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.

Total organic carbon(TOC) was introduced as the water quality index of the rivers and lakes in 2013. This paper evaluated factors affecting effluent TOC concentrations and treated and discharged loads of existing publicly owned treatment works(POTWs). For selected POTWs with greater treatment capacity than 500㎥/day, factorial analysis was used to consider effects of kinds of biological treatment processes, inflow of other types of wastewater(industrial, livestock, landfill leachate wastewater, etc.) with domestic wastewater, sewer separation rate, and effluent discharging zones in which different effluent criteria applied. As a result, those factors did not show significant effect on effluent TOC concentration of POTWs in effluent discharging zone Ⅰ and Ⅱ. However, In effluent discharging zone Ⅲ and Ⅳ, kinds of biological treatment processes, the inclusion of other waste in influent of domestic wastewater, and the sewer separation rate were significant factors. The treated TOC load in POTWs was also not affected significantly by the variables set in this study. On the other hand, those three factors influenced significantly on the TOC load discharged to water bodies. The sum of factorial effects and the contribution rate of three factors to the discharged TOC load was 60.23 and 41%, 59.57 and 41%, and 42.04 and 18%, respectively.

This study investigated phosphorus removal from secondary treated effluent using coagulation-membrane separation hybrid treatment to satisfy strict regulation in wastewater treatment. The membrane separation process was used to remove suspended phosphorus particles after coagulation/settlement. Membrane separation with 0.2 μm pore size of micro filtration membrane could reduce phosphorus concentration to 0.02 mg P/L after coagulation with 1 mg Al/L dose of polyaluminum chloride (PACl). Regardless of coagulant, the residual concentration of phosphorus decreased as the dose increased from 1.5 to 3.5 mg Al/L, while the target concentration of 0.05 mg P/L or less was achieved at 2.5 mg Al/L for the aluminum sulfate (Alum) and 3.5 mg Al/L for PACl. Moreover, alum showed better membrane flux as make bigger particles than PACl. Alum showed a 40% of flux decrease at 2.5 mg Al/L dose, while PACl indicated a 50% decrease of membrane flux even with a higher dose of 3.5 mg Al/L. Thus, alum was more effective coagulant than PACl considering phosphorus removal and membrane flux as well as its dose. Consequently, the coagulation-membrane separation hybrid treatment could be mitigate regulation on phosphorus removal as unsettleable phosphorus particles were effectively removed by membrane after coagulation.

This study was conducted to provide basic data for establishing water pollution prevention for effluent water from soil and stone quarries and downstream river water by investigating waste water and sewage water processing, as well as the state of legislation related to grit chamber installation and water quality analysis. The pH and DO, BOD, T-P, Total coilform of effluent water and stream water showed higher than Ⅲ class but COD and SS, T-N showed less than Ⅲ class. In addition, concentration of BOD and COD, Turbidity were increased following deepened rainfall intensity. And therefore we devise systematic reduction facility and remedy for prevention of water pollution.

Euiam and Paldang Reservoirs have often been facing water quality problems, such as eutrophication, algal blooms and off-flavors by treated wastewater effluent (TWE) in the North-Han and the Han River basins, but little is examined on the direct biological effect of TWE. This study tested algal growth potential (AGP) of four TWEs discharged into Euiam and Paldang Reservoirs to evaluate water fertility in September 2014 and March and September 2015. Test alga was used Anabaena circinalis isolated from Paldang Reservoir. Mean concentration of T-N and T-P in TWEs was 3,956.7 μg N L-1 and 50.8 μg P L-1, and the proportion of NO3-N and PO4-P to the total fraction was 72.1% and 40.8%, respectively. Both N and P were high in TWEs, but much higher N than P concentration indicates strong P-limitation. As a consequence, the maximum AGP was determined by PO4-P concentration (r=0.998, p<0.01). Mean AGP value was 15.4 mg dw L-1 among four effluents indicating its eutrophic condition. Due to the establishment of tertiary (advanced T-P) treatment method in the studied plants recently, P concentration was significantly decreased in TWEs compared to the years prior to 2012. However, P concentration seems to be still high enough to cause eutrophication and algal blooms. Therefore, wastewater treatment to P-free level needs to be considered if effluents are directly discharged into the drinking water resources.

