• Journal of Korean Society of Environmental Engineers
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• v.22 no.5
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• pp.837-847
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• 2000

For the treatment of wastewaters generated from beer industry and petrochemical company with high organic and nitrogen contents, laboratory scale of A/O Pure-Oxygen Biofilm (POB) process was developed and studied by means of the comparative economic analysis with extended aeration process. When the wastewater of beer company was initially treated by the A/O POB process in the ranges of 70 to 150 mg TOC/L diluted with tap water, higher than 92% of TOC removal was accomplished in the all ranges. In case of petrochemical wastewater, the initial TOC removal was as low as 52%, though, it increased to 86% after 32 days of operation and also the TKN removal marked 71% after 27 days. Continuous high removal rates were monitored in both the TOC and TKN parameters during the experimental period. Due to the cost for PSA (Pressure Swing Adsorption) setting and biomass supporting media installation, the initial construction cost of A/O POB process was 2.9 times higher than that of extended aeration process. However, the advantages such as low sludge production, no need for sludge recycling and low energy consumption allow the A/O POB process to have 2.5 times lower operation and maintenance costs. Consequently, in the long term of operation, it is likely that A/O POB process would show higher performance as well as cost effectiveness compared to extended aeration process.

• Journal of Life Science
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• v.23 no.10
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• pp.1273-1279
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• 2013

Aromatic hydrocarbons, such as phenol, have been detected frequently in wastewater, soil, and groundwater because of the extensive use of oil products. Bacterial strains (56 isolates) that degraded phenol were isolated from soil and industrial wastewater contaminated with hydrocarbons. GN13, which showed the best cell growth and phenol degradation, was selected for further analysis. The GN13 isolate was identified as Neisseria sp. based on the results of morphological, physiological, and biochemical taxonomic analyses and designated as Neisseria sp. GN13. The optimum temperature and pH for phenol removal of Neisseria sp. GN13 was $32^{\circ}C$ and 7.0, respectively. The highest cell growth occurred after cultivation for 30 hours in a jar fermentor using optimized medium containing 1,000 mg/l of phenol as the sole carbon source. Phenol was not detected after 27 hours of cultivation. Based on the analysis of catechol dioxygenase, it seemed that catechol was degraded through the meta- and ortho-cleavage pathway. Analysis of the biodegradation of phenol by Neisseria sp. GN13 in artificial wastewater containing phenol showed that the removal rate of phenol was 97% during incubation of 30 hours. The removal rate of total organic carbon (TOC) by Neisseria sp. GN13 and activated sludge was 83% and 78%, respectively. The COD removal rate by Neisseria sp. GN13 from petrochemical wastewater was about 1.3 times higher than that of a control containing only activated sludge.

• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.608-614
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• 2012

The effluent limitation of industrial wastewater is based on uniform regulatory criteria for effluent discharge facilities of all in Korea. But, an individual effluent limitation on each effluent discharge facility is widely applicable for regulation of industrial wastewater in US.EPA. To decide an individual effluent limitation, TBEL (Technology-based effluent limitation) and WQBEL (Water quality-based effluent limitation) are used. TBEL is based on the capability of a treatment technology to reduce the pollutants. WQBEL is based on ambient water quality standards. In this study, TBEL were derived for the pulp, paper and paper board manufacturing based on best practicable control technology currently available. It was suggested that effluent limitations were $BOD_5$ 4.7 mg/L, $COD_{Mn}$ 44.3 mg/L, SS 13.2 mg/L, TN 1.4 mg/L, TP 0.15 mg/L and best practicable control technology currently available (BPT) was neutralization, activated sludge treatment and coagulation and sedimentation for the pulp, paper and paper board manufacturing.

