Airborne bacteria in mushroom growing environments are a potential risk of contamination in commercial mushroom production. Controlling contamination in mushroom farms requires understanding the bacterial ecology in the cultivation environment. This study was conducted to investigate the concentration and species diversity of floating bacteria in a thermophilic mushroom cultivation room. Temperature, humidity, temperature, humidity, and bacterial concentration measurements were performed in April and May 2022 for a Pleurotus ostreatus cultivation house, in July and August 2023 for a Pleurotus sajor-caju and a Agaricus blazei cultivation house, and in June, July and August 2023 for a Pleurotus pulmonarius, Pleurotus sajor-caju and Calocybe indica cultivation house. The airborne bacterial concentration was 5.27 × 103~105 CFU/m3, 3.81 × 102 ~1.37 × 103 CFU/m3, and 2.55 × 102 ~1.37 × 102 CFU/m3 in the three cultivation houses, respectively. A total of 23 genera and 37 species of airborne bacteria were isolated from the three mushroom cultivation houses. 12 genera and 18 species were identified from P. ostreatus cultivation house. Furthermore, 4 genera and 4 species were found from A. blazei and C. indica cultivation house. In addition, 11 genera and 18 species were isolated from P. pulmonarius, P. sajor-caju and C. indica cultivation house. Among the bacteria isolated, the Bacilli class was the most common, followed by Gammaproteobacteria. Among the 37 bacterial species, it was determined that Bacillus cereus, B. licheniformis, Cedecea neteri, Exiguobacterium acetylicum and Raoultella terrigena could negatively affect humans or foodstuff. Cedecea neteri is also known to cause diseases among mushrooms.

This study evaluated the effectiveness of odor reduction when spraying inside the Bio-curtain (hereinafter referred to as curtain) according to the exhaust fan operating rate. Spraying is a main factor affecting the ability to odor reduction of curtains. The curtain (total area: 37.9m3) was constructed with two layers of light-shielding screens stretched over a rectangular parallelepiped structure installed around an exhaust fan (630 mm) on the side wall of a pig barn. Air samples for odor analysis were collected from inside the pig barn and outside the curtain. The main odorous compounds such as volatile fatty acids, phenols, indoles, and ammonia were measured. The odor reduction effectiveness was evaluated by total odor activity values (TOAVs) summed to the odor activity values of each odorous compounds. Depending on the exhaust fan operating rate, the reduced rate of TOAVs gradually decreased to the range between 15.67% and 68.80%. Because the contact time between the spraying liquid and the air velocity of the exhaust fan becomes shorter (or there is a reduction in liquid to gas flow ratio) as the exhaust fan operating rate increases. The results of this study can be used as basic data for research into spraying conditions to improve the odor reduction effectiveness of curtains.

Yeosu National Industrial Complex is one of Korea’s representative petrochemical industrial complexes where crude oil refining and petrochemical companies are concentrated. According to the results of the 2021 chemical emissions survey, during the process of manufacturing, storage, and transportation at the Yeosu National Industrial Complex, various hazardous chemicals, including hazardous air pollutants, volatile organic compounds and odorous substances are being emitted into the air, affecting the surrounding environment and the health of residents. The Ministry of Environment is applying strengthened standards by designating the Yeosu National Industrial Complex as an air conservation special measure area and establishing odor management areas to manage the air environment. Nevertheless, odor complaints continue to be registered and related complaints increase when turnaround work is carried out. Since air emissions are not counted during periods of turnaround as normal operations are temporarily suspended, it was difficult to establish policies to reduce odor complaints because the source of emissions and emission quantities cannot be ascertained with certainty. In this study, the extensive Yeosu National Industrial Complex was subdivided into 4 areas using a mobile vehicle equipped with PTR-ToF-MS capable of real-time analysis without sample pretreatment being carried out. Measurements were repeated during the day, night, and dawn while moving around the internal boundary of the plant and the boundary of each region where turnaround activities were being carried out. As a result, the recorded measurement for acrylonitrile was the highest at 6340.0 ppb and propyne and propene were measured the most frequently at 128 times each. Based on these results, it will be possible to help reduce emissions through process improvement by efficiently operating air measurement networks and odor surveys that conduct regular measurements throughout the year and providing actual measurement data to the plant. Also, it will help reduce odor complaints and establish systematic air management policies.

