• 한국물환경학회지
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• 제20권4호
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• pp.357-364
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• 2004

In this study, biodegradable organic matter was divided into a rapidly biodegradable fraction($BDOC_{rapid}$) and a slowly biodegradable fraction($BDOC_{slow}$) for various waters with different types of DOC. These fractions($BDOC_{rapid}$ and $BDOC_{slow}$) were defined by using a shaking incubation method modified from Carlson's method. Also, in this study, optimum incubation time and accuracy were investigated to determine $BDOC_{rapid}$ and $BDOC_{slow}$. When suspended bacteria obtained from raw water and BAC effluent, or attached bacteria from BAC was respectively used as an inoculum, the difference in total BDOC($BDOC_{total}$) was minimal. Therefore, total BDOC was determined in 7~8 days by the shaking method, which is comparable with Servais's method by which BDOC was determined in 28 days. In addition, the difference of BDOC between these two methods was within 7%. Although $BDOC_{rapid}$ and $BDOC_{slow}$ were effectively determined by a method defined by Klevens, the difference in optimal incubation time was significant for different water samples. However, when using the shaking method, optimal incubation time for $BDOC_{rapid}$ was found to be 3 days, therefore, the $BDOC_{rapid}$ was defined as the difference between $DOC_0$ and $DOC_{3days}$, and $BDOC_{slow}$ was defined as the difference between $BDOC_{total}$ and $BDOC_{rapid}$. As a conclusion, for determining the fraction of BDOC using the shaking method, the concentrations of an inoculurns and optimal incubation times used in this study were very effective.

• 대한환경공학회지
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• 제28권12호
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• pp.1274-1279
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• 2006

본 연구에서는 낙동강 하류 매리원수, 부산시 회동수원지 원수 및 매리원수를 정수처리하는 pilot-plant의 급속 모래여과 처리수를 이용하여 오존 투입농도별로 $BDOC_{rapid}$4와 $BDOC_{slow}$의 생성특성에 대하여 조사하였다. $BDOC_{total}$ 농도가 최대가 되는 오존 투입 농도는 매리원수, 회동원수 및 모래여과 처리수에서 각각 0.9, 1.1 및 1.4 $mgO_3/mgDOC$로 조사되어 실험에 사용된 시료수의 특성에 따라 $BDOC_{total}$이 최대로 생성되는 오존 투입농도는 다르게 나타났다. $BDOC_{rapid}$를 최대로 생성시키는 오존 투입농도는 $BDOC_{total}$을 최대로 생성시키는 오존 투입농도 보다 낮은 $0.9{\sim}1.1\;mgO_3$/mgDOC로 나타났으며, 1 $mgO_3$/mgDOC 이상의 오존 투입농도에서는 $BDOC_{rapid}$의 농도가 오하려 낮아지는 것으로 나타났다. 또한. 오존 처리에 따른 $BDOC_{slow}$의 생성특성 조사에서 $BDOC_{slow}$는 $BDOC_{total}$과 $BDOC_{rapid}$를 최대로 생성시키는 오존 투입농도 보다 더 높은 오존 투입농도에서도 지속적으로 생성되었다. Biofiltration 공정의 전처리로 사용되는 오존의 최적 투입량을 결정할 수 있는 $BDOC_{rapid}/BDOC_{total}$비를 실험에 사용된 시료수별로 조사한 결과 $0.6{\sim}1.0\;mgO_3$/mgDOC로 조사되어 $BDOC_{total}$이 최대로 생성되는 오존 투입농도 $0.9{\sim}1.4\;mgO_3$/mgDOC보다 낮은 것으로 나타났다. 따라서 최적의 오존 투입율 결정시 BDOC 분류를 통한 접근법이 경제성 측면이나 biofiltration 공정의 효율면에서도 훨씬 효율적인 것으로 조사되었다.

