활성슬러지 미생물의 탈질 활성에 대한 염소의 저해

최진택,남세용,Choi, Jin-Taek,Nam, Se-Yong 한국환경보건학회 2007 한국환경보건학회지 Vol.33 No.4

Chlorine inhibition on the denitrifing activity of activated sludge treating dairy wastewater was investigated in this study. Filamentous bulking was caused artificially by a sudden load of feed and monitored by measuring sludge volume index. In cases of the activated sludge and bulking sludge which were contacted with chlorine as $7.5\;mgCl_2/gVSS/day$ for bulking control, the decreases of specific denitrification of $32.2{\sim}40.4%\;and\;43.5{\sim}46.5%$ were shown in comparison to the control group which was not reacted with chlorine, respectively. In continuous operation, it was observed that the removal efficiency of total nitrogen was more susceptible to chlorine than the removal efficiency of total phosphorus.

유가공 폐수의 활성슬러지 처리에서 벌킹 제어용 염소가 미생물의 유기물 분해 활성에 미치는 영향

남세용,최진택,Nam Se-Yong,Choi Jin-Taek 한국환경보건학회 2006 한국환경보건학회지 Vol.32 No.1

Chlorination inhibition on the organic removal activity of activated sludge microorganism was investigated in this study. It is well known that chlorination improves the settleability of filamentous bulking sludge through the selective impediment of filamentous microorganisms. However, it is based on the declination of effluent water quality after actual chlorination in dairy wastewater treatment plant. In case of the activated sludge which was exposed in the suggested concentration of chlorine $7.5\;mgCl_2/gVSS/day$ for the filamentous bulking control, decrease of organic uptake rate of $4.9\~24.0\%$, and dentrification rate of $24.8\~30.3\%$ ware shown in comparison to the control group which was not reacted with chlorine. As a result of comparing floc size of activated sludge microorganism, the average of floc diameter in the chlorine exposed group was $150\;{\mu}m$, which displays $25\%$ decrease compared with the control group.

수돗물 수질분석결과 신뢰도 개선 방안 연구

김영진 ( Young Jin Kim ),배석문 ( Seog Moon Bae ),송미정 ( Mi Jeong Song ),이희숙 ( Hee Suk Lee ),고재현 ( Jae Hyun Ko ),정화숙 ( Hwa Suk Jeong ),문신득 ( Sin Deuk Moon ),최진택 ( Jin Taek Choi ),노재순 ( Jae Soon Roh ),빈재훈 ( J 한국수처리학회 2011 한국수처리학회지 Vol.19 No.4

Our institute has been carried out to secure a confidence for the analysis results. As a result, we obtained a certificate of accreditation for International Laboratory Accreditation Scheme in analytical criteria of 55 parameters of drinking water quality. The Korea Laboratory Accreditation Scheme (KOLAS) also accredited our testing laboratories in accordance with the provisions of Acticle 2.021 of the National Standards. For a reliability for analytical results of water quality, a measurement uncertainty of 74 % mainly depended on the calibration curve of standard solution. Based on the mid-test results of quality assurance (QA)/ quality control (QC) for laboratory facilities, the limit of quantification for volatile organic compounds (VOC) was in the range of 2~3 ㎍/L, which was in the range of a goal value of the quality control. The R2 value of calibration curve for the VOC was 0.99. The precision and accuracy also were in the range of 1~2 % and 94~115 %, respectively. For proficiency test, we obtained an accreditation of an objective analytical ability by getting a suitable decision through a participation (total 14th times) in proficiency test, which had been held on a domestic and foreign.

