Organic Compounds Pollution Research Articles

Phase-Engineered ZrO2 for Tuning Catalytic Oxidation of Dichloromethane Over W/ZrO2:Zr-Doped WOx Clusters and the Hydrolysis-Oxidation Mechanism.

Catalytic elimination through an oxidative decomposition pathway is the most promising candidate for the purification of chlorinated volatile organic compound (CVOC) pollutants, but the complicated mechanisms and the formation pathways of hydrogenated byproducts still need to be clearly revealed. Herein, W/ZrO2, as a structure-tunable catalyst, is used to catalytically oxidize dichloromethane (DCM) and clarify the formation pathway of monochloromethane (MCM). Crystal engineering of ZrO2 tailors surface WOx species; practically, the predominant Zr-WOx clusters and crystalline WO3 can be obtained on monoclinic (m-ZrO2) and tetragonal (t-ZrO2) phases. Surface Zr-WOx species are highly active due to their distorted structure and abundant Lewis acid sites. In situ DRIFTS reveal that H2O accelerates the cycle between W═O and O═W─Cl as well as replenishes consumed hydroxyls, improving the durability of W/m-ZrO2, and thus a hydrolysis-oxidation mechanism is proposed. Moreover, a hydride transfer pathway for MCM formation as a hydrodechlorinated byproduct is identified. -OCH2O- as the direct hydride donor is generated by the dissociation of DCM on surface active oxygen species or hydroxyls, and then transferred to C+H2Cl species on Lewis acid sites to produce MCM. This work could potentially contribute to developing novel oxidative elimination strategies for CVOCs and the rational design of efficient catalysts.

Biomechanics identification and risk management strategy of volatile organic compound pollution sources integrated with machine learning algorithms

Microplastic pollution has emerged as a critical environmental issue, posing significant threats to aquatic ecosystems and human health. As an innovative approach, biological techniques have shown great potential in mitigating microplastic contamination in water systems. This study explores the use of biotechnological methods, such as microbial degradation and biofilm-assisted filtration, in combination with conventional water treatment processes to enhance the removal of microplastics. Focusing on Southwest China, where water pollution is exacerbated by rapid urbanization and industrial activities, the research identifies the ecological and technical challenges unique to this region. Experimental approaches include optimizing bio-coagulation using microbial consortia, assessing enzymatic degradation of common microplastic polymers, and evaluating the biomechanical interactions between biological agents and microplastic particles during water filtration. Results aim to provide insights into the efficacy and scalability of integrating biological solutions into existing water treatment frameworks. This study contributes to developing sustainable and eco-friendly strategies for addressing microplastic pollution and safeguarding water quality through biologically informed interventions.

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Factors affecting distribution and ecological risk assessment of volatile organic compounds (VOCs) in groundwater of the Huazhou district in northwestern China

Volatile organic compounds (VOCs) pollution in groundwater is a significant global concern. In this study, 26 groundwater samples were collected from the unconfined aquifers in Huazhou District, northwestern China, to assess their distribution characteristics, influencing factors, and ecological risks across various geomorphological settings. The findings revealed 35 VOCs in collected groundwater samples, with aromatic hydrocarbons having the highest detection rate (100%), and the VOCs distribution exhibited significant spatial variations, with the highest VOCs concentration near a chemical plant on the inclined pluvial plain. The lithology and groundwater flow influenced the vertical and lateral transport of VOCs, with concentrations decreasing as the aquifer permeability decreases along the groundwater flow from the inclined pluvial plain to the river. The Mantel test was used to analyze the correlation between VOCs and environmental factors, geochemical analyses indicated that nitrate (NO3-) and sulfate (SO42-) served as electron acceptors in the anaerobic biodegradation of organic pollutants, with bicarbonate (HCO3-) levels increasing as a result of this biodegradation. Additionally, the curved streamline searchlight shaped model (CS-SLM) was applied to identify the primary land use types affecting VOCs content, construction land and cropland were primary land use types affecting VOCs distribution. Finally, the ecological risk assessment indicated the highest risk quotient (RQ) for styrene (0.21), suggesting a manageable risk level. The study emphasizes the complexity of VOCs contamination in groundwater, providing a foundation for targeted mitigation strategies.

