Reduction Of Volatile Organic Compounds Research Articles

Characteristics and sources of VOCs in urban and suburban environments in Shanghai, China, during the 2016 G20 summit

To improve air quality for the period of the G20 Hangzhou Summit, comprehensive and stringent emission controls were implemented over the Yangtze River delta region, China. To evaluate the impacts of emission controls on variations of atmospheric volatile organic compounds (VOCs), field measurements of VOCs were conducted at urban and suburban sites in Shanghai from August 24 to September 15, 2016. At both sites, the total budgets of VOCs were determined by alkanes (48.05–57.62%), followed by alkenes (4.74–10.17%), acetylene (0.16–3.90%), and aromatics (32.16–45.64%). As indicated by maximum incremental reactivity methods, aromatics were likely the most important VOCs groups for the ozone formation potential. All of VOCs presented to have significant increases, the maximum rate of change 74.47% at PD and 147.92% at DSL, after the G20 summit were compared with the G20 summit, suggesting the substantial reduction in VOCs due to emission controls over regional scales. Positive matrix factorization analysis of VOCs identified five sources, including petrochemical industry, vehicle exhaust, LPG/NG/fuel vaporization (for suburban the source appended incomplete combustion), solvent usage, organic synthetic materials (only for urban) and plant sources were (only for suburban), at the two sites, respectively. On average, petrochemical industry was the largest contributor (22.11–33.89%) to the total VOCs, followed by vehicle exhaust (22.22–27.27%) and solvent usage (15.01–20.11%). High loadings of VOCs were observed associating with westerly and northerly wind, reflecting the impact of regional transport from surrounding regions on VOCs pollution in Shanghai.

Biochar reduces volatile organic compounds generated during chicken manure composting

The efficiency of biochar for reducing the levels of volatile organic compounds (VOC) was investigated in a composting mixture containing 90% poultry manure and 10% straw (with and without 3% biochar addition) at three different stages of the process. The use of a low application rate of biochar reduced the concentration of VOC during the thermophilic phase. Biochar significantly reduced the levels of nitrogen volatile compounds, which are the most abundant VOC family, originated from microbial transformation of the N-compounds originally present in manure. The most efficient VOC reduction was observed in oxygenated volatile compounds (ketones, phenols and organic acids), which are intermediates of organic matter degradation, whereas there was no effect on other VOC families (aliphatic, aromatic and terpenes). These results suggest the importance of not only the sorption capacity of biochar but also its impact in the composting progress as main drivers for VOC reduction.

Reductions in Volatile Organic Compound Emissions from Coal-Fired Power Plants by Combining Air Pollution Control Devices and Modified Fly Ash

The distributions and reductions of volatile organic compounds (VOCs; alkanes, aromatics, and halogenated hydrocarbons) emitted from two coal-fired power plants were compared. The partial removal of VOCs by air pollution control devices meant to reduce NOx, particulate matter, and SOx was assessed. The data show that VOC levels in flue gas were reduced by 5–35% after selective catalytic reduction, 0–40% after air preheating and electrostatic precipitation, and 10–20% after flue gas desulfurization and wet electrostatic precipitation. Adding modified fly ash was found to further reduce the effluent concentration of VOCs by 10–20%, resulting in an overall VOC reduction of 40–80%. This decrease in emissions is attributed to oxidation, deposition, condensation, and water absorption mechanisms.

