• Journal of Korean Society of Environmental Engineers
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• v.29 no.4
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• pp.404-411
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• 2007

Adsorption performance of odorous compounds such as geosmin and 2-MIB on granular activated carbon were evaluated in this study. The coal-based activated carbon was found more effective than other carbons in adsorption of geosmin and 2-MIB. The wood-based virgin activated carbon was less effective than coconut- and coal-based carbon in adsorption nevertheless having larger pore volume and specific surface area than others carbons. The maximum adsorption capacity(X/M) of coal-based activated carbon for geosmin and 2-MIB was $1.2\sim1.9$ and $2.1\sim2.6$ times larger than coconut- and wood-based virgin activated carbon, respectively. Carbon usage rate (CUR) of coal-, coconut- and wood-based virgin activated carbons for geosmin and 2-MIB were 1.72 and 1.44 g/day, 1.72 and 2.05 g/day and 2.12 and 1.90 g/day, respectively. In the evaluation of adsorption isotherm of geosmin and 2-MIB for coal-, coconut- and wood-based virgin activated carbons, k value of 2-MIB was lower than geosmin, It menas 2-MIB is more difficult to remove by activated carbon adsorption than geosmin. The relationship of max. adsorption versus total pore volume of coconut- and wood-based virgin and used activated carbon for geosmin and 2-MIB were $y=264,459\times-79,047(R^2=0.95)$, $y=319,650\times-101,762(R^2=0.93)$.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.9
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• pp.747-752
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• 2009

This research was performed by means of several different virgin granular activated carbons (GAC) made of each coal, coconut and wood, and the GACs were investigated for an adsorption performance of bromate in a continuous adsorption column. Breakthrough behavior was investigated that the breakthrough points of the virgin two coals-, coconut- and wood-based GACs were observed as 9252 bed volume (BV), 6821 BV, 5291 BV and 2431 BV, respectively. The experimental results of adsorption capacity (X/M) for bromate showed that two coal- based GACs were highest (1334.5 and 798.2 ${\mu}g$/g), the coconut-based GAC was intermediate (668.6 ${\mu}g$/g) and the wood-based GAC was lowest (156.8 ${\mu}g$/g). The X/M of the coal-based GACs was 2~8.5 times higher than the X/M of the coconut-based and wood-based GACs. The results of carbon usage rates (CURs) for the virgin two coal-, coconut- and wood-based GACs were shown as 0.19, 0.25, 0.33 and 0.71 g/day respectively. The adsorption capacity, k values, were also investigated by means of the GACs for bromate. The k values of two coal-, coconut- and wood- based GACs for bromate were found to be 121.3, 76.7, 43.3 and 14.6 respectively. This results suggested that using the virgin GAC made of coal was the best selection for removal of bromate in the water treatment for an advanced treatment.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.4
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• pp.401-408
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• 2008

Adsorption performance of sulfonamide antibiotic compounds such as sulfadimethoxine(SDM), sulfachloropyridazine(SCP), sulfamethazine(SMT), sulfathiazole(STZ) and sulfamethoxazole(SMX) on granular activated carbon(GAC) was evaluated in this study. The coal-based activated carbon was found to be more effective than other carbons in adsorption of sulfonamide antibiotic compounds. The wood-based activated carbon was less effective than coconut- and coal-based carbon in adsorption nevertheless having larger pore volume and specific surface area than others carbons. The maximum adsorption capacities(X/M) of coal-based activated carbon for the five sulfonamide species was 1.3$\sim$1.5 and 1.8$\sim$2.1 times larger than coconut- and wood-based activated carbon, respectively. Carbon usage rates (CUR) of coal-, coconut- and wood-based activated carbons for SCP were 3.55 g/day, 4.29 g/day and 6.47 g/day, respectively. Similar results were obtained in the adsorption of the rest four sulfonamide species. It is concluded that coal-based activated carbon could removed the sulfonamide antibiotic compounds better than other material-based activated carbons.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.9
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• pp.925-932
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• 2008

