Volatile Organic Compounds Research Articles

Distribution and Risk Assessment of VOCs in Road Dust Across Different Urban Areas

ABSTRACT Volatile organic compounds (VOCs) are significant pollutants in urban road dust, but their distribution and associated health risks remain unclear. VOC distribution in road dust from six distinct urban areas in Beijing Daxing District, China was systematically investigated. Eighteen VOCs were detected, with the highest load in commercial areas (7.73 μg/g), followed by industrial parks (6.38 μg/g), residential areas (3.35 μg/g), leisure areas (2.79 μg/g), traffic areas (2.01 μg/g) and urban-rural fringe (1.85 μg/g), much lower than in air and water phases. Typical VOCs in road dust include methyl tertiary butyl ether (MTBE) (0.82–1.24 μg/g), benzene series compounds (0.02–4.19 μg/g) and volatile halogenated alkanes (0.002-0.095 μg/g). Incomplete combustion of road vehicle fuels is the key source of VOCs. Particular attention was given to VOCs in typical sites within the urban-rural fringe, known for their unique pollution characteristics. The VOCs loads were ranked as follows: Gas Stations (2.61–2.62 μg/g) > Intersection (1.41 μg/g) > Main Road (1.34 μg/g) > University Gate (1.27 μg/g). Increased vehicle activity and frequent stalling contribute to higher VOCs accumulation in road dust. Health risk assessment indicates there is no appreciable non-carcinogenic risk associated with exposure to road dust VOCs. Further research should consider VOCs in the broader environmental context, including air and water.

Exposure to volatile organic compounds and growth indicators in adolescents: Unveiling the association and potential intervention strategies

Environmental pollutant is considered to be one of the important factors affecting adolescent growth. However, the effects of volatile organic compounds (VOCs) exposure on adolescent growth have not been assessed. Data from the National Health and Nutrition Examination Survey (NHANES) 2011-2018 was used to examine the associations between VOCs exposure and adolescent growth indicators through three statistical models. The mediating effect of bone mineral density (BMD) on these associations was examined. The potential pathways and key targets were identified by the network pharmacology analysis methods. This study included 746 adolescents. Three statistical methods consistently showed a negative correlation between VOCs exposure and adolescents growth indicators. Furthermore, BMD mediated the relationship between VOCs exposure and adolescent growth indicators, with mediated proportion ranging from 4.3% to 53.4%. Network pharmacology analysis found a significant enrichment in IL-17 signaling pathway. Moreover, the adverse effects of VOCs exposure on adolescent growth were observed to significantly attenuate in adolescents with high serum vitamin D levels. Our results suggested that VOCs exposure was an adverse factor affecting adolescent growth, with BMD playing a significant regulatory role, and IL-17 signaling pathway was the underlying mechanism. Vitamin D supplementation may be a viable strategy to prevent VOCs exposure from affecting adolescent growth. Environmental implicationVolatile organic compounds (VOCs), a group of pollutants pervasive in daily life, are absorbed by the human body in various ways, resulting in the occurrence of various diseases. The results of this study suggested that VOCs exposure may affect adolescent growth, with bone mineral density playing an important mediating role, and IL-17 signaling pathway was the potential mechanism. Vitamin D may be a potential intervention strategy to prevent the adverse effects of VOCs on adolescent growth. Our results not only revealed the potential relationship and mechanism between VOCs exposure and adolescent growth, but also provided a potential intervention strategy.

A quantitative comparison of economic viability, volatile organic compounds, and particle-bound carbon emissions from a diesel engine fueled with biodiesel blends