Responses of PM2.5 and O3 concentrations to changes of meteorology and emissions in China

Tremendous efforts have been made to reduce the severe air pollution in China since 2013. However, the annual and peak fine particulate matter (PM2.5) concentrations during severe events in winter did not always reduce as expected. This is partially due to the inter-annual variation of meteorology, which affects the emission, transport, transformation, and deposition processes of air pollutants. In this study, the responses of PM2.5 and ozone (O3) concentrations to changes in emission and meteorology from 2013 to 2015 were investigated based on ambient measurements and the Community Multi-Scale Air Quality (CMAQ) model simulations with anthropogenic emissions. It is found that emission reductions in 2014 and 2015 effectively reduced PM2.5 concentrations by 23.9 and 43.5 μg/m3, respectively, but was partially counteracted by unfavorable meteorology. The negative effects from unfavorable meteorology were significant in extreme pollution events. For example, in December 2015, unfavorable meteorology caused a great increase (90 μg/m3) of PM2.5 in Beijing. Reduction of primary PM and gaseous precursors led to 13.4 and 16.5 ppb increase of O3-8 h daily concentrations in the summertime in 2014 and 2015 in comparison of 2013, which was likely caused by the increase of solar actinic flux due to PM reduction. In addition, reduction of nitrogen oxides (NOx) emissions in areas with negative NOx-O3 sensitivity could lead to an increase of O3 formation when the reduction of volatile organic compounds (VOCs) was not sufficient. This unintended enhanced O3 formation could also lead to higher O3 in downwind areas. This study emphasizes the role of meteorology in pollution control, validates the effectiveness of PM2.5 control measures in China, and highlights the importance of appropriate joint reduction of NOx and VOCs to simultaneously decrease O3 and PM2.5 for higher air quality.

The human health risk estimation of inhaled oil spill emissions with and without adding dispersant

Airborne toxic compounds emitted from polluted seawater polluted after an oil spill raise health concerns when inhaled by humans or other species. Inhalation of these toxic compounds as volatile organic compounds (VOCs) or airborne fine particulate matter (PM) may cause serious pulmonary diseases, including lung cancer. Spraying chemical dispersants to enhance distribution of the crude oil into the water was employed extensively during the Deepwater Horizon spill. There is some evidence that dispersion of the crude oil decreased the emission rate of the VOCs but increased the emission rates of fine PM that may carry toxic compounds. In this study, the cancer risks and non-cancer hazards of the detected VOCs and particulates for spill-response workers were estimated with and without use of dispersant under action of breaking waves. A subchronic exposure scenario was modeled to address the inhalation health threat during initial phases of an oil spill response. A dosimetry model was used to estimate regional deposition of PM. Use of dispersant reduced benzene cancer risks from 57 to 37 excess lifetime cancer cases per million for 1 h of daily exposure that continues for 3 months. Adding dispersant resulted in emissions reductions of the lighter VOCs (up to 30% lower). However, hazard quotients (HQs) of the non-carcinogenic VOCs even after dispersant addition were above 1 meaning there are serious concerns about exposure to these VOCs. Inhalation of airborne particles emitted from the slick containing dispersant increased the total mass of deposited particles in upper respiratory regions compared to the slick of crude oil only. This study showed the application of dispersant onto the pollution slick increased the total mass burden to the human respiratory system about 10 times, an exploratory HQ analysis is presented to evaluate the potential health risk.

Potential role of fecal volatile organic compounds as biomarkers of chemically induced intestinal inflammation in mice.

Metabolomics studies have the potential to discover biomarkers. Fecal volatile organic compounds (VOCs) have been found to differ in patients with inflammatory bowel disease and irritable bowel syndrome. Murine models of colitis offer an alternative to human studies in which diet can be controlled. We aimed to investigate fecal VOCs from mice in which acute and chronic colitis was induced. Groups of adult C57BL/6 mice underwent treatment with oral dextran sulfate sodium to induce colitis. Control mice received no treatment or had acute osmotic diarrhea induced with magnesium sulfate. Colitis was assessed clinically and by histology. Samples of feces and/or colon contents were collected and volatile compounds determined by solid phase microextraction-GC-MS. Statistics were performed using metabolomics tools. Acute colitis was associated with an increase in aldehydes and chronic colitis with one specific ketone. Osmotic diarrhea was associated with a significant reduction in VOCs, especially alcohols. We provide evidence that the identification of disease-associated VOC concentration ranges, combined with specific marker compounds, would potentially increase the likelihood of finding an inflammatory bowel disease-specific fecal VOC marker profile.-Reade, S., Williams, J. M., Aggio, R., Duckworth, C. A., Mahalhal, A., Hough, R., Pritchard, D. M., Probert, C. S., Potential role of fecal volatile organic compounds as biomarkers of chemically induced intestinal inflammation in mice.