DGGE 기법을 이용한 생물활성탄 공정의 부착 박테리아 군집분석

손희종(Hee Jong Son),최진택(Jin Taek Choi),손형식(Hyeng Sik Son),이상준(Sang Joon Lee) 大韓環境工學會 2012 대한환경공학회지 Vol.34 No.8

BAC 공정 운전초기부터 부착 박테리아들의 생체량이 정상상태(steady-state)에 도달한 이후까지 BDOCtotal/rapid/slow 제거율의 변화와 DGGE와 ATP 분석을 통하여 부착 박테리아들의 군집과 생체량을 평가하였다. 용존 유기물질 제거율 평가에 따른 BAC 공정의 정상상태 도달 여부 평가결과를 보면 DOC의 경우 운전 bed volume 27,500 부근에서 BAC 공정이 정상상태에 도달하였고, BDOCrapid와 BDOCtotal/slow의 경우는 각각 운전 bed volume 15,000 부근과 32,000 부근에서 정상상태에 도달하였다. BAC 공정의 운전기간 증가에 따른 HPC 및 ATP 농도 분석을 통한 부착 박테리아들의 생체량 평가결과 bed volume 22,500 이후로 거의 일정한 생체량을 유지하였으며, 이때 HPC와 ATP 농도는 각각 3.3×108cells/g 및 2.14μg/g 정도로 나타났다. DGGE를 이용하여 운전기간 증가에 따른 BAC 부착 박테리아들의 군집분석 결과 운전초기(bed volume 8,916)의 경우 분석가능한 DGGE band 개수가 5개였으나 운전기간 증가에 따라 분석가능한 DGGE band 개수는 최대 11개로 증가하였다. 또한, DGGE를 이용한 박테리아 군집분석 결과 BAC 운전기간의 증가에 따라 다양한 박테리아 그룹들이 존재하였고, Pseudomonas fluorescens, Acinetobacteria와 유사한 uncultured bacterium, uncultured Novosphingobium sp. 및 Flavobacterium frigidarium은 운전초기 단계부터 지속적으로 부착 박테리아 군집을 형성하였고, 전체적으로 Proteobacteria 그룹이 비교적 높은 비율로 우점하였다. The concentration of organic compounds was analyzed at each step of BAC (biological activated carbon) process though BDOC (biodegradable dissolved organic carbon) total/rapid/slow. Further, bacteria communities and biomass concentrations measured DGGE (denaturing gradirnt gel electrophoresis) and ATP (adenosine triphosphate) methods were analyzed. The bed volume of steady state is different based on assessment of organic compounds removal. Bed volumes at steady state in DOC, BDOCrapid and BDOCtotal/slow removal were around 27,500, 15,000 and 32,000, respectively. A biomass didn`t change after the bed volume reached 22,500 according to analyzing HPC (heterotrophic plate count) and ATP concentration of bacteria. The concentration of HPC and ATP were 3.3×108cells/g and 2.14μg/g, respectively. The number of the DGGE band were only 5 at the bed volume 8,916, but increased up to 11 at the bed volume 49,632. As operation time increase, bacterial group were more diversity. Four bacteria species including Pseudomonas fluorescens, the uncultured bacterium similar to Acinetobacteria, uncultured Novosphingobium sp. and Flavobacterium frigidarium have detected from the early stages and Proteobacteria group were dominantly detected.

음식물류폐기물 및 배출폐수의 특성

김영권,김세미,김민규,최진택,남세용,Kim, Young-Kwon,Kim, Se-Mi,Kim, Min-Kyu,Choi, Jin-Taek,Nam, Se-Yong 한국환경보건학회 2009 한국환경보건학회지 Vol.35 No.6

Waste generation was generally expected to steadily rise due to a rapid increase in population and economic growth. However, regulations on disposable goods and a volume-based waste fee system have led to a gradual reduction in the amount of waste. In the case of food waste, separation of food waste from other waste has been put in place since direct landfilling was banned in January 2005. The predicted generation amounts of food waste and wastewater in the model city were 54 ton/d and 127.3 ton/d by year 2020, respectively. However, appropriate treatment technologies for food waste and wastewater discharged from food waste treatment processes are yet to be established. In this study, the food waste and wastewater discharged from food waste treatment process in the model city were characterized by literal and field investigation.

