• 한국습지학회지
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• 제13권3호
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• pp.697-705
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• 2011

본 연구의 목적은 다제 항생제 내성특성을 가진 pB10을 함유한 Escherichia coli DH 5 alpha,(E.coli $DH5{\alpha}$)를 대상 미생물로 하여 염소와 오존의 살균효율을 비교하는 것이다. 또한 다제 내성플라스미드 pB10에 대한 염소와 오존에 의한 제거율을 조사하였다. 주입농도 대비 오존살균이 염소살균에 비해 약 1.2~1.4 배 정도 효율이 높게 나타났다. 또한 다제 내성플라스미드 pB10에 대한 제거 실험에서 오존에 의한 제거율이 염소보다 약 2~4배 높게 나타났다. 오존살균에 의한 높은 pB10 제거효율은 오존 살균시 발생하는 OH 라디칼에 의한 것으로 사료된다. 이러한 연구결과로부터 내성균 및 유전물질을 효과적으로 제어하기 위하여 기존 염소살균법에 오존 또는 광촉매산화와 같은 고급산화법을 연계처리에 대한 필요가 있을 것으로 판단된다.

• 대한환경공학회지
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• 제28권11호
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• pp.1135-1140
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• 2006

국내 정수장에서 염소소독시 발생하는 소독부산물인 트리할로메탄(THMs), 할로아세틱에시드(HAAs)의 발생농도와 각각의 종별 분포현황을 조사하였다. 조사대상은 일반적인 정수처리공정으로 구성된 한강, 금강, 섬진강, 낙동강 수계의 1개 정수장씩 총 4개소였다. THMs의 발생농도는 평균 26.9 ppb, 최대 46.7 ppb, 최소 11.0 ppb였으며, $HAA_5$의 발생농도는 평균 25.4 ppb, 최대 57.1 ppb, 최소 9.7 ppb였다. 계절적으로는 동절기에 농도가 낮았고 하절기에 높았다. THMs의 종별 분포를 조사한 결과 클로로포름의 비율이 평균 77%로 가장 높았고 다음으로는 브로모디클로로메탄(20%)이 높게 검출되었으며, 브로모포름의 농도는 정량한계 미만이었다. $HAA_5$의 경우 디클로로아세틱에시드(DCAA)와 트리클로로아세틱에시드(TCAA)의 합이 $HAA_5$의 97%를 차지하는 것으로 조사되었다. 그러나 한강수계의 경우는 이 비율이 평균 90%로 다소 낮았으며, 특히 겨울철에 비율이 가장 낮았다. 한편, 하절기를 제외하고는 DCAA가 TCAA보다 높은 것으로 조사되었다.

• 한국물환경학회지
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• 제26권3호
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• pp.406-412
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• 2010

Concentrations and speciations of Trihalomethanes (THMs) and Haloacetic acids ($HAA_5$) that can be formed during chlorine disinfection by-product (DBPs) in full-scale drinking water treatment plants were investigated. Jeon-ju D water treatment plant that adopted conventional water treatment processes was chosen for investigation. SUVA values according to water treatment process changes were observed from 1.3 to 2.1. The process average concentrations of THMs was 7.4 ppb, 9.0 ppb and 14.7 ppb respectively, while the average concentrations of $HAA_5$ by each process which are precipitation water, filterater water, treated water, were 15.5 ppb, 14.9 ppb and 25.8 ppb respectively. DBPs concentrations was lower in the winter than summer. The major species of THMs was chloroform and the second highest was bromodichloromethane (BDCM) and the third highest was dibromochloromethane (DBCM). In case of $HAA_5$, the rate of trichloroacetic acid (TCAA) was detected. The species disribution of THMs is related to the change of SUVA and species disribution of $HAA_5$ is related to the concentrations of bromine and injection position of chlorine and injection quantity.

