• Magazine of the Korean Society of Agricultural Engineers
• /
• v.40 no.2
• /
• pp.18-28
• /
• 1998

현재의 가축분뇨처리 형태와 축종별 적용대상은 표 3과 같이 분류되며, 축분 퇴비화 뇨오수 정화방식의 고액분리 형태에서 분뇨혼합물의 동시처리 즉, 깔감축사(소, 돼지), 슬러리 발효 퇴비화를 통한 무방류 시스템으로 변화되는 추세이다. 이러한 현상은 최근의 방류수질 규제강화에 따른 무방류화 저비용 단순화를 지향하고 있으며, 무방류화의 가장 큰 걸림돌은 톱밥과 같은 수분조절재 부족이라 할 수 있다. 현재 이용되고 있는 주요 시스템별 개선안은 다음과 같다. $\square$ 주요 처리 시스템 적용의 문제제기 $\circ$ 축분발효시설 - 톱밥 등 부자재 무이용을 위한 축분의 예비 건조시설 이용 - 교반식 발효기의 악취확산방지를 위하여 밀폐형 하우스 및 강제환기 장치 설치에 의한 악취 포집 및 탈취 - 중소규모 발효시설 개발 $\circ$ 화력건조 - 예비건조를 통한 톱밥, 연료비용 절감 - 악취방치 장치부착 의무화 $\circ$ 활성오니 정화시설 - 시설 운전관리 단순화 - 1차 고액분리를 통한 유입수 오염부하량 감소 및 균일화 $\circ$ 깔감축사 - 경제적으로 흡수를 극대화할 수 있는 수분조절재의 조합비 결정 및 혼합물을 깔감으로 재이용 기술개발 $\circ$ 슬러리 발효퇴비화 시설 - 톱밥 등 수분조절재 사용량 절감기술 - 증발량 극대화 기술개발 및 소요에너지 최소화기술개발 우리나라는 사계절이 뚜렷하여 외기상에 따라 편차가 심하며, 고밀도 사육 및 지역적 편중성, 경지면적 협소, 고비용 시장구조 등의 축산환경을 고려한다면 근원적으로 가축분뇨문제 해결한다는 것은 결코 쉬운 일이 아니다. 이는 저공해 사료개발에서부터 분뇨가 발생단계에서 분리, 수거할 수 있는 수거시설, 고효율 분뇨처리시스템의 정립, 액비 및 퇴비의 가공, 토양환원되었을 때 작물생장장애, 액비, 퇴비의 유통, 가축분뇨처리 정책 및 규제법 등의 각 분야에서 복합적 노력이 필요하다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.29 no.1
• /
• pp.285-290
• /
• 2005

Until now, korean aquaculture industry has been grown largely from a quantitative viewpoint. However, an increase of quantity has caused lots of problems producing a derived effect recently. Nearly 82% of korean aquaculture farms had been installed mainly at inshore of the southern sea and also sewage, factory wastes, high density of fishcage at the limited area and autoinfection have deteriorated inshore fisheries. The offshore have been on the rise for the solution to these problems since it has clear seawater reduces the environmental pollution with much current. As a matter of fact, the existing inshore fishcage facilities have trouble advancing to the offshore due to the rough environmental conditons such as a high sea, strong currents etc.; therefore, it is necessary to develop a new cultivating equipment fit the open sea conditons. In this research, the theoretical study and experimental analysis have been carried out for the fishcage design of the structure which is able to use at the open sea.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.8
• /
• pp.905-910
• /
• 2014

The steel grating discussed in this study is a drain cover that enhances the rigidity of the steel frame using an inclined inflow tract for wastewater, facilitates smooth drainage, and prevents the escape of bad smell from the drain. Recently, the urban problem of bad smell in sewerage lines has been hindering the improvement of living standards. Moreover, the frequent failure of existing products deters bad smell prevention measures and results in administrative power and budget wastage. The pressure to reduce budgets propels the increased demand for functional steel grating. Thus, this study focused on optimizing the design parameters of a steel grating by simultaneously considering its rigidity and drainage efficiency.

• Journal of Korean Society of Forest Science
• /
• v.94 no.1 s.158
• /
• pp.1-5
• /
• 2005

This study was carried out to survey the growth and the photosynthesis of Salix gracilistyla, the reduction rate of nitrogen and phosphoric acid by the plant grown in waterway soil. The results were summarized as follows; I. The contents of nitrogen and phosphoric acid at waterway soils of Mangyeong river showed the highest level in the around Samrye railway bridge where was located in the downstream and livestock complex. 2. The Salix gracilistyla which grown in waterway soil showed that the growth of stem length and diameter were 170~215% and 42.3~79.3%, respectively. In addition the growth rate of Salix gracilistyla was increased with increasing nitrogen concentrations in waterway soils. 3. The rate of photosynthesis was high in waterway soil contained high nitrogen and it appeared the highest in August. 4. The nitrogen and phosphoric acid by Salix gracilistyla grown in waterway soil were removed about 14~15% and 9~11 %, respectively. The Salix gracilistyla was effective removing nitrogen more than phosphoric acid.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2015.05a
• /
• pp.385-385
• /
• 2015

