Pollutant Compounds Research Articles

Assessment of Long-Term Surface Water Quality in Mekong River Estuaries Using A Comprehensive Water Pollution Index

Surface water quality (SWQ) has been degraded in the Mekong River Basin under increasing pressures of population growth, economic development, and global climate change. This study employed the comprehensive water pollution index (CWPI) to assess the spatio-temporal variation of SWQ in the downstream Mekong River estuaries. Eight water quality parameters were measured between 2005 and 2021 at 21 sampling sites downstream of the Mekong River. These parameters included total suspended solids (TSS), biological oxygen demand (BOD5), chemical oxygen demand (COD), ammonia (N-NH4+), nitrate (N-NO3-), phosphate (P-PO43-), iron (Fe), and total coliform. Most of the monitoring locations in the estuaries of Ham Luong, Cua Dai, Ba Lai, and Co Chien exhibited slightly to moderately polluted conditions, as indicated by the CWPI values ranging from 0.67-2.91, 0.41-2.20, 0.27-3.02, and 0.37-2.95, respectively. TSS and Fe concentrations consistently exceeded the allowable limits, while the majority of values for N-NH4+, N-NO3-, P-PO43-, and coliform remained within acceptable thresholds. Additionally, parameters indicative of organic pollution, namely BOD5 and COD, displayed a noticeable upward trend between 2005 and 2021. SWQ exhibited significant spatial and temporal variations with TSS, organic matter, nutrients, and iron being the main areas of concern. These findings can provide guidance to policymakers involved in the assessment and enhancement of water quality in the presence of pollutant compounds that lead to a decline in water quality.

Interplay of compound pollutants with microplastics transported in saturated porous media: Effect of co-existing graphene oxide and tetracycline

Co-existence of microplastics, nanomaterials, and antibiotics may lead to intensified multifaceted pollution, which may influence their fate in soils. This study investigated the co-transport behavior of polystyrene microplastics (PS) and compound pollutants of graphene oxide (GO) and tetracycline (TC). Packed column experiments for microplastic with or without combined pollutants were performed in KCl (10 and 30 mM) and CaCl2 solutions (0.3 and 1 mM). The results showed transport of PS was facilitated at low ionic strengths and inhibited at high ionic strengths by GO with or without TC under examined conditions. Carrier effect of GO as well as the aggregation of PS in the presence of co-exiting GO or GO-TC could be the contributor. Although the existence of TC relieved the ripening phenomenon of PS and GO deposition due to enhanced electronegativity of sand media, the effect of GO on the PS transport has not been significantly impacted, indicating the dominant role of GO during cotransport process. Furthermore, the transport of PS was increased by TC owing to competition for deposition sites on sand surfaces. In turn, the transport of TC was mainly affected by PS whether graphene was present or not. The increase in electrostatic repulsive force (transport-promoting) and addition adsorption sites (transport-inhibiting) may be responsible for the observations. Our findings could improve understandings of complex environmental behaviors of microplastics and provide insight into investigation on cotransport of emerging contaminants under various conditions relevant to the subsurface environment.

Characteristics Analysis of Volatile Organic Compounds Pollution in Residential Buildings in Northeast China Based on Field Measurement

A total of 8 mechanically ventilated residential buildings and 8 naturally ventilated residential buildings were selected to analyze the pollution characteristics of indoor VOCs under different ventilation modes in the severe cold area of northeast China. On typical meteorological days in each season, VOCs were detected on site, and ventilation modes were investigated by long-term online monitoring. The test results showed that the TVOC (total volatile organic compounds) concentrations varied greatly in different seasons or different functional rooms, and the TVOC concentration was the highest in winter, with a value of 0.994 mg/m3. The kitchen was the place with the most serious VOC pollution, and the TVOC concentration could reach 1.403 mg/m3. Benzene series and methylsiloxane had the highest detection rates, but the detected concentrations were low, and the average concentrations were 0.025 mg/m3 and 0.013 mg/m3 respectively. Among the VOC types with a detection rate greater than 50%, the average proportions of aldehydes, alkanes, and benzene series were 18.7%, 15.39%, and 14.38%, respectively. And their mass ratios were also high, which were 14.90%, 30.85%, and 15.70%, respectively. The annual daily average ventilation duration of mechanically ventilated residential buildings was 7.84 h longer than that of naturally ventilated residential buildings. The median TVOC concentrations of mechanically ventilated residential buildings and naturally ventilated residential buildings were 0.621 mg/m3 and 0.707 mg/m3, respectively. The fresh air system was applicable in the severe cold area of northeast China.