Daecheong Reservoir was made by the construction of a large dam (>15 m in height) on the middle to downstream of the Geum River and the discharge systems have the watergate-spillway (WS), a hydropower penstock (HPP), and two intake towers. The purpose of this study was to investigate the limnological anomalies of turbid water reduction, green algae phenomenon, and oligotrophic state in the lower part of reservoir dam site, and compared with hydro-meteorological factors. Field surveys were conducted in two stations of near dam and the outlet of HPP with one week intervals from January to December 2000. Rainfall was closely related to the fluctuations of inflow, outflow and water level. The rainfall pattern was depended on the storm of monsoon and typhoon, and the increase of discharge and turbidity responded more strongly to the intensity than the frequency. Water temperature and DO fluctuations within the reservoir water layer were influenced by meteorological and hydrological events, and these were mainly caused by water level fluctuation based on temperature stratification, density current and discharge types. The discharges of WS and HPP induced to the flow of water bodies and the outflows of turbid water and nutrients such as nitrogen and phosphorus, respectively. Especially, when hypoxic or low-oxygen condition was present in the bottom water, the discharge through HPP has contributed significantly to the outflow of phosphorus released from the sediment into the downstream of dam. In addition, HPP effluent which be continuously operated throughout the year, was the main factor that could change to a low trophic level in the downreservoir (lacustrine zone). And water-bloom (green-tide) occurring in the lower part of reservoir was the result that the water body of upreservoir being transported and diffused toward the downreseroir, when discharging through the WS. Finally, the hydropower effluent was included the importance and dynamics that could have a temporal and spatial impacts on the physical, chemical and biological factors of the reservoir ecosystem.

As the Enforcement Ordinance of Environmental Policy Act was revised in 2013, total organic carbon(TOC) was added as an indicative parameter for organic matter in Water and Aquatic Ecosystem Environmental Criteria. Under these imminent circumstances, a regulatory standard is needed to achieve the proposed TOC limitation control water quality from the public sewage treatment plants(PSTWs). This study purposes to present the determination method for TOC effluent limitation at the PSTWs. Therefore we investigate the TOC effluent limitation of foreign countries such as EU, Germany and USA, and analyse the effluent water qualities of PSTWs. In using these TOC data, we review apprehensively the statistics-based, the technology-based, and the region(water quality)-based determination method of TOC effluent limitation for PSTWs.

The development of alternative water resources has emerged as an effective method for solving drought of water resources due to extreme weather and increase in water consumption. Recently, in Korea, there has been active research on reverse osmosis desalination technology, wastewater reuse using forward osmosis membranes, and the forward osmosis(FO)-reverse osmosis(RO) hybrid process combining these two technologies. In this study, the basic performance of FO membranes manufactured by three domestic and international manufactures such as Microfilter Co., Ltd., Toray Chemical Korea Inc., and Hydration Technologies Inc., were investigated for wastewater reuse. In addition, as an experiment to select feed solution, the selected membranes were operated 48 consecutive hours using three secondary effluents pretreated by the UF membrane with a pore size of 0.1 μm and auto strainer with pore sizes of 1 μm and 100 μm as feed solution. Although there was not much difference in the operating performance. Thus, the treated water using the 100 μm auto strainer was selected as feed solution applied to the assessment.

본 연구는 자외선 광분해에 의한 비스페놀 A (BPA)의 에 스트로겐 활성 저감에 미치는 하수처리장 방류수 유기물질 의 영향을 조사하였다. 방류수 유기물질과 표준으로 사용한 스와니강 자연 유기물질은 극성에 따라 소수성, 반친수성, 친수성 분획으로 분리하였다. 특이 자외선 흡수 (SUVA) 분 석 결과, 방류수 유기물질은 높는 소수성을 가지고 있는 자 연 유기물질과 다르게 소수성이 낮은 미생물 기원 유기물 질과 유사한 특성을 나타내었다. 3시간의 자외선 조사는 방 류수 및 자연 유기물질의 극성에 따라 SUVA 값을 유의하 게 감소시켰다 (p<0.0001). 유기물질이 없는 조건에서, BPA (5.0×10-5 M)의 상대 에스트로겐 활성도는 자외선 광분해 에 의해 86%에서 63%로 감소하였다. 그러나 유기물질이 있 는 조건에서 상대 에스트로겐 활성도는 평균적으로 68%에 서 37%로 감소하였으며, 유기물질의 종류 (방류수 또는 자연 유기물질) 및 극성 (소수성, 반친수성, 친수성)과 유의한 차이 를 나타내지 않았다 (p>0.05). 결과적으로, 유기물질이 있고 없는 조건에서 자외선 광분해에 의해 감소한 BPA의 상대 에스트로겐 활성도는 각각 31%와 23%였으며, 이것은 방류 수와 자연 유기물질 모두 광분해에 의한 BPA의 에스트로겐 활성 저감을 촉진시킨다는 것을 제시한다.

