• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.1
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• pp.49-57
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• 2009

This research examined the effect of ammonia nitrogen loading rate(NVLR) on the anaerobic digestion of slurry-typed swine wastewater. The anaerobic reactor was used an upflow anaerobic sludge blanket (UASB) process. This UASB reactor was operated at a NVLR of $0.02{\sim}0.96kg{NH_4}^+-N/m^3/day$. The methane content showed the range of 73.3~77.9% during the steady state period. Free ammonia(FA) concentration increased over inhibition level as pH increase from 7.3 to 8.2. However, in consideration of methane content, methane producing bacteria (MPB) inhibition by FA and total ammonia(TA) was not observed. A stepwise increase of the NVLR resulted in a deterioration in the COD removal rate in UASB reactor. The COD removal rate were 60% for NVLR up to $0.55kg{NH_4}^+-N/m^3/day$. As the NVLR increased from 0.09 to $0.96kg{NH_4}^+-N/m^3/day$, the biogas production rate varied from 3.71 to 9.14L/d and the methane conversion rate of the COD varied from 0.32 to $0.20m^3CH_4/kg$ COD removed. Consequently, in considerations of FA concentration, COD removal rate, and $CH_4$ production rate, the UASB reactor must be operated to lower than $0.40kg{NH_4}^+-N/m^3/day$ of NVLR.

• KSBB Journal
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• v.6 no.4
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• pp.345-350
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• 1991

The purpose of this study is to investigate biomass characteristics and organic removal efficiency by changing superficial upflow velocity and organic loading rate in treating alcoholic distillery wastewater. Since the biomass concentration and the thickness of biofilm are very sensitive to superficial upflow velocity, a high concentration of biomass could be achieved by decreasing superficial upflow velocity that lowered the organic removal efficiency. Therefore, superficial upflow velocity should be controlled as to give optimum conditions and removal efficiency. Generally, activated sludge system shows 70% COD removal efficiency at$1.5kgCOD/m^3{\cdot}day$, but the fluidized-bed biofllm reactor shows 80% COD removal efficiency even at 6kgCOD/$m^2{\cdot}day$.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.451-456
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• 1998

By grafting acrylic acid, fumalic acid and maleic acid onto chitosan, graft copolymers, CsAa, CsFa and CsMa, respectively were prepared for potential uses as flocculants in waste water treatment. When 40 ppm of each grafted chitosan sample was added into the waste water, CsMa showed the best removal rate of COD and suspended solids(SS), followed by CsFa and CsAa and chitosan. The transmittance and removal rate of COD and SS were the highest at pH 5. All grafted chitosan exhibited better performance than chitosan itself, resulting from the amphiphilic property of grafted chitosan copolymer with carboxy groups.

• Korean Chemical Engineering Research
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• v.53 no.1
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• pp.71-77
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• 2015

A fluidized biofilter was filled with Pseudomonas sp. and Bacillus cereus/thuringiensis-fixed waste-tire crumb media and was run to treat authentic textile-dyeing wastewater mixed with alkaline polyester-weight-reducing wastewater. As a result, its removal efficiency of $COD_{Cr}$ and color were 75~80% and 67%, respectively. In addition, upon constructing hybrid-recirculating system composed of the fluidized biofilter and a 450 W-UV/photocatalytic reactor, only fluidized biofilter was run bypassing UV/photocatalytic reactor at stage I. Subsequently, the hybrid system was continuously run at stage II-i, ii and iii. At stage II-i, the total removal efficiency of $COD_{Cr}$ was enhanced to be 80~85%, compared to 75% at stage I, owing to 20~30% removal efficiency of the UV/photocatalytic reactor. However, at stage II-i, the total removal efficiency of color was enhanced to be 65~70%, compared to 45~65% at stage I, even though the removal efficiency of the UV/photocatalytic reactor was tantamount to merely 0~5%. As far as the removal efficiency of fluidized biofilter of the hybrid-recirculating system is concerned, its removal efficiency of color was enhanced by the synergy effect of the hybrid-recirculating system unlike $COD_{Cr}$. Besides, despite of the increase of hybrid-recirculating system-recycle ratio, the deactivation of photo-catalytic activity was scarcely observed to eliminate the color while its irreversible deactivation was observed to eliminate $COD_{Cr}$.

• The Journal of the Korea Contents Association
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• v.6 no.10
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• pp.34-40
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• 2006

In this study, the treatment of organic matters and nutrients like Nitrogen and Phosphorus with sequencing batch reactors (SBR) was conducted. The following conclusions can be summarized from the study. The influent BOD concentration was varied 19.6 to 40.0mg/L and the effluent was 3.0 to 14.8mg/L. The variations of BOD removal efficiency during the experimental period was $47.9{\sim}88.4%$ and the average was 80.8%. The average removal efficiency was stabilized with the passage of time. Also the COD concentration was flowed into as $12.2{\sim}32.0mg/L$ and the effluent concentration was varied 3.3 to 18.6 mg/L, and then the average COD removal efficiency was 57.3%(minimun 19.2% and maximum 78.6%). But fortunately, the COD removal efficiency was also stabilized as 70.2% after 79days. In the case of T-N, the influent concentration range was $7.53{\sim}14.99mg/L$ and the effluent concentration was 6.59mg/L(the average removal efficiency was 40.3%) until the first experiment time 79days. But after normalizing the system, it was 4.44mg/L (the average removal efficiency was 56.4%). Also the influent T-P concentration was varied from 0.77 to 1.91mg/L and the effluent concentration was $0.26{\sim}1.53mg/L$. The removal efficiency was varied from 5.3 to 71.7%. considerably, therefore the average removal efficiency was 42.6%. The reason was concluded that the sludge wasn't discharged for increasing MLSS concentration.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.279-284
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• 2013

