• Journal of Korean Society of Water and Wastewater
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• v.7 no.1
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• pp.37-45
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• 1993

This research was performed to examined the applicability of a fixed-biofilm process for the wastewater treatment of military installations. Utilizing plastic net media, synthetic wastewater-average $BOD_5$ cocentration was $192mg/l$ treated in the three sets of reactors that have 8 hours, 6 hours, and 4 hours of hydraulic retention time. The results of this experiment showed that the biofilm was not detached easily, and the reactor was not closed by excess biomass. The average soluble $BOD_5$ concentrations of effluent were $6.0mg/l$ with 8 hours of retention time, $11.3mg/l$ with 6 hours of retention time, and $19.4mg/l$ with 4 hours of retention time. Especially it was reduced to $5.7mg/l$ in the second stage reactor with 4 hours of retention time. These resulted that the fixed-biofilm process could be adapted for the treatment of military installation wastewater.

• Korean Journal of Ecology and Environment
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• v.50 no.2
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• pp.187-194
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• 2017

This study was intended to evaluate the removal efficiency of nutrients in effluents of wastewater using microalgae. Microalgae used in the culture experiment collected in stream and reservoir located in Gyeongsangbuk-do. Dominant species in prior-culture tank were Monoraphidium contortum, Scenedesmus acutus, Coelastrum microporum and Chlorella sp. Dominant species in synthetic wastewater culture under the 4000 Lux and 8000 Lux were Chlorella sp. and Scenedesmus obliquus. The removal efficiency of $NO_3-N$ under the 4000 Lux and 8000 Lux were 27.2%~88.1% and 63.0%~83.6% respectively. The removal efficiency of $PO_4-P$ under the 4000 Lux and 8000 Lux showed above 93%. Removal efficiency of nutrients of $1.0{\times}10^6cells\;mL^{-1}$ inoculation concentration was more higher than that of nutrients of $1.0{\times}10^5cells\;mL^{-1}$ and $1.0{\times}10^7cells\;mL^{-1}$ inoculation concentration. Microalgae cultured in synthetic wastewater removed 94.9% of TN and 90.0% of TP. The removal rate of TN and TP in synthetic wastewater were $1.961mg\;L^{-1}\;day^{-1}$ and $0.200mg\;L^{-1}\;day^{-1}$ respectively. Nutrient removal efficiency of microalgae according to kinds of wastewater showed the highest in the private sewage.

• Journal of Environmental Science International
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• v.5 no.3
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• pp.361-367
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• 1996

An inverse fluidized-bed biofilm reactor (IFBBR) was used for the treatment of highly-emulsified oily wastewater. When the concentration of biomass which was cultivated in the synthetic wastewater reached to 6000 mg/1, the oily wastewater was employed to the reactor with a input COD concentration range of 50 mg/1 to 1900 mg/l. Virtually the IFBBR showed a high stability during the long operation period although soma fluctuation was observed. The COD removal efficiency was maintained over 9% under the condition that organic loading rate should be controlled under the value of 1.5 kgCOD/$m^3$/day, and F/M ratio is 1.0 kgCOD/kgVSS/day at $22{\circ}C$ and HRT of 12 hrs. As increasing organic loading rates, the biomass concentration was decreased steadily with decreasing of biofilm dry density rather than biofilm thickness. Based on the experimental jesuits, it was suggested that the decrease in biofilm dry density was caused by a loss of biomass inside the biofilm.

• Korean Journal of Microbiology
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• v.28 no.3
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• pp.243-248
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• 1990

Genetically engineered strains of Pseudomonas, which could degrade the various aromatic hydrocarbons, were acclimated to the synthetic wastewater with increasing substrate concentration. All of the tested strains except KUD101 showed 70-90% of the COD removal efficiencies. Acclimated strains, Pseudomonas putida KUD106, KUD107 and KUD108 were inoculated into the ordinary activated sludge and these sludges were used in the dyeing or alkylbenzene wastewater treatment system. In the case of the wastewater containing alkylbenzene compounds, COD removal efficiency was 12-14% higher than that of the ordinary activated sludge, while it was not effective for dyeing wastewater. On the other hand, the floc formation of the activated sludge inoculated with genetically engineered strains was more rapid in both wastewaters tested than that of the activated sludge by the ordinary natural strains.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.2
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• pp.231-236
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• 2010

A compressible media filtration process with synthetic fiber media was studied for combined sewer overflows (CSOs) treatment. Since the operation performance of fiber media filtration was dependent on the pattern of CSOs, the flow rate of CSOs was investigated and it was characterized by a big fluctuation. Thus, in this study, the fiber media filtration process was tested with wide range of filtration velocity. The removal efficiency was proportion to the increase in compressibility. As the filtration velocity was increased, the treatment efficiency was decreased and consequently leveled off when the velocity exceeded 750 $m^3/m^2$/d. An exponential equation was introduced to express the relationship between the removal efficiency and up-flow velocity. At columm test, six repetition of filtration and backwash cycle did not after the filtering velocity under the constant pressure condition.