In accordance with the Watershed Sewer System Maintenance Plan enforced on February 2, 2013, the different compliance concentration of effluent limit be applied to effluent discharged from public sewage treatment works(PSTWs) in each watershed on the basis of water quality thereof. With the introduction of watershed sewer system, it is necessary to set the compliance concentration of effluent limit for PSTWs situated in the watershed, by region and PSTW size, to achieve water quality criteria for regional watersheds or target water quality under TMDL program. Watershed Environmental Agencies establish the Watershed Sewer System Maintenance Plan and set the compliance concentrations of effluent limit for PSTWs under the plan. The agencies plan to apply tougher effluent BOD concentration limits in Class Ⅰ to Ⅳ areas. Effluent BOD concentration limits will be toughened from 5~10 mg/L to 3 mg/L in class Ⅱ~Ⅲ areas, from 10mg/L to 5mg/L in class Ⅳ areas. Uniform application of effluent BOD concentration limits to PSTWs in the watershed sewer system need to be complemented considering type of sewage treatment technology employed and watershed characteristics. Therefore, this study presents method to determine the compliance concentration of effluent limit from PSTWs in the watershed.

하수방류수 재이용을 위한 RO 전처리로 부유물질 및 콜로이드 물질의 제거를 위해 가압식 MF를 사용하였다. 남양주 J 하수처리장의 생물학적 처리와 모래여과를 거쳐 방류되는 방류수를 원수로 사용하였으며 100 톤/일 규모의 pilot plant를 1년 이상 운전하여 성능을 검토하였다. 가압식 MF에 의해 원수 수질 및 온도의 변화에 상관없이 flux 40 LMH 운전이 가능하였으며 전처리로 응집제를 넣어 용존 유기물을 응집할 경우 60 LMH 운전이 가능하였다. RO 공정에서 장기간 정지 이후 운전을 재개하였을 때 1단 pressure drop이 급격히 증가하는 현상이 나타났고 이러한 결과는 배관 내 형성된 유기물과 이온물질의 복합오염물질이 1단 RO막에 침적된 결과로 사료된다.

So many drinking water treatment plants are under various difficulties by new reinforced effluent standards. Since the target turbidity, much higher than annual average, for designing sludge thickener have to be set to confront high turbidity season, the sludge at thickener should be put up for a long time during usual days. So the soluble manganese and chloroform may be formed under the anaerobic environment in the sludge thickener when the sludge retention time is longer with low turbidity. This phenomenon results in difficulties to keep regulatory level of the discharged effluent. For an effort to overcome the problems, a sludge aeration was successfully implemented into the thickening process. As a result, the final effluent quality and sludge volume were much improved; 41 % of manganese, 62 % of chloroform and 35 % of sludge volume. Additionally, effluent quality was improved ; 61 % of Manganese on aeration with pH control and we could make sure of stability effluent quality despite a long sludge retention time. We recommended the standard of installation sludge aeration equipment to nationally supply water treatment plant under effluent water quality problem ; Manganese, Chloroform, etc.

Study on effluent organic matter (EfOM) characteristic and removal efficiency is required, because EfOM is important in regard to the stability of effluents reuse, quality issues of artificial recharge and water conservation of aqueous system. UV technology is widely used in wastewater treatment. Many reports have been conducted on microbial disinfection and micro pollutant reduction with UV treatment. However, the study on EfOM with UV has limited because low/medium pressure UV lamp is not sufficient to affect refractory organics. The high intensity of pulsed UV would mineralize EfOM itself as well as change the characteristics of EfOM. Chlorine demand and DBPs formation is affected on the changed amounts and properties of EfOM. The objective of this study is to investigate the effect on EfOM, chlorine residual, and chlorinated DBPs formation with low pressure and pulsed UV treatment. The removal of organic matter through low pressure UV treatment is insignificant effect. Pulsed UV treatment effectively removes/transforms EfOM. As a result, the chlorine consumption is changed and chlorine DBPs formation is decreased. However, excessive UV treatment caused problems of increasing chlorine consumption and generating unknown by-products.

Most small laundry factory has been operated without not only environmental expertise but also technical process. The objective of this study is to get the optimal coagulation dosage for satisfaction of discharge permission standard of laundry wastewater treatment plant(WTP) effluents by jar test.The coagulants are alum and sodium hydroxide(NaOH), coagulants aids is polymer. Also, the best coagulation reaction was shown in the following conditions ; Alum 4.13g/L, NaOH 1.03g/L, Polymer 0.27g/L on average. The optimal coagulation dosage could be reduced costs to 4.43 million won a year. It was considered that operating a small WTP was an important technical data in same industry.