• Applied Chemistry for Engineering
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• v.23 no.3
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• pp.297-301
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• 2012

Microbial fuel cell (MFC) is the major of bio-electrochemical system which can convert biomass spontaneously into electricity through the metabolic activity of the microorganisms. In this study, we used an activated sludge as a microbial inoculum and then investigated the feasibility of using dairy wastewater as a possible substrate for generating electricity in MFC. To examine the performance of MFC as power generator, the characteristics on cell potentials, power density, cyclic voltammetric analysis and sustainable power estimation were evaluated for dairy wastewater. The maximum power density of $40\;mW/m^2$was achieved when the dairy wastewater containing 2650 mg/L COD was used, leading to the removal of 88% of the COD. The results from this study demonstrate the feasibility of using MFC technology to generate electricity while simultaneously treating dairy wastewater effectively.

• Applied Biological Chemistry
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• v.41 no.2
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• pp.181-186
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• 1998

The effects of sewage treatment on characteristics of sludge as a composting material were investigated for a year during the initial operation at the full-scale Chunan sewage treatment plant. Due to the shortage of design capacity of belt press, a sludge dewatering unit, non-volatile solids were recirculating and concentrating in the treatment plant, resulting in an increase of MLSS and a decrease in F/M ratio at the activated sludge system. Special attention is required for long term operations since the increase of non-volatile solids in the plant would deteriorates the treatment efficiency. The sewage sludge of the Chunan sewage treatment plant showed 79.5% of water content, 11.6% of organic content, and C/N ratio of 6.1, and contained As 1.8 mg/kg, Cd 27 mg/kg, Hg <0.1 mg/kg, Pb 54 mg/kg, T-Cr 370 mg/kg, and Cu 1,100mg/kg of heavy metals. In order to be used as raw material for optimum composting, the sewage sludge requires bulking agents for moistrure/porosity control and a carbon source for adjusting C/N ratio. However, the sewage sludge is not adequate as a soil conditioner after composing due to a high content of heavy metals. If the sewage sludge has to he used as a soil conditioner after composting, it as required to identify and remove tire industrial wastewater portions in tire influent of the plant since heavy metals in the influent were mostly concentrated in dewatered sludge.

• Journal of Industrial Technology
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• v.22 no.B
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• pp.109-115
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• 2002

This research was performed to investigate the COD removal efficiency and methane production in slurry-typed swine wastes using UASB(upflow anaerobic sludge blanket)reactor. The USAB reactor was operated from 0.8 through 3.3days of HRT in a range of 3 to 15 kg $TCOD/m^3/day$ of volumetric organic loading rate. The removal rate of TCOD was increased with the increase of the HRT. The removal rate of TCOD at an HRT over 2days, became greater than 68% with the methane contents being from 70 to 80%. Methane production rates were increased from 0.27 to $0.36m^3\;CH_4/kg$ CODrem. as HRTs were increased from 0.8 to 3.3days.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.345-350
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• 2006

This study investigated the removal of recalcitrant organics in dyeing wastewater using a fluidized bed reactor(FBR) that contained cell-immobilized pellets. The pellets were manufactured and condensing the gel phase by mixing PEG-polymer and cells to form micro-porous PEG-polymer pellets whose size were ${\Phi}\;4mm{\times}H\;4mm$ on average. An industrial activated sludge without any pre-adaptation was used for the cell immobilization because it gave an equivalent removal efficiency to a pre-adapted sludges. The feed was obtained from an effluent of a biological treatment plant, which contained $SCOD_{Cr}$ of 330 mg/L and $SBOD_5$ of 20 mg/L. The $SCOD_{Cr}$ removal efficiency was over 45% and the effluent $COD_{Mn}$ concentration was less than 100 mg/L at HRTs from 6 to 24 hrs. The optimum HRT in the FBR was determined as 12 hrs considering the removal efficiency and cost. When a raw wastewater containing 768 mg/L of $COD_{Cr}$ was fed to the FBR, the effluent $COD_{Cr}$ concentration increased only slightly, giving a 70% of $COD_{Cr}$ removal or a 97% of $BCOD_5$ removal. This indicated that the FBR had an excellent capability of biodegradable organics removal also. In conclusion, the FBR could be applied to textile wastewater treatment in place of an activated sludge process.

