• Proceedings of the Membrane Society of Korea Conference
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• 1998.06a
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• pp.95-112
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• 1998

Water quality in the public water course has been polluted more seriously than ever before due to the increase of the number and aremount of pollution sources such as domestic and industrial wastewater. For water quality conservation, the Korean government has been trying to construct sewage treatment facilities continually, of which treatment capacity reached to 11,452,400m$^{3}$/day in 1996. Night soil treatment facilites of m nationwide have the treatment capacity of 24,038m$^{3}$/day. But water quality has not been improved because the sewer systems were insufficient and the treatment efficiencies of sewage were not high, enough. For renovation of water quality, miscellaneous domestic wastewater must be treated because 27g BOD/day out of total 40g BOD/person-day come from miscellaneous wastewater, comparing to 13g BOD/day from night soil. However, sole treatment purifier treat only night soil from the flushing toilet. Therefore, it may be desirable to treat the miscellaneous domestic wastewater and the night soil from flushing toilet together by joint treatment purifier system as on-site domestic wastewater treatment technology. In Korea, the joint treatment purifier system, introduced in 1997, have the benefit as follows; i) good water poiluion control effect, ii ) good effect on river water flow, iii) water pollution control with sewage treatment facility, and iv) rapid pollution control effect, etc. In order to achieve a good effect as stated before, i ) strengthening effluent guideline including BOD, nitrogen and phosphorus, ii ) specializing operation to maintain high performance, and iii) supporting its construction and maintenance costs by the governmental level may be necessary: In addition, automation system of joint treatment purifier, technology for its package and compactness, and a new bio-media bio-filter with higher capacity should be further developed in agreement with a more stringent effluent guideline.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.115-121
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• 2006

The purpose of this study was to investigate applicability of pretreatment on the existing biological treatment for domestic wastewater reclamation. From Jar Tests, it was found that optimum dosage of coagulant was PAC 0.5mg/L and $FeCl_3$ 180mg/L for urban sewage. In this study, PAC 0.5mg/L was selected considering sludge production and the amount of coagulant required. In a continuous experiment performed with combining chemical coagulation and biological treatment, a considerable removal efficency was obtained in term of BOD, SS, T-N, T-P and ABS. When the raw sewage was supplied into the pre-chamical treatment facility, the removal of BOD and SS was 48.3% and 81.1%. However T-N removal was very low which means T-N consists of $NH_3-N$ mostly. T-P was almost completely recluced by the chemical addition. The effluent BOD & SS was 57~76 and 21~43mg/L, which could reduce the size of biological treatment facility. From the cost estimation pre-chemical treatment could save around half of the area required for biological treatment with post ceagulation.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.6
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• pp.663-671
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• 2016

Coagulation/precipitation process has been widely used for the removal of phosphate within domestic wastewater. Although Fe and Al are typical coagulants used for phosphate removal, these have some shortages such as color problem and low sedimentation velocity. In this study, both Fe and Al were used to overcome the shortages caused by using single one, and anionic polymer coagulant was additionally used to enhance sedimentation velocity of the precipitate formed. Batch experiments using a jar test were conducted with real wastewater, which was an effluent of the second sedimentation tank in domestic wastewater treatment plant. Response Surface Methodology was used to examine the responsibility of each parameter on phosphate removal as well as to optimize the dosage of the three coagulants. Economic analysis was also done on the basis of selling prices of the coagulants in the field. Phosphate removal efficiency of Fe(III) was 30% higher than those of Fe(II). Considering chemical price, optimum dosage for achieving residual phosphate concentration below 0.2 mg/L were determined to be 18.14 mg/L of Fe(III), 2.60 mg/L of Al, and 1.64 mg/L of polymer coagulant.

