Reduction Of Volatile Organic Compounds Research Articles

Elucidating Contributions of Anthropogenic Volatile Organic Compounds and Particulate Matter to Ozone Trends over China.

In China, emissions of ozone (O3)-producing pollutants have been targeted for mitigation to reduce O3 pollution. However, the observed O3 decrease is slower than/opposite to expectations affecting the health of millions of people. For a better understanding of this failure and its connection with anthropogenic emissions, we quantify the summer O3 trends that would have occurred had the weather stayed constant by applying a numerical tool that "de-weathers" observations across 31 urban regions (123 cities and 392 sites) over 8 years. O3 trends are significant (p < 0.05) over 234 sites after de-weathering, contrary to the directly observed trends (only 39 significant due to high meteorology-induced variability). The de-weathered data allow categorizing cities in China into four different groups regarding O3 mitigation, with group 1 exhibiting steady O3 reductions, while group 4 showing significant (p < 0.05) O3 increases. Analysis of the relationships between de-weathered odd oxygen and nitrogen oxides illustrates how the changes in NOx, in anthropogenic volatile organic compounds (VOCs), and reductions in fine particulate matter (PM2.5) affect the O3 trends differently in these groups. While this analysis suggests that VOC reductions are the main driver of O3 decreases in group 1, groups 3 and 4 are primarily affected by decreasing PM2.5, which results in enhanced O3 formation. Our analysis demonstrates both the importance of and possibility for isolating emission-driven changes from climate and weather for interpreting short-term air quality observations.

Temporary reduction in VOCs associated with health risk during and after COVID-19 in Maharashtra, India.

A novel coronavirus has affected almost all countries and impacted the economy, environment, and social life. The short-term impact on the environment and human health needs attention to correlate the Volatile organic compounds (VOCs) and health assessment for pre-, during, and post lockdowns. Therefore, the current study demonstrates VOC changes and their effect on air quality during the lockdown. The findings of result, the levels of the mean for total VOC concentrations were found to be 15.45 ± 21.07, 2.48 ± 1.61, 19.25 ± 28.91 µg/m3 for all monitoring stations for pre-, during, and post lockdown periods. The highest value of TVOCs was observed at Thane, considered an industrial region (petroleum refinery), and the lowest at Bandra, which was considered a residential region, respectively. The VOC levels drastically decreased by 52%, 89%, 80%, and 97% for benzene, toluene, ethylbenzene, and m-xylene, respectively, during the lockdown period compared to the previous year. In the present study, the T/B ratio was found lower in the lockdown period as compared to the pre-lockdown period. This can be attributed to the complete closure of non-traffic sources such as industries and factories during the lockdown. The Lifetime Cancer Risk values for all monitoring stations for benzene for pre-and-post lockdown periods were higher than the prescribed value, except during the lockdown period. Supplementary InformationThe online version contains supplementary material available at 10.1007/s10874-022-09440-5.

Chemical characterization of volatile organic compounds (VOCs) emitted from multiple cooking cuisines and purification efficiency assessments

Cooking process can produce abundant volatile organic compounds (VOCs), which are harmful to environment and human health. Therefore, we conducted a comprehensive analysis in which VOCs emissions from multiple cuisines have been sampled based on the simulation and acquisition platform, involving concentration characteristics, ozone formation potential (OFP) and purification efficiency assessments. VOCs emissions varied from 1828.5 to 14,355.1 µg/m3, with the maximum and minimum values from Barbecue and Family cuisine, respectively. Alkanes and alcohol had higher contributions to VOCs from Sichuan and Hunan cuisine (64.1%), Family cuisine (66.3%), Shandong cuisine (69.1%) and Cantonese cuisine (69.8%), with the dominant VOCs species of ethanol, isobutane and n-butane. In comparison, alcohols (79.5%) were abundant for Huaiyang cuisine, while alkanes (19.7%), alkenes (35.9%) and haloalkanes (22.9%) accounted for higher proportions from Barbecue. Specially, carbon tetrachloride, n-hexylene and 1-butene were the most abundant VOCs species for Barbecue, ranging from 8.8% to 14.6%. The highest OFP occurred in Barbecue. The sensitive species of OFP for Huaiyang cuisine were alcohols, while other cuisines were alkenes. Purification efficiency assessments shed light on the removal differences of individual and synergistic control technologies. VOCs emissions exhibited a strong dependence on the photocatalytic oxidation, with the removal efficiencies of 29.0%–54.4%. However, the high voltage electrostatic, wet purification and mechanical separation techniques played a mediocre or even counterproductive role in the VOCs reduction, meanwhile collaborative control technologies could not significantly improve the removal efficiency. Our results identified more effective control technologies, which were conductive to alleviating air pollution from cooking emissions.

