• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1037-1044
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• 2000

The objective of this study is the preparation of activated carbon for BAC(biological activated carbon). Prepared activated carbon was measured iodine adsorption(mg/g). methylene blue adsorption(mg/g), B.E.T($m^2/g$), PSD(Pore Size Distribution) and 'Picabiol' which in commercial activated carbon for BAC. Activation method for this study was a chemical activation used the phosphoric acid. In the method, two important factors affected activation characterized in preparation were temperature and impregnated phosphoric acid concentration. Activation temperature and impregnated phosphoric acid concentration were changed the $600{\sim}800^{\circ}C$ and 35~50wt% respectively. Activation time was fixed for 3 hour. Optimal activation temperature was $800^{\circ}C$ and impregnated phosphoric acid concentrations was about 50wt%. By the above condition specific surface area, iodine adsorption number and methylene blue adsorption number resulted $1643.3m^2/g$, 1093 mg/g, 445.6 mg/g, respectively.

• Environmental Engineering Research
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• v.19 no.4
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• pp.309-316
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• 2014

The water quality improvement of golf course ponds, as representative stagnant stream channels, was evaluated by applying a biological activated carbon (BAC) process composed of four consecutive activated carbon reactors. The study was performed from autumn to winter in order to evaluate the feasibility of the BAC process under low temperature conditions. In the study, water quality of pond A (target pond) and pond B (reference pond) were monitored. Pond water was pumped into the BAC process, and was then returned to the pond after treatment. The optimal conditions were determined to be 2 hr of empty bed contact time (EBCT) at a temperature above $4^{\circ}C$, in which improvements of chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) of pond A compared to pond B were 3.62%, 3.48% and 1.81%, respectively. On the other hand, as the temperature was below $4^{\circ}C$, some degree of water quality improvement was achieved even when EBCT were 1 or 0.5 hr, suggesting that the BAC process can be successfully applied for the improvement of pond water quality in winter months. The values of biomass concentration and microorganism activity in each condition were highest where 2 hr of EBCT was applied at a temperature above $4^{\circ}C$, but values were similar throughout all treatment conditions, and thus, adsorption is considered to be the dominant factor affecting process efficiency. From the denaturing gel gradient electrophoresis (DGGE) results, no significant differences were observed among the activated carbon reactors, suggesting that the number of reactors in the system could be decreased for a more compact application of the system.

• 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 Water and Wastewater
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• v.23 no.2
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• pp.189-198
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• 2009

Tastes and odor in water caused by geosmin and 2-MIB are the major customer complaints for water utilities. Therefore, control of geosmin and 2-MIB is a worldwide concern. In this study, the effects of biofilter media type (three different activated carbons and anthracite), empty bed contact time (EBCT) and temperature on the removal of geosmin and 2-MIB in BAC filters were investigated. Experiments were conducted at three different water temperatures (5, 15 and $25^{\circ}C$) and four different EBCTs (5, 10, 15, and 20 min). The experimental results indicated that the coal based BAC retained more bacterial biomass on the surface of the activated carbon than the other BACs, and increasing EBCT or increasing water temperature also increased the geosmin and 2-MIB removal in BAC filters. To achieve above 50% of removal efficiency for geosmin and 2-MIB in a BAC filter, above 10 min EBCT at $5^{\circ}C$ and 5 min EBCT at above $15^{\circ}C$ were required. The kinetic analysis for the biodegradation of geosmin and 2-MIB indicated a first-order reaction rate at various water temperatures. Data obtained from the BAC filters at various temperatures were also used to evaluate pseudo first-order rate constants for geosmin and 2-MIB. The half-lives evaluated at 5, 15, and $25^{\circ}C$ for geosmin and 2-MIB ranged from 2.39 to 10.31 min and 3.35 to 13.97 min, respectively, which can be used to assist water utilities in designing and operating BAC system.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.1
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• pp.47-55
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• 2015

Recently, the production of taste and odor (T&O) compounds is a common problem in water industry. Geosmin is one of the T&O components in drinking water. However, geosmin is hardly eliminated through the conventional water treatment systems. Among various advanced processes capable of removing geosmin, adsorption process using granular activated carbon (GAC) is the most commonly used process. As time passes, however GAC process changes into biological activated carbon (BAC) process. There is little information on the BAC process in the literature. In this study, we isolated and identified microorganisms existing within various BAC processes. The microbial concentrations of BAC processes examined were $3.5{\times}10^5$ colony forming units (CFU/g), $2.2{\times}10^6CFU/g$ and $7.0{\times}10^5CFU/g$ in the Seongnam plant, Goyang plant and Goryeong pilot plant, respectively. The dominant bacterial species were found to be Bradyrhizobium japonicum, Novosphingobium rosa and Afipia broomeae in each plants. Removal efficiencies of $3{\mu}g/L$ geosmin by the dominant species were 36.1%, 36.5% and 34.3% in mineral salts medium(MSM) where geosmin was a sole carbon source.

