• Title/Summary/Keyword: 물 순환 시스템

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A Study for Field Application of Environmental-friendly Waterproof Method for Riverbed (친환경 하상차수공법 현장 적용성에 관한 연구)

  • Park, Minchul;Kim, Seonggoo;Kwak, Nokyung;Shin, Hyohee;Lee, Song
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.1
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    • pp.71-80
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    • 2011
  • In period of rapid economic development, as doing river conservation work by using harmful materials environmental pollution has adversely effected humans, animals and plants frequently. For recovery of environmental pollution it needs a lot of time and cost. Therefore, in this study, in order to take an environment-friendly method which is also economical and durable both results of the laboratory model test and field test were compared and analyzed. According to the results of the laboratory model test, those methods such as concrete paving, asphalt paving, bentonite mat, stabilized soil method and mixed soil method have small amount of seepage, but on the other hand compaction soil, grassland and permeable materials have considerable amount of seepage. The results of field test show a similar tendency with laboratory test and have been satisfied to assess standard of domestic water permeability below $1.0{\times}10^{-7}cm/sec$ and unconfined compressive strength is also than 1.0MPa so it has been satisfied about standard. In conclusion, as compaction rate increased, as unconfined compression strength increased and coefficient of permeability decreased.

Correlation analysis of pollutants using IoT technology in LID facilities (LID 시설 내 IoT 기술을 활용한 오염물질 상관성 분석)

  • Jeon, Minsu;Choi, Hyeseon;kevin, Geronimo Franz;Reyes, N.J.DG.;Kim, Leehyung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.453-453
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    • 2021
  • 도시지역 비점오염원관리, 물순환 회복, 침투 및 증발산량 증가, 열섬현상 저감을 위한 주요한 방안으로 저영향개발(low impact development, LID)과 그린인프라 기법의 적용되고 있다. LID 시설은 소규모 분산형 시설로써 넓은 지역에 많고 다양한 시설들이 적용되어 시설의 개수가 많으며, 수질 및 토양 내 기성제품에 대한 센서들의 가격은 고가로 형성되어 있어 기기의 경제성 및 유지관리 등 적용하는데 제한적이다. 따라서 과거 모니터링 자료를 기반으로 오염물질들과의 상관성 분석을 통하여 계측이 어려운 항목들을 계측가능한 항목들로부터 예측 가능하며, 선정된 항목들에 대한 비용효율적인 센서를 개발하여 실시간 LID 모니터링이 가능한 비용효율적 모니터링을 개발하였다. 공주대학교 천안캠퍼스의 LID 시설들은 2013년에 조성되어 현재까지 시설이 운영되고 있으며, 5년이상의 과거 강우시 모니터링 자료들을 이용하여 오염물질 상관성 분석을 수행가능 하기에 대상지로 선정하였다. 오염물질 상관성 분석은 2013년부터 2017년도에 침투도랑에서 수행된 강우시 모니터링 자료를 활용하여 각 오염물질들의 상관성을 분석을 수행하였다. 침투도랑 내 유입되는 평균 유입수는 TSS 286.1±318.3 mg/L, BOD 22.6±39.5 mg/L, TN 8.96±5.85 mg/L, TP 1.01±1.11 mg/L로 나타났다. 겨울철에 비해 여름철에서의 오염물질의 유입농도가 높은 것으로 분석되었다. 이는 여름철 고온건조로 인한 노면 내 차량의 주행으로 인한 중금속, 폐타이어 등과 장마철 강우 시 유출된 토사로 인하여 유입수의 농도가 높은 것으로 분석되었다. 오염물질 부하량은 TSS와 COD 0.66으로 유의성이 높은 것으로 나왔으며, COD와 TSS, TP, TN 등 유의성이 높은 것으로 분석되었다. Arduino와 Raspberry PI를 활용하여 저비용 센서와 LTE 모뎀통신과 데이터 베이스 연결하여 개발된 프로그램을 통해서 무선으로 LID 시설에 대한 모니터링을 침투화분2와 식생체류지에 조성하였다. 전력공급이 어려운 식생체류지의 경우 태양열(Solar system) 시스템과 보조 전력 배터리를 조성하여 장마철이나 장기적인 악천후로 인한 전력을 생산하지 못할 경우 보조전력배터리에서 전력을 제공하여 지속적인 모니터링이 이루어지도록 설계하였다. 토양함수량, 토양온도와 Conductivity 등 3종류의 센서를 적용하였으며, 프로그램은 현재 2단계를 통한 2차수정을 통하여 프로그램을 구축하였다. 오차, 오작동, 계측값에 대한 검·보정 작업이 필요하다. 또한 대기자료의 구축을 통해 보다 토양과 LID 시설에 대한 영향분석이 필요한 것으로 사료된다.