Effects of VOC emissions from chemical industrial parks on regional O3-PM2.5 compound pollution in the Yangtze River Delta

Ozone (O3) and fine particulate matter (PM2.5) compound pollution has emerged as a primary form of air pollution in Chinese urban. Volatile organic compounds (VOCs), as common precursors of O3 and PM2.5, play a significant role in air pollution control. Chemical industrial parks (CIPs) are crucial emission sources of VOCs and have garnered significant attention. This study focused on 142 CIPs located in the Yangtze River Delta (YRD) to investigate the characteristics of VOC emissions from CIPs and their impact on O3-PM2.5 compound pollution, considering the enhanced atmospheric oxidation capacity (AOC). The Comprehensive Air Quality Model with Extensions (CAMx) model was employed for this analysis. The results show that VOC emissions from CIPs contributed significantly to regional O3 and secondary organic aerosol (SOA), accounting for 17.1 % and 18.18 % of the anthropogenic sources, respectively. Regions exhibiting the highest contributions were located along the Hangzhou Bay. Compared with 2014, an elevation in the contribution of VOC emissions from CIPs to the annual average concentrations of MDA8 O3 and SOA in the YRD in 2017 by 0.069 μg/m3 and 0.007 μg/m3, respectively. During episodes of compound pollution, the concentration of atmospheric oxidant (HOx + NO3) was 28.65 % higher than during clean days, and significant positive correlations were observed between hydrogen oxygen radicals (HOx) and maximum daily 8-h average (MDA8 O3) as well as between HOx and SOA, exhibiting correlation coefficients of 0.86 and 0.48, respectively. Effective control measures for VOC emissions, particularly from the pharmaceutical and petrochemical industry parks located along Hangzhou Bay, are essential in curtailing the production rate of HOx and in regulating AOC levels in the YRD. Maintaining the daily average HOx concentration below 10 ppt would be a valuable strategy in achieving coordinated control of O3 and SOA, thus aiding in the alleviation of O3-PM2.5 compound pollution in the YRD.

Research on compound pollution characteristics and health risk evaluation of particulate matter and heavy metals in waste glass recycling process

Owing to the large amount of waste glass generated, the waste glass recycling base is an indispensable municipal supporting facility of a sustainable city. However, waste glass recycling is a complex process involving stages such as multiple-stage crushing and material sorting. Consequently, waste glass recycling base has a considerable impact on the surrounding environment, such as health risk of particulate matter on workers. In this study, we aimed to perform a comprehensive investigation and analysis of compound pollution characteristics and health risk evaluation of particulate matter and heavy metals generated from waste glass recycling process. Soil, particulate fallout, and glass samples were collected from inside and outside a recycling plant in eastern China. Our findings showed that the waste glass treatment process produces a large amount of air particulate matter, and the PM2.5 and PM10 concentrations can reach 3725 and 4055 μg/m3, respectively, in the production workshop during working hours. Meanwhile, the monitoring results show that the concentration of heavy metals on fine particles is higher compared to coarse particles. The high Zn and Pb concentrations detected in the soil and dustfall were proved to be derived from the glass raw materials. However, health risk assessment and particle deposition modeling in the human respiratory system revealed that heavy metals from the air particulate matter have no significant carcinogenicity or non-carcinogenic risk. The Gaussian dispersion model showed that the impact of particulate matter on the surrounding environment and health of the surrounding residents is minimal. Furthermore, transportation is the major emission link according to the particulate emission calculation, indicating that it is imperative to upgrade and reform the existing processes of waste glass recycling. Taken together, this study provides a scientific basis for the green development of waste glass recycling process and further environmental information regarding waste glass recycling plants.