The Spatiotemporal Response of Summertime Tropospheric Ozone to Changes in Local Precursor Emissions in the Lower Fraser Valley, British Columbia

ABSTRACTThis paper examines the spatiotemporal impact of changing local precursor emissions on a subset of air quality monitors in the coastal Lower Fraser Valley, British Columbia, Canada, over a 25-year period (1990–2014) marked by substantial emissions reductions. The analysis examines summertime (JJA) trends in ambient reactivity of volatile organic compounds (VOCs), , ozone, and odd oxygen (; defined as ) concentrations. To account for the potentially confounding influence of rising background ozone levels on the analysis, summer days are classified by whether appreciable local ozone production is likely or not, with a separate analysis undertaken for each set of conditions. The influence of short- and long-term meteorological variability, hebdomadal (weekly) emissions variability, and within-network spatial variability on long-term trends is accounted for by using Generalized Additive Models (GAM). The analysis suggests that long-term trends in local ambient VOC reactivity and concentrations have not occurred in a uniform fashion nor have they changed in a synchronized way. Declines in VOC reactivity appear to have occurred sooner and at a more uniform rate, but concentrations appear to have remained constant for the first 10 years before rapidly declining. Similarly, we find ozone reductions have not occurred uniformly in time nor has the network response been spatially uniform, with the smallest reductions occurring just downwind of the region's downtown core and the largest reductions about 40 km further downwind. Much of the non-uniformity in response can be attributed to changing odd-oxygen partitioning rather than changing ozone production. During our analysis period, ozone concentrations during days not conducive to ozone photochemistry appear to have increased at a rate consistent with previous background trend analyses over western North America. We use the difference between ozone concentrations on fair-weather summer days and days with little photochemistry to build a response surface for “net-produced” ozone as a function of meteorologically controlled ambient VOC reactivity and concentrations. We find that much of the predicted behaviour in local ambient ozone can be understood in light of VOC-limited conditions and differing rates of local VOC and emissions reductions. It appears that these precursor reductions have largely resulted from evolving light-duty emission control technologies and local fleet turnover.

Volatile organic compounds at a rural site in Beijing: influence of temporary emission control and wintertime heating

Abstract. While residential coal/biomass burning might be a major and underappreciated emission source for PM2.5, especially during winter, it is not well constrained whether burning solid fuels contributes substantially to ambient volatile organic compounds (VOCs), which are precursors to secondary organic aerosols (SOAs) that typically have a higher contribution to particulate matter during winter haze events. In this study, ambient air samples were collected in 2014 from 25 October to 31 December at a rural site on the campus of the University of Chinese Academy of Sciences (UCAS) in northeastern Beijing for the analysis of VOCs. Since temporary intervention measures were implemented on 3–12 November to improve the air quality for the Asian-Pacific Economic Cooperation (APEC) summit held on 5–11 November in Beijing, and wintertime central heating started on 15 November in Beijing after the APEC summit, this sample collection period provided a good opportunity to study the influence of temporary control measures and wintertime heating on ambient VOCs. As a result of the temporary intervention measures implemented during 3–12 November (period II), the total mixing ratios of non-methane hydrocarbons averaged 11.25 ppb, approximately 50 % lower than the values of 23.41 ppb in period I (25 October–2 November) and 21.71 ppb in period III (13 November–31 December). The ozone and SOA formation potentials decreased by ∼50 % and ∼70 %, respectively, during period II relative to period I, with the larger decrease in SOA formation potentials attributed to more effective control over aromatic hydrocarbons mainly from solvent use. Back trajectory analysis revealed that the average mixing ratios of VOCs in southerly air masses were 2.3, 2.3 and 2.9 times those in northerly air masses during periods I, II and III, respectively; all VOC episodes occurred under the influence of southerly winds, suggesting much stronger emissions in the southern urbanized regions than in the northern rural areas. Based on a positive matrix factorization (PMF) receptor model, the altered contributions from traffic emissions and solvent use could explain 47.9 % and 37.6 % of the reduction in ambient VOCs, respectively, during period II relative to period I, indicating that the temporary control measures on vehicle emissions and solvent use were effective at lowering the ambient levels of VOCs. Coal/biomass burning, gasoline exhaust and industrial emissions were among the major sources, and they altogether contributed 60.3 %, 78.6 % and 78.7 % of the VOCs during periods I, II and III, respectively. Coal/biomass burning, mostly residential coal burning, became the dominant source, accounting for 45.1 % of the VOCs during the wintertime heating period, with a specifically lower average contribution percentage in southerly air masses (38.2 %) than in northerly air masses (48.8 %). The results suggest that emission control in the industry and traffic sectors is more effective in lowering ambient reactive VOCs in non-heating seasons; however, during the winter heating season reducing emissions from residential burning of solid fuels would be of greater importance and would have health co-benefits from lowering both indoor and outdoor air pollution.

