The emergence of micropollutants in natural water sources due to the overuse of anthropogenic chemicals in industry and households has threatened the production of clean and safe tap water in drinking water treatment plants. Conventional physicochemical processes such as coagulation/flocculation followed by sand filtration are not effective for the control of micropollutants, whereas chemical oxidation processes (applying chlorine, permanganate, ozone, etc.) are known to be promising alternatives. Determining the optimum oxidant dose is important issue related to the production of disinfection by-products as well as unnecessary operating cost, and is made possible by simulations of target-micropollutant abatement based on kinetic model equation consisting of second-order rate constant (between the oxidant and the target) and oxidant exposure. However, the difficulty in determining oxidant exposure as a function of complex water quality parameters limits the field application of kinetic model equation. With respect to representative oxidants used in drinking water treatment plants, this article reviews two main approaches for determining oxidant exposure: i) direct measurement in situ and ii) prediction by empirical models based on key water quality parameters. In addition, we discussed research requirements to improve the predictive accuracy of the empirical models for oxidant exposure and to develop a rational algorithm to determine optimal oxidant dose by considering the priority of the target pollutants to be treated.

The frequent detection and occurrence of micropollutants (MPs) in aquatic ecosystems has raised public health concerns worldwide. In this study, the behavior of 50 MPs was investigated in three different domestic wastewater treatment plants (WWTPs). Furthermore, the Kruskal-Wallis test was used to assess the geographical and seasonal variation of MPs in the WWTPs. The results showed that the concentrations of 43 MPs ranged from less than 0.1 to 237.6 μg L-1, while other seven MPs including 17-ethynylestradiol, 17-estradiol, sulfathiazole, sulfamethazine, clofibric acid, simvastatin, and lovastatin were not detected in all WWTPs. Among the detected MPs, the pharmaceuticals such as metformin, acetaminophen, naproxen, and caffeine were prominent with maximum concentrations of 133.4, 237.6, 71.5, and 107.7 μg L-1, respectively. Most perfluorinated compounds and nitrosamines were found at trace levels of 1.2 to 55.3 ng L-1, while the concentration of corrosion inhibitors, preservatives (parabens), and endocrine disruptors ranged from less than 0.1 to 4310.8 ng L-1. Regardless of the type of biological treatment process such as MLE, A2O, and MBR, the majority of pharmaceuticals (except lincomycin, diclofenac, iopromide, and carbamazepine), parabens (except Methyl paraben), and endocrine disruptors were removed by more than 80%. However, the removal efficiencies of certain MPs such as atrazine, DEET, perfluorinated compounds (except PFHxA), nitrosamines, and corrosion inhibitors were relatively low or their concentration even increased after treatment. The results of statistical analysis reveal that there is no significant geographical difference in the removal efficacy of MPs, but there are temporal seasonal variations in all WWTPs.

Conventional wastewater treatment plants (WWTPs) do not fully remove micropollutants. Enhanced treatment of sewage effluents is being considered or implemented in some countries to minimize the discharge of problematic micropollutants from WWTPs. Representative enhanced sewage treatment technologies for micropollutant removal were reviewed, including their current status of research and development. Advanced oxidation processes (AOPs) such as ozonation and UV/H2O2 and adsorption processes using powdered (PAC) and granular activated carbon (GAC) were mainly discussed with focusing on process principles for the micropollutant removal, effect of process operation and water matrix factors, and technical and economic feasibility. Pilot- and full-scale studies have shown that ozonation, PAC, and GAC can achieve significant elimination of various micropollutants at economically feasible costs(0.16-0.29 €/m3). Considering the current status of domestic WWTPs, ozonation and PAC were found to be the most feasible options for the enhanced sewage effluent treatment. Although ozonation and PAC are all mature technologies, a range of technical aspects should be considered for their successful application, such as energy consumption, CO2 emission, byproduct or waste generation, and ease of system construction/operation/maintenance. More feasibility studies considering domestic wastewater characteristics and WWTP conditions are required to apply ozonation or PAC/GAC adsorption process to enhance sewage effluent treatment in Korea.

