• Journal of Korean Society of Water and Wastewater
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• v.31 no.5
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• pp.431-440
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• 2017

The small-scale sewage treatement system with $A^2/O$ process was applied to evaluate applicability for Mongolian sewage, It was designed to have 10 m3/d flowrate and installed in Ulaanbaatar, Mongolia. During over 6month operation BOD, COD, TN, TP removal efficiency were measured and operation condition was optimized. In addition, MLSS concentration its internal circulation rate and DO were adjusted properly. BOD, COD showed average 88 perecent of removal and TN and TP achieved 81 percent and 88 percent removal efficency, respectively. Maxium influent concentration of BOD, COD, TN and TP was 214 mg/L, 300 mg/L, 24.3 mg/L and 5 mg/L respectively, which were decreased to 4.1 mg/L, 5.6 mg/L, 1.3 mg/L and 0.15 mg/L by the test system. This study show possibility tham small-scale sewage treatment system could be a useful system for scattered sewage wastewater treatment.

• Journal of Environmental Health Sciences
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• v.28 no.1
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• pp.79-84
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• 2002

Entrapped media with cellulous triacetate in which activated sludge was applied to induce operating factors and sewage treatment on site. The results are summarized as follows; The treatment efficiency of entrapped media is 92%, 90% and 80% at the size of 5mm, 7mm, and 12mm, respectively. Also, treatment efficient rate was increased by the packed amount of media in less than 30 % packed, while in more than 40 % packed that was decreased. It takes 10 day to reach the steady states and it is less than the existing activated sludge method. The slopes of oxygen consumption rate are almost parallel both in the entrapped media and free sludge. When organic loading rate is less than 1.0 kg/m$^3$ㆍd on site, it is achieved good removal rate independent of changes of loading rate.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.4
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• pp.519-526
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• 2006

In this study, the major operating factors in SND(simultaneous nitrification and denitrification) using bioreactor packed with submerged cilia media and granular sulfur such as variation of nitrification rate, organic matter removal efficiency and denitrification efficiency in different DO concentration were mainly evaluated. Synthetic wastewater and actual sewage were used as influent wastewater. Experiment with synthetic wastewater as influent wastewater was divided into three phases with the adjustment of DO concentration. As the results, nitrification efficiency and T-N removal efficiency in the Phase 3(DO 1.0~2.0 mg/L) were 99% and 52.3%, which is significantly greater than those in other two phases. Also, loading rate and denitrification efficiency of SCPGS(Submerged Cilia media Packed with Granular Sulfur) were calculated as $0.44kg\;NO_3^--N/m^3-day$ and 50%, respectively. On the other hand, nitrification rate was decreased from 99% to 64% according to the DO concentration with the variation from 3.0~3.5 mg/L(phase1) to 0.4~0.6mg/L(phase2). Although the nitrification rate was decreased in 64% according to the variation of the DO concentration, T-N removal rate was rapidly increased to 49% by increasing of the denitrification efficiency. Experiment with actual sewage as influent wastewater was carried out to evaluate efficiency of SCPGS in real operation condition of full-scale sewage water treatment plant. At the time, T-N removal rate in this experiment and full-scale wastewater treatment plants were given by 43% and 20%, respectively. The above results indicate that SCPGS can be used as an advanced treatment process for economical efficiency considered.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.3
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• pp.373-382
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• 2013

In this study, a biological odor treatment system was proposed to remove odor(foul smell) materials causing several problems in the closed sewage treatment plant. This odor treatment system was composed of a two-step biofilter system in one reactor. The two-step biofilter reactor was constructed with natural purification layer in upper part and artificial purification layer in lower part. The reed grasses of water purification plants were planted in the surface area and mixed porous ceramic media were filled with the lower part of biofilter reactor. By using the above experimental apparatus, the ammonia gas removal efficiency was attained to 98.3 % and the hydrogen sulfide gas removal efficiency was appeared more than 97.7 % which shows more effective than the conventional odor removal process.

• Journal of Korean Society on Water Environment
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• v.27 no.4
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• pp.523-532
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• 2011

In this study, from 2004 to 2008 influents and discharging effluents from 241 municipal public sewage treatment plants were surveyed. Statistics including average, Coefficient of Variation (CV) and Coefficient of Reliability (COR) for each season, time series analysis for removal efficiency and water quality of effluents, and a comparison of the effluent standards in Korea and other countries were presented. The average concentrations of TN and TP in influents. during winter season were 32.6 and 3.78 mg/L and during other season were 30.8 and 3.61 mg/L in 2008, respectively. The average TN concentration on the basis of the maximum monthly concentrations in the effluents during winter season ranged from 14.2~17.4 mg/L and during other season ranged from 12.2~14.8 mg/L. The TP concentration in the effluents depending on the each season was no big difference. TN removal efficiency decreased from Jan. to Feb. and TP removal efficiency decreased in Jan., Jun and July. Maximum COR during winter season were 0.61 but the COR for TN and TP during other season ranged from 0.96~1.48 and 1.09~1.81, respectively, due to big difference in the standard for TN and TP in effluents depending on the season. TN and TP standards for effluent of sewage treatment during winter season in Korea was much higher than those in other countries. Therefore the lower effluent standards during winter season is essential for the water quality improvement.

