• 유기물자원화
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• 제13권3호
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• pp.51-62
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• 2005

본 실험은 음식물 쓰레기와 다른 유기성 자원의 혼합처리가 지렁이(Eisenia foetida)의 생육과 분변토 생산량, 분변토의 화학적 특성에 미치는 영향을 조사하여 지렁이에 의한 음식물쓰레기의 처리 가능성을 조사하였다. 음식물 쓰레기 100%, 음식물 쓰레기와 우분, 돈분 슬러지, 톱밥발효 돈분, 인분 슬러지, 하수 슬러지를 각각 50:50으로 혼합 처리하였을 때, 음식물쓰레기 100% 처리구에서는 지렁이가 생존하지 못하여 지렁이에 의한 퇴비화가 불가능하였다. 지렁이에 의한 퇴비화 과정에서 최종산물로 생산되는 분변토는 모든 처리구에서 유효인산 함량, 양분 보전능(CEC), 친환성 칼륨 및 마그네슘이 함량이 식물체의 생육에 필요한 양분요구량 이상 함유되었다. 분변토 생산량은 음식물 쓰레기와 톱밥발효 돈분의 혼합 처리구에서 가장 많았고, 분변토 비율은 음식물 쓰레기와 우분의 혼합 처리구에서 유의하게 높았다. 또한 지렁이 체 조직으로의 유기물 전환율과 전환효율은 음식물 쓰레기와 우분, 음식물 쓰레기와 톱밥발효 돈분 처리구에서 높은 값을 나타내어, 음식물 쓰레기와 가축 분을 혼합 처리하는 것이 지렁이에 의한 퇴비화에 가장 알맞은 먹이조건인 것으로 판단되었다.

• 한국물환경학회지
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• 제20권6호
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• pp.583-588
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• 2004

This research examined the treatment efficiency and methane production rate in treating slurry-type swine waste using UASB (upflow anaerobic sludge blanket) reactor. The UASB reactor was operated at an organics volumetric loading rate (VLR) of $2.6-15.7kgCOD/m^3/day$. A stepwise increase of the VLR resulted in a temporary deterioration in the COD removal rate in UASB reactor but recovered quickly. The COD removal rate were 65-70% for VLR up to $5 kgCOD/m^3/day$. When organics VLR was $10kgCOD/m^3/day$, the COD removal rate decreased sharply and there was loss of 17.537g of the seeding biomass due to sludge washout. This result indicated that the UASB system cannot be adapted to more than $10kgCOD/m^3/day$ of VLR. As the organic load increased from 2.6 to $15.7kgCOD/m^3/d$, the biogas production rate varied from 3.2 to 10.8 L/d and the methane conversion rate of the organic matter varied from 0.30 to $0.23m^3CH_4/kg\;COD_{removed}$. The methane content showed the range of 70.1-81.5% during the experimental period. The volatile solids (VS) removal efficiency was similar at the low VLR (< $5 kgCOD/m^3/day$), but it decreased sharply at the high VLR (> $5 kgCOD/m^3/day$). The VS reduction rate was, moreover, large those of COD. The result shows that hydraulic retention time above 2 days is essential in case of treating wastewater containing 1% of solids.

• 한국유기농업학회지
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• 제20권3호
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• pp.369-383
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• 2012

사육밀도를 달리 했을 때 지렁이 개체군의 생체량 증가를 위한 최적 사육밀도를 추정하려고 하였다. 실험결과를 요약하면 다음과 같다. 1. 사육밀도 S-2과 S-3에서 상대증체량, 생체중 증가율과 유기물 전환효율이 높은 값을 나타내어, 지렁이 개체군의 최대 생체량을 얻기 위한 최적 사육밀도로 추정되었다. 이를 지렁이 생체중과 먹이량의 비율로 나타내면 1:32-1:48의 범위였다. 2. 사육밀도 S-1(1:16)에서 모든 조사시기의 분립생산량이 유의하게 많았고 분립비율도 유의하게 높았다($$P{\leq_-}0.05$$). 3. 사육밀도 S-3(1:48)에서 지렁이 생체중당 난포수와 분립생산량이 가장 많았다($$P{\leq_-}0.05$$). 4. 사육밀도가 높아지고 사육기간이 길어짐에 따라 분립의 전 질소함량, 유효인산함량, 양이온치환능력(CEC) 및 양이온 함량이 증가되는 경향이었다. 5. 유기농업에서 지렁이 분립은 상토 재와 토양개량제 및 작물보호를 위한 농자재로서 잠재적 유용성은 매우 높다고 판단된다.

