• 한국환경보건학회지
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• 제46권2호
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• pp.170-183
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• 2020

Objectives: This study was conducted to estimate a technology to reduce hydrogen sulfide (H₂S) in sewage odor using microbial deodorant. Methods: After injecting five commercially available microbial deodorants into fresh sewage, the concentration of hydrogen sulfide over time was measured using the headspace method. H₂S concentration in odor samples was measured using gas chromatograph/FPD. Calculated odor concentration and calculated odor intensity by H₂S concentration remaining after treatment with microbial deodorant were evaluated theoretically. Results: The rate of H₂S abatement by microbial deodorant differed depending on the experimental conditions and the type of deodorant, but it was found to range from 63 to 82%. Especially, two deodorants showed high H₂S reduction rates of over 80% on average. However, based on the best deodorant, the theoretically calculated odor concentration by H₂S after microbial deodorant treatment was 4,400 OU_k, and the theoretical odor intensity was also rated at 4 degrees or higher. Conclusions: In conclusion, microbial deodorant is considered to have a relatively high effect on reducing H₂S in sewage odor. However, even after treatment with microbial deodorant, calculated odor concentration and calculated odor intensity were relatively high. This is thought to be caused by other odorous substances besides H₂S.

• 한국환경생태학회:학술대회논문집
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• 한국환경생태학회 2003년도 추계학술논문발표회 논문집
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• pp.105-126
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• 2003

In Korea most of annual rainfall is concentrated in several episodic heavy rains during the season of summer monsoon and typhoon. Because of uneven rainfall distribution many dams have been constructed in order to secure water supply in dry seasons. The Han River system has the most dams among Korean rivers, and the river is a series of dams now. Reservoirs need different strategy of water quality control from river water. Autochthonous organic matter and phosphorus should be the major target to be controlled in lakes. In this Paper some problems are discussed that makes efforts of water quality improvement ineffective in lakes of Korea, even after the substantial investment to wastewater treatment facilities.1) Phosphorus is the key factor controlling eutrophication of lakes and the reduction ofphosphors should be the major target of water treatment. However, water quality management strategy in Korea is still stream-oriented, and focused on BOD removal from sewage. Phosphorus removal efficiency remains as low as 10-30%, because biological treatment is adopted for both secondary treatment and advanced treatment. The standard for TP concentration of the sewage treatment plant effluent is 6 mgP/l in most of regions, and 2 mg/l in enforced region near metropolitan water intake point. TP in the effluents of sewage treatment plants are usually 1-2 mg/1, and most of plants meet the effluent regulation without a further phosphorus removal process. The generous TP standard for effluents discourages further efforts to improve phosphorus removal efficiency of sewage treatment. Considering that TP standard for the effluent is below 0.1 mg/l in some countries, it should be amended to below 0.1 mg/l in Korea, especially in the watershed of large lakes.2) Urban runoff and combined sewer overflow are not treated, even though their total loading into lakes can be comparable to municipal sewage discharges on dry days. Chemical coagulation and rapid settling might be the solution to urban runoff in regard of intermittent operation on only rainy days.3) Aggregated precipitation in Korea that is concentrated on several episodic heavyrains per year causes a large amount of nonpoint source pollution loading into lakes. It makes the treatment of nonpoint source discharge by methods of other countries of even rain pattern, such as retention pond or artificial wetland, impractical in Korea.4) The application rate of fertilizers in Korea is ten times as high as the average ofOECD countries. The total manure discharge from animal farming is thought to be over the capacity of soil treatment in Korea. Even though large portion of manure is composted for organic fertilizer, a lot of nutrients and organic matter emanates from organic compost. The reduction of application rate and discharge rate of phosphorus from agricultural fields should be encouraged by incentives and regulations.5) There is a lot of vegetable fields with high slopes in the upstream region of the HanRiver. Soil erosion is severe due to high slopes, and fertilizer is discharged in the form of adsorbed phosphorus on clay surface. The reduction of soil erosion in the upland area should be the major preventive policy for eutrophication. Uplands of high slope must be recovered to forest, and eroded gullies should be reformed into grass-buffered natural streams which are wider and resistant to bank erosion.

