This study focuses on the application of a new measurement method that quantifies the residual color of filtered water using a spectrocolorimeter after filtering the discolored substances. It was confirmed through the color and turbidity cross-test that the discolored substances cannot be measured effectively with the current legal color and turbidity test method. Therefore, the National Institute of Environmental Research's filter testing method, which involves filtering the sample through 0.45 μm filter and visually inspecting the color, was improved. A membrane filter colorimetry (MFC) method was established by measuring the color difference (ΔE*ab(65)) of the filtered filter using a spectrophotometer and expressing it as filter color unit (FCU). Using the MFC method, the FCU for reference materials such as iron and manganese, as well as field samples, was measured. The results showed a high correlation with turbidity, and the color difference patterns varied depending on the type of reference materials and field samples. This indicates that the MFC method is an effective new measurement method of discolored tap water.

Scale and rust generation in water pipes is a common phenomenon when cast iron water pipes have been used for a long time. A physical water treatment device is known among various means for suppressing rust in a water pipe, and a zinc ionization device for putting zinc metal into a pipe and emitting the zinc cation into water is one of such devices. This research measured the amount of zinc ion generated, which is known to exhibit an effect of inhibiting rust and scale generation in a pipe, and examined the scale and rust inhibition effect of the ionization device installed for ground or building water supply. In the case of distilled water, the concentration of zinc ion increased by circulating water in the ionization device several times, and it was verified to be hundreds of μg/L, and in the case of discharging ground or tap water, it was verified to be tens of μg/L. In addition, a verification pipe was installed to confirm the change inside the pipe before and after installation of the zinc ionization device, and the internal condition of the pipe was observed 3 months to several years after installation. It was confirmed that the corrosion area of the surface of the pipe was no longer increased by installing a corrosion inhibitor, and if the pipe was already filled with corrosion products, the amount of corrosion products gradually decreased every year after installation. The phenomenon of fewer corrosion products could be interpreted as expanding the space in the pipe due to the corrosion product as Fe2O3 adhered to the inner surface of the pipe and turned into a smaller black Fe3O4. In addition, we found that scale such as CaCO3 together in the corrosion by-products gradually decreased with the attachment of the ionization device.

깔따구 (Diptera: Chironomidae)는 저서성 대형무척추동 물로 환경 및 수질 변화에 민감한 영향을 받는 중요한 환경 지표생물이다. 이러한 깔따구 유충이 정수장에서 본 연구에서는 제주 정수처리장에서 발견된 깔따구 유충의 종을 분류하기 위해 형태 사진 및 COI (cytochrome c oxidase subunit I) Primer로 증폭시킨 DNA의 염기서열을 계통수 분석을 통해 분석을 실시하였다. 정수장 내 수도꼭지와 소화관 등에서 채집된 17개체는 둥근깃깔따구 (O. tamarutilus) 14개체, 타마긴털깔따구 (P. tammaater) 3개체 총 2종으로 확인되었다. 각 깔따구 종의 형태적 특징은 두부, 하순기절, 대악, 안테나, 발톱의 형태적 특징의 분류기로 종 동정하였다. NCBI Genbank에 등록된 깔따구 19종 COI 염기서열을 기반으로 본 연구에서 조사된 17개체의 계통진화적 분석 결과 채집된 깔따구 COI 염기서열이 둥근깃깔따구 (O. tamarutilus)와 타 마긴털깔따구 (P. tammaater) 2종으로 각각 계통군 (clade)를 이루는 것이 확인되었다. 이러한 결과는 정수장 환경별 발견 되는 깔따구 유충의 다양성의 확인과 형태적-유전적 종 동정 분류정보를 바탕으로 수환경 관리 및 평가를 위한 기반 정보로 활용될 것이다.

깔따구 (Diptera: Chironomidae)는 저서성 대형무척추동 물로 환경오염 및 수질 모니터링에 이용되는 중요한 지표생물이다. 본 연구에서는 인천 수돗물 정수장에서 발견된 깔따구류의 정밀한 종 동정을 위해 형태적 분류와 미토콘드리아 DNA에서 cytochrome c oxidase subunit I (COI) 유전자의 염기서열을 이용하여 분석하였다. 정수장 6곳의 20 개체는 안개무늬날개깔따구 (Chironomus kiiensis) 12개체, 노랑털깔따구 (Chironomus flaviplumus) 6개체, 등깔따구 (Chironomus dorsalis) 1개체, 용산무늬깔따구 (Polypedilum yongsanensis) 1개체 등 4종으로 확인되었다. 각 깔따구 종의 형태적 특징은 두부, 하순기절, 대악, 안테나, 발톱의 형 태적 특징을 살펴보았다. NCBI Genbank에 등록된 깔따구 17종 21개체의 COI 염기서열을 바탕으로 본 연구에서 조사된 20개체의 계통진화적 분석한 결과 각 4종의 깔따구 COI 염기서열은 등록된 동인 종과 높은 상동성을 보이며 (99~100%) 같은 계통군 (clade)으로 나타났다. 이러한 결과는 국내 깔따구의 종 동정을 위한 형태적 - 유전적 정보를 통합적으로 제공함으로 담수생태계의 모니터링을 위한 주요한 정보로 활용될 것이다.

