• Journal of environmental and Sanitary engineering
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• v.3 no.1 s.4
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• pp.27-39
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• 1988

This investigation was carried out to evaluate the removal effect of biological contaminants for the municipal sewage treatment process at Cheonggye Cheon terminal plant which in the first plant for municipal sewage treatment in Seoul area. It was conducted in raw influent, primary treatment water and secondary treatment water from September, 1986 to July, 1987. The results were as follow; 1, The primary treatment could eliminate microbials for $65.38\%$ of total bacteria, $64.35\%$ of total coliform, $62.16\%$ of fecal coliform $69.48\%$ of pseudomonas and $64.70\%$ of fecal streptococci in averages for a year respectively. 2. The secondary treatment could eliminate microbials for $97.50\%$ of total bacteria, $97.30\%$of total coliform, $95.95\%$ of fecal coliform, $97.00\%$ of pseudomonas and $96.53\%$ of fecal streptococci in average for a year respectively. 3. In the detect rate of pathogenic agent, salmonella spp was decreased $12.5\%$ to $4.2\%$ in primary treatment and it was not detected in secondary treatment, shigella spp was detected $4.2\%$ in influent water but it was not detected in primary and secondary treatment. 4. In the seasonal variation of treatment effect, the removal of summer was the highest, and the removal of all item in winter was lower than the other seasons. 5. There was significant correlation between water temperature and microbal all items (P<0.05) $NH_3-N$ and Microbal items (P< 0.01) at raw water.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.4
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• pp.96-105
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• 2000

Field experiment was performed from August 1996 to December 1999 to examine the performance of constructed wetland system for wastewater treatment in rural area. The constructed wetland system was installed in Konkuk University and the effluent from septic tank of school building was used as an influent to the treatment basin. The treatment basin was composed of sand bed with planted reed. From August 1996 to June 1998 the hydraulic loading rate was fixed with about 15.63cm/day and theoretical detention time was 1.38 days, and from July 1998 to December 1999 the hydraulic loading rate was about 6.25cm/day and theoretical detention time was 3.5days. It worked continuously even during winter time, and the sewage flowed without freezing even when average daily air temperature was below -1$0^{\circ}C$. Average removal rate of BOD , COD, and SS was about 70%, T-P removal rate was about 50.8% , and T-N removal rate was 23.9%. The reason for poor T-N removal might be due to high influent concentration and short retention times. At the later years BOD and COD removal rates were increased , and SS and T-P removal rates did not change significantly , but T-N removal rates were decreased. The effluent of the wetland system often effluent water quality standards for sewage treatment plant, therefore, further treatment would be required if the effluent need to be discharged to the public water. Wetland system involves relatively large land area and could be suitable for rural area. Therefore, utilization of reclaimed sewage for agricultural purpose or subsequent land treatment is recommended as a ultimate disposal of sewage for agricultural purpose or subsequent land treatment is recommended as a ultimate disposal of sewage in rural area.

• Journal of Korean Society of Disaster and Security
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• v.12 no.2
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• pp.25-34
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• 2019

The efficiency of sewage treatment was analyzed by statistical method based on the water quality and operation data of the sewage treatment plant applying the oxidation method. The obtained water quality data were pH, temperature, BOD, SS, T-N, ${NH_4}^+-N$, and T-P of influent and discharge water. Data analysis was performed by correlation analysis, ANOVA analysis, and cluster analysis. As a result of the statistical analysis, the influent flow rate in the sewage treatment plant was the highest in summer. The average inflow flow rate was $3.000m^3/s$. According to Box plot results, COD, and T-P concentrations of effluents were not significantly different from season to season. The Pearson correlation analysis showed strong positive correlation between BOD, COD, T-N, and T-P in influent flow. Seasonal BOD and T-N concentrations were highest in winter and COD and T-P in seasonal influences. BOD showed a strong negative correlation with the water temperature, but showed a positive correlation with other operating factors such as HRT, SRT and C/N. The higher the influent temperature, the lower the BOD concentration. Therefore, retention time was shortened and BOD treatment efficiency was lowered. It was found that T-N had a higher retention time and a higher concentration than DO concentration. On the other hand, T-P did not show a significant correlation with operating factors.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.674-681
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• 2009

Characteristics of organic matters (OM) in wastewater and the removal efficiencies were investigated using the influent and the effluent samples collected from 21 wastewater treatment plants. The OM characteristics investigated included biodegradability, humic content, specific UV absorbance (SUVA), the distribution percentage of refractory OM (R-OM), and synchronous fluorescence spectra. The types of wastewater (sewage, livestock waste/night soils, industrial waste) were easily distinguished by comparing the synchronous fluorescence spectra of the influent wastewater. The prominent peak of protein-like fluorescence (PLF) was observed for livestock waste/night soils whereas sewage exhibited a unique fluorescence peak at a wavelength of 370 nm. Irrespective of the wastewater types, the distribution percentage of R-OM increased from the influent to the effluent. Livestock waste/night soils showed the highest removal efficiency among all the three types of wastewater. There was no statistical difference of the removal efficiency between a traditional activated sludge and biological advanced treatment processes. Removal efficiency based on dissolved organic carbon DOC presented good correlations with the distribution percentage of R-OM and fulvic-like fluorescence (FLF) of the influent. The prediction for DOC removal efficiency was improved by using multiple regression analyses based on some selected OM characteristics and mixed liquid suspended solid (MLSS).

