Emission Characteristics and Ozone Formation Potential Assessment of VOCs from Typical Metal Packaging Plants

With the rapid development of metal packaging, volatile organic compounds (VOCs) emissions from the packaging processes are also increasing gradually. It is necessary to research the characteristics of VOCs emissions from such important industrial source and its impact on the possible ozone formation. In this research, three typical metal packaging plants were selected, VOCs emission characteristics were investigated, and their ozone formation potential were evaluated by using maximum incremental reactivity (MIR) coefficient method. The results showed that the VOCs emission characteristics of the selected targets were obviously different. VOCs emitted from plant A and B were mainly oxygenated hydrocarbons, which accounted for 85.02% and 43.17%, respectively. Olefins (62.75%) were the main species of plant C. 2-butanone (82.67%), methylene chloride (23.00%) and ethylene (36.67%) were the major species of plant A, plant B and plant C, respectively. The OFP (ozone formation potential) value of plant B (120.49 mg/m3) was much higher than those values of plant A (643.05 mg/m3) and plant C (3311.73 mg/m3), in which para-xylene, meta-xylene, acetaldehyde and ethylene were the main contributors. The difference in OFP values indicated that water-based ink and water-based coatings should be recommended for large scale application due to less VOCs emission and low ozone formation contribution.

Evaluation Model for Particulate Matter Emissions in Korean Construction Sites

Particulate matter (PM) has caused serious environmental issues in Asia, and various policies for systematic management of PM based on evaluation of the characteristics of emissions are being discussed. In Korea, where the damage of PM from construction sites is severe, only regulatory policies according to the concentration are being implemented; however, there is no policy for the quantitative management of PM. Therefore, this study aimed to derive and propose an emission evaluation model to be used for the establishment of management policies for construction site PM emissions in South Korea by assuming structures as manufactured products. Therefore, this study derived a method of calculating the PM10, PM2.5, NOx, SOx, and VOCs emission factors for each type of equipment in construction sites and then estimated annual total emissions. In addition, this paper put forth a method for offsetting emission permission standards as the criteria for evaluating the adequacy of the estimated emissions. Finally, a model algorithm was proposed for evaluating emissions in advance during the construction planning phase by comparing the PM10, PM2.5, NOx, SOx, and VOCs emissions in construction sites with established standards; the supplementary point of the algorithm is discussed for further studies.

Emission Characteristics of VOCs during Asphalt Pavement Construction

As the important part of expressway, the construction technology of asphalt pavement will contribute to the production of greenhouse gases and other volatile organic compounds (VOCs), which has a significant impact on the environment. In order to further analyze the composition, distribution and release of VOCs during asphalt pavement construction, the VOCs emission during paving and rolling were measured through field investigation and sampling. The results show that there are approximately 100 kinds of VOCs substances detected due to the complex organic component of asphalt binder, which is a critical factor to influence the VOCs emission during asphalt pavement construction. During the paving process, the largest VOCs release is 1015.05 ug/m3. With the increase of rolling times, the pavement temperature gradually decrease, and the VOCs emission drops to 266.73 ug/m3. The content of the 10 kinds of substances with the highest concentration accounts for more than 50% of the total VOCs content, in which the proportion of aliphatic hydrocarbons (ALH) and oxygenated hydrocarbon (O-HYD) of the paving process are the highest, while the proportion of aromatic hydrocarbons (ARH) is dominated in the rolling process. The results are vulnerable to the external environment, especially at lower emission level. The relevant research results have certain guiding significance for the control and treatment of harmful gas emission in the construction process of asphalt pavement.

Emissions of Volatile Organic Compounds (VOCs) from an Open-Circuit Dry Cleaning Machine Using a Petroleum-Based Organic Solvent: Implications for Impacts on Air Quality

Volatile organic compounds (VOCs) are known to play an important role in tropospheric chemistry, contributing to ozone and secondary organic aerosol (SOA) generation. Laundry facilities, using petroleum-based organic solvents, are one of the sources of VOCs emissions. However, little is known about the significance of VOCs, emitted from laundry facilities, in the ozone and SOA generation. In this study, we characterized VOCs emission from a dry-cleaning process using petroleum-based organic solvents. We also assessed the impact of the VOCs on air quality by using photochemical ozone creation potential and secondary organic aerosol potential. Among 94 targeted compounds including toxic organic air pollutants and ozone precursors, 36 compounds were identified in the exhaust gas from a drying machine. The mass emitted from one cycle of drying operation (40 min) was the highest in decane (2.04 g/dry cleaning). Decane, nonane, and n-undecane were the three main contributors to ozone generation (more than 70% of the total generation). N-undecane, decane, and n-dodecane were the three main contributors to the SOA generation (more than 80% of the total generation). These results help to understand VOCs emission from laundry facilities and impacts on air quality.

Environmental Impact on VOCs Emission of a Recycled Asphalt Mixture with a High Percentage of RAP

Recycling of reclaimed asphalt pavement (RAP) has gradually emerged as a hot topic in the current research of building materials. Manufacturing the recycled asphalt mixture with a high RAP content still remains a major challenge due to the problem of inferior water damage resistance and fatigue cracking resistance. The aim of this study is to evaluate the servicing performance of recycled asphalt mixture with high percentage of RAP and assess its environmental impact on volatile organic compounds (VOCs) emission. To further explore the intrinsic factor on the performance of a recycled asphalt mixture, the mixed asphalt binder with a different content of extracted RAP binder was firstly investigated. The results show that the larger the content of RAP binder, the lower the mechanical indexes and VOCs emission. There exists an internal relationship between the chemical composition and VOCs release behavior with the variation of the recycled asphalt binder content. Based on the results of mixed recycled asphalt binder, the road servicing performance of a rather high utilization of RAP (i.e., 50%, 60%, and 70%) was assessed. It was found that the reuse of RAP aggregates has little influence on the volume performance of recycled asphalt mixture, and servicing performances still meet the construction requirements in spite of a descending trend. Moreover, a significant reduction effect on VOCs emission was found in the mixing stage of recycled asphalt mixture, indicating that the VOCs emission can be decreased by 94.82% when the content of RAP aggregates increases to 70%. The recycling of RAP with a high content contributes to the sustainable development of road engineering and the construction of green pavements.