• Journal of Korean Society of Environmental Engineers
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• v.37 no.7
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• pp.404-411
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• 2015

In this study, the effects of empty bed contact time (EBCT) and water temperature on the biodegradation of 9 halonitromethanes (HNMs) in biological activated carbon (BAC) process were investigated. Experiments were conducted at three water temperatures ($10^{\circ}C$, $15^{\circ}C$ and $25^{\circ}C$) and three EBCTs (5, 10 and 15 min). Increasing EBCT and water temperature increased the biodegradation efficiency of HNMs in BAC column. Dibromochloronitromethane (DBCNM) and tribromonitromethane (TBNM) showed the highest biodegradation efficiency, but chloronitromethane (CNM) and dichloronitromethane (DCNM) were the lowest. The kinetic analysis suggested a pseudo-first-order reaction model for biodegradation of 7 HNMs at various water temperatures and EBCTs. The pseudo-first-order biodegradation rate constants ($k_{bio}$) of 7 HNMs ranged from $0.0797{\sim}0.7657min^{-1}$ at $10^{\circ}C$ to $0.1245{\sim}1.8421min^{-1}$ at $25^{\circ}C$. By increasing the water temperature from $10^{\circ}C$ to $25^{\circ}C$, the biodegradation rate constants ($k_{bio}$) were increased 1.6~2.4 times.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.12
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• pp.858-864
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• 2014

In this study, The effects of empty bed contact time (EBCT) and water temperature on the biodegradation of 8 synthetic fragrances (SFs) in biological activated carbon (BAC) process were investigated. Experiments were conducted at two water temperatures (7 and $18^{\circ}C$) and three EBCTs (5, 10 and 15 min). Increasing EBCT and water temperature increased the biodegradation efficiency of SFs in BAC column. Pentalide and ambrettolide were the highest biodegradation efficiency, but DPMI and ADBI were the lowest. The kinetic analysis suggested a pseudo-first-order reaction model for biodegradation of 8 SFs at various water temperatures and EBCTs. The pseudo-first-order biodegradation rate constants ($k_{bio}$) of 8 SFs ranging from $0.1184{\sim}0.6545min^{-1}$ at $7^{\circ}C$ to $0.3087{\sim}0.9173min^{-1}$ at $18^{\circ}C$. By increasing the water temperature from $7^{\circ}C$ to $18^{\circ}C$, the biodegradation rate constants ($k_{bio}$) were increased 1.4~2.6 times.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.11
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• pp.739-746
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• 2014

In this study, The effects of empty bed contact time (EBCT) and water temperature on the biodegradation of 8 UV filters in biological activated carbon (BAC) process were investigated. Experiments were conducted at two water temperatures (7 and $18^{\circ}C$) and three EBCTs (5, 10 and 15 min). Increasing EBCT and water temperature increased the biodegradation efficiency of UV filters in BAC column. EHMC and BZC were the highest biodegradation efficiency, but BP and 4-MBC were the lowest. The kinetic analysis suggested a first-order reaction model for biodegradation of 8 UV filters at various water temperatures and EBCTs. The first-order biodegradation rate constants ($k_{bio}$) of 8 UV filters ranging from $0.2730{\sim}0.6365min^{-1}$ at $7^{\circ}C$ to $0.4824{\sim}0.8743min^{-1}$ at $18^{\circ}C$. By increasing the water temperature from $7^{\circ}C$ to $18^{\circ}C$, the biodegradation rate constants ($k_{bio}$) were increased 1.5~2.1 times.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.12
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• pp.1255-1261
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• 2008

