This review paper aimed to comprehensively assess the ventilation methods and ventilation rates of livestock sheds, various livestock odor mitigation technologies, and the design flow rate of odor mitigation devices. The most efficient ventilation method for livestock odor control was found to be mechanical ventilation. When livestock odor is at its most severe during summer, ventilation systems are operated at the maximum ventilation rate, which is 5-25 times higher than the ventilation rate in winter. Therefore, the mitigation facilities of livestock odor must be designed while considering the maximum ventilation rate. There is a significant amount of research data on various livestock odor control technologies using various physical, chemical, biological, and complex technologies applied to livestock farms. Biofiltration and photocatalytic oxidation are considered the most promising methods due to their cost-effectiveness and simplicity. Biofiltration is effective for removing hydrophilic odors, but requires improvement for the efficient removal of hydrophobic odors and the control of accumulated excess biomass. The advantages of the photocatalytic oxidation method include its excellent hydrogen sulfide and ammonia removal rates and relatively low ozone emissions. However, it requires technology to reduce nitrous oxide emissions. Investment in installing and operating these odor mitigation technologies is only realistic for large-sized farms. Therefore, it is imperative for small and medium-sized livestock farms to develop odor mitigation technology that is inexpensive and has low installation, operation, and maintenance costs.

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.

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 presents the primary outcomes of the neurological and emotional responses to inhalation and foot baths using the clary sage aroma. Clary sage inhalation produced varying effects on EEG (electroencephalography) depending on the concentration used, inactivating  and  waves while activating  waves, γ waves, RSMR, SEF50 and SEF90. Inhalation is more effective at enhancing individual performance and focus than promoting relaxation. The clary sage foot bath activated  waves and RSMR, while inactivating  waves, γ waves, SEF50, and SEF90. The foot bath approach has a calming impact on the mind and body, as well as reducing arousal and stress. While the advantages of clary sage inhalation and foot bath therapy are distinct, both involve the activation of RSMR, which enhances focus at work and aids in the treatment of depression and anxiety disorders. Although the emotional features of clary sage oil vary according to the dose used for inhalation, it was typically assessed as a feminine and refreshing aroma, and the clary sage foot bath was evaluated as a pleasant, invigorating, refreshing, feminine, soft, and calming fragrance. When clary sage was used in the foot bath therapy, it evoked a stronger emotional response than when it was inhaled. These findings suggest that a clary sage foot bath can be used to enhance work-related focus while also relaxing the body by activating  waves and inactivating SEF50 and SEF90.

In this review paper, the sources of odor, major odor compounds, and emission characteristics from livestock farms are summarized. The main sources of odor on livestock farms are barn facilities, manure storage facilities, manure composting facilities, and wastewater treatment facilities. High concentrations of odor are emitted during the manure removal process, and livestock odor tends to be the most severe in summer. There was a remarkable difference in odor intensity depending on the farm size and the cleaning condition, and odor intensity varied greatly depending on the weather parameters such as wind direction and speed. The concentrations of ammonia and hydrogen sulfide were high among the odor compounds emitted from livestock farms, and these compounds also contributed to odor intensity. The odor intensity in poultry and swine farms was higher than in cattle farms. Information on livestock odor emission is very useful for managing livestock odor complaints and designing odor abatement technologies.

The livestock industry continues to grow around the world, but livestock odor is becoming an environmental problem that is difficult to solve. In this review paper, the current status of the domestic livestock industry, livestock odor complaints, mediation cases involving environmental disputes related to livestock odor, livestock odor management policies and standards, livestock odor sources, major odor compounds, and emission characteristics are summarized. Domestic meat supply and meat consumption per capita are increasing, and livestock farms are becoming large-scale and intensive. Livestock odor complaints increased 4.5 times over the last five years (2014-2019), and its proportion to total odor complaints was 19%-30%. Livestock facilities larger than a certain size are classified as odor emission facilities and are managed based on the Odor Prevention Act. The information presented in this paper can be used to establish strategies to promote the sustainable development of the livestock industry while resolving air quality deterioration and public health problems caused by odor emissions from livestock farms.