Healthy air for healthy minds

Abstract Background The adverse health effects from exposure to air pollution is increasingly known. A recent report shows that at least 95% of the world’s population breathe air containing dangerous levels of pollutants. According to estimates from the World Health Organization (WHO), ambient air pollution is related to 4.2 million deaths every year. Less is known about the association between indoor air (especially particulate matter 2.5 and volatile organic compounds (VOC) pollution and mental health conditions. Many sources of indoor air pollution exist, such as pressed wood products, pesticides, secondhand smoke, stoves, heaters, overcrowding and fireplaces. Aims We aim to synthesize knowledge on the effects of particulate matter 2.5 in indoor air and mental health conditions. Methods We systematically reviewed the association of indoor air pollution with mental health conditions using the databases Pubmed and EMBASE. Results Exposure to indoor air pollutants is associated with increased anxiety and depression and less cognitive performance. These results are robust; however, the impact of PM2.5 is larger for less-educated and female respondents. Females cook with solid fuels and biomass more often. Physical exposure and gender factors overlap in the exposure to indoor air pollutants. Discussion Poor indoor air quality should be part of a comprehensive assessment of factors influencing mental health and cognition. Neuroinflammation might explain the effects of poor air on mental health and cognition. Further research is needed to combine research on the social determinants of mental health and the effects of indoor air. Studies in different settings such as home, work, and hospitals are needed to better understand the specific exposures of indoor air pollution and mental health conditions in different population groups.

The source of volatile organic compounds pollution and its effect on ozone in high-altitude areas

Volatile organic compounds (VOCs) are crucial precursors in the formation of ozone (O3). The sources of pollution are complex and significantly impact O3 generation. Long-term exposure to high-concentration O3 environments causes serious damage to organisms. High-altitude areas experience continuous high temperatures and strong solar radiation, which can easily produce O3 through photochemical reactions, making these areas prone to frequent air pollution. This study utilizes the National Positioning Station of the Yinchuan Urban Ecosystem in Ningxia to conduct field synchronous observations, gathering data on VOCs, meteorological variables, and O3. By employing machine learning algorithms, we examined the seasonal distribution characteristics of VOCs, their pollution sources, and their impact on O3. The results show that the seasonal distribution of VOCs areas is low in spring and autumn and high in summer and winter. The components with higher volume fraction contribution are m-tolualdehyde in spring and summer, ethane in autumn, and acetylene in winter. The main emission sources of VOCs pollution are hydrocarbon volatile emission in spring and winter, solvent volatilization emission in summer, and industrial sources in autumn. VOCs have a negative effect on O3, with a greater impact in winter and spring, evidenced by standardized effect values of -0.26 and -0.24. The key components affecting O3 in VOCs vary by season. Aromatic hydrocarbons are the key components in spring and winter, with contribution rates of 22 % and 21.3 %. Alkenes are the key components in summer and autumn (24.5 % and 26.8 %). Among meteorological variables, temperature is the key factor affecting O3, while wind speed is the key factor affecting O3 only in winter. This study aims to clarify the sources of VOCs pollution in different seasons and their impact on O3, providing a theoretical basis and technical support for the prevention and control of VOCs and O3 pollution in high-altitude areas.

