We conducted research on the removal performance of various odor substances using a deodorizing agent, hypochlorite ion (OCl-), in odor emission sites where various odor-causing substances occur simultaneously. In experiments treating odor gases containing mixtures of aldehydes (acetaldehyde, n-butyl aldehyde, iso-valeraldehyde, propionaldehyde), sulfur compounds (hydrogen sulfide, methyl mercaptan, and dimethyl sulfide), and nitrogen compounds (ammonia and trimethyl amine), it was demonstrated that the introduced odor substances could be simultaneously removed when electrolyzed water was used. The overall removal efficiency was found to be significantly higher than when water alone was used. Particularly, it showed simultaneous effectiveness against acidic, neutral, and alkaline odor substances such as ammonia and hydrogen sulfide. Considering the positive aspects with regard to chemical safety, the use of salt instead of chemicals, and the continuous regeneration of the oxidizing agent, this environmentally friendly deodorization technology is expected to contribute to securing excellent odor removal capabilities and wide-ranging deodorization applications.

An odor is referred to or described as an unpleasant smell that creates a disagreeable atmosphere and may impinge on the quality of life of people. Most of the odors that stimulate the human sense of smell and engender feelings of discomfort and disgust are odors mixed with various chemicals substances. Among designated odor substances, acetaldehyde, propionaldehyde, butyraldehyde, n-valeraldehyde, and iso-valeraldehyde may cause an irritating and sour sensation and give rise to headache, dizziness, vomiting, and unconsciousness. These aldehyde substances are mainly discharged in high concentrations from food chemicals, petrochemicals, and printing industry sources. The odor control technologies applied to prevent odors from aldehydes are absorption, adsorption, as well as biological methods and combustion methods. The threshold concentrations of aldehydes are low so that odors can be easily experienced even at very low concentrations. It is not easy to control aldehydes due to their particular physicochemical properties and because aging and poor management of the odor prevention technology is usually only available. In this study, trends with regard to research efforts on the development of technology that is effective in treating aldehydes were summarized.

Cooking, especially meat and fish grilling, is one of the representative sources of indoor and outdoor particulate matter (PM). Most of PM emitted from cooking is ultrafine dust (PM2.5). Since odorous organic acids, aldehydes, and volatile organic compounds are absorbed by PM and discharged, restaurants and food service industries are major sources of odorous PM emission that cause odor nuisance complaints in cities. PM emitted from cooking also contains polycyclic aromatic hydrocarbons (PAHs), which are carcinogens. In this paper, the domestic PM emission status of biomass combustion, especially meat and fish grilling, was analyzed temporally and spatially. The results of previous studies on PM emission concentrations, emission rates, emission factors and their compositions from cooking were comprehensively summarized. In addition, the effects of food ingredient types, cooking methods, seasoning and oil addition and fuel types on the PM emission were reviewed. Much more PM was produced when cooking with charcoal rather than electricity or gas. The higher the fat content of food ingredients such as intestines, the higher the PM emission concentration and emission rate. There was a difference in the PM emissions depending on the cooking oil types, and the PM emission concentration was high when olive oil or corn oil was used. It is necessary to accumulate more information through followup studies on the emission concentrations, emission factors and properties of PM emitted from cooking activities. This information can be used for controlling odorous PM in restaurants and food service industries, and predicting the impacts of odorous PM on air quality and human health.

The adsorption method that is widely used in the field of odor control generally utilizes activated carbon. However, the development of an economical and efficient adsorbent is required due to the increased use of activated carbon and the high cost of raw materials. Accordingly, the use of waste as a raw material for new adsorbents is attracting attention both in Korea and abroad. In this study, the current status of domestic and overseas waste generation, characteristics of adsorbents, and research trends were investigated, and through this, it was found that a waste-derived adsorbent was an adequate substitute in terms of adsorption capacity and price compared to activated carbon.

