• 상하수도학회지
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• 제22권1호
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• pp.141-148
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• 2008

This study was conducted to evaluate the effect of PAC(Powder Activated Carbon) retention time on stable operation of high concentration powered activated carbon(HCPAC-MBR) in the treatment of secondary domestic wastewater. The pilot scale HCPAC-MBR system was operated at two different SRTs, 25 days and 100 days. The main drawback of HCPAC-MBR system was the rapid increase of trans-membrane pressure. The increase rate of trans-membrane pressure was proportional to SRT value at constant flux. This result seemed to be caused by reduced amount of EPS adsorbed on the PAC in the reactor by decreasing the SRT of the PAC. The particle size of the PAC was also influenced by SRT. The PAC size was decreased as SRT was increased. The change of particle size could be one reason for the change of trans-membrane pressure. The pore volume in the cake-layer formed on the membrane surface became to be increased by reducing SRT, because the cake-layer was highly composed of the PAC. Therefore, increased pore volume might play a role to reduce the trans-membrane pressure. The removal rate of E260 and TOC was also inversely proportional to SRT value.

• 멤브레인
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• 제24권1호
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• pp.63-68
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• 2014

주류를 제외한 과일 및 탄산음료 등을 제조하는 비알코올성 음료품 제조시설에서 발생되는 폐수는 높은 농도의 유기물과 낮은 농도의 질소, 인 등을 함유한다. 이러한 폐수의 처리 시설은 주로 호기성 공정과 약품응집 공정으로 구성하고 후단에 사여과지 또는 활성탄 공정을 추가하기도 한다. 하지만 이러한 방식은 긴 체류시간과 침전지 설치로 인해 많은 부지를 필요로 하는 문제가 있다. 본 연구에서는 부지소요 문제와 슬러지 유출로 인한 수질저하 문제를 해결하고자 W식품공장 폐수처리장 인근에 MBR pilot plant를 설치하고 장기간 운영을 통해 데이터를 확보하고 처리 효율을 평가하였다. 약 3개월간 음료수 제조공정 폐수를 평막을 적용한 MBR pilot plant로 운전조건을 변화하며 처리한 결과, 처리유량 $20m^3/day$, HRT 29 hr, 4Q 반송조건까지는 유기물 제거율 97% 이상으로 안정적인 처리가 가능했다. 하지만 그 이상의 운전조건에서는 생물반응조의 오염물질 제거율이 감소하였고 TMP가 급격히 증가하는 모습을 보였다.

• 대한환경공학회지
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• 제22권12호
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• pp.2125-2134
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• 2000

본 연구는 매립지에서 발생되는 침출수를 배출허용기준 이내로 처리함은 물론 경제적인 처리 공정을 개발하기 위한 것이다. 이를 위해 현장 pilot test 이전에 최적 공정 선정과 장치 설계인자를 도출하기 위해 실험실에서 기초실험을 수행하였다. 본 연구에서 개발하고자하는 처리공정은 역삼투시스템을 이용하는 공정인데 전처리로서 침지형분리막 생물반응기를 이용하였으며, 역삼투시스템에서 발생되는 농축수는 매립가스를 열원으로 하는 직화식 증발기를 이용하여 처리하는 공정이다. 실험결과 침지형분리막 생물반응기에서 SS, $BOD_5$, $COD_{cr}$, $NH_4{^+}-N$은 각각 99.0%, 43.0%, 12.9%, 48.5%, 18.7%의 제거효율을 보였다. 역삼투시스템온 $BOD_5$, $COD_{cr}$, $NH_4{^+}-N$, T-N을 각각 97.5%, 97.6%, 79.7%, 85.4% 제거할 수 있었다. 증발기는 $COD_{cr}$, $NH_4{^+}-N$, T-N을 각각 90.5%, 50.6%, 63.3% 제거할 수 있었으나 배출허용기준 이내로 처리하기는 어려운 것으로 나타나 응축수는 역삼투시스템 전단으로 보내서 전처리수와 함께 처리되어야할 것으로 나타났다.

• Advances in environmental research
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• 제2권1호
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• pp.1-8
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• 2013

There is a significant demand to make various dissolved gases in water. However, the conventional aeration method shows low gas mass transfer rate and gas utilization efficiency. In this study, a novel rotating wheel entraining gas method was developed for making high dissolved $O_2$ and $O_3$ in water. It produced higher concentration and higher transfer rate of dissolved $O_2$ and $O_3$ than conventional bubble aeration method, especially almost 100% of gas transfer efficiency was achieved for $O_3$ in enclosed reactor. For application of rotating wheel entraining gas method, aerobic bio-reactor and membrane bio-reactor (MBR) were successfully used for treatment of domestic and pharmaceutical wastewater, respectively; and vacuum ultraviolet $(VUV)/UV+O_3/O_2$ reactors were well used for sterilization in air/water, removal of dust particles and toxic gases in air, and degradation of pesticide residue and sterilization on fruits and vegetables.

• 한국염색가공학회지
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• 제30권1호
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• pp.51-61
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• 2018

In this study, effluent water was produced through Submerged Membrane Bio-Reactor(SMBR) process, which is a simple system and decomposes organic matter contained in wastewater with biological treatment process and performs solid-liquid separation, Especially, ozone oxidation treatment process is applied to effluent water containing fluorescent whitening agent, which is a trace pollutant which is not removed by biological treatment, and influences the quality of reused water. The concentration of $COD_{Cr}$ in the SMBR was $449.3mg/{\ell}-COD_{Cr}$, and the concentration of permeate water was $100.3mg/{\ell}-COD_{Cr}$. The removal efficiency was about 70.1%. The amount of ozone required for the removal of the fluorescent whitening agent in the permeated water in SMBR was $6.67g-O_3/min$, and the amount of ozone required to remove $COD_{Mn}$ relative to the permeate water was calculated to remove $0.997mg-COD_{Mn}$ for 1mg of $O_3$.