Despite the environmental advantages of biofuel blends, detailed studies on emissions of polycyclic aromatic hydrocarbons (PAHs), n-alkanes, and particle-bound carbon from diesel engines, particularly when fueled with biodiesel, remain limited. This study addresses these gaps by analyzing biodiesel blends from neem, linseed, and jatropha oils produced via mechanical extraction and assessing their impact on volatile organic compounds and particle-bound carbon emissions in diesel engine. Economic evaluations of production costs, engine modifications, and payback periods are also conducted. The result shows that jatropha biodiesel exhibits a calorific value of 35.7 MJ/kg, while neem biodiesel shows superior oxidative stability due to its low iodine value. Additionally, linseed biodiesel displays favorable cold flow properties due to its high density and cetane value. Compared to D100, the N10 and N30 blend notably reduced high molecular weight PAH emissions by 10.7% and 38.4%, respectively, with the N30 blend achieving a remarkable 76% reduction in formaldehyde emissions. Conversely, the J10 blend increased specific PAHs, while the J30 blend reduced PAHs by 21.3%. Both L10 and L30 blends showed reduced naphthalene emissions, with the J30 blend notably reducing elemental carbon (EC) by 31.4%, although organic carbon (OC) slightly increased. In contrast, the N30 blend decreased both EC and OC emissions, demonstrating a dose-dependent relationship between biodiesel concentration and emissions reduction. Overall, Jatropha biodiesel blends offer the best balance of economic efficiency and emission reductions, resulting in shorter payback periods and lower carcinogenic risks. Neem and linseed blends also provide environmental benefits but with varying economic implications, highlighting the trade-offs between production costs and long-term sustainability.

Enhanced waste water purification performance of solar-driven interfacial water evaporation through the integration of electrocatalysis

Solar-driven interfacial water evaporation (SDIWE) has been proven to be an effective method for purifying polluted water. However, the challenging issue of removing volatile organic compounds (VOCs) from wastewater is frequently encountered. In this study, the SDIWE-electrocatalysis coupling system is established by employing defective TiO2 as both photothermal and electrode materials, and significant enhancements are achieved in terms of water evaporation rate and distilled water quality. The application of voltage not only generates joule heat but also reduces water evaporation enthalpy, contributing to the improved water evaporation rate. Under solar irradiation of 1.0 kW·m−2, the water evaporation rate increases from 1.43 kg·m−2·h−1 at 0 V to 1.63 kg·m−2·h−1 at 2.0 V. With the utilization of Ti@R-TiO2 foam as the anode and Ti@TiO2 foam as the cathode, it becomes feasible to directly oxidize VOCs at the anode and electrocatalytically reduce O2 at the cathode. Consequently, the VOCs can be effectively eliminated from distilled water. Applying 2.0 V under 1.0 kW·m−2 with oxygen inlet, approximately 25 % removal efficiency was achieved through electrolysis-SDIWE coupling system. This study's approach combining electrolysis with SDIWE presents a promising avenue for advancing SDIWE technology in order to achieve efficient wastewater treatment.

Effect of surfactant type and concentration on the gas-liquid mass transfer in biotrickling filters used for air pollution control

Volatile organic compounds (VOCs) emitted into the atmosphere negatively affect the environment and human health. Biotrickling filtration, an effective technology for treating VOC-laden waste gases, faces challenges in removing hydrophobic VOCs due to their low water solubility and therefore limited bioavailability to microorganisms. Consequently, the addition of (bio)surfactants has proven to be a promising strategy to enhance the removal of hydrophobic VOCs in biotrickling filters (BTFs). Yet, up to now, no single study has ever performed a mass transfer characterization of a BTF under (bio)surfactants addition. In this study, the effect of (bio)surfactant addition on the gas-liquid mass transfer characteristics of two BTFs was measured by using oxygen (O2) as a model gas. Through an empirical correlation, the mass transfer coefficients (kLa) of two hydrophobic VOCs, toluene and hexane, which are of industrial and environmental significance, were estimated. One BTF was filled with expanded perlite, while the other with a mixture of compost and wood chips (C+WC). Both BTFs were operated under different liquid velocities (UL: 0.95 and 1.53 m h-1). Saponin, a biological surfactant, and Tween 80, a synthetic surfactant, were added to the recirculating liquid at different critical micelle concentrations (CMCs: 0 - 3 CMC). The higher interfacial and surface area of the perlite BTF compared to the C+WC BTF led to higher kLaO2 values regardless of the operational condition: 308±18 - 612±19 h-1 versus 42±4 - 177±24 h-1, respectively. Saponin addition at 0.5 and 1 CMC had positive effects on the perlite BTF, with kLaO2 values two times higher compared to those at 0 CMC. Tween 80 exhibited a neutral or slightly positive effect on the mass transfer of both BTFs under all conditions. Overall, the CMC, along with the physical characteristics of the packing materials and the operational conditions evaluated explained the results obtained. This study provides fundamental data essential to improve the performance and design of BTFs for hydrophobic VOCs abatement.