Environmental fundamental facilities have different odor emission characteristics depending on the type of treatment facilities. To overcome the limitations of the olfactometry method, research needs to be conducted on how to calculate the dilution factor from the individual odor concentrations. The aim of this study was to determine the air dilution factor estimated from manually measured concentration data of individual odor substances (22 specified odor species) in three environmental treatment facilities. In order to calculate the optimum algorism for each environmental fundamental facility, three types of facilities were selected, the concentration of odor substances in the exhaust gas was measured, and the contribution of the overall dilution factor was evaluated. To estimate the dilution factor, four to six algorism were induced and evaluated by correlation analysis between substance concentration and complex odor data. Dilution factors from O municipal water treatment (MWT) and Y livestock wastewater treatment (LWT) facilities showed high level of dilution factors, because concentration levels of hydrogen sulfide and methylmercaptan, which had low odor threshold concentrations, were high. In S food waste treatment (FWT) facility, the aldehyde group strongly influenced dilution the factor (dominant substance: acetaldehyde, i-valeraldhyde and methylmercaptan). In the evaluation of four to six algorism to estimate the dilution factor, the vector algorism (described in the text) was optimum for O MWT and Y LWT, while the algorism using the sum of the top-three dominant substances showed the best outcome for S FWT. In further studies, estimation of the dilution factor from simultaneously monitored data by odor sensors will be developed and integrated with the results in this study.

This study aimed to investigate the characteristics of odor-causing substances in Yeosu national industrial complex, which is designated as an “Odor management Area,” in 2019 and the surrounding area. The sampling sites were divided into three areas: five sites within the industrial complex (Management area), one site within the borders of the complex (Boundary area), and two sites within residential areas (Affected area) affected by odors. The odor compounds were collected from March to September at dawn, daytime, and night. The analytical items were meteorological data, complex odor, legally-designated 22 odor compounds and other VOCs. Complex odor was exceeded on the limit three occasions at two sites in the management area. Ammonia, two types of sulfides, three types of aldehydes, and five VOCs were detected to be within the emission standards. Ammonia was the most frequently detected compounds. Aldehydes and sulfur compounds made a relatively high contribution to the level of odors. Therefore, aldehydes and sulfur compounds should be reduced first in order to prevent odors from occurring.

The effect of the change in air inflow velocity has been investigated at the opening of the malodor emission source to determine its influence on the Complex odor concentration. Both the Complex odor collection efficiency and concentrations were measured according to the change in airflow velocity. When the air inflow velocity was 0.1 m/s, it was observed that some of the generated gas streams were diffused to the outside due to low collection efficiency. In contrast, only the increased gas collection volume up to 0.5 m/s showed no substantial reduction of the Complex odor concentration, which indicates an increase in the size of the local exhaust system as well as the operation cost for the Complex odor control device. When the air inflow velocity reached 0.3 m/s, the Complex odor concentrations not only were the lowest, but the odorous gas could also be collected efficiently. The air inflow velocity at the opening of the malodor emission source was considered the key factor in determining the gas collection volume. Therefore, based on the results of this study, an optimal air inflow velocity might be suggestive to be 0.3 m/s.

This study was conducted to evaluate the applicability of a carrier media with natural minerals as packing material in a biofilter to remove odor-causing compounds. The carriers were prepared by mixing powdered zeolite, barley stone, and clay. They have a pellet type with a length of 5m m to 10 mm, 3.2 m2/g of a specific surface area, and 0.04 cm3/g of a pore volume. The adsorption capacity and the biodegradation by biomass formation on the media were experimented with toluene and ammonia as the test compounds. The carrier possessed the ability to adsorb toluene and ammonia. The adsorption capacity of toluene and ammonia at the inlet concentration of 100 ppmv was 58 g/g and 96 g/g, respectively. In the biofilter using the carrier as the packing material, the biofilter performances were different depending on the supply of moisture and liquid-nutrient. The critical loading was found to be 33.13 g/m3/hr for toluene removal and 6.5g /m3/hr for ammonia removal even when no nutrients were supplied. The proposed material has been confirmed to be capable of adsorbing inorganic and organic compounds, and can be effectively applied as packing materials for the biofiltration.