Diurnal Variation of SOA Formation Potential from Ambient Air at an Urban Site in Beijing

Secondary organic aerosol (SOA) is an important component of atmospheric fine particles (PM2.5). The study of the diurnal variation of SOA formation potential is important for understanding the evolution of SOA and its contribution to fine particle pollution. The oxidation flow reactor (OFR) was used to study the SOA formation potential of ambient air in summer at an urban site in Beijing. The high concentration of OH radicals in the reactor can oxidize the volatile organic compounds (VOCs) and lead to SOA formation. The hour average SOA formation potential varied between 3.9-9.4 μg·m-3 in a day and had a higher value at night than in the daytime. The lowest value of SOA formation potential was about 3.9 μg·m-3 observed at 16:00 in the afternoon. This variation of SOA formation potential is consistent with the typical VOCs, such as toluene, and inversely related to the concentration of ozone. In addition to the impact of change in the height of the boundary layer, experimental data showed that the reduction of VOCs in photo-oxidation in the daytime was an important reason for the decrease of SOA formation potential in daytime. Compared to similar studies in developed countries, the SOA formation potential was higher in Beijing due to the higher concentrations of VOCs and might make an important contribution to the fine particle pollution in Beijing.

VOCs reduction and inhibition mechanisms of using active carbon filler in bituminous materials

Abstract Volatile organic compounds (VOCs), which are harmful to atmospheric environment and human health, will volatilize from bituminous binder in the process of production, transportation and construction. Many inhibitors were applied to reduce the VOCs emissions for designing environment friendly bituminous material. This paper investigated the possibility of using active carbon filler to reduce the VOCs emissions from bituminous materials, by means of thermogravimetry coupled with mass spectrometry (TG-MS). Eight types of emissions were studied through ion mass spectra. The influence of active carbon on VOCs was researched by ionic density and residual volatile speed. Storage stability of modified bituminous binder had been examined as well to ensure acceptable application purpose. For further consideration, the basic properties of active carbon characterized by Scanning Electron Microscope (SEM), Surface Area and Porosity Analyzer and Fourier Transform Infrared Spectroscopy (FT-IR), for better understanding of the inhibition mechanisms. Results illustrated that adding active carbon filler into bitumen would not degrade the storage stability. Active carbon filler with porous structure can significantly reduce the VOCs emissions. The inhibition effect depends on the kind of emissions and the inhibitor's adding ratio. The influence of active carbon on VOCs reduction increased with the addition ratio and the optimum adding quantity is 5 wt%, without significant reduction of road performance. High specific surface area and developed pore structure contributed to the physical adsorption between active carbon and VOCs molecules, while organic functional groups determined the selective chemical absorption of active carbon.