• 한국생산제조학회지
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• 제8권4호
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• pp.13-18
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• 1999

Recently among after-treatment devices which have high possibility of utility diesel oxidation catalyst(DOC) is concerned over the world. DOC oxidizes pollutants by means of activate-reaction during by-passing in the catalyst in doing so conversion efficiency of PM, CO and HC is high and this device does not have an effect on engine performance because back pressure is not nearly increased, But as a small amount of sulfur content in fuel is oxidized it makes sulfate which is absorbed on the surface of catalyst. So in this study the experiment is carried out by means of using ordinary fuel(0.1wt%) and low sulfur fuel(0.05wt%) with DOC and the emission gas of diesel engine is measured.

• 대한환경공학회지
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• 제32권3호
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• pp.256-263
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• 2010

본 논문은 염분농도가 호기성 생분해도에 미치는 영향을 파악하고, 그 결과를 수산물 가중 폐수 처리 위한 기초자료로 사용하기 위하여 수행되었다. $Cl^-$농도(1,400~18,000 mg/L)에 따른 유기물 제거효율 검토결과, $Cl^-$ 6,000 mg/L 이하에서 미생물들은 염분에 적응하였으나 $Cl^-$ 12,000 mg/L 이상에서는 반응시간이 길어져도 처리효율이 개선되지 않는 것으로 조사되었다. 생물학적 분해불가능한 용존성 유기물 함유계수 $Y_I$와 미생물 신진대사에 의한 inert 물질 생성계수 Yp는 염분농도가 증가할수록 증가하였으며, $Cl^-$ 농도(0~18,000 mg/L)에 따른 용존성 유기물 비율은 10.8~13.1%로, 미생물 신진대사에 의한 inert 물질 생성비율은 7.0~24.6%로 조사되었다. $NH_3$-N 제거효율은, 원폐수는 HRT 18 hr에서 96.2%의 제거효율을 보였으나, $Cl^-$ 6,000 mg/L, HRT 22 hr에서 96.5%, $Cl^-$ 12,000 mg/L, HRT 30 hr에서 90.2%, $Cl^-$ 18,000 mg/L, HRT 45 hr에서 90.3%의 제거효율을 나타내, 질산화 과정이 유기물 제거 보다 염분농도에 더 민감한 것으로 조사되었으며, 폐수내 $Cl^-$ 6,000 mg/L 이상부터는 $NO_2$-N에서 $NO_3$-N로의 전환율도 낮게 조사되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권6호
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• pp.812-819
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• 2013