Optimising PtFe nanoparticle structure to enhance catalytic activity and stability for propane oxidation

Although the development of highly active and stable platinum catalysts for the complete oxidation of hydrocarbons is crucial, there are still significant challenges that need to be addressed. Herein, the surface structure of PtFe nanoparticles (NPs) on PtFe/CeO2-x (x = CO, H, O) catalysts was precisely tuned via thermal treatment in CO, H2 and O2 atmospheres. The structure of the PtFe NPs on the PtFe/CeO2-O catalyst consisted of dispersed FeOx nanoclusters anchored on the PtFe NPs core. As a result, the PtFe/CeO2-O exhibited superior activity and water resistance for propane oxidation among all catalysts, which stems from the cooperation among robust metallic Pt sites, abundant active oxygen species, and FeOx nanoclusters as additional sites for oxygen supply. However, the reaction path of propane oxidation was similar among the PtFe/CeO2-x catalysts. This study offers encouraging insights for the deliberate development of robust and high-performing bimetallic catalysts to eradicate volatile organic compound pollutants. SynopsisThe CeO2‑supported core-shell-like PtFe-FeOx NPs catalyst synthesised via calcination treatment in oxygen atmosphere exhibits the excellent activity, good durability and water resistance for propane oxidation at low temperature.

Competitive removal of compound pollution via nano-magnetic Enteromorpha prolifera hydrogel: The binding ability of Cr(VI) is stronger than methyl orange

The contamination of water with heavy metals and dyes has caused severe environmental issues on a global scale, which is further worsened by the interaction of organic and inorganic pollutions. Correspondingly, controlling water contamination by heavy metals and dyes is crucial. Enteromorpha prolifera is improper management results in severe environmental issues. Enteromorpha prolifera was cross-linked to create a hydrogel in this study. Subsequently, a nano-magnetic Enteromorpha prolifera hydrogel fabricated through by the hydrolytic co-precipitation of ferrous ions and its base. It was then used to remove methyl orange (MO) and hexavalent chromium [Cr(VI)] from water. Additionally, the adsorption of MO reached equilibrium in ∼ 30 min with a maximum adsorption capacity of 261.3 mg/g, whereas Cr(VI) adsorption reached equilibrium in just 15 min with a maximum adsorption capacity of 54.2 mg/g. Moreover, MM-EP-HD demonstrated outstanding recovery (magnetic recovery for the fifth time was ≥ 83%). Subsequently, the effects of initial concentration, dosage, contact time, pH, and temperature on the adsorption of MO and Cr(VI) were investigated. Moreover, during the competitive adsorption of MO and Cr(VI) composite pollutants, the hydrogel's adsorption capacity for pollutants in the composite system was higher and faster for Cr(VI) than for MO. A high concentration of Cr(VI) will have a great impact on MO removal, the maximum effect can reduce 73% removal rate, on the contrary, Cr(VI) removal effect is only 25%. The findings demonstrate that MO was adsorbed via hydrogen bonding, ion exchange, and electrostatic interaction, whereas Cr(VI) was adsorbed via electrostatic attraction, ion exchange, and multi-component chelation of surface acid functional groups. The nano-magnetic Enteromorpha prolifera hydrogel has the advantages of high adsorption capacity, good thermal stability, and recyclability. As a functional material with simple preparation and excellent performance, it has good application potential and research value.

Biodegradation of formaldehyde gas pollutant by a novel immobilized haloalkaliphilic Salipaludibacillus agaradhaerens strain NRC-R isolated from hypersaline soda lakes

Indoor formaldehyde (HCHO) exceeding the recommended level, is harmful to human health. The goal of this study was to test the performance of a novel haloalkaliphilic (HAP) Salipaludibacillus agaradhaerens strain NRC-R isolated from hypersaline soda lakes and immobilized in alginate-PVA-chitosan gel composite to biodegrade HCHO gas in a stream of air containing various inlet HCHO concentrations (0.7 ppm and 7 ppm) in laboratory scale. The surface images of the immobilized cells/beads were examined by scanning electron microscopy (SEM). The maximum efficiency of HCHO removal was almost 90% with an inlet loading concentration of 0.7 ppm. Stepwise 10 times augment in the HCHO inlet concentration (7 ppm) showed that the immobilized strain was able to control this very high concentration and removed about 60% over 72 h of the treatment. Although several studies have been reported on the isolation of HAP bacteria from various environments, but to our knowledge, this is the first report on the isolation and immobilization of highly HCHO-controlled HAP bacterial strain from soda lakes of hypersaline in Egypt. This bio-system has a high biodegradation capacity via HCHO gas pollutant even with the higher concentrations (7 ppm). It is assumed that HAP S. agaradhaerens NRC-R strain could be utilized in the remediation and biodegradation of HCHO air pollutants. Furthermore, this novel strategy may be considered in employing such bacteria as a biotechnological treatment technique that reduces the environmental pollution rate and might be useful to control other organic compound pollutants in many industrial fields.

Two halogenated flame retardants and cadmium in the soil-rice system: sorption, root uptake, and translocation.