• 한국물환경학회지
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• 제29권2호
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• pp.276-287
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• 2013

Domestic sewage contains increasingly more pharmaceuticals and personal care products (PPCPs), due to rising use of medicines, health supplement food and daily necessities. And various types of industrial wastewater from pollution sources in treatment areas could flow into the public sewerage treatment plants (PSTPs) in metropolitan areas. The conventional PSTPs are designed to treat suspended solids, biodegradable organics, nitrogen and phosphorous from residential and industrial areas and public facilities. However, toxic, conventional, and non-coventional pollutants from non-domestic sources that discharge into sewer system as well as domestic source with various chemicals could not be treated in the conventional PSTPs and discharged untreated to public basin. In this paper we aim to consider the establishment system of effluent standard of PSTPs in comparison with water quality standard of water environment and wastewater discharge regulation. And also we suggest the necessity of regulations on the pretreatment of industrial wastewater as part of efforts to improve water quality in sewerage systems and to protect public basin.

• 상하수도학회지
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• 제24권2호
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• pp.173-181
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• 2010

This study was conducted to investigate the possible installation of small hydro-power plant at the discharge point of Gumi sewage treatment plant (STP) using treated wastewater. Sufficient amount of water to transfer to electric power and the selection of proper location are two essential elements for the construction of small hydro-power facility. Preliminary analysis based on site visit and existing data in Gumi STP were made. Capacity of the small hydro-power plants and exact location were determined by geomorphological condition and flow duration characteristics. Flow duration characteristics and its duration curve were identified using monthly rainfall data in Gumi STP. Relevant facts of small hydro-power system in other STP were referred to adopt to Gumi STP situation. Flowrate of treated effluents and effective head between flow chamber and the location of hydraulic turbine in Gumi STP are found to be $3.70m^3$/sec and 3.5m respectively. Electric generation rate based on this feasibility study was estimated to be 86.3kW/h. Yearly electric generation rate was expected to be 932.4MMh. Proposed small hydro-power plant construction in Gumi STP is to be reasonable.

• 상하수도학회지
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• 제32권4호
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• pp.337-348
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• 2018

As the issue of microplastics (MPs) detection in tap water was raised in other countries in 2017, monitoring of MPs in drinking and source water, and sewage treatment plant (STP) effluents was initiated. This study intends to look into other studies on MPs in STPs at home and abroad, and review the characteristics of MPs and their removal efficiencies in the STPs, the risk and effect of MPs on watersheds, and management practices in order to help better understand MPs in STPs. To manage MPs effectively in STPs, it is necessary to investigate the detection of MPs discharged from STPs, do research on human health risk and control measures, and build a monitoring system including standardized analytical methods.

• 한국환경보건학회지
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• 제28권2호
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• pp.61-69
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• 2002

Oship stream is located nearby south eastern coasts. This study was performed to find out waters quality modeling and then to predict water quality of Oship stream. Based on survey data, BOD, T-N, T-P calibration and verification result were in good agreement with measured value within mean coefficient variance(MSE) value, which were 13.9%, 9.0%, 26.5% and 19.5%, 12.0%, 16.5%, respectively. Sectional water quality predictions of the main stream of Oship stream are executed on the basis of the following cases 1) with sewage treatment of Dogye-eup 2) reduction of mine wastewater treatment of 80% in th basin. As a result, BOD, T-P improvement rates at down stream of Oship stream, case 1) were appeared 12.2%, 22.2%, case 2) maximum sulfate ion and conductivity reduction removal rate of Oship stream were 58%, 68%. The main pollution sources of Oship-stream were almost domestic wastewater and mine wastewater discharged from Dogye-eup which located in uppers stream. The large effects will appear after the construction of Dogye sewage water treatment plant which remove the organic matter and nutrients in these sewage water. The waste water from mine can not easily to treat for characteristics of effluence and economic problems. However, to achieve the goal of water quality in Oship-stream water system, treatments of those are necessary.

• 산업기술연구
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• 제31권A호
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• pp.135-145
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• 2011

This study was conducted to analyze the cost effectiveness in line with total phosphorus standard enforcement of public sewage treatment facilities. The additional cost for the total phosphorus removal process was calculated to analyze the cost effectiveness of the advanced water purification process. The analysis results showed that the T-P removal by coagulation sedimentation was more efficient than the advanced water purification facilities in terms of facilities investment cost, and if the coagulation filteration was used for T-P removal, the activated carbon process among the advanced water purification techniques was more efficient in terms of facilities investment cost. In this study, the effects of the T-P removal process that will be additionally introduced according to the tightening of the effluent T-P standard were analyzed within a limit. The actual benefits of improved T-P concentration in the water source will provide diverse values, including the leisure water, environment improvement water, eco-system in the water source and industrial water, in addition to the advanced water purification.