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.5
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• pp.65-77
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• 2014

The ecosystem of Jaemin stream, flowing into the center of Gongju-si, had been damaged by low water quality and lack of water quantity of the steam. However, after applying the SSB (Sustainable Structured wetland Biotop) system to the flood plain and the upstream of Jaemin stream, the efficiency of ecological water purification and ecological restoration are as follows. Through the constant maintenance and monitoring from year 2009 to year 2013 after restorative design and construction the average influent concentration of BOD5 was 4.2 mg/L, and the average effluent concentration was 1.8 mg/L, reaching ecological water purification rate of 57%. As for the T-N, the average influent concentration was 9.983 mg/L, and the average effluent concentration was 6.303 mg/L, showing the rate of 37%. For the T-P, the average influent concentration was 0.198 mg/L, and the average effluent concentration was 0.098 mg/L, being the rate of 51%. The vegetation of Jaemin stream monitored for 2 years after the restoration was composed of 51 species in 28 families which show high ratio of planted native species. As for the animals in the site, 5 species in 3 families of reptiles and amphibians, 34 species of 23 families of birds, and 3 species in 2 families of mammals were monitored, indicating that the bio-diversity of the site has improved, as well.

• Journal of Korean Society on Water Environment
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• v.16 no.4
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• pp.523-532
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• 2000

The purpose of this study was to investigate the effects of the hydraulic retention time (HRT) and organic loading rate (OLR) on microbial characteristics and treatment efficiency in sewage treatment using aerated submerged biological filter (ASBF) reactor. This reactor combines biodegradation of organic substrates by fixed biomass with a physical separation of biomass by filtration in a single reactor. Both simulated wastewater and domestic wastewater were used as feed solutions. The experimental conditions were a temperature of 17 to $27^{\circ}C$, a hydraulic retention time of 1 to 9hr, an organic loading rate of 0.47 to $3.84kg\;BOD/m^3{\cdot}day$ in ASBF reactor. This equipment could obtain a stable effluent quality in spite of high variation of influent loading rate. Total biomass concentration. biofilm thickness and biofilm mass increased an exponential function according to the increasing OLR. The relationships between water content and biofilm density were in inverse proportion. The percentage of backwash water to influent flow was almost 9%. The separation efficiency of biomass was the percentage of 91 to 92 in ASBF reactor. The sludge production rates in feed solutions of simulated wastewater and domestic wastewater were 0.14~0.26 kg VSS/kg BODrem, 0.43~0.48 kg VSS/kg BODrem, respectively.

• Journal of Korean Society on Water Environment
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• v.25 no.4
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• pp.553-559
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• 2009

Currently, small scale sewage works are getting increase in Chung Nam Province and it is strongly required for those plants to get the information of optimized procedures and technologies. Most processes for sewage works in Korea were designed for large scale plants, so many difficulties are observed in small scale sewage works. This study was conducted to evaluate the propriety of O&M and construction cost for sewage treatment plants in Chung Nam Province. The treatment results and process stability of 32 public sewage treatment plants were also investigated. It is expected to provide optimum O&M and construction cost for future small scale sewage works and improving projects of existing plants by these results. Pollution problems caused by small scale plants are usually restricted to small areas; however, in view of the high cost per unit population, treatment requirements and alternatives have to be studied carefully. In comparison to larger plants, more pronounced and different boundary conditions such as unstable influent load, per capita costs and a large variety of feasible treatment and disposal systems were considered.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.73-80
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• 2018

In this study, the solids removal characteristics using T-P sludge generated from PACl coagulation were analyzed by laboratory scale and full scale experiment. As the amounts of T-P sludge injection into the raw sewage influent increased at the rate of 0, 1, 2, 3, 4 %, the suspended solids concentrations after 20 minutes setting test decreased to 210, 137, 91, 64, 43 mg/L, respectively. The filtration time required for dewatering test of the raw sewage influent decreased to 982, 728, 658, 581, 492 sec for 0, 1, 2, 3, 4% of T-P sludge injection, respectively. As the amounts of PACl coagulant into the effluent from final setting tank increased at 0, 10, 20, 30, 40 mg/L, the required filtration times for T-P sludge increased into 12.3, 41.7, 53.7, 67.2, 79.5 sec and the dewaterability of T-P sludge decreased. After T-P sludge returned into the primary settling tank on J-si sewage treatment plants, the effluent concentrations of COD, SS, T-N and T-P from primary settling tank into bioreactor decreased by 35.9, 27.9, 22.2, and 52.6% due to the coagulation effects of the T-P sludge. Finally, it was found that the return of T-P sludge into the primary settling tank could result into the sludge reduction having a lower water content of 3.03% p than in case of the only T-P sludge dehydration.

• 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.

• Korean Journal of Ecology and Environment
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• v.57 no.1
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• pp.28-38
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• 2024

In this study, in order to analyze the water purification efficiency according to the influent water conditions of artificial wetlands, the purification efficiency was compared at two points where sewage treatment water flows in and one point where good effluent flows in. As a result of reviewing the results of the analysis of influent and effluent and the removal efficiency, the T-N and T-P removal efficiency was calculated at 54.7% and 77.4%, respectively, for the two points where sewage treatment water was treated, the treatment efficiency of SS 90.8%, BOD 51.1%, TOC 30.6%, T-N 38.8%, T-P 55.3% was shown. As a result, the efficiency of removing pollutants in the artificial wetland was found to be proportional to the concentration of influent water, and in order to create an efficient artificial wetland, it is judged that thorough review and management at the design stage are necessary considering that the removal efficiency of high-concentration contaminated water was high.