Toluene concentrations reduction by using photocatalytic coating methods for cementitious materials

Volatile organic compounds (VOC) generated from various sources like car combustion is one of the most surrounding pollutants, which can be transferred from one form to another in the presence of sunlight. In the present work the ability of the reduction of VOC have been conducted on cementitious samples surfaces by using toluene as a pollutant gas and TiO2 as an environmentally friendly photocatalyst . Two coating methods have been used (dip and spray) with two types of aqueous solution, prepared by spreading 3g/L micro and nano TiO2 powder with deionized water. A laboratory test procedure was adopted to assess the performance of the coated specimens. The specimens were subjected to toluene gas and there efficiency in gas removal was monitored with time. Furthermore, contact angle for the coated samples was also examined to investigate the hydrophilicity of the coated substrate. The results showed that TiO2 give high activity and work as a good photocatalyst for mitigation of air pollutants, and that it could be used in different ways and concentrations to obtain better air quality and aesthetic building appearance. The observed coating efficiency in reducing the toluene was more pronounced in higher than lower gas concentrations for the micro coated samples with removal efficiency equals to 13% and 10% for dipping and spraying method, respectively. While the higher removal was about 20% for both nano dipping and nanospray methods for the inlet gas concentration 3ppm. This behavior reflects the beneficial effects of TiO2 coating procedure in highly pollutant environments, like Iraq.

Allowance and allocation of industrial volatile organic compounds emission in China for year 2020 and 2030

As an effective pollution control method, emission allowance and allocation just implemented in volatile organic compounds (VOCs) control strategy of China in 2016. This article presents a possible way to set the emission allowance targets and establishes an allowance allocation model for the object year, 2020 and 2030, using 2010 as the reference year. On the basis of regression and scenario analysis method, the emission allowance targets were designed, which were 17.902Tg and 18.224Tg for 2020 and 2030, with an increasing rate of 28.75% and 31.06% compared to 2010. From the perspective of industries, processes using VOCs-containing products, like machinery and equipment manufacturing, would continue to be the most significant industrial VOCs emission sources in the future of China. Four allocation indicators were selected, which are per capita GDP of each province, per capita industrial VOCs emission of each province, the economic contribution of industrial sector to regional economy of each province, and the emission intensity per land area of each province, respectively. Based on information entropy, the weights of the indicators were calculated and an emission allocation model was established, and the results showed that provinces like Shandong, Jiangsu, Guangdong, Zhejiang and Fujian were calculated to obtain more emission allowance while burden more reduction responsibility. Meanwhile, provinces like Guizhou, Ningxia, Hainan, Qinghai and Xizang were on the contrary. This paper suggests governments to enhance or ease to industrial VOCs reduction burden of each province in order to stimulate its economy or change its way of economy development.

A comprehensive classification method for VOC emission sources to tackle air pollution based on VOC species reactivity and emission amounts

In China, volatile organic compound (VOC) control directives have been continuously released and implemented for important sources and regions to tackle air pollution. The corresponding control requirements were based on VOC emission amounts (EA), but never considered the significant differentiation of VOC species in terms of atmospheric chemical reactivity. This will adversely influence the effect of VOC reduction on air quality improvement. Therefore, this study attempted to develop a comprehensive classification method for typical VOC sources in the Beijing–Tianjin–Hebei region (BTH), by combining the VOC emission amounts with the chemical reactivities of VOC species. Firstly, we obtained the VOC chemical profiles by measuring 5 key sources in the BTH region and referencing another 10 key sources, and estimated the ozone formation potential (OFP) per ton VOC emission for these sources by using the maximum incremental reactivity (MIR) index as the characteristic of source reactivity (SR). Then, we applied the data normalization method to respectively convert EA and SR to normalized EA (NEA) and normalized SR (NSR) for various sources in the BTH region. Finally, the control index (CI) was calculated, and these sources were further classified into four grades based on the normalized CI (NCI). The study results showed that in the BTH region, furniture coating, automobile coating, and road vehicles are characterized by high NCI and need to be given more attention; however, the petro-chemical industry, which was designated as an important control source by air quality managers, has a lower NCI.

