• 한국축산시설환경학회지
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• 제17권3호
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• pp.197-204
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• 2011

돈 분뇨 슬러리를 대상으로 하여 기계적 분쇄와 캐비테이션 그리고 오존을 적용하여 원료의 특성 변화와 생분해도 그리고 메탄 생성잠재성 변화를 측정한 시험결과를 요약한 주요 내용은 다음과 같다. 1. 분쇄방법과 캐비테이션의 방법의 경우 큰 입자 및 미세입자를 줄일 수 있는 효과가 있었다. 2. 오존처리의 방법의 경우 용존물질의 부분산화, 미세입자의 부분산화 및 가용화 촉진을 통해 혐기성 소화의 첫 단계인 가수분해를 더욱 촉진할 것으로 사료된다. 3. 입도분포 변화에 따른 메탄생성량의 변화는 분쇄처리할 경우가 캐비테이션과 오존 처리방법에 비해 더 양호한 메탄생성효율을 보였다.

• 한국해양환경ㆍ에너지학회지
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• 제9권3호
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• pp.154-159
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• 2006

본 연구에서는 생선폐기물의 혐기성 소화처리를 위한 생선폐기물의 혐기성 생분해 특성을 평가하기 위해 serum bottle을 이용한 BMP(Biochemical Methane Potential) test를 수행하였다. 어판장에서 배출되는 생선폐기물 중 고등어 손질 시 발생되는 폐기물 중 내장을 제외한 부분과 갈치손질 시 발생되는 폐기물 중 내장을 제외한 부분, 생선손질 시 발생되는 내장류 3개 군을 실험대상 기질로 선정하여 사용하였다. 각각의 생선폐기물들을 분쇄 후 serum bottle에 11 50 ml, 100 ml, 150 ml씩 혐기적으로 넣은 다음 BMP test를 실시하였으며 실험의 정확도를 위하여 동일 시료에 대하여 3개씩 중복으로 조제하여 실험하였다. 배양시간에 따른 누적 메탄가스 생성량과 메탄생성속도를 평가하였다. 이들 값들은 기질의 특성에 따라 다르기는 하나 통상 휘발성 고형물 (Volatiles Solids: VS) 1 kg당 420-470 ml의 메탄가스를 생성하는 것으로 나타났다. 기질 종류별로 볼 경우 갈치와 고등어군에 비하여 내장 군이 고형물 단위 중량당 메탄발생량과 분해속도 측면에서 모두 높은 것으로 나타났다. 대상 시료에 대해 원소분석을 실시한 결과, C/N비는 5.2로 나타났다. 원소분석 자료를 근거로 계산한 이론적인 최종 메탄생성량은 $522ml{\cdot}CH_4/g{\cdot}VS$로 나타났다. 이를 본 실험에서 구한 실제 최종 메탄생성량과 비교해 볼 때 생분해도는 0.847로 평가되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제27권4호
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• pp.600-607
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• 2014

The aim of this study was to assess the effect of substrate to inoculum ratio (S/I ratio) on the biochemical methane potential (BMP) and anaerobic biodegradability ($D_{deg}$) of different piggery slaughterhouse wastes, such as piggery blood, intestine residue, and digestive tract content. These wastes were sampled from a piggery slaughterhouse located in Kimje, South Korea. Cumulative methane production curves for the wastes were obtained from the anaerobic batch fermentation having different S/I ratios of 0.1, 0.5, 1.0, and 1.5. BMP and anaerobic biodegradabilities ($D_{deg}$) of the wastes were calculated from cumulative methane production data for the tested conditions. At the lowest S/I ration of 0.1, BMPs of piggery blood, intestine residue, and digestive tract content were determined to be 0.799, 0.848, and $1.076Nm^3kg^{-1}-VS_{added}$, respectively, which were above the theoretical methane potentials of 0.539, 0.644, and $0.517Nm^3kg^{-1}-VS_{added}$ for blood, intestine residue, and digestive tract content, respectively. However, BMPs obtained from the higher S/I ratios of 0.5, 1.0, and 1.5 were within the theoretical range for all three types of waste and were not significantly different for the different S/I ratios tested. Anaerobic biodegradabilities calculated from BMP data showed a similar tendency. These results imply that, for BMP assay in an anaerobic reactor, the S/I ratio of anaerobic reactor should be above 0.1 and the inoculum should be sufficiently stabilized to avoid further degradation during the assay.