3D Hydrophobic Wood Membrane with Micro-nano Baffle Structure for Multifunctional Air Purification Filters: “Kill three eagles with one arrow”

Air pollution has presented an imminent threat to the world. Multifunctional filters with high filtration efficiency, low pressure drop, moisture resistance, antibacterial properties, and renewability are urgently needed to be developed. In this study, multifunctional wood filters are innovatively designed with a baffle structure combining macroscopic structural design and microscopic in-situ synthesis of silver nanoparticles (Ag NPs). The filter has excellent particle removal efficiency (PM0.3, 98.5%), exceptional volatile organic compounds (VOCs) adsorption efficiency (98.4% for formaldehyde and 91.7% for xylene), high sterilization efficiency (99.99%) and excellent regeneration ability (performance recovery to 98% of the initial). Furthermore, personal protective masks were assembled by the prepared filters, whose process of replacing element is as simple as replacement of electric mosquito incense tablets. This innovative filter holds promise for applications such as daily protection, sudden accidents and prevention and control of respiratory infectious diseases. We envision that the functionally modified Ag NPs wood filters with a multilayer structure offer a comprehensive solution for more effective air purification in polluted environment.

High-quality utilization of reclaimed asphalt pavement (RAP) in asphalt mixture with the enhancement of steel slag and epoxy asphalt

Achieving high-quality utilization of reclaimed asphalt pavement (RAP) is challenging due to the subpar technical performance of aggregates and the aging of asphalt within RAP. This study investigates the use of epoxy asphalt (EA) and steel slag to enhance recycled asphalt mixtures (RAM) for superior performance and increased RAP content. The rheological performance of epoxy asphalt (EA) was evaluated using a dynamic shear rheometer (DSR), and its curing process was analyzed. Steel slag-epoxy recycled asphalt mixtures (SRAM) with 40 %, 80 %, and 100 % RAP were prepared, and their road performance was assessed through Marshall, wheel tracking, and semi-circular bending tests. Additionally, the effects of steel slag’s surface morphology and element distribution on moisture and skid resistance were examined. The volatile organic compound (VOC) emission characteristics were also studied. The results show that EA forms a uniformly dispersed structure, providing excellent high-temperature deformation resistance. EA and steel slag significantly enhanced the road performance of SRAM, with SRAM-80 (80 % RAP, 20 % steel slag) achieving a dynamic stability of 15027 times/mm. Steel slag improved SRAM-80’s skid resistance, with a British pendulum number (BPN) of 68 and a texture depth (TD) of 0.5889 mm. Compared to 60/80 asphalt, EA reduced VOC emissions by over 75 %. Incorporating 80 % RAP and 20 % steel slag into RAM effectively utilizes RAP while enhancing performance.

Unraveling the toluene adsorption mechanism of MIL-101(Cr) derived from PET waste for COV removal applications

Herein, we provide a study on the removal of volatile organic compounds (VOCs) using a metal-organic framework MIL-101(Cr) derived from PET waste, denoted as MIL-101(Cr)-PET. As a model molecule for VOCs frequently found in indoor air, toluene was used. The characteristics and adsorption efficiency of both conventional MIL-101(Cr), denoted as MIL-101(Cr)-BDC, and environmentally friendly MIL-101(Cr) powders were evaluated and compared using a range of techniques in our research, including PXRD, HAADF-STEM, TGA, BET, and adsorption studies. MIL-101(Cr)-PET exhibits crystal structure and thermal stability similar to the conventional MIL-101(Cr) synthesized using a commercially available organic linker. Differently, it displayed relatively agglomerated smaller particles and a reduced surface area, attributed to the absence of any modulator and the use of PET waste as the source of the organic linker. Nevertheless, similar toluene adsorption performance was obtained in both batch and continuous adsorption setups. Furthermore, the adsorption mechanism was elucidated by means of molecular simulation, identifying two distinct adsorption sites. At low toluene concentrations, the preferred site was within the small cage due to pore size constraints, while at saturation, the most likely conformation involved parallel offset staking. These results suggest the occupancy of less energetically favorable sites and volumetric filling at higher concentrations.

