This study applied microbubbles to reduce membrane fouling in wastewater reuse membrane processes, evaluated and compared the transmembrane pressure with or without the application of microbubbles and the cleaning efficiency with the application of aeration and microbubbles. In addition, this study analyzed foulants removed from the membrane surface. Changes in the transmembrane pressure of membranes with the presence or absence of microbubbles were observed. As a result, transmembrane pressure (TMP) increasing rate decreased twofold when applying microbubbles to realize stable operations. This study compared and evaluated cleaning efficiency applying aeration and microbubbles. As a result, the cleaning efficiency was 5% higher on average when applying microbubbles. In turbidity and total organic carbon (TOC), foulants were discharged when applying microbubbles twice as much as applying aeration. It is thought that particulate foulants precipitated on the membrane surface were more likely to desorb because the adhesion between the membrane surface and particle was weakened by microbubbles. Therefore, it is considered possible to effectively control membrane fouling because of the increase in cleaning efficiency when applying microbubbles to wastewater reuse membrane processes.

Microfiltration (MF) and Ultrafiltration (UF) membrane processes capable of producing highly purified water have been extensively applied as a pretreatment process in the wastewater reuse field with the improvement of membrane properties and resistance, development of operating protocols, and improvement of technologies of backwashing and physicochemical cleaning, and improvement of scale and antifoulants. However, despite of the development of membrane production and process technologies, fouling still remains unresolved. This study confirmed that foulants such as polysaccharides, proteins and humic substances existed in final treated effluent (secondary effluent) by fluorescence excitation emission matrix (FEEM) and fourier transform infrared spectroscopy (FTIR) analysis. In addition, when constructing ozone oxidation and coagulation processes as a hybrid process, the removal efficiency was 5.8%, 6.9%, 5.9%, and 28.2% higher than that of the single process using coagulation in turbidity, color, dissolved organic carbon (DOC), and UV254, respectively. The reversible and irreversible resistances in applying the hybrid process consisting of ozone oxidation and coagulation processes were lower than those in applying ozone oxidation and coagulation processes separately in UF membrane process. Therefore, it is considered possible to apply ozonation/coagulation as a pretreatment process for stable wastewater reuse by and then contributing to the reduction of fouling when calculating the optimal conditions for ozone oxidation and coagulation and then to applying them to membrane processes.

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.

선박의 해양사고로 유출된 대량의 기름유출로 인한 해양오염 피해규모는 매우 심각하다. 국제해운 역사에 기록되는 대형 해양오염사고의 대부분은 유조선으로 인해 발생하였으며, 이러한 사고로 인해서 연안국들의 해양환경은 파괴되고 어자원은 오염되어 피해주민들이 생계유지의 어려움을 겪는 등 경제적 손실은 이루 말할 수 없이 크다 하겠다. 선박으로 인한 해양오염을 방지하고 해양환경을 보호하기 위한 목적으로 1954년 제정된 OILPOL협약은 기국의 관할권을 보장하고 항만국의 개입을 최소한으로 제한시켰다. 그러나 국제무역과 세계 선복량의 지속적인 성장과 함께 선박의 해양사고로 인한 오염이 경제 그리고 환경에서 예측할 수 없을 만큼의 막대한 피해를 유발시킴에 따라 연안국과 항만국은 관할권을 확대시키고자 노력하였다. 이러한 시대적 요구와 현실적인 문제점을 해결하기 위한 노력으로 1973년 IMO의 MARPOL73/78협약이 제정되었고 1958년 해양법협약 보다 진보된 해양오염방지에 관한 연안국과 항만국의 관할권이 반영된 1982년 UN해양법협약이 제정되었다. 그러나 이러한 국제협약과 달리 외국적 선박의 항만국 통제 집행에 있어서 일방적으로 국내법을 적용함으로써 국제협약의 관할권과 일치되지 않는 집행이 발생하고 있다. 또한, 외국적 선원을 상대로 한 재판과정에서 신병을 확보하기 위한 목적으로 UN해양법협약에 따라 부과되는 보석금이 과도하게 부과되거나 오랜 기간 억류되는 사례가 발생하는 경우도 있다. 따라서 이 논문에서는 외국적 선박의 해양오염사건 분석을 통해서 국가 관할권과 선원의 인권문제와 관련된 국제법적 쟁점을 도출하고 이를 개선하기 위한 방안을 제시하고자 한다.