낙동강 원수를 대상으로 Al염계 및 Fe염계 응집제를 이용한 고도응집의 적용

문신득(Sin Deok Moon),손희종(Hee Jong Son),염훈식(Hoon Sik Yeom),최진택(Jin Taek Choi),정철우(Chul Woo Jung) 大韓環境工學會 2012 대한환경공학회지 Vol.34 No.9

고도응집 공정은 DBP 전구물질인 NOM을 제거하는 최적기법이다. 본 연구에서는 낙동강 원수를 대상으로 FeCl₃, alum, PSOM 및 PACl 응집제를 대상으로 고도응집 공정의 적용시 가장 효과적인 응집제와 응집조건을 DOC, THMFP, HAAFP 및 제타전위 변화를 중심으로 평가하였다. 탁도 제거율은 고도응집을 적용시 기존응집에 비해 제거율의 상승은 없었으며, 일정 응집제 주입량 이상에서는 제거율이 더욱 저하되었으나 DOC, THMFP 및 HAAFP 제거율은 응집제 종류별로 기존응집에 비해 각각 13~18%, 9~18% 및 9~18% 정도 증가하였다. 응집 pH 변화에 따른 탁도 제거특성은 FeCl₃와 PACl이 pH 4~10 범위에서 비교적 높은 탁도 제거율을 나타내었고 alum과 PSOM의 경우는 pH 5~8의 범위에서 안정적인 제거율을 나타내었다. DOC는 4종의 응집제 모두 pH 5~7 범위에서 안정적인 제거율을 나타내었다. 고도응집 공정을 적용시 1 kDa 이하 및 10 kDa 이상의 용존 유기물질의 제거율은 각각 11~21% 및 16% 정도 기존응집 공정에 비해 증가하였으며, 소수성 및 친수성 유기물질의 제거율은 각각 27~38% 및 11~15% 정도 증가하였다. 낙동강 원수의 고도응집에 가장 효과적인 응집제로는 FeCl₃로 나타났으며, 다음으로 PSOM, PACl 및 alum 순이었다. Enhanced coagulation is best available technologies to treat NOM in water to produce clean drinking water. In this research, the comparison experiments between conventional coagulation (CC) and enhanced coagulation (EC) using 4 type coagulants i.e., ferric chloride, aluminium sulphate (alum), poly aluminium sulphate organic magnesium (PSOM) and poly aluminium chloride (PACl) were performed in terms of surrogate parameters such as dissolved organic carbon (DOC), trihalomethane formation potential (THMFP), haloacetic acid formation potential (HAAFP) and zeta potential variation in order to find out the most effective coagulant and conditions to fit Nakdong River water. When applied to EC process, the turbidity removal efficiency did not increased gradually compared to the CC process when adding coagulants. Furthermore, the removal efficiency of turbidity became decreased much more as coagulants were added increasingly whereas the removal efficiency of DOC, THMFP and HAAFP became increased by 13~18%, 9~18% and 9~18% respectively compared to the CC process. The characteristics of turbidity removal showed relatively high removal efficiency considering the pH variation in entire pH range when using FeCl₃ and PACl. Additionally, in case of alum and PSOM steady removal efficiency was shown between pH 5 and pH 8. In terms of DOC surrogate the coagulants including 4 type coagulants indicated high removal efficiency between pH 5 and pH 7. The removal efficiency of dissolved organic matter (DOM) in EC between less than 1 kDa and more than 10 kDa augmented by 11~21% and 16% respectively compared to the CC process. The removal efficiency of hydrophobic and hydrophilic organic matter proved to be increased by 27~38% and 11~15% respectively. In conclusion, the most effective coagulant relating to EC for Nakdong River water was proved to be FeCl₃ followed by PSOM, PAC and alum in order.