• 상하수도학회지
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• 제37권5호
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• pp.253-259
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• 2023

Bioreactors are devices used by sewage treatment plants to process sewage and which produce active sludge, and sediments separated by solid-liquid are treated in anaerobic digestion tanks. In anaerobic digestion tanks, the volume of active sludge deposits is reduced and biogas is produced. After dehydrating the digestive sludge generated after anaerobic digestion, anaerobic digested wastewater, which features a high concentration of organic matters, is generated. In this study, the decomposition of organic carbon and nitrogen was studied by advanced oxidation process. Ozone-microbubble flotation process was used for oxidation pretreatment. During ozonation, the TOC decreased by 11.6%. After ozone treatment, the TOC decreased and the removal rate reached 80.4% as a result of the Ultra Violet-Advanced Oxidation Process (UV-AOP). The results with regard to organic substances before and after treatment differed depending on the organic carbon index, such as CODMn, CODCr, and TOC. Those indexes did not change significantly in ozone treatment, but decreased significantly after the UV-AOP process as the linkage treatment, and were removed by up to 39.1%, 15.2%, and 80.4%, respectively. It was confirmed that biodegradability was improved according to the ratio of CODMn to TOC. As for the nitrogen component, the ammonia nitrogen component showed a level of 3.2×10² mg/L or more, and the content was maintained at 80% even after treatment. Since most of the contaminants are removed from the treated water and its transparency is high, this water can be utilized as a resource that contains high concentrations of nitrogen.

• Environmental Engineering Research
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• 제16권2호
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• pp.103-109
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• 2011

This work experimentally determined the effect of thermal and microwave pretreatments on the anaerobic digestion of mixtures of municipal primary and secondary sludges in semi-continuous mesophilic digesters at hydraulic retention times (HRT) of 20, 15, 10, 7, and 5 days. The ratio of soluble chemical oxygen demand (COD) to total COD in thermally pretreated and microwaved sludges at $80^{\circ}C$ was 2.7 and 3.2 times higher than that of raw sludge, respectively. The volatile solids (VS) and COD removal efficiencies in all three digesters fed with raw (control), thermally pretreated (TM), and microwaved (MW) sludges decreased as the HRT was reduced. The highest relative improvement in VS removal compared to the control occurred at the HRT of 5 days in the TM and MW (29 and 41% higher than the control, respectively). At this HRT, improvement in the COD removal efficiencies in the TM and MW compared to the control was 28 and 53%, respectively. Improvements in biogas production compared with the control increased in both the TM and MW as the HRT was reduced to 5 days. The relative improvement in daily biogas production compared to the control from the TM and MW was 33 and 53% higher than the control at the HRT of 5 days, respectively. The results show that microwave pretreatment is more effective than thermal pretreatment in increasing the solubilization degree and mesophilic anaerobic biodegradability of sewage sludge.

• 한국토양비료학회지
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• 제48권5호
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• pp.542-548
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• 2015

This study investigated methane productions and a degradation rate of organic matters by German standard method, VDI4630 test. In this study, 4 livestock byproducts from livestock farm were selected for the investigation. The objective of this study was to estimate a distribution of organic matters by using the double first-order kinetics model in order to calculate the rate of biodegradable organic matters which degrade rapidly in the initial stage and the persistently biodegradable organic matters which degrade slowly later. As a result, all the byproducts applied in this study showed rapid decomposition in the initial stage. Then the decomposition rate began to slow down for a certain period and the rate became 5 times slower than the initial decomposition rate. This trend of decomposition rate changes is typical conditions of organic matter decompositions. The easily degradable factors ($k_1$) ranged between $0.145{\sim}0.257day^{-1}$ and persistent degradable factors ($k_2$) were $0.027{\sim}0.080day^{-1}$. Among these results, greater organic matter decomposition rates from VDI4630 had greater $k_1$ values (0.257, $0.211day^{-1}$) and smaller $k_2$ values (0.027, $0.030day^{-1}$) for dairy wastewater and forage byproduct, respectively.

• 유기물자원화
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• 제31권1호
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• pp.27-34
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• 2023

본 연구에서는 버섯 폐배지의 혐기성소화 효율 향상을 위해 수열전처리를 실시하고, 리그노셀룰로오스계 물질의 고온 가수분해 과정에서 생성될 수 있는 중간산물이 기질의 생분해도와 바이오가스 전환 효율에 미치는 영향을 함께 판단하였다. 수열전처리 온도의 범위를 150, 180, 210℃로 설정하였으며, 모든 수열전처리 온도에서 기질의 가용화율이 향상되는 결과를 확인할 수 있었다. 추가적으로, 150℃로 버섯 폐배지를 전처리한 경우에는 혐기성소화 효율에 영향을 미칠 수 있는 C/N 비가 개선되는 효과를 함께 확인하였다. 다만 전처리 온도가 180, 210℃인 경우에는 오히려 150℃로 전처리를 수행한 경우에 비해 메탄 생성량이 저하되는 경향을 보였는데, 이는 리그노셀룰로오스 물질의 중간분해 산물인 퓨란유도체의 형성으로 인해 메탄생성균이 영향을 받은 것으로 판단된다. 결국, 수열전처리를 통해 리그노셀룰로오스계 바이오매스의 가용화율 향상을 통한 메탄 생성 향상을 기대할 수 있으나, 혐기성소화 효율을 저해할 수 있는 중간산물이 생성되지 않는 적정 전처리 온도의 확인과 적용이 중요할 것으로 판단된다.