Case Study: Advanced Technology Underpins Efficiency and Climate-Related Goal Gains

_ Today’s gas-compression operators are under increasing pressure to reduce greenhouse gas (GHG) emissions. Fortunately, multiple technologies are available that can support that objective while enabling operators to move more gas cost-effectively. Embracing such advancements can positively impact a reduced-carbon future without compromising operational efficiency or profitability. To choose the right technologies for a gas-compression package, it’s critical for operators to have a clear understanding of their business and GHG emissions-related goals. Operators also need clarity concerning the impact of evolving requirements on total cost of ownership (TCO) as well as potential financial ramifications. Producing more gas at a lower cost with lower GHG emissions is possible with new technologies. Operators can support their success by choosing the right engine driver for a gas-compression package based on their unique needs and site conditions. It’s critical to consider an engine’s power density and TCO, as that informs an operator’s selections and can lower a gas-compression package’s operating cost in terms of dollars per thousand cubic feet ($/Mcf) of gas throughput. An engine, such as the Cat G3600 A4 Gen 2, that can deliver a 10% power increase compared to the previous model can allow operators to use fewer engines to perform the same amount of work. This advantage can lower capital requirements, reduce operating expenses, and decrease fuel consumption. Fewer engines operating in the field may also contribute to lower GHG emissions. Modernizing Existing Assets Operators prioritize flexibility, durability, and lower TCO. They can support those objectives by choosing an engine platform that allows performance upgrades across the life of the engine. This enables operators to apply advanced technology in their existing fleet year after year without incurring the substantial cost of purchasing a new engine. Engine upgrade kits offer operators an option to maximize and modernize active assets in a streamlined way, as the upgrades can be applied conveniently and cost-effectively at the time of a scheduled overhaul to minimize disruption. For example, by using an upgrade kit for an A4 Gen 1 engine model referenced above, operators can lower volatile organic compounds up to 32%, formaldehyde up to 24%, carbon monoxide up to 13%, methane emissions up to 33%, and total GHG emissions up to 5% on a grams per brake horsepower-hour (g/bhp-hr) basis* while saving the traditional capital expenditure of a new engine. (*Site conditions: Same power level between the G3600 A4 Gen 1 and Gen 2, 85MN, 905 BTU/scf, 100% load, 25°C ambient, 500-ft altitude.) Such updates are relatively cost neutral when applied as part of a scheduled major overhaul and require minimal or no change to the compression package. This makes upgrade kits a wise choice to ensure equipment keeps pace with industry demands.

Adsorption of Typical VOCs Onto Ti2CO2 MXene with Implications in Early‐Stage Lung Cancer Diagnosis: A DFT Study

AbstractIn this work, Ti2CO2 MXene is employed as a sensing material to detect volatile organic compounds (VOCs). Using Density Functional Theory (DFT) calculations, the adsorption properties of toluene, isopropanol, formaldehyde, and acetonitrile are calculated and compared. The electronic properties are analyzed to gain insight into the adsorption mechanism. Additionally, the recovery time and sensitivities are studied to evaluate the sensing performance of Ti2CO2 in detecting these VOCs. The results show that the four molecules undergo physisorption. Bader charge analysis shows a small charge transfer from the molecules to the MXene material. The adsorption of these molecules induces changes in the electronic properties of Ti2CO2, particularly in terms of resistance and work function. These changes are used to estimate the sensing response of this material toward these VOCs. Notably, the results highlight that Ti2CO2 exhibits good sensitivity and selectivity, especially in the case of isopropanol. These findings demonstrate the ability of Ti2CO2 as a sensing material for detecting VOCs for the early diagnosis of cancer.

