• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2008년도 학술발표회 논문집
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• pp.2254-2257
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• 2008

홍수와 가뭄, 수질오염 등의 피해에 대한 대책과 보다 효율적인 수자원 관리를 위해서 원자료에 대한 분석이 선행되어야 한다. 따라서 본 연구에서는 나주지점을 대상으로 하여 총유기탄소(Total Organic Carbon: TOC) 자료와 유출량 자료를 수집하였으며, 각 자료에 대하여 상세한 주기성분을 파악하기 위하여 웨이블렛 변환을 적용하였다. 대상지점으로 선정한 나주지점은 전라남도 나주시 나주대교 상류에 위치하고 있으며, 유역면적이 $2,0587.2km^2$이며, 유로 연장은 65.5km이다. 유출량과 수질자료의 주기성 분석을 위해 유기물의 양을 나타내는 수질지표인 TOC와 나주수위관측소에서 관측된 2003년${\sim}$2004년의 시수위자료를 유출량으로 환산한 값을 사용하였으며, 이 자료의 상세한 주기성 파악을 위해 웨이블렛 변환을 사용하였다. 일반적으로 주기성을 파악하기 위하여 푸리에 변환을 사용하지만, 푸리에 변환은 시간정보와 주파수를 동시에 파악할 수 없을 뿐만 아니라, 자료에 불연속성과 고주파수 성분이 포함될 경우 분석이 난이하다. 이러한 푸리에 변환의 단점을 보안한 것이 웨이블렛 변환이며, 푸리에 변환보다 계산속도가 빠르다. 또한 주어진 자료에 대하여 시간과 주파수 영역에서 동시에 파악하는 것이 가능하며, 불규칙한 자료를 평탄하게 함으로서 보다 상세한 주기성을 찾아낼 수 있다. 따라서 본 연구에서 추출한 각 자료의 상세 주기성분들은 향후 수자원 관리를 위한 기초자료로 활용될 수 있을 것으로 기대된다.

• 한국물환경학회지
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• 제25권5호
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• pp.661-666
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• 2009

In this study, total organic carbon (TOC) and potassium permanganate ($KMnO_4$) demand were examined for raw and finished tap water and the range of $KMnO_4$ demand in drinking water was investigated. By analyzing the relationship between TOC and $KMnO_4$ demand, the applicability of TOC as a drinking water standard and its regulation level was proposed. The average $KMnO_4$ demand was 1.3 mg/L in 4,638 samples from finished drinking water, tap water and finished water from small facilities. $KMnO_4$ demand of 95% of samples was 2.9 mg/L which was 29% of the drinking water standard (10 mg/L). At 12 major drinking water treatment plants, the average $KMnO_4$ demand in July and August was 8.1 and 2.4 mg/L for raw and finished water, respectively. TOC in July and August was 2.0 and 1.15 mg/L for raw and finished water, respectively. The correlation coefficient between $KMnO_4$ demand and TOC was as high as 0.8 in both raw and finished water and $KMnO_4$ demand was twice of TOC in finished water. Because the correlation coefficient and ratio between $KMnO_4$ demand and TOC varied according to season and the characteristics of raw water, it would be difficult to establish TOC standard just from the ratio of $KMnO_4$ demand to TOC. However, it is possible to set the TOC range based on the accumulated $KMnO_4$ demand data or from the satisfactory correlation results. Then, it would be reasonable to establish TOC standard level as 4 ~ 5 mg/L.

• 생태와환경
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• 제56권4호
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• pp.339-347
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• 2023

본 연구는 TOC/TN-IRMS를 이용하여 총 유기탄소 및 총 질소 안정동위원소 분석법을 연구하였으며, 수환경 중저농도 시료에서도 분석이 가능하게 시스템을 구축하였다. 수생태계로 유입되는 다양한 유기탄소 기원을 파악하기 위하여 형광지표와 δ¹³C-DOC 안정동위원소비를 활용한다면 효율적인 수질 관리를 위한 해석기능을 제공할 것이며, 추후 유역 오염원의 대표값(end member)의 지속적인 조사를 통하여 자료구축이 이루어져야 할 것이다.

• Carbon letters
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• 제1권3_4호
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• pp.154-157
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• 2001

Composite adsorbents were prepared by mixing water plant sludge with phenolic resin having the ratio of 1 : 1, 1 : 2, and 1 : 3 respectively, curing from $100^{\circ}C$ to $170^{\circ}C$ under $N_2$ atmosphere, and then activating with $N_2$ at $700^{\circ}C$. Thermal property, specific surface area and morphology of the composite adsorbents as well as their precursors were measured by TGA, BET and SEM respectively. Removal efficiency of the composite adsorbents to ${NH_4}^+$ and TOC was compared with those of commercial zeolite and activated carbon. The adsorbents presented very promising TOC removal efficiency of 98%, which was identical level to that of commercial activated carbon while they displayed removal efficiency, only 32%, of ${NH_4}^+$. Therefore, this composite adsorbent considered as the alternative material of commercial activated carbon, used as an expensive removal agent of organic substances and THM in water treatment plant and it also suggested a possibility of practical application in other processes.