In this study, The effects of three different biological activated carbon (BAC) materials (each coal, coconut and wood based activated carbons), empty bed contact time (EBCT) and water temperature on the removal of haloacetic acid (HAA) 5 species in BAC filters were investigated. Experiments were conducted at three water temperatures (5, 10 and 20$^{\circ}C$) and four EBCTs (5, 10, 15 and 20 min). The results indicated that coal based BAC retained more attached bacterial biomass on the surface of the activated carbon than the other BAC, increasing EBCT or increasing water temperature increased the HAA 5 species removal in BAC columns. To achieve an HAA removal efficiency 50% or higher in a BAC filter, the authors suggest 10 min EBCT or longer for 5$^{\circ}C$ waters and 5 min EBCT for waters at 10$^{\circ}C$ or higher. The kinetic analysis suggested a first-order reaction model for HAA 5 species removal at various water temperatures (5, 10 and 20$^{\circ}C$). The pseudo-first-order reaction rate constants and half-lives were also calculated for HAA removal at 5, 10 and 20$^{\circ}C$. The pseudo-first-order reaction rate constants and half-lives were also calculated for HAA 5 species removal at 5$\sim$ 20$^{\circ}C$. The half-lives of HAA 5 species ranging from 0.75 to 18.58 min could be used to assist water utilities in designing and operating BAC filters for HAA removal.

• 수도
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• v.23 no.6 s.81
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• pp.30-35
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• 1996

조류의 성장에 기인하여 대청호로부터 발생된 이취미와 천연유기물질의 제거를 위해 활성탄 흡착에 관한 파일롯 플랜트연구를 수행하였다. 대청호원수의 용존유기물질 농도는 1.5-3.5mg/1으로 나타났고, 이취미를 유발시킨 주 성분인 Geosmin농도는 가을에 60ng/1 이상이 검출되었다. 이는 8월말부터 발생하기 시작하여 10월말 까지 지속되었다. 이는 8월말부터 발생하기 시작하여 10월말 까지 지속되었다. 한국수자원공사 대청수도내 파일롯 플랜트는 재래식정수처리 시스템에 오존산화공정, 4개의 입상활성탄 흡착탑으로 구성되었다. 공탑체류시간(EBCT) 15분 이상에서, 이취미 발생기간동안 GAC 3지와 4지에서 이취미는 완전히 제거되었다. 활성탄 원료 종류별 DOC제거를 위한 파일롯연구에서 석탄계 활성탄으로 충진한 GAC 3지와 4지는 운전 3개월 후에 파괴되기 시작하였고, 이 후 4개월의 운전동안 약 40-50%의 일정한 제거효율을 보여주었다. 야자계 활성탄으로 충진된 GAC 2지는 2개월의 운전 후에 완전히 파괴되었다.

• Korean Journal of Environmental Agriculture
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• v.21 no.3
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• pp.208-215
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• 2002

This study was carried out to evaluate the pollutant removal efficiencies of the advanced drinking water treatment using activated carbon process. for raw water, Nakdong river was used. from the activated carbon adsorption experiment the fellowing results were obtained The efficiency of water treatment enhanced with increase in empty bed contact time. Variation of pH was not detected to the bed depth, but DO content gradually decreased with the bed depth. Removal efficiency of $KMnO_4$ consumption, UV254 absorption, DOC and THMFP also were increased by increasing in the bed depth. Transition of adsorption zone from upper parts of the bed to the lower parts were detected as treatment periods increased. Large portion of DOCs were degraded and removed by the microbes growing on the surface of activated carbons. Cell numbers of microbes were estimated over $1.1\times10^7\;cell/cm^3$ at the depth of 20 cm from the surface 126 days after starting operation. The results shown that the activated carbon Inter was successfully acted as a biofilm filter.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.6
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• pp.677-686
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• 2006

This study was the effectiveness of two downflow BAF(Biological Aerated Filter) systems at conventional water treatment system. A BAF reactor placed in front of coagulation and sedimentation tanks(Mode A) and after coagulation and sedimentation tanks(Mode B) that were compared in terms of removal of suspended particles, organic matters, and ammonia nitrogen. The suspended particles removal efficiency was over 80% for both Mode A and B, although Mode A gave slightly better results. $BOD_5$ removal and nitrification efficiencies were more than 90% for both reactor. The organic matter and ammonia removals were also superior in the Mode A. The biofilm thickness and biomass increased as increment of EBCT and the upper part of reactor more about 30% than lower part. The specific oxygen uptake rate(SOUR) was higher the upper part of reactor and Mode A than the lower part of reactor and Mode B. A cost analysis showed that the Mode A system was more cost effectiveness. It could save the coagulant dose by about 67% and the chlorine demand by about 95%. The ideal place to put the BAF reactor was in front of the coagulation/sedimentation process.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1192-1197
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• 2006