Odor emitted from the degradation process of food waste is a common cause of public complaints, and appropriate odor treatment methods need to be implemented. In this study, a hybrid plasma catalyst system was applied to treat individual odorous compounds including acetaldehyde and hydrogen sulfide, which are known to be major odor compounds produced from food waste. MnOx catalysts were prepared by varying Mn/support loading ratios, and surface analyses showed that the Mn_5% catalyst achieved the highest performance because dominant manganese oxide species on the surface of the catalyst was found to be Mn2O3, Using the catalyst, the removal rate of hydrogen sulfide steadily increased as the space velocity in the MnOx catalyst reactor decreased. Meanwhile, the removal rate of acetaldehyde did not increase significantly when decreasing the space velocity more than 24,000 hr-1. Following the catalyst experiments using the individual odorous compounds, the hybrid system was applied for testing odor treatment of actual food waste. The actual food waste study showed that both hydrogen sulfide and acetaldehyde were steadily removed; hydrogen sulfide was removed almost completely during the initial 30-minute period, while the acetaldehyde removal was started after the decrease of hydrogen sulfide. In addition, it was confirmed that the dilution-to-threshold for odor reduced from 2,080 D/T to 300 D/T during the initial period. In conclusion, the plasma and Mn2O3 catalyst system can be applied in food waste collection containers to effectively control odor problems.

This study was conducted to separate microorganisms with excellent odor component decomposition ability from nature. Microorganisms growing sulfur and ammonia compounds as substrates were isolated and identified in the tidal flat of Suncheon Bay. The strain YUN4 cultured on ammonia and sulfur compound substrates was found to have 100% genetic homology to Streptomyces fulvissimus. The optimum growth temperature of YUN4 was 20oC to 40oC, and the optimum pH was investigated in the range of pH 5 to pH 9. In addition, in order to evaluate the ability to reduce odor, after mixing the culture strain with each concentration of 1%, 5%, and 10% in the malodor generating sample, the efficiency of malodor reduction was evaluated after 30 minutes. As a result, the ammonia decomposition efficiency was 82.4%~93.9%, and hydrogen sulfide was 88.7%~94.9%.

This study was conducted to analyze the characteristics of odorous components that have been generated from the downtown sewer system based on twenty-three survey items for complex odor and designated offensive odor. As a result of the research, the contribution rates for the causative materials of the odor indicated 73.5% of hydrogen sulfide, 26.0% of methyl mercaptan, 0.4% of dimethyl sulfide, and 0.1% of dimethyl disulfide. The occurrence for the odorous materials according to sampling site revealed data of which contribution rates showed 56.9% of hydrogen sulfide and 36.8% of methyl mercaptan from the combined sewer system in the business district; whereas the combined sewer system in the residential area showed 16.4% of dimethyl sulfide and 4.3% of dimethyl disulfide. The seasonal occurrence rate of the odor materials was observed higher in summer and lower in winter And, the combined sewer system in the business district recorded the highest concentration of 4.61 ppm of hydrogen sulfide among the sampling site. An hourly occurrence rate for the odor materials consistently showed the greatest increase between 11:00 and 14:00 at each location and showed a decreasing tendency afterward.

Most of the odorous substances generated in public environment facilities are treated using a local exhaust ventilation system. This study assessed the leakage of odorous substances by measuring design criteria, collected air volume, and complex odor in the unit process of sewage treatment facilities. The closer the guideline/design operation airflow ratio of each odor source is to 1.0, the more identical the guideline:design:operation airflow. The average air volume ratio of the facilities under the study was 0.95~0.99 for the MBR process and 0.29~0.68 for the BNR process. As a result of comparing the types of wastewater treatment processes, the leakage of odorous substances was about 9.7 times higher in the BNR process (192,732 m3/min) than in the MBR process (19,838 m3/ min). In this study, it was found that the following two means are important for the proper collection and prevention of odorous substances. The first is the estimation of collection air volume with consideration to the characteristics of the odor source (temperature, odor generation condition, etc.). The second is the design and operation of the local exhaust ventilation system.