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Parameter Sensitivity Analysis of VfloTM Model In Jungnang basin (중랑천 유역에서의 VfloTM 모형의 매개변수 민감도 분석)

  • Kim, Byung Sik;Kim, Bo Kyung;Kim, Hung Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.6B
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    • pp.503-512
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    • 2009
  • Watershed models, which are a tool for water cycle mechanism, are classified as the distributed model and the lumped model. Currently, the distributed models have been more widely used than lumped model for many researches and applications. The lumped model estimates the parameters in the conceptual and empirical sense, on the other hand, in the case of distributed model the first-guess value is estimated from the grid-based watershed characteristics and rainfall data. Therefore, the distributed model needs more detailed parameter adjustment in its calibration and also one should precisely understand the model parameters' characteristics and sensitivity. This study uses Jungnang basin as a study area and $Vflo^{TM}$ model, which is a physics-based distributed hydrologic model, is used to analyze its parameters' sensitivity. To begin with, 100 years frequency-design rainfall is derived from Huff's method for rainfall duration of 6 hours, then the discharge is simulated using the calibrated parameters of $Vflo^{TM}$ model. As a result, hydraulic conductivity and overland's roughness have an effect on runoff depth and peak discharge, respectively, while channel's roughness have influence on travel time and peak discharge.

Ammonia Removal Capacities of Several Filter Media in a Seawater Recirculating Aquaculture System (해수 순환 여과 양식 시설의 여과 재료별 암모니아 제거 능력)

  • 전임기;손맹현;조재윤;이종문
    • Journal of Aquaculture
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    • v.10 no.3
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    • pp.261-271
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    • 1997
  • Ammonia removal capacities of five submerged filter media, 2~3mm sand, 30~50mm gravel, 20~40mm coral sand, polythylene net, and corrugated plastic plate in a seawater recirculating system were tested. A rotating biological contactor (RBC) was also tested for comparison. Oxygen consumption rates were measured along with the ammonia removal efficiencies. The ammonia concentrations in the system were maintained from 0.052 to 0.904 mg/l (mean 0.338$\pm$0.219 mg/l) and the water temperature was ranged from 19.2 to $21.4^{\circ}C\;(mean 20.2^{\circ}C\pm0.58^{\circ}C$). The 1/2-order kinetic model (Y:g/$m^3$/day) and the mean ammonia removal rates (g/$m^3$/day) of the filter media were : Sand : Y=135.5X0.5-25.1(r2=0.8110), 45.1 Coral sand : Y=125.1X0.5-33.0 (r2=0.7307), 31.8 Polyethylene net : Y=87.4X0.5-20.1 (r2=0.6780), 25.2 Corrugated plastic plate : Y=87.4X0.5-20.1(r2=0.5206), 19.2 Gravel : Y=4307X0.5-5.5 (r2=0.2596), 17.1 RBC : Y=127.6X0.5-33.4 (r2=0.7146), 32.8 where X is the concentration of ammonia. Oxygen consumption rates well corresponded to the ammonia removal capacities of each filter medium, thus the sands showing the highest value (442g/$m^3$/day) followed by coral sands (291.1g/$m^3$/day), polyethylene nets (236.9g/$m^3$/day), gravels (135.6g/$m^3$/day) and corrugated plastic plates (134.2g/$m^3$/day). Oxygen consumption rate of the RBC was unable to measure because of the characteristics of the structure.

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Interaction Between Groundwater and Stream Water Induced by the Artificial Weir on the Streambed (하상 인공구조물에 의해 유도되는 지하수-하천수 시스템의 상호작용)