• Journal of Environmental Health Sciences
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• v.32 no.1 s.88
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• pp.71-76
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• 2006

Treatment performance and microbial community structure were investigated in water-soluble cutting oil treatment process using biological activated carbon. DOC removal in BACI column at $15^{\circ}C$ was higher than at $25^{\circ}C$, but those of BAC3 column after 60days was high at$25^{\circ}C$. Also, quinone content of first-step reactors at $25^{\circ}C$ and $15^{\circ}C$ was much the same, but those of the third-step reactor at $25^{\circ}C$ was higher than at $15^{\circ}C$. The dominant type of two apparatus was ubquinone (UQ)-l 0 followed by UQ-8. Menaquinones were detected from $25^{\circ}C$ apparatus and effluent. This suggested that DOC removal at $25^{\circ}C$ was advanced degradation by attached microorganisms on the activated carbon surface. The DOC removal in long-term activated carbon apparatus increased with going in BAC3 column. This indicated the influent of POC was a result of DOC removal efficiency decrease. Integrated DOC removal from start point in experiment to break point and quinone content were showed a tendency of increasing with going last-step activated carbon apparatus. Therefore, the biological activated carbon apparatus used by this study was effective treatment process in contaminated groundwater by water-soluble cutting oil.

• Journal of Environmental Science International
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• v.24 no.12
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• pp.1551-1558
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• 2015

In Korea, many drinking water treatment plants (DWTPs) have introduced and are going to introduce biological activated carbon (BAC) process to treated dissolved organic matter (DOM) in water which are difficult to control by conventional water treatment processes. Even though more decade have passed since introduced BAC in Korea, most of BAC operating method was followed to the modified sand filter operating manuals. In case of BAC backwashing, many DWTPs set the periods of backwashing about 3~5 days. In this study, we have collected data to set the proper BAC backwashing periods from both pilot-plant and real DWTPs. We had measured heterotrophic plate count (HPC), turbidity, water temperature, dissolved organic carbon (DOC) and headloss from just after backwashing to the next backwashing time for two years. Considering water quality factors, the BAC run time from backwashing to the next backwashing could extend more 30 days without water quality deterioration if the head loss do not reach the limited level which depends on each BAC facilities' condition. It means the BAC treated water could be saved in the proportion of extended the backwashing period to the existing backwashing period.

• Journal of Wetlands Research
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• v.17 no.2
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• pp.155-162
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• 2015

This study was conducted to assess the removal characteristics of taste and odor causing compounds(2-MIB and geosmin) and micro organic matters. GAC and BAC process consisting of Ozone/AOP and activated carbon was applied. As a result, the influent concentration of 2-MIB 159 ng/L and geosmin 371 ng/L were removed 42% and 86% by ozone 1.0 mg/L, and 58%, 90% by AOP(ozone 1.0 mg/L + $H_2O_2$ 0.5 mg/L). Also it showed less than 2 ng/L effluent in GAC process and 99.8% removal efficiency in BAC process. Therefore, BAC process combining ozone/AOP and GAC is effective for persistent removal of micro organic matters, taste and odor. It is needed for optimization of Ozone/AOP process according to influent concentrations.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.8
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• pp.533-540
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• 2012

The concentration of organic compounds was analyzed at each step of BAC (biological activated carbon) process though BDOC (biodegradable dissolved organic carbon) total/rapid/slow. Further, bacteria communities and biomass concentrations measured DGGE (denaturing gradirnt gel electrophoresis) and ATP (adenosine triphosphate) methods were analyzed. The bed volume of steady state is different based on assessment of organic compounds removal. Bed volumes at steady state in DOC, $BDOC_{rapid}$ and $BDOC_{total/slow}$ removal were around 27,500, 15,000 and 32,000, respectively. A biomass didn't change after the bed volume reached 22,500 according to analyzing HPC (heterotrophic plate count) and ATP concentration of bacteria. The concentration of HPC and ATP were $3.3{\times}10^8$ cells/g and $2.14{\mu}g/g$, respectively. The number of the DGGE band were only 5 at the bed volume 8,916, but increased up to 11 at the bed volume 49,632. As operation time increase, bacterial group were more diversity. Four bacteria species including Pseudomonas fluorescens, the uncultured bacterium similar to Acinetobacteria, uncultured Novosphingobium sp. and Flavobacterium frigidarium have detected from the early stages and Proteobacteria group were dominantly detected.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.11
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• pp.989-996
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• 2009

In this study, the effects of biofilter media type (three different activated carbons and anthracite), empty bed contact time (EBCT) and temperature on the removal of four aldehyde species (formaldehyde, acetaldehyde, glyoxal and methylglyoxal) 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 experimental results indicated that the coal based BAC retained more bacterial biomass on the surface of the activated carbon than the other BACs, and increasing EBCT or increasing water temperature also increased the four aldehyde species removal in BAC filters. To achieve above 80% of removal efficiency for four aldehyde species in a BAC filter, above 15 min EBCT at $5^{\circ}C$ and 10 min EBCT at above $15^{\circ}C$ were required. The kinetic analysis indicated a first-order reaction rate for the biodegradation of four aldehyde species at various water temperatures. Data obtained from the BAC filters at various temperatures were also used to evaluate pseudo first-order rate constants for four aldehyde species. The half-lives evaluated for formaldehyde, acetaldehyde, glyoxal and methylglyoxal in the coal-based BAC ranging from 0.89 to 3.19 min, from 0.75 to 3.35 min, from 2.16 to 4.72 min and from 1.49 to 3.86 min, respectively, could be used to assist water utilities in designing and operating BAC filters.