In this study, the feasibility of a single-stage thermophilic aerobic process for the treatment of high-strength food wastewater produced from the recycling process of food wastes was examined to substitute anaerobic digestion process. Also, the removal and stability of thermophilic aerobic process were assessed according to the changes of hydraulic retention times (HRTs) and organic loading rates (OLRs). When the OLR increased from 9.2 to $37.2kgCOD/m^3d$, a pH value in R1 (HRT : 5 d) significantly decreased to 5.0, due to the organic acid accumulation. On the other hand, the pH value in R2 (HRT : 10 d) was stable and R2 showed the high removal of COD, organic acid and lipid, even though the OLR increased from 4.6 to $18.6kgCOD/m^3d$. In R1, the COD loading rates for COD removal was suddenly dropped, as the COD loading rate increased from 18.6 to $28.4kgCOD/m^3d$. In contrast, R2 showed that the COD loading rates for COD removal increased with regard to increment in the loading rates of 3.61, 7.05, 9.43 and $12.2kgCOD/m^3d$, indicative of the high COD removal efficiency. Therefore, the results demonstrated that over 10-d HRT, the high concentration of raw food wastewater was efficiently treated in the single-stage thermophilic aerobic process.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1654-1660
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• 2009

Two different cutting-oils from H and B companies which are sold as an eco-friendly cutting-oils were selected and the biodegradability of these commercially available cutting-oils was evaluated by the sequencing batch reactor (SBR) processes. The cutting-oil wastes ($H_1$) pre-treated by coagulation/flocculation was used as an influent to SBR. When the F/M ratio was operated 0.04 to 0.08kgCOD/kgMLSS d, removals of $BOD_5$and $COD_{Cr}$were above 97% and 91%, respectively. T-N and T-P removals were above 76% and 81%, respectively. If the diluted cutting-oil wastes ($B_1$) was used as an influent of the SBR, $COD_{Cr}$removals were above 77% at the F/M ratio of 0.01-0.02kgCOD/kgMLSS d. After the cutting-oil wastes was treated by coagulation/ flocculation ($B_2$), $COD_{Cr}$removals was above 85%. If the pre-treated cutting-oil wastes were mixed with a synthetic wastewater ($B_3$) and fed into the SBR in order to mimic the real wastewater treatment plant situation, $BOD_5$and $COD_{Cr}$removals were above 97%, 91%, respectively. T-N and T-P removals were above 79% and 76%. The ratio between $BOD_5$and $COD_{Cr}$, ($COD_{Cr}$-$BOD_5$)/$COD_{Cr}$, indicating the biodegradability of effluent of the SBR, was calculated to 85% and 61%. This means that significant amounts of non-readily-biodegradable organic compounds in the effluent of $H_1$, $B_3$are still present.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.3
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• pp.126-133
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• 2004

This study is performed to examine the removal efficiency of organic materials,$NH_4-N$ and P in Swine-Wastewater Treatment using Hybrid-process. It named SBR process, Hybrid-process as RunI(SBR), and Run II(Struvite Tank-SBR), and compared the removal efficiency of each Run. The removal efficiency of the organic materials in each Run is like this; In Run I, TS, VS and COD was 43%, 39%, and 70%, respectively. And in Run II, TS VS, and COD was 52%, 52%, and 82%, respectively. It shows that the removal efficiency of Run II using Strutive Tank is higher. And as for the removal efficiency of $NH_4-N$ and T-P in each Run, Run II using Strutive Tank was 90% and 57%, higher than 56% and 49% of RunI. Especially for $NH_4-N$, Run II showed much higher efficiency, and this proved that Strutive Tank was very efficient process of all for the removal of N and P. As a result of this study, Hybrid-process that combines Strutive Tank and SBR is proved to be a very good process in Swine Wastewater Treatment.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.144-148
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• 2002

This study was carried out to investigate sewage treatment efficiencies using water hyacinth (Eichhornia crassipes) and watercress (Oenanthe Javanica). In the hyacinth system about 30% of COD introduced was removed during 2 days of hydraulic retention time, and about 30$\sim$50% of COD was removed in the watercress system during 1.2$\sim$2 days of hydraulic retention time. Therefore, COD loading of $76\sim170$ kg $COD/ha{\cdot}day$ was removed during 2$\sim$3 days of hydraulic retention time at the 0.18 $m^2$ area in the water hyacinth-watercress continuous system. Also 40$\sim$50% of N and P in the sewage were removed in the tested water hyacinth-watercress system Although COD, N and P concentrations in the final effluent were still higher than the limits of waste discharge, applicability of this waste water treatment system should be further investigated as an alternative method far small scale sewage treatments.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.350-354
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• 2008

전기/UV 공정에 사용하기 위해 일반적인 살균 램프인 UV-C 램프와 오존도 같이 발생하는 오존 등의 RhB 분해능을 고찰한 결과 오존 램프의 RhB 제거율이 UV-C램프보다 높은 것으로 나타났다. 전해질을 첨가하지 않은 전기/UV 공정에서 최적 전류는 1 A로 나타났다. 전기/UV 공정에서 RhB 제거의 경우 전기분해 공정과 UV 공정의 단일 공정의 RhB 농도감소와 전기/UV 복합 공정의 RhB 제거는 같아 공정의 시너지 효과는 관찰되지 않았다. 그러나 COD의 경우 전기분해 공정과 오존 램프에 의한 단일 공정의 COD 제거보다는 전기/UV 공정의 COD 제거농도가 높아 시너지 효과가 나타나는 것으로 사료되었다.