The migration and transformation of Tetrabromobisphenol A (TBBPA), DechloranePlus (DP), and cadmium in soil-rice system was investigated, and the influence on the quality of two varieties of rice was studied. The degradation half-lives of TBBPA, BBPAs, syn-DP, and anti-DP were 23.18 ~ 26.36days, 30.14 ~ 36.10days, 72.96-81.55days, and 169.06-198.04days in the soil. TBBPA was gradually degraded to tri-BBPA, di-BBPA, mono-BBPA, and bisphenol A by the debromination. TBBPA and its bromide metabolites could be bioaccumulated in different tissues of rice; mono-BBPA and bisphenol A was easy to accumulate in the stems, and bisphenol A was easy to bioaccumulate in the grain. Comparing with single and compound pollution, there was no significant difference in bioaccumulation factors of two rice species. The grain of NO7 had stronger bioaccumulation ability to mono-BBPA and BPA than NO1, and there is no significant difference in TBBPA. Residual level of DP in the rice: roots > stems > grain; there was no significant difference in bioaccumulation of two varieties of rice. Cadmium was easily bioaccumulated in the roots of rice and translocated to the rice stems and grains. NO7 rice had stronger bioaccumulation and transport capacity than NO1. The effects of the three pollutants on the quality of two varieties of rice varied significantly; cadmium had the greatest effect on the iodine blue value (BV) and amylase activity of the grain. This study proved that selecting rice varieties with low bioaccumulation to polluters can effectively reduce the risk of the food chain harming human health.

Interactions between phenanthrene and polystyrene micro/nano plastics: Implications for rice (Oryza sativa L.) toxicity

Micro/nano plastics (MPs/NPs) are widely distributed and are one of the global pollutants of current concern. Micro/nano plastics can adsorb a variety of persistent organic pollutants, and different particle sizes and surface charges affect the biological effects of MPs/NPs. Therefore, how the compound pollution of MPs/NPs with different particle sizes and organic pollutants produces toxic effects on plants needs to be further studied. We investigated the toxic effects of phenanthrene (Phe) and amino-modified PS (PS–NH2) with two particle sizes (50 nm, 5 μm) on rice. The stress mechanism of PS-NH2 was different between the two particle sizes. Moreover, 50 nm PS-NH2 inhibited stomatal conductance and transpiration rate, reduced photosynthetic rate, significantly enriched GO functions such as “DNA repair” and “DNA double-strand break,” and caused severe DNA damage in rice. Notably, 5 μm PS-NH2 affected the gene expression of “photosynthetic lighting” and “photosynthetic antenna protein” in rice, decreased chlorophyll content, and inhibited rice growth. The toxicity of 50 nm PS-NH2 was stronger. In addition, we found that Phe reduced the toxicity of PS-NH2 with different particle sizes, and the relief effect of 50 nm PS-NH2+Phe was more evident. Further, 50 nm PS-NH2+Phe alleviated the toxicity by stimulating the activities of antioxidant enzymes, reducing oxidative damage to chloroplasts, and inhibiting photosynthesis. However, 5 μm PS-NH2+Phe can reduce the stress by reducing the degree of membrane lipid peroxidation, activating metabolic pathways related to the cell wall and cell membrane formation, and plant antitoxin biosynthesis. The results contribute to the understanding of the mechanism of toxicity of MPs/NPs and polycyclic aromatic hydrocarbons (PAHs) to crops.

Preparation of LSPR enhanced Z-scheme Pd/WO3@SnO2 for photocatalytic decomposition of organic compounds under simulated sunlight