The point-of-use water dispenser systems are widely used because of convenience in handling and demand for high-quality drinking water. The application has been increased recently in the public places such as department stores, universities and the rest areas in express ways. Improvement of water qualities by the dispenser systems was compared with tap water in this study. The tap water is supplied to the dispenser as the influent of the dispenser system. The twelve dispensers in the public places were used. The five dispensers used reverse osmosis as the main filter and other dispensers used various filters such as ultrafiltration, nanofiltration, and alumina filter. The water quality indicators for sanitation safety, i.e., turbidity and total coliforms, were evaluated. Other water qualities such as pH, residual chlorine, heterotrophic plate count (HPC), and total cell counts were also analyzed. By the point-of-use water dispenser, the turbidity, residual chlorine and pH were decreased and the HPC and total cell counts were increased. The t-test results revealed that the HPC of the tap waters were not significantly different from the treated waters but the total cell counts of the two groups were significantly different. The low pH of the RO filter treatment was also significantly different from the tap waters. This study will contribute to understand the role of the point-of-use water dispenser in improving water quality and to identify key water quality for the proper maintenance of the dispenser systems.

One of the most effective methods to consistently ensure the safety of a tap water supply can be achieved by application of a comprehensive risk assessment and risk management approach for drinking water supply systems. This approach can be termed water safety plans(WSP) which recommended by WHO(world health organization) and IWA(international water association). For the introduction of WSP into Korea, 150 hazards were identified all steps in drinking water supply from catchment to consumer and risk assessment tool based on frequency and consequence of hazards were developed. Then, developed risk assessment tool by this research was implemented at a water treatment plant(Q=25,000 m3/d) to verify its applicability, and several amendments were recommended; classification of water source should be changed from groundwater to stream to strengthen water quality monitoring contaminants and frequencies; installation of aquarium to monitor intrusion of toxic substances into raw water; relocation or new installation on-line water quality analyzers for efficient water quality monitoring; change of chlorination chemical from solid phase(Ca(OCl)2) to liquid phase(NaOCl) to improve soundness of chlorination. It was also meaningful to propose hazards and risk assessment tool appropriate for Korea drinking water supply systems through this research which has been inconsistent among water treatment authorities. Key words: Hazard, Reliability, Risk management, Water safety plan, Tap water

Microorganisms detected in the biofilm not only cause secondary pollution of drinking water such as taste, odor and pathogenic disease but also increase the amount of disinfectant due to microbial regrowth during the transportation of tap water. In this work, the influence of C/N ratio in tap water on the characteristics of biofilm growth was examined. The C/N ratio of the tap water sample was controlled at 100:5, 100:10, 100:20, 100:30, and 100:40 by adding appropriate amounts of dextrose and (NH4)2SO4. Of the five C/N ratios, heterotrophic plate counts (HPC) was highest at the ratio of 100:10. Following the initial formation in all the five experimental conditions, natural detachment of the biofilm was observed. Extracellular enzyme activity (EEA) analyses showed that the change of the EEA during the experimental period was similar to that of the HPC, demonstrating a positive correlation between HPC and EEA. For TOC concentration in the tap water sample, approximately 75% of the TOC was consumed in 7 days of the experiment and 96% in 28 days. The TOC appeared to be relatively rapidly consumed at the initial phase of the biofilm growth. Consumption pattern of the ammonia nitrogen was different from the TOC consumption pattern showing the different role of ammonia nitrogen on the growth of biofilm.

We analyzed research trend and public perception related with tap water to identify major factors affecting low consumption of tap water. 805 research articles were collected for text mining analysis and 1,000 on-line questionnaires were surveyed to find social variables influencing tap water intake. Based on the word network analysis, research topics were divided into 4 major categories, 1) drinking water quality, 2) water fluoridation, 3) residual chlorine, and 4) micro-organism management. Compared with these major research topics, scientific studies of drinking behavior, or social perception were rather limited. 22.4% of total respondents used tap water as drinking water source, and only 1% drank tap water without further treatments (i.e. boiling, filtering). Experience of quality control report (B=0.392, p=0.046) and level of policy trust (B=1.002, p<0.0001) were influential factors on tap water drinking behavior. Age (B=0.020, p=0.002) and gender (B= - 1.843, p<0.0001) also showed significant difference. To increase the frequency of drinking the tap water by social members, the more scientific information of tap water quality and the water policy management should be clearly shared with social members.

