Total Volatile Organic Carbon Research Articles

Impacts of varied industrial activities within southern Nigeria on air environment and human health

The contamination of air environment by industrial activities is a global problem mostly in the underdeveloped and developing Nations where environmental issues are handled with levity. This research investigated the impact of industrial activities on air environment at the following companies; Crude Oil processing (COPC), beer processing (BPC), asphalt processing (APC), metal processing (MPC), and construction Company machinery Yard (CCMY) in Southern Nigeria. Air Monitors were employed to quantify nitrogen (IV) oxide (NO2), sulphur (IV) oxide (SO2), hydrogen sulphide (H2S), cabon (II) Oxide CO, total volatile organic carbon (TVOC), and suspended particulate matter (SPM) at the studied locations. The mean values of NO2, SO2, H2S, and CO obtained at all the industrial locations were higher than their recommended limits by the Federal Environmental and protection Agency (FEPA) except at BPC. The mean levels of TVOC were higher than the limit at all the locations apart from BPC and CCMY. However, the mean levels of SPM at all locations were higher than the permissible limit. The general trend for the discharge of air pollutants indicated that, COPC and BPC were rated the highest and lowest, respectively. The air quality index (AQI) values obtained revealed that, all the air pollutants at all the locations except BPC were harmful to human health. Nevertheless, the mean AQI value of SPM at BPC was also in the hazardous class. The Principal component analysis (PCA) confirmed that, industrial activities at the studied locations were responsible for the accumulation of these toxic substances in the adjoining air environment. Hierarchical cluster analysis (HCA) for the air pollutants corroborated that most of the parameters were from a common source. HCA for the studied locations indicated similarities between BPC and CCMY, APC and MPC, while COPC was in a separate cluster. Thus, this study has shown the effects of untreated gases released from industries into the air on the environment and appropriate measures should be adopted to ameliorate the trend.

Regional VOC characterization, source profile and impact by a new technology of quick mass spectrometry navigation

The monitoring system used in this study can quickly display a volatile organic carbon (VOC) map of a given area and identify more than 100 gas components. In this study, mass spectrometry (MS) navigation technology was used to monitor VOCs in urban agglomerations in Central China. The proposed system could quickly monitor the total VOCs (TVOCs) in ambient air, and then the VOC compositions of pollution sources were further analysed. The experiment lasted for approximately 9 months, and it monitored of 33 regions and identified 286 VOC emission point sources. The average concentration of VOCs per monitored emission sites was 372 μg/m3, and the maximum peak value was approximately 10 mg/m3. We systematically analysed the pollution levels and components of VOCs in different regions of Central China and focused on the pollution emission characteristics of the four industrial regions. Aromatic hydrocarbons and oxygenated volatile organic compounds (OVOCs) were the most important emission components in Central China. Hotspots with high concentrations were mainly located in industrial areas, traffic intersections, and construction sites. Different industries had characteristic VOC concentrations and components. The furniture and coating industries produced the heaviest regional pollution, and OVOCs and aromatic hydrocarbons were the main pollutants. In the region dominated by the machinery industry, the main pollutants were aromatic hydrocarbons and alkanes. This study found that pollution in the Central Plains of China was higher in the north than the south. Therefore, the northern part of Central China has a greater impact on the neighbouring capital economic region.The bifurcation coefficient among background sites and emission sources further indicated that navigation monitoring technology can help researchers and managers quickly describe regional pollution distribution and discharge characteristics, identify key polluting industries and substances, determine regional contribution rates, and formulate targeted and precise governmental policies at the national and regional scale.