Fabrication of Polyurethane/Rare Earth Nanofiber Composite by Electrospinning and Its VOCs Reduction Characteristics

Volatile organic compounds (VOCs) are a source of air pollution and are harmful to both human health and the environment. In this study, we fabricated polyurethane/rare earth (PU/RE) composite nanofibrous membranes via electrospinning with the aim of removing VOCs from air. The morphological structure of PU/RE nanofibrous mats were investigated using FE-SEM, EDX, and XRD experimental analyses. A certain amount of RE (up to 50 wt% compared to PU pellets) particles could be loaded on/into PU fibers. The PU nanofiber containing 50 wt% RE powder had the smallest fiber diameter of 356 nm; it also showed the highest VOCs absorption capacity compared with other composite membranes, having an absorption capacity about 3 times greater than pure PU nanofibers. In addition, all of the PU/RE nanofibrous membranes readily absorbed styrene the most, followed by xylene, toluene, benzene and chloroform. Therefore, the PU/RE nanofibrous membrane can play an important role in removing VOCs from the air, and its development prospects are impressive because they are emerging materials.

Using Activated Carbon to Reduce the Volatile Organic Compounds from Bituminous Materials

AbstractThe objective of this research is to characterize the reduction of volatile organic compounds (VOCs) from bituminous materials resulted from activated carbon. A gas chromatography-mass spec...

Evaluating the effectiveness of joint emission control policies on the reduction of ambient VOCs: Implications from observation during the 2014 APEC summit in suburban Beijing

Ambient volatile organic compounds (VOCs) at a suburban Beijing site were on-line detected using proton transfer reaction-mass spectrometry (PTR-MS) during autumn of 2014, near the location of the Asia-Pacific Economic Cooperation (APEC) summit. During the APEC summit, the Chinese government enacted strict emission control policies. It was found that VOC concentrations only slightly decreased during the first emission control period (EC I), when control policies were performed in Beijing and 5 cities along the Tai-hang Mountains. However, most of the VOCs (10 out of 12 non-biogenic species) significantly decreased (more than 40%) during the second emission control period (EC II), when control policies were carried out in 16 cities including Beijing, Tianjin, 8 cities of Hebei province and 6 cities of Shandong province. Also the ratio of toluene and benzene decreased during EC II, likely because the emission control policies changed the proportions of different anthropogenic sources. Using the positive matrix factorization (PMF) source apportionment method, five factors are analyzed: (1) vehicle + fuel, (2) solvent, (3) biomass burning, (4) secondary, and (5) background + long-lived. Among them, vehicle + fuel, solvent and biomass burning contribute most of the VOCs concentrations (60%–80%) during the polluted periods and are affected most by emission control policies. During EC II, the reductions of vehicle + fuel, solvent, biomass burning and secondary species were all no less than 50%. Overall, when emission control policies were carried out in many North China Plain (NCP) cities (i.e. EC II), the VOC concentrations of suburban Beijing markedly decreased. This indicates the cross-regional joint-control policies have a large influence on reductions of organic gas species. The findings of this study have vital implications for helping formulate effective emission control policies in China and other countries.