Many advanced treatment processes have been introduced to WTPs, however, the consumer confidence on tap water is still low and the percentage of drinking water directly from the tap is less than 2 %. One of the methods to improve the credibility of tap water is to introduce a drinking water certification system. By introducing the system, water treatment processes can be optimized, which in turn, can significantly improve drinking water quality. In this paper, 6 water quality parameters(i.e., turbidity, CT, residual chlorine, geosmin, 2-MIB, Mn) which have significant influences on tap water quality and consumer confidence were identified, and their recommended guidelines were proposed. 3-Star or 5-Star certification can be awarded to the WTPs which have met the certification criteria. The drinking water certification system can be carried out as a voluntary program among drinking water suppliers.

하이그로마이신(hygromycin) 저항성 형질전환 동진 벼의 환경위해성 평가 기초자료를 위해 형질전환 벼와 일반 재배 동진 벼에 발생하는 곤충상을 2013년 7월부터 9월까지 조사하고 군집특성을 분석하였다. 형질전환 벼는 경상대학교 LMO(Living genetically Modified Organism) 격리포장 내에서 재배되었고, 일반 재배 동진 벼는 사천시 두량면과 진주시 대곡면에서 재배되었다. 조사기간 동안 LMO 격리포장에서는 총 7목 31과 65종 5,362개체가 채집되었고, 일반재배 벼를 재배하는 두량 1 포장은 총 5목 23과 44종 8,325개체, 두량 2 포장은 총 7목 16과 27종 4,027개체, 대곡 포장에서는 총 9목 30과 54종 4,785개체가 채집되었다. 총 조사된 곤충 종 수와 목 별 개체수의 비율은 딱정벌레목이 각각 29.3%와 88.6%로 가장 높았고, 애넓적물땡땡이(Enochrus simulans (Sharp))는 모든 포장에서 우점종이었다. 포충망을 이용한 쓸어잡기 방법으로 채집된 곤충은 29종으로 유아등 트랩으로 채집된 94종보다 낮았으나, 포장 별 구성종의 개체수 비율은 다양하였다. 전체 곤충 종 군집분석 결과 모든 포장에서 종 다양도가 낮고, 특정 종이 우점하는 등 농생태계 단일 경작지의 특성을 보였다. LMO 격리포장과 동진 벼 3개 포장간 유사도는 차이가 없는 것으로 나타났다. 본 실험결과 형질전환 벼와 비변형 벼에서 향후 환경위해성 평가를 위한 곤충상 조사는 유아등과 포충망 조사를 동시에 이용하는 것이 효과적인 것으로 확인되었다.

16 water treatment plants(WTPs) in Jeju province were investigated to evaluate the corrosivity of tap water. In addition, the impacts of lime and carbon dioxide on LI changes at ES WTP were analyzed. The average of LI in Jeju tap was -1.78 which was similar to that of in-land multi-regional WTPs. The recommended process to improve LI of ES WTP which has high corrosivity(i.e., LI = -2.61) was to combine lime and carbon dioxide with the dosages of 20 mg/L and 5 mg/L respectively to meet LI of -1.0 ~ 0. pH was confirmed to be a major water quality parameter that determined LI based on the correlation results among LI and water quality parameters. Precaution on turbidity increase by lime addition should given to minimize particle breakthrough in the distribution system. Turbidity increase can be controlled by the addition of lime prior to filters.

The paper is to estimate willingness-to-pay (WTP) for tap water quality improvement in Busan, using parametric approach in contingent valuation method(CVM). For parametric approach linear logit model and log logit model are employed in double-bounded dichotomous choice format of CVM. For the reliability and the validity of contingent valuation method a survey was conducted for 665 respondents, who were sampled by stratified random sampling method, by personal interview method. The result of mean WTP for the tap water quality improvement in Busan was estimated to be 3,687 won and 3,660 won per month per household, while median WTP being 1,884 won and 1,892 won per month per household, respectively by linear logit model and log logit model. Provided that our sample is broadly representative of the Busan’s population, an estimate of the annual aggregated benefit of residential water improvement for all Busan households is approximately 29.7 billion won to 29.8 billion won based on median WTP.