Microcystis sp. Cell의 부패와 염소 소독부산물 생성

손희종(Hee Jong Son),염훈식(Hoon Sik Yeon),정종문(Jong Mun Jung),최진택(Jin Taek Choi) 大韓環境工學會 2012 대한환경공학회지 Vol.34 No.5

Microcystis sp.의 부패과정에서 수중으로 용출되는 AOM 특성과 염소 이들에서의 disinfection by-products (DBPs) 생성 특성을 조사하였다. 수중으로 용출된 EOM과 cell + IOM에서의 염소 DBPs 생성특성을 조사한 결과, EOM은 보관기간 초기부터 지속적으로 증가하였으나 cell + IOM의 경우는 급격한 감소경향을 나타내었으며, 생성된 DBPs 중 HAAFP가 가장 높은 생성 비율을 나타내었다. 또한, 이 때의 DBP 구성종들의 변화를 살펴본 결과, HAA 구성종들의 경우는 EOM에서는 di-HAA 구성종들의 비율은 점점 감소하였고 tri-HAA 구성종들의 비율은 점점 증가하였다. 그러나 cell + IOM의 경우는 EOM의 경우와는 반대 경향을 나타내었다. 또한, HAN 구성종들의 경우는 EOM과 cell + IOM 모두 di-HAN 구성종들의 생성비율이 월등히 높았다. Formation of disinfection by-products (DBPs) including trihalomethans (THM), haloacetic acid (HAA) and haloacetonitriles (HAN) from chlorination of extracellular organic matter (EOM) and cells + intracellular organic matter (IOM) of Microcystis sp., a blue-green algae, during decomposed period was investigated. Microcystis sp. cells + IOM and EOM of Microcystis sp. exhibited a high potential for DBP formation. HAAFP (formation potential) was higher than THMFP during decomposed period. In the variations of HAAFP species during decomposed period, the ratio of di-HAAFP species was gradually decreased and the ratio of tri-HAAFP species was gradually increased in the case of EOM during decomposed period, while the opposite result was in the case of cells + IOM during decomposed period. In the variations of HANFP species during decomposed period, the ratio of di-HANFP species was much higher than the ratio of tri-HAAFP species.

교반막대 추출법과 GC/MS-MS를 이용한 수중의 자외선 차단제 분석

서창동 ( Chang Dong Seo ),서창동 ( Hee Jong Son ),정종문 ( Jong Moon Jung ),최진택 ( Jin Taek Choi ),장성호 ( Seong Ho Jang ) 한국환경과학회 2014 한국환경과학회지 Vol.23 No.6

A highly sensitive analytical method based on stir bar sorptive extraction (SBSE) technique and gas chromatography/tandem mass spectrometry (GC/MS-MS) has been developed, allowing the simultaneous multi-analyte determination of seven UV filters in water samples. The stir bar coated with polydimethylsiloxane (PDMS) was added to 40 mL of water sample at pH 3 and stirred at 1,100 rpm for 120 min. Other SBSE parameters (salt effect and presence of organic solvent) were optimised. The method shows good linearity (coefficients > 0.990) and reproducibility (RSD < 12.9%). The extraction efficiencies were above 84% for all the compounds. The limits of detections (LOD) and limits of quantification (LOQ) were 2.1∼8.6 ng/L and 6.8∼27.5 ng/L, respectively. The developed method offers the ability to detect 8 UV filters at ultra-low concentration levels with only 40 mL of sample volume. Matrix effects in tap water, river water, wastewater treatment plant (WWTP) final effluent water and seawater were investigated and it was shown that the method is suitable for the analysis of trace level of 7 UV filters except of benzophenone (BP). The method developed in the present study has the advantage of being rapid, simple, high-sensitive and both user and environmentally friendly.