Development of a novel Volumetric Matrix Dump Combustor for VOC reduction

VOCs (Volatile Organic Compounds) are produced mainly at work places or laundries using painting processes or organic solvents. These are composed of hydrocarbon of diversified forms and low calories due to the low concentration as they are released to atmosphere as to be diluted, making difficult direct burning by a conventional burner.In the present study, a new form of VMDC (Volumetric Matrix Dump Combustor) has been proposed to process such a low-calorie gas of VOC. This combustor is configured in the form of combining characteristics of a plasma burner, a dump combustor and a volumetric matrix burner. Hence, the VMDC is configured as a structure capable of securing sufficient decomposition temperature and residence time required for stable flame formation and VOC decomposition.To investigate performance and operation characteristics of the VMDC, experiments were conducted as parameters of gas feed rate, toluene concentration, VOC injection position, plasma input power, and heat recuperator by using toluene as a representative VOC.With the plasma burner, shortening of ignition time upon initial starting, enhancement in flame stability and combustibility, and expansion of flammable range were enabled, while not only high-efficiency decomposition but also processing of large amounts of VOC was possible by formation of a recirculation region in the dump combustor. And low-temperature, super-adiabatic, complete combustion and decomposition of VOC was made possible by the volumetric matrix burner.The optimum operation condition for VMDC involves the case where VOC with a toluene concentration of 3000ppm was supplied at 450L/min, where the VOC decomposition efficiency was 89.6%, and the specific input energy 333.3J/L, showing excellent performance as compared with the existing waste gas incinerators.

Improvement of Efficiency and Emissions from Wood Log Stoves by Retrofit Solutions

AbstractBiomass combustion systems contribute to the use of renewables, whereby wood log stoves have a high share for domestic heating. Promotion of renewables and efforts for lower air pollution require an improvement of technology. Short‐term effects can be achieved with the help of various retrofit systems. Apart from a survey of available systems, two measurements have been analyzed: additional heat exchange and emission reduction by catalysis. During normal operation of three low‐cost stoves, high levels of carbon monoxide (CO), volatile organic compounds (VOCs), and particulate matter (PM) concentration have been observed, having a major influence of the operator's behavior. The best case scenario with the retrofit systems resulted in a significant efficiency increase and as well a reduction of CO, VOCs, and PM.

Comparision of China’s volatile organic compound pollution management: a computable general equilibrium approach

ABSTRACTThe public health and ecological impacts of volatile organic compound (VOCs) pollution have become a serious problem in China, arousing increasing attention to emissions control. In this context, this paper analyses the effectiveness of VOC reduction policies, namely pollution charges and environmental taxes at the national and industrial sector levels. It uses a computable general equilibrium model, which connects macroeconomic variables with VOC emissions inventory, to simulate the effects of policy scenarios (with 2007 as the reference year). This paper shows that VOC emissions are reduced by 2.2% when a pollution charge equal to the average cost of engineering reduction methods – the traditional approach to regulation in China – is applied. In order to achieve a similar reduction, an 8.9% indirect tax would have to be imposed. It concludes that an environmental tax should be the preferred method of VOC regulation due to its smaller footprint on the macroeconomy. Other policies, such as subsidi...

Characteristics of using layered double hydroxides to reduce the VOCs from bituminous materials

Various types of molecules in the volatile organic compounds (VOCs) from bituminous materials were detected and analyzed by means of thermogravimetric-mass spectrometry (TG-MS) analysis. The effect of layered double hydroxides (LDHs) additives as VOCs inhibitor was also studied. The ion histogram of volatile components from bituminous binder was obtained through TG-MS analysis. Analysis results show that the environmental temperature has significant influence only on the volatile characteristics of smaller molecules in the pure bituminous binder. The effect of environmental temperature has been found marginal for the volatile speed of bigger molecules and LDHs modified bitumen binder.The obtained results regarding the pure bitumen and LDHs-modified bitumen demonstrate that LDHs modifiers have the potential to reduce VOC emissions. The reduction effect on different molecules or components varies. For smaller molecules, this effect on volatile speed is significant. LDHs affect the volatile speed of more carcinogenic volatile components to reduce more significantly for dichloroethane and naphthalene, compared with normal octane. The study findings indicate that a LDH percentage of 4% is an optimum for achieving the best emission reduction effect of VOCs for the selected binder, which is 40–60% percent reduction in VOCs.