• Title/Summary/Keyword: cod stock

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Optimum Concentration of Alizarin Complexone (ALC) for Otolith Marking of Pacific Cod Gadus macrocephalus (대구 Gadus macrocephalus 이석 표지를 위한 Alizarin Complexone의 최적 농도)

  • Kim, Tae Jin;Lee, So Gwang;Gwak, Woo Seok
    • Korean Journal of Ichthyology
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    • v.20 no.4
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    • pp.272-278
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    • 2008
  • Optimum concentration of alizarine complexone (ALC) for staining of otoliths for Pacific cod was determined by examination of stained quality, growth and survival rates. Small juveniles ($34.1{\pm}1.8mm$ TL, $mean{\pm}SD$) were immersed in four different concentrations (20, 40, 60, 80 mg/L) and large ones ($73.8{\pm}1.2mm$ TL, $mean{\pm}SD$) in five different concentrations (1, 5, 10, 20, 40 mg/L) of ALC for 24 hrs. The fish were then reared and observed for 14 days. The stained quality of otoliths was evaluated by dividing them into four grades by the presence of fluorescent stains on the otoliths under G-excited UV light. The small juveniles stained with the different ALC concentrations had 100% staining success, and their growth rate and body weight did not differ significantly between treatments. Optimal ALC concentration for the smaller juveniles was 20 mg/L in the present experiment. On the other hand, distinct fluorescent rings were confirmed on otoliths of larger juveniles in the 10 mg/L treatment with high survival rate. These results suggest that ALC staining at concentrations of 10 mg/L with larger juveniles will be helpful for release-recapture experiments for stock enhancement of Pacific cod.

Water Quality Prediction Model in a Lake by Finite Element Method;Application to Sapkyo Lake (유한요소법에 의한 호소의 수질예측모형;삽교 담수호에 적용하여)

  • Ryu, Byong-Ro;Ahn, Sang-Jin
    • Korean Journal of Environmental Agriculture
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    • v.8 no.1
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    • pp.37-46
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    • 1989
  • A 2-dimensional pollutant transport phenomenon in shallow reservoirs was analyzed by using a finite element method. The Galerkin's weighted residual method, based on linear interpolation, was used and a triangle was adopted as an element. The two dimensional Stock's equation and the advection-diffusion equation integrated over depth were used as governing equations. Also the Newton-Raphson method was introduced to solve the non-linear terms of the equation. The results calculated by the model are in good agreement with the analytical solution for a simplified channel where a known solution is avaiable. An actual application of the model is attempted for Sapkyo Lake with a consideration of the influx of the Sapkyo Chun, the Muhan Chun and kogkyo Chun. Further refined research is needed to evaluate the water quality in the other reservoirs.

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Characterization of Microbial Community Changes in Process Affected by Physicochemical Parameters During Liquid Fertilization of Swine Waste

  • Shin, Mi-Na;Kim, Jin-Won;Shim, Jaehong;Koo, Heung-Hoe;Lee, Jai-Young;Cho, Min;Oh, Byung-Taek
    • Korean Journal of Soil Science and Fertilizer
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    • v.46 no.3
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    • pp.173-181
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    • 2013
  • Livestock wastes are considered as major environmental pollutants because they contain high concentration of organic materials. In 2001, The Environmental Department reported that stock farmers were increasing as 5.1%/year, which resulted in a gradual increase in livestock wastes generation. The direct disposal of livestock wastes create several environmental problems. Thus, several countries banned the disposal of livestock wastes in environment including aquatic systems. Recently, aeration-based liquid fertilization was considered as potential way for the disposal of livestock wastes. In this study, next generation sequencing (NGS) analysis was used to understand the microbial community changes during liquid fertilization of livestock wastes. Microbial community was compared with liquid fertilizer physicochemical analysis such as $BOD_5$, $COD_{Mn}$ pH, N (Nitrogen), P (Phosphorus), K (Potassium) etc. The physicochemical parameters and bacterial community results pave the way for producing effective livestock-based fertilizer. By comparing the physical characteristics of the manure with microbial community changes, it is possible to optimize the conditions for producing effective fertilizer.

Methods for the Reduction of Consumption and Contamination of Water in a Newsprint Mill by Using Simulation Model and WRDF (전산모사기법과 WRDF를 활용한 ONP 재활용 공정의 용수 및 오염부하 절감 방안에 관한 연구)

  • 이영애;류정용;성용주;김용환;송재광;송봉근;서영범
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.2
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    • pp.54-59
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    • 2004
  • The methods for the minimization of fresh water consumption, waste water generation and water contamination have been greatly investigated and developed for last ten years. Recently, the rising cost of waste water treatment and the more strict environmental regulation lead to the higher demand of more efficient and systematic methods for process water management. The water reuse technology, which not only reduce the process water needs but also minimize waste water generation within the process, could be one of most efficient way for current demand. In this study, the practical way for reduction of water pollution and optimal reuse or recycle of process water in a newsprint mill was investigated by using a simulation model. The result of computer simulation showed that the COD level of approach system could be reduced by 50% after the stock concentration at the 2nd disc filter was increased upto 30%. The application of WRDF(Wrinkled Rotary Drum Filter) to the newsprint mill was carried out with pilot scale. The process water treated by WRDF had enough cleanliness to substitute the forming fabric shower water with the PDF water, which could result in the 30% reduction in fresh water consumption.

The Occurrences of Pharmaceutical and Personal Care Products (PPCPs) in Mankyung River, South Korea (만경강 수중에서 신체보초제품(PPCPS)의 잔류)

  • Kim, Joon-Woo;Kim, Jong-Gu;Jang, Hyo-Sang;Cho, Hyeon-Seo;Takao, Yuji;Arizono, Koji
    • Journal of Environmental Science International
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    • v.18 no.3
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    • pp.245-254
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    • 2009
  • In recent years, environmental pollution by phannaceuticals and personal care products (PPCPs) in the aquatic environment is of great concern worldwide. Recent studies have been reported to occur in a variety of environmental organisms such as surface, drinking and ground water, soils, sediments and hospitals. The purpose of this study was to evaluate the occurrence and environmental behavior of fourteen human PPCPs in surface waters of Mankyung River in South Korea. We were conducted to field survey for water quality and PPCPs analysis at November, 2006. PPCPs were analyzed by liquid chromatograph coupled with a tandem mass spectrometer (HPLC-MS/MS). The concentration of COD was measured to be 2.37$\sim$19.71 mg/L, which was belong to 4$\sim$5 grade in water quality criteria of lake. Station 2 that there is no pollution in upper stream, was appeared to lower concentration. The concentration of TN and TP, that is cause matter of eutrophication, were found to be 7.78$\sim$35.42 mg/L and 0.08$\sim$0.95 mg/L, respectively, which were exceeding 5 grade in Lake water quality criteria. The 11 kind of PPCPs compounds except levofloxacin and triclosan were detected to Mankyung river. PPCPs concentrations of STP(Sewer Treatment Plant) effluents and aquatic environment in Mankyung river have been detected in the range from dozens of ng/L to hundreds of ${\mu}g/L$ that by order of atenolol, carbamazepine, propranolol, Ibuprofen, erythromycin, ifenprodil, clarithromycin, mefenamic acid, fluconazole, indomethacin, disopyramide. PPCPs concentration of Station 1 and 5, which was influenced by Jeonju STP and Wanju STP, was detected high values. Station 2 that there is no pollution, showed lower values. Station 3 which joined Gosan stream and Jeonju stream and station 4 which influenced by stock wastewater was detected to low values.