정부는 1998년부터 4대강 물관리종합대책을 세워 하천의 수질보전을 위한 대책을 시행하고 있다. 그 중 대유역 중심의 수질개선대책은 전체적인 큰 목표를 제시하는 것이며, 이러한 대유역의 목표수질을 달성하기 위해서는 먼저 소유역의 수질개선이 이루어져야 한다. 현재 영산강유역에서는 도시하수종말처리장, 산업폐수처리장과 같은 점오염원 관리시설은 대폭 확충되었으나 하천과 호소의 수질은 크게 향상되지 못하고 있다. 이는 중 소유역에 대한 효율적인 수질개선대책이 없기 때문이며, 특히 중 소유역 내 비점오염원 물질이 대량으로 하천 및 호소에 유입되기 때문이다 따라서 효율적인 유역관리를 위해서는 소유역중심의 관리가 필요하며, 소유역 중심의 수질보전 대책을 수립하기 위해서는 대상 소유역에 대한 조사분석이 선행되어야 하는데, 여기에는 관거(우수관, 오수관) 시스템 조사와 하수의 차집조사가 관계되며, 또한 소유역내의 오염원(점오염원과 비점오염원) 및 잠재적인 오염원조사 등과 같은 광범위한 조사 작업이 필요하다. 한편 유역모형 중 HSPF모형은 모형의 적용에 필요한 방대한 자료와 노력을 최소화 되도록 개발되어 왔으며, HSPF는 광범위한 수문 수질과정을 장기 모의가 가능하도록 일련의 구조화된 모듈로 구성되어 있다. 복잡한 모형일수록 자료관리에 많은 노력이 요구되나 HSPF는 자료를 직접적으로 접근할 수 있는 Time Series Management System에 가깝도록 개발되었다. 또한, HSPF 모델은 유역내의 토지이용에 따른 특정 오염물질의 비점오염 부하를 계산하며, 강우에 따른 물의 흐름을 하천의 수질오염모의와 연결시키는데, 광범위한 유역조건에 적용이 가능하고, 각 소유역을 구분하여 비교가 가능하므로 소유역별 관리방안을 비교하는데 가장 적합한 모델이다. 따라서 본 연구는 유역모형(HSPF)을 이용하여 영산강 유역을 대표할 수 있는 중 소유역을 선정하고, 선정된 중 소유역에 대한 기초적인 자료를 조사 분석하여 종합적이고 구체적인 유역 관리계획을 수립해 봄으로써 중 소유역 수질관리에 지침서로서 역할을 하는데 목적이 있다.

• Korean Journal of Environmental Agriculture
• /
• v.12 no.1
• /
• pp.19-25
• /
• 1993

The water quality at Seomjin River stream was surveyed at 8 sites of main stream and 4 sites of tributaries for 6 months from April to September in 1989. The overall results are summarized as follows: 1. Do concentration of main stream ranged from 7.5 to 9.0 ppm. 2. The average $No_3-N$ content of main stream was increased to 3.86 ppm at June, thereafter it was decreased by dilution with rainwater. 3. The water quality of Seomjin River stream was suitable for the irrigation source with the exception of site 8 where the contents of EC, $Cl^-$ and $SO_4\;^{2-}$ were very high according to the influence of sea water. 4. In the influence of tributaries on changes of the water quality along the Seomjin River, the water quality of main stream was deteriorated with inflow of Osu-cheon and Yo-cheon in the middle stream, but thereafter it was recovered with inflow of Boseong River and Hwangjeon-cheon. 5. The Yo-cheon was rapidly polluted by the sewage of Namweon city, that is, contents of COD and $NO_3-N$ were incresed from 0.97 to 7.10 ppm and from 1.86 to 3.11 ppm respectively.

• Journal of Korea Soil Environment Society
• /
• v.1 no.2
• /
• pp.35-42
• /
• 1996

Seawater samples were collected from P'ohang coastal area during April 1995 - January 1996. The distribution of total heterotrophic bacteria and crude oil-degrading bacteria (CDB) were studied. In addition, biodegradation of crude oil was investigated through mono and mixed culture. The heterotrophic bacterial distribution was in the range of 4.1 $\times$ $10^4$- 1.2 $\times$ $10^5$ CFU/$m\ell$, respectively. The percent of crude oil-degrading bacteria against total heterotrophic bacteria was 0.05-0.54% which was lower than other marine samples reported. Therefore it could be suggested that the distribution of crude oil-degrading bacteria in the seawater of P'ohang coastal area was highly affected by presence of petroleum hydrocarbon. Taxonomical characteristics of 26 isolates were investigated. The results of identification were showed 7 genera which were Acinetobacter spp., Bacillus spp., Citrobacter spp., Micrococcus spp., Moraxella spp., Rhodococcus spp., and Serratia spp. Appearance of Enterobacteriaceae indicated that the seawater was polluted with wastewater. Also genus of Bacillus had predominant in CDB on P'ohang coastal area. In flask culture, biodegradation of crude oil was enhanced by addition of mixed culture of CDB.