• Environmental Engineering Research
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• v.20 no.2
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• pp.111-120
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• 2015

Contaminants of emerging concern (CECs) including endocrine disrupting compounds (EDCs) and pharmaceuticals and personal care product chemicals (PPCPs) have recently received more attention because of their occurrence in water bodies and harmful impacts on human health and aquatic organisms. Triclosan is widely used as a synthetic broad-spectrum antimicrobial agent due to its antimicrobial efficacy. However, triclosan detected in aquatic environment has been recently considered as one of CECs, because of the potential for endocrine disruption, the formation of toxic by-products and the development of cross-resistance to antibiotics in aquatic environment. This comprehensive review focuses on the regulations, toxicology, fate and transport, occurrence and removal efficiency of triclosan. Overall, this review aims to provide better understanding of triclosan and insight into application of biological treatment process as an efficient method for triclosan removal.

• Journal of Korean Society on Water Environment
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• v.16 no.4
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• pp.555-563
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• 2000

The study was conducted to evaluate the adsorption equilibrium of heavy metals on bone charcoal made of livestock bone which was sintered at $550{\sim}600^{\circ}C$. Analysis of bone charcoal by XRD and FT-IR showed that crystal structure was similar to that of synthetic hydroxyapatite. Adsorption equilibrium capacity of single component (Pb, Cd, and Zn) on bone charcoal could be expressed as Langmuir, Freundlich, and Sips equations. Sips isotherm was best among the three isotherms. The values predicted by IAST(ideal adsorbed solution theory) showed good relationship to the experimental data in multicomponent adsorption equilibrium. Adsorption affinity was in order of Pb, Cd, and Zn. The order was same in case of activated carbon or synthetic hydroxyapatite. Through the study results. it would be expected that bone charcoal made of livestock could be used in field of wastewater treatment plants as adsorbent to remove heavy metal.

• Journal of Environmental Science International
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• v.7 no.2
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• pp.209-216
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• 1998

Nanofiltration[NF45] and reverse osmosis membrane(HR98PP) separation treatment of dyestuff wastewater was carried out In order to separate relatively pure water from synthetic dyestuff wastewater, which consists of reactive dye, acid dye, basic dye, direct dye, and disperse dye. The experiments were performed by using the plate and frame membrane module. In the nanofiltration and reverse osmosis membrane separation, When the NaCl concentration was 0.1, 5.0, and 20.091, retention was 63.0, 46.0, 0.9%, respectively. When permeate flux was 125.0, 67.5, and 45.0 L/$m^2$ h, the osmotic pressure increased with Increasing the NaCl concentration. Permeate flux of two membranes Increased as temperature Increased due to segmental movement of polymer of the membrane and the rejection rate of dyestuff was decreased gradually. It was found that the rejection rate was about 95% in the nanofiltratlon, while the reverse osmosis membrane showed a high rejection rate of 99% under all temperature and pressures conditions.

• Advances in environmental research
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• v.9 no.2
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• pp.85-95
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• 2020

In this study, the decolorization of Evercion Blue P-GR (EBP) and Ostazin Black H-GRN (OBH) was investigated using white-rot fungi named as Trametes versicolor (T. versicolor) by Membrane Bioreactor (MBR) system. This study involved experiments employing synthetic textile wastewater in Membrane Bioreactor (MBR) system (170 ml), initially inoculated with a pure culture of fungi, but operated, other than controlling pH (4.5±0.2) and temperature (25±1℃), under non-sterile conditions. The effect of dye concentrations on fungal biodegradation was also investigated. The decolorization efficiencies were 98%, 90%, and 87% respectively, for EBP when the initial dye concentration of 50, 100, and 200 mg L^-1 were used. However, the decolorization percentages for OBH dye were obtained 95% for 50 mg L^-1 dye solution in 2 days and 66% for 100 mg L^-1 dye solution in 5 days. Possible interactions between dye molecules and the fungal surface were confirmed by SEM, EDX, and FTIR analyses.

• Journal of the Korean Society of Combustion
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• v.18 no.2
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• pp.17-22
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• 2013

In this study, we tested the absorption of $CO_2$ in combustion gas into an alkaline wastewater to simultaneously control $CO_2$ and wastewater. During the experiment, we investigated the effects of operating parameters on neutralization characteristics of the wastewater by using $CO_2$ in a bench-scale semi-batch jet loop reactor (0.1 m diameter and 1.0 m in height). The operating parameters investigated in the study are gas flow rate of 1.0-2.0 L/min, liquid recirculation flow rate of 4-32 L/min, and liquid temperature of $20-25^{\circ}C$. It was shown that the initial pH of wastewater rapidly decreased with increased gas flow rate for a given liquid recirculation flow rate. This was due to the increase in the gas holdup and the interfacial area at higher gas flow rate in the reactor. At constant gas flow rate, the time required to neutralize the wastewater initial pH of 10.1 decreased with liquid recirculation flow rate ($Q_L$), reached a minimum value in the range of $Q_L$ = 16-24 L/min, and then increased with further increase in $Q_L$. Further, the time required to neutralize the wastewater was shortened at higher temperatures.