An Inversion Framework for Optimizing Non‐Methane VOC Emissions Using Remote Sensing and Airborne Observations in Northeast Asia During the KORUS‐AQ Field Campaign

We aim to reduce uncertainties in CH2O and other volatile organic carbon (VOC) emissions through assimilation of remote sensing data. We first update a three‐dimensional (3D) chemical transport model, GEOS‐Chem with the KORUSv5 anthropogenic emission inventory and inclusion of chemistry for aromatics and C2H4, leading to modest improvements in simulation of CH2O (normalized mean bias (NMB): −0.57 to −0.51) and O3 (NMB: −0.25 to −0.19) compared against DC‐8 aircraft measurements during KORUS‐AQ; the mixing ratio of most VOC species are still underestimated. We next constrain VOC emissions using CH2O observations from two satellites (OMI and OMPS) and the DC‐8 aircraft during KORUS‐AQ. To utilize data from multiple platforms in a consistent manner, we develop a two‐step Hybrid Iterative Finite Difference Mass Balance and four‐dimensional variational inversion system (Hybrid IFDMB‐4DVar). The total VOC emissions throughout the domain increase by 47%. The a posteriori simulation reduces the low biases of simulated CH2O (NMB: −0.51 to −0.15), O3 (NMB: −0.19 to −0.06), and VOCs. Alterations to the VOC speciation from the 4D‐Var inversion include increases of biogenic isoprene emissions in Korea and anthropogenic emissions in Eastern China. We find that the IFDMB method alone is adequate for reducing the low biases of VOCs in general; however, 4D‐Var provides additional refinement of high‐resolution emissions and their speciation. Defining reasonable emission errors and choosing optimal regularization parameters are crucial parts of the inversion system. Our new hybrid inversion framework can be applied for future air quality campaigns, maximizing the value of integrating measurements from current and upcoming geostationary satellite instruments.

Characterization of the Strength of a Natural Sand and Artificial Sand Core Manufactured with Inorganic Binder

Natural sand and organic binders are commonly used in casting processes, but these ingredients produce environmental problems with dust and harmful TVOC(Total Volatile Organic Carbon) gases. Research on the introduction of artificial sand and inorganic binders to solve these environmental problems is being actively conducted mainly in the casting industry. Artificial sand has superior durability and a spherical shape compared to natural sand, and above all, it does not generate dust. In addition, inorganic binders have the advantage that no harmful gas is generated during casting and the used sand can be recycled. This study confirmed whether inorganic binders can be applied when replacing natural sand with artificial sand. First, eco-friendly inorganic binders that do not produce harmful gas were synthesized. Then characteristic analyses were carried out with artificial sand and natural sand. Physical and chemical properties were compared using X-Ray Fluorescence (XRF), Powder Flow Test (PFT) and particle size distribution analyses. The general strength and absorption (absolute humidity 29.9 g/cm<sup>3</sup>) strength of the sample core was measured using each sand (artificial sand, natural sand) and inorganic binder. Also, X-ray Photoelectron Spectroscope (XPS) analysis confirmed the combination structure. As a result, it was confirmed that artificial sand exhibited mold characteristics with similar strength even with lower inorganic binder content than natural sand.

Identifying redox transition zones in the subsurface of a site with historical contamination

Reactive iron mineral coatings found throughout reduction-oxidation (redox) transition zones play an important role in contaminant transformation processes. This research focuses on demonstrating a process for effectively delineating redox transition zones at a site with historical contamination. An 18.3 meter core was collected, subsampled, and preserved under anoxic conditions to maintain its original redox status. To ensure a high vertical resolution, sampling increments of 5.08 cm in length were analyzed for elemental concentrations with X-ray fluorescence (XRF), sediment pH, sediment oxidation-reduction potential (ORP), total volatile organic carbon (TVOC) concentration in the sample headspace, and abundant bacteria (16S rRNA sequencing). Over the core's length, gradients observed ranged from 3.74 to 8.03 for sediment pH, −141.4 mV to +651.0 mV for sediment ORP, and from below detection to a maximum of 9.6 ppm TVOC concentration (as chlorobenzene) in the headspace. The Fe and S gradients correlated with the presence of Fe and S reducing bacteria. S concentrations peaked in the Upper Zone and Zone 1 where Desulfosporosinus was abundant, suggesting precipitation of iron sulfide minerals. In Zone 2, Fe concentrations decreased where Geobacter was abundant, potentially resulting in Fe reduction, dissolution, and precipitation of minerals with increased solubility compared to the Fe(III) minerals. Using complementary geochemical and microbial data, five redox transition zones were delineated in the core collected. This research demonstrates a systematic approach to characterizing redox transition zones in a contaminated environment.

