and wet periods is crucial for riverine ecological restorations in dammed river basins considering its high bioavailability and retention rates at dams. Riverine DP transport patterns (composition, sources, and transport pathways), export controls, and fate were investigated over the 2020 wet season (5 events) and dry seasons before and after it (2 events: dry<sub>(before)</sub> and dry<sub>(after)</sub>) in a semi-arid, small-dammed watershed to comprehend the links between terrestrial DP sources and aquatic DP sinks. Close spatiotemporal monitoring of the full range of phosphorous and total suspended solids (TSSs) and subsequent analyses (hysteresis, hierarchical partitioning, and coefficient of variation) provided the basis for the study. Total-DP (TDP) shared 13-39% (25%) of total-P (TP) through storms, dissolved organic-P (DOP) shared 6-21% (12%), and phosphate-P shared (PO<sub>4</sub>-P) 7-22% (13%). DP forms displayed strong connections with discharge trends across the wet season, and marked changes in the shares were reported over dry-wet and wet-dry transitions. The DOP fraction of TDP increased from 4% in dry<sub>(before)</sub> baseflow to 64% at the end of the wet season. The DOP flux increment in stormflow was 20 folds compared to dry<sub>(before)</sub> baseflow, while that of PO<sub>4</sub>-P was 2 folds. DOP displayed the least spatial source heterogeneity with minimum anthropogenic pressure on inherent fluxes. DOP originated from overland and near-stream soil sources and was transported <i>via</i> surface runoff and soil water runoff, respectively. Across the wet season, the attrition of overland DOP sources and activation of near-stream soil DOP sources through strengthened hydrological connectivity governed the seasonal DOP trends. Surface and groundwater runoff pathways were important for PO<sub>4</sub>-P delivery during stormflow; nonetheless, wastewater treatment plant (WWTP) effluent was the main PO<sub>4</sub>-P source under both baseflow and stormflow regimes, followed by near-stream traditional agriculture lands. The interaction patterns of small dam systems with DP inputs through dry-wet periods were explained. The riverine PO<sub>4</sub>-P fluxes were profoundly impacted by in-stream biogeochemical and physical processes and small dam systems, while riverine DOP fluxes were relatively less influenced.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}