Hygienic assessment of heavy metal and organic compounds pollution in snow cover of a multi-industrial city

Introduction. One of the leading health risk factors is atmospheric air pollution, the state of which can be indirectly assessed by the content of a wide range of pollutants in snow and soil cover. Materials and methods. The study analyzed data on deposits of polycyclic aromatic compounds (PAHs), heavy metals (HMs) and petroleum hydrocarbons (PHs) in the snow of different functional zones of the agglomeration. Physicochemical research methods were used. Results. The content of ΣPAHs was found to range from 412.8 to 2843.7 ng/L. The highest concentrations of ∑PAHs were observed in the residential area in the square (point 10) – 2843.7 ng/L; and on the border of the sanitary protection and residential zones in the area of the Yuzhnaya station (point 3) – 1758.2 ng/L. The share of benzo(a)pyrene (B(a)P) from ∑PAH ranged from 2.9 to 9.7%. PHs levels ranged from 51.0–117.0 μg/L. The difference in the range of fluctuations in values was most evident in the content of individual PAHs: B(a)P (16.13 times), Ant (12.05 times) and B(g,h,i)P (11.56 times ), mercury (17.53 times), zinc (9 times) and manganese (8.58 times); metals: cadmium (1.89 times), copper (1.75 times), and lead (1.47 times). Limitations. Sampling and features of snow cover contamination by atmospheric precipitation in the dynamics of the winter season. Conclusion. Concentrations of PAHs and HM varied in different ranges of values and had a non-uniform spatial distribution over the territory. Direct links were found between the content of B(a)P and other polyarenes in the snow cover.

Spatial heterogeneity of volatile organic compound pollution in a typical industrial park based on multi-point online monitoring: Pollution characteristics, health risks, and priority-controlled species

Spatial heterogeneity of volatile organic compound pollution in a typical industrial park based on multi-point online monitoring: Pollution characteristics, health risks, and priority-controlled species

Enhancing Oxygen Activation Ability by Composite Interface Construction over a 2D Co3O4-Based Monolithic Catalyst for Toluene Oxidation.

Developing robust metal-based monolithic catalysts with efficient oxygen activation capacity is crucial for thermal catalytic treatment of volatile organic compound (VOC) pollution. Two-dimensional (2D) metal oxides are alternative thermal catalysts, but their traditional loading strategies on carriers still face challenges in practical applications. Herein, we propose a novel in situ molten salt-loading strategy that synchronously enables the construction of 2D Co3O4 and its growth on Fe foam for the first time to yield a unique monolithic catalyst named Co3O4/Fe-S. Compared to the Co3O4 nanocube-loaded Fe foam, Co3O4/Fe-S exhibits a significantly improved catalytic performance with a temperature reduction of 44 °C at 90% toluene conversion. Aberration-corrected scanning transmission electron microscopy and theoretical calculation suggest that Co3O4/Fe-S possesses abundant 2D Co3O4/Fe3O4 composite interfaces, which promote the construction of active sites (oxygen vacancy and Co3+) to boost oxygen activation and toluene chemisorption, thereby accelerating the transformation of reaction intermediates through Langmuir-Hinshelwood (L-H) and Mars-van Krevelen (MvK) mechanisms. Moreover, the growth mechanism reveals that 2D Co3O4/Fe3O4 composite interfaces are generated in situ in molten salt, inducing the growth of 2D Co3O4 onto the surface lattice of 2D Fe3O4. This study provides new insights into enhancing oxygen activation and opens an unprecedented avenue in preparing efficient monolithic catalysts for VOC oxidation.

Green synthesis of a superhydrophobic porous organic polymer for the removal of volatile organic compounds at high humidity

Superhydrophobic porous organic polymers are potential sorbents for volatile organic compounds (VOCs) pollution control by suppressing the competition of water molecules on their surfaces. However, the synthesis of superhydrophobic reagents usually requires large amounts of organic solvents and a long reaction time (≥ 24h). Herein, a green mechanochemical method was developed to synthesize a superhydrophobic polymer (MSHMP-1) with the advantages of using a small amount of organic solvents (5mL/g) and a short reaction time (2h). Meanwhile, MSHMP-1 with a water contact angle (WCA) of 162° exhibited a dramatically rich pore structure as revealed by its specific surface area (SSA) of 1780 m2/g. The decrease in the adsorption of benzene on MSHMP-1 due to the competition of water molecules, even at relative humidity of 90%, was nonsignificant (<10%), indicating the great application potential of MSHMP-1 in hydrophobic adsorption. Moreover, the adsorption capacity of MSHMP-1 was maintained after at least five adsorption-desorption cycles. Therefore, MSHMP-1 can be a remarkable adsorbent for the removal of hazardous VOCs, especially at high humidity levels.