Due to the large-scale production and use of synthetic chemicals in industralized countries, various chemicals are found in the aquatic environment, which are often termed as micropollutants. Effluents of municipal wastewater treatment plants (WWTPs) have been identified as one of the major sources of these micropollutants. In this article, the current status of occurrence and removal of micropollutants in WWTPs and their management policies and options in domestic and foregin countries were critically reviewed. A large number of pharmaceuticals, personal care products, and industrial chemicals are found in WWTPs’ influent, and are only partially removed by current biological wastewater treatment processes. As a result, some micropollutants are present in WWTPs’ effluents, which can negatively affect receiving water quality or drinking water source. To better understand and assess the potential risk of micropollutants, a systematic monitoring framework including advanced analytical tools such as high resolution mass spectrometry and bioanalytical methods is needed. Some Western European countries are taking proactive approach to controlling the micropollutants by upgrading WWTP with enahnced effluent treatment processes. While this enahnced WWTP effluent treatment appears to be a viable option for controlling micropollutant, its implementation requires careful consideration of the technical, economical, political, and cultural issues of all stakeholders.

미량화학물질은 미량 (ng/L)으로 인체 또는 환경에 심각한 피해를 줄 수 있는 물질이므로, 효과적인 미량오염물질 제거 시스템 개발이 필요한 실정이다. 분리막 기반 수처리 공정 중 정삼투 공정은 미량화학물질을 효과적으로 제어할 수 있는 저에너지, 친환경 공정으로 각광받고 있으나, 제거율, 제거기작, 공정최적화 등의 연구가 필요한 실정이다. 따라서, 본 연구에서는 정삼투 공정을 이용하여 미량화학물질의 제거성능을 평가하고 그 기작을 평가하여 수계 내 존재하는 미량오염물질을 신속하고 효율적으로 처리할 수 있는 삼투막 기반 막공정 공법을 제시하고자 한다.

최근 대두된 난분해성 미량오염물질은 일반적인 수처리 공법으로는 제거가 잘 되지 않고 수 ng/L 단위로도 수중생태계와 인간에게 독성을 나타내므로 반드시 처리가 필요하다. 따라서 본 연구에서는 CNT (Carbon nanotube)를 이용하여 중공사막을 제조한 후, 그것을 전극으로 사용하여 미량오염물질을 전기화학적으로 산화 제거하였다. SEM, BET, flux, conductivity 결과를 통해 전극의 특성을 분석하였다. BPA(bisphenol A), Sulfamethoxazole(SMX), N,N-Diethyl-metatoluamide(DEET) 3가지 물질을 제거 대상 미량오염물질로 선정하였고 CHM 산화극 내부로 오염물질이 포함된 물을 흘려 보내주었을 때 5분 만에 100%의 제거효율을 보였다.

물은 신체의 대부분을 구성하고 있는 기본 물질로서 생명유지의 필수 요소이다. 특히 WHO에서는 인류 건강유지의 1등 공신으로 깨끗한 물공급을 꼽고 있다. 우리나라는 산업화, 도심화를 통해 신규오염물질 발생이 증가하고 있으며 특히 먹는물의 경우 중금속 및 소독부산물 중심의 관리에서 난연제, 코팅제, 의 약물질 등 신규오염물질 관리에 주력하고 있다. 우리나라 먹는물 수질기준은 1963년 최초 도입된 이래 1984년, 1986년 개정 강화되었으며, 1995년 먹는물 관리법이 제정되었고 1997년 감시항목이 설정되 어 기준과 감시의 2원화된 관리체계가 유지되고 있다. 먹는물 수질기준은 외국 사례 도입방식에서 체계적 장기 모니터링을 통한 위해도 평가를 수행하여 기준을 강화하고 있으며 현재 60개 항목으로 확대 강화되었다.

This study examined the occurrence and removals of 14 micropollutants in the influents and the treated effluent of each process in a WTP. 12 out of the 14 micropollutants were detected in the influent source waters and 11 compounds survived in the final effluent at ppt level. MPT showed the highest level in both the influent and effluent. There was a seasonal variation in the micropollutant level. Most of the removals of micropollutants occurred at the coagulation stage in the WTP. Our results indicate that the removal of micropollutants during lab scale experiment and at the WTP can be somewhat different, and the physicochemical properties are important parameters in the removal of micropollutants during the WTP.

