In this study, we analyzed the changes in concentrations of volatile fatty acids (VFA), phenols, and indoles, as well as odor contribution in pig slurry. The pig slurry was stored for approximately two months after the manure excretion of pigs which had been fed 3% level of peat moss additive. The investigation was carried out through lab-scale experiments simulating slurry pit conditions within pig house. Throughout the storage period, the concentration of VFA exhibited a tendency to be 11%-32% higher in the pig manure treated with peat moss as compared to the control group. From a concentration perspective, phenol and acetic acid accounted for the majority of the total odor compounds produced during the pig slurry storage period. However, their significance diminished when the concentration of odoros compounds are converted into odor activity value and odor contribution. Despite the odor reduction effect of the ammonia (NH3) adsorption by peat moss, if it cannot effectively reduce the high odor-contributing compounds such as indoles and p-cresol, the sole use of peat moss may not be considered an effective means of mitigating odors produced by pig slurry. According to this study, indoles, p-cresol, skatole, and valeric acid were consistently revealed as major odor-contributing substances during the two-month storage of pig slurry. Therefore, a comprehensive odor mitigation methodology should be proposed, taking into consideration the odor generation characteristics (including temporal concentration and odor contribution) of pig slurry-derived odors during storage.

Public complaints arising from centralized animal manure treatment plants are increasing due to the odors produced during animal manure treatment. Various physico chemical and biological methods are used to mitigate such odors. Still, many problems exist, such as a lack of fundamental data on odor generation characteristics and design standards for odor mitigation facilities. Therefore, this study evaluated the characteristics of NH3 and H2S gas produced from a centralized animal manure treatment plant. The centralized animal manure treatment plant selected in this study has a treatment capacity of 150 tons (animal manure and food waste) per day. The composting matrix was mechanically turned from 9:00 am to 6:00 pm on weekdays and not turned all day on weekends. The NH3 concentrations measured during the day on weekdays (96.4 ± 7.8 ppmv) were about 14% higher than on weekends (84.9 ± 15.9 ppmv). During the week, the ammonia concentration during the day was about 15% higher than at night, but there was no difference between day and night on weekends. The hydrogen sulfide concentration during the day (4,729 ± 3,687 ppbv) on a weekday was about 4.7 times higher than at night (1,007 ± 466 ppbv). The results of this study provide valuable information that is necessary for the operation of odor mitigation facilities. It is expected that the results will contribute to establishing an operational strategy that can reduce the energy required to collect exhaust gas.

This study evaluated the odor mitigation effect of rice husk biochar addition to the bedded pack dairy barn floor using lab-scale reactors for five days. Rice husk biochar mixed with dairy manure and sawdust mixture at different ratios (5%-addition test unit: adding biochar by 5% of the total solid weight of the mixture, 10%-addition test unit: adding biochar by 10% of the total solid weight of the mixture). Cumulative NH3 and H2S emissions of 10%-addition test unit were reduced by 26% (p< 0.05) and 46% (p = 0.0655), respectively, compared with control. However, 5%-addition test unit did not show NH3 and H2S emission reduction. Further research is needed to determine the appropriate level of biochar addition between 5 and 10%, and to evaluate applicability in the field through economic analysis.

This study was conducted to figure out the productivity of Italian ryegrass(IRG) and leaching water characteristics based on horse manure compost level in Jeju. This study was conducted for about six months. Six treatments were established : non-fertilizer(NF), chemical fertilizer 100%(CF), horse manure compost 50% and chemical fertilizer 50% combination(Combination), horse manure compost with 50% of nitrogen (50%), 100% of nitrogen(100%), 150% of nitrogen(150%). The highest amount of dry matter yield of IRG was revealed in CF(11,965± 564 kg/ha), and both 150% and Combination were second(p<0.05). Nitrate leaching tended to increase until the third analysis and then decreased. There were not significantly differences among mean nitrate concentrations. The findings of the study suggest that horse manure compost with 50% of nitrogen be applied for IRG as basal fertilization and then 50% of chemical fertilizer be applied as top fertilization.

Efforts were made to identify the optimum operational condition of Semi-continuously Fed and Mixed Reactor (SCFMR) to treat the dairy cow manure and saw dust mixture. Step-wise increase in organic loading rates (OLRs) and decrease in hydraulic retention times (HRTs) were utilized until the biogas volume became significantly decreased in SCFMR at mesophilic temperature (35oC). The optimum operating condition of the SCFMR fed with TS 15% dairy cow manure and saw dust mixture was found to be at HRTs of 30 ~ 35 days and its corresponding OLRs of 3.5 ~ 4.3 kgVS/ m3-day. The optimum ranges of biogas and methane production rates were 1.36 ~ 1.47 volume of biogas per volume of reactor per day (v/v-d) and 1.0 ~ 1.14 v/v-d, respectively. This result was due to the high alkalinity concentration of SCFMR fed with the original substrate, dairy cow manure and saw dust mixture whose alkalinity was more than 10,000 mg/L as CaCO3. The parameters for the reactor stability, the ratios of volatile acids and alkalinity concentrations (V/A) and the ratio of propionic acid and acetic acid concentrations (P/A) appeared to be 0.07 ~ 0.09 and 0.38 ~ 0.43, respectively, that were greatly stable in operation. The Total Volatile Solids (TVS) removal efficiency based on the biogas production was 39 ~ 45% at the optimum HRTs. Free ammonia toxicity was not experienced at above 160mg/L due to the acclimation of high concentration of ammonia by the high reactor TS content above 9.0%.

