• Title/Summary/Keyword: DOC

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Study on Removal of DOC for Effluent from Nitrification and Denitrification Process with Zeolite by Combined Process of Coagulation and UF Membrane (제올라이트를 첨가한 질산화 탈질공정에서 응집과 UF공정을 이용한 처리수내 용존 유기물질 제거 연구)

  • Han, Jang Hyuk;Yoon, Tai Il;Cho, Kyung Chul;Song, Jea Yong
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.5
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    • pp.537-546
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    • 2005
  • This study was carried out to evaluate EPS and SMP variation of sludge and effluent in nitrification and denitrification process with zeolite addition, a possible reduction of effluent DOC by URC(Ultra Rapid Coagulation) process. As a biological wastewater treatment result, EPS formation of both aeration and anoxic sludges are not affect by SRT variation. However, EPS concentration of sludges is higher in aeration tank than in anoxic tank by 6~8 mg EPS/ g VSS. Linear relationship between SMP to DOC indicates that SMP of bulk solution contributes to most of the biological treatment effluent DOC. DOC and turbidity removal efficiency was more improved with URC process than in a conventional coagulation. For pretreatment of UF filtration DOC removal was advanced by URC process than only UF filtration.

Removal of Odor and THM from the Raw Water of Daecheong Dam (대청호 원수내 냄새 및 THM 제거방안 연구)

  • Jeon, Hang-Bae;Yun, Gi-Sik
    • Journal of Korea Water Resources Association
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    • v.30 no.3
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    • pp.235-245
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    • 1997
  • A pilot scale study for removing odor and trihalomethane formation potential (THMFP) was investigated in the standard water treatment plant equipped with ozone oxidation and granular activated carbon (GAC) adsorption processes. The removal efficiency of dissolved organic carbon (DOC) in the pilot scale standard water treatment process (PSWTP) was about 25%, however, no more removal in the ozone oxidation process. On a GAC after 30 days operation, DOC removal efficiency was about 75%. Odor removal efficiency was about 30% in PSWTP, 60% in ozone oxidation, and almost complete in well as DOC. Mid-1 and 2 that showed breakthrough in odor inducing material as well as DOC. Mid-1 and 2 chlorination was able to reduce trihalomethanes (THM) by 25% compared to prechloringation, while postchlorination alone could reduce them by 30%.

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A Study of Unregulated Emission Reduction Characteristics by Diesel Oxidation Catalyst (DOC) for Light-Duty Diesel Engine (소형디젤엔진용 산화촉매에 의한 미 규제 배출가스 저감특성에 관한 연구)

  • Kim, Ki-Ho;Ahn, Gyun-Jae;Kang, Keum-Won;Lee, Seang-Wock;Eom, Dong-Seop;Lee, Tae-Young
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.2
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    • pp.145-150
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    • 2006
  • Recently emission regulation on diesel vehicles is getting stringent and research on aftertreatment technology such as DPF and DOC has been carried out actively. Even though PM(Particulate matters) reduction efficiency in DOC is relatively low but the structure is simpler and very effective in the reduction of gas materials and unregulated materials. Therefore it has been applied to smaller diesel vehicles. The aims of this research is to investigate the emission reduction characteristics of DOC; DOC performance of regulated and unregulated material emission reduction. It results a Pt based catalyst demonstrated higher emission reduction efficiency than a Pt-V based catalyst in CVS-75 mode, and also the reduction efficiency of unidentified material was excellent.

A Critical Review for the Effect of Ozonation on Biodegradability in Drinking Water Treatment Systems (전오존처리에 의한 상수원수의 생물학적 처리효율제고에 관한 연구)

  • Nam, Sang-Ho
    • 수도
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    • v.24 no.4 s.85
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    • pp.79-87
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    • 1997
  • In an effort to prevent the formation of DBPs from disinfection and the microbial regrowth in distribution systems, the ozonation followed by biological filtration process in drinking water treatment train has been recently developed as an alternative process to reduce effectively water-born organic matter as precursor. There are, however, insufficient for the consistent information and data about the relation between ozone dosage based on organic surrogate parameter, TOC or DOC and effect of ozonation on BDOC formation. This study is to review critically for the effect of ozonation on biodegradability on the basis of published technical papers including the output from author's research laboratory. It truned out that : 1. ozonation in the presence of organic matter has a tendancy to increase in BDOC content, 2. the rate of BDOC formation was maximum below 1mg $O_3/mg$ DOC of ozone dose, but about maximum content of BDOC was obtainable at the range from 1.5mg $O_3/mg$ DOC to 2mg $O_3/mg$ DOC, 3. from above 1mg $O_3/mg$ DOC, the rate of BDOC formation became slow down, 4. from above 2mg $O_3/mg$ DOC, BDOC formation was quantitatively negligible, In conclusion, it needs further systematic study and research concerned to biodegradability and treatability by ozonation in terms of organic characteristics and experimental conditions because it was hard to find out the consistent experimental data comparable each other that were performed by numbers of research authors.

