• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.425-428
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• 2002

This study has been carried out to analized of long term changes of water quality with regard to main pollutant sources in agricultural reservoirs on the basis of data during 1996-2001. The major source was domestic wastewater(DWW) and water pollution by non-point sources(NPS) is increasing as time goes. It was determined that Seasonly average values of DWW were pH $7.6{\sim}8.7$, COD $7.0{\sim}9.4$, T-N $0.74{\sim}2.07$, T-P $0.05{\sim}0.62$, Live-stock wastewater(LWW) were pH $7.5{\sim}8.9$, COD $5.5{\sim}9.8$, T-N $0.57{\sim}1.91$, T-P $0.04{\sim}0.13$, NPS were pH $7.1{\sim}8.3$, COD $3.1{\sim}5.2$, T-N $0.29{\sim}1.44$, T-P $0.02{\sim}0.07$. Fluctuation of DWW and LWW were very wide and variable long term patterns of them were similar. Trophic states by Carlson Index of DWW and LWW was classified as eutrophic to hypretrophic from chl-a, T-P concentration.

• 한국농공학회논문집
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• 제48권3호
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• pp.97-106
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• 2006

The pollutant concentrations at experimental paddy plots with three (excessive, standard, reduced) different fertilization rates were investigated during 2001-2002 irrigation seasons. Mean concentrations of pollutants in ponded water were not significantly different among three experimental plots, but the T-N concentrations in percolated water significantly depended on fertilization rates. The T-N, T-P and $COD_{Cr}$, concentrations in ponded water during early irrigation season (late May to mid-June) were much higher than those during later irrigation season likely due to fertilization and low uptake by young rice crops. The T-N concentrations decreased but the concentrations of T-P and $COD_{Cr}$, increased three days after tillering fertilization. The removal rates of T-N by paddy plots were $0.13-0.16g/m^2{\cdot}d$ for an excessive fertilization plot, $0.08-0.25g/m^2{\cdot}d$ for a standard fertilization plot, and $0.03-0.34g/m^2{\cdot}d$ for a reduced fertilization plot three days after tillering fertilization. On the other hand, T-P and $COD_{Cr}$, were released three days after tillering fertilization.

• 대한환경공학회지
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• 제29권3호
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• pp.304-310
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• 2007

본 연구는 초단파조사 처리된 잉여슬러지를 하수와 함께 활성슬러지공법으로 처리할 때 하수처리효율과 잉여슬러지 발생량에 미치는 영향을 파악하기 위하여 실시되었다. 온도가 $20^{\circ}C$이고 MLSS농도가 약 2,000 mg/L인 250 mL의 잉여슬러지를 발진주파수가 2,450 MHz이고 정격고주파출력이 700 W인 전자렌지(microwave oven)로 초단파조사 처리한 결과 조사시간이 1분 증가함에 따라 수온이 약 $20^{\circ}C$씩 증가하였으며, 슬러지의 SCOD, TKN 및 T-P 농도는 모두 $40\sim130$ sec의 조사시간에서 가장 많이 증가하였다. 그리고 혼합액 미생물의 산소섭취율을 측정한 결과 130 sec 이상의 조사시간($65^{\circ}C$ 이상)에서는 혼합액의 미생물이 거의 사멸하는 것으로 나타났다. 잉여슬러지를 초단파조사 처리한 다음 하수와 혼합시켜 활성슬러지공법으로 처리하였을 때 유입수 및 처리수의 pH 및 알칼리도에는 거의 영향이 없었으나, 유입수의 SS, COD, T-N 및 T-P 농도는 증가하였으며, 처리수의 SS, BOD 및 T-P 농도는 거의 영향을 받지 않았으나 COD 및 TKN 농도는 증가하였다. 그리고 초단파 조사비가 1 g SS/g SS-day 증가할수록 미생물성장계수 값은 0.91 g SS/g COD removed의 율로 감소하였다.

• 한국지반환경공학회 논문집
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• 제1권1호
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• pp.79-85
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• 2000

이 연구는 지방의 중소도시에 위치한 소규모 단순매립지내의 매립폐기물과 침출수에 대한 분석을 통하여 안정성을 평가함으로써 매립부지를 주거지역, 상업지역, 기타 다른 목적으로 사용하기 위함이다. 단순투기형으로 매립된 매립층의 깊이는 5.5~8m 정도이었고, 복토 두께는 20~50cm 정도이었다. 매립지의 침출수의 pH는 7.2~7.6이었고, SS, COD, T-N 및 T-P값은 각각 평균 47726, 6193.8, 595.97, 123.9mg/L로 높은 값을 보였으나 BOD/COD비가 0.079로 침출수가 안정화되어 있음을 알 수 있었다. 또한 폐기물의 용출분석결과 COD, BOD 모두 낮은 값을 보였으며 T-N, T-P 각각 7.77, 0.20mg/L의 값을 나타내었고 침출수와 비교하여 모두 현저히 낮은 결과를 보임으로써 폐기물중 생분해성 유기물의 분해가 역시 완료되었음을 알 수 있었다. 이상의 연구 결과 대상 폐기물 매립지는 안정화 단계에 있어 침출수의 발생량은 앞으로 현저하게 감소될 것으로 예측됨으로써, 매립지내로 유입 가능성이 크게 의심되는 지하수의 차단에 의한 침출수 방지 대책 등이 보강될 경우에는 토지의 재이용이 가능할 것으로 판단된다.

• 한국습지학회지
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• 제16권1호
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• pp.51-59
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• 2014

본 연구의 목적은 직렬연결 수직 및 수평 흐름 갈대 제올