Harvest Initiated Volatile Organic Compound Emissions from In-Field Tall Wheatgrass

Harvest Initiated Volatile Organic Compound Emissions from In-Field Tall Wheatgrass

Assessment of potential health impact of volatile organic compounds of underground water samples around fuel station in Okinni area Osogbo, Osun State, Nigeria

Assessment of potential health impact of volatile organic compounds of underground water samples around fuel station in Okinni area Osogbo, Osun State, Nigeria

Indoor Emission, Oxidation, and New Particle Formation of Personal Care Product Related Volatile Organic Compounds

Indoor Emission, Oxidation, and New Particle Formation of Personal Care Product Related Volatile Organic Compounds

Thermal Annealing Effects on Long-lived Fluorenol Room Temperature Phosphorescence for Styrene Detection.

Fluorene derivatives have been widely developed in OLEDs because of its efficient fluorescence quantum efficiency, but for which unique rigid biphenyl planar structure and large conjugated system, we hypothesize that they have a great potential for room temperature phosphorescence (RTP) applications, and confirmed this conjecture by subjecting polyvinyl alcohol (PVA) and phosphors to thermal annealing. The cross-linked structure formed during thermal annealing judiciously modulates the phosphorescence emission characteristics of the fluorenol with the synergistic interaction between PVA and fluorenol. Specifically, the lifetime exhibited a substantial increase from 1352.2 ms to 2874.1 ms, accompanied by a quantum yield augmentation from 4.8% to 11.3%, which substantiate that cross-linked induced by thermal annealing effectively amplifies the phosphorescent intensity and stability of the phosphors, facilitating ultralong phosphorescent emission at ambient conditions. Furthermore, an effective probe based on this film is developed for its highly sensitive, quantitative and immediate detection of volatile organic compounds. This investigation not only proffers a novel paradigm for the development of advanced RTP materials but also imparts insightful considerations for optimizing the performance of polymers in conjunction with functional materials, encompassing bioimaging, sensing, and optoelectronic devices.

Using observed urban NOx sinks to constrain VOC reactivity and the ozone and radical budget in the Seoul Metropolitan Area

Abstract. Ozone (O3) is an important secondary pollutant that impacts air quality and human health. Eastern Asia has high regional O3 background due to the numerous sources and increasing and rapid industrial growth, which also impacts the Seoul Metropolitan Area (SMA). However, the SMA has also been experiencing increasing O3 driven by decreasing NOx emissions, highlighting the role of the local in situ O3 production on the SMA. Here, comprehensive gas-phase measurements collected on the NASA DC-8 during the National Institute of Environmental Research (NIER)/NASA Korea–United States Air Quality (KORUS-AQ) study are used to constrain the instantaneous O3 production rate over the SMA. The observed NOx oxidized products support the importance of non-measured peroxy nitrates (PNs) in the O3 chemistry in the SMA, as they accounted for ∼49 % of the total PNs. Using the total measured PNs (ΣPNs) and alkyl and multifunctional nitrates (ΣANs), unmeasured volatile organic compound (VOC) reactivity (R(VOC)) is constrained and found to range from 1.4–2.1 s−1. Combining the observationally constrained R(VOC) with the other measurements on the DC-8, the instantaneous net O3 production rate, which is as high as ∼10 ppbv h−1, along with the important sinks of O3 and radical chemistry, is constrained. This analysis shows that ΣPNs play an important role in both the sinks of O3 and radical chemistry. Since ΣPNs are assumed to be in a steady state, the results here highlight the role that ΣPNs play in urban environments in altering the net O3 production, but ΣPNs can potentially lead to increased net O3 production downwind due to their short lifetime (∼1 h). The results provide guidance for future measurements to identify the missing R(VOCs) and ΣPN production.

Recent advances in solid phase microextraction with various geometries in environmental analysis.

Solid phase microextraction (SPME) has emerged as a versatile sample preparation technique for the preconcentration of a broad range of compounds with various polarities, especially in environmental studies. SPME has demonstrated its eco-friendly credentials, significantly reducing the reliance on solvents. The use of biocompatible materials as a coating recipe facilitates the acceptance of SPME devices in analytical chemistry, primarily in the monitoring of environmental pollutants such as persistent organic pollutants (POPs), volatile organic compounds (VOCs), and pesticides from the various environmental matrices. During the last few years, investigators have reported an improvement in the SPME enrichment technique after changing the coating recipe, geometries, and sampling procedure from the complex matrices. Furthermore, the development of various geometries of SPME with large surface areas has enhanced the extraction efficiency of environmental pollutants. As a miniaturized sample preparation technique, SPME significantly reduces the solvent usage, suggesting a potential platform for green chemistry-based research for water, air, and soil analysis. This review article summarizes the evolution of SPME, its various modes, the application of SPME, recent innovations, and prospects for the determination of water, air, and soil pollution. The advantages and disadvantages of SPME in comparison to other extraction techniques have been discussed here. This review serves as a valuable resource for investigators working in sustainable environmental research.