• Environmental Engineering Research
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• v.25 no.2
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• pp.243-250
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• 2020

A down-flow hanging sponge (DHS) bioreactor was operated for the treatment of domestic wastewater. The Stover-Kincannon model was applied for kinetic evaluation of the reactor performance during the operational period. As a result, the coefficient of determination (R²) for straight lines of effluent concentration from the experimental data and from the predictive data of BOD₅; NH₄⁺-N; and TN were 0.9727; 0.9883; and 0.9934, respectively. The calculation of saturation value constant (Umax - g L^-1 d^-1) and maximum utilization rate constant (KB - g L-1 d-1) were 56.818 and 75.034 for BOD₅; 2.960 and 4.713 for NH₄⁺-N; 2.810 and 8.37 for TN, respectively. The study suggests that Stover-Kincannon model can be used for effective evaluation of kinetic removal of BOD₅; NH₄⁺-N; and TN from domestic wastewater treated in a DHS bioreactor.

• Journal of Navigation and Port Research
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• v.29 no.9
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• pp.783-788
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• 2005

This study provided the status and efficiency of the domestic wastewater sea outfalls based on the previous numerical and experimental studies for the analysis of the buoyant discharges from Rosette diffuser in shallow water. The VISJET model and the hybrid model proposed by Kim (2002) can be proper models for the domestic sea outfalls. The experimental results show that the merging height for MBR and MIR depends on the riser diameter and spacing between risers, and the bending characteristics of the buoyant discharges in still ambient water have significant impacts on the dilution. The current wastewater outfall systems in Korea are not effective for the environmental aspect due to the low discharge water depth. The strategies to reduce the contamination near the domestic wastewater outfalls were found to require the sufficient discharge water depth, proper diffuser location considering the tidal currents, enough riser diameter, and sufficient spacing between risers.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.2
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• pp.289-294
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• 2006

A pilot scale non-woven fabric filter separation activated sludge system was investigated for practical application on domestic wastewater reclamation and reuse. The system was operated in A/O (Anaerobic/Oxic) process with submerged filter module in the aerobic compartment. In the test of two types of filter materials ($70g/m^2$ and $35g/m^2$), the initial flux (0.42m/d) could be maintained for about three months by regular air backwashing of $70g/m^2$ filter at 0.3m water head. The removal efficiency of organic matter by the system was BOD 93.3%, CODcr 96.3%, SS 96.7%. The effluent quality was 7.8mg/L, 12mg/L and 5mg/L for BOD, CODcr and SS, respectively. The water quality was enough to meet a standard for domestic reuse without human contact. T-N removal efficiency was 49.9% at internal recycle rate 2Q and C/N ratio 3.3. The removal efficiency of T-P was 50% with average effluent concentration, 2.6mg/L.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.4
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• pp.475-485
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• 2006

• Journal of Korean Society of Water and Wastewater
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• v.23 no.2
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• pp.231-239
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• 2009

The purpose of this research is to provide more reliable water unit factors of domestic airports by investigating of general informations related to the domestic airport. The informations of domestic airports such as passengers, settled population of airports, building areas and water amount are investigated to estimate the unit factor of water of domestic airports. The domestic airports are divided into three type such as central airport, position airport and general airport. Through analysis of relationship between water amount and the others, the unit factor of water could be calculated. The water amount of central airport as Incheon international airport and position airports could be estimated by unit factor of settled population. The others could be estimated by unit factor of building area.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.3
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• pp.41-47
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• 1998

Doam Lake is located around the pasture area and Yongpyung Resort. Because of the waste load of domestic animals, nutrient concentration of the stream is high. In this study, waste load of Doam Lake watershed is calculated, and QUAL2E model is applied to the upper part of the Songcheon to calculate the input boundary concentration of Doam Lake. And WASP5 model is applied for the water quality modeling of Doam lake. The results indicate that advanced treatment of domestic animal wastes is necessary for the lake water quality management.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.3
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• pp.217-223
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• 2000

This study is to investigate the effect on the mount of domestic water use by the water pressure and the number of a family for the each house. Tow apartment sites which had elevated water tanks on the roof were selected as the reserch area. Tow techniques such as Analysis of Variance(ANOVA) and Analysis of Correlation were used for the analysis.