• Journal of Environmental Science International
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• v.15 no.5
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• pp.439-446
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• 2006

The effluent discharge standards of industrial wastewater has become more stringent since 2003. Many industrial wastewater treatment plants has been upgraded to advanced treatment facilities. There are high concentrations of nitrate(>200 mg/L) and ammonium(>50 mg/L) nitrogen in the acrylic fiber wastewater of H textile Co. Wastewater from acrylic fiber industry containing acrylonitrile, which may affect the subsequent biological treatment process. Manufacturing of acrylic fiber also produces shock loadings. Excessive acrylonitrile and polymer debris produced in the polymerization process was screened, coagulated with CaO and settled down. A preaeration system was added to treat this high pH effluent to remove volatile organic compound and ammonia nitrogen by the air stripping effect. it was found that nitrification rate was not sufficient in the Anoxic/Oxic(AO) process. One denitrification tank was converted to nitrification reactor to extend HRT of nitrification. Nitrification rate of ammonia nitrogen was promoted from 32% to 67% by this modification and effluent nitrogen concentration was well satisfied with the effluent standards since then.

• Journal of Korean Society on Water Environment
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• v.25 no.4
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• pp.530-538
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• 2009

The Oxic-Settling-Anaerobic (OSA) treatment process, a modified Conventional Activated Sludge (CAS) process, was developed for the purpose of sludge reduction. The insertion of a sludge holding tank into a sludge return line, an anaerobic reactor, forming an OSA process, may provide a cost-effective way of reducing excess sludge production during a process. The OSA process was evaluated for its sludge reduction ability by kinetic parameter and mass balance, with an observed excess sludge reduction of 63.5%, as $P_{X.VSS}$, compared with the conventional activated sludge process.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.125-128
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• 2000

A recycling reactor system operated under sequential anoxic and oxic conditions for the swine wastewater has been developed, in which piggery slurry is fermentatively and aerobically treated and then part of the effluent recycled to the pigsty. This system significantly removes offensive smells (at both pigsty and treatment plant), BOD and other loads, and appears to be costeffective for the small-scale farms. The most dominant heterotrophs were Alcaligenes faecalis, Brevundimonas diminuta and Streptococcus sp. in order while lactic acid bacteria were dominantly observed in the anoxic tank. We propose a novel monitoring system for a recycling piggery slurry treatment system through neural networks. Here we tried to model treatment process for each tank(influent, fermentation, aeration, first sedimentation and fourth sedimentation tanks) in the system based on population densities of heterotrophic and lactic acid bacteria. Principle component analysis(PCA) was first applied to identify a relation between input(microbial densities and parameters for the treatment such as population densities of heterotrophic and lactic acid bacteria, suspended solids (SS), COD, $NH_3-N$, ortho-P, and total-P) and output, and then multilayer neural networks were employed to model the treatment process for each tank. PCA filtration of input data as microbial densities was found to facilitate the modeling procedure for the system monitoring even with a relatively lower number of input. Neural networks independently trained for each treatment tank and their subsequent combinatorial data analysis allowed a successful prediction of the treatment system for at least two days.

• Journal of Environmental Science International
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• v.15 no.6
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• pp.571-577
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• 2006

This study make a comparison between the phosphorus removal performance of FNR(Ferrous Nutrient Removal) process and A/O process by the laboratory experiments. For simultaneous removal of phosphorus, iron electrolysis was combined with oxic tank. Iron precipitation reactor on the electrochemical behaviors of phosphorus in the iron bed. The phosphorus removal in FNR process was more than A/O process. Iron salts produced by iron electrolysis might help to remove COD and nitrogen. And the demanded longer SRT is the more removes the removes COD, nitrogen, and phosphorus. Also, FNR process of sludge quantity more reduce than A/O process to input cohesive agents.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.1
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• pp.14-20
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• 2006

In this study, the feasibility of simultaneous removal of organic materials and nitrogen in the waste-water from fisheries processing plant was evaluated using entrapped mixed microbial cell technique(EMMC) process. The experiment was performed using activated sludge from municipal sewage treatment plant which was immobilized with gel matrix by cellulose triacetate. It was found that the stable operation at the treatment system which is composed of anoxic and oxic tank, was possible when the organic and nitrogen loading rates were increased stepwise. The organic and nitrogen loading rates were applied from 0.65 to $1.72kgCOD/m^3/d$ and from 0.119 to $0.317kgT-N/m^3$ with four steps, respectively. The maximum nitrogen loading rate which could satisfy the regulated effluent standard of nitrogen concentration, was $0.3kgT-N/m^3/d$. The removal efficiency of total nitrogen was decreased apparently as increasing nitrogen loading rates, whereas the removal efficiency of ammonium nitrogen was effective at the all tested nitrogen loading rates. Therefore, it was concluded that nitrification was efficient at the system. Nitrate removal efficiency ranged from 98.62% to 99.51%, whereas the nitrification efficiency at the oxic tank ranged 94.0% to 96.9% at the tested loading rates. The removal efficiencies of chemical oxygen demand(COD) and those of total nitrogen at the entire system ranged from 94.2% to 96.6% and 73.4% to 83.4%, respectively.