Adsorbability of ionic and nonionic pharmaceuticals was studied using granular activated carbon(GAC). In a batch adsorption test of muticomponent solution, 500 mg/L of GAC dose removed all target compounds between 94 and 98% at initial concentration of 10 ${\mu}g/L$. Adsorption of ionic pharmaceuticals increased as pH was lowered toward to pKa, however adsorption capacity of nonionic pharmaceuticals showed insignificant variation with the changing pH. The enhanced adsorption capacity of ionic pharmaceuticals at lower pH was attributed to the corresponding increase in the molecular form of ionic pharmaceuticals with carboxylic group at low pH. In addition, decrease of pH increased hydrogen ion concentration in the bulk solution and the protons bound to the available sites on the carbon enhanced the removal of the ionic pharmaceuticals from solution. After 40 days of continuous operation, GAC column showed the removal of target compounds were removed by $93{\sim}99%$ at 15 min of EBCT mainly due to adsorption mechanism of GAC. At shorter EBCT than 15 min, breakthrough of CA, IBP and GFZ occurred earlier than the other ionic and nonionic pharmaceuticals. effect of EBCT on adsorption of nonionic pharmaceuticals was greater than ionic ones. This study showed that persitent pharmaceuticals found in drinking water treatment could be effectively controlled by adsorption in GAC process.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.3
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• pp.195-203
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• 2012

In this study, The effects of three different biological activated carbon (BAC) materials (each coal, coconut and wood based activated carbons) and anthracite, empty bed contact time (EBCT) and water temperature on the removal of MK, HHCB and AHTN in BAC filters were investigated. Experiments were conducted at three water temperatures (5, 15 and $25^{\circ}C$) and four EBCTs (5, 10, 15 and 20 min). The results indicated that coal based BAC retained more attached bacterial biomass on the surface of the activated carbon than the other BAC, increasing EBCT or increasing water temperature increased the synthetic musk compounds (SMCs) removal in BAC columns. The kinetic analysis suggested a first-order reaction model for MK, HHCB and AHTN removal at various water temperatures (5, 15 and $25^{\circ}C$). The pseudo-first-order biodegradation rate constants and half-lives were also calculated for MK, HHCB and AHTN removal at 5, 15 and $25^{\circ}C$. The pseudo-first-order biodegradation rate constants and half-lives of MK, HHCB and AHTN ranging from 0.0082 $min^{-1}$ to 0.4452 $min^{-1}$ and from 1.56 min to 84.51 min could be used to assist water utilities in designing and operating BAC filters for SMCs removal.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.3
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• pp.186-192
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• 2009

In this study, The effects of three different activated carbon materials (each coal, coconut and wood based activated carbons), empty bed contact time (EBCT) and water temperature on the removal of pharmaceutical 4 species (oxytetracycline, tetracycline, trimethoprime and caffeine) in BAC filters were investigated. Experiments were conducted at three water temperature (5, 15 and $25^{\circ}C$) and four EBCTs (5, 10, 15 and 20 min). The results indicated that coal based BAC retained more attached bacterial biomass on the surface of the activated carbon than the other BAC, increasing EBCT or increasing water temperature increased the pharmaceutical 4 species removal in BAC columns. In the coal-based BAC columns, removal efficiencies of oxytetracycline and tetracycline were 87~100% and removal efficiencies of trimethoprime and caffeine were 72~99% for EBCT 5~20 min at $25^{\circ}C$. The kinetic analysis suggested a firstorder reaction model for pharmaceutical 4 species removal at various water temperatures (5~$25^{\circ}C$). The pseudo-first-order reaction rate constants and half-lives were also calculated for pharmaceutical 4 species removal at 5~$25^{\circ}C$. The reaction rate and half-lives of pharmaceutical 4 species ranging from 0.0360~0.3954 $min^{-1}$ and 1.75 to 19.25 min various water temperatures and EBCTs, could be used to assist water utilities in designing and operating BAC filters.