• 한국산학기술학회논문지
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• 제10권10호
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• pp.2803-2809
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• 2009

국내 건설업계는 자체 엔지니어링 기술 확보 및 높은 수준의 건설사업 관리기술의 보유와 더불어 사업초기 단계에서 해당 프로젝트의 경제적 타당성 평가를 수행할 수 있는 능력이 절실히 요구되어진다. 시설물의 설계 및 시공 기술은 최근의 국제 시장에서 수주를 위해서는 반드시 필요한 부분이며 수익을 창출할 수 있는 사업수행을 위해서는 사업초기단계부터 사후유지관리까지의 연속적인 건설사업 관리기술이 요구되어진다. 건설사업 관리기술은 프로젝트 시작단계에서부터 운영 유지관리 단계까지 단계별로 발생하는 비용에 대해 얼마나 경제적이고 효율적으로 관리하느냐에 따라 프로젝트의 성공여부를 결정짓는 역할을 한다. 이러한 단계별 비용항목의 체계적인 분석을 위해 본 연구에서는 국내 하수처리장을 대상으로 프로젝트 전반에 걸친 비용흐름 및 요소를 조사하였다. 특히 국내 하수처리시설의 유지관리비 DB를 조사하여 데이터 모델링을 수행하였고, 실적 DB의 불확실성을 고려하여 불확실성 해소를 위해 몬테카를로 시뮬레이션 방법을 이용하여 타당성 평가를 위한 평가 목적별(처리공법, 운영 주체 등) 유지관리비 예측 추세선을 제시하고자 하였다.

• 상하수도학회지
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• 제23권5호
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• pp.557-564
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• 2009

A combined sewer system can quickly drain both storm water and sewage, improve the living environment and resolve flood measures. A combined sewer system is much superior to separate sewer system in reduction of the non-point source pollutant load. However, during rainfall. it is impossible in time, space and economic terms to cope with the entire volume of storm water. A sewage system that exceeds the capacity of the sewer facilities drain into the river mixed with storm-water. In addition, high concentration of CSOs by first-flush increase pollution load and reduce treatment efficiency in sewage treatment plant. The aim of this study was to develope a processing unit for the removal of high CSOs concentrations in relation to water quality during rainfall events in a combined sewer. The most suitable operational design for processing facilities under various conditions was also determined. With a designed discharge of 19.89 m/min, the removal efficiency was good, without excessive overflow, but it was less effective in relation to underflow, and decreased with decreasing particle size and specific gravity. It was necessary to lessen radius of vortex separator for increasing inlet velocity in optimum range for efficient performance, and removal efficiency was considered to high because of rotation increases through enlargement of comparing height of vortex separator in diameter. By distribution of influent particle size, the actual turbulent flow and experimental results was a little different from the theoretical removal efficiency due to turbulent effect in device.

• 한국물환경학회지
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• 제27권6호
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• pp.877-884
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• 2011

In this paper, the removal characteristics of dissolved organic carbon (DOCs) by micro bubble ozonation process and $O_3/UV$ process were comparatively studied. In the point of DOC removing reaction coefficient, micro bubble ozonation system and $O_3/UV$ process had not significant difference, $0.0120sec^{-1}$ and $0.0141sec^{-1}$. Therefore micro bubble ozonation process is more suitable for tertiary treatment of sewage in the point of installation and maintenance cost-reducing. The optimum ozone injection rate was 2.0 g $O_3/g$ DOC and HRT was 3 min for the micro bubble ozonation process. The removal efficiency of DOC and SUVA in micro bubble ozonation system was 32.8% and 58.3% respective. Biological aerated filter (BAF) process was installed to remove soluble organic material increased by micro bubble ozonation system. And the effluent BOD of BAF was below 1.0 mg/L. In the view of cost-effectiveness, $O_3/BAF$ process was more profitable than $O_3/UV/BAF$ process for tertiary treatment of sewage. In order to nitrify ammonia in the BAF process completely, $NH_4{^+}-N$ concentration in the influent water of BAF should be designed considering low water temperature in the winter season.