This paper aims to review the odor removal performance and operating parameters of pilot and full-scale chemical scrubbers, bioscrubbers, biofilters, and biotrickling filters for odor control in wastewater treatment plants. Based on the performance of full-scale facilities installed in wastewater treatment plants, empty-bed residence times were the shortest for bioscrubbers (7.5±2.5s), followed by chemical scrubbers (20±8.1s), biotrickling filters (22.2±26.2s), and biofilters (48±30s). The removal efficiencies of complex odors by biofilters, biotrickling filters, bioscrubbers, and chemical scrubbers were 97.7±1.9%, 87.7±15.6%, 89.0±9.0%, and 70.0%, respectively. The investment cost was the lowest for biofilters, followed by biotrickling filters, bioscrubbers, and chemical scrubbers. In addition, the operating costs of these deodorization technologies were in the following order: biofilters < bioscrubbers and biotrickling filters < chemical scrubbers. However, most studies on odor control for wastewater treatment processes have been conducted on a laboratory scale with model odors (single odorous compound or mixtures of 2-3 odorous compounds). Therefore, field research to develop deodorization technologies for wastewater treatment plants should be more actively conducted to accumulate data for the design and operation of full-scale deodorizing systems.

This study examines the correlation between livestock odor civil petitions and the establishment of malodor control areas in Jeju Special Self-Governing Province, focusing on swine farms where numerous civil petitions regarding malodors have been received. After the designation of the malodor control areas, high odor concentrations occurred in Aewoleup and Jocheon-eup, and the odor concentration decreased in other areas. The number of civil petitions shows a consistent annual trend, with increased petitions from March, peaking during summer (July and August), and decreasing from September into winter. In Jeju-si, there were many civil petitions in Hallim-eup and Aewol-eup where there were many malodor control areas. However, in Seogwipo-si, there were also many civil petitions in Pyoseonmyeon, where there is no malodor control area. Additionally, we compared the average multiple of compound malodors and the rate of exceeding the maximum allowable emission level for compound malodors with the number of livestock malodor civil petitions to assess the actual state of malodors. The results reveal a stronger correlation between the number of civil petitions and the rate of exceeding the compound malodors allowable emission level than the average multiple for compound malodors. These findings provide valuable insights into addressing livestock odor concerns and enhancing malodor control measures in Jeju Island.

This review comprehensively summarizes the livestock odor reduction method by dietary manipulation, in-housing management, and manure management. The gut microbial metabolism of animals can be stimulated by low-crude protein feeding and the addition of probiotics, enzymes, plant extracts, and/or organic acids to their feed. These methods can result in reduced odor emissions from manure. For in-housing management, it is important to maintain the proper breeding density in the barn facilities, regularly remove dust and manure, and periodically clean the barn facilities. A barn using litter on the floor can reduce odor at a relatively low cost by adding adsorbents such as zeolite, biochar, etc. Although masking agent spraying can be the simplest and quickest way to control odors, it is not a fundamental odor mitigation strategy. Odor emissions can be reduced by installing covers on manure slurry storage facilities or by acidifying the manure slurry. It is necessary to install a solid-liquid separator in an enclosed facility to minimize odor emissions. Other methods for reducing odor emissions include covering manure composting plants with semi-permeable membranes or using reactor composting technology. In order to minimize odor emissions in the liquid manure composting, sufficient oxygen must be supplied during the fermentation process. Furthermore, the odor reduction effect can be achieved through the liquid manure pit recharge system which supplies matured liquid manure fertilizer to the slurry pit in the pig house.

This study was carried out in order to provide suggestions with regard to optimal control methods for various odor emission facilities (162 companies and 26 industrial classifications) through comparative analysis of effective odor treatment technologies for each type of odor substance by literature reviews, based on measured 22 odor substance data for 162 samples taken from A city. The industrial classification of Pulp showed the highest odor quotient (7,589 as average value) and was followed by the industrial classifications of Wastewater, Woods, and Furniture, indicating average odor quotient values of 2,361, 1,396 and 1,392, respectively. Absorption using chlorine dioxide and sodium hydroxide can be an optimal treatment method to remove the odor substances of sulfide and aldehyde groups. Biofilers with microbial communities will be effective to remove odors caused by volatile organic compounds (VOCs) and an absorption method using sulfuric acid is proper for the removal of odor substances caused by nitrogens.

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.

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.

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.