Korea is a country where the population is concentrated in metropolitan areas that have undergone rapid industrial development. As of 2020, more than 43% of the total population lives in large cities, and about 18.5% of the total population lives in Seoul. A basic human need living in such a metropolis is a pleasant environment. In this study, complex odors and designated odors were evaluated at the boundary areas and at the outlets for 15 public environmental facilities selected from among odor sources in Seoul. As a result of measuring the complex odor intensity was 3 ~ 6 times at the boundary areas and 100 ~ 4,481 times at the outlets. In food waste treatment facilities, incineration facilities, and waste transfer station facilities, the compound making the largest contribution to odor is acetaldehyde, which was recorded at 46%, 25%, and 32% respectively. At a sewage treatment facility and agro-fisheries wholesale market, hydrogen sulfide was the largest contributing compound at 71% and 29% respectively.

Most of the white fumes from the tenter process of a textile plant in an industrial complex are generated by water vapor and oil mist. While general water vapor disappears when the humidity is lowered, the white fume generated in the tenter process does not disappear and is continuously maintained, resulting in environmental problems and complaints. Efforts to reduce white fume are being conducted, but it is vitally important to develop a performance index that quantitatively calculates and deduces the degree by which white fume has been reduced, so that a tangible and visible result can be obtained in the performance evaluation of prevention facilities. In this study, the removal efficiency or performance of a general wet scrubber and a wet electrostatic precipitator (electrical fume collector, EFC) installed in the actual textile tenter process was analyzed by the light scattering method that can measure the concentration of particles up to a high level. The white fume removal efficiency of the EFC was 92%, much higher than the 17% removal efficiency of the general scrubber. In addition, the EFC was more effective in removing toluene, 1,1'- [oxybis(methylene)]bis- Benzene, and benzothiazole, which are the major substances generated from the textile tenter process, as well as complex odors. From these results, it was found that the light scattering method is one of the useful tools to evaluate the performance of white fume prevention facilities in the industrial field in terms of satisfying the urgent need for measurement and the ability to obtain a clear and precise result on site. This approach is meaningful in that real-time quantification is applicable more intuitively than the gravimetric method in assessing the fume removal performance as it can be observed with the naked eye.

In this study, we evaluated the scent intensity, emotional response, and EEG response according to the concentration of bergamot scent inhaled by young women whose average age was 18, and analyzed the correlation between these factors. The correlation between bergamot concentration (P, vol %) and odor intensity (I) was [I] = 1.22 + 0.86P (r2 = 0.99). The scent intensity of bergamot was about 3.8. The emotional response to the scent of bergamot was rated as pleasant, fresh, refreshing and feminine. Inhaling bergamot decreased the α waves in the brain and increased the θ, β, and γ waves. Additionally, the edge frequencies of the SEF50 and SEF90 were increased by 0.14 Hz to 0.59 Hz and 0.75Hz to 1.26 Hz respectively by bergamot. The odor intensity (concentration) and emotional response regarding bergamot showed a weak correlation with the amount of change in the edge frequency (ΔSEF50 and ΔSEF90). These results suggest that bergamot is a refreshing, feminine fragrance with an arousing effect that activates the brain.

This study investigated the convergence of the QEEG and mood state changes in healthy females from late teens to twenties in relation to the inhalation of peppermint oil (peppermint) in different concentrations (0.1~100%). Brain activity upon stimulation by different concentrations was analyzed based on the RPVs and CVB (%), representing a rate of change compared with the background QEEG. Peppermint showed the effect of relaxation at low concentrations (0.1 and 1%) with increased θ and α waves and decreased β and γ waves. As the concentration of peppermint increases, the α wave decreases, and the θ, β and w waves increase, and there is an arousal effect. Peppermint was rated as having a refreshing, exhilarating, and intense smell. At a low concentration of 0.1%, peppermint chiefly produced a feeling of pleasantness, freshness and refreshment. However, the increase in peppermint concentration resulted in a masculine, exiting, and hard emotional response. As the concentration of peppermint increased, the odor intensity increased in a linearly. The amount of change (ΔSEF50 and ΔSEF90) in edge frequencies closely related to the activation and stress of the brain showed a positive correlation. Odor intensity has a stronger association with ΔSEF90, a stress-related brain wave indicator than with ΔSEF50, a brain activation-related indicator. In addition, both ΔSEF50 and ΔSEF90 showed a positive correlation with APIGF (feelrefreshing average preference index) and a negative correlation with APIAC (Active-Calm average preference) and APIAll (total average preference index). These findings indicate that (1) the correlation between odor intensity and stress and (2) the relationship between emotional and QEEG can be interpreted in terms of brain wave study.

