• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.601-608
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• 2008

The objective of this study was to evaluate the effect of ozonation as pretreatment on the removal of dissolved or biodegradable organic matter(DOM or BOM), the variance of DOM fractionation, and microbial regrowth by pilot-scale granular activated carbon processes in which adsorption and biodegradability was proceeding due to long time operation. Regardless of point of ozonation applied, GAC processes with ozonation(i.e., Ozonation combined with GAC Filter-adsorber; Pre O$_3$ + F/A, Ozonation combined with GAC adsorber; Post O$_3$ + GAC) compared with GAC processes without ozonation(i.e., GAC Filter-adsorber; F/A, GAC adsorber; GAC) removed approximately 10 to 20% more of DOC, hydrophilic DOM(HPI), BDOC and AOC after long period of operation that biological activity was assumed to happen. Ozonation was not found to have a significant effect on the removal of DOC, but caused the decrease of AOC by approximately 20%. It was found that the fixed bacterial biomass on GAC media did not show a significant difference between the GAC with ozonation and GAC without ozonation as pre-treatment, whereas the HPC of column effluent was more biostable at Post O$_3$ + GAC compared with F/A or GAC.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.09a
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• pp.5-38
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• 1996

최근에 산업발전, 유독물의 사용 증가에 따라 이들이 하천, 호소 및 지하수에 유입하여 수질오염이 심화되고 있다. 또, 하수, 산업폐수, 분뇨, 축산폐수 및 농경지 유하수가 하천 및 지하수에 침입하여 수원을 오염시키고 질소, 인분이 증가하여 호소 저수지에 부영양화를 유발하고 있다. 일반적으로 정수과정은 취수, 침사, 응집, 침전, 여과, 염소 소독의 재래식 정수 방법이고 특수하게 원수의 오염이 심할 때에 활성탄(입상)을 사용하거나 이산화염소를 보조제로 사용하는 정수장이 있고, 여과도 완속여과지를 사용하고 있는 예가 있으며 또 오염이 심한 정수장에서는 전염소처리를 적용하는 예가 있다.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.10
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• pp.1035-1042
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• 2005

Granular Activated Carbon(GAC) is widely used in drinking water treatment. At S and B Water Treatment Plant, GAC is used in place of granular media in conventional rapid filters(GAC Filter-Adsorber) for removal of Disinfection By-products(DBPs). The primary focus of this study is on the performance of existing filter-adsorber, and their operation. It was found that F/A process removed turbidity as effective as sand system. The ratio of Hydrophobic DOM (HPO) and hydrophilic DOM (HPI) fraction in the raw water at S and B WTP was similar. Filter Adsorber presented earlier DOC breakthrough and steady state condition which was contributed by biodegradation during operation period. The removal efficiency of DBPs were used to evaluate the filter performance. The DBPs concentration of F/A treated water was below treatment goal level (THM < $80\;{\mu}g/L$, HAA < $60{\mu}g/L$). The removal efficiency of THM decreased rapidly during operation period. However, HAA were removed steadily regardless of the influent concentration of HAA. These results indicate that the removal of THM depend upon the adsorption mechanism while the removal of HAA depend upon biodegradation as well as adsorption. The decrease of adsorption capacity and characteristic value of GAC may be attributed to the effect of high organic loading, residual free chlorine, coagulants, manganese oxidants and frequently backwashing. This study has confirmed that Filter adsorber process can be considered as effective alternatives for the removal of DBPs, especially HAA.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.2
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• pp.205-212
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• 2008

This study aimed to investigate the biofilm formation, bacterial regrowth, and bacterial community structure in the granular-activated carbon (GAC) filter adsorbers (FAs) used in water treatment plants. In 2005 and 2006, raw water, settled water, GAC FA by depth, and filtered water were collected twice a year from water treatment plants (WTPs) B and S. The number of heterotrophic bacteria, including mesophilic and psychrophilic bacteria, in such collected waters was investigated along with the total number of coliforms therein. Heterotrophic bacteria were detected in most samples, mainly at the surface layers of the GAC FAs, and fewer such bacteria were found in the lower and bottom layers. An increase in the bacterial number, however, was observed in the samples from various depths of the GAC FAs in WTPs B and S compared with the surface layers. An increase in the bacterial number was also detected in the filtered water. This may indicate that there is a regrowth of the bacteria in the GAC FA. Considering, however, that heterotrophic bacteria were not found in the filtered water, it can be deduced that most bacteria are removed in the chlorination process. Coliforms were detected at the surface layer of the GAC FAs, but their regrowth was not observed. MicroLog systems were used to identify the bacteria community distribution. Eight genera and 14 species, including Pseudomonas spp., were detected in WTP B, and 8 genera and 9 species, including Aeromonas spp., in WTP S. Further studies are required to elucidate their role in the biofilms in water treatment processes.