Forty two Malpura lambs (21 d old) were divided into three groups of 14 each consisting of 8 females and 6 males. Lambs were allowed to suckle their respective dams twice daily up to weaning (13 wks) and offered free choice concentrate and roughage in a cafeteria system. The lambs in control group were fed conventional concentrate mixture, in RBO group concentrate mixture fortified with 4% industrial grade rice bran oil and in Ca-soap rice bran oil (as in RBO group) was supplemented in the form of calcium soap. The concentrate intake decreased($p{\leq}0.05$) in RBO group as a result total dry matter, crude protein and metabolizable energy intake decreased compared to control whereas Ca-soap prepared from the same rice bran oil stimulated the concentrate intake leading to higher total dry matter, crude protein and energy intakes. The digestibility of dry matter ($p{\leq}0.05$), organic matter ($p{\leq}0.05$) and crude protein ($p{\leq}0.05$) was higher in RBO group followed by Ca-soap and control whereas no effect was observed for ether extract digestibility. Higher cholesterol ($p{\leq}0.05$) content was recorded in serum of oil supplemented groups (RBO and Ca-soap) while no effect was recorded for other blood parameters. Rice bran oil as such adversely affected and reduced the body weight gain ($p{\leq}0.001$) of lambs in comparison to control whereas the Ca-soap of rice bran oil improved body weight gain and feed conversion efficiency in lambs. Fat supplementation decreased total volatile fatty acids ($p{\leq}0.05$) and individual volatile fatty acid concentration which increased at 4 h post feeding. Fat supplementation also reduced ($p{\leq}0.05$) total protozoa count. Ca-soap of rice bran oil improved pre slaughter weight ($p{\leq}0.05$) and hot carcass weight ($p{\leq}0.05$). It is concluded from the study that rice bran oil in the form of calcium soap at 40 g/kg of concentrate improved growth, feed conversion efficiency and carcass quality as compared to rice bran oil as such and control groups.

• Asian-Australasian Journal of Animal Sciences
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• 제30권2호
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• pp.198-205
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• 2017

Objective: This study aimed to investigate the effects of single or/and double strains of probiotic supplement on feed efficiency, growth performance, and microbial population in distal gastrointestinal tract (GIT) of weaning rabbits. Methods: Sixty-four weaning (28 days old) New Zealand White rabbits were randomly distributed into four groups with treatments including: basal diet without probiotic supplement (control) or supplemented as follows: $1{\times}10^6cfu/g$ B. subtilis (BS group), $1{\times}10^7cfu/g$ L. acidophilus (LA group), or $0.5{\times}10^6cfu/g$ B. subtilis plus $0.5{\times}10^7cfu/g$ L. acidophilus (BL group). During the research, the male and female rabbits were fed separately. Body weight of the rabbits was recorded at 28, 42, and 70 d of age. Results: There was an increase (p<0.05) in body weight gain for the LA group at 42 d. Rabbits fed BL responsed with a greater growth (p<0.05) and better feed conversion ratio (p<0.05) than those fed with no probiotic. Digestibility coefficients of dry matter, organic matter, crude protein, neutral detergent fiber, and gross energy were higher (p<0.05) in LA and BL groups than those in the control group. Male rabbits had higher (p<0.05) Bacilli spp. and Coliformis spp. in the ileum than female rabbits. Rabbits supplemented with BS had greater (p<0.05) numbers of bacilli in all intestinal segments than those receiving no probiotic, whereas intestinal Lactobacilli populations were greater (p<0.001) in the LA and BL diets compared to control. Average intestinal coliform populations were lowest (p<0.05) in the rabbits supplemented with LA as compared to those fed the control and BS. Conclusion: Supplementation of L. acidophilus alone or in combination with B. subtilis at a half of dose could enhance number of gut beneficial bacteria populations, nutrient digestibility, cecal fermentation, feed efficiency, and growth performance, but rabbits receiving only B. subtilis alone were not different from the controls without probiotic.

• Asian-Australasian Journal of Animal Sciences
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• 제31권5호
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• pp.672-676
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• 2018