The concentrations of volatile organic compounds (VOCs) and odor-inducing substances were measured using selected ion flow tube mass spectrometers (SIFT-MS) and a drone equipped with an air quality monitoring system. SIFT-MS can continuously measure the concentration of VOCs and odor-inducing substances in realtime without any pre-treating steps for the sample. The vehicle with SIFT-MS was used for real-time measurement of VOC concentration at the site boundaries of pollution sources. It is possible to directly analyze VOCs concentration generated at the outlets by capturing air from the pollution sources with a drone. VOCs concentrations of nine spots from Banwol National Industrial Complex were measured by a vehicle equipped with SIFT-MS and were compared with the background concentration measured inside the Metropolitan Air Quality Management Office. In three out of the nine spots, the concentration of toluene, xylene, hydrogen sulfide, and methyl ethyl ketone was shown to be much higher than the background concentration. The VOCs concentrations obtained using drones for high-concentration suspected areas showed similar tendencies as those measured using the vehicle with SIFTMS at the site boundary. We showed that if both the drone and real-time air quality monitoring equipment are used to measure VOCs concentration, it is possible to identify the pollutant sources at the industrial complex quickly and efficiently check sites with high concentrations of VOCs.

n-Butanol is used to assess how odor intensity correction affects judges’ evaluation of the odor intensity based on the concentration. The odor intensity correction effect is verified by using three types of test solutions which are used for the selection of judges based on their concentration levels. The correction effect is statistically analyzed according to gender, odorant type, and concentration on the group and individual level. The result shows that n- Butanol correction affects the odor intensity evaluation for three odorants in different ways. In most cases, n- Butanol correction increases the panelists' sensitivity to the odor intensity change, and results to be close to the theoretical value. The female panelists can more accurately evaluate the sourness intensity of acetic acid after n- Butanol correction. All panelists regardless of gender can more accurately evaluate the fishiness intensity of trimethylamine after n-Butanol correction. For evaluating the caramel smell intensity of methylcyclopentenolone, a full panel without n-Butanol correction is recommended. Therefore, n-Butanol correction should be included in the process of judge selection and the odor intensity assessment.

In this study, real-time monitoring of air quality using a real-time mobile monitoring system was conducted to identify the emission characteristics and current status of air pollutants and odorous substances that are mainly generated in domestic dyeing industrial areas and to trace the pollutant sources. The concentration of toluene in the industrial area was detected up to 926.4 ppb, which was 3 to 4 times higher than that of other industrial areas. The concentration of methylethylketone was 124.7 ppb and the concentration of dichloromethane was 129.5 ppb. Acrolein concentration was highest at E point at 521.6 ppb, methanol concentration was highest at D point at 208.8 ppb, and acetone concentration was highest at M and N points at 549.3 ppb. The most frequently detected concentration of pollutants in the air quality monitoring results in the industrial area was, in descending order, toluene > methanol > acrolein > dichloromethane > acetone, which was similar to the chemical emissions used in the industrial area by the Pollutant Release and Transfer Register data. The concentration of odorous substances measured in real time was compared with the concentration of minimum detection, and the concentration of hydrogen sulfide was about 10 times higher than the concentration of minimum detection at A point, which was judged to be the main odorous cause of A point. In the future, if the real-time mobile measurement system is constructed to automatically connect wind direction/wind speed, PRTR (Pollutant Release and Transfer Register) data and SEMS (Stack Emission Management System) data, etc., it was judged that more accurate monitoring could be performed.