교반막대 추출법과 GC-MS/MS를 이용한 수중의 합성 향물질류 분석

서창동(Chang Dong Seo),손희종(Hee Jong Son),염훈식(Hoon Sik Yoom),최진택(Jin Taek Choi),류동춘(Dong Choon Ryu),권기원(Ki Won Kwon),장성호(Seung Ho Jang) 大韓環境工學會 2014 대한환경공학회지 Vol.36 No.6

본 연구에서는 SBSE 전처리 장치와 GC-MS/MS를 이용하여 합성 향물질 11종을 동시 분석할 수 있는 분석법을 개발하기 위해 흡착 bar의 교반시간, 교반속도, 시료수의 pH, 시료수 용량, 염석제 투입량 및 메탄올 주입량 변화 등 SBSE (stir barsorptive extraction) 전처리 조건과 GC-MS/MS (gas chromatography/tandem mass spectrometry)의 기기조건을 다양하게 변화시켜 SBSE-GC-MS/MS를 이용한 분석법을 개발하였다. 11종의 합성 향물질들에 대한 검출한계(LOD)는 2.1~4.1 ng/L였으며, 정량한계(LOQ)는 6.6~12.9 ng/L였다. 수돗물, 낙동강 원수, 하수처리장 최종방류수 및 해수를 이용하여 시료수의 matrix 영향을살펴본 결과, 11종의 합성 향물질들의 회수율 및 RSD의 경우 각각 88%~119% 및 0.8%~7.5%로 양호한 결과를 나타내어 시료수의 matrix 영향을 받지 않는 것으로 나타났다. 본 연구에서 개발된 SBSE-GC-MS/MS 분석법은 40 mL 정도의 적은 시료수량으로도 고감도 분석이 가능하며, 용매류를 사용하지 않기 때문에 분석자의 건강 및 환경친화적인 분석법이라는 장점뿐만 아니라 간편하고, 빠르며 자동화된 방법이라는 장점을 가진다. A highly sensitive analytical method based on stir bar sorptive extraction (SBSE) technique and gas chromatography/tandem mass spectrometry (GC-MS/MS) has been developed, allowing the simultaneous multi-analyte determination of 11 syntheticfragrances (SFs) in water samples. The stir bar coated with polydimethylsiloxane (PDMS) was added to 40 mL of water sample atpH 3 and stirred at 1,100 rpm for 120 min. Other SBSE parameters (salt effect and presence of organic solvent) were optimised. The method shows good linearity (coefficients > 0.990) and reproducibility (RSD < 10.9%). The extraction efficiencies were above83% for all the compounds. The limits of detections (LOD) and limits of quantification (LOQ) were 2.1~4.1 ng/L and 6.6~12.9ng/L, respectively. The developed method offers the ability to detect 11 SFs at ultra-low concentration levels with only 40 mL ofsample volume. Matrix effects in tap water, river water, wastewater treatment plant (WWTP) final effluent water and seawaterwere investigated and it was shown that the method is suitable for the analysis of trace level of 11 SFs. The method developedin the present study has the advantage of being rapid, simple, high-sensitive and both user and environmentally friendly.

남조류의 염소처리에 따른 미량의 염소 소독부산물 생성에 관한 연구

손희종 ( Hee Jong Son ),정종문 ( Jong Moon Jung ),염훈식 ( Hoon Sik Yeom ),최진택 ( Jin Taek Choi ),장성호 ( Seong Ho Jang ) 한국환경과학회 2012 한국환경과학회지 Vol.21 No.8

Formation of disinfection by-products (DBPs) including trihalomethans (THMs), haloacetic acid (HAAs), haloacetonitriles (HANs) and others from chlorination of algogenic organic matter (AOM) of Microcystis sp., a blue-green algae. AOM of Microcystis sp. exhibited a high potential for DBPs formation. HAAs formation potential was higher than THMs and HANs formation potential. The percentages of dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) formation potential were 43.4% and 51.4% in the total HAAs formation potential. In the case of HANs formation potential, percentage of dichloroacetonitrile (DCAN) formation potential was 97.7%. Other DBPs were aldehydes and nitriles such as acetaldehyde, methylene chloride, isobutyronitrile, cyclobutanecarbonitrile, pentanenitrile, benzaldehyde, propanal, 2-methyl, benzyl chloride, (2-chloroethyl)-benzene, benzyl nitrile, 2-probenenitrile and hexanal.