Phosphorus Modified Cardanol: A Greener Route to Reduce VolaTile Organic Compounds and Impart Flame Retardant Properties to Alkyd Resin Coatings.

Novel phosphorylated cardanol molecules based on phosphonate (PO3CR) and phosphate (PO4CR) functions were synthetized. Those molecules have two main actions which are described in this article: the reduction in volatile organic compounds (VOC) and the development of flame retardant (FR) properties conferred on alkyd resins used as coatings for wood specimen. Phosphorylated cardanol compounds have been successfully grafted by covalent bonds to alkyd resins thanks to an auto-oxidative reaction. The impact of the introduction of PO3CR and PO4CR on the film properties such as drying time and flexibility has been studied and the thermal and flame retardant properties through differential scanning calorimeter, thermogravimetric analysis and pyrolysis-combustion flow calorimeter. These studies underscored an increase in the thermal stability and FR properties of the alkyd resins. In the cone calorimeter test, the lowest pHRR was obtained with 3 wt% P of phosphate-cardanol and exhibited a value of 170 KW.m−2, which represented a decrease of almost 46% compared to the POxCR-free alkyd resins. Moreover, a difference in the mode of action between phosphonate and phosphate compounds has been highlighted. The most effective coating which combined excellent FR properties and good coating properties has been obtained with 2 wt% P of phosphate-cardanol. Indeed, the film properties were closed to the POxCR-free alkyd resin and the pHRR decreased by 41% compared to the reference alkyd resin.

축열식 연소산화장치 구현을 통한 VOCs 산화처리 및 폐열 회수 기술 개발

The reduction of greenhouse gases and Carbon Neutral (Carbon Zero) due to global warming is agreed by all countries around the world. The increase in global average temperature to climate change is kept within 2°C compared to before industrialization and achieved 1.5°C in the long run. Korea has set a 37% reduction target (315 million tons) compared to the 2030 emission forecast (851 million tons) and is promoting various air pollution reduction technologies and R&amp;D policies to reduce greenhouse gases and minimize the impact on climate change.&#x0D; Currently, there are VOCs that are directly emitted into the atmosphere or that cause greenhouse gases as simple power generation and heat sources. Aromatic hydrocarbons such as benzene are strong carcinogens that cause leukaemia, central nervous disorder, chromosomal abnormalities, and hydrochloride can produce photochemical oxides by destruction of the ozone layer, global warming, and chain reactions of volatile organic compounds, causing eye irritation, reduced visibility, and damage to plants and crops.&#x0D; VOCs reduction technology should reduce the amount of harmful substances in advance by controlling operating conditions and working conditions. Technologies that can effectively process VOCs throughput of 95% or more are heat storage combustion systems and heat storage catalyst combustion systems.&#x0D; This paper proposes a heat delivery system specification design and emission concentration measurement technology for high-efficiency waste heat recovery of 100 CMM RTO (Regenerative Thermal Oxidation) device to reduce air pollution in VOCs generating sites. For the application of the waste heat recovery system, a 100CMM heat storage combustion oxidation system (RTO) is designed, and the performance is evaluated by measuring the concentration of VOC (Volatile Organic Compound) emissions according to production process operating conditions.