  • Oh, Jun-Ho;Kim, Tae-Hee;Sung, Hyun-Cheong;Kim, Yong-Je;Song, Moo-Young
    • Journal of Soil and Groundwater Environment
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    • v.12 no.2
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    • pp.9-19
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    • 2007
  • This study investigated the interaction between groundwater and stream water systems, which is caused by the artificial weir on streambed, enforcing external stresses on the groundwater system. The study area is in Nami Natural Recreation Woods located in Chungcheongnam-do Geumsan-gun Nami-myeon Geoncheon-ri. In this study both of hydrophysical methods (hydraulic head) and hyrdochemical investigations (pH, EC, major ion analysis) were applied. In order to identify the relationship between each of study results, cross-correlation analysis is performed. From results of hydrophysical methods, water level fluctuation at BH-14, installed by the weir, shows the double-recession pattern much more frequently and much higher amplitudes than the fluctuation at each of other monitoring wells. Using the results by hydrochemical investigations, hydrochemical properties at BH-14 is similar to the hydrochemical characteristics in stream water. To analyze the interrelationships between the results from each of applied methods, cross-correlation analysis was applied. Results from the correlation analyses, water levels at BH-14 and stream weir showed the highest cross-correlation in hydrophysical aspects. On the other hand, the correlation between stream weir and bridge was the highest in hydrochemical aspects. The difference between the results from each of methods is due that the hydrophysical response at BH-14, such as water level, is induced by the pressure propagation-not with mass transfer, but the hydrochemical interaction, caused by mass transport, takes much more times. In conclusion impermeable artificial weir on streambed changes the interfacial condition between the stream and surrounding aquifers. The induced water flux into the groundwater system during flood period make water level at BH-14 increase instantly and groundwater quality higly similar to the quality of stream water. Referred similarities in both of water level and water quality at BH-14 become much higher when water level at weir grow higher.

Establishment of the Heart Failure Model by Coronary Artery Ligation in Sheep (양에서 관상동맥 결찰에 의한 심부전 모델의 확립)

  • 나찬영;홍장수;박정준;김원곤;강문철;서정욱
    • Journal of Chest Surgery
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    • v.35 no.1
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    • pp.1-10
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    • 2002
  • Background: Despite the relatively high mortality rates in the chronic heart failure model induced by coronary artery ligation are relatively high, this model has been a subject of continuos research because of its clinical correlation. Chronic heart failure model of large-sized animals is very useful to analyse mechanical or biological effects on circulatory system which is difficult in small-sized animals. The purpose of this study is to establish the heart failure model by coronary artery ligation in sheep. Material and Method: Among 9 Corridale sheep, the homonymous artery and the diagonal branch were ligated simultaneously in 2 sheep and remaining 7 sheep were assigned to successive ligation of both arteries at an interval of 1 hour. Both coronary arteries were ligated from the point 40% proximal to the apex of the heart. Hemodynamic and echocardiographic parameters were analyzed before the ligation of the coronary artery, after the ligation of the homonymous artery, and after additional ligation of the diagonal branch. The experimental animals were sacrificed after 2 or 3 months of growth and histopathologic studies were performed Result: Immediate postoperative death occurred in the 2 sheep that had received simultaneous ligation of the homonymous artery and diagonal branch. On the other hand, all the 7 sheep that were lifated in succession were survived up to 3 months. Arterial pressure was sifnificantly decreased immediately after ligation of the homonymous artery(p<0.05), and the cardiac output was decreased and pulmonary capillary wedge pressure was increased after further ligation of the diagonal branch(p<0.05). Central venous pressure, pulmonary artery pressure, pulmonary capillary wedge pressure, left ventricular end-diastolic dimension and end-systolic dimension were markedly increased 3 months after ligation of coronary arteries. Anteroseptal akinesia or dyskinesia was developed after the ligation of coronary arteries. Histopathologic study revealed we]1-demarcated ischemic area of fibrosis. Conclusion: Using methods of successive ligation of the homonymous artery and diagonal branch, chronic heart failure model could be reliably established in sheep.

Heating Efficiency of Difference Heat Collection Methods for Greenhouse (유리온실의 태양열 집열방법별 집열효과)

  • 최영하;이재한;권준국;박동금;이한철
    • Journal of Bio-Environment Control
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    • v.9 no.3
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    • pp.166-170
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    • 2000
  • Three methods for heat collection, which were the flat solar collector, two fan with radiator, and square pipe method, were studied to sue efficiently solar energy in the three different glasshouses for two years. The flat plate solar collector method was made use of the commercial solar collector with collection area of 24$m^2$, the method of two fans with radiators collected solar energy at the top of the glasshouse. An thermal storage tank was constructed underneath in teach glasshouses. When an area of 1,000$m^2$ was heated to the minimum temperature of 9$^{\circ}C$, the decrease rate of heating fuel for the flat plate solar collector, the fan attached radiator and the square pipe methods were 7%, 19% and 28% respectively. The flat plate solar collector method, which could be heated approximately 40-50$m^2$, was currently used by most of the farmer. Under the condition, the decrease rate of annual heating fuel was 14% which was not better for an economic annual heating fuel. If the fan with radiator method was operated, the use of installation and maintenance were required. So, it could not be good economic efficiency of solar heating. The heating efficiency of the square pipe method was relatively better thant those of the flat plate solar collector or the fan attached radiator. Since the cost of materials and its installation of the use of square pipe method was lower than any other method. However, corrosion of the pipe, greater shade in the greenhouse and strength against the square pipe were problems that should be overcome in the square pipe method.