• Journal of Environmental Health Sciences
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• v.32 no.1 s.88
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• pp.89-95
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• 2006

This study was conducted to improve an effect of phosphorus removal using FNR(Ferrous Nutrient Removal) process which had iron precipitation reactor and to analyze the iron corrosion. For simultaneous removal of phosphorus, iron electrolysis was combined with oxic tank. In this study, The removal efficiency of phosphorus increased with an increase voltage in iron precipitation reactor. The distance of 15mm between the two iron bed in each tests influence the concentration of remaining phosphorus most. The extensive surface area of iron bed is the more removes the phosphorus. In this test the $400\;cm^2$ of surface area was proved to be the most removal efficient.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.8
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• pp.780-786
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• 2010

The bacterial community structure in biological reactor in wastewater treatment system was investigated by denaturing gradient gel electrophoresis (DGGE) and fluorescent in situ hybridization (FISH). Samples were collected at different three points in wastewater treatment system. Through treatment processes, BOD (biochemical oxygen demand) and COD (chemical oxygen demand) of was removal efficiency was 83.1~98.6%, 67.2~85.2% respectively. Microbial community of aerobic tank and oxic tank were similar but anoxic tank was different (RRP group was increased about tripple) by DGGE and FISH in sludge (2007 October and 2008 January). Samples in 2007 October and 2008 January were dominant ${\alpha}$-Proteobacteria and CF group respectively. Sludge in 2008 April were different comparing former results dominant others as 65~80%. Others group was dominant. Eubacteria by FISH with the probe EUB338 was about $1.7{\sim}7.6{\times}10^9\;cells/mL$. It could be successfully observed bacterial community in biological wastewater system.

• Korean Journal of Microbiology
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• v.47 no.1
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• pp.56-65
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• 2011

Culture-independent microscopic observations and 16S rDNA analyses were applied to describe the bacterial community inherent to the biofilm structure of the RABC (Rotating Activated Bacillus Contactors) process for swine butchery wastewater treatment. The ratios of Gram-positive bacterial counts to total bacterial counts of the RABC process were significantly increased in the last aeration tank as well as returned sludge, while those of the existing A2O (Anaerobic-Anoxic-Oxic) process maintained constant from aeration tanks to returned sludge. Totally nine phyla were recovered by 16S rDNA analysis, two of which were major groups: the Proteobacteria (64.1%) and the Actinobacteria (18.4%). The third major group was the endospore-forming Firmicutes (5.4%). The remaining six minor groups are the Bacteroidetes (3.3%), the Chlorobi (2.2%), the Nitrospirae (1.1%), the Chlorofleix (1.1%), the Acidobacteria (1.1%), and the Fusobacteria (1.1%). The ratio of endospore-forming bacteria was 19.4%, which was composed of the members of the Firmicutes phylum (5.4%) and the Intrasporangiaceae family (14.0%) of the Actinobacteria phylum. Nitrifying and denitrifying related- and phosphorus accumulating related-sequences were composed of 6.5% and 5.4% of total community, respectively, these could mean the high capacity of the RABC process to remove odor compounds and reduce eutrophication by efficient removing inorganic nutrients.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.7
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• pp.479-484
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• 2013

This study was performed to examine the effect of copper on the biodegradability, nitrification, denitrification and oxygen uptake rate (OUR) using batch reactor and continuous flow stirred tank reactor (CSTR) of anaerobic/anoxic/oxic ($A_2/O$). The results of this study can be summarized as follows. In the case of the effect of copper on organic treatment, the bad effect initiated when it was above 4.5 mg/L copper with batch reactor and above 2.0 mg/L copper with CSTR. Concerning the case on nitrification and removal of nitrogen, it showed bad effect when copper was above 4.5 mg/L with batch reactor for nitrification and 1.0 mg/L with CSTR for the removal of nitrogen. The bad effect on the removal of phosphorus began when it was 4.5 mg/L copper with batch reactor and 2 mg/L copper with CSTR. In the case of OUR, it decreased as microbial activity was affected when copper concentration was above 1.5 mg/L in both case of batch reactor and CSTR.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.4
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• pp.228-233
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• 2015

This study was performed to examine the effect of zinc on the biodegradability, nitrification, denitrification and oxygen uptake rate (OUR) using batch reactor and continuous flow stirred tank reactor (CSTR) of anaerobic/anoxic/oxic ($A^2/O$). The results of this study can be summarized as follows. In the case of the effect of zinc on organic treatment, zinc had no effect up to 12 mg/L with batch reactor but biodegradability was lowered when it was above 3.0 mg/L with CSTR. Concerning the case on nitrification and removal of nitrogen, nitrification rate was lowered when zinc was above 6.0 mg/L with batch reactor and removal rate of nitrogen was lowered when zinc was above 3.0 mg/L with CSTR. Removal rate of phosphorus was lowered when it was above 6.0 mg/L zinc with batch reactor and above 3.0 mg/L zinc with CSTR. In the case of OUR, it decreased as microbial activity was affected when zinc concentration was above 3.0 mg/L in CSTR.