Effects of combined carnosine and ultra-high pressure on the inhibition of fishy off-odor of snakehead fillets and the possible mechanism

The effects of combined application of ultra-high pressure (300 Mpa, 900 s) and carnosine on the inhibition of fishy off-odor from snakehead meat were investigated. Results showed that the combination effectively inhibited the formation of fishy volatile organic compounds (VOCs) and trimethylamine (TMA-N). Further studies demonstrated that the reduction of VOCs was mainly due to the inhibition of lipids oxidation based on the antioxidant activity of carnosine and the inactivation of lipoxygenase by UHP. Moreover, the reduction of TMA-N was mainly attributed to the ability of UHP processing to reduce bacterial load, which also extended the shelf-life of snakehead fillets by ∼ 6 days and retarded the production of TVB-N. Additionally, the combined application allowed a better retention of pH, color, and textural quality of the fillets compared with the control. Therefore, the current combination is a promising technique in fishy off-odor removing and better preservation of snakehead meat.

Grafting of Poly(ethylene imine) to Silica Nanoparticles for Odor Removal from Recycled Materials.

One of the major obstacles to the reuse of recycled plastic materials is the emanation of after-process odors from recycled polymers and composites. Typically, recycled polymers are blended with an off-odor adsorbent additive in the recycling chain to eliminate these smells. This article describes an innovative ultrasonically assisted method of grafting poly(ethylene imine) (PEI) to silica nanoparticles (SiO2) initiated by benzoyl peroxide (BP) which acts as an odor remover. To prepare the PEI/Si, the branched PEI was grafted onto the silica surface without a coupling agent. This made the grafting process straightforward, easy and low in cost. Fourier Transform Infrared (FTIR) analysis confirmed the successful grafting of PEI to silica. The thermogravimetric analysis (TGA) indicated the formation of two different fractions: a polymeric fraction covalently attached to the nanoparticle surface and a non-grafted PEI fraction that was removed during extraction. Up to 30% of the grafted-PEI fractions were produced at the lowest BP concentration with the highest PEI molecular weight at silica-to-PEI weight ratios of (1:1) to (3:1). The sensory assessment showed a substantial reduction in overall odor intensity for 30% of the recycled plastic-containing materials and a ~75% reduction in volatile organic compounds (VOCs) for 100% of the recycled plastics. These results strongly suggest that this innovative PEI/Si nanocomposite can be successfully commercialized for odor removal. To the authors’ best knowledge, this is the first reported work describing a one-pot reaction for grafting PEI to different nanoparticle surfaces.

Distribution and stable carbon isotopic composition of dicarboxylic acids, ketocarboxylic acids and &amp;lt;i&amp;gt;α&amp;lt;/i&amp;gt;-dicarbonyls in fresh and aged biomass burning aerosols

Abstract. Biomass burning (BB) is a significant source of dicarboxylic acids (diacids) and related compounds that play important roles in atmospheric chemistry and climate change. In this study, a combustion chamber and oxidation flow reactor were used to generate fresh and aged aerosols from burned rice, maize and wheat straw to investigate atmospheric aging and the stable carbon isotopic (δ13C) composition of these emissions. Succinic acid (C4) was the most abundant species in fresh samples, while oxalic acid (C2) became dominant after atmospheric aging. Of all diacids, C2 had the highest aged to fresh emission ratios (A/F), suggesting that C2 is largely produced through secondary photochemical processes. Compared with fresh samples, the emission factors of ketocarboxylic acids and α-dicarbonyls increased after 2 d but decreased after 7 d aging, indicating a short residence time and further atmospheric degradation from 2 to 7 d. The δ13C values of C2 for aged biomass samples were higher than those of urban aerosols but lower than marine or mountain aerosols, and the δ13C values of C2 became isotopically heavier during aging. Relationships between the reduction in volatile organic compounds (VOCs), such as toluene, benzene and isoprene, and increase in diacids after 2 d aging indicate that these VOCs led to the formation of diacids. However, no significant correlation was found between decreases in VOCs and increases in 7 d aged diacids. In addition, the A/F of C2 was 50.8 at 2 d and 64.5 at 7 d, indicating that the conversion of VOCs to C2 was almost completed within 2 d. For the longer aging times, the particulate-phase compounds may undergo further degradation in the oxidation processes.

