• 한국물환경학회지
• /
• 제26권1호
• /
• pp.19-27
• /
• 2010

Submerged plants whose most of vegetative mass are below the water surface can have great effects on wetland biogeochemistry and water purification through their photosynthesis and nutrient uptake processes. In this study, change of dissolved oxygen concentration and pH as well as nutrient removal capacity of the submerged plant dominant wetland were investigated using wetland mesocosm experiments. Obvious periodic DO and pH fluctuation was observed due to photosynthetic activities of the submerged plants. It implies that the submerged plants can provide periodic or sequential changes of oxic and anoxic conditions that affect nitrification and denitrification processes and contribute permanent nitrogen removal in the wetland system. The pH changes in the wetland mesocosm suggested that submerged plant could also play an important role as a temporary $CO_2$ storage. Higher nutrient removal efficiency was observed in the submerged plant dominant wetland mesocosm. The removal efficiencies under experimental conditions were 38.89, 84.70, 91.21, 70.76, 75.30% of TN, DIN, $NH_4-N$, TP, $PO_4-P$ in the wetland mesocosm, while those were 26.11, 57.34, 63.87, 28.19, 55.15% in the control treatment, respectively.

• 한국물환경학회지
• /
• 제30권4호
• /
• pp.386-393
• /
• 2014

The aim of this study was to investigate the nutrient removal and biomass productivity in the wastewater using MMBR (Microalgae Membrane Bioreactor). MMBR process was combined OPPBR (Optical Panel Photobioreactor) and MBR (Membrane bioreactor). The OPPBR and MBR were operated 3 days and 9h HRT (Hydraulic retention time), respectively, using microalgae as Chlorella vulgaris. The obtained result indicated that the biomass productivity of 0.498 g/L/d with light transmittance of 92% at a 305 mm depth in the OPPBR was achieved. The total consumption of BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand) in the MMBR were found to be 97.56% and 96.06%, respectively. Additionally, the removal of TN, $NO_3-N$, TP and $PO_4-P$ were 94.94%, 91.04%, 99.54% and 93.06% in MMBR, respectively. These results indicated that the MMBR process was highly effective for COD, BOD and nutrient removal when compared to the separate OPPBR or MBR process. The MMBR process was effective for nutrient removal and biomass productivity and can be applied to treat wastewater in sewage treatment plant.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
• /
• pp.1379-1394
• /
• 1993

The purpose of this study is to examine the purification efficiency of the septic tank method which has been applied by the most of Korean livestock farms, in terms of anaerobic and aerobic treatment. Except several days in summer, BOD of effluent shows 1,500 -3,000 ppm by anaerobic process. In most cases , it exceeds according to the seasons show an increase by decrease of temperature. The removal effect on T-N is hardly found. The suspended solids contents of effluent are reduced to the level of 50-90%. Although BOD contents of effluent are kept high in the beginning, the removal rate of BOD shows 80 percent in the latter half by the aerobic treatment . The removal efficiency of total nitrogen does not appear through the experimental period, but the contents of T-N are not increased in the aerobic process unlike in the anaerobic process. The total phosphorous contents in effluent keep a constant level of 14 mg/L in average. The removal rate of phosphorous shows 91 percent i the last stage.

• Journal of Plant Biotechnology
• /
• 제48권3호
• /
• pp.193-200
• /
• 2021

본 연구는 생육 기간에 따른 새싹보리 식물체의 길이, 무게 및 클로로필 함량 분석과 수확량을 통해 양액 처리에 따른 재배 효율성을 평가하고, 생산된 새싹보리의 무기성분 분석과 용매별 추출물의 총 폴리페놀 및 총플라보노이드 함량과 HPLC를 이용한 기능성 물질 분석을 통해 새싹보리의 산업적 이용 가능성을 높이고자 하였다. 새싹보리의 생육에서 무처리구보다 양액 처리구에서 생육속도가 빨랐으며 특히 지상부 길이가 크게 신장하였다. 지상부 길이가 더 증가한 만큼 생체중 또한 증가하였지만 수분 흡수량의 차이보다는 건물중의 증가로 이어졌다. 이는 수확량의 차이로 나타났다. 무처리구와 비교하였을 때 양액 처리구에서 생산량이 유의적으로 증가하였다. 클로로필 함량 분석을 통해 생육 9일차에서 광합성을 통한 독립영양 과정을 확인하였고, 생육 3일차와 6일차에서 양액 처리를 통한 무기성분 투입이 초기 생장에 보조적인 효과가 있다고 판단된다. 새싹보리의 폴리페놀 함량 분석 결과 총 폴리페놀 함량은 무처리구에서 높았지만 총플라보노이드 함량과 luteolin 함량은 양액 처리에 의해 증가하였다. 또한 추출 용매를 물로 사용하였을 때 폴리페놀 추출에 효과적이었다. 따라서 새싹보리 수경재배에서 양액의 투입이 높은 폴리페놀을 가진 새싹보리를 생산하고 생산량 증대에도 효과가 있음을 시사한다.