• Journal of Advanced Marine Engineering and Technology
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• 제38권8호
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• pp.1010-1020
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• 2014

Ballast water effluent treated by an electrolytic method contains reactive chlorine species and disinfection by-products (DBPs). In this study, we conducted whole effluent toxicity (WET) testing and ecological risk assessment (ERA) to investigate its ecotoxicological effects on marine environment. WET testing was carried out for three marine pelagic organisms, i.e., diatom Skeletonema costatum, rotifer Brachionus plicatilis and fish Paralichthys olivaceus. The biological toxicity test revealed that S. costatum was the only organism that showed apparent toxicity to the effluent; it showed no observed effect concentration (NOEC), lowest observable effect concentration (LOEC) and effect concentration of 50% (EC50) values of 12.5%, 25.0% and 83.3%, respectively, at brackish water condition. In contrast, it showed insignificant toxicity at seawater condition. B. plicatilis and P. olivaceus also showed no toxicities to the effluent at the both salinity conditions. Meanwhile, chemical analysis revealed that the ballast water effluent contained total residual oxidants (TROs) below $0.03{\mu}g/L$ and a total of 20 DBPs including bromate, volatile halogenated organic compounds (VOCs), halogenated acetonitriles (HANs), halogenated acetic acids (HAAs) and chloropicrin. Based on ERA, the 20 DBPs were not considered to have persistency, bioaccumulation and toxicity (PBT) properties. Except monobromoacetic acid, the ratio of predicted environmental concentration (PEC) to predicted no effect concentration (PNEC) of the other 19 DBPs did not exceed 1. Thus, our results of WET testing and ERA indicated that the ballast water effluent treated by electrolysis and subsequently neutralization was considered to have no adverse impacts on marine environment.

• 한국환경과학회지
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• 제1권1호
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• pp.53-68
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• 1992

In order to research the adsorption removal characteristics of trace organic by-products in disinfection of drinking water by biological activated carbon(BAC), water samples disinfect- ted with $Cl_2$, $O_3$ and $ClO_2$ after treatment by fluidized-bed system with water added with humic acid(10mg/L) were investigated the formation and the removal of trihalomethanes (THMs), and the trace organic by-products by gas chromatography(GC) II gas chromatography/mass selective detector(GC/MSD). Control was used by activated carbon(AC) and water added with humic acid(HA). The results were summarized as follow : The THMs removal effect of BAC by chlorination was in lower 90 % than that of control(HA), the sorts of oxidants formed by $Cl_2$ , $O_3$ and $ClO_2$ were that $O_3$ was very fewer than $Cl_2$ or $ClO_2$, and that $ClO_2$ was fewer than $Cl_2$. The trace organic by-products were esters and phthalates etc. Based on results above, it is concluded that BAC was appeared the more desirable adsorbtion-degradation removal characteristics than that of AC.

• Clinical and Experimental Pediatrics
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• 제46권2호
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• pp.198-202
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• 2003

국내 소아에서는 아직 화학 물질 흡입화상에 대한 보고가 없는 상태로 저자들은 수영장 창고에서 수영장 물의 살균, 소독제인 이염화이소시안산 나트륨과 차아염소산 칼슘을 잘못 혼합하던 중 발생한 소독제 분말 가스 폭발 반응에 노출되어 급격한 호흡 곤란증이 있었던 증례 2례를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제16권3호
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• pp.197-207
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• 2016

It is very important to maintain a constant chlorine concentration in the post chlorination process, which is the final step in the water treatment process (hereafter WTP) before servicing water to citizens. Even though a flow meter between the filtration basin and clear well must be installed for the post chlorination process, it is not easy to install owing to poor installation conditions. In such a case, a raw water flow meter has been used as an alternative and has led to dosage errors due to detention time. Therefore, the inlet flow to the clear well is estimated by a time series neural network for the plant without a measurement value, a new residual chlorine meter is installed in the inlet of the clear well to decrease the control period, and the proposed modeling and controller to analyze the chlorine concentration change in the well is a neuro fuzzy algorithm and cascade method. The proposed algorithm led to post chlorination and chlorination improvements of 1.75 times and 1.96 times respectively when it was applied to an operating WTP. As a result, a hygienically safer drinking water is supplied with preemptive response for the time delay and inherent characteristics of the disinfection process.

