• Title/Summary/Keyword: COD

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Comparison of Stomach Contents of Pacific Cod (Gadus macrocephalus) in Korean Coastal Waters (우리나라 연안에 서식하는 대구(Gadus macrocephalus)의 위 내용물 비교)

  • Park, Chung Youl;Gwak, Woo Seok
    • Korean Journal of Ichthyology
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    • v.21 no.1
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    • pp.28-37
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    • 2009
  • The diet of Pacific cod (Gadus macrocephalus) in the East Sea, Yellow Sea and Jinhae Bay was studied by analysis of stomach contents. In total, 518 individuals ranging from 15.5 to 77.0 cm standard length SL were analyzed. Prey organisms of the Pacific cod in the East Sea consistedof Caridea, Cephalopoda and Pisces, whereas In the Yellow Sea, the main food items of Pacific cod were similar to those of East Sea Pacific cod except for Cephalopoda. Interestingly, the stomach contents of Pacific cod in Jinhae Bay is mainly Pisces, which is in contrast to those of the two different coastal areas, the East Sea and the Yellow Sea. Although various species of food were eaten by smaller Pacific cod, both Caridea and Pisces were mainly taken by larger Pacific cod. Consequently, the diet of Pacific cod within acertain size is mainly influenced by prey abundance and prey-size spectrum in its habitat. Higher stomach emptiness of Pacific cod in Jinhae Bay might indicate that fully matured Pacific cod temporally stop feeding during their spawning period.

Estimation of a Transport and Distribution of COD using Eco-hydrodynamic Model in Jinhae Bay (생태계 모델을 이용한 진해만의 COD의 거동과 분포특성 평가)

  • Hong, Sok-Jin;Lee, Won-Chan;Jung, Rae-Hong;Park, Sung-Eun;Jang, Ju-Hyung;Kim, Hyung-Chul;Kim, Dong-Myung
    • Journal of Environmental Science International
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    • v.16 no.12
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    • pp.1369-1382
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    • 2007
  • To find proper water quality management strategy for oxygen consumption organic matters in Jinhae bay, the physical process and net supply/decomposition in terms of COD was estimated by three-dimensional eco-hydrodynamic modeling. The estimation results of physical process in terms of COD showed that transportation of COD was dominant in loading area from land to sea, while accumulation of COD was dominant in $middle{\sim}bottom$ level. In case of surface level, the net supply rate of COD was $0{\sim}60\;mg/m^2/day$. The net decomposition rate of COD was $0{\sim}-0.05\;mg/m^2/day$($-5{\sim}-10$ m, in depth) to 2 level, and $-0.05{\sim}-0.20\;mg/m^2/day(10m{\sim})$ to bottom level. These results indicate that the biological decomposition and physical accumulation of COD are occurred for the most part of Jinhae Bay bottom. The variation of net supply or net decomposition rate of COD as reducing land based input loading is also remarkable. Therefore, it is important to consider both allochthonous and autochthonous oxygen demanding organic matters to improve the water quality of Jinhae Bay.

Enhanced and Balanced Microalgal Wastewater Treatment (COD, N, and P) by Interval Inoculation of Activated Sludge

  • Lee, Sang-Ah;Lee, Nakyeong;Oh, Hee-Mock;Ahn, Chi-Yong
    • Journal of Microbiology and Biotechnology
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    • v.29 no.9
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    • pp.1434-1443
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    • 2019
  • Although chemical oxygen demand (COD) is an important issue for wastewater treatment, COD reduction with microalgae has been less studied compared to nitrogen or phosphorus removal. COD removal is not efficient in conventional wastewater treatment using microalgae, because the algae release organic compounds, thereby finally increasing the COD level. This study focused on enhancing COD removal and meeting the effluent standard for discharge by optimizing sludge inoculation timing, which was an important factor in forming a desirable algae/bacteria consortium for more efficient COD removal and higher biomass productivity. Activated sludge has been added to reduce COD in many studies, but its inoculation was done at the start of cultivation. However, when the sludge was added after 3 days of cultivation, at which point the COD concentration started to increase again, the algal growth and biomass productivity were higher than those of the initial sludge inoculation and control (without sludge). Algal and bacterial cell numbers measured by qPCR were also higher with sludge inoculation at 3 days later. In a semi-continuous cultivation system, a hydraulic retention time of 5 days with sludge inoculation resulted in the highest biomass productivity and N/P removal. This study achieved a further improved COD removal than the conventional microalgal wastewater treatment, by introducing bacteria in activated sludge at optimized timing.