본 연구는 반추동물용 섬유질배합사료(TMR) 제조업체 의 사료안전관리 인식 및 사료 중 위해인자 오염도를 조사 하기 위해 138개소 TMR 제조시설을 대상으로 약 10개월 동안 설문조사를 실시하였다. 조사표는 총 17개 문항으로 구성하였으며, 얻어진 자료는 기술통계분석, 교차분석 및 신뢰도 검정을 통해 분석하였다. TMR 제조시설의 평균 일 일 생산능력은 81.38톤 이었다. 평균 개업연도는 2004년 및 종사인원은 13.7명이었고, 유통경로는 직접거래가 80.4%로 가장 많았다. 사료안전관리 시스템 도입은 사료안전관리의 제도적 여건이 조성된 후 도입이 필요하다는 인식이 주를 이루었으며, 사료안전관리 시스템 구축을 위해서는 사료안 전정보 제공 및 공유가 가장 필요한 조건으로 나타났다. 사료안전성 및 위해물질 관리에 가장 취약한 분야는 곰팡 이 독소인 것으로 조사되었으며, 사료 제조과정에서 가장 위험한 위해인자는 쇠, 파편, 흙 등과 같은 이물질로 나타 났다. 사료 중 위험인자 오염도 조사에서 카드뮴, 비소 및 셀레늄은 허용기준치를 초과한 제품이 일부 조사되었고, 오크라톡신류 및 아플라톡신류는 허용범위내로 조사되었 다. 잔류농약, BSE, 푸모니신 및 살모넬라는 검출되지 않았 으며, 멜라민 및 비단백태질소화합물은 각각 11.35ppm 및 5%로 최댓값을 나타냈다. 규모별 TMR 제조시설의 사료 내 위해인자 오염도는 규모별로 차이가 많았으며, 같은 규 모 내에서도 제조시설에 따라 위해인자의 검출량이 다르 게 나타났다. 또한 소규모에 비해 중규모 및 대규모에서 위해인자 검출량이 더 높아지는 경향을 보였다. 따라서 본 조사결과 TMR 제조시설의 사료안전관리 시스템을 구축하 기 위해서는 사료안전에 대한 정보제공 및 공유가 정책적 으로 제도화되어야 하고, 사료 내 발생하는 곰팡이 독소방 지 및 이물질 제거를 위한 사료관리법의 강화와 원료 공급 처에서 이물질을 제거할 수 있는 장치 도입을 의무화할 필 요가 있다고 판단된다.

In this study, we analyzed the concentration of cadmium and mercury in urine and lead in blood from 668 residents in the exposed and compared areas in Gwangyang-si and Yeosu-si, from July 2013 to December 2015. According to the lifestyle (past smoking, current smoking, passive smoking, drinking and exercise), the concentration of cadmium in urine was higher in the compared areas than in the exposed areas in Gwangyang. However, the concentration of cadmium in urine according to the lifestyle except drinking was higher in the exposed areas than in the compared areas in Yeosu. According to the past smoking and current smoking, the concentration of mercury in urine was higher in the compared areas than in the exposed areas in Gwangyang, but the passive smoking, drinking and exercise showed similar concentration levels both in the exposed and compared areas in Gwangyang. The concentration of mercury in urine according to the past smoking and current smoking was higher in the exposed areas than in the compared areas in Yeosu, but the concentration of mercury in urine according to the drinking and exercise was lower in the exposed areas than in the compared areas in Yeosu. According to the past smoking, the concentration of lead in blood showed similar concentration levels in the exposed and compared areas in Gwangyang, but regarding current and passive smoking, it was higher in the compared areas than in the exposed areas in Gwangyang. Especially, the concentration of lead in blood according to the drinking in Gwangyang showed statistically significant difference (p<0.05). The concentration of lead in blood according to the lifestyle was higher in the compared areas than in the exposed areas in Yeosu.