Emission from Uyo Main Refuse Dumpsite and Potential Impact on Health

This paper presents potential impact on health of emission from landfill site on Uyo village road, Uyo local government area of Akwa Ibom State, Nigeria. Three sampling points were assessed for particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), sulphur dioxide (SO2), carbon monoxide (CO), hydrogen sulphide H2S, ammonia (NH3), total volatile organic carbon (TVOC) and hydrogen cyanide (HCN) using highly sensitive digital portable meters. The data obtained were expressed in terms of an air quality index. Air quality index indicates that the ambient air can be described as unhealthy for sensitive groups for NO2, unhealthy for SO2 and PM2.5 and moderate for CO, respectively. H2S, NH3, TVOC, HCN, PM10 were not indicated in USEPA air quality standards. It recommended that stringent and proper landfill emissions management together with appropriate burning of wastes should be considered in the study area to ease the risks associated with these pollutants on public health.

Estimation of atmospheric total organic carbon (TOC) – paving the path towards carbon budget closure

Abstract. The atmosphere contains a rich variety of reactive organic compounds, including gaseous volatile organic carbon (VOCs), carbonaceous aerosols, and other organic compounds at varying volatility. Here we present a novel and simple approach to measure atmospheric non-methane total organic carbon (TOC) based on catalytic oxidation of organics in bulk air to carbon dioxide. This method shows little sensitivity towards humidity and near 100 % oxidation efficiencies for all VOCs tested. We estimate a best-case hourly precision of 8 ppb C during times of low ambient variability in carbon dioxide, methane, and carbon monoxide (CO). As proof of concept of this approach, we show measurements of TOC+CO during August–September 2016 from a coastal city in the southwest United Kingdom. TOC+CO was substantially elevated during the day on weekdays (occasionally over 2 ppm C) as a result of local anthropogenic activity. On weekends and holidays, with a mean (standard error) of 102 (8) ppb C, TOC+CO was lower and showed much less diurnal variability. TOC+CO was significantly lower when winds were coming off the Atlantic Ocean than when winds were coming off land if we exclude the weekday daytime. By subtracting the estimated CO from TOC+CO, we constrain the mean (uncertainty) TOC in Atlantic-dominated air masses to be around 23 (±≥8) ppb C during this period. A proton-transfer-reaction mass spectrometer (PTR-MS) was deployed at the same time, detecting a large range of organic compounds (oxygenated VOCs, biogenic VOCs, aromatics, dimethyl sulfide). The total speciated VOCs from the PTR-MS, denoted here as Sum(VOC), amounted to a mean (uncertainty) of 12 (±≤3) ppb C in marine air. Possible contributions from a number of known organic compounds present in marine air that were not detected by the PTR-MS are assessed within the context of the TOC budget. Finally, we note that the use of a short, heated sample tube can improve the transmission of organics to the analyzer, while operating our system alternately with and without a particle filter should enable a better separation of semi-volatile and particulate organics from the VOCs within the TOC budget. Future concurrent measurements of TOC, CO, and a more comprehensive range of speciated VOCs would enable a better characterization and understanding of the atmospheric organic carbon budget.