도시 하수는 미량오염물질의 수환경 배출 주요 점오염원이며 인구증가 및 도시화로 향후 도시인근 수자원 수질에 미치는 영향이 증가할 것으로 예상된다. 규제측면에서는 그 위해성이 명확하고 대표성이 있으며 현실적 제거 목표 달성이 가능한 오염물질에 대하여 수질기준정립이 예상된다. 하수 유출수에서 미량오염물질 제거를 위한 산화 (오존, UV/H2O2), 흡착 (분말활성탄), 막분리 (NF, RO)) 세가지 공정에 대한 연구가 활발한데, 본 발표에서는 위와 같이 도시 수환경 미량오염물질 이슈와 초고도 하수 처리공정에 대해 살펴보겠다.

우리 나라의 먹는물 검사항목에 지정되지 않은 32가지 오염물질의 원수에 대한 분포에 대하여 1997년과 1998년사이에 조사되었다. 조사대상 물질은 16가지 휘발성 유기물질과 7가지 유기인계 농약 그리고 8가지의 중금속과 우라늄 등이었다. Chlorobenzene, 1, 4-Dichloro- benzene, 1, 3-Dichloropropane이 휘발성 유기물질 중에서 0.03~1.33 μg/l 범위에서 검출되었다. Sr과 Ba, B은 다른 중금속들에 비해 상대적으로 높은 농도로 나타 났고, 검출 평균농도는 Sr이 25~60 μg/l, B는 약 5~40 μg/l 농도범위로 나타났다. Tl, Ni, Be, Mo, Sb과 U은 미 량 혹은 검출한계 이하의 값으로 조사되었다. Lindane 을 포함한 일곱가지 유기염소계 농약의 경우 1998년 한 해 동안 25개 조사대상지점에서 모두 검출한계 이하의 값으로 조사되었다. Chlorobenzene, 1, 4-Dichlorobenzene, Ba, B에 대한 WHO의 권고기준치는 모두 300 μg/l으로서 이번에 검출된 물질의 농도는 모두 이 기준치 이하로 나타 났다. 이 결과는 이들 조사 대상 항목으로 인한 원수의 오염 가능성이 매우 낮음을 보여준다.

Micropollutants, which can be caused by imperfect combustion, are toxic chemical compound that flows into the river system after being contained in road runoff, a non-point source pollutant and accumulates in the body. The micropollutants that have characteristics such as toxicity, persistence, bio-accumulation, long-range transportation behave so similarly to micro particles that they can be removed by means of filtration or absorption. This study has examined the kinds and concentrations of micropollutants contained in deposited road particles. It has revealed that the kinds of micropollutants contained in the clarified supernatant liquid of deposited road particles are heavy metals and polycyclic aromatic hydrocarbons(PAHs) composed of two or three benzene rings, including naphthalene and acenaphthalene. Their concentrations have been shown to be low, with 0.418 mg/L, 0.058 mg/L, 0.104 mg/L, 0.014 mg/L, 0.00075 mg/L for Zn, Pb, Cu, Cr, Cd, respectively and 0.00156 mg/L and 0.00184 mg/L for naphthalene and acenaphthalene.

This study investigated the distributive property of micropollutants in sediment around Gwang-yang bay using simultaneous analytical method of 310 chemicals. In the results, the major micropollutants detected were CH type chemicals such as aliphatic, polycyclic compounds, benzenes, and CHN(O) type chemicals aromatic amines, and pesticides. Insecticides of pesticide type were frequently detected at all sampling site. The total concentration of micropollutants were higher in summer than in winter and measured within the range of ND ～ 36.50㎍/L. Also, because of effect of seomjin river, GY6 of all sampling site detected by the highest concentration, GY10 and 11 located in Gwang-yang outside bay were not detected the micropollutants. From the result of this study, we should estimated that the industrial complex located in Gwang-yang inside bay and an inflow of fresh water through the Seomjin river are major pollution sources of Gwang-yang bay.

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 disinfected with Cl_2, O_3 and ClO_2 after treatment by fluidized-bed system with water added with humic acid(l0㎎/L) were investigated the formation and the removal of trihalomethanes (THMs), and the trace organic by-products by gas chromatography(GC) & gas chromatography/mass selective detector(GC/MSD). Control was used by activated carbon(AC) and water added with hurnic 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, O3 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 adsorption-degradation removal characteristics than that of AC.