Environmental treatment residues become valuable waste byproducts like biomass when an environmental infrastructure necessary for recycling is effectively developed. In this study, an environmentally friendly sewage sludge sorbent was developed in a sewage treatment plant by carefully processing the sewage sludge generated from sewage treatment plants. In order to increase the adsorption efficiency, coffee ground waste was added to the adsorbent as an additive and the adsorbate used in the adsorption experiments was acetaldehyde as organic waste. It could be found from the experiment that the adsorbent of the sewage sludge was adsorbed more easily at the carbonization temperature of 600℃. In addition, adsorption experiments showed that the breakthrough time reached to 85, 110, and 130 minutes at 3:1, 2:2, and 1:3, respectively, depending on the content ratio of the sewage sludge and coffee waste. Therefore, the amount of acetaldehyde adsorption increased with the increase in the amount of coffee grounds in the mixture. It could be also be found that the addition of the coffee grounds as an additive to increase the adsorption capacity of the sewage sludge adsorbent is advantageous for adsorption.

Due to economic feasibility and recycling policy of wastes, various types of residues have been studied particularly for high valued materials, such as gas adsorbents. In this study, the preparation of an adsorbent using the waste from coffee manufacturing process was attempted, and the removal efficiencies the odor and VOCs with acetaldehyde were quantitatively evaluated. The obtained coffee adsorbent had a specific surface area ranging from 400~1024 m2/g, the adsorption amount at the largest specific surface area was about 92.6 mg/g for acetaldehyde. The adsorption time by the characteristics of the adsorbents, such as pore, pore volume and the amount of adsorbent was also measured. This was to determine whether or not coffee adsorbents have any performance as adsorbent.

A biofilter filled with sintered glass media and wood bark media were developed and tested. Acetic acid and ammonia added in brewery wastewater were used as an artificial odor source. The Reynolds’ number (NRe) was below 130 in the loading range of 3~5 m3/m2-min, while the pressure drop was less than 6 mmH2O. The average removal efficiency of acetic acid was 87.6% and 71.5% at surface loading rate of 3.1 m3/m2-min and 4.4 m3/m2- min, respectively. The acetic removal capacities were 8.1~14.3 g/m3-min with the mass loading rates of 11.7~22.4 g/m3-min, indicating very high performance. However, the acetic removal capacity was sharply decreased at the mass loading rate of 20 g/m3-min. The average removal rate of ammonia was 38% and 25% at the surface loading rates of 3.1 m3/m2-min and 4.4 m3/m2-min, respectively. The ammonia removal capacity was 0.47~0.88 g/m3-min in the range of 11.7~22.4 g/m3-min mass loading rates. The intensity of complex odor was also decreased based on the findings in the measurement using the direct olfactory method and the GC analysis.

In this study, the odor causing in the under-fired charbroiling restaurant was reported in literature investigation,pilot test and field experimental verification. The charbroiling restaurant causes odor complaints of Neighbors soefficient reduction method is requested. Acetaldehyde, ammonia, sulfur compound and the oil mist of white smokeare found to cause odor from the charbroiling restaurant. Pilot test results show that in the removal efficiency ofodor, Electrostatic Precipitation was 67.4%, absorption was 81.2%, adsorption was 74.2% and the ElectrostaticPrecipitation & Adsorption the hybrid system with 85.7% respectively. In the same condition of the hybrid system(Electrostatic Precipitation & Adsorption), the odor removal efficiency were higher when the design parameterssuch as the discharge voltage and current were high. The process efficiency were higher when as the implanterpole was cylindrical. However, the process efficiency rapidly reduced due to the contamination of the processcomponent or material, as the operating time of the equipment is increased. Therefore, fixed maintenance and repairof the equipment is found to be are very important, for long term operation. Therefore, as the experimental resultof this study, applying hybrid system removed odors caused in under-fired charbroiling restaurant which areunregulated, is more effective device that settle civil complaints and preserve environment.

This paper presented experimental results for circulation type UV-TiO₂ photocatalytic oxidation process. We have developed UV-TiO₂ photocatalytic oxidation process with activated carbon to control odor and VOCs in indoor and industrial applications. In this study, common indoor air pollutants, namely ammonia, formaldehyde, hydrogen disulfide, toluene were selected to investigate their efficiencies for UV-TiO₂ photocatalytic oxidation. In high concentration test, the decomposition efficiency was high in order as ammonia, toluene, formaldehyde, hydrogen disulfide. Three type of individual processes are tested for ability to increase decomposition efficiency. UV-TiO₂ photocatalytic oxidation combined process with activated carbon was excellent among the three type processes without reference to gas species. It was considered that this circulation type process will overcome short retention time for treatment for UV-TiO₂ photocatalytic oxidation. It will promise that this circulation type UV-TiO₂ photocatalytic oxidation combined process can apply indoor and industrial applications to remove odor and VOCs quickly.