A pilot-scale biocover was installed at a sanitary landfill for municipal waste, and the removal of volatile organic compounds (VOCs) by the biocover was evaluated for a long period of 550 days. The biocover (2.5 m W × 5 m L × 1 m H) was constructed with the mixture of soil, perlite, earthworm cast and compost (6:2:1:1, v/v). The total VOCs concentration of the inlet gas into the biocover was 820.3 ppb~7,217.9 ppb, and the total VOCs concentration of the outlet gas from the surface of the biocover was 12.6 ppb~1,270.1 ppb. The average removal efficiency of total VOCs was 87.6 ± 11.0% (60.5% for minimum and 98.5% for maximum). Toluene concentration was the highest among the inlet VOCs, followed by ethylbenzene, m, p-xylene and o-xylene. These aromatic VOCs accounted for more than 50% of the total VOCs concentration. Other than these aromatic VOCs, hexane, cyclohexane, heptane, benzene, and acetone were major VOCs among the inlet VOCs. Compared with the VOC profiles in the inlet gas, the relative contribution of dichloromethane to the outlet VOCs emitted from the biocover layer increased from 0.1% to 15.3%. The average removal efficiencies of BTEX in the biocover were over 84% during the operation period of 550 days. The average removal efficiencies of hexane, cyclohexane and heptane in the biocover were 86.0 ± 18.9%, 85.4 ± 20.4% and 97.1 ± 4.0%, respectively. The removal efficiency of VOCs in the biocover decreased not only when the ambient temperature had fallen below 5oC, but also when the ambient temperature had risen above 23oC. Information on the VOCs removal characteristics of the biocover installed in the landfill field can be useful for commercializing the biocover technology for the treatment of VOCs.

In this study, various conditions and phenomena that occur in the process of removing odorous VOCs by using electrolyzed oxidant were examined. The formation of hypochlorous acid, which is an oxidant produced by electrolysis, was investigated and the properties of the oxidizing agent used to decompose toluene, xylene, and cyclohexane were investigated. As a result, it was found that the production rate and the final concentration of the oxidizing agent increased with the current density. It was found that the degree of removal varies depending on the property of each pollutant. Interestingly, in the batch experiments in which the pH of the produced oxidant was controlled, it was found that the degree of elimination varied depending on the pH of the substance. These results suggest that the difference in the concentration and distribution of hypochlorous acid (HOCl) and hypochlorite (OCl−) due to the pH change leads to the difference in oxidizing power on the oxidation characteristics of each substance. Styrene and terpineol showed better degradation characteristics than toluene and xylene in odorous VOC removal experiments by spraying electrolytic oxidant using a lab-scale continuous reactor. In conclusion, the removal of odorous VOCs by the electrolytic oxidant can have various applications in that it can oxidize pollutants of various spectra.

To analyze the synergistic effects of applying lavender aroma to a footbath, we analyzed the EEG and emotional responses of footbath, lavender inhalation, and lavender footbath in women in their 30s. Foot baths reduced wave activation, wave and wave inactivation, and SEF50 and SEF90. The foot bath activated waves by about 66% compared to the background EEG, and reduced SEF50 and SEF90 by 0.43 Hz-0.68 Hz and 3.7 Hz, respectively. Lavender inhalation activated α, β, and γ waves at a concentration of 1% or more, and inactivated θ waves. As the concentration of lavender inhalation increased, α waves increased and β and γ waves decreased. Lavender foot bath activates θ waves and α waves, and inactivates β waves and γ waves. Compared with the background EEG, the lavender foot baths reduced SEF50 and SEF90, which are the median frequencies of EEG power, 0.5 Hz and 3.4 Hz, respectively. Lavender showed a positive emotional response when applied to inhalation and foot bath. Lavender showed a positive emotional response when applied to inhalation and foot bath. When the lavender was inhaled at the concentration of 1~10% and the lavender foot bath was applied, the average preference index (API) showed 0.64~0.66 and 3.6 ± 0.6, respectively. Lavender oil has a greater synergistic effect on emotional reactions when applied to an aromatherapy bath than by inhalation. Lavender decreased SEF50 and SEF90 as the API increased. A lavender footbath was superior to lavender inhalation in both emotional and EEG responses, and was more relaxed and calming than a footbath. These results suggest that the aroma foot bath method, in which lavender is applied to a footbath, is more effective in terms of providing relaxation and calming than a footbath or lavender inhalation aromatherapy.