A comparison of complexation induced brittleness in PEI/PSS and PEI/NaPSS single-step coatings

In the field of coatings, there is a major trend towards the reduction of volatile organic compounds by developing water-based alternatives for traditional solvent-based paints. Complexes of oppositely charged polyelectrolytes have recently emerged as a promising candidate for such coatings. Recently, we developed an ammonia-evaporation induced complexation approach to form polyelectrolyte complex films of two weak polyelectrolytes in a single step. Here, we extend this method by applying it to a combination of PEI/PSS, a weak polycation and a strong polyanion. Homogenous solutions at different ratios were successfully prepared. After casting and drying, dense and optically transparent layers were formed. As a comparison, PEI/NaPSS was also studied. Contrary to PEI/PSS, the pH in PEI/NaPSS films remains high during drying and NH3 evaporation, so PEI does not acquire a positive charge, thereby preventing complexation. We show that this leads to large differences in the properties of the films, with the PEI/NaPSS films being more sensitive to water, more ductile, and more prone to phase separation. We also found that the mechanical properties of the films depend strongly on the charge ratio: films made at a PEI/PSS ratio between 2:1 and 1:1 formed the strongest complexes, resulting in films that swell relatively little in water, but that are also brittle and prone to cracking during drying. In this work, we report a systematic study into this promising system and show its potential and tunability.

Quantitation study on VOC emissions and their reduction potential for coking industry in China: Based on in-situ measurements on treated and untreated plants

Currently, the characteristics of volatile organic compounds (VOC) released from coking industry are still vague, and the widely used VOC emission factors (EFs) were still from the measurements of 1990s. Hence, focusing on coking industry, we conducted an in-situ measurement campaign in several typical plants, developed a set of VOC EFs for various release units, and estimated the current emission amounts and future reduction potentials of VOC in China. The measurements show that the levels of VOC in stationary units were 63.82–9563.93 μg·m−3, and those surrounding fugitive units were 111.37–1436.36 μg·m−3. VOC emissions from stationary units were directly calculated, which deducing EFs of 11.57, 15.51, 127.13, 0.28, 0.16 g·t−1 coke respectively for coke charging, coke pushing, coke oven chimney, dry quenching, and wastewater treatment processes. Meanwhile, VOC emissions from fugitive units were simulated following the inverse dispersion method, which achieving EFs of 443.34 ± 66.31, 352.12 ± 65.81, and 718.56 ± 132.69 g·t−1 coke respectively for the coke oven leakage, byproduct recovery with VOC treatment system, and byproduct recovery without VOC treatment system. Generally, the coking plants installing VOC treatment system had total VOC EF of 953.76 g·t−1 coke, about 37.1% lower than those never considering VOC treatment (1516.25 g·t−1 coke). According to these developed EFs, the VOC emission amount from coking industry in China were estimated, slightly decreasing from 623.54 to 578.17 Gg per year, although the coke production increasing from 410.86 to 418.26 Tg during 2015–2019. In future, according to the national industrial policies, regulations and standards, technical guidelines, the VOC reduction potential of this industry in China could reach 336.9 Gg, to which headstream adjustment, process improvement, and end-of-pipe control contributed about 21.4%, 31.6%, and 47.0%, respectively.

Characteristics and Source Apportionment of Vehicular VOCs Emissions in a Tunnel Study