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Simulation of Soil Moisture in Gyeongan-cheon Watershed Using WEP Model (WEP 모형을 이용한 경안천 토양수분 모의)

  • Noh, Seong-Jin;Kim, Hyeon-Jun;Kim, Cheol-Gyeom;Jang, Cheol-Hee
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.720-725
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    • 2006
  • 토양수분은 식물의 생장 및 가용수자원 산정 등에 있어서 중요한 요소로서 토양층 상부의 수 m내에 존재하는 수분의 양을 일컫는다. 토양수분과 토양수분의 공간적 시간적 특징들은 증발, 침투, 지하수 재충전, 토양침식, 식생 분포 등을 지배하는 중요한 요소이다. 강우 등으로 인한 지면과 지표하에서의 순간적인 포화공간의 형성 및 유출의 생성 등을 포함하는 과정과 증발산 등은 모두 비포화대(vadose zone) 혹은 토양층에서의 토양수분의 함량에 크게 의존하게 된다(이가영 등(2005)). 분포형 수문모형은 유역을 격자단위로 세분화하여 매개변수를 부여하고, 증발산, 침투, 지표면유출, 중간유출, 지하수유출, 하도 흐름 등 여러 가지 수문요소를 해석하는 종합적인 수문모형이다. 지표면에 내린 강우가 증발, 침투, 유출될 지는 토양수분의 함량에 크게 의존하게 되며, 따라서 토양수분에 대한 적절한 모의가 분포형 수문모형의 정확도를 좌우하는 핵심이라 할 수 있다. 본 연구에서는 분포형 수문모형인 WEP 모형을 경안천 유역(유역면적: $575km^2$, 유로연장: 49.3㎞)에 적용하여 토양수분의 시공간분포를 모의하였다. 지점별 토양수분 모의결과, 토양 매개변수의 최대, 최소값 내에서 적절히 모의됨을 확인하였으나, 관측값이 없어 실질적으로 타당한지 여부는 검증하지 못하였다. 토양수분비율, 연간 증발산량, 지표면 유출량 공간분포를 비교한 결과, 토양수분비율이 연간 증발산량 모의에 직접적인 영향을 주는 것을 확인할 수 있었다. 일부격자에서는 토양수분이 지나치게 높게 모의되었는데, 지하수위와 관련있는 것으로 보이며, 구축된 자료가 부족한 지하대수층에 대한 정보부족이 토양수분 계산에도 영향을 준 것으로 보인다. 본 연구는 WEP 모형의 토양수분 해석능력에 대한 시험적용에 그 의의가 있으며, 향후 토양 및 지표하 매개변수 정보가 충분히 갖추어지고, 토양수분 관측결과 있는 대상유역에 대한 적용이 요구된다.-Moment 방법에 의해 추정된 매개변수를 사용한 Power 분포를 적용하였으며 이들 분포의 적합도를 PPCC Test를 사용하여 평가해봄으로써 낙동강 유역에서의 저수시의 유출량 추정에 대한 Power 분포의 적용성을 판단해 보았다. 뿐만 아니라 이와 관련된 수문요소기술을 확보할 수 있을 것이다.역의 물순환 과정을 보다 명확히 규명하고자 노력하였다.으로 추정되었다.면으로의 월류량을 산정하고 유입된 지표유량에 대해서 배수시스템에서의 흐름해석을 수행하였다. 그리고, 침수해석을 위해서는 2차원 침수해석을 위한 DEM기반 침수해석모형을 개발하였고, 건물의 영향을 고려할 수 있도록 구성하였다. 본 연구결과 지표류 유출 해석의 물리적 특성을 잘 반영하며, 도시지역의 복잡한 배수시스템 해석모형과 지표범람 모형을 통합한 모형 개발로 인해 더욱 정교한 도시지역에서의 홍수 범람 해석을 실시할 수 있을 것으로 판단된다. 본 모형의 개발로 침수상황의 시간별 진행과정을 분석함으로써 도시홍수에 대한 침수위험 지점 파악 및 주민대피지도 구축 등에 활용될 수 있을 것으로 판단된다. 있을 것으로 판단되었다.4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전략은 존재하므로 이러한 전략을 개발 및 활용할 수 있으며, 특히, 한국주식시장에 적합한 거래전략은 반전거래전략이고, 이 전략의 유용성은 투자자가 설정한 투자기간보다 더욱 긴 분석기간의 주식가격정보에 의하여 최대한 발휘될 수 있음을 확인하였다.(M1), 무역적자의

