• 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.

• Journal of Korea Soil Environment Society
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• v.2 no.2
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• pp.61-72
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• 1997

This research aims to remove the heavy metals, nonbiodegradable COD(NBDCOD), and color using the coal waste. The experimental by heat treatment was performed to advance the adsorption capacity. The results are as follows ; i) The coal waste had the adsorption capacity of heavy metals and the rates were in the range of 20 to 30 percents. ii) The heat treatment was the optimum condition that the reaction time was 6 hours at $500^{\circ}C$, , iii) In the column experimen, non-treated coal waste removed the COD and color in the range of 20 to 60 percents. iv) Heat-treated coal waste showed higher removal rate of the color in biological effluent, and heavy metal and COD removal rates were changed by the filteration rates.

• 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.

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.1
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• pp.13-21
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• 1996

For treating tannery wastewater containing high sulfate and heavy metals, test was performed to assess their performance, competition between SRB (sulfate reducing bacteria) and MPB (methane producing bacteria), and the activity of MPB according to change of chromium concentrations. COD removal efficiency was above 70% at VLR (volumetric loading rate) of 2.0 gCOD/I.day and HRT (hydraulic retention time) of 18hrs at $35^{\circ}C$. In the competition between SRB and MPB, about 15% of the removed COD was utilized by SRB in the begining, but it became 43% at the end. It indicated that MPB was strongly suppressed by the occurrence of significant sulfate reduction since a large electron flow was uptaken by SRB. For the entire experiment, removal efficiencies of chromium concentration were more than 90%. Despite high removal efficiencies of chromium concentration, performance of reactor did not change significantly during the experimental periods. Expecially, chromium (III) is tannery wastewater is less toxic than chromium (VI).

• KSBB Journal
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• v.15 no.4
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• pp.370-374
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• 2000

Some bacterial strains isolated from activated sludges and media and type cultures were cultivated in a pharmaceutical wastewater and a paperboard wastewater and added during batch treatment of those wastewaters in order for these strains to increase the treatment efficiency. Bacillus sp(PC-3) isolated from the charcoal media of the pharmaceutical wastewater plant grew remarkably over there strains in that wastewater and the viable cell count after 24hr cultivation was $1.1{\times}10^6m/L$. Bacillus subtills KCTC 1028 a type strain grew best in the paperboard wastewater and the viable cell count after 24hr cultivation was $1.1{\times}10^7m/L$. Addition of PC-3 in a batch treatment of the pharmaceutical wastewater increased COD removal by 18% after 8 day. And addition of Bacillus subtills KCTC 1028 in a batch treatment of the paperboard wastewater increased COD removal by 14% only after 24hy Bacillus subtills DCTC 1028 was though to be able to be produced economically using alcohol distillery wastewaters from starch material.

• Proceedings of the KAIS Fall Conference
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• 2006.11a
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• pp.324-327
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• 2006

COD 제거효율은 각 조의 부처꽃을 제외한 대조군의 경우 물상추 56%, 달뿌리풀 48%, 미나리 41%의 제거효율을 보이고, 발포유리가 첨가된 조의 경우는 물상추 69%, 달뿌리풀 68% 미나리 62%의 제거효율을 보임으로써 발포유리를 첨가한 조의 COD 제거효율이 대조군 보다 높았다. T-N의 제거효율은 발포유리를 첨가한 조의 경우 부처꽃 91%, 달뿌리풀 93%와 발포유리를 첨가한 혼합조가 94%의 높은 T-N 제거효율 보임으로써 모든 질소성분이 제거된 것으로 사료된다. T-P의 제거효율은 대조군의 부처꽃 35%, 달뿌리풀 8%이며, 발포유리를 첨가한 조의 부처꽃 78%, 달뿌리풀 43%로 발포유리를 첨가한조의 T-P 제거효율이 대조군 보다 높았다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.368-372
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• 2008

UV공정은 NaCl 첨가량 증가에 따라 RhB 분해율이 감소하였고, 전기분해 공정에서는 증가하는 경향을 보였으나 전기/UV 공정에서 NaCl 농도가 0.25 g/L까지 RhB 분해속도가 증가하였으며 최적 NaCl 농도는 0.25 g/L로 판단되었다. UV와 전기분해 단일 공저의 COD 제거 합보다 전기/UV 공정에서의 COD 제거율이 높아 복합 공정에 대한 시너지 효과가 나타나는 것으로 사료되었다.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.648-655
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• 2007

UV/H_2O_2$, $O_3$, $O_3/H_2O_2$, $UV/H_2O_2/O_3$ processes were tested for the removal of COD and color from terephthalic acid wastewater. COD removal efficiencies were 10, 48, 56, 63% in the $UV/H_2O_2$, $O_3$, $O_3/H_2O_2$, $UV/H_2O_2/O_3$ process respectively. Color removal efficiency of $UV/H_2O_2$ process was 80% and $O_3$, $O_3/H_2O_2$, $UV/H_2O_2/O_3$ processes were almost more than 99%. Terephthalic acid, isophthalic acid and benzoic acid were completely destructed in terephthalic wastewater within 120 min by $UV/H_2O_2/O_3$ process and shows high COD and color removal efficiencies. The optimum concentration of $H_2O_2$ dosage was found to be 0.5 M, 25 mM and 5 mM for $UV/H_2O_2$, $O_3/H_2O_2$ and $UV/H_2O_2/O_3$ processes respectively, Organic destruction efficiency was enhanced and also reducing the consumption of $H_2O_2$ dosage by combining UV, $H_2O_2$ and $O_3$ process.

• KSBB Journal
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• v.16 no.6
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• pp.573-578
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• 2001

The effects of organic supplement (acetate) and dissolved oxygen concentration on the nitrification rate of wastewater were investigated in the 27.7 L pilot-scale airlift biofilm reactor with the granular activated carbon media of 0.613 mm diameter. The ammonium oxidation rate increased stepwise up to 5 kg N/㎥$.$d at the riser air velocity of 0.063 m/s, when the air velocity and the ammonium loading rate were raised alternately. The nitrite build-up was observed during the early stage of the biofilm formation, which disappeared after the reactor operation of 128 days. As increasing the organic loading rate, the organic oxidation rate increased up to 25.0 kg COD/㎥$.$d with the removal efficiency of 94% but the oxidation rates of ammonium and nitrite decreased. The oxidation rates of ammonium and nitrite increased with the dissolved oxygen concentrations. When the pure oxygen was sparged, the ammonium oxidation rate was almost five times higher than that with air at the same velocity.

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.139-146
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• 1998

The characteristics of color and COD removal for dyeing-wastewater using electrochemical reaction were investigated. >From the result, the removal efficiency of color and COD were increased with increase of temperature, decrease of electrode distance, increase of electrolyte concentration and increase of potential and these were obtained above 99%, above 75% within 30 min, individually. Cause of higher COD removal efficiency, it is more suitable that dyeing-wastewater is treated by electrolytic treatment prior to biological treatment. It is concluded that the electrolytic treatment of dyeing-wastewater can be used as the effective and economical method in practical treatment.