본 연구는 하수처리장 방류수가 하천 유기물 오염에 미치는 영향을 파악하기 위하여 구미시 관내에 위치한 구미 4단지, 구미, 구미 원평하수처리장 방류수와 처리장 상∙하류 하천을 조사하였다. TOC 중 DOC가 70% 이상 으로 대부분 용존성으로 존재하였고, TOC에 대한 BOD, CODMn의 산화율은 각각 13~43%, 37~73%로 나타났다. 하지만 현재 사용되고 있는 BOD, CODMn이 총 유기탄소 에서 차지하는 비율이 약 50% 이하로 나타나, 유기물을 대표하는 데 어려움이 있을 것으로 보이며, 향후 TOC로 지표를 전환하는 방향도 모색해 보아야 할 것으로 판단 된다. DOC 분해실험 결과 DOC 중 R-DOC가 70% 이상 으로 난분해성 유기물이 대부분을 차지하는 것으로 나타 났다. 하수처리장 방류수의 유기물이 하천에 미치는 영향 을 보면, 낙동강 하류에서 구미 4단지, 구미, 구미 원평하 수처리장 방류수의 총 TOC 부하량이 차지하는 비율은 15%로 나타났다. 총 비율은 15%로 비교적 많은 부분을 차지하지는 않았지만 이 중 생분해성 유기물보다 난분해 성 유기물이 더 많은 부분을 차지하는 것으로 나타나, 상 수 처리 시 소독부산물의 전구물질이 증가하는 원인으로 작용할 수 있을 것으로 판단된다.

본 연구는 영산강유역 농공폐수처리장 방류수중의 유기오염물질 분포를 관찰하였다. 시료채취 지점은 영산강 유역에 존재하는 4지점의 농공단지 폐수처리장을 선정하였다. 본 연구에서 GC-Ion trap MS로 300종의 일반적인 화학물질을 ppt수준에서 검출할 수 있는 방법을 이용하여 분석하였다. 농공폐수처리방류수에서 검출된 주요 유기오염물질은 농약류, CH구조의 방향족, CHO구조의 프탈레이트류, 그리고 CHO(N) 구조의 아로메틱 아민류였다. 또한 diethylphthalate를 포함한 17종의 내분비계장애물질이 검출되었다. XTT assay를 이용한 세포독성 결과는 TV로 나타냈으며, 그들의 세포독성은 A지점에서 27.2, D지점에서 24.4로 가장 높게 나타났다. 한편 화학적 분석 결과와 생물학적 독성도와는 일치하지 않는 것으로 나타났다.

본 연구는 한외여과 중공사형 모듈과 역삼투 나권형 모듈로 구성된 모듈 set 1∼7을 이용하여 모듈 set에 따른 순수 및 2차 처리수의 투과 flux를 고찰하고, 적용압력과 온도변화에 의한 한외여과 막과 역삼투 막의 분리 특성을 고찰하였다. 탁도와 SS는 한외여과 막에서 효율적으로 제거되며 COD, T-N, TDS 등은 역삼투 막에서 우수한 제거효율을 나타내었다. 적용압력과 온도의 증가에 따른 투과 flux는 선형적으로 증가하는 경향을 보였다. 이로부터 한외여과 및 역삼투 막은 정유공장 방류수의 고도처리 및 재활용을 위해 적합한 것으로 나타났다.

In this study, the antibiotic components in the final effluent from the 12 wastewater treatment facilities located in the Nakdong River basin were investigated, and the correlation between organic matters, nutrients and antibiotics was analyzed. In the final effluent of the wastewater treatment facilities, three sulfonamides antibiotics (sulfamethazine, sulfathiazole, sulfachlorpyridazine) and tetracyclines antibiotics (oxytetracycline, doxycycline) were detected. Sulfamethazine were detected at all points and ranged from 10.398 to 278.784 ng/L. Sulfathiazole were detected at 6 points (Andong, Gumi, Hapcheon, Miryang, Uiryeong, Haman), and ranged from 23.773 to 144.468 ng/L. The correlation coefficients between sulfathiazole and TSS, COD, TOC, NH3-N, NO2-N, and T-N components were high in the range of 0.73 to 0.92. The correlation coefficient between sulfamethazine and T-N was 0.48, and the correlation with the rest of the water quality components was low. The correlation coefficient between sulfamethazine and sulfathiazole was 0.78. Through this study, it was confirmed that the concentration of sulfonamides antibiotics was higher than the concentration of tetracyclines antibiotics in the final effluent of 12 wastewater treatment facilities in the Nakdong River basin, and the concentration of sulfathiazole increased with organic matters and nutrients.

In this study, the organic matter of effluents from sewage treatment plants, located in the Nakdong watershed was investigated. Regression equations were computed using treated sewage data to convert the chemical oxygen demand(COD) concentrations, which are mostly available from an open database, into total organic carbon(TOC) concentrations. The average concentration of organic matter in the sewage treatment plant effluents were 2.2 16.8 mg/L for COD and 3.4 14.3 mg/L for TOC. The concentrations of COD were positively correlated with the TOC concentrations. The correlation between COD and TOC was relatively high, at 0.865(p<0.01). Based on these results, regression analysis was conducted. The regression equation for TOC was 1.651×CODMn-0.084 (R2=0.84). Furthermore, organic matter-related databases for more sewage treatment plants need to be built in order to establish TOC standards and manage the water quality.