Objective: An experiment was conducted to study the effect of a blend of essential oils (BEO) on enteric methane emission and growth performance of buffaloes (Bubalus bubalis). Methods: Twenty one growing male buffaloes (average body weight of $279{\pm}9.3kg$) were divided in to three groups. The animals of all the three groups were fed on a ration consisting of wheat straw and concentrate mixture targeting 500 g daily live weight gain. The three dietary groups were; Group 1, control without additive; Group 2 and 3, supplemented with BEO at 0.15 and 0.30 mL/kg of dry matter intake (DMI), respectively. Results: During six months feeding trial, the intake and digestibility of dry matter and nutrients (organic matter, crude protein, ether extract, neutral detergent fibre, and acid detergent fibre) were similar in all the groups. The average body weight gain was tended to improve (p = 0.084) in Group 2 and Group 3 as compared to control animals. Feeding of BEO did not affect feed conversion efficiency of the animals. The calves of all the three groups were in positive nitrogen balance with no difference in nitrogen metabolism. During respiration chamber studies the methane production (L/kg DMI and L/kg digestible dry matter intake was significantly (p<0.001) lower in Group 2 and Group 3 as compared to control animals. Conclusion: The results indicated that the BEO tested in the present study have shown potential to reduce enteric methane production without compromising the nutrient utilization and animal performance and could be further explored for its use as feed additive to mitigate enteric methane production in livestock.

• Asian-Australasian Journal of Animal Sciences
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• 제31권8호
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• pp.1221-1229
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• 2018

Objective: A study was conducted to evaluate the varietal differences among faba bean straws and also to assess the potentials of faba bean straws supplemented with concentrate fed at the rate 70% straws and 30% concentrate mixture on feed intake, digestibility, body weight gain and carcass characteristics of the animals. Methods: Forty yearling Arsi-Bale sheep with initial body weight of $19.85{\pm}0.29kg$ (mean${\pm}$standard deviation) were grouped in a randomized complete block design into eight blocks of five animals each based on their initial body weight. Straws included in the study were from Mosisa (T1M), Walki (T2W), Degaga (T3D), Shallo (T4S), and local (T5L) varieties of faba bean and concentrate (2:1 ratio of wheat bran to "noug" seed cake). The experiment consisted of seven days of digestibility and 90 days of feeding trials followed by evaluation of carcass parameters at the end. Results: Local variety had lower (p<0.05) in grain and straw yield compared to improved varieties but higher in crude protein, metabolizable energy contents and in vitro organic matter digestibility. The apparent digestibility of dry matter and crude protein of sheep fed Walki and Mosisa straws were higher than (p<0.05) straws from Shallo varieties. Sheep fed Walki straw had greater (p<0.05) dry matter intake, average daily gain and feed conversion efficiency than sheep fed local and Shallo straws. Slaughter body weight and empty body weight were higher (p<0.05) for sheep fed Mosisa and Walki straws as compared to sheep fed Shallo straws. Apart from this, the other carcass components were not affected (p>0.05) by variety of the faba bean straws. Conclusion: There is significant varietal differences between faba bean straws both in quality and quantity. Similarly, significant variation was observed in feed intake, digestibility, body weight gain and feed conversion efficiency among sheep fed different straws of faba bean varieties with concentrate supplement. Based on these results, Walki and Mosisa varieties could be recommended as pulse crop rotation with cereals in the study area.

• 유기물자원화
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• 제15권2호
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• pp.89-97
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• 2007

본 연구에서는 하수슬러지의 가용화를 위한 처리공정으로 열처리를 수행하였다. 열처리에 의하여 입자상 유기성분의 가용화를 확인할 수 있었다. $120^{\circ}C$ 30분의 열처리에 의하여 1차 슬러지의 경우 COD기준 8.3%의 가용화효과를 나타내었다. 반면 2차슬러지의 경우 16.5%의 높은 값을 보여주었고 이는 단백질의 높은 가용화 효과에 기인하는 것으로 나타났다. 한편 모든 슬러지에 대하여 열처리에 따른 분해율 및 유기산 생성율의 향상을 확인 할 수 있었다. 단 산발효 실험을 통하여 최적 열처리조건은 대상 기질의 유기물 조성에 따라 결정되는 것으로 판단되었다. 즉 탄수화물의 함량이 높았던 1차슬러지의 경우 $80^{\circ}C$ 30분의 열처리를 통하여 최대의 분해율과 유기산 생성효과를 얻었으며 단백질의 함량이 높았던 2차 슬러지의 경우 $120^{\circ}C$ 30분이 최적의 열처리 조건인 것으로 나타났다.