건강 식품인 병아리콩을 화장품의 원료로 활용하기 위하여 Bacillus subtilis Natto 균주로 병아리콩을 발효한 낫토를 마스크 팩에 적용하여 피부개선 효과를 연구하였다. 병아리콩 낫토를 동결건조하여 얻은 분말을 paste 제형으로 얼굴 마사지 팩에 적용하였다. 50~60대 여성을 대상으로 낫토 팩의 피부개선 효과를 조사하였다. 낫토 팩의 처치 횟수가 증가함에 따라 피부가 개선되며 4회 처치 후 개선 효과가 두드러졌다. 4회 처치 후 수분 함량과 피지 분비량이 각각 8.4±3.6%p와 4.0±2.3%p 증가하였고, 피부 모공과 주름도 각각 1.8±0.3%p와 1.8±0.9%p 감소하였다. 피부 색소침착은 1.3±0.2%p 감소 되었고, 피부 톤은 55.2%에서 55.9%로 0.7±0.2%p 밝아졌다. 병아리콩을 발효하여 얻은 낫토 발효물이 보습, 모공, 주름, 색소침착, 피지분비, 피부톤 등의 피부개선 효과가 있으며, 다양한 기능성 화장품의 원료로 활용 가능성을 확인하였다.

본 연구에서는 임상시험의 대체시험법으로 시편을 이용한 화장품의 보습능 평가기법을 연구 하였다. 4종의 시편(일본떡, 가래떡, 밀가루, 한천)에 대한 립 메이크업 제품의 발림성, 표면의 건조 특성, 수분손실율 등을 비교 평가하였다. 또한, 10종의 립 메이크업 제품(립스틱 5종, 립밤 3종, 립글로스 2종)을 대상으로 시편을 사용한 수분손실율과 임상평가를 통한 경피수분손실량을 분석하고 이들의 상관 관계를 조사하였다. 시편의 수분손실율은 한천 > 가래떡 > 일본떡 > 밀가루 순으로 한천시편의 수분 손실율(수분증발 민감도)이 가장 우수하였다. 또한, 시편소재 중 한천시편이 발림성, 표면 균열, 원료 수급 등의 측면에서 가장 적합하였다. 한천시편은 볼록하고 매끄러운 표면의 시편 제조가 가능한 열 전달이 낮은 플라스틱재질의 용기가 적합하였다. 한천시편을 이용한 립메이크업 제품군에 대한 수분손실율(보습능)과 임상시험법(경피수분손실)과 강한 상관관계를 보였다. 이러한 결과들은 본 연구에서 제안한 한천 시편을 이용한 보습능 평가 기법이 유용한 대체시험법 중 하나로 활용 가능함을 의미한다.

The purpose of this study is to investigate the effects of oxides (caryophyllene oxide, eucalyptol and linalool oxide), one of the major ingredients of essential oils, on odor intensity, electroencephalography (EEG) response and emotional response. The subjects were women in their twenties. Inhalation concentrations of oxides were varied from 0.01 to 10%, and EEGs were collected by Quantitative EEG. The odor intensity and average preference index (API) of the oxides were ranked in the order of eucalyptol > linalool oxide > caryophyllene oxide. Eucalyptol is a refreshing and pleasant substance that activates the brain (activation of β and γ waves and spectral edge frequencies (SEF50 and SEF90)). Linalool oxide has a calm and soft substance (activation of θ, inactivation of α, β, and γ waves) at a low concentration (<0.1%), and a fresh smell at high concentration (inactivation β and activation of θ and γ). Caryophyllene oxides were evaluated as a substance that is comfortable, soft, calm and sedating, which deactivates the brain (activation of α, inactivation of β and γ). Oxide materials showed a positive correlation between the odor intensity and the SEFs. Each of the oxides showed unique characteristics in the areas of odor intensity, emotional response, API, and EEG. These results give us a better understanding of the properties of the pure materials that make up a fragrance, and provide useful information for the manufacture of fragrance products or aroma oil blends with enhanced specific functions.