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The Effect of an Oxidation Precatalyst on the $NO_x$ Reduction by $NH_3$-SCR Process in Diesel Exhaust ($NH_3$-SCR 방법에 의한 디젤 배기 내 De-$NO_x$ 과정에서의 DOC에 의한 영향과 저감 성능 변화)

  • Jung, Seung-Chai;Yoon, Woong-Sup
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.5
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    • pp.68-76
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    • 2008
  • Diesel $NO_x$ reduction by $NH_3$-SCR in conjunction with the effective oxidation precatalyst was analytically investigated. Physicochemical processes in regard to $NH_3$-SCR $NO_x$ reduction and catalytic NO-$NO_2$ conversion are formulated with detailed descriptions on the commanding reactions. A unified model is correctly validated with experimental data in terms of extents of $NO_x$ reduction by SCR and NO-$NO_2$ conversion by DOC. The present deterministic model based on the rate expressions of Langmuir-Hinshelwood reaction scheme finds a conversion extent directly. A series of numerical experiments concomitant with parametric analysis of the $NO_x$ reduction was conducted. $NO_x$ reduction is promoted in proportion to DOC volume ar lower temperatures and an opposite holds at lower space velocity and intermediate temperatures. $NO_x$ conversion is weakly correlated to the space velocity and the DOC volume at higher exhaust temperature. In DOC-SCR system, the $NO_x$ reduction efficiency depends on the $NH_3/NO_x$ ratio.

A Study on the Biodegradability and Characteristics Based on Apparent Molecular Weight Distribution of Dissolved Organic Matter in Sewage (하수중 용존 유기물의 생분해도 및 분자량 분포에 따른 거동특성에 관한연구)

  • 최정헌;이윤진;명복태;우달식;이운기;남상호
    • Journal of Environmental Health Sciences
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    • v.27 no.2
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    • pp.92-99
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    • 2001
  • This present study was aimed to investigate the characteristics of dissoloved organic matter (DOC) in sewage. The results are summarized as follows ; The plateaux reached in 3~4 days by the biodegradability test on sewage samples based on DOC. 쏭 rations of BDOC to DOC were 48, 21, 13 and 11% for raw sewage, primary treatment effluent, secondary treatment effluent and final treatment effluent, respectively. As the SUVA values ranged less 3L/m.mg for the effluent of sewage treatment plant, the DOC is composed largely of non-humic materials, hydrophilic, less aromatic as compared to waters with higher SUVA values. Through the biodegradability test, Dissolved organics showed that the quantity of LMW(Low Molecular Weight) less than 1,000 daltons was decreased, HMW(High Molecular Weight) more than 30,000 daltons had a tendency to increase. Large portion of UV$^{254}$ in final treatment effluent was increased of MMW(Medium Molecular Weight). Also, average removal efficiency of DOC was 32% during sewage treatment.

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Development of Regression Models for Estimation of Unmeasured Dissolved Organic Carbon Concentrations in Mixed Land-use Watersheds (복합토지이용 유역의 수질 관리를 위한 미측정 용존유기탄소 농도 추정)

  • Min Kyeong Park;Jin a Beom;Minhyuk Jeung;Ji Yeon Jeong;Kwang Sik Yoon
    • Journal of Korean Society on Water Environment
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    • v.39 no.2
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    • pp.162-174
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    • 2023
  • In order to prevent water pollution caused by organic matter, Total Organic Carbon(TOC) has been adopted indicator and monitored. TOC can be divided into Dissolved Organic Carbon(DOC) and Particulate Organic Carbon(POC). POC is largely precipitated and removed during stream flow, which making DOC environmentally significant. However, there are lack of studies to define spatio-temporal distributions of DOC in stream affected by various land use. Therefore, it is necessary to estimate the past DOC concentration using other water quality indicators to evaluate status of watershed management. In this study, DOC was estimated by correlation and regression analysis using three different organic matter indicators monitored in mixed land-use watersheds. The results of correlation analysis showed that DOC has the highest correlation with TOC. Based on the results of the correlation analysis, the single- and multiple-regression models were developed using Biochemical Oxygen Demand(BOD), Chemical Oxygen Demand(COD), and TOC. The results of the prediction accuracy for three different regression models showed that the single-regression model with TOC was better than those of the other multiple-regression models. The trend analysis using extended average concentration DOC data shows that DOC tends to decrease reflecting watershed management. This study could contribute to assessment and management of organic water pollution in mixed land-use watershed by suggesting methods for assessment of unmeasured DOC concentration.