• Applied Chemistry for Engineering
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• v.17 no.1
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• pp.22-27
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• 2006

Thermal treatment and ozone oxidation methods were examined to reuse waste activated sludge (WAS) produced from a livestock wastewater treatment plant. Analysis of WAS property was made to study usefulness of the recycled waste as fertilizer. From the results of quantitative analysis, WAS particles were found to be composed of 44.25 wt% carbon, 8.43 wt% nitrogen, and 1.35 wt% phosphorus. It was confirmed that the inactivation of pathogenic microorganism was required from the quantitative analysis of microbes. From the results of TSS, COD, SCOD, and pathogenic microorganism measurement, the optimal operating conditions of thermal treatment and ozone oxidation were determined to be 70, 10 min and $0.6L\;O_3/L\;solution{\cdot}min$, 60 min, respectively. The optimized thermal treatment and ozone oxidation represented the efficient pathogen inactivation and particle dissolution, respectively. However, the two methods examined were not themselves sufficient but they need to combine with another treatment for the effective reuse of wastes.

• KSBB Journal
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• v.24 no.3
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• pp.296-302
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• 2009

This paper was investigated the research regarding the effects of several factors such as initial ammonium nitrogen concentration, aeration rate. biomass amount and C/N ratio on nitrification process using synthetic wastewater and activated sludge obtained from wastewater treatment facility. As a result, in high ammonium nitrogen concentration above 100 mg/L, the pH of wastewater was dropped to pH 6.8. The increases of initial ammonium nitrogen concentration, aeration rate and initial biomass amount were linearly enhanced the removal rate of ammonium nitrogen. In the condition of C/N ratio of 0 to 3, high ammonium nitrogen removal rate was obtained.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.8
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• pp.574-582
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• 2012

This study presents the concentrations of the polycyclic aromatic hydrocarbons (PAHs) listed as priority pollutants by United States Environmental Protection Agency (US EPA), in 98 sludges from 54 industrial wastewater treatment facilities of South Korea. The mean concentrations of ${\Sigma}_{16}PAHs$ were ranged from 32.5 ${\mu}g/kg-dw$ to 1189.3 ${\mu}g/kg-dw$ by industries, and the highest content was found in the petrochemical industry, followed by chemical, clothing manufacturing and dying, pulp and papermaking, secondary wastewater treatment, and food/beverage producing industries. Comparisons to the EU and Danish standards of ${\Sigma}_{16}PAHs$ in sewage sludge for land application showed only two samples (one from petrochemical, and the other from chemical industry) exceeded the limits. ANOVA test with PAH concentrations as variables revealed no statistically significant influences by industrial types and sampling time (i.e., seasonal variations). Pearson correlations between individual PAHs showed strong relationships (r>0.7) among 4-ring PAHs. Concentrations of acenaphthylene, anthracene, fluoranthene, benzo(a)anthracene, benzo(f)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene presented strong correlations to ${\Sigma}_{16}PAHs$. Principal component analysis discriminated entire samples into three groups by two principal components (PC1 and PC2) with 70% of data variations, in which industrial types were not of importance, but a dominance of certain PAHs. Samples in group-I, which is high PC1 and low PC2, were characterized by a dominance of 2-ring PAHs, and in group-II, PC1 and PC2 showed a linear relation, was dominant 4-ring PAHs. Group-III with low PC1 and high PC2 includes 17 samples showing a noticeably high contribution of 3-ring PAHs to ${\Sigma}_{16}PAHs$. This study provides concentrations of PAHs in industrial sludges collected from a wide variety of sources (six industrial types) and two seasons of sampling events, and the comparison of ${\Sigma}_{16}PAHs$ with other studies are also discussed.