• Journal of the Mineralogical Society of Korea
• /
• v.19 no.1 s.47
• /
• pp.49-61
• /
• 2006

This study was undertaken to investigate the origin of suspended matter to induce turbidity water in Gachang dam in view of environmental geology. During the period from May to August 2004, field works and sampling were carried out three times at the dam and along its streams, and chemical and mineralogical analyses such as ICP, IC, particle size analyzer, XRD and SEM were made on water, soil and suspended matter in water. Electrical conductivity (EC), turbidity, the contents of cation and anion increase from upstream toward the dam mostly due to the geological factors such as weathring of the rocks causing the increase of the total ion content. Vermiculite, illite, kaolinite, quartz, feldspar and iron hydroxide are commonly found in suspended matters in water and soils. Finer particles (d10) in soil increase slightly toward downstream and the vermiculite content is highest in the dam water. Since geological differences are not significant, mineralogy are similar in suspended matters and soils. Clay mineral compositions present in suspended matters were alsmost the same as those in soils, indicating the origin of soils by weathering of host rocks and being transported to the dam by stream water.

• Journal of Life Science
• /
• v.7 no.1
• /
• pp.1-9
• /
• 1997

For the recent years, considerable efforts have been made to rationalize the techniques of research and monitoring of biological effects of marine pollutants such as heavy metals, polychlorinate biphenyls (PCBs), organochlorine pesticides, polycyclic aromatic hydrocarbons (PAHs), organophosphorus pesticides. This study was designed as a part of efforts to investigate the biochemical pollutant markers for diagnosis of marine pollutions by the changes in lipid components of the flounder (Paralichthys olivaceus) in Yellow Sea of Korea. Homoglobin levels in serum of cultured and wild flounders in Yellow Sea were significantly lower (5 - 15% and 20 -25 % , respectively) than those of wild flounder in Pohang. Triglyceride (TG) contents in serum of cultured flounders in Yellow Sea were 10 - 40% higher than those of wild flounder in Pohang. Total and low density lipoprotein (LDL)-cholesterol contents in serum of flounders in Yellow Sea were significantly 10-15% and 30-35% (cultured), and 10-20% (wild), respectively, higher than those of wild flounder in Pohang. Atherogenic index (AI) and T-Chol/PL rations in serum of cultured and wild flounders in Yellow sea were significantly 20-45% and 10-!5%, 6-35% and 15-35%, respectively, higher than those of wild flounder in pohang. These results suggest that near-coastal waters as well as neritic waters of the Yellow Sea might be affected by pollutant input.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.23 no.2
• /
• pp.53-69
• /
• 2020

The increase of the impermeable area due to industrialization and urban development distorts the hydrological circulation system and cause serious stream drying phenomena. In order to manage this, it is necessary to develop a technology for impact assessment of stream drying phenomena, which enables quantitative evaluation and prediction. In this study, the cause of streamflow reduction was assessed for dam and weir watersheds in the five major river basins of South Korea by using distributed hydrological model DrySAT-WFT (Drying Stream Assessment Tool and Water Flow Tracking) and GIS time series data. For the modeling, the 5 influencing factors of stream drying phenomena (soil erosion, forest growth, road-river disconnection, groundwater use, urban development) were selected and prepared as GIS-based time series spatial data from 1976 to 2015. The DrySAT-WFT was calibrated and validated from 2005 to 2015 at 8 multipurpose dam watershed (Chungju, Soyang, Andong, Imha, Hapcheon, Seomjin river, Juam, and Yongdam) and 4 gauging stations (Osucheon, Mihocheon, Maruek, and Chogang) respectively. The calibration results showed that the coefficient of determination (R²) was 0.76 in average (0.66 to 0.84) and the Nash-Sutcliffe model efficiency was 0.62 in average (0.52 to 0.72). Based on the 2010s (2006~2015) weather condition for the whole period, the streamflow impact was estimated by applying GIS data for each decade (1980s: 1976~1985, 1990s: 1986~1995, 2000s: 1996~2005, 2010s: 2006~2015). The results showed that the 2010s averaged-wet streamflow (Q95) showed decrease of 4.1~6.3%, the 2010s averaged-normal streamflow (Q185) showed decreased of 6.7~9.1% and the 2010s averaged-drought streamflow (Q355) showed decrease of 8.4~10.4% compared to 1980s streamflows respectively on the whole. During 1975~2015, the increase of groundwater use covered 40.5% contribution and the next was forest growth with 29.0% contribution among the 5 influencing factors.