• 상하수도학회지
• /
• 제26권6호
• /
• pp.833-840
• /
• 2012

This study aimed to investigate growth rate and nutrient removal efficiency of Chlorella vulgaris according to nitrogen sources and frequency of pH adjustment. Nitrogen and phosphorus removal efficiencies were evaluated in the three different conditions using $NO_3{^-}$, $NH_4{^+}$ as a sole nitrogen source and mixed condition. Initial nutrient concentrations in artificial wastewater were 30 mg-N/L and 3 mg-P/L similar to secondary wastewater effluent. When nitrogen source was $NO_3{^-}$, there was no inhibition on the growth of C. vulgaris with adjusting pH every 24 hr while growth inhibition occurred with $NH_4{^+}$ caused by pH drop. N, P removal efficiencies were no significant depending on the nitrogen sources. As pH was adjusted to 7 by pH-stat, growth rate and nutrient removal efficiencies were increased compared to adjusting pH every 24 hr, however, growth rate and nutrient removal efficiencies were no significant depending on the nitrogen sources.

• Animal Bioscience
• /
• 제34권6호
• /
• pp.1061-1069
• /
• 2021

Objective: This study was conducted to evaluate the effects of feed processing and particle size on growth performance, nutrient digestibility, carcass characteristics, and gastric health in growing-finishing pigs. Methods: A total of 360 growing pigs (22.64±0.014 kg initial body weight [BW]) were allocated to 1 of 6 treatments with 6 replicates by BW and sex, and 10 pigs were housed in one pen in a randomized complete block design. The BW and feed intake were recorded to calculate growth performance. For the digestibility trial, a total of 24 barrows with an initial BW of 33.65±0.372 kg were split into 6 treatments with a completely randomized design. Dietary treatments were designed by a 2×3 factorial arrangement of treatments based on two main factors, particle size (600, 750, 900 ㎛) and feed form (mash and pellet) of diet. Experimental diets were formulated to contain the requirements of the NRC (2012). Results: The BW and average daily gain were not changed by dietary treatments, and the feed intake of finishing pigs (wks 6 to 12) was increased when the pigs were fed a mash diet (p<0.05). For the overall period, the feed efficiency of pigs was improved with the pellet diet (p<0.01) and reduced particle size (p<0.05). The pellet diet had effects on increasing crude fat digestibility (p<0.01) relative to a mash diet, but there was no considerable change in dry matter and crude protein digestibilities by dietary treatments. In the evaluation of gastric health, a trend for an increased incidence of keratinization in the esophageal region was observed as particle size decreased (p = 0.07). Conclusion: Feed efficiency could be improved by pellet diet and reduced particle size. Nutrient digestibility, carcass characteristics, and gastric health were not affected by feed form, and particle size ranged from 600 to 900 ㎛.

• Animal Bioscience
• /
• 제34권4호
• /
• pp.633-641
• /
• 2021

Objective: The effects of adding fermented feed to a pelleted total mixed ration (PTMR) on the growth performance of lambs remain unclear. The present study aimed to investigate the feed efficiency and productivity of lambs that were fed PTMR containing fermented soybean meal (FSM) or wheat bran (FWB). Methods: Sixty 90-d-old hybrid lambs were randomly allocated into 12 pens (5 lambs/pen) that were randomly assigned to 4 dietary treatments (3 pens/treatment) with PTMR (basal diet), 2% FSM, or Lactobacillus- or yeast-FWB (L-FWB or Y-FWB) addition in the basal diet. Results: The findings showed that lambs fed 2% FSM supplemented diet had enhanced (p<0.05) average daily gain (ADG) and carcass yield (p = 0.015), while they had a decreased (p = 0.006) feed conversion ratio compared to that of other three groups. Inclusion of FSM or FWB in PTMR improved (p<0.05) the nutrient digestibility, while it reduced the urea nitrogen content in serum compared to the PTMR group. Additionally, the decreased ratio of N excretion to ADG (p<0.01) was observed with FSM and L-FWB supplementation compared with the PTMR and Y-FWB groups. Conclusion: In conclusion, feeding the fermented feed-supplemented diet improved nutrient digestibility and growth performance, and 2% FSM-supplemented diet exhibited superior production-promoting efficiency to lambs.