Study of Using a Phyto-nanosynthesis of Silver and Portulaca Oleracea Plant Extracts in Petroleum Spots Treatment

Petroleum spots has become a major global problem not only in terms of its increase, but also how it is treated, recycled or utilized. It contains suspended and dissolved solids, hydrocarbons and many types of organic matter and heavy metals. The reuse of petroleum spots faces the problem of removing organic pollutant compounds before discharging them into any natural stream. in this study, natural nano –coagulant material was used and their efficiency in removing turbidity, Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD) from petroleum spots were compared. The study was conducted in the laboratories of the Ecology Sciences Department, University of Kufa, Iraq in 2022. By synthesizing Phyto-nanosilver as a Phyto-nano silver from Leaves of Portulaca oleracea plant extracts used to reduce turbidity and organic pollutants of the petroleum spots. Jar test experiments showed that 0.5 mg / L Phyto-nanosilver dose can remove 95.5 % of (COD), 87.3% of TOC and 85.2 % from turbidity. Also, removal of P. oleracea plant extracts in the 1 and 0.5 mg/L dose can removed turbidity, COD and TOC content of 91.9%, 87.5 % and 82.4% respectively of the petroleum spots. Moreover, when using the nano-sliver only, removal of TOC, COD, and turbidity would reach 75.3%, 80.4%, and 81.3 %, respectively. The results of the research showed the efficiency of Phyto-nano silver materials in treating and depositing pollutants without harming the environment.

Migration Behaviour of the Combined Pollutants of Cadmium and 2,2′,4,4′,5,5′-Hexabrominated Diphenyl Ether (BDE-153) in Amaranthus mangostanus L. and Their Toxicity to A. mangostanus

The effects of different concentrations of cadmium and 2,2′,4,4′,5,5′-hexabrominated diphenyl ether (BDE-153) on the growth and related physiological and biochemical indexes of Amaranthus mangostanus L. (amaranth) were studied. The results showed that the presence of BDE-153 promoted the absorption of Cd by the amaranth and inhibited the migration of Cd from the roots to the shoots. At the same time, 0.1 mg/L of Cd had a synergistic effect on the migration of BDE-153, but 5 mg/L Cd inhibited the accumulation of BDE-153 in the aboveground part of the amaranth. In addition, the kinetics of the uptake of pollutants by the amaranth showed that both Cd and BDE-153 could be transported by amaranth, but Cd and BDE-153 were mainly enriched in the roots, and the presence of Cd may cause a lag in the uptake of BDE-153 in the shoots. Compared with the control group, the biomass of the amaranth affected by BDE-153 and a high concentration of Cd (5 mg/L) decreased by 30.2–49.5%, the chlorophyll content decreased by 43.0–60.3%, the Evans blue increased, and the MDA content was higher. The activities of superoxide dismutase (SOD) and catalase (CAT) also decreased with an increase in the BDE-153 concentration. This indicates that the interaction between BDE-153 and a high concentration of Cd (5 mg/L) is more toxic to amaranth than single Cd pollution. This paper provides the necessary data support for phytoremediation of heavy metal and organic compound pollution.

High-solution emission characters and health risks of volatile organic compounds for sprayers in automobile repair industries.