• 대한환경공학회지
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• 제31권10호
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• pp.909-918
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• 2009

급수시스템에서 박테리아 재성장의 영양원이 되는 DOC를 정수처리 공정에서 효과적으로 저감시키기 위하여 생분해와 흡착으로 구분하여 네 종류의 DOC로 분획하였고 각각의 제거특성을 연구하였다. 네 종류의 분획 DOC는 흡착성을 가지면서 생분해성이 없는 AnBDOC, 흡착성이 없고 생분해성만이 있는 nABDOC, 흡착과 생분해성을 동시에 나타내는 ABDOC, 흡착과 생분해가 되지 않는 nAnBDOC로 구분하여 분석하였다. 낙동강 중류에 위치한 정수처리장 원수의 조사결과, ADOC가 BDOC보다 약간 높은 비율로 존재하고 있으며, 오존산화 후에는 분획 DOC 중에서 AnBDOC 농도가 가장 많이 제거되었으며, 제거율은 nAnBDOC가 49.5%로 가장 높았다. BAC 공정으로 제거된 분획 DOC 중에는 ADOC가 약 91%를 차지하고 있으므로 흡착에 의한 제거가 우수한 것으로 나타났고, 잔류하는 TDOC 0.50 mg/L 중에는 ADOC가 0.46 mg/L(67.7%)을 차지하고 있으므로 배수관내 미생물 증식 및 소독부생성물의 생성 방지를 위하여 BAC 공정상에서 EBCT증가, 재생주기 등의 운전조건을 개선해야 하는 것으로 나타났다. 정수처리 공정에서 DOC분획 결과로부터 흡착이나 생분해 등으로 제거 가능량을 파악할 수 있으므로 정수처리 공정에 유용한 것으로 나타났다. 염소처리하는 정수처리 공정에서 DOC분획 농도와 밀접한 관계를 가지는 AOX의 분석결과, AOX 7.1 ${\mu}g$/L은 오존산화와 활성탄흡착 공정으로 0.51 ${\mu}g$/L까지 충분히 제거되었다.

• 환경위생공학
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• 제16권3호
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• pp.34-41
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• 2001

It is well known that bioassay on the low organic matters in water have developed from the two methods. One is assimilable organic carbon(AOC) that makes use of the maximum growth biomass of the pure strains for the standard substrates, the other is biodegradable dissolved organic carbon(BDOC) that determines the fraction of dissolved organic carbon(DOC) available for microbial utilization. The purpose of this study was to upgrade the measurement method of BDOC in natural water or drinking water. BBOC was determined by means of the bacterial growth and the DOC decrease at the same time. The origin inoculums were used to the suspended bacteria from Han River water, The initial optimum biomass and incubation time for initial DOC were induced by variation of nutrient repression and inoculums. The time reached to minimum DOC was selected as incubation time. The initial optimum biomass for Han river water was about 1000~5000 CFU/mL, respectively. In a sufficient biomass, suitable incubation time was about 3~5 day. It was indirectly calculated BDOC on maximum growth rate by measuring growth yield of indigenous bacteria. But it was difficult to adapt growth yield coefficient because of irregular bacterial growth. The measured 3 day BDOC was close to BDOC calculated with our proposed experimental equation between DOC and BDOC. It shows that the quantification of BDOC with this experimental equation can be used indirectly.

• 수도
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• 제24권4호통권85호
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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.

• 상하수도학회지
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• 제12권3호
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• pp.21-29
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• 1998

The ozone/GAC process, sometimes termed BAC(Biological Activated Carbon) appeared to be effective for the removal of soluble organic matters in the drinking water Chabrol is a simple model for the simulation like as the variation of HPC and BDOC in the BAC tower. This study were carried out to calibrate of HPC and BDOC and to evaluate $H_1$ and $H_2$ of ozone-treated water with Chabrol model. BDOC values of the ozone-treated water and BAC effluent are analyzed using method of Levi and Joret. As the ozone-treated water and BAC Effluent are incubated, the HPC are increased up to 0.24 mgC/l and 0.09 mgC/l respectively. $H_1$ and $H_2$ of the ozone-treated water is 0.3 mgC/l and 0.349 mgC/l respectively and Chabrol model for BAC tower can be calibrated.

• 환경위생공학
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• 제13권1호
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• pp.166-173
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• 1998

This study was to investigate the effects of preozonation on the waterborne organic removal by the biologically active GAC fluidized bed on a laboratory scale. The raw water to be treated comes from midstream of Han river. As the ozone dose was increased in the range of $1~3{;\}mgO_{3}/mgDOC$, it produced BDOC from 1.82 to 2.65 times. And BDOC formation can be expressed as [BDOC] = 0.74 + 0.21[DOC] ($R^{2}{\;}={\;}0.8399$). The effects of combination of ozonation followed by BACFB (Biological Activated Carbon Fluidized Bed) process were analyzed. At the ozone doze of $1~3{\;}mgO_{3}/mgDOC$, the large fraction of BDOC was removed by BACFB, but parameter revealed only around 10% reduction.