In order to determine the future direction of Busan City’s tree planting policy in accordance with changes in automobile fuel and air pollutants, this study selected representative tree species planted in Busan and identified the biogenic volatile organic compounds (BVOCs) emission rate and characteristics of each species. First, representative tree species were selected for each street tree species, forest tree species, and park tree species, and the emission rate and major components of BVOCs were investigated for each tree species. Furthermore, by comparing the ozone generation potential (POCP) for each tree species, tree species with a low emission rate were selected. According to the POCP comparison, P. yedoensis, G. biloba, Z. serrata and C. retusus were selected as roadside tree species, P. densiflora and C. obtusa as forest species, and A. palmatum, C. japonica, and Q. myrsinaefolia were deemed suitable for park species. However, in the case of P. occidentalis, Quercus, and M. glyptostroboides, the emission rates of BVOCs were found to be high. Despite this, these tree species were found to display excellent CO2 absorption and carbon storage. The concentration of NOx in the city center is likely to decrease due to the current trend of transitioning to eco-friendly cars worldwide, resulting in less cars that rely on fossil fuels. Therefore, in the current climate where NOx emissions are still high, planting tree species with a low BVOCs emission rate would be an optimal approach. On the other hand, if the NOx concentration in the city is found to be very low due to changes in automobile fuel use, planting tree species with excellent BVOCs emission capacity and CO2 absorption would be ideal.

The odors emitted from wastewater treatment plants are not only a health and hygiene problem, but can also lead to complaints from residents and have wider social ramifications such as bringing about falling property values in the surrounding area. In this paper, based on the data measured at domestic and overseas wastewater treatment facilities, the concentrations of complex odors and odorous compounds were compared for each treatment/process: primary treatment, secondary treatment, and sludge treatment processes. Odor compounds that contribute greatly to complex odors were summarized for each process. In addition, the characteristics of odor wheels for each wastewater treatment process, which provide both chemical and olfactory information regarding odors, were reviewed. For domestic wastewater treatment facilities, the complex odor concentrations (unit, dilution factor) of the primary and secondary treatment processes were 4.5-100,000 (median, 32.1) and 2.5-30,000 (median, 10.7), respectively. However, the complex odor concentrations in the sludge treatment process were 3.0-100,000 (median, 118.7), which was more than three times higher than that in the wastewater treatment process. In the wastewater treatment process, those odor compounds making the greatest contributions to complex odors were sulfur-containing compounds such as hydrogen sulfide, dimethyl sulfide, and dimethyl disulfide DMS. In order to properly manage odors from wastewater treatment plants and minimize their impact, it is important to understand the status of odor emissions. Therefore, the compositions and concentrations of odors from wastewater treatment processes and odor wheel information, which are reviewed in this paper, are used to evaluate the potential risk of odor from wastewater treatment facilities in order to derive strategies to minimize odor emissions. Moreover, the information can be usefully used to introduce the best available technology to reduce odors emitted from wastewater treatment facilities.

This study was conducted to verify the reliability of volatile organic compounds (VOCs) data derived from Selected Ion Flow Tube-Mass Spectrometers (SIFT-MS) measurements. In the previous study, the measurement reliability was validated using simultaneous measurements by SIFT-MS and gas chromatography-mass spectrometry (GS-MS), but in order to ensure more accuracy, and additional analysis was conducted by diluting standard gases (2 ppm) consisting of 10 types of VOCs mainly measured in industrial complexes (concentrations ranged from 0 to 500 ppb). As a result of 2 experiments, the SIFT-MS showed linearity and produced a coefficient of determination of over 0.99 for all cases. SIFT-MS has secured high measurement reliability, and it is considered to be able to efficiently manage VOCs emitted in industrial complexes.

The present study was carried out to investigate the concentration and species diversity of airborne fungi in thermophilic mushroom cultivation houses. Fungal concentration measurements were performed in April and May 2022 for a Pleurotus ostreatus cultivation house, in July and August 2023 for a Pleurotus sajor-caju and Agaricus blazei cultivation house, and in June, July and August 2023 for a Pleurotus pulmonarius, Pleurotus sajor-caju and Calocybe indica cultivation house. The airborne fungal concentration was 2.95 × 102 CFU/m3~105CFU/m3, above 105CFU/m3, and 1.12 × 103 CFU/m3~ 9.17 × 103 CFU/m3 in the three cultivation houses, respectively. A total of 8 genera and 22 species of airborne fungi were isolated from three mushroom cultivation houses. 5 genera and 7 species were identified from P. ostreatus cultivation house. Furthermore, 4 genera 6 species were found from A. blazei and C. indica cultivation house. In addition, 5 genera and15 species were isolated from P. pulmonarius, P. sajor-caju and C. indica cultivation house. Among the fungi isolated, the class of Eurotiomycetes was the most common. Among the 22 fungal species, Aspergillus flavus, A. ochraceus A. sydowii, A. tubingensis, A. westerdijkiae, Penicillium brevicompactum, P. citrinum, and P. steckii have been reported as harmful species to mushrooms, food, and human.