• Journal of Environmental Science International
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• v.15 no.9
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• pp.829-834
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• 2006

This research aims to investigate the behavior of organic matter that causes bacterial re-growth and the formation of disinfectant by-products such as THM in water treatment, and to optimize conditions for a more efficient and conventional water facility. THM removed 51 % and 12 % through coagulation/sedimentation and filtration using a selected conventional system. In this experiment, the removal ratio of DOC was highest at 68 % when the Gt value was 42,000 and lowest at 41 % when the Gt value was 30,000. 77-84 % of total DOC was removed during coagulation/sedimentation, and 15-23 % was removed during filtration. When Gt values were between 30,000 and 66,000, over 50 % of high molecular matter above 10 K during coagulation/sedimentation was removed. Turbidity removed 98 % when the G1 value was 66,000. As the Gt value increased, the turbidity removal ratio increased. Turbidity removed over 20 % during the filtration process.

• Journal of environmental and Sanitary engineering
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• v.12 no.1
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• pp.69-75
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• 1997

Biological drinking water treatment is widely used in Europe for the removal of ammonia nitrogen and organics. During the last 16 years, the deterioration of the quality of surface waters used to produce drinking water has resulted in the widespread use of ozone-biological treatment in Korea. This study were conducted to determine the effect of media weight and preozonation on the biodegradability enhancement in biological fluidized bed(BFB) using Han river water. When the carbon weight was increased, $NH_{3}-N$ and DOC removal increased, but turbidity and SS removal decreased. To remove turbidity and SS, the bed depth in 40% expansion rate/total bed depth was very important. Preozonation of raw water was not effective in $NH_{3}-N$, but increased in biodegradable organic fraction about 10-30% with 0.425-0.85 mg $O_{3}/mg$ DOC.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.63-67
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• 2004

A field pilot study on remediation of diesel-contaminated soil by hot air injection/extraction process constructing soil piling system was conducted to evaluate the effects of hot air on the removal of diesel and each constituent. After the heating process of 2 months, the equilibrium temperature of soil reached to 10$0^{\circ}C$ and soil TPH concentration was reduced to about 72% against the initial concentration. Additional extraction process of 2 months induced the continuous extraction of residual diesel and the increment of microbial activity, which made soil TPH concentration reduced to 95%. In addition biological removal of non volatile constituents in diesel was verified indirectly and the removal pattern of each DRO(diesel range organic) as soil temperature was explained.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.966-972
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• 2007

A novel organoclay has been developed with aluminium-pillared clay modified with an amphoteric surfactant, N-Dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (DDAPS). This novel organoclay is expected to have phosphorus removal capacity as well as organic and inorganic contaminant removal capacity, due to aluminum inside the clay structure. It also exhibited less surfactant desorption than conventional cation surfactant-based organoclays. Phosphorus in water can be decreased from 0.2 mg/L to 0.0012 mg/L in 27 hours with this organoclay. Also, cadmium could removed from water using this proposed organo-clay. Experiments were performed under various pHs and amphoteric surfactants sorption capability was the highest at pH 5 when more of the amphoteric surfactant head group took on positive charges.

• Journal of Wetlands Research
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• v.4 no.1
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• pp.87-95
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• 2002

The objective of this study is to treat contaminated stream by using a UFBR(upflow fixed biofilm reactor) packed with waste-concrete media. This system was tested from June 1999 to January 2000. Over $20.0^{\circ}C$, $COD_{cr}$ removal efficiency did not affected with organic loading rate while, $COD_{cr}$ removal efficiency decreased about 7% with decrease of temperature from $27.0^{\circ}C$ to $8.7^{\circ}C$. Under $16^{\circ}C$, TKN removal efficiency was affected with TKN loading rate. The proposed model apply to mass balance equation of fixed biofilm reactor for predicting effluent was well satisfied with measured value($R^2=0.94$).