• Journal of Wetlands Research
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• v.15 no.4
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• pp.453-460
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• 2013

Rural area sewage distribution rate is 40 % less than urban area. Previous research results announced that one of the reason in water resource pollution was caused of low rural area sewage distribution rate. Analysis on operation result of 11 RCSTP in Bong-hwa area which is located at the upper region of An-dong Dam and Im-ha Dam. Based on operation result, an analysis on characteristics of wastewater in Bong-hwa and treatment efficiency of installed treatment process was conducted. The wastewater influent of Bong-hwa contained high organic matter and nutrient than those of urban area. Treatment process showed totally stable treatment efficiency. But, The treatment efficiency for nutrient showed high fluctuation. This result means which is need to operation condition control of nutrient treatment when operating RCSTP.

• Korean Journal of Environmental Agriculture
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• v.27 no.1
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• pp.44-49
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• 2008

The purpose of this study is to investigate the current status, including the maintenance problems and removal efficiency, of small sewage treatment facilities in Chung-nam province(Asan, Buyeo, and Gongju city). Our results showed that inflow water quality of Asan city was 19.1 mg/L of BOD, 29.0 mg/L of COD, 13.4 mg/L of T-N and 1.5 mg/L of T-P, respectively, which was much higher than any other site. Among the factors known to be an important index of water quality, the SS and BOD removal efficiency was about 70% and 50% respectively. However, the nitrogen removal efficiency was less than 10%. The total removal efficiency of pollutant was 71.1% of SS, 52.6% of BOD, 46.2% of COD, 9.2% of T-P and 4.6% of T-N respectively. Therefore nitrogen removal processes are required to prevent serious eutrophication of small river. Removal efficiency for BOD and SS of high-efficient sewage treatment facilities (STFs) and contact oxidation process was much higher than another process. Performance of these sewage treatment facilities(STFs) is not optimal due to ineffective planning for the inflow water quality. To improve these facilities, it is proposed that a technical expert analysis of water quality at these facilities is periodically required.

• KSBB Journal
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• v.24 no.3
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• pp.291-295
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• 2009

This study performed verification experiment for the removal of total nitrogen in sewage from a Town M village sewage treatment plant using YPNR processes. The total nitrogen discharged after the denitrification process was maintained at a level of 8-15 mg/L, which results in the total nitrogen removal efficiency above 68% on average. The total nitrogen components in discharged water consisted of 16% of ammonia nitrogen, 6% of nitrite nitrogen, and 77% of nitrate nitrogen, which reaches a 95% nitrification efficiency. Hence, the YPNR advanced treatment process used in this study can be successfully applied to sewage treatment.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.3
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• pp.52-59
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• 2012

As the result of reviewing the linked treatment of water quality for treating process at public livestock wastewater treatment facilities for fair selection of the proper linked process in case of linking sewage treatment plant for livestock wastewater, in case of wastewater processed by bio-reactor that is only biologically-treated, the load factor showed relatively high as 1.67%(base on design quality), 2.59%(base on operation quality) regarding COD and 3.69%(base on design quality), 7.67%(base on operation quality) regarding $COD_{Mn}$ but it is judged that there is nearly no influence on the operation of sewage treatment plan. And, in case of oxidized flotation-treated water & biofiltlation-treated water that are the advanced wastewater treatment, the load factor is approximately 1% and there is concern about the installation of excessive facilities in case of installing the advanced wastewater treatment. So, in case of considering the economic efficiency & stable operation of sewage treatment plant S, it is judged to be desirable to link with wastewater processed by bio-reactor that is biologically-treated.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.53-59
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• 2018

Water pollution is drastically increasing day by day, because of the enhancement in use of livestock, urban sewage detergents and fertilizers. Moreover increase in concentration of phosphorous and nitrogen contained in sewage, leads to green tide problem in the rivers and causes marine pollution. For this problem to solve, several technologies are being researched and developed. Among them, this experiment is a study on Bench-scale STP based on internationally certified sewage treatment equipment by MEPC. 227(64) of IMO. The purpose of this study is to compare the biological treatment efficiency of phosphorus of Bench-scale STP. The ratio of C : N : P was set to 10 : 5 : 3 and 10 : 3 : 1 as the operating conditions. And the operation cycle was set to anoxic(mixed) 70 min - aeration 50 min (70-50), anoxic(mixed) 90 min - aeration 60 min (90-60). As a result, the phosphorous treatment efficiency was 88% at average, and the treatment efficiency was steady at 90-60 better than 70-50. The efficiency of the bench-scale STP has been verified through this experiment and additional experiments are required to derive the optimal operating conditions.