Adsorption performance of tetracycline antibiotic compounds such as tetracycline(TC), oxytetracycline(OTC), chlortetracycline (CTC) and minocycline(MNC) on granular activated carbon(GAC) was evaluated in this study. The coal-based activated carbon was found to be more effective than other carbons in adsorption of tetracycline antibiotic compounds. The wood-based activated carbon was less effective than coconut- and coal-based carbon in adsorption nevertheless having larger pore volume and specific surface area than others carbons. The maximum adsorption capacities(X/M) of coal-based activated carbon for the four tetracycline species was 1.27$\sim$1.36 and 1.69$\sim$1.84 times larger than coconut- and wood-based activated carbon, respectively. Carbon usage rates(CUR) of coal-, coconut- and wood-based activated carbons for tetracycline(TC) were 2.96 g/day, 3.40 g/day and 4.53 g/day, respectively. Similar results were obtained in the adsorption of the rest three tetracycline species. It is concluded that coal-based activated carbon could removed the tetracycline antibiotic compounds better than other material-based activated carbons.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1311-1320
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• 2005

The purpose of this research is to survey characteristics of microbial community and the removal efficiency of organic materials for biological activated carbon in water treatment plant. Coal based activated carbon retained more attached bacterial biomass on the surface of the activated carbon than the other activated carbon with operating time and materials. The heterotrophic plate count(HPC), eubacteria(EUB) and 4,6-diamidino-2-phenylindole(DAPI) counts were ranged from $0.95{\times}10^7$ to $52.4{\times}10^7$ CFU/g, from $3.8{\times}10^8$ to $134.2{\times}10^8$ cells/g and from $7.0{\times}10^8$ to $250.2{\times}10^8$ cells/g, respectively. The biomass of EUB and DAPI appeared to be much more $10^2$ than HPC, which were increasing in bed volume of 20,000 at the stage of steady-state. The change of microbial community by analyzing fluorescent in situ hybridization(FISH) method with rRNA-targeted oligonucleotide probes, the dominant group was $\alpha$-proteobacteria($\alpha$ group) and high G+C content bacteria(HGC) the lowest distributing rate before reaching the bed volume of 20,000. After reaching the bed volume of 20,000, $\alpha$ group and other groups of bacteria became decreased, on the other hand, the proportion of both $\beta$-proteobacteria($\beta$ group) and $\gamma$-proteobacteri($\gamma$ group) were increasing. Coconut and wood based activated carbons had similar trend with coal based activated carbon, but the rate of $\alpha$ group on coal based activated carbon had gradually increased. Bacterial production with the operating period appeared highest in coal based activated carbon at the range of $1.2{\sim}3.4\;mg-C/m^3{\cdot}h$ while the coconut and wood based activated carbon were ranged from 1.1 to 2.6 $mg-C/m^3{\cdot}h$ and from 0.7 to 3.5 $mg-C/m^3{\cdot}h$ respectively. The removal efficiency of assimilable organic carbon(AOC) showed to be highly correlated with bacterial production. The correlation coefficient between removal efficiency of AOC and bacterial production were 0.679 at wood based activated carbon, 0.291 at coconut based activated carbon and 0.762 at coal based activated carbon, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.4
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• pp.438-443
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• 2007

This study was done to investigate perchlorate contamination in Nakdong river. The perchlorate was detected in Nakdong river and ranged from ND to $82.1{\mu}g/L$. The highest concentration was observed in Wheguan. The perchlorate concentration was decreased with the down stream of Nakdong river. Three different virgin activated carbons made of each coal(Calgon), coconut(Samchully) and wood(Picabiol) based activated carbon(AC) were tested for an adsorption performance of perchlorate in a continuous adsorption column. Breakthrough behavior was investigated that the breakthrough points of coal, coconut and wood based AC as 2,300 bed volumn(BV), 719 BV and 288 BV respectively. Adsorption capacity(X/M) of real, coconut and wood based AC was observed. The experimental results of adsorption capacity showed that coal based AC was highest$(768.2{\mu}g/g)$, coconut based AC was intermediate$(299{\mu}g/g)$ and wood based AC was lowest$(99.2{\mu}g/g)$. Moreover, carbon usage rates(CURs) for coal, coconut and wood based AC had been shown as 0.71 g/day, 2.16 g/day and 3.45 g/day respectively. The constant characteristic of the system, k of coal, coconut and wood based ACs were found to be 307.2, 102.5 and 94.2, respectively.