Estimation of TOC Concentration using BOD, COD in Runoff from Paddy Fields (영농기간동안 논 유출수 BOD, COD 자료를 이용한 TOC 농도 추정)

  • Choi, Dongho;Jung, Jaewoon;Yoon, Kwangsik;Lee, Kyoungsook;Choi, Woojung;Lim, Sangsun;Park, Hana;Yim, Byungjin;Hwang, Taehee
    • Journal of Korean Society on Water Environment
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    • v.28 no.6
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    • pp.813-818
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    • 2012
  • BOD and COD are currently used for water quality indices, but adoption of TOC for TMDL (Total Maximum Daily Load) is being suggested. Estimation of TOC using existing BOD and COD data is very important to diagnosis water quality trend when TOC is used for water quality index of organic matter in the future. The relationships between BOD COD and TOC in runoff from paddy fields were investigated during 2008-2011. The observed mean concentration of EMCs (Event Mean Concentration) for BOD, COD, TOC were 3.87, 10.97, 7.26 mg/L respectively. The correlation coefficients between BOD-TOC and COD-TOC were 0.42, 0.73, respectively. The coefficient of determination of regression equation for BOD-TOC and COD-TOC were 0.18, 0.53 respectively. Even though, conversion of COD data to TOC seems to be rather reliable than that of BOD-TOC, further monitoring is recommended to ensure better interpretation of relationship among BOD, COD and TOC.

A Suitable Dichromate Reflux Method for the Analysis of Chlorous Wastewater (COD 분석시 염소이온의 간섭작용에 관한 연구)

  • 김종규;김남천;민달기
    • Journal of Environmental Health Sciences
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    • v.15 no.2
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    • pp.33-40
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    • 1989
  • Dichromate reflux method for COD analysis is one of the useful and precise way to solve the organic content of the wastewater. But the standard procedure for COD is not entirely satisfactory for sample containing appreciable amounts of inhibiting substance, especially chloride ion. Under the conditions of the established test, a big disadvantage of the method is that dichromate oxidizes chloride quantitatively to chlorine. When it is necessary to use silver sulfate as a catalyst in the COD procedure, chloride must be removed before the addition of the catalyst. Silver sulfate and mecuric sulfate forms a precipitate of AgCl and HgCl$_{2}$ separately which is not completely oxidized during the test and, therefore, cannot be corrected for. So, we evaluate and compensate the amount of chloride oxidation in the absence of chemicals during the experimental procedure. Calculation of COD is made using the following reviced formula: real COD = tested COD - 0.2277Cl.

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Analysis of Economical Validity about Offshore Cage Culture for Cod (외해 가두리 대구 양식업 경제적 타당성 분석)

  • LEE, Kwang-Nam
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.6
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    • pp.1724-1738
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    • 2016
  • This paper was researched on economic feasibility and sensibility of operation to offshore cage culture for cod. Offshore cage culture for cod needs to invest high budget what to construction and operation. And it was required variety methods about analysis of economic feasibility. Therefore, these were studied NPV, B/C and sensitivity for each by assuming a six scenarios considering the product performance according to the size of cod and culturing methods of fingerlings, etc. As a results, even though economy, if efficiency is low, it is a priority need the technical development to promote the feed efficiency to increase economic feasibility and should make efforts to enhance the business economy to strengthen the price competitiveness pricing with high quality products through quality control and brand recognition of cod. It expects to be used as a reference for related research in the future by deriving policy implications based on the method of analysis of the economic feasibility on offshore cage culture for cod.

Organic Characteristic of Piggery Wastewater and Kinetic Estimation in Biofilm Reactor (생물막 반응조에서 돈사폐수의 유기물 특성 및 동력학계수 산정)

  • Rim, Jay-Myoung;Han, Dong-Joon;Kwon, Jae-Hyuk
    • Journal of Industrial Technology
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    • v.16
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    • pp.51-60
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    • 1996
  • This research was performed for the fundamental data using a advanced treatment process of piggery wastewater. Characteristics of influent wastewater was divided with various methods in fixed biofilm batch reasctor. Fractons of organic were divided into readily biodegradable soluble COD(Ss), slowly biodegradable COD(Xs), nonbiodegradable soluble COD($S_I$), and nonbiodegradable suspended COD($X_I$). Experimental results were summerized as following : i) biodegradable organics fraction in piggery wastewater was about 88.1 percent, and fraction of readily biodegradable soluble COD was about 66.1 percent. ii) Fractions of nonbiodegradable soluble COD was 11~12 percent, and soluble inert COD by metabolism was producted about 6~8 percent. iii) Active biomass fraction of attached biofilm was about 54.7 percent, and substrate utilization rate and maximum specific growth rate of heterotrophs were $8.315d^{-1}$ and $3.823d^{-1}$, respectively.

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A Study on the Appropriateness as Organic Matters Indicator and the Distribution of Chemical Oxygen Demand and Total Organic Carbon in Masan Bay, Korea (마산만 해수 중 화학적산소요구량과 총유기탄소 분포 특성 및 유기물 지표로서의 적절성 검토)

  • PARK, MI-OK;LEE, YONG-WOO;CHO, SEONG-AH;KIM, HYE-MI;PARK, JUN-KUN;KIM, SUNG-GIL;KIM, SEONG-SOO;LEE, SUK MO
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.26 no.2
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    • pp.82-95
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    • 2021
  • We investigated the temporal and spatial distribution characteristics of chemical oxygen demand (COD) and total organic carbon (TOC) in all 13 locations of Masan Bay from February to November in 2015. The COD and TOC contents were high during the June-August period when the pollution load increased. In particular, the concentrations of COD and TOC were about twice as high in the surface water as in the bottom water. In spatial distribution, the COD and TOC concentrations at the inner bay were about twice as high as those of the outer bay in Masan Bay. As a result of estimating the oxidation efficiency of COD from the surface layer of Masan Bay in 2015 based on the theoretical oxygen demand (TOD), it was at the level of about 23%. Due to the low oxidation efficiency of COD, there is a risk that the organic matter in Masan Bay will be somewhat underestimated. Therefore, for quantitative analysis of organic matter, COD and TOC analyses need to be combined.