Anaerobic mesophilic batch tests of dairy cow manure, dairy cow manure/saw dust mixture and dairy cow manure/ rice hull mixtures collected from bedded pack barn were carried out to evaluate their ultimate biodegradability and two distinctive decay rates (k1 and k2) with their corresponding degradable substrate fractions (S1 and S2). Each 3 liter batch reactor was operated for more than 100 days at substrate to inoculum ratio (S/I) of 1.0 as an initial total volatile solids (TVS) mass basis. Ultimate biodegradabilities of 37 ~ 46% for dairy cow manure, 32 ~ 40% for dairy manure/saw dust mixture and 31 ~ 38% for dairy cow manure/rice hull mixture were obtained respectively. The readily biodegradable fraction of 90% (S1) of dairy manure BVS (So) degraded with in the initial 29 days with arange of k1 of 0.074 day−1, where as the rest slowly biodegradable fraction (S2) of BVS degraded for more than 100 days with the long term batch reaction rate of 0.004 day−1. For the dairy manure/saw dust mixture and dairy manure/rice hull mixture, their readily biodegradable portions (S1) appeared 71% and 76%, which degrades with k1 of 0.053 day−1 and 0.047 day−1 for an initial 30 days and 38 days, respectively. Their corresponding long term batch reaction rates were 0.03 day−1.

고유가 및 국제적 환경규제 강화와 더불어 우리나라는 2013년 온실가스 감축 의무대상국으로의 편입이 가시화되고 있다. 따라서 농업분야의 신재생에너지 사업기반 마련을 위해 가축분뇨를 비롯한 농축산바이오매스의 혐기성소화 방식을 통한 바이오가스 생산 및 에너지화 기술 개발의 필요성이 증대되고 있다. 또한 농업부문의 급속한 시장개방으로 외국산 축산물의 수입이 본격화됨에 따라 국내 축산업의 경쟁력 제고와 축산업 과정에서 필연적으로 발생하는 가축분뇨의 해양배출 금지에 대비한 육상처리시설 기반 확보가 필요하다. 가축분뇨 및 농축산바이오매스의 혐기성소화 기술 적용은 장래 해양배출 금지에 따른 처리시설 기반확보와 동시에 온실가스를 저감하는 환경적 기능, 메탄가스와 같은 재생에너지 생산 그리고 소화슬러지는 퇴･액비화 후 양질의 유기질 비료로 활용하는 등 자원순환 기능을 동시에 달성할 수 있다. 이에 본 연구에서는 다양한 가축분뇨 및 농축산 바이오매스를 대상으로 회분식 혐기성소화 실험을 통해 각 연구대상 통합시료의 분해속도 및 생분해 특성을 평가하고, 가축분뇨 및 농축산바이오매스의 혐기성통합소화 플랜트 설계 기초자료를 제시하고자 하였다. 혐기성 통합 소화 대상 농축산바이오매스는 동계사료작물 청보리, 하계사료작물 사료용 옥수수, 가축분뇨는 우분을 연구대상으로 하였다. 가축분뇨와 Energy Crop의 혼합비는 VS기준으로 60 : 40이었으며, 식종균은 D시의 하수처리장의 중온혐기성소화균을 채취하여 순응적응시켜 이용하였다. 최종생분해도평가는 Graphical Statistic Analysis Method와 BMP Test를 적용하였다. 실험기간 120일동안 우분의 최종생분해도는 72~73%이었으며 가축분뇨와 사료작물의 혼합비 60:40 조건에서 우분+옥수수 통합시료는 83~85%, 우분+청보리 통합시료는 80%의 최종생분해도를 나타내었다. 우분의 전체 생분해성 유기물 중 빠르게 분해되는 분율(S1)은 78%으로 k1(0.087day-1)의 속도로 25일 안에 빠르게 분해하였으며, 느리게 분해되는 S2 분율은 22%로써 k2(0.004day-1)의 속도로 95일의 긴 시간동안 분해하였다. 우분+사료용 옥수수 통합시료(혼합비 60:40)의 S1은 25일 동안 BVS 중 80%가 0.090day-1(k1)의 속도로 빠르게 분해하였으며, S2는 95일 동안 k2, 0.004day-1의 속도로 BVS의 20%가 분해되었다. 우분+청보리 통합시료(혼합비 60:40)의 S1은 30일 동안 BVS 중 76%가 0.069day-1(k1)의 속도로 빠르게 분해하였으며, S2는 90일 동안 k2, 0.009day-1의 속도로 BVS의 24%가 분해되었다.