• 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.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.2
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• pp.218-224
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• 2008

Coal-, coconut- and wood-based activated carbons and anthracite were tested to evaluate adsorption and biodegradation performances of chloral hydrate. In the early stage of the operation, the adsorption was the main mechanism for the removal of chloral hydrate, however as increasing populations of attached bacteria, the bacteria played a major role in removing chloral hydrate in the activated carbon and anthracite biofilter. It was also investigated that chloral hydrate was readily subjected to biodegrade. The coal- and coconut-based activated carbons were found to be most effective adsorbents in adsorption of chloral hydrate. Highest populations and activity of attached bacteria were shown in the coal-based activated carbon. The populations and activity of attached bacteria decreased in the order: coconut-based activated carbon > wood-based activated carbon > anthracite. The attached bacteria was inhibited in the removal of chloral hydrate at temperatures below 10$^{\circ}C$. It was more active at higher water temperatures(20$^{\circ}C$ <) but less active at lower water temperature(10$^{\circ}C$>). The removal efficiencies of chloral hydrate obtained by using four different adsorbents were directly related to the water temperatures. Water temperature was the most important factor for removal of chloral hydrate in the anthracite biofilter because the removal of chloral hydrate depended mainly on biodegradation. Therefore, the main removal mechanism of chloral hydrate by applying activated carbon was both adsorption and biodegradation by the attached bacteria. The observation suggests that the application of coalbased activated carbon to the water treatment should be the best for the removal of chloral hydrate.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.762-770
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• 2005

Adsorption and biodegradation performance of chlorinated by-products such as trihalomethanes(THMs) and haloacetic acids(HAA5) on granular activated carbon were evaluated in this study. The coconut-based activated carbon was found more effective than others in adsorption of THMs due to larger pore volume of less than $20{\AA}$. The wood-based activated carbon was less effective than coconut- and coal-based activated carbon in adsorption nevertheless having larger pore volume and specific surface area than others. The maximum adsorption capacity(X/M) of coconut-based carbon for THMS was 1.1-1.5 times larger than coal based carbon and 14.1-31.4 times larger than wood based activated carbons. Activated carbon usage rate(CUR) of coconut-, coal- and wood-based activated carbons for chloroform were 9.4, 11.2 and 38 g/day respectively. In the evaluation of adsorption isotherm of THM species for coconut-, coal- and wood-based activated carbons, k value of chloroform was the lowest in the THM species, It menas that chloroform is difficult to remove by activated carbon adsorption. and BDCM, CDBM, bromoform are in the succeeding order of adsorption. In the evaluation of biodegradation rate, mean biodegradation rate was chloroform 7%, BDCM 5%, CDBM 4% and bromoform 3%, respectively THMs are difficult materials to be biodegraded. In the evaluation of characteristics of adsorption and biodegradation for HAA5 species, HAA5 species appear to be removed effectively by activated carbon. Most of the HAA5 are adsorbed at the beginning of operation periods and HAA5 except TCAA were almost biodegraded from bed volume of 2,000 and more than 90 percent of biodegradation of TCAA was started from bed volume around 4,000 and after that biodegradation rate was increased with increasing bed volume.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.2
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• pp.184-191
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• 2007

Coal-, coconut- and wood-based activated carbons and anthracite were tested for an adsorption and biodegradation performances of nitrogenous chlorinated by-products such as chloropicrin, DCAN, DBAN and TCAN. In early stage of operations, an adsorption performance was a main mechanism for removal of nitrogenous chlorinated by-products, however as increasing populations of attached bacteria, the bacteria played a major role in removing nitrogenous chlorinated by-products in the activated carbon and anthracite biofilter. It was also investigated that the compounds were readily subjected to biodegrade. Whilst the coal- and coconut-based activated carbons were found most effective in adsorption of the compounds, the anthracite was worst in adsorption of the compounds. Highest populations and activity of attached bacteria were shown in the coal-based activated carbon. The populations and activity of attached bacteria decreased in the order: coconut-based activated carbon > wood-based activated carbon > anthracite. The attached bacteria were inhibited for removal of the compounds at temperatures below $10^{\circ}C$. The attached bacteria were more active at higher water temperatures$(20^{\circ}C\;<)$ but less active at love. water temperature$(10^{\circ}C\;>)$. The removal efficiencies of the compounds obtained using coal-, coconut- and wood-based activated carbons and anthracite were directly related to the water temperatures. In particular, water temperature was the most important factor for removal of the compounds in the anthracite biofilter because the removal of the compounds depended mainly on biodegradation. Therefore, the main removal mechanism of the compounds the main mechanism on the removal of the compounds using activated carbon was both adsorption and biodegradation by the attached bacteria. The observation suggests that using coal-based activated carbon is the best for removal of nitrogenous chlorinated by-products in the water treatment.