To explore the emission characteristics of volatile organic compounds (VOCs) from vehicular exhaust sources and evaporative sources with ethanol gasoline (E10) as the main fuel, VOCs sampling campaigns were carried out in the north third ring tunnel of Zhengzhou city for two consecutive weeks in December 2019. In addition, the characteristics of traffic flow and environmental information were also monitored in the tunnel. Firstly, 106 VOCs were quantified using gas chromatography/mass spectrometry (GC/MS), and then source apportionment of VOCs in the tunnel was carried out using a positive matrix factorization (PMF5.0)-chemical mass balance (CMB8.2) composite model. Finally, the ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAFP) of vehicle exhaust sources and evaporative sources were analyzed using the maximum incremental reactivity (MIR) and fractional aerosol coefficient (FAC). The results showed that ρ(VOCs) in the tunnel was (2794.5±147.4) μg·m-3 during the experiment, among which halogenated hydrocarbons[(32.4±2.0)%] accounted for the highest proportion, followed by aromatic hydrocarbons[(27.5±0.6)%] and alkanes[(23.3±0.8)%]. Source apportionment of vehicular VOCs showed that exhaust emissions (62.5%)>evaporative emissions (37.5%), whereas the contribution of OFP was that exhaust emissions (71.9%)>evaporative emissions (28.1%), and the contribution of SOAFP was that exhaust emissions (75.8%)>evaporative emissions (24.2%). The dominant components of OFP in evaporative sources were m,p-diethylbenzene, isoprene, and trans-2-pentene, whereas m,p-diethylbenzene, m,p-xylene, and 1,2,3-trimethylbenzene were the dominant components of SOAFP. The major components of OFP in exhaust sources were m,p-xylene, 1,2,4-trimethylbenzene, and 1,3,5-trimethylbenzene, whereas m,p-xylene, m,p-diethylbenzene, and 1,3,5-trimethylbenzene were the dominant components of SOAFP. In regions where ethanol gasoline is used, special attention should be paid not only to the exhaust emissions control but also to strengthening the emissions reduction of VOCs from vehicle evaporative sources, especially the high active components such as aromatic hydrocarbons and alkenes.

Seasonality and reduced nitric oxide titration dominated ozone increase during COVID-19 lockdown in eastern China

With improving PM2.5 air quality, the tropospheric ozone (O3) has become the top issue of China’s air pollution control. Here, we combine comprehensive observational data analysis with models to unveil the contributions of different processes and precursors to the change of O3 during COVID-19 lockdown in the Yangtze River Delta (YRD), one of the most urbanized megacity regions of eastern China. Despite a 44 to 47% reduction in volatile organic compounds (VOCs) and nitrogen oxides (NOx) emissions, maximum daily 8-h average (MDA8) ozone concentrations increase from 28 ppbv in pre-lockdown to 43 ppbv in lockdown period. We reproduce this transition with the WRF-Chem model, which shows that ~80% of the increase in MDA8 is due to meteorological factors (seasonal variation and radiation), and ~20% is due to emission reduction. We find that daytime photochemistry does not lead to an increase but rather a decrease of daytime O3 production during the lockdown. However, the reduced O3 production is overwhelmed by the weakened nitric oxide (NO) titration resulting in a net increase of O3 concentration. Although the emission reduction increases O3 concentration, it leads to a decrease in the Ox (O3 + NO2) concentration, suggesting reduced atmospheric oxidation capacity on a regional scale. The dominant effect of NO titration demonstrates the importance of prioritizing VOCs reduction, especially from solvent usage and the petrochemical industry with high emission ratios of VOCs/NOx.

Asphalt VOCs reduction of zeolite synthesized from solid wastes of red mud and steel slag

Asphalt material releases VOCs (Volatile Organic Compounds) during its paving and service periods. Therefore, it is an urgent need to conduct research on VOCs reduction in asphalt materials. This research reused red mud and steel slag to synthesize zeolite for asphalt VOCs reduction purpose. Two-step hydrothermal method was used and the optimized synthesis conditions were studied. The performance of asphalt VOCs reduction resulted from the optimized zeolite was also discussed. Research results indicated that zeolite Y with a specific surface area in 685 m2/g and pore volume in 0.07 cm3/g can be obtained by reusing red mud and steel slag. The pore size of the optimized zeolite is mainly concentrated between 2 and 6 nm. Moreover, addition of optimized zeolite significantly reduces the volume of asphalt VOCs by more than 45%. The incorporation of 5% zeolite performs best in adsorption experiments with the absorption capacity in 60%.