The State and Sources of Contamination with BOD, COD, T-N and T-P in Stream Within Chonju City (전주시 하천의 BOD, COD,총질소, 총인에 대한 수질현황 및 오염원)

  • 오창환;이지선;김강주;황갑수
    • Economic and Environmental Geology
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    • v.35 no.1
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    • pp.43-54
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    • 2002
  • The Chonju and Samchun streams are palling though Chonju City and several contamination sources are located along these streams. The Samchun stream joins the Chonju stream in the Gosapyeong waste disposal site and the Chonju stream finally joint to the Mankyeong River. The Chonju and Samchun streams are now contaminated with BOD, COD, T-N and T-P and the amounts of each contamination are increasing from upper stream to downstream. At the downstream the amounts of COD. T-N.T-P are several times higher than fifth grade of water quality thor lacustrine. Sewage from Chonju provides BOD, COD,T-N and T-P into the Chonju and Samchun streams and Chonju Waste Water Treatment Plant il a main source of COD, T-N and T-P contamination. Gosapyeong waste disposal site may be the source of BOD and COD contamination. T-N is higher than fifth grade of water quality for lacustrine at the upper stream indicationg that the rivers are contaminated with T-N before inflowing into Chonju by agricultural activity. The Chonju stream asffects the contamination of the Mankyeong river with BOD. COD, T-N,T-P. Other branch steams of the Mankyeong river also affects the contamination of the Mankyeong river by BOD, COD, T-N and T-P, Among the branch streams, the Ikasn stream is a main contamination source. Amounts of concentrations inflowing from the Chonju and Sanchun Streams on Aug. 1999 are calculated by using yeasured flow rate find concentrations of contaminants The result are as fikkiws; 1) the amounts of influent from the Gosan Stream are 0.49, 0.86, 1.61 and 0.01 ton/day for BOD, COD, T-N and T-P, respectively, 2) compared to the amounts of influent from the Gosan Stream, BOD, COD,T-N,T-P supplied from the Chonju river are higher by about 5, 7, 7. 36 times, respectively, and those supplied from the Iksan stream are higher by about 13, 10, 10, 147 times, respectively.

Performance Evaluation of Anaerobic Bioreactors in Treating Swine Wastewater (양돈폐수 처리를 위한 혐기성 생물반응기의 성능 비교)

  • Kim, Jong-Soo;Lee, Gook-Hee;Sa, Tongmin
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.11
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    • pp.2047-2058
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    • 2000
  • The effects of operating parameters on performance of upflow anaerobic sludge blanket(UASB). anaerobic filter(AF), and two-stage anaerobic sludge bed filter (ASBF) bioreactors in treating swine wastewater were evaluated by operating the lab-scale bioreactors upto hydraulic retention time(HRT) of 1 day and organic loading rate (OLR) of $5.1kg-COD/m^3{\cdot}d$ for 200 days. Swine wastewaters of which characteristics were affected by types of hog raising and seasons contained high concentrations of COD, SS, and ammonia. Inoculation of the bioreactors with waste sludge from anaerobic treatment facility of local municipal wastewater treatment plant was effective in developing biomass in the bioreactors. Acclimation period of the bioreactors with swine wastewaters required approximately 40 days, but that for AF and two-stage ASBF, which were filled with media, was faster than VASB. The bioreactors showed high and stable COD removal efficiency of 77~91% at influent T-N concentrations of 370~800mg/L but low and unstable COD removal efficiency of 24~94% at influent T-N concentrations of 760~1,310mg/L. It is essential to remove ammonia prior to anaerobic treatment since the concentrations of ammonia in swine wastewaters showed toxic effects to methanogenic bacteria. The bioreactors were effective in treating swine wastewaters with COD removal efficiency of 78.9~81.5% and biogas generation rate of $0.39{\sim}0.59m^3/kg-COD_r$ at OLR of $1.1{\sim}2.2kg-COD/m^3{\cdot}d$: however, an increase of OLR by reducing HRT and increasing influent COD caused decrease of COD removal efficiency. The extent of decrease in COD removal efficiency was higher in UASB than AF and two-stage ASBF. AF and two-stage ASBF anaerobic bioreactors were effective in treating varing characteristics of swine wastewaters since they showed high and stable COD removal efficiency at high OLR due to effective retention of biomass by media and staging.

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