• 대한환경공학회지
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• 제29권2호
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• pp.205-213
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• 2007

입상활성탄 및 생물여과 공정에서 활성탄 종류별 DOC(dissolved organic carbon) 흡착능은 석탄계가 가장 우수한 것으로 나타났고, 다음으로 야자계, 목탄계 순으로 조사되었으며, 활성탄 종류별 부착 미생물의 생체량과 활성도는 석탄계에서 가장 높게 나타났으며, 다음으로 목탄계, 야자계, 안트라사이트 순으로 나타났다. 안트라사이트를 이용한 생물여과 공정에서 OM(natural organic matters)의 생분해율은 15분 이상의 EBCT(empty bed contact time)가 주어져야 bed volume에 따라 평균 $10\sim17%$, 최대 $18\sim24%$ 정도의 생분해율을 얻을 수 있었다. NOM의 활성탄 흡착은 주로 친수성 보다 소수성 유기물질과 10,000 Da 이하의 유기물질의 제거가 용이하였으며 HAA5FP(haloacetic acid 5 formation potential) 보다 THMFP(trihalomethane formation potential), BDOC(biodegradable dissolved organic carbon)$_{rapid}$ 보다는 $BDOC_{slow}$의 제거가 용이한 것으로 조사되었다. 생물여과 공정에 의한 유기물질 제거 특성은 주로 친수성과 1,000 Da 이하의 유기물질 제거가 용이하였으며, THMFP 보다는 HAASFP, $BDOC_{slow}$ 보다는 $BDOC_{rapid}$의 제거가 용이한 것으로 조사되었다.

• 상하수도학회지
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• 제32권2호
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• pp.159-168
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• 2018

Climate change is believed to increase the amount of dissolved organic matter in surface water, as a result of the release of bulk organic matter, which make difficult to achieve a high quality of drinking water via conventional water treatment techniques. Therefore, the natural water treatment techniques, such as managed aquifer recharge (MAR), can be proposed as a alternative method to improve water quality greatly. Removal of bulk organic matter using managed aquifer recharge system is mainly achieved by biodegradation. Biodegradable dissolved organic carbon (BDOC) and assimilable organic carbon (AOC) can be used as water quality indicators for biological stability of drinking water. In this study, we compared the change of BDOC and AOC with respect to pretreatment methods (i.e., ozone or peroxone). The oxidative pretreatment can transform the recalcitrant organic matter into readily biodegradable one (i.e., BDOC and AOC). We also investigated the differences of organic matter characteristics between BDOC and AOC. We observed the decreases in dissolved organic carbon (DOC) and the tryptophan-like fluorescence intensities. Liquid chromatographic - organic carbon detection (LC-OCD) analysis also showed the reduction of the low molecular weight (LMW) fraction (15% removed, less than 500 Da), which is known to be easily biodegradable, and the biopolymers, high molecular weight fractions (66%). Therefore, BDOC consists of a broad range of organic matter characteristics with respect to molecular weight. In AOC, low molecular weight organic matter and biopolymers fraction was reduced by 11 and 6%, respectively. It confirmed that biodegradation by microorganisms as the main removal mechanism in AOC, while BDOC has biodegradation by microorganism as well as the sorption effects from the sand. $O_3$ and $O_3+H_2O_2$ were compared with respect to biological stability and dissolved organic matter characteristics. BDOC and AOC were determined to be about 1.9 times for $O_3$ and about 1.4 times for $O_3+H_2O_2$. It was confirmed that $O_3$ enhanced the biodegradability by increasing LMW dissolved organic matter.

• 상하수도학회지
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• 제19권2호
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• pp.181-192
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• 2005

This study evaluated the effect of factors influencing the initial biofilm formation in drinking water distribution pipe by running experiments using a $2^{4-1}$ fractional factorial experimental design with a replicate. Important variables used for assessing biofilm formation included BDOC(biodegradable dissolved organic carbon), viable heterotrophic bacteria present in drinking water, water temperature, and shear stress at two levels each. Based on the statistical analysis of biofilm levels measured as attached HPC(heterotrophic plate count) and community-level assay, the main factors that have significant effects on biofilm formation were found to be viable heterotrophic bacteria and BDOC. Water temperature only exhibited significant effect on the levels of attached HPC, while shear stress was not a significant factor under given conditions. Moreover, the statistical analysis revealed that interactions between the important variables were not statistically significant at a 0.05 significance level.