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Effects of Several Cooling Methods and Cool Water Hose Bed Culture on Growth and Microclimate in Summer Season Cultivation of Narrowhead Goldenray 'Ligularia stenocephaia' (곤달비 여름재배 시 냉각방법과 냉수호스베드재배가 생육 및 미기상에 미치는 영향)

  • Kim, Ki-Deog;Lee, Eung-Ho;Kim, Won-Bae;Lee, Jun-Gu;Yoo, Dong-Lim;Kwon, Young-Seok;Lee, Jong-Nam;Jang, Suk-Woo;Hong, Soon-Choon
    • Journal of Bio-Environment Control
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    • v.20 no.2
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    • pp.116-122
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    • 2011
  • This study was carried out to investigate the effects of several cooling methods such as water hose cooling, mist, fog and control on growth and microclimate, and to develop a simple nutriculture bed for production of fresh leaves of narrowhead goldenaray 'Ligularia stenocephala'. When the root-zone was cooled with 240 L/hr flow rate of $13^{\circ}C$ ground water using water hose, the temperature was lowered approximately by 2 to $3^{\circ}C$ than that of control. The growth of narrowhead goldenaray were favorable in the water hose cooling compared with the other cooling methods. Nutrient culture system having part cooling effect around plant canopy was developed. The system was composed of 15 cm diameter of water hose on side wall of beds, cooling hose, and expanded rice hull media as organic substrate. When cool water which the temperature changed in the range of 14 to $22^{\circ}C$ diurnally with 240 L/hr of flow rate through water hose, the air temperature around canopy and root-zone temperature were dropped by $0.5^{\circ}C$ and $3^{\circ}C$ compared with that of conventional styrofoam bed, respectively. These results showed that newly devised bed system using water hose was simple and economical for the production of high quality narrowhead goldenaray leaves. This system might be practically used both at summer and winter season for the cultivation of narrow head goldenaray by part cooling or heating around root-zone and plant canopy.

Nutrient Recovery from Sludge Fermentation Effluent in Upflow Phosphate Crystallization Process (상향류 인 결정화공정을 이용한 슬러지 발효 유출수로 부터의 영양소 회수)

  • Ahn, Young-Ho
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.8
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    • pp.866-871
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    • 2006
  • The nutrient recovery in phosphate crystallization process was investigated by using laboratory scale uptlow reactors, adopting sequencing batch type configuration. The industrial waste lime was used as potential cation source with magnesium salt($MgCl_2$) as control. The research was focused on its successful application in a novel integrated sludge treatment process, which is comprised of a high performance fermenter followed by a crystallization reactor. In the struvite precipitation test using synthetic wastewater first, which has the similar characteristics with the real fermentation effluent, the considerable nutrient removal(about 60%) in both ammonia and phosphate was observed within $0.5{\sim}1$ hr of retention time. The results also revealed that a minor amount(<5%) of ammonia stripping naturally occurred due to the alkaline(pH 9) characteristic in feed substrate. Stripping of $CO_2$ by air did not increase the struvite precipitation rate but it led to increased ammonia removal. In the second experiment using the fermentation effluent, the optimal dosage of magnesium salt for struvite precipitation was 0.86 g Mg $g^{-1}$ P, similar to the mass ratio of the struvite. The optimal dosage of waste lime was 0.3 g $L^{-1}$, resulting in 80% of $NH_4-N$ and 41% of $PO_4-P$ removal, at about 3 hrs of retention time. In the microscopic analysis, amorphous crystals were mainly observed in the settled solids with waste lime but prism-like crystals were observed with magnesium salt. Based on mass balance analysis for an integrated sludge treatment process(fermenter followed by crystallization reactor) for full-scale application(treatment capacity Q=158,880 $m^3\;d^{-1}$), nutrient recycle loading from the crystallization reactor effluent to the main liquid stream would be significantly reduced(0.13 g N and 0.19 g P per $m^3$ of wastewater, respectively). The results of the experiment reveal therefore that the reuse of waste lime, already an industrial waste, in a nutrient recovery system has various advantages such as higher economical benefits and sustainable treatment of the industrial waste.