• Animal Bioscience
• /
• 제35권10호
• /
• pp.1585-1591
• /
• 2022

Objective: The present study examined the effects of exogenous emulsifiers and multi-enzyme supplementation into a low energy density diet on growth performance, visceral organ parameters, blood metabolites, ileal morphology, and nutrient digestibility in broiler chickens from hatch to 21 days. Methods: One hundred and sixty-eight one-day-old Ross 308 broiler chickens were allocated in a completely randomized design to 24 pens and each pen was assigned to one of four dietary treatments to give six replications with seven chickens in a cage. Dietary treatments were: i) positive control with standard energy level (PC); ii) negative control with 100 kcal/kg lower energy of the standard level (NC); iii) NC diet supplemented 0.05% calcium stearoyl-2 lactylate as an emulsifier (NC+E); and iv) NC diet supplemented with both 0.05% calcium stearoyl-2 lactylate and 0.05% multi-enzyme (NC+E+M). Corn and soybean meal-based control diets containing vegetable oil were formulated to meet the Ross 308 nutrition specification. Chickens were fed ad-libitum with the treatment diets and sampling was conducted on day 21. Results: Our results revealed that emulsifier and multi-enzyme supplementation into NC diets improved (p<0.05) feed efficiency of the broiler chickens compared to the broiler chickens fed NC diets from hatch to 21 days. Supplementation of emulsifier and multi-enzyme into NC diet improved (p<0.05) nutrient digestibility of the broiler chickens. However, emulsifier and multi-enzyme supplementation into diet did not influence (p>0.05) visceral organ weight, blood metabolites, and intestinal morphology in broiler chickens fed NC diets. Conclusion: Supplementation of emulsifier and multi-enzyme in the NC diet would support improving growth performance in young broiler chickens with improved feed efficiency and increased nutrient digestibility thereby curtailing the negative impact of energy reduction in the diets.

• 생물환경조절학회지
• /
• 제17권4호
• /
• pp.252-260
• /
• 2008

본 실험은 장미 식물공장에서 single-node cutting 'Versillia'의 양분흡수 특성을 구명하고 순환식 수경재배 시스템에 적합한 배양액 내 무기이온 조절방식을 구명하고자 수행하였다. 실험 기간동안 각 처리별 배양액 내 무기이온함량 변화를 살펴본 결과 EC 제어구의 경우 $NO_3$-N은 생육 후반이 되면 그 함량이 적정 범위 이상으로 증가 하였고 P와 Mg은 감소하였으며 배양액 첨가구는 전체적인 배양액 내 무기이온 함량이 증가하였다. 이에 비해 무기이온 제어구는 생육 기간동안 근권 내 적정 범위를 유지하였다. 광합성 효율을 나타내는 지표 중 하나인 Fv/Fm는 무기이온제어구와 배양액 첨가구에서 높았고 절화장, 생체중 등은 무기이온 제어구에서 높았다. 그러나 뿌리의 활성 정도를 측정해본 결과 무기이온 제어구에서 높았으나 배양액 첨 가구에서는 생육 초기에 배양액 내 pH 변화폭이 커서 가장 낮게 나타났다. 위의 결과를 종합하였을 때, 무기이온 조절(다량 미량원소 제어구와 다량원소 제어구)을 통해 배양액을 관리하는 것이 생육 전 기간 동안 근권 환경을 적절히 유지해 줄 수 있었고 이에 따라 절화 품질도 향상되므로 장미(single-node cutting) 순환식 수경재배에 적합한 근권 환경 제어방식이라고 할 수 있다.

• 한국습지학회지
• /
• 제15권4호
• /
• pp.453-460
• /
• 2013

소규모 농촌 지역 하수도 보급률은 도시지역의 약 40% 이하 수준이다. 농촌지역의 낮은 하수도 보급률은 상수원의 수질악화의 원인으로 보고되고 있다. 안동댐과 임하댐 상류에 위치하고 있는 봉화군에 신설된 마을하수도 11개소의 운전 결과를 분석하였다. 운전결과를 바탕으로 봉화군 마을하수도 특성과 도입된 처리 공법에 관한 분석을 실시하였다. 봉화군 유입 하수는 도시지역에 비해 고농도의 유기물과 영양염류를 함유하고 있다. 마을하수도에 도입된 처리 공법은 전체적으로 안정적인 처리 효율을 보였다. 하지만 영양염류의 경우 처리 효율의 변화가 크게 나타났다. 이는 마을하수도 운전 시영양염류 처리에 있어 운전 조건 관리에 관심을 기울여야 한다는 것을 의미한다.