• 한국농공학회지
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• 제44권2호
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• pp.161-173
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• 2002

Recently, absorbent biofilters, which are inexpensive and easy to manacle, have been supplied to the rural areas, but have limitations in removing the nutrients effectively. Accordingly, as an alternative plan. natural zeolites were arranged in front or at the rear of the absorbent biofilters, and their removal efficiency for nitrogen and, ultimately, their applicability to the on-site wastewater treatment system were studied. Furthermore, the same experiments were carried out on artificial zeolites, made from coal ashes at National Honam Agricultural Experiment Station, to compare natural zeolites with artificial ones. Treated wastewater through the Absorbent Biofilter showed 22.6% nitrogen removal efficiency, while 64.6% was attained when natural Zeolites were placed in front of the absorbent biofilters (Zeolite-Aerobic process). As an addition, phosphorus was also efficiently removed. On the other hand, Aerobic-Zeolite process, which arranged natural zeolites at the rear of the biofilters, did not have significantly higher nitrogen removal as compared to the treatment using only the absorbent biofilters. Furthermore, upon regeneration of the natural zeolite, the ion exchange rate was fecund to increase over 10% as compared to before regeneration. Our results show that natural zeolites, applied to the on-site wastewater treatment system through the Zeolite-Aerobic process, not only increase the removal efficiency of nutrients, but, by choosing the appropriate regeneration time, can also be cast-effective. Artificial zeolites, on the other hand, though more efficient in removing nutrients, cannot be regenerated and, therefore, are not cost-effective.

• 한국습지학회지
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• 제2권1호
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• pp.59-67
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• 2000

The aim of this study is to identify the role of this natural treatment system, which consists of Oenanthe javanica and wasted concrete as bio-media. Therefore, it was designed to experiment water quality, BOD, SS, T-N, T-P to recognize the efficiency of treatment system with one biofilter tank using wasted concrete and vegetation bed using Oenanthe javanica. It was also designed to compare two different biofilter reactors, which are air lift and upflow methods. In the result, it was demonstrated that upflow method is more efficient system to control water quality of polluted streams. The vegetation bed using Oenanthe javanica has the treatment efficiency of 41 % (BOD), 52 % (COD), 60% (SS), 36 % (T-P), 70 % ($NH_4-N$). It was therefore proved that removal rates of nutrients are not so good except $NH_4-N$ concentration with nitrification.

• 한국환경복원기술학회지
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• 제5권4호
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• pp.31-38
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• 2002

The rate of sewage treatment in South Korea was 68% in the late 1999. Sewage treatment is mostly made near big cities such as Seoul and Busan, and it is little in rural areas. Wastewater from households goes to streams directly without treatment in rural areas and pollutes streams. It is necessary to improve the progress for treatment of nutrients such as N and P which cause eutrophication in streams and lakes, because sewage treatment system in South Korea focuses on treatment of basic organic matters. Therefore it will contribute to improve discharged water quality if small sewage treatment systems by aquatic plants and microbes are introduced to rural areas where are not connected to local sewage treatment facility. This experiment was conducted to find out the best way using aquatic plants and microbes to purify wastewater from households through individual sewage treatment system. Phragmites communis, Iris pseudoacorus, Acorus calamus var. angustatus, Typha orientalis and Oenanthe javanica were used for this experiment. BOD, COD, SS, T-N and T-P were analyzed following standard methods for wastewater. The result shows that wastewater was roughly purified through pebbles and sands, and highly purified through aquatic plants and microbes especially in T-N and T-P. Iris pseudoacorus is the most effective in reduction of COD and BOD level. This system will work even in winter when plants die because microbes will be still working.

• 상하수도학회지
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• 제27권3호
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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.

• 상하수도학회지
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• 제35권1호
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• pp.53-61
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• 2021

The quantified analysis of damages to wastewater treatment plants by natural disasters is essential to maintain the stability of wastewater treatment systems. However, studies on the quantified analysis of natural disaster effects on wastewater treatment systems are very rare. In this study, a total disaster index (DI) was developed to quantify the various damages to wastewater treatment systems from natural disasters using two statistical methods (i.e., AHP: analytic hierarchy process and PCA: principal component analysis). Typhoons, heavy rain, and earthquakes are considered as three major natural disasters for the development of the DI. A total of 15 input variables from public open-source data (e.g., statistical yearbook of wastewater treatment system, meteorological data and financial status in local governments) were used for the development of a DI for 199 wastewater treatment plants in Korea. The total DI was calculated from the weighted sum of the disaster indices of the three natural disasters (i.e., TI for typhoon, RI for heavy rain, and EI for earthquake). The three disaster indices of each natural disaster were determined from four components, such as possibility of occurrence and expected damages. The relative weights of the four components to calculate the disaster indices (TI, RI and EI) for each of the three natural disasters were also determined from AHP. PCA was used to determine the relative weights of the input variables to calculate the four components. The relative weights of TI, RI and EI to calculate total DI were determined as 0.547, 0.306, and 0.147 respectively.