본 연구에서는 오염된 점토 내 Cs을 제거하기 위하여, 계면활성제의 소수성 알킬사슬의 길이에 따른 Cs의 탈착특성을 연구 하였다. 양이온성 계면활성제로 Alkyl trimethyl ammonium bromide를 사용하였고, 소수성 알킬사슬은 octyl-, dodecyl-, cetyl- 으로 변화시켰다. 소수성 알킬사슬이 길어질수록 montmorillonite 내 계면활성제의 흡착량이 증가하였고, 계면활성제의 층간 흡착으로 층간거리가 증가하는 것으로 나타났다. Cs의 탈착률도 알킬사슬의 길이가 증가함에 따라 향상되었고 cetyl 그룹을 갖는 양이온성 계면활성제는 최대 99±2.9%의 Cs 제거율을 나타냈다.

To determine the contents of sodium and potassium in side dishes, 92 samples from 22 different kinds of side dishes that can be classified into 3 groups were collected in Seoul area and analysed using ICP-OES. The highest sodium content was detected in pepper doenjang muchim, while potassium content was the highest in kong jorim. When comparing the content of sodium and potassium in 3 groups, namely namul, muchim, and jorim, the sodium content of namul group was significantly different from those of jorim and muchim (p-value < 0.05). Sodium intake per serving size was the highest in parae muchim among the samples as estimated to 20.2% of WHO recommendation that is 2,000 mg/day. The amount of sodium by simultaneously intake of soybean sprouts namul, anchovy jorim and parae muchim per one serving size was estimated to 1,000 mg. The potassim/sodium ratios of spinach namul and kong jorim were 1.70 and 0.81, respectively, while that of bracken namul was very low as about 0.1. Foodborne pathogens were not detected out of 92 side dishes.

To estimate pollution sources in the watershed with various industries, the simulation of contamination route and distribution of 2-methyl-4,6-dinitriophenol(DNOC) were performed with a numerical model Hydro Geo Sphere. This study was performed calculations of the load using the measured concentration and simulated flow rate. And, the river was divided by the sampling sites at the mainstream, and the contribution rate at downstream sampling sites was calculated for each section. The results showed the concentration of the downstream sampling sites were decided by the concentration of upstream sites, and the contribution rates of the tributaries were calculated below 10%. The results also showed that the impact of the potential sources in Section 1(Geumho1 ~ Geumho2) and Section 5(Geumho5 ~ Geumho6) was larger than in the other area. In Section1 and Section5, It seemed to require detailed investigation.

The purpose of this study was to investigate the effects of ionized calcium treatment on total bacterial cross-contamination of chicken carcass surface in the slaughtering process. The growth of Escherichia coli was strongly inhibited in a medium prepared by using a 0.5% ionized calcium solution. The total bacterial cross-contamination of chicken carcass surface and the scalding water was significantly increased as the number of scalding was increased (p<0.05). The total bacterial cross-contamination of chicken carcass surface reached a plateau without a further increase as scalding was performed consecutively for 10 or more times. The total bacterial cross-contamination of the scalding water was significantly increased as the number of scalding was increased (p<0.05). The total bacterial cross-contamination of chicken carcass surface of the chickens raised on a floor type farm was significantly higher than that of the chickens raised in a battery cages (p<0.05). The total bacterial cross-contamination of chicken carcass surface of the chickens raised on a floor type farm was significantly lower in the 0.5% ionized calcium solution treatment group than in the control group (p<0.05).

In this study, we investigated influent and effluent water pollutants in 53 Public Sewage Treatment Works (PSTWs) where industrial wastewater or landfill leachate is combined four times for two years from 2014 to 2015. Also, we analyzed the characteristics of heavy metals and volatile organic carbons at influent and effluent of these PSTWs caused by sewage treatment combined with industrial wastewater or landfill leachate. As a result, six heavy metals such as barium, copper, iron, manganese, nickel and zinc, and four volatile organic carbons (VOCs) including phenols, di(2-)ethylhexyl phthalate (DEHP), formaldehyde and toluene were observed above detection limits in most of PSTWs. Also, it was revealed that six heavy metals such as hexavalent chromium, mercury, cadmium, chromium, nickel and selenium, and four VOCs including 1,1-dichloroethylene, vinyl chloride, naphthalene, and epichlorohydrin were observed more frequently according to precipitation. As a result of reviewing the monitoring data on “Water Quality Monitoring Networks” in lower watersheds of PSTWs, both heavy metals and VOCs were below detection limits, indicating that the effluent water had little influence on the watershed. Nevertheless for the better management of influent and effluent pollutants in PSTWs, it is necessary to establish the advanced management plans for water pollutants in PSTWs, which include a list of priority substances management, monitoring plans, and guidelines for industrial wastewater and landfill leachate combined in PSTWs.

