• 상하수도학회지
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• 제14권4호
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• pp.350-355
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• 2000

Powdered activated carbon(PAC) is widely used to control 2-MIB와 geosmin causing earthy-musty odor in water supplies. It was known that chlorine is one of the chemicals often come into contact with activated carbon. But activated carbon react with chlorine and surface oxide accumulate on carbon surface. As result, adsorption capacity of activated carbon is reduced. To investigate the effect of chlorine on the PAC's ability to adsorb 2-MIB and Geosmin, a series of experiments was carried out to show (1) the effect of aqueous chlorine doses on the ability of PAC to adsorb 2-MIB and Geosmin from Lake Heodong water. (2) the effect of delaying the chlorine addition after PAC had been added (to simulate the effect of using an alternative point of chlorine addition). As a result of experiment, as chlorine dose increased correspondingly decreased the capacity of activated carbon to adsorb 2-MIB and geosmin. Even though previously adsorbed 2-MIB and geosmin released, as result of the application of delaying the chlorine adding was more beneficial than simultaneous adding chlorine with PAC.

• 상하수도학회지
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• 제18권2호
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• pp.208-214
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• 2004

Dissolved air flotation (DAF) is an effective solid/liquid separation process for low density floc particles such as algal, color-alum and clay-alum flocs produced from low turbidity water. The removal of taste and odor-causing organics (2-mthylisoboneol and geosmin) originating from algae in drinking water is a local and worldwide concern. Although DAF has been effectively applied for the removal of suspended solid, its application for the treatment of dissolved organic carbon is very limited. In this study, a new hybrid system consisting of adsorption and DAF processes was introduced for the simultaneous removal of algae and taste and odor-causing organics. Powdered activated carbon (PAC) was used as an adsorbent. In this proposed system, the major concern of eliminating the spent PAC from the system was also addressed. It was found that zeta potential of algae and PAC was increased with coagulant dosage, and the removal efficiency in DAF was also enhanced up to 90~95% under the given experimental conditions. Based on this study, the hybrid process was found to be a promising technology for the simultaneous removal of algae and dissolved organic pollutants.

• 상하수도학회지
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• 제10권2호
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• pp.70-79
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• 1996

Ultrafiltration(UF) and powdered activated carbon(PAC) adsorption were combined to treat wastewater contaminated with refractory organic compounds. Secondary sewage effluent of RBC process was used for the investigation. It was determined from batch test results that a contact time of 2 hours and a PAC dose of 450mg/l would be used in the experiments. Backwashing was accomplished by forcing the permeates back ward with pressure of $2.5kgf/m^2$ for 90 seconds. It was shown that refractory organics removal by the PAC-UF process was more efficient than UF process without PAC pretreatments. As backwashing frequency was decreased from four times to one time in an hour, the removal efficiency was significantly increased. The addition of PAC to the UF process mitigated the fluctuation of filtrate quality which was increased in UF process without PAC treatment as transmembrane pressure was increased.

• 상하수도학회지
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• 제36권2호
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• pp.59-79
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• 2022

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.

• 공업화학
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• 제34권6호
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• pp.576-583
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• 2023

본 연구는 돼지 뼈 기반의 바이오매스를 가지고 새로운 흡착재의 활용가능성을 조사하였다. 이를 위하여 돼지 뼈 기반 활성탄소(pig bone based activated carbon, PAC)의 물리화학적 특성을 확인하고 이산화탄소 흡착 성능을 고찰하였다. 활성화제로 KOH를 사용하였으며, 활성화 온도가 증가할수록 비표면적이 증가하며 이산화탄소의 흡착 효율도 증가하였다. 800 ℃에서 활성화된 샘플은 1208.7 m²/g로 가장 큰 비표면적을 나타내었으며, 273 K, 1 bar에서 3.33 mmol/g로 높은 이산화탄소 흡착 효율을 보였다. 그러나 활성화 온도가 900 ℃ 이상인 조건에서는 결정성의 변화 및 과활성화로 인하여 비표면적과 이산화탄소 흡착 효율이 감소하였다. 한편 이상흡착용액이론으로 그 선택도 계산을 수행하였을 때, 273 K, 0.8 bar 이하에서 PAC-900 샘플이 가장 좋은 선택도를 보였다. 이러한 결과는 273 K에서의 이산화탄소/질소 흡착은 900 ℃에서 돼지 뼈가 활성화될 때 탄산염이 분해됨으로써 형성된 하이드록시아파타이트의 이산화탄소 흡착성과 그 결정성으로 인해 높은 선택도가 얻어진 것으로 판단된다.

• 대한토목학회논문집
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• 제6권4호
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• pp.29-42
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• 1986

산업발달로 인하여 산업공장에서 다량의 중금속이 배출되어 하천을 오염시키고 있다. 이로 인하여 수중생물에도 중금속이 축적되고, 농업용수로 이용한 농촌의 토양을 오염시키고 농작물에 중금속이 축척되는 것을 알 수 있다. 이러한 피해를 줄이기 위한 방안으로 물속에 용해되어 있는 각종 중금속을 제거시키는 것이 가장 시급한 문제이다. 따라서 본 연구에서는 폐 타이어를 이용하여 중금속중 카드뮴, 구리, 아연, 은 등의 이온을 흡착, 제거하기 위한 실험을 행했으며, 동시에 활성탄에 의한 실험을 행함으로써 폐 타이어의 효율을 비교 고찰한다. 따라서 폐기물 재활용과 공장폐수 처리장의 시설 및 운영비 절감면의 경제성에도 목적이 있다. 중금속 농도는 Automic Absorption Spectrophotometer로 측정하였으며, 온도, 흡착제주입량, 흡착제의 크기, 원수의 농도, 접촉시간 등에 따른 흡착평형식을 실험하여 흡착능을 알아내고, 또한 Column 실험을 통하여 접촉시간에 따른 중금속제거 특성과 흡착제의 여상깊이의 변화에 따른 중금속제거를 추정하여 BDST(Bed Depth/Service Time)식을 설정하여 실제 중금속 처리를 위한 설계치를 제시한다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.435-438
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• 2002