Gas Chromatography–Mass Spectrometry Analysis of Volatile Organic Compounds from Three Endemic Iris Taxa: Headspace Solid-Phase Microextraction vs. Hydrodistillation

Gas Chromatography–Mass Spectrometry Analysis of Volatile Organic Compounds from Three Endemic Iris Taxa: Headspace Solid-Phase Microextraction vs. Hydrodistillation

Temporal Variation and Industry-Specific Differences of the Use of Volatile Organic Compounds from 2018 to 2023 and Their Health Risks in a Typical Industrially Concentrated Area in South China

Temporal Variation and Industry-Specific Differences of the Use of Volatile Organic Compounds from 2018 to 2023 and Their Health Risks in a Typical Industrially Concentrated Area in South China

The Role of Volatile Organic Compounds (VOCs) in Determining Seed Physiological Quality: A Review

Volatile organic compounds (VOCs) emitted by seeds serve as promising biomarkers for assessing seed vigor, viability, and deterioration during storage. This review synthesizes current knowledge on the types and chemical classes of VOCs released by seeds, factors affecting their emission, and methods for their collection and analysis. VOCs indicate seed aging, with increased emissions of alcohols, aldehydes, and ketones associated with deterioration processes like lipid peroxidation. Volatile organic compounds (VOCs) associated with seed deterioration include alcohols like ethanol, which can indicate fermentation, aldehydes such as hexanal, which is linked to lipid oxidation, and ketones like 2-heptanone, which can result from microbial activity and contribute to off-flavors and rancidity. The quantity and composition of VOCs correlate with the extent of seed deterioration, potentially offering a rapid, non-destructive alternative to traditional germination tests for evaluating seed quality. VOCs also mediate interactions between seeds and microorganisms, influencing germination and stress responses. Different research findings regarding volatile organic compounds (VOCs) in seeds indicate their potential as indicators of seed quality, which could lead to improved seed management strategies. By utilizing VOC profiling, farmers can make informed decisions on seed selection and treatment, ultimately enhancing crop yield and resilience in agricultural practices. While VOC analysis shows promise for integration into seed quality testing, challenges remain in standardizing protocols and identifying robust markers across different seed types, species and storage conditions. Advances in VOC research may ultimately lead to novel solutions for improving seed and crop productivity. Future research directions in VOC analysis for seed quality testing should focus on standardizing VOC profiles across diverse seed species, integrating VOC analysis with precision agriculture technologies, exploring environmental influences on VOC emissions, developing non-invasive testing methods, conducting longitudinal studies on seed storage, applying VOCs in breeding programs, and establishing links between VOC emissions and disease resistance.

Volatile organic compounds in exhaled breath of newborns: a pilot study.

To assess volatile organic compounds (VOCs) in breath samples collected non-invasively from preterm and full-term infants. This was a pilot study included preterm and full-term infants who were not intubated or suspected or diagnosed with metabolic or gastrointestinal disorders. The samples were analyzed for VOCs using a selected-ion flow-tube mass spectrometer. Twenty infants were included; ten preterm and ten full-term infants. Twenty-two VOCs were detected and measurable in all samples. There was a significant difference between preterm and full-term infants for the 2-propanol, acetaldehyde, acetone, acetonitrile, benzene, ethanol, isoprene, pentane, 3-methylhexane, 2-nonene, ethane, triethylamine, and trimethylamine compounds. It is feasible to measure VOCs in breath samples of preterm and full-term non-intubated infants. Full-term infants express different concentrations than preterm infants. Further studies are needed to examine the utility and reproducibility of measuring VOCs to identify neonatal diseases and predict outcomes.