The decoration of semiconductor photocatalysts with metal nanoparticles (NPs) is an efficient strategy for improving their performance via localized-surface-plasma-resonance (LSPR). For this study, a LSPR enhanced Z-scheme Pd/WO3@SnO2 photocatalyst was synthesized, which revealed excellent photocatalytic performance and reusability against Rhodamine B (RhB) with degradation rate of 100 % after 1 h under simulated sunlight. The reaction rate constants (k) of the Pd/WO3@SnO2 were ∼4.9, 3.5, and 2.1 times higher than those of the WO3, SnO2, and WO3@SnO2, respectively. In this Z-scheme-structure, the transfer efficacy of photogenerated electrons was significantly promoted due to integrated electric-field between the SnO2 and WO3, which was supported by experimental results and theoretical calculations. The deposited Pd nanoparticles served as an electron-transfer-bridge, as well as a LSPR excitation source, which played significant role in the degradation of RhB. The photodecomposition pathway of RhB was explored, and the toxicities of the intermediates were evaluated. Moreover, tetracycline (TC), chlortetracycline-hydrochloride (CTC), doxycycline-hydrate (DOX), and oxytetracycline (OTC) were tested as common antibiotic models to verify the effectiveness of the catalysts. The degradation efficiencies for TC, CTC, DOX, and OTC over Pd/WO3@SnO2 attained 90.98 %, 96.33 %, 75.37 %, and 50.90 %, respectively, under simulated sunlight, which confirmed its strong potential for the removal of recent pollutants. Experiments and electron paramagnetic resonance (EPR) tests indicated that •O2– served as the major active species in the photocatalysis process, while •OH and h+ played secondary roles. Finally, an LSPR enhanced direct Z-scheme mechanism was proposed. This study provides a rational design strategy for the development of more efficient Z-scheme photocatalysts that exploit the LSPR-effect for photodecomposition of organic pollutant compounds.

Construction of ACNF/Polypyrrole/MIL-100-Fe composites with exceptional removal performance for ceftriaxone and indomethacin inspired by “Ecological Infiltration System”

Developing advanced adsorbents for removing the alarming level of pharmaceuticals active compounds (PhACs) pollution is an urgent task for environmental treatment. Herein, a novel acid-treated carbon nanofiber/polypyrrole/MIL-100-Fe (ACNF/PPy/MIL-100-Fe) with stable 3D-supporting skeleton and hierarchical porous structure had been fabricated to erasure ceftriaxone (CEF) and indomethacin (IDM) from aqueous solution. ACNF as scaffold achieved the highly uniform growth of MIL-100-Fe and PPy. Viewing the large BET surface area (SBET, 999.7 m2/g), highly exposed accessible active sites and copious functional groups, ACNF/PPy/MIL-100-Fe separately showed an excellent adsorption capacity for CEF (294.7 mg/g) and IDM (751.8 mg/g), outstripping the most previously reported adsorbents. Moreover, ACNF/PPy/MIL-100-Fe reached rapid adsorption kinetics and standout reusability property. Further, the redesigned easy-to-recyclable ACF/PPy/MIL-100-Fe inspired by the electrode formation craft achieved prominent adsorption capacity and good reusability property. The adsorption mechanism was evaluated via Fourier transformed infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The outcomes revealed that the splendid adsorption capability mainly depended on the electrostatic interactions, hydrogen bonding and π-π interactions. This work sheds light on one facile practical strategy to exploit advanced materials in water environmental remediation.

Impacts of aerosol direct effects on PM2.5 and O3 respond to the reductions of different primary emissions in Beijing-Tianjin-Hebei and surrounding area

In recent years, the rapid pollution emission reductions significantly decreased the PM2.5, which weakened the aerosol radiation feedback effect and in turn influenced the changes of PM2.5 and O3. To promote our understanding of this effect, we used an online-coupled meteorology-chemistry model (WRF-Chem) to investigate the influence of aerosol direct effects (ADE) on PM2.5 and O3 responding to different pollutant emissions reduction for a summer PM2.5-O3 compound pollution month in Beijing-Tian-Hebei region (BTH) and surrounding area. We performed scenario simulations with turning on/off both aerosol influences on the meteorology (ADE_MET) and photolysis (ADE_PHO), and turning on only ADE_PHO with different reduction ratios for primary PM2.5 (100%), SO2 (80%) and NOx (40%) emissions. Our results showed that total reduction of primary PM2.5, SO2 and NOx emissions led to overall declines of surface PM2.5 in BTH and surrounding area. The SO2 and NOx emission reductions both furtherly decreased PM2.5 via the changed ADE, while the primary PM2.5 emission reduction increased the PM2.5 by its induced ADE. Different from PM2.5, O3 significantly increased in BTH after cutting the three types of emissions. The primary PM2.5 emission reduction led to O3 increase over the whole region mostly by the induced ADE, while the NOx emission reduction directly enhanced O3 in the plain areas mainly due to incompatible reduction of NOx and VOCs emissions. The O3 enhanced by emission-reduction-induced ADE accounted for 56.1% of the total increase. The ADE_PHO caused by PM2.5 primary emissions reduction was the dominant contribution to the total ADE induced increases of PM2.5 and O3, which enhanced the photolysis of gases and led to overall increase of oxidants that strengthened secondary aerosol formation, and also promoted the production of O3 via photochemical processes. The results implicate that with the continuously strengthened abatement of PM2.5 primary emissions, it may offset part of the reduction effect on PM2.5 decrease by the changed ADE, and also increase O3 over the whole region. The results also suggested that while controlling both PM2.5 and O3 in BTH in summer, not only the cooperative emission reduction of NOx and VOCs is essential, the induced ADE effect by PM2.5 primary emissions reduction should also be considered.