Utilization of alternative fuels and materials in cement kiln towards emissions of benzene, toluene, ethyl-benzene and xylenes (BTEX)

Co-processing in cement industry has benefits for energy conservation and waste recycling. Nevertheless, emissions of benzene, toluene, ethyl-benzene, and xylenes (BTEX) tend to increase compared to a non co-processing kiln. A study was conducted in kiln feeding solid AFR (similar to municipal solid waste, MSW) having production capacity 4600-ton clinker/day (max. 5000 ton/day) and kiln feeding biomass having production capacity 7800-ton clinker/day (max. 8000 ton/day). The concentration of VOCs emissions tends to be higher at the raw mill on rather than the raw mill off. At the raw mill on, concentration of total volatile organic carbon (VOCs) emission from cement kiln stack feeding Solid AFR 1, biomass, Solid AFR 2, and mixture of Solid AFR and biomass is 16.18 mg/Nm3, 16.15 mg/Nm3, 9.02 mg/Nm3, and 14.11 mg/Nm3 respectively. The utilization of biomass resulted in the lower fraction of benzene and the higher fraction of xylenes in the total VOCs emission. Operating conditions such as thermal substitution rate, preheater temperature, and kiln speed are also likely to affect BTEX emissions.

Rapid total volatile organic carbon quantification from microbial fermentation using a platinum catalyst and proton transfer reaction-mass spectrometry.

A novel analytical system was developed to rapidly and accurately quantify total volatile organic compound (VOC) production from microbial reactor systems using a platinum catalyst and a sensitive CO2 detector. This system allows nearly instantaneous determination of total VOC production by utilizing a platinum catalyst to completely and quantitatively oxidize headspace VOCs to CO2 in coordination with a CO2 detector. Measurement of respiratory CO2 by bypassing the catalyst allowed the total VOC content to be determined from the difference in the two signals. To the best of our knowledge, this is the first instance of a platinum catalyst and CO2 detector being used to quantify the total VOCs produced by a complex bioreactor system. Continuous recording of these CO2 data provided a record of respiration and total VOC production throughout the experiments. Proton transfer reaction-mass spectrometry (PTR-MS) was used to identify and quantify major VOCs. The sum of the individual compounds measured by PTR-MS can be compared to the total VOCs quantified by the platinum catalyst to identify potential differences in detection, identification and calibration. PTR-MS measurements accounted on average for 94 % of the total VOC carbon detected by the platinum catalyst and CO2 detector. In a model system, a VOC producing endophytic fungus Nodulisporium isolate TI-13 was grown in a solid state reactor utilizing the agricultural byproduct beet pulp as a substrate. Temporal changes in production of major volatile compounds (ethanol, methanol, acetaldehyde, terpenes, and terpenoids) were quantified by PTR-MS and compared to the total VOC measurements taken with the platinum catalyst and CO2 detector. This analytical system provided fast, consistent data for evaluating VOC production in the nonhomogeneous solid state reactor system.Electronic supplementary materialThe online version of this article (doi:10.1186/s13568-016-0264-2) contains supplementary material, which is available to authorized users.

지상과 지하역사의 실내공기질 특성과 외기영향 평가

Abstract In this study, the air quality of underground and overground railway stations was evaluated focusing onthe degree of influence of the outside air quality. The measured components were particulate matter (PM 10 ), carbon dioxide (CO 2 ), carbon monoxide (CO), nitrogen dioxide (NO 2 ), formaldehyde (HCHO), ozone (O 3 ), total airborne bacteria (TAB), total volatile organic carbon (TVOC), and Radon (Rn), which are included in the maintenance standards and recommended standards of the Indoor Air Quality Management Act. Also, the indoor/outdoor concentration ratios of PM10, NO 2 , and O 3 were calculated to estimate the influence of the outdoor air quality. Theconcentrations of PM10 HCHO, TVOC, NO 2 , and Rn in the underground stations were found to be higher than thosein the overground stations. These results indicate that the (present) generation of contaminants are caused by the indoor source of the underground station. The ozone concentration of the overground stations was higher than thatof the underground stations, which indicates that the outdoor ozone concentration influenced that of the overgroundstations directly. Thus, methods of improving the IAQ should take into consideration the types of contamination

A novel field measurement method for determining fine particle and gas emissions from residential wood combustion