• 설비공학논문집
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• 제18권5호
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• pp.451-457
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• 2006

Conjugate heat transfer (CHT) is the simultaneous, coupled heat transfer within a fluid and an adjoining solid, and the interface treatment plays an important role in its analysis, particularly when using unstructured grid system. In the present paper a new solid-fluid interface treatment in CHT analysis is presented and applied to two typical CHT problems, i.e. natural convections in both concentric thick-walled cylinders and cavity with a centered solid body. The present interface treatment for unstructured mesh clearly demonstrates the same accuracy and robustness as that for typical structured mesh.

• 한국농공학회지
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• 제42권5호
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• pp.94-102
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• 2000

Investigated was the effectiveness of a constructed wetland system on water quality in Hwa-Ong estruarin reservoir, located in Hwasung-Gun, Kyunggi-Do. Procedures for estimation of pollutant loading from watershed and required area for natural systems, and simulation of corresponding reservoir water quality were reviewed. Generally, simulated reservoir water quality was within the reasonable range, and about 15% of total polder farmland was required to meet the agricultural water quality standards. The model was applied based on the current loading condition without additional treatment systems. Wetland system is an ecologically sound treatment system. Therefore, natural systems can be an alternative measure for water quality improvement in polder projects. The area for natural systems was estimated using literature value which might be acceptable at the planning stage. However, pilot system and its experimental data are requisite for large scale field application. WASP5 was proved to be a useful and versatile model, and its application to estuarine reservoir water quality simulation was thought to be appropriate.

• 유기물자원화
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• 제4권1호
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• pp.61-72
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• 1996

최근 축조된 습지를 이용한 폐수처리에 대한 관심이 높아지고 있다. 이는 습지이용시스템이 자연정화법을 이용한 처리법으로써 에너지의 소모량이 적고 유지관리가 비교적 간단하며 기술적 난점이 적기 때문으로 판단된다. 그래서 이러한 시스템은 우리나라 농촌지역에서 특히 응용될 수 있는 처리법이라고 생각된다. 본 논문에서는 이러한 처리법을 우리나라에서 적용할 수 있도록 미국 등 구미선진국에서 개발된 축소형 습지에 대한 설계기준에 대해서 논하였다. 본 논문에서 중점적으로 논한 것은 식생의 종류, 자연적 천이와 관리, 식재기법, 파종기법 및 건설 후의 관리이다.

• 한국미생물·생명공학회지
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• 제8권2호
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• pp.135-142
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• 1980

The process of biological treatment of organic wastewater is principally associated with those of self-purification in the natural water environment. The treatment system has e intensive function of stabilizing wastewater more effectively than in natural water, which is like natural water concentrated in a small space. Biological treatment of wastewater involves activated sludge and various modified process, trickling filter, rotating disk, oxidation ditch, etc. for aerobic decomposition and anaerobic processes such as anaerobic decomposition and methane fermentation. The basic characteristic of these processes is the use of mixed culture for the conversion of pollutants. This review forcuses on the various kinds of microorganisms related to each treatment processes. Kinetic analysis of the activated sludge process is discussed in order to understand the basis of control and maintenance of the biological treatment process.

• 한국융합학회논문지
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• 제11권10호
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• pp.213-217
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• 2020

천연 광물질, 식물질, 정수장 슬러지를 이용하여 친환경적인 수수질정화제와 이를 활용하는 오폐수복합처리시스템을 개발하였다. 오폐수복합처리시스템은 오염수 유입, 수질정화제 투입, 가압부상장치 가동, 슬러지 부상, 슬러지 수거 및 처리수 배출의 과정을 거친다. 이 장치를 축분 탈리액, 육계 세척수, 공장 폐수, 하수종말처리장 및 연못의 녹조제거에 적용하여 우수한 제거율을 얻었다. 유기성 폐기물 정화에 천연 수질정화제를 활용한 예는 조사되지 못했다.