Adsorption and membrane separation for removal and recovery of volatile organic compounds

Volatile organic compounds (VOCs) are a crucial kind of pollutants in the environment due to their obvious features of severe toxicity, high volatility, and poor degradability. It is particularly urgent to control the emission of VOCs due to the persistent increase of concentration and the stringent regulations. In China, clear directions and requirements for reduction of VOCs have been given in the “national plan on environmental improvement for the 13th Five-Year Plan period”. Therefore, the development of efficient technologies for removal and recovery of VOCs is of great significance. Recovery technologies are favored by researchers due to their advantages in both recycling VOCs and reducing carbon emissions. Among them, adsorption and membrane separation processes have been extensively studied due to their remarkable industrial prospects. This overview was to provide an up-to-date progress of adsorption and membrane separation for removal and recovery of VOCs. Firstly, adsorption and membrane separation were found to be the research hotspots through bibliometric analysis. Then, a comprehensive understanding of their mechanisms, factors, and current application statuses was discussed. Finally, the challenges and perspectives in this emerging field were briefly highlighted.

Potential of a year-round, closed-loop process for volatile organic compounds reduction in pinewood strands by Pseudomonas putida PX1 cultivated in seasonally varying process effluents

Sustainable utilization of waste streams from bioresources is a challenging opportunity for the future. This study investigated the potential of a seasonally varying process effluent stream from medium-density fiberboard production for a year-round cultivation process of Pseudomonas putida PX1 for reduction of volatile organic compounds (VOC) in pinewood strands. For four years, seasonal variations with abundant fermentable carbon sources during colder periods and few carbon sources during warmer periods were observed. Nitrogen sources present in process effluent required for optimal biomass production are insufficient when abundant carbon sources are available and should be supplemented. VOC reduction in pinewood strands with P. putida after mixed substrate fermentation showed very promising results for industrial applications. Total VOC emissions were reduced by more than 55% in only 3 h. Most aldehydes and terpenes were effectively reduced by 67%–100%, except for Δ-3-carene and α-terpinolene, which were reduced by 20%–22%.

The impacts of VOCs on PM2.5 increasing via their chemical losses estimates: A case study in a typical industrial city of China

Volatile organic compounds (VOCs) have been explicitly required to be controlled by national or local governments to tackle heavy PM2.5 pollution in China. However, the role of VOCs chemistry in PM2.5 is still far away from being fully understood. In this study, we selected a typically industrialized city of China, conducted VOCs online measurements in July and December of 2020, estimated VOCs chemical losses, and explored their impacts on PM2.5 in the real atmosphere. Our measurements totally detected the mixing ratios of 53 VOCs species, sum of which reaching 20.8 ± 9.1 ppb and 45.5 ± 19.8 ppb in July and December respectively. Based on the change in the relative abundance of various VOCs species with different reactivity, daily OH exposure and daily O3 exposure (molecules·s·cm−3) were estimated, respectively with the mean value of 11.0 × 1010 and 5.2 × 1015 in July, 5.9 × 1010 and 3.1 × 1015 in December. Thus, there were about 6.7 ± 3.2 ppb and 11.1 ± 5.0 ppb VOCs chemically lost in July and December, with the average loss ratio of 29.7% and 19.3% in respective. In July, PM2.5 in the range of 20–60 μg m−3 positively responded to VOCs loss ratios, and high PM2.5 values were always accompanied by higher VOCs losses instead of high CO levels; but their relationship became negative in December when PM2.5 in the range of 40–150 μg m−3, and extremely high PM2.5 values happened in high CO conditions instead of high VOCs losses conditions. Moreover, PM2.5 measurements in this city also showed an apparent upward trend in OC/EC with PM2.5 in summer, but a slight downward trend in winter. These all indicated that in the conditions of stronger solar radiations (summer) and low-middle aerosol loads, VOCs chemistry played the important role in PM2.5 increasing through contributing SOA; but in the conditions of lower solar radiations (winter) and heavy aerosol loads, VOCs chemistry was greatly weakened and had the minor impact on PM2.5 increasing. The measure involving VOCs reduction to alleviate PM2.5 pollution in winter needs to be cautiously considered and examined.