• 상하수도학회지
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• 제21권4호
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• pp.395-407
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• 2007

Disinfection by-products(DBPs) are formed through the reaction between chlorine and natural organic matter(NOM) in water treatment. For reducing the formation of chlorinated DBPs in the drinking water treatment, there is a need to evaluate the behavior of NOM fractions and the occurrence of DBPs for each fraction. Among the six fractions of NOM, the removal of HPOA and HPIN got accomplished through coagulation and sedimentation processes. Advanced water treatment processes were found to be most significant to remove the HPOA and HPON. It was found that HPOA made the most THMFP level than any other fractions and HPIA and HPOA formed higher HAAFP. The fraction of NOM with MW less than 1k Da was 32.5~54.3% in intake raw water. Mostly the organic matter with MW more than 1k Da was removed through coagulation and sedimentation in the drinking water treatment processes. In case of advanced water treatment processes, the organic matter with MW 1k~100k Da decreased by means of ozone oxidation for high molecular weight substances. As the result low molecular organic matter increased. In the BAC and GAC processes, the organic matter with MW less than 100k Da decreased.

• 대한치과보철학회지
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• 제27권2호
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• pp.249-259
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• 1989

Dental impression materials often become contaminated with patients' saliva and blood which creates the potential for cross-infection. It was the purpose of this study to investigate the effects of disinfection of three different rubber impression materials with four different disinfecting solutions. Polysulfide, vinyl polysiloxane and polyether impression materials were mixed according to the manufacturer's directions and samples were formed on a stainless steel model. On removal from the standard model, impressions were immersed in a disinfectant (acid-potentiated glutaraldehyde, phenollic compound, chlorine compound, iodophor) at room tempera tures for ten minutes. After disinfection, the distance between reference points(linear dimension) was measured using the non-contact automatic cordinate measuring projector(MZ-1, Nikon). Through statistical analyses on the data from this study,. the following conclusions were obtained. 1. Polysulfide, vinyl polysiloxane impressions were disinfected without dimensional change.(p>0.05) 2. Polyether impressions which were immersed in acid-potentiated glutaraldehyde were statistically different from control group.(p<0.05) But the amount of shrinkage(0.04%) would not be clinically significant. 3. By immersion of polysulfide, vinyl polysiloxane, polyether impressions in Banicide, Biocide, Multicide plus, sodium hypochlorite for ten minutes, clinically accurate impressions were obtained without dimensional change.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.263-272
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• 2005

Chlorine disinfection has been used in drinking water supply to disinfect the water-borne microbial disease which may cause to serious human disease. it is still the least costly, relatively easy to use, Chlorination is the primary means to disinfect portable water supplies and control bacterial growth in the distribution system. However, chlorine reacts with natural organic matter(NOM), that presents in nearly all water sources, and then produces disinfection by-products(DBPs), that have adverse health effects. Although the existent DBPs have been reported in drinking water supplies, it is not feasible to predict the levels of the various DBPs due to the complex chemistry reaction involved. 1. The objectives of this study is to investigate seasonal variation difference concentration of DBPs in the plant to tap water. The average concentration of THMs was 20.04 ${\mu}g/{\ell}$ , HAAs 8-15 ${\mu}g/{\ell}$ , HANs 2-4.5 ${\mu}g/{\ell}$ respectively. 2. Distant variation of DBPs furmation by the distance is that THMs concentration increased by 17% at 2km point from the plant and by 28% at 7km and HAAs, HANs also increase each by 16%, 32% at 2 km from the plant and 35%, 56% at 7 km. DBPs increase in water supply pipe continually, 3. The seasonal occurrence of BBPs is that in May and August DBPs concentration is very higher than in march, in May DBPs concentration is highest. The temperature is main factor of DBPs formation, precursor also. 4. Precursor which was accumulated for winter flowed into the raw water by flooding in spring and summer and produced DBPs. 5. Therefore for the supply of secure drinking water, it is required to protect precursor of flowing into raw water and to add to BCAA and DBAA to drinking water standards.