The increasing automobile repair industries (ARIs) with spray facilities have become an important volatile organic compound (VOC) pollution source in China. However, the VOC health risk assessment for long-term exposure in ARIs has not been well characterized. In this study, though sampled VOCs from 51 typical ARIs in Beijing, the relationship between emission patterns, average daily exposure concentrations (EC), and health risks was comprehensively analyzed with the health assessment method. Results showed that concentrations of 117 VOCs from the samples ranged from 68.53 to 19863.32 μg·m-3, while the ARI operator's daily VOC inhalation EC was 11.24-1460.70 μg·m-3. The organic VOC (OVOC) concentration accounted for 73.16 ~ 94.52% in the solvent-based paint workshops, while aromatics were the main VOC component in water-based paint spraying (WPS) workshops, accounting for 70.08%, respectively. And the method of inhalation exposure health risk assessment was firstly used to evaluate carcinogenicity and non-carcinogenicity risk for sprayers in ARIs. The cumulative lifetime carcinogenic risk (LCR) for 24 sampled VOCs were within acceptable ranges, while the mean hazard index (HI) for 1 year with 44 sampled VOCs was over 1. Among them, ethyl alcohol had a high carcinogenic risk in both mixed water-based paint (MP) and solvent-based paint workshops. The mean HI associated with aromatics were 2.88E - 3 and 4.30E - 3 for 1 h in MP and WPS workshops. O-ethyl toluene and acetone are VOC components that need to be paid attention to in future paint raw materials and spraying operations. Our study will provide the important references for the standard of VOC occupational exposure health limits in ARIs.

A prediction index of the volatile organic compounds pollution conditions in a chemical industrial park based on atmospheric stability

Volatile organic compounds (VOCs), as common precursors of ozone (O3) and fine particulate matter (PM2.5), are a focus of air pollution prevention and control. Furthermore, with the rapid development of industry, industrial sources have become the largest source of anthropogenic VOCs emissions, leading to economic development while causing great harm to the environment. It is becoming meaningful to efficiently predict the future total volatile organic compounds (TVOC) pollution conditions in chemical industrial parks (CIPs), which can assist managers in carrying out corporate emission management in advance. In this study, TVOC monitoring data and meteorological data from January 1, 2022, to December 31, 2022, were used to innovatively construct the TVOC pollution index. This index comprehensively considers the atmospheric stability and localized horizontal diffusion conditions and can quickly and accurately predict the variations in the TVOC in a CIP in the next 7days. In addition, we used synoptic weather patterns and backward trajectory analysis to explore the mechanism of VOCs pollution formation in a CIP. The results show that the combined influences of a westerly wind pattern, temperatures above 30°C, a subtropical high pressure system, more upwind pollutants, and the horizontal and vertical diffusion conditions in the CIP were unfavorable, leading to VOCs pollution.

Performance enhancement analysis of a liquid desiccant dehumidifier with internal cooling for indoor benzene removal

Performance enhancement analysis of a liquid desiccant dehumidifier with internal cooling for indoor benzene removal

Conversion of waste cork to N-doped porous carbons by urea-assisted hydrothermal method for enhanced VOC capture

Converting waste resources into porous carbon for pollutants capture is an effective strategy to achieve the environmental goal of "treating waste with waste". Cork is an ideal precursor of porous carbons due to its ordered honeycomb-like cell structure and layered composition distribution. Herein, N-doped porous carbons (PCs) were prepared via two steps of urea-assisted hydrothermal carbonization and chemical activation to mitigate volatile organic compounds (VOCs) pollution. Results indicated that the obtained PC4-800 exhibited remarkable features for adsorption including high total pore volume (0.97cm3/g) and specific surface area (1864.89m2/g), as well as abundant N-containing functional groups. The excellent pore structure was primarily owing to the corrosion of the carbon matrix by the gas produced from the reaction of K2CO3 and N-containing functional groups. The adsorption results showed that the PC4-800 have an outstanding toluene adsorption capacity (867.03mg/g) that outperforming majority of adsorbents previously reported. There are substantial pores in N-doped PCs with a pore width of 1.71-2.28nm, which is 3 to 4 times the molecular dynamic diameter of toluene, and plays a crucial role in the absorption process. Moreover, the promotional influence of N-functional groups on the toluene adsorption process was verified through DFT calculation by Gaussian imitating, where N-6 generated π-electron enrichment sites on the surface of N-doped PCs, facilitating π-π dispersion with the benzene ring in toluene. This study provides a new strategy to convert waste cork into high-performance adsorbents for VOCs removal.