• 한국환경보건학회지
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• 제29권2호
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• pp.1-6
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• 2003

This paper reports on a pilot scale comparison of PACS coagulation with and without pH preadjustment. The pH of the water was adjusted with carbon dioxide and sulfuric acid. Process performance was assessed on the basis of total organic carbon(TOC), UV absorbance, turbidity and disinfection by-product(DBP) precursors. Coagulation pH appeared to be a determining factor for maximum NOM removal. The optimum coagulation pH in order to decrease TOC and turbidity were pH 7. Preadjustment of pH 7 increased TOC removal to as much as 43, 47 percent with sulfuric acid and carbon dioxide. Moreover, coagulation at pH 7 caused a reduction in UV$_{254}$, THMFP and HAAFP compared to the baseline coagulation. For preadjustment of pH 7 with carbon dioxide, the percentage of TOC, UV$_{254}$, THMFP and HAAFP shows the reduction rate of 3.8, 0.5, 4.8, 9.4％ comparing to the coagulation rendition using sulfuric acid. Acid addition to depress pH during coagulation decrease Langelier Saturation Index(LSI), potentially causing increase corrosion in water distribution systems. LSI for carbon dioxide and sulfuric acid at pH 6 was -2.3, -3.3. Therefore, carbon dioxide was more effective at controlling corrosion than sulfuric acid.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제4권2호
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• pp.71-78
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• 2000

The chlorination of municipal drinking water supplies leads to the formation of so-called disinfection by-products(DBPs), many of which have been reported to cause harmful health effects based on animal studies. This study was conducted: 1) to observe seasonal changes in the major DBPs at four sampling sites on a drinking water distribution system located in Chunchon, Kangwon Do; and 2) to examine the effects of major water quality parameters on the formation of DBPs. During the field sampling, the water temperature, pH, and total and free chlorine residuals were all measured. The water samples were then analyzed for total organic carbon(TOC) and eight disinfection by-products in the laboratory. Chloroform, dichloroacetic acid, and trichloroacetic acid were the major constituents of the measured DBPs. The concentrations of the total DBPs were highest in fall, particularly in October, and lowest in summer. The concentrations of the total DBPs increased with increasing TOC concentrations. Multiple regression analyses showed that the concentrations of chloroform, bromodichloromethane, and chloral hydrate were linearly correlated with the pH. Other water parameters were not included in the regression equations. Accordingly, these results suggest that TOC and pH are both important factors in the formation of DBPs.

• 분석과학
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• 제13권2호
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• pp.234-240
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• 2000

수질계의 부식산을 화학적 산화처리하기 위한 방법의 하나로 광산화공정을 도입하여 부식산의 특성 변화를 조사하였다. 광산화공정은 UV단독, UV/$TiO_2$ 및 UV/$H_2O_2$ 시스템을 실험하였다. UV 단독 조사시 TOC 제거율은 pH 7-9에서 가장 높았으며, 흡광도는 강알카리성 영역에서 감소율이 향상된 결과를 보였다. 각 시스템별로 처리도를 보면, UV/$TiO_2$ 시스템의 경우 $TiO_2$ 의 농도가 50ppm 일때 TOC 제거와 흡광도 감소의 효율이 높았으며 50ppm 이상을 투입해도 처리율에 변화가 없었다. UV/$H_2O_2$ 시스템에서는 과산화수소의 농도가 20mM이 최적의 주입농도로 조사되었으며, 그 이상 투입할 경우 TOC와 흡광도의 처리율이 저하되었다. 탄산이온을 첨가할 경우, TOC 제거율 및 UV 흡광도의 감소율 모두 감소하며, TOC 제거율이 흡광도 감소율에 비해 상대적으로 더 크게 나타났다.

• 분석과학
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• 제23권1호
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• pp.36-44
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• 2010

광주지역 하천수와 하수처리장 방류수를 대상으로 유기물 분포 특성과 분해 특성을 파악하고자 하였다. 영산강 수계에서 TOC에서 DOC가 차지하는 비율은 평균 73.9% 정도를 보였다. DOC중 RDOC의 평균 농도는 3.7 mg/L였으며, 비율은 80.9%로 나타나 생분해성유기물에 비해 난분해성유기물의 비율이 높은 것으로 나타났다. 유기물 오염도 지표간 산화율을 비교한 결과 하천수에서는 BOD-C/TOC는 45.0%, $COD_{Mn}$-C/TOC는 63.0%, CODcr-C/TOC는 106.5%로 나타났다. 하수처리장 방류수의 경우는 각각 33.6%, 65.7%, 136.1%로 나타나 하천수에 비해 BOD의 산화율이 낮았다. 하천수 중의 DOC의 평균 분해속도($K_d$)는 영산강 본류에서 $0.042\;day^{-1}$, 지류하천에서 $0.043\;day^{-1}$로 조사되었으며 본류구간과 지류하천간에 유의적인 차이는 없었다(p>0.05). 하수처리장 방류수에서는 $K_d$가 $0.028\;day^{-1}$로 하천수에 비해 낮은 분해속도를 나타냈다.

• 한국환경과학회지
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• 제8권1호
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• pp.101-106
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• 1999

The relationship between primary productivity and changes in water quality was investigated at Mulgum station, a site downstream of the Nakdong River, Korea. Phytoplankton production was characterized by blooms of Microcystis aeruginosa during the summer and Stephanodiscus hantzschii during the winter. Primary production and secondary production by bacterioplankton ranged from 1.5~53.5 mg-C/ι day and 0.1~0.3 mg-C/ι day, respectively. Distribution of total organic carbon appeared to be highly correlated with phytoplankton biomass, especially during blooms of M. aeruginosa, when particulate organic carbon was 81% of total organic carbon and the main source of organic materials supplied into the water. The correlation coefficient between chlorophyll-a and BOD was 0.86. Thus it was concluded that autochthonous phytoplankton mostly affected the BOD level. Total bacterial numbers were also highly correlated with chlorophyll-a ($r^2$= 0.84) and the bacterial community appears to be regulated by phytoplankton biomass in this area.

• 한국물환경학회지
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• 제39권2호
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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.