Seasonal emission characteristics of odors and methane were investigated throughout the period of 17 months in which the emission status of odors and methane from soil cover layers in a sanitary landfill was measured. Complex odor emitted from soil cover layers fluctuated largely at the range of 7~20,800 OU (Odor Unit) in odor dilution ratio, and the median and average values were 2,080 and 4,203 OU, respectively. The intensity of complex odor showed higher values in the spring (5,663 ± 4,033 OU) and winter (6,056 ± 8,372 OU) than in the summer (1,698 ± 3,676 OU) and fall (1,761 ± 451 OU). Based on average concentrations, the compounds with high contribution values for the sum of the odor quotient (SOQ) were hydrogen sulfide (46.1%), methyl mercaptan (26.4%), and dimethyl sulfide (16.8%). This result shows that sulfur compounds were the main odor-causing compounds in the target landfill. The flux of complex odor was 0.17~70.36 OU·m−2·min−1 (Median 0.47, Average 5.40), and the flux of hydrogen sulfide was 0~114.70 μg·m−2·min−1 (Median 0.13, Average 5.91). The methane flux was 0.59~312.70 mg-CH4·m−2·min−1 (Median 25.61, Average 47.99). The methane concentrations emitted at the soil cover layers showed the highest values of 1.0~62.5% (Median 33.0, Average 21.1) in the spring, and the lowest values of 0.1~11.7% (Median 2.3, Average 3.7) in the winter. The methane concentrations in the summer and fall were similar with the average of 17.9% (range of 0.2-44.2%) and 12.5% (range of 2.2-42.5%), respectively. The emission data of odors and methane from soil cover layers can be utilized to establish management policy and apply mitigation technologies for the control of odor and greenhouse gases emitted in landfills.

In this study, the behavior of dominant microbial communities was investigated in the treatment of porcine carcasses using an anaerobic high temperature burial composting method. The correlation between odor emission and bacterial community structure was analyzed through principal component analysis and extended local similarity analysis. In the burial layer of porcine carcass, the dominant bacteria were Bacillaceae (46%), Thermoactinomycetaceae (15%) and Lactobacillaceae (4%) in the early stage and Bacillaceae (46%), Thermoactinomycetaceae (15%), Lactobacillaceae (4%) in the end. Clostridiaceae (CH3SH), Bacillacea ((CH3)2S2), Clostridium ((CH3)2S2), Clostridial (H2S), Oceanobacillus (H2S), and Thermoanaerobacteraceae (H2S) were closely related to the sulfurous odorants, which are the highest odor contributions. The emission of sulfurous odor substances such as H2S, CH3SH, (CH3)2S, and (CH3)2S2 showed a positive correlation with each other, but showed a negative correlation with nitrogenous odorants (NH3 and TMA), aldehydes, organic acids, and VOCs. The results of this correlation analysis can provide useful information that enables us to understand the characteristics of microbial communities and odor generation during the degradation of carcasses and to manage odors and burial sites in the treatment of carcass.

It is very important to treat infected livestock carcasses safely and quickly. In this study, the degradation characteristics and odor generation characteristics of carcasses were investigated during the treatment of swine carcasses using the anaerobic burial composting method. While the carcasses were decomposed, the temperature remained high, at 40~55°C on average, and most of the carcasses were decomposed rapidly. The major odorcontributing substances in the buried composting method are sulfuric odor substances such as H2S, CH3SH, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), and the odor contribution of these substances is 93~99%. Among them, CH3SH, which accounts for about 56~89% of odor contribution, was the most representative indicator substance. Despite the anaerobic digestion process, the methane concentration in the digestion process was as low as 0.5~0.8% at the burial point of the carcass. The odor and methane produced during the decomposition of the carcasses decreased considerably during the discharge to the surface layer through the buried layer consisting of compost. These results suggest that anaerobic high temperature burial composting is one of the most useful methods to treat carcasses of infected livestock.

In order to reduce odor and methane emission from the landfill, open biocovers and a closed biofilter were applied to the landfill site. Three biocovers and the biofilter are suitable for relatively small-sized landfills with facilities that cannot resource methane into recovery due to small volumes of methane emission. Biocover-1 consists only of the soil of the landfill site while biocover-2 is mixed with the earthworm casts and artificial soil (perlite). The biofilter formed a bio-layer by adding mixed food waste compost as packing material of biocover-2. The removal efficiency decreased over time on biocover-1. However, biocover-2 and the biofilter showed stable odor removal efficiency. The rates of methane removal efficiency were in order of biofilter (94.9%)>, biocover-1(42.3%)>, and biocover-2 (37.0%). The methane removal efficiency over time in biocover-1 was gradually decreased. However, drastic efficiency decline was observed in biocover-2 due to the hardening process. As a result of overturning the surface soil where the hardening process was observed, methane removal efficiency increased again. The biofilter showed stable methane removal efficiency without degradation. The estimate methane oxidation rate in biocover- 1 was an average of 10.4%. Biocover-2 showed an efficiency of 46.3% after 25 days of forming biocover. However, due to hardening process efficiency dropped to 4.6%. After overturn of the surface soil, the rate subsequently increased to 17.9%, with an evaluated average of 12.5%.