Characteristics of Changes in DOC Concentration according to Concentrations of Organic Matter and Suspended Solids in the Nakdong River (낙동강에서 유기오염 및 SS 농도 변화에 따른 DOC 농도 변화의 특성)

  • Lee, Kyu-Yeol;Kim, Ju-Eon;Lee, Kwon-Chul;Lee, Kyung-Lak;Lee, In-Jung;Im, Tae-Hyo
    • Journal of Korean Society on Water Environment
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    • v.29 no.4
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    • pp.540-550
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    • 2013
  • Temporal increase of SS induces concentrations in various forms of organic matter including BOD, COD, TOC. Consequently, it causes hard to identify sources of water pollution during or after precipitation. The objective of this study is to investigate variations of DOC concentration caused by increase of flow and changes of external factors in river by comparing to SS concentration. In results, monitoring sites (e.g., Banbyeonchen) consisting of hard riverbed showed high correlation between SS and organic matters, except BOD. On the contrary, other sites (e.g., Naesungcheon) where riverbed consists of sand were found in a wide range of annual fluctuation in SS level, whereas these sites showed a narrow range in annual DOC fluctuation. In Gumhogang and Namgang, a lower correlation between SS and other factors was found most likely because of high concentration in organic matter. However, lower annual fluctuation values of DOC were observed in comparison to those of COD and TOC. Similar results were also confirmed in main river sites, Sangju and Mulgeum. In conclusion, DOC concentration is better indicator for monitoring organic matter which cannot be provided by BOD, COD, TOC in the Nakdong river basin.

Characteristics of TOC Distribution in Lake Hapcheon (합천호의 TOC 분포 특성)

  • Seong, Jin-Uk;Kim, Hyung-Jin;Park, Jae-Chul
    • Journal of Environmental Science International
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    • v.20 no.6
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    • pp.711-719
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    • 2011
  • This study was conducted to estimate the distribution characteristics and budget of organic matter in the Lake Hapcheon. In the dry season, the concentration ranges of organic carbons were similar, but in the rainfall season, it showed about double concentrations. Changes of vertical water quality in the lake, there were no big differences with the concentration by the depth. However, it tends to be relatively high on the surface, a little low on the mid-depth and high in the lake bottom. DOC rate at TOC, it was lower than POC rate at inflow and DOC rate was higher than POC rate in the lake and discharging water. R-DOC accounted for more 80% of DOC rate in all investigated areas, therefore we judge that this R-DOC is to increase the organic carbon pollution gradually. As the result of the calculated organic carbon budget in the Lake Hapcheon, the amount of allochthonous, autochthonous and release were 3,552, 3,288, 228 tonC/year, respectively. the amount of discharge, decomposition and sedimentation were 504, 1,344, 5,520 tonC/year, respectively. According to this investigation, the changed amount of organic matter in the Lake Hapcheon recorded -300 tonC/year with the increase of 7,068 tonC/year and the decrease of 7,368 tonC/year.

The Distribution of POC and DOC in Four Reservoirs on the North Han River and the Relationship with Algal Density (북한강수계 호수의 POC와 DOC 분포와 조류밀도의 관계)

  • Kim, Kiyong;Kim, Bomchul;Eom, Jaesung;Choi, Youngsoon;Jang, Changwon;Park, Hae-kyung
    • Journal of Korean Society on Water Environment
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    • v.25 no.6
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    • pp.840-848
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    • 2009
  • Spatial and temporal distributions of POC and DOC were surveyed in the North Han River system, Korea The proportion of algal cells was calculated in four reservoirs (Lakes Soyang, Paro, Chunchon, and Uiam). Monthly average DOC concentrations ranged from 1.5 to 2.3 mg C/L, and POC showed larger variation than DOC (range 0.3 to 1.9 mg C/L). The average proportion of POC in TOC was higher than those of typical natural lakes. Due to the influence of the Asian summer monsoon, the seasonal variation in POC concentration depended on heavy rain events occurring during the summer. POC concentrations increased during the summer monsoon season due to turbid storm runoff laden with debris, while DOC concentrations did not increase. The highest POC concentrations were observed in Lake Soyang in 2006 when a severe rain event occurred. In two deep stratified reservoirs (Lake Soyang and Paro) storm runoffs formed an intermediate turbidity layer with high POC and chlorophyll concentrations which is thought to originate from terrestrial debris and periphyton transported by inflowing streams. The proportion of algal cells in total POC was much lower than for most natural lakes, and it varied with season; low in the monsoon season and high in dry seasons with algal blooms. An analysis of POC concentration and chlorophyll a concentration showed that the ratio of POC/Chl.a varied from 24 to 80.