• 한국환경농학회지
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• 제35권2호
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• pp.121-127
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• 2016

BACKGROUND: Anaerobic digestion is the most feasible technology because not only the energy embedded in organic matters can be recovered, but also they are stabilized while being degraded. This study carried out to improve methane yield of slaughterhouse wastewater treatment sludge cake by the thermal pre-treatment prior to anaerobic digestion.METHODS AND RESULTS: Slaughterhouse wastewater treatment sludge cake was pre-treated by the closed hydrothermal reactor at reaction temperature of 190℃. BMPs (Biochemical methane potential) of the thermal hydrolysate was tested in the different S(Substrate)/I(Inoculum) ratio conditions. COD(Chemical oxygen demand) and SCOD(Soluble chemical oxygen demand) contents of thermal hydrolysate were 10.99% and 10.55%, respectively, then, the 96.00% of COD was remained as a soluble form. The theoretical methane potential of thermal hydrolysate was 0.51 Nm³ kg^-1-VS_added. And BMPs were decreased from 0.56 to 0.22 Nm³ kg^-1-VS_added when S/I ratio were increased from 0.1 to 2.0 in the VS content basis. Those were decreased from 0.32 to 0.13 Nm³ kg^-1-COD_added when S/I ratio were increased from 0.1 to 2.0 based on COD content. The anaerobic degradability of VS basis have showed 196.9%, 102.2%, 80.7%, 67.4%, and 39.4% in S/I ratios of 0.1, 0.3, 0.5, 1.0, and 2.0, respectively. Also the COD of 119.6%, 76.3%, 70.1%, 69.0%, and 43.1% were degraded anaerobically in S/I ratios of 0.1, 0.3, 0.5, 1.0, and 2.0, respectively.CONCLUSION: BMPs obtained in the S/I ratios of 0.1 and 0.3 was overestimated by the residual organic matters remaining at the inoculum. And inhibitory effect was observed in the highest S/I ratio of 2.0. The optimum S/I ratios giving reasonable BMPs might be in the range of 0.5 and 1.0 in S/I ratio. Therefore VS biodegradability of thermal hydrolysate was in 67.4-80.7% and COD biodegradability showed 69.0-70.1%.

• 대한환경공학회지
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• 제37권10호
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• pp.583-589
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• 2015

본 연구에서는 슬러지 케이크를 열수분해한 탈리액을 대상으로 혐기소화특성을 평가하였으며, 슬러지 탈수케이크의 열수분해후 성상변화 및 열수분해 탈리액의 MAP결정화, MAP결정화 상등액을 이용한 혐기소화공정효율을 고찰하였다. 탈리액의 MAP결정화는 Mg:P의 비가 1.5:1, pH가 9.5인 조건이 최적이었으며, 이때 MAP생성으로 인해 열수분해 탈리액의 암모니아성 질소는 50%, 인산염은 97%가 제거되어 열수분해 탈리액의 혐기소화 전처리 시 효과적임을 알 수 있었다. 기질 대 미생물비(S/I) 0.5 조건에서 중온 회분식 혐기소화조 운전결과 MAP 결정화를 거친 열수분해 탈리액의 최종생분해도는 63%였으며, 분해속도상수 $k_1$은 $0.207day^{-1}$로 17일 동안 이분해성 기질비율($S_1$)이 90% 분해되었고, 나머지 10% ($S_2$)는 $k_2$ ($0.024day^{-1}$)의 느린 속도로 분해되어 열수분해로 인해 슬러지의 생분해성이 높아짐을 알 수 있다. 열수분해 탈리액을 MAP결정화한 후, 탈리액을 대상으로 SCFMR형태의 혐기조를 운전한 결과 HRT 20일(OLR 1.43 g VS/L-d)에서 평균 0.45 v/v-d의 Biogas가 발생하였으며, TVS제거효율은 37~41% 범위로 우수한 혐기소화효율을 나타내었다.

• 상하수도학회지
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• 제21권3호
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• pp.331-339
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• 2007

The purpose of this study was to investigate the biodegradability and performance of organic removal and methane production rate when treating piggery wastewater using a pilot scale two-phase anaerobic system operated up to a volumetric rate of $10m^3/day$. The pilot scale two-phase anaerobic process is consisted of a continuous-flow stirred-tank reactor (CFSTR) for the acidification phase and an Upflow Anaerobic Sludge Blanket reactor (UASB) for the methanogenesis. The acidogenic reactor played key roles in reducing the periodically applied shock-loading and in the acidification of the influent organics. The acidogenic CFSTR was operated at organic loading rates (OLR) between 1.8 and $14.4kgCOD/m^3{\cdot}day$, and the UASB reactor was operated between 0.5 and $5.6kgCOD/m^3{\cdot}day$. A stable maximum biogas production rate was $81m^3/day$ and the methane conversion rate of the organic matter varied from 0.30 to $0.42L\;CH_4/g\;COD_{removed}$(0.40) at hydraulic retention time (HRT) above 3.5days. The methane contents ranged from 73 to 82% during the experimental period. It is known that most of the removed organic matter was converted to methane gas, and the produced biogas might be high quality for its subsequent use.