• Journal of Environmental Science International
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• v.12 no.10
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• pp.1095-1100
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• 2003

In this study, it was performed using submerged nonwoven bioreactor(SNBR) for removal of organic matter, nitrogen and phosphate under different aeration intervals(intermittent aeration). We applied the SNBR at the cheap nonwoven fiber module instead of the expensive membrane. The SUBR was mainly made up of an activated sludge reactor and a transverse flow nonwoven module, with an innovative configuration being in application between them. In case of sewage, the aeration conditions experimented consist of continuous aeration and 60min/60min, 120min/60min, 120min/120min of aeration/nonaeration time intervals, respectively. In case of landfill leachate, the intermittent aeration condition was 120min/120min at aeration/nonaeration. Consequently, a high COD removal rate (about 94%) was achieved in sewage and leachate. Although nutrient removal rate was relatively high without any additional chemicals.

• KSBB Journal
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• v.19 no.2
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• pp.143-147
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• 2004

Biodegradation of dimethyl sulfide (DMS) was studied in a batch culture using Gordonia sihwaniensis PKL-1 isolated from a compost biofilter after 100 days of operation for the removal of volatile organic compounds. Optimal pH and temperature for the removal of DMS were 7 and $25^{\circ}C$, respectively. The Michaelis-Menten kinetic constants for DMS removal, $\upsilon_{max}$ and $K_s$, were 0.0016 mg/(mg-protein)ㆍhr, and 8.05 mg/L, respectively.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.209-213
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• 2005

Slow sand filtration processes amended with 5 and 10cm GAC layers at top was compared to same process at bottom in a pilot study for humic substances removal. In case of 5cm GAC layer, the process amended at bottom was superior to the process at top in DOC and UV254nm removal and same trends were observed in case of 10cm GAC layer. Head loss developments of the process GAC at bottom were higher than the process GAC at top so that maintenance of the process GAC at top is easier than the process GAC at bottom.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.6
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• pp.687-692
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• 2006

This experiment was performed to evaluate the characteristics of BNR system performance, behavior of pollutants as organic and nitrogen at each basin and the effects of C/N ratio on biological nitrogen removal with methanol as an external carbon source for a low C/N ratio municipal wastewater. A lab-scale $A_2O$ system by employing the aerobic basin with the fluidized polyurethane media, which was $10{\sim}20$ mm rube type like a sponge, was used. The aerobic basin was hybrid type to be suspended and fixed biomass. The obtained results from this study were as follows; When no methanol was added, suspended biomass was 3 times more than that of the fluidized media in this system(total biomass 80 g). Biomass growed by an external carbon was firstly attached on media, and then suspended. $COD_{Cr}$ concentration for the effluent was a range of 13 to 29 mg/L regardless of pouring an external carbon. For nitrogen, the effluent concentration was $20.0{\sim}35.9mg/L$(removal efficiency; 18%) in case of no addition of an external carbon, but was $2.5{\sim}9.0mg/L$(removal efficiency ; $71{\sim}83%$) with addition of methanol. For the characteristics of pollutants removal, most of $COD_{Cr}$ were removed at the anaerobic basin when no external organic carbon was added, and were removed at the anoxic basin in case of adding external organic carbon but at the aerobic basin in case of adding excess external organic carbon. On the other hand, most TIN(total inorganic nitrogen) were removed at the anaerobic basin when no external organic carbon was added, but when an external organic carbon was added, they were removed at the anaerobic basin under unstable condition and at the anoxic basin under stable condition.

• KSBB Journal
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• v.18 no.3
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• pp.211-216
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• 2003

The removal yield of dissolved organic matter in drinking water by biological activated carbon (BAC) process was investigated. The tested processes wer raw water-AC process (BAC1), raw water-ozonation-BAC process (BAC2), and raw water-ozonation-coagulation/sedimentation-BAC process (BAC3). The amounts of organic matter was measured as dissolved organic carbon (DOC), ulta-violet radiation at 254 nm wavelength ($UV_{254}$), total nitrogen (T-N), ammonia nitrogen (NH_3$-N), and total phosphate (T-P). As a results, 30.7% DOC was removed by BAC2 process, which showed higher removal efficiency than BAC1 or BAC3 processes. The removal yield of $UV_{254}$ in BAC1, BAC2, and BAC3 processes were observed as 45.3%, 44.6%, 58.4%, respectively. And the removal yield of ammonia nitrogen were 66%, 81%, 29% in each BAC processes. The optimal empty bed contact time (EBCT) of BAC processes was estimated as 10 minute. This study has shown that BAC process combined with ozone treatment was efficient for removing dissolved organic matter in water.