• 한국환경과학회지
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• 제25권6호
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• pp.817-827
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• 2016

The resistance in series model has been frequently used for determination of various filtration resistance to correctly understand the membrane fouling behaviour in MBR (membrane bio-reactor) for wastewater treatment. The cake layer resistance ($R_c$) which is commonly determined by calculation of flux dataset that are obtained empirically before and after removing the cake layer on membrane surface. However, the calculated Rc values are very dependent on the cleaning methods adapted for removal of cake layer. This study investigated how the various cleaning options affect $R_c$. Seven different cleaning methods were employed: i) ultrasonication (100 W, 10 min), ii) ultrasonication (200 W, 60 min), iii) ultrasonication (400 W, 120 min), iv) water rinsing in a shaker (100 rpm, 10 min), v) water rinsing in a shaker (300 rpm, 60 min), vi) water rinsing, vii) sponge scrubbing. For the hydrophilic PES membrane, the cake layer removal efficiencies ranged from 64% to 10%, indicating that the removal of cake layer was highly dependent on the cleaning options. For the hydrophobic PVDF membrane, the cake layer removal efficiencies ranged from 79% to 97%. Consequently, a standardized method for cake layer removal to determine cake resistance ($R_c$) is needed for correct interpretation of the fouling phenomena.

• 한국물환경학회지
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• 제22권5호
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• pp.865-870
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• 2006

The behavior and influence of EPS on membrane fouling by changing of hydraulic retention time was investigated, using lab. scale submerged membrane bio-reactor, which was operated with gravitational filtration and fed supernatant of primary sedimentation in waste water treatment plant as influent. The membrane was adopted micro-filter of polyethylene hollow fiber. EPS was analysed as polysaccharides and protein especially, into soluble and bound EPS separately. The concentration of soluble EPS was increased at short HRT, then membrane fouling was rapidly progressed and flux was depressed. The most of EPS clogged membrane pore were polysaccharides, while protein was important parameter affected on membrane fouling because of it's more accumulating in the more term operating.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2008년도 추계학술발표회 발표논문집
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• pp.515-516
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• 2008

MBR공정에서 막 오염을 제어하기 위하여 분리막 모듈에 원통형 관을 도입하여 각각 공기공급량과 MLSS농도, 분리막 면적에 따른 막 오염 정도를 나타내는 TMP를 분석하였다. 원통형 관을 사용하지 않은 대조군보다 원통형 관을 사용한 M$_1$과 M$_2$ 경우에 운전 종료 시점이 연장된 것을 확인할 수 있었고 공기공급량과 MLSS농도, 분리막 면적의 변화에 따른 TMP의 변화가 생기는 것을 확인할 수 있었다.

• 공업화학
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• 제25권4호
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• pp.401-408
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• 2014

분리막 생물반응기에서 산기량 제어는 반응기 내 유체흐름과 특히 막표면 근방에서의 전단응력을 변화시켜 막오염 감소 및 에너지 절약을 구현하는 중요 독립변수 중 하나이다. 본 연구에서는 원통형 생물 반응기 중심에 침지형 평막을 장착하고 하부에서 공기가 공급되는 3차원적 시스템에 대하여 "COMSOL"프로그램을 사용하여 수치해석하였다. 용액의 점도, 온도는 일정하다고 가정했으며 투과액 부피와 산기량의 비인 $SAD_p$를 변수로 사용하였다. 유속센서, 동영상 이미지분석으로 측정한 유속과 수치해석 결과는 11% 이내에서 일치함을 확인하였다. 반응기 내 유체의 흐름은 산기관과 막모듈 구간에서 급격하게 증가하였으나 막모듈을 지나면서 감소하였으며 반응조 벽에서 중심축 방향으로 갈수록 유속이 증가하는 경향을 보였다. 막 표면에서 계산된 전단응력은 하단 중앙부가 가장 크게 나타났으며 산기량이 증가할수록 전단응력이 증가하였다. 특히 산기량을 0.15에서 0.25 L/min로 증가할 경우 크게 증가함을 확인할 수 있었다.

• 한국환경농학회지
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• 제28권4호
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• pp.371-377
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• 2009

In this study, simultaneous nitrification and denitrification (SND) from synthetic wastewater were performed to evaluate dissolved oxygen(DO) effects on chemical oxygen demand(COD) and nitrogen removal in a single membarne bio-reactor(MBR). DO levels in MBR at Run 1, 2, and 3 were 1.9~2.2, 1.3~1.6, and 0.7~1.0 mg/L, respectively. Experimental results indicated that DO had an important factor to affect COD and total nitrogen(TN) removal. SND were able to be accomplished in the continuous-aeration MBR by controlling ambient DO concentration. It is postulated that, because of the oxygen diffusion limitation, an anoxic micro-zone was formed inside the flocs where the denitrification might occur. From the results of this study, 96% of COD could be removed at DO of 0.7mg/L. At run 2 72.92% of nitrogen was removed by the mechanisms of SND (7.75mg-TN/L in effluent). In this study, SND was successfully occurred in a MBR due to high MLSS that could help to form anoxic zone inside microbial floc at bulk DO concentrations of 1.3~1.6mg/L.