The tap water plays a critical role in our daily life by providing clean water for drinking as well as for residential use. Its importance, however, is often hidden and criticized in mass media because drinking the unprocessed tap water as a primary source of drinking water is very low comparing to other countries. This is because survey tool in Korea is often different from those in other countries so their results on the tap water cannot be directly compared without analysis on survey questionnaire. Therefore, we examplified cases showing the difference of questions of each country and discussed the reason why results of tap water intake should not be compared without analysis on the questions. Also, distrust on Arisu without rational reason is known as the first reason of distrust on the tap water. However, it was not the ultimate reason of distrust on the tap water. To verify, we designed survey questions in a tricky way that the same question was asked twice with different choices in the survey questionnaire. Most of the people who distrust Arisu without rational reason at the first question were selected different choices and significantly reduced in the second question. This proved that the ratio of distrust on the tap water is not actually the right reason and that by providing more choices, people’s distrust on the tap water without rational reason can turn into more specific reasons.

목적 : 인간작업모델에 근거한 맞춤형활동프로그램이 재택치매환자의 정신행동증상과 보호자의 부담에 미치는 효 과를 알아보고 치매환자의 정신행동증상 관리를 위한 기초자료를 제시하기 위함이다. 연구방법 : 2009년 6월부터 2009년 10월까지 경기도 Y시 치매예방관리센터에 내원한 지역사회에 거주하는 치매환 자 4명을 대상으로 하였다. 인간작업모델에 근거한 맞춤형활동프로그램은 전 후 평가를 포함하여 7주 동안 주 2회 (1회 가정방문, 1회 전화점검), 총14회를 실시하였다. 결과 : 맞춤형활동프로그램 실시 전에 비하여 실시 후에 재택치매환자의 정신행동증상의 심각도와 빈도의 점수는 감소되었으나 통계학적으로 유의한 차이가 없었다. 하지만 치매환자의 정신행동증상으로 인한 보호자의 부담과 반응은 통계학적으로 유의하게 감소하였다. 결론 : 인간작업모델에 근거한 맞춤형활동프로그램은 환자의 의지가 있는 목표활동을 통하여 역할 수행에 필요한 기술을 습관화하고 규칙적인 일과를 보낼 수 있도록 함으로써 지역사회에 거주하는 치매환자의 정신행동증상 감 소와 그로 인한 보호자 부담감을 감소시키는데 효과적으로 보인다. 작업치료는 치매환자의 개인적 요소, 과제, 환 경과 작업수행의 복잡한 관계를 고려하여 근거중심의 치료활동프로그램을 개발하고 실행할 수 있으므로 치매환자 를 위한 다양한 치료적 접근에 반드시 필요하다. 향후 지역사회에 거주하는 치매환자의 정신행동증상과 보호자 부 담감소를 위한 보다 다양한 치료적 접근에 대한 연구가 필요하다.

Saline-tab water (2.5 L) with 0, 2.5, 5, and 10% saline solution contaminated by P. aeroginosa or S. aureus, was electrolyzed with constant electrical current of 2A or 4A for different time durations (1, 2, 4, 8, and 16min). The electrolysis with 2A-4min showed disinfection effect against P. aeroginosa of 105 CFU/㎖ in all saline concentrations. When the electrical current was raised to 4A, P. aeroginosa of 106 CFU/㎖ was disinfected in 4 min. S. aureus of 105 CFU/㎖ was disinfected with 2A-2 min in all saline concentrations. S. aureus of 106 CFU/㎖ was completely disinfected with 2A-8 min. To compare the effect of constant current electrolysis with that of intermittent current electrolysis, solution contaminated with P. aeroginosa of 106 CFU/㎖ was electrolyzed with several pairs of intermittent current of 2A for 2 min followed by 2min pause. Disinfecting effect of intermittent electrolysis was very similar to the constant current electrolysis without pause in 16 min. The present study demonstrated that the direct electrolyzing process with no septum membrane is a convenient and economic sterilization method.

기존의 정수처리 공정인 응집 침전 과정을 대체하여 분리막을 이용한 상수처리 시스템의 개발을 목적으로한다. 따라서 4가지 형태의 정수처리 공정과 분리막의 분획 분자량을 변화시켰을 때 막 투과수의 변화와 안정적이며 높은 투과수를 얻기 위해 필요한 운전 조건의 최적화를 실험하였다 실험결과 한외여과막이 정밀여과막보다 막 투과수 감소경향이 완만했으며 초기 투과수 회복율은 더 높았다. 수질 분석의 결과 한회여과막이 정밀 여과막보다 우수하였지만 전처리에 의한 차이는 나지 않았다. 운전 조건에 따른 flux 는 온도, 선속도가 높을수록 압력이 낮을수록 flux 감소율이 적은 경향을 나타내었다.