Bimetallic MOF derived mesoporous structure of Ru doped SnO2 enable high-sensitivity gas sensors for triethylamine in high humidity

Bimetallic MOF derived mesoporous structure of Ru doped SnO2 enable high-sensitivity gas sensors for triethylamine in high humidity

Luffa Cylindrica Fibers Unveiled: A Sustainable Approach for 4-Nitrophenol Removal in Aqueous Solutions through Activated Carbon Utilization

The prevalence of mutagenic and highly toxic compounds, such as 4-Nitrophenol (4-NP) and its derivatives, in industrial wastewater poses a significant environmental threat. This study emphasizes the critical need for public authorities to prioritize combating organic compound pollution for achieving sustainable development. The focus of this research is the preparation and evaluation of activated carbon adsorbents derived from Luffa cylindrica fibers (LC) for the efficient removal of 4-NP from aqueous solutions. The preparation involved carbonization process by heating LC in an argon furnace at 800℃, resulting in carbonized Luffa cylindrica fibers (LCC). Subsequently, chemical activation is performed using potassium hydroxide (KOH) solution, denoted as LCA. The properties of the adsorbent are identified through X-Ray Diffraction (XRD). To assess the removal efficiency of 4-NP, various parameters such as pH, adsorbent dosage, and 4-NP solution concentration are investigated. Optimal conditions for maximum 4-NP removal are achieved at a concentration of 50 mg/L, an adsorbent dosage of 0.75 mg/L (LCA), and a solution pH of 5. These conditions result in an impressive 99 % removal of 4-NP in 60 minutes. This study demonstrates the feasibility of utilizing locally available raw materials, such as LC fibers, to prepare an adsorbent with a robust adsorptive capacity for toxic pollutants like 4-NP. The findings underscore the potential of eco-friendly solutions in addressing environmental challenges and promoting sustainable practices in wastewater treatment.

Impact of Surrounding Infrastructure on Urban Environment: A Case Study of Karachi Metropolitan

Urban environment carries complex land-use and land cover (LULC), similarly Karachi as a metropolitan have multifaceted LULC and compact infrastructure. This study seeks to assess the impact of infrastructure of urban environment at mega city Karachi Pakistan. Approximately, fifteen different locations of metropolitan with different surroundings were evaluated based on the studied variables of surrounding such as temperature, humidity, formaldehyde (HCHO), total volatile organic compounds (TVOC) pollution, fine particulate matter (PM2.5) in air i.e., air quality, maximum noise pollution and minimum noise pollution were investigated. The readings have been collected through relevant instruments and the results have been generated through interpolation in ArcMap 10.8. The obtained results revealed that the physical factors affect the temperature and humidity conditions of the study area. While environmental and noise pollution depends on the surroundings, e.g. industrial surrounding effects on air quality, i.e. 180 recorded at industrial region of Korangi, while construction sites are catalysts of noise pollution and highest noise pollution are recorded at North-Nazimabad. Cancer causing substance, i.e. formaldehyde found along the petrol pumps, airports and transportation junctions ranges up to 0.99 ppm near Jinnah International airport and mass transit location of Shahrah e Faisal. While total volatile compound pollution has been found along the Malir catchment area, i.e. 0.4 mg/m3. The lifestyle of Karachiites need to be transform there is a dire need to think about physical and mental concord of the citizens of metropolitan. Similarly, government should play some positive actions and introduced green and environmental friendly technology to control air and noise pollution.

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.