Emission data from residential wood combustion are usually obtained on test stands in the laboratory but these measurements do not correspond to the operational conditions in the field because of the technological boundary conditions (e.g. testing protocol, environmental and draught conditions). The field measurements take into account the habitual practice of the operators and provide the more reliable results needed for emission inventories. In this study, a workable and compact method for measuring emissions from residential wood combustion in winter conditions was developed. The emissions for fine particle, gaseous and PAH compounds as well as particle composition in real operational conditions were measured from seven different appliances. The measurement technique worked well and was evidently suitable for winter conditions. It was easy and fast to use, and no construction scaffold was needed. The dilution of the sample with the combination of a porous tube diluter and an ejector diluter was well suited to field measurement. The results indicate that the emissions of total volatile organic carbon (TVOC) (17 g kg −1 (of dry wood burned)), carbon monoxide (CO) (120 g kg −1) and fine particle mass (PM 1) (2.7 g kg −1) from the sauna stove were higher than in the other measured appliances. In the masonry heaters, baking oven and stove, the emissions were 2.9–9 g kg −1 TVOC, 28–68 g kg −1 CO and 0.6–1.6 g kg −1 PM 1. The emission of 12 PAHs (PAH 12) from the sauna stove was 164 mg kg −1 and consisted mainly of PAHs with four benzene rings in their structure. PAH 12 emission from other appliances was, on average, 21 mg kg −1 and was dominated by 2-ring PAHs. These results indicate that despite the non-optimal operational practices in the field, the emissions did not differ markedly from the laboratory measurements.

Approach for a novel control strategy for simultaneous nitrification/denitrification in activated sludge reactors

Biological nitrogen removal in activated sludge processes is conventionally obtained by a sequence of aerobic and anoxic processes. Kinetic mechanisms affecting the oxygen balance could trigger the production of total volatile organic carbon (TVOC) and nitric oxides (NO) under anoxic and anaerobic conditions. Measurements at a wastewater treatment pilot plant of capacity 1.6 m 3 wastewater show that the amount of TVOC and NO produced during the treatment process depends on carbon loading (low feed, balanced and overloaded) and aeration conditions. To confirm the results ORP, pH and dissolved oxygen (DO) are measured on-line and chemical parameters such as nitrate (NO 3-N), ammonium (NH 4-N) and TOC are measured in the wastewater. The ORP observed is in the range of −60 and +198 mV includes optimal setpoints for simultaneous nitrification and denitrification. From the pattern of NO emission plot, it can be assumed that a part of the produced NO 3-N is denitrified during the aeration period. NO emissions are especially high during denitrification conditions at low oxygen rates. The results suggest that both NO and TVOC emission concentrations in combination with ORP can be valuable parameters to control operation of a wastewater treatment plant. Continuous measurements of ORP and NO concentrations for estimation of NO emissions gauging the extent of nitrification or denitrification in the plant becomes possible.

Measurement of isoprene and its atmospheric oxidation products in a central Pennsylvania deciduous forest

Ambient concentrations of isoprene and several of its atmospheric oxidation productsmethacrolein, methylvinyl ketone, formaldehyde, formic acid, acetic acid, and pyruvic acid-were measured in a central Pennsylvania deciduous forest during the summer of 1988. Isoprene concentrations ranged from near zero at night to levels in excess of 30 ppbv during daylight hours. During fair weather periods, midday isoprene levels normally fell in the 5–10 ppbv range. Methacrolein and methylvinyl ketone levels ranged from less than 0.5 ppbv to greater than 3 ppbv with average midday concentrations in the 1 to 2 ppbv range. The diurnal behavior of formaldehyde paralleled that of isoprene with ambient concentrations lowest (∼1 ppbv) in the predawn hours and highest (>9.0 ppbv) during the afternoon. The organic acids peaked during the midday period with average ambient concentration of 2.5, 2.0, and 0.05 ppbv for formic, acetic, and pyruvic acid, respectively. These data indicate that oxygenated organics comprise a large fraction of the total volatile organic carbon containing species present in rural, forested regions of the eastern United States. Consequently, these compounds need to be included in photochemical models that attempt to simulate oxidant behavior and/or atmospheric acidity in these forested regions.