Evaluation of the VOC pollution pattern and emission characteristics during the Beijing resurgence of COVID-19 in summer 2020 based on the measurement of PTR-ToF-MS

A second wave of coronavirus disease 2019 (COVID-19) infections emerged in Beijing in summer 2020, which provided an opportunity to explore the response of air pollution to reduced human activity. Proton-transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) coupled with positive matrix factorization (PMF) source apportionment were applied to evaluate the pollution pattern and capture the detailed dynamic emission characteristics of volatile organic compounds (VOCs) during the representative period, with the occurrence of O3 pollution episodes and the Beijing resurgence of COVID-19. The level of anthropogenic VOC was lower than during the same period in previous years due to the pandemic and emission reduction measures. More than two thirds of the days during the observation period were identified as high-O3 days and VOCs exhibited higher mixing ratios and faster consumption rates in the daytime on high-O3 days. The identified VOC emission sources and the corresponding contributions during the whole observation period included: vehicle + fuel (12.41 ± 9.43%), industrial process (9.40 ± 8.65%), solvent usage (19.58 ± 13.46%), biogenic (6.03 ± 5.40%), background + long-lived (5.62 ± 11.37%), and two groups of oxygenated VOC (OVOC) factors (primary emission and secondary formation, 26.14 ± 15.20% and 20.84 ± 14.0%, respectively). Refined dynamic source apportionment results show that the ‘stay at home’ tendency led to decreased emission (−34.47 ± 1.90%) and a weakened morning peak of vehicle + fuel during the Beijing resurgence. However, a growing emission of primary OVOCs (+51.10 ± 8.28%) with similar diurnal variation was observed in the new outbreak and afterwards, which might be related to the enhanced usage of products intended to clean and disinfect. The present study illustrated that more stringent VOC reduction measures towards pandemic products should be carried out to achieve the balanced emission abatement of NO x and VOC when adhering to regular epidemic prevention and control measures.

Impact of Air-Purifying Plants on the Reduction of Volatile Organic Compounds in the Indoor Hot Desert Climate

Due to hot desert weather, residents of the United Arab Emirates (UAE) spend 90% of their time indoors, and the interior environment of the newly built apartments with inappropriate material and ventilation is causing sick building syndrome (SBS), faster than in any other country. NASA studies on indoor air pollutants indicate that the usage of 15–18 air-purifying plants in 18–24 cm diameter containers can clean the air in an average 167.2 m2 house (approximately one plant per 9.2 m2). This study investigates the effect of three different types of air-purifying plants, Pachira aquatica, Ficus benjamina, and Aglaonema commutatum, in reducing volatile organic compounds (VOCs) and formaldehyde (CH2O) in hot desert climate. An experiment is performed in which the CH2O and VOCs concentrations are measured in two laboratory spaces (Room 1 and Room 2). Different volumes (5 and 10% of the laboratory volume) of target plants are installed in Room 1, whereas Room 2 is measured under the same conditions without plants for comparison. The results show that the greater the planting volume (10%), the greater is the reduction effect of each VOCs. In summer in hot desert climate, the initial concentration (800 µg/cm3) of CH2O and VOCs is higher, and the reduction amount is higher (534.5 µg/cm3) as well. The reduction amount of CH2O and toluene (C7H8) is particularly high. In the case of C7H8, the reduction amount (45.9 µg/cm3) is higher in summer with Aglaonema commutatum and Ficus benjamina. It is statistically proven that Ficus benjamina is most effective in reducing CH2O and C7H8 in an indoor space in hot desert climate. The findings of this study can serve as basic data for further improving the indoor air quality using only air-purifying plants in hot desert climate of the United Arab Emirates.

Reduction of Volatile Organic Compounds by Implementing Best Engineering Practices at Chemical Analysis Laboratory

Reduction of Volatile Organic Compounds by Implementing Best Engineering Practices at Chemical Analysis Laboratory

Controlled Air Exchange Rate Method to Evaluate Reduction of Volatile Organic Compounds by Indoor Air Cleaners

Controlled Air Exchange Rate Method to Evaluate Reduction of Volatile Organic Compounds by Indoor Air Cleaners