A membrane module including grid was designed and introduced to MBR (membrane bio-reactor) for the purpose of better control of membrane fouling. It could be anticipated that the grid enhances the shear force of fluid-air mixture into the membrane surface by even-distributing the fluid-air to the membrane module. As MLSS concentration, packing density which is expressed in the ratio of the housing and the cross-sectional area of membrane fibers (Am/At) and air-flow rate were changed, membrane foulings were checked by monitoring fouling resistances. The total fouling resistance (Rc+Rf) without grid installation (i.e., control) was 2.13×1012 m-1 , whereas it was reduced to 1.69×1012 m-1 after the grid was installed. Regardless of the grid installation, the Rc+Rf increased as the packing density increased from 0.09 to 0.28, however, the increment of resistance for the grid installation was less than that of the control. Increase in the air flow rate did not always guarantee the reduction of fouling resistance, indicating that the higher air flow rate can partially de-flocculate the activated sludge flocs, which led to severer membrane fouling. Consequently, installation of grids inside the housing have brought a beneficial effect on membrane fouling and optimum air flow rate is important to keep the membrane lowering fouling.

본 연구는 상추와 오이의 GAP 인증 및 미인증 농가를 대상으로 토양, 용수, 작물 (상추, 오이), 장갑, 포장재 (비닐)에 대한 미생물 오염도를 비교·평가하고 농가의 위생관리 실태를 조사하여 GAP 인증 농가에 대한 미생물학적 안전성 강화를 위한 자료로 활용하고자 하였다. 미생물 오염도 조사 결과 상추 농장의 경우 위생지표세균 오염도는 GAP 인증 농가가 미인증 농가 보다 조금 낮거나 유사하였고, 병원성미생물인 S. aureus와 B. cereus는 GAP 인증 농가의 토양과 용수에서 미인증 농가 보다 높게 검출되었다. 오이농장은 토양의 대장균군과 B. cereus, 장갑의 일반세균 및 대장균군 오염도가 GAP 미인증 농가보다 GAP인증 농가에서 높았고, 그 외에는 GAP 인증 농가와 미인증 농가가 유사한 오염도를 나타내었다. 전체적으로 결과를 비교했을 때 GAP 인증 농가와 미인증 농가의 미생물 오염도 수준이 크게 차이가 나지 않는 것으로 확인되어 GAP를 인증 받았음에도 불구하고 미생물에 대한 관리는 미흡한 것으로 나타났다. 농가의 위생관리 실태 조사 결과에서는 GAP 인증 농가가 미인증 농가보다는 미생물 오염을 방지하기 위한 노력들을 하고 있는 것으로 확인되었으나, GAP 인증 및 미인증 농가 모두 농업용수의 관리와 작업 시 사용되는 작업자의 장갑 관리에 있어서는 미흡한 것으로 확인되었다. 이상의 연구결과는 농산물의 미생물 오염방지에 대한 방안을 제시하고 GAP 인증을 개선하는데 기초자료로 활용될 수 있을 것으로 판단된다.

본 연구는 수입에 의존하고 있는 꽃가루의 안전성을 검토하기 위하여 수행되었다. 수입된 사과 꽃가루에서 동정된 세균은 6종류로 나타났으며, 복숭아 꽃가루에서는 4종 배 꽃가루에서는 5종 키위 꽃가루에서는 5종의 세균이 검출되었다. 이 중 사과와 복숭아에서 분리된 Pantoea ananatis와 Pantoea agglomera는 2007년 검역대상 병으로 고시되었다가 현재는 국내에서 발견되어 보고되어있는 세균이다. 꽃가루에서 분리된 세균 20종을 담배에 접종하여 과민성반응을 조사한 결과 총 9종의 세균이 과민성반응을 일으키는 것으로 나타났다. 아세톤 처리에 따른 세균의 밀도는 대조구와 비교하여 감소하는것으로 나타났다. 아세톤을 처리한 후 발아율을 검정한 결과 사과 꽃가루는 37%에서 13%로 발아율이 떨어졌으며, 복숭아는 39%에서 22%로 떨어졌다. 배 꽃가루 역시 32%에서 19%로 발아율이 떨어졌으며키위의 38%에서 3%로 가장 많이 떨어지는 것으로 나타났다.