일정한 유량에 대해서 시간이 경과할수록 제거율은 약간씩 증가함을 알 수 있었으며, 이것 은 시간이 지난수록 내부세공막힘 현상이 유발되어 오염물질 자체가 제거율을 높이는 역활을 한 것으로 생각된다. 전처리한 시료에 분맞활성탄을 주입하지 않은 경우의 COD거율은 매우 낮게 나타났으며, 분말활성탄을 주입한 경우는 유기물이 분말활성탄에 흡착하여 96%의 매우 높은 제거율을 보였다. 압력에 따른 투과플럭스 및 제거율에 미치는 영향은 세가지 시료 모두 압력이 증가할수록 투과플럭스가 증가하였다. 또한 일정한 압력에 대해서 시간이 경과할수록 투과플럭스는 현저히 감소하였으며, COD 제거율은 압력이 증가할수록 약간씩 감소되었다.

• Membrane and Water Treatment
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• 제9권4호
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• pp.205-210
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• 2018

In this study, we investigated coagulants such as polyaluminum chloride (PACl) and ferric chloride ($FeCl_3$) and the combination of a coagulant and powdered activated carbon (PAC) for the removal of dissolved organic matter (DOM) from fish processing effluent to reduce membrane fouling in microfiltration. The efficiency of each pretreatment was investigated through analyses of dissolved organic carbon (DOC) and ultraviolet absorbance at 254 nm ($UVA_{254}$). Membrane flux and silt density index (SDI) analyses were performed to evaluate membrane fouling; molecular weight distributions (MWD) and fluorescence excitation-emission matrix (FEEM) spectroscopy were analyzed to assess DOM characteristics. The results demonstrated that $FeCl_3$ exhibited higher DOC and $UVA_{254}$ removals than PACl for food processing effluent and a combination of $FeCl_3$ and PAC provided comparatively better results than simple $FeCl_3$ coagulation for the removal of DOM from fish processing effluent. This study suggests that membrane fouling could be minimized by proper pretreatment of food processing effluent using a combination of coagulation ($FeCl_3$) and adsorption (PAC). Analyses of MWD and FEEM revealed that the combination of $FeCl_3$ and PAC was more efficient at removing hydrophobic and small-sized DOM.

• 대한토목학회논문집
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• 제37권2호
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• pp.475-483
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• 2017

녹조현상 발생시 남조류에 의하여 발생하는 이취미 물질인 Geosmin과 2-methylisoborneol(2-MIB)는 수돗물에 냄새를 유발하는 원인 물질로서 제거가 필요하다. 일반적으로 정수장에서는 이취미 물질의 제거를 위하여 활성탄을 사용하고 있으나 활성탄의 기공 분포와 활성탄의 입자크기가 이취미 물질 흡착제 미치는 영향에 대한 정보는 부족하다. 따라서, 본 연구에서는 다양한 활성탄의 기공분포와 활성탄의 입자 크기가 이 취미 물질 흡착에 미치는 영향을 살펴보았다. 분말활성탄(PAC), 입상활성탄(GAC), 활성탄소섬유(ACF)의 이취미 물질 흡착을 비교한 결과, PAC > ACF > GAC 순서로 이취미물질 흡착제거효율이 높았다. 다양한 기공분포 특성을 갖는 분말활성탄들을 비교한 결과, 미세기공이 잘발달된 경우가 Geosmin과 2-MIB의 흡착에 유리한 것으로 나타났으며, 입자 크기의 경우에는 작을수록 Geosmin과 2-MIB의 흡착에 보다 효과적이었다.

• 상하수도학회지
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• 제24권1호
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• pp.15-24
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• 2010

Coagulation can be used for pretreatment of NF membrane filtration. Foulants such as organic matter and particulate can be removed effectively with the process while high flux recovery is maintained. Recently various types of polyaluminium coagulants including polyaluminium chloride(PAC) are commercially available for water treatment. This study examines effects of polymeric Al and hydrolysis products of PAC on nanofiltration membrane performance. Dominant hydrolysis products were polymeric Al, $Al(OH)_3$, and ${Al(OH)_4}^{-1}$ at acidic, neutral, and alkaline pH conditions, respectively. Under acidic pH condition, flux decline was increased with increasing PAC concentrations, possibly due to polymeric Al adsorption on membrane pore and/or surfaces. For neutral and alkaline pH conditions, little flux decline was observed with increasing PAC concentrations except the highest ${Al(OH)_4}^{-1}$ concentration, with which rapid flux decline was shown. Removal of ionic matters was also varied with pH conditions in this study. Especially, conductivity removal was substantially low and $Ca^{2+}$ concentration in the permeate was quite high at neutral pH condition.