The emission of odor, characterized by the combustion conditions and biomass types resulting from the use of a biomass incinerator, was analyzed. The following biomass types were considered: bark, board waste, sawdust, wood flour, wood fiver, wastewater sludge, and timber wastewater. As a study method, the physico-chemical characteristics of each biomass type were analyzed to predict the potential substances that might be emited under incomplete combustion conditions. And, the emission components of odor emission by biomass were analyzed at the laboratory level using a combustion device. In addition, the characteristics of the contaminant (odor) emission per mixture ratio of biomass were analyzed in a stoker incinerator that is in operation in an actual establishment at a scale of 300 ton/day. In the biomass emission experiment using the combustion device at the laboratory level, the major substances such as Acetic acid, Styrene, Toluene, Benzene, Dichloromethane, etc. were analyzed, and these components were determined to increase odor index. VOCs measurement in the outlet of the stoker incinerator indicated that Acetaldehyde, Ethanol, Acetonitrile, Ethyl acetate, Toluene, etc. were detected as the major substances. These were similar to the emission substances presented by the experiment that had investigated emissions by biomass type. A study on the Effect of Operational Conditions in biomass stocker incinerator on the concentration of odorous materials emitted from stack showed a close relationship between the input by biomass type and urea, temperature in the incinerator, and the tendency to emit/produce odor.

Odor emitted from food waste is commonly known as a severe problem, and needs to be controlled to minimize public complaints against food waste collection systems. In this study, ozone oxidation with manganese oxide catalyst, which is known to effectively treat odorous substances at room temperature, was applied to remove acetaldehyde and hydrogen sulfide, the model odorous compounds from food waste. In addition, the effect of relative humidity (RH) on the ozone/catalyst oxidation was tested at 40%, 60%, and 80%. When the catalyst was not applied, the removal of acetaldehyde was not observed with the ozone oxidation alone. In addition, hydrogen sulfide was slowly oxidized without a clear relationship under RH conditions. Meanwhile, the ozone oxidation rates for acetaldehyde and hydrogen sulfide substantially increased in the presence of the catalyst, but the removal efficiencies for both compounds decreased with increasing RH. Under the high RH conditions, active oxygen radicals, which were generated by ozone decomposition on the surface of the catalyst, were presumably absorbed and reacted with moisture, and the decomposition rate of the odorous compounds might be limited. Consequently, when the ozone oxidation device with a catalyst was applied to control odor from food waste, RH must be taken into account to determine the removal rates of target compounds. Moreover, its effect on the system performance must be carefully evaluated.

We analyzed volatile organic compounds (VOCs) of petroleum-based laundry solvents in closed systems by static headspace analysis and investigated the emission characteristics of odorous compounds emitted from organic solvents in the small-scale dry cleaning process. The compounds containing eight to eleven carbon atoms were analyzed to account for 96.92% of the total peak area in a GC-MS chromatogram. It was found that the compounds with ten carbon atoms showed the largest proportion. In the small-scale dry cleaning process (3 kg of laundry and 40 min of drying time), a total of 36 VOCs was quantified, and the odor contribution of these compounds was evaluated. The sum of the odor quotient (SOQ) was analyzed up to 151±163 in the first 12 min of operation. The main odor-causing compounds were acrolein, ethylbenzene, hexane, acetone, and decane, and their odor contributions were 32.28%, 13.47%, 10.52%, 10.20%, and 8.08%, respectively.

We developed a wet scrubber by applying cyclone flow to the gas flow and using a spiral filter structure. While the size of a new scrubber was about half that of a conventional scrubber, the device showed relatively high efficiency in pollutants removal such as particulate matter and compounds inducing odor. The new scrubber installed in a plating industry showed a higher removal efficiency of about 5% for dust, about 23% for hydrogen chloride, and about 23% for sulfur dioxide compared to the conventional scrubber. Plurality of tubes in the spiral filer housing are arranged to be vertically shifted from each other. Because the upward residual gas does not directly rise vertically, the residence time of gas between the filter plates is extended. Thus, the purification efficiency of the pollutants was enhanced in the new scrubber. In addition, the new scrubber developed in this study is more cost effective because the cost saving in manufacturing it compared with a conventional scrubber increases with increasing the size of equipment. It is expected that a scrubber with better dust collecting efficiency can be obtained by carrying out a study in connection with facilities capable of controlling acidity of washing water.