Biological Evaluation and Key Stress Factor Diagnosis of Compound Contaminated Soil Based on Environmental DNA

Healthy biological community composition and diversity are the basis for soil ecosystems to provide complete ecological functions and services. The current technical bottleneck in soil pollution control is the lack of systematic and comprehensive biodiversity indicators. In this study, the compound-polluted soil in an industrial park was taken as the object, and environmental DNA (eDNA)technology was used to monitor and analyze the composition of the biological community in the polluted soil. The environmental DNA-species sensitivity distribution (eDNA-SSD) method was constructed to diagnose the key stress factors and their ecological threshold. The results showed that:① compound pollution did not have a significant impact on the α-diversity of soil organisms in the park but led to changes in the composition of biological communities and dominant species with high relative abundance. The dominant groups in the polluted soil were Proteobacteria (25.54%), Ascomycota (15.65%), Actinobacteria (8.75%), and Chloroflexi (7.64%). ② Environmental factors accounted for 51.27% of the differences in soil biodistribution, and aniline, sulfate, petroleum hydrocarbon, and lead were the key stress factors for soil biomes. Among them, aniline had the most significant effect on the community distribution of bacteria (P=0.030), sulfate on fungi (P=0.025), and metazoans (P=0.032). ③ The ecological risk threshold (hazardous concentration for 5% of species, HC5) of pollutants with 95% species as the protection target showed a gradient decreasing trend of sulfate (470.00 mg·kg-1), petroleum hydrocarbon (17.00 mg·kg-1), lead (13.00 mg·kg-1), arsenic (6.20 mg·kg-1), 4-chloroaniline (0.16 mg·kg-1), and aniline (0.11 mg·kg-1). Nevertheless, the existing soil risk control value was significantly higher than the ecological risk value, indicating that the existing control standards targeting human health were not suitable for protecting soil health. The comprehensive pollution index showed that the soil pollution in the park was mostly mild pollution accompanied by heavy pollution at individual points. The biological evaluation method based on eDNA-SSD could achieve the comprehensive evaluation of composite pollution in the absence of the benchmark value of pollutants and at the same time better distinguish the differences in soil biological community structure and composition under different pollution levels (P=0.053). In conclusion, the environmental DNA soil biomonitoring and assessment method developed in this study has guiding significance and application value for soil ecosystem restoration assessment.

Contribution of marine biological emissions to gaseous methylamines in the atmosphere: An emission inventory based on multi-source data sets

Methylamines are a class of highly reactive organic alkaline gases in the atmosphere. At present, the gridded emission inventories of amines used in the atmospheric numerical model is mostly based on the amine/ammonia ratio method and do not consider the air-sea exchange of methylamines, which oversimplifies the emission scenario. Marine biological emissions (MBE), an important source of methylamines, has been insufficiently investigated. These shortcomings in the inventories can limit the simulation of amines by numerical models in the context of compound pollution in China. To acquire a more complete gridded inventory of amines (monomethylamine (MMA), dimethylamines (DMA), and trimethylamines (TMA)), we established a more reasonable MBE inventory of amines by using multi-source data sets (Sea Surface Temperature (SST), Chlorophyll-a (Chla), Sea Surface Salinity (SSS), NH3 column concentration (NH3), and Wind Speed (WS)), and merged it with the anthropogenic emissions (AE) inventory (by adopting the amine/ammonia ratio method and the Multi-resolution Emission Inventory for China (MEIC)). The new methodology can reveal the air-sea exchange fluxes and direction of different amines. Oceans can act as a sink for DMA and source for TMA while it can be either a source or sink for MMA. The concentration of amines above the coastal area increased significantly when the MBE was merged to the AE inventory. TMA and MMA showed significant increases, TMA increased by 43,917.0 %, and 804.0 %, in July 2015 and December 2019, respectively; while MMA increased by 2635.4 % and 0.37 % during the same periods; however, only slight changes were observed in the DMA concentration (−3.9 % in July 2015, and 1.1 % in December 2019). WS, Chla, and the total dissolved concentration of amines ([C+(s)tot]) were found to be the dominant factors affecting MBE fluxes. In addition, the emission fluxes and spatial distribution of AE, and wet deposition also affect the simulation of amines concentration.

Identifying pollution dynamics using discrete Fourier transform: From an urban-rural river, Central Mexico

The quality of life and human survival is dependent on sustainable development and sanitation of water bodies in an environment. The present research focuses on cyclicity data of more than 750,000 records of parameters associated with the water quality from a rural-urban river monitoring stations in real-time from River Atoyac in Central Mexico. The events detected in the instrumental records correlated with 2528 laboratory and instrumental determinations. The 64 polluting compounds were grouped into inorganic compounds (metals and metalloids) and organic compounds (pesticides, herbicides, hydrocarbons). Metal associated compounds were grouped along mechanical, pharmaceutical and textile industries which associates itself with the entry of polluting components. The cyclicity of the events was detected through Discrete Fourier Transformation time series analysis identifying the predominant events in each station. These highlight the events at 23–26 h corresponding to a circadian pattern of the metabolism of the city. Likewise, pollution signals were detected at 3.3, 5.5, and 12–14 h, associated with discharges from economic activities. Multivariate statistical techniques were used to identify the circadian extremes of a regionalized cycle of polluting compounds in each of the stations.The results of this research allow pollution prevention using a mathematical analysis of time series of different quality parameters collected at monitoring stations in real-time as a tool for predicting polluting events. The DFT analysis makes it possible to prevent polluting events in different bodies of water, allowing to support the development of public policies based on the supervision and control of pollution.

Spatiotemporally anthropogenic PM2.5- and O3-related health economic losses via weather normalization technique and hierarchical policies in Chinese cities

IntroductionWith the promulgation of air pollution control policies, there are still many cities where the PM2.5 concentration exceeds 35 μg/m3, and O3 pollution is increasingly apparent.MethodsThe spatio-temporal evolution and differentiation characteristics of PM2.5 and O3 pollution were explored, and then compound pollution hotspot urban agglomerations were screened out. A weather normalization technique was used to identify the driving amount, the influence of meteorological factors, and the anthropogenic emissions quantitatively, on pollution in hotspot urban agglomeration. Furthermore, the health and economic losses due to PM2.5 and O3 in hot cities in 2015–2020 were quantified. Finally, a natural break-point classification method was used to establish the health loss rating systems for PM2.5 and O3.Results and DiscussionThe results showed the following: (1) From 2015 to 2020, 78%, 72%, 69%, 58%, 50%, and 41% of the annual mean PM2.5 concentration had exceeded 35 μg/m3, respectively, and 17%, 18%, 31%, 33%, 30%, and 17% of the annual mean O3 concentration exceeded 160 μg/m3, respectively, in 337 cities in China. (2) From 2015 to 2020, the health losses caused by PM2.5 and O3 were ranked as follows: Beijing–Tianjin–Hebei (BTH; 1968, 482 people) > Shandong Peninsula (SDP; 1,396, 480 people) > Central Plains (CP; 1,302, 314 people) > Yangtze River Delta (YRD; 987, 306 people) > Triangle of Central China (TC; 932, 275 people) > Guanzhong Plain (GZP; 869, 189 people). (3) The average economic losses associated with public health of the PM2.5 and O3 were ranked as follows: BTH (2.321 billion, 3.218 billion RMB, 1 RMB = 0.0.1474 USD on 20 January 2023) > SDP (1.607, 2.962 billion RMB) > YRD (1.075, 1.902 billion RMB) > TC (1.016 billion, 1.495 billion RMB) > CP (1.095, 1.453 billion RMB) > GZP (0.69, 0.828 billion RMB). Therefore, combining hot pollution factors, the regional characteristics of the priority control areas, and the national 14th 5-Year Plan, targeted control countermeasures were proposed.

Degradation of hexavalent chromium and naphthalene by electron beam irradiation: Degradation efficiency, mechanisms, and degradation pathway

Heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) in industrial wastewater have attracted much attention due to their damage to the environment and the human body. Studies have shown that there may be interactions between PAHs and HMs, leading to enhanced toxicity of both pollutants. It has been shown that traditional methods are difficult to treat a combination of PAHs and HMs simultaneously. This paper presented an innovative method for treating PAHs and HMs compound pollutants by electron beam irradiation and achieved the removal of the compound pollutants using a single means. Experiments showed that the absorbed dose at 15 kGy could achieve 100% degradation of NAP and 90% reduction of Cr (Ⅵ). This article investigated the effects of electron beam removal of PAHs and HMs complex contaminants in various water environmental matrices. The experimental results showed that the degradation of NAP followed the pseudo-first-order dynamics, and the degradation of NAP was more favorable under neutral conditions. Inorganic ions and water quality had little effect on NAP degradation. For electron beam reduction of Cr (Ⅵ), alkaline conditions were more conducive to reducing Cr (Ⅵ). Especially, adding K2S2O8 or HCOOH achieved 99% reduction of Cr (Ⅵ). Experiments showed that •OH achieve the degradation of NAP, and eaq− achieve the reduction of Cr (Ⅵ). The results showed that the degradation of NAP was mainly achieved by benzene ring opening, carboxylation and aldehyde, which proved that the degradation of NAP was mainly caused by •OH attack. The toxicity analysis results showed that the electron beam could significantly reduce the toxicity of NAP, and the toxicity of the final product was much lower than NAP, realizing the harmless treatment of NAP. The experimental results showed that electron beam irradiation has faster degradation rates and higher degradation efficiency for NAP and Cr (Ⅵ) compared to other reported treatment methods.

Imaging VOC distribution and tracing emission sources in surface water by a mobile shipborne spray inlet proton transfer reaction mass spectrometry

Volatile organic compound (VOC) pollution in surface water can affect the growth of microorganisms and even cause damage to human health. Quickly obtaining VOC distribution and tracing emission sources are of great significance to ensure the security of water quality. In this study, we developed a mobile shipborne spray inlet proton transfer reaction mass spectrometry (S-SI-PTR-MS) instrument for rapid and on-line detection of volatile organic compounds (VOCs) in surface water. It mainly consists of a shipborne platform, a spray inlet system, a proton transfer reaction mass spectrometer, and geographic information software (GIS). During the navigation, VOCs in water can be quickly extracted to gaseous state by the SI system and transferred into the proton transfer reaction mass spectrometry (PTR-MS) for detection. The GIS can receive VOC and longitude-latitude data at the same time. And then the identification and concentration information can be shown on an electronic map in real time. The limit of detection and response time were 1.32 μg/L∼9.43 μg/L and 56 s∼114 s, respectively. The spatial resolution is 0.14 m in a common navigation experiment (5 km/h, dwell time=0.1 s), allowing for high-resolution monitoring of VOCs in water. Finally, field experiments were performed on the lower Nanfeihe River and some surfaces of Chaohu Lake in China. During tracing pollution in Nanfeihe River, two VOC emission sources in the downstream were located, nearing a sewage outlet and a wharf, respectively. During imaging VOC distribution in the Chaohu Lake, we found the areas with high-concentration VOCs were mainly along the ship channel. The newly developed S-SI-PTR-MS can monitor water quality in surface water in real time and has the potential to assist environmental protection enforcement.

Summertime carbonyl compounds in an urban area in the North China Plain: Identification of sources, key precursors and their contribution to O3 formation

Carbonyl compounds are critical components of volatile organic compounds, which significantly participate in the photochemical formation of atmospheric ozone and thus threaten human health. Here we measured 15 C1–C8 carbonyl compounds at an urban site in Linyi, a typically industrialised city in the North China Plain (NCP). Formaldehyde (3.89 ppbv), acetaldehyde (1.66 ppbv) and acetone (2.03 ppbv) were found to be the top three carbonyl compounds, accounting for 76.11% of the total concentration of carbonyl compounds. Anthropogenic secondary formation was recognised as the main source of the top five carbonyl compounds, which included formaldehyde, acetaldehyde, acetone, butyraldehyde and benzaldehyde, and accounted for 46–54% of all sources. Alkenes were the most important precursors of formaldehyde and acetaldehyde, suggesting that reducing the emission of alkenes from anthropogenic sources is an effective way to control carbonyl compound pollution in Linyi. Furthermore, the photolysis of carbonyl compounds played a significant role (68–75%) as sources of HO2• and RO2• and thus made a significant contribution (14.6%) to the photochemical formation of O3. This study highlights the importance of anthropogenic secondary formation as a source of carbonyl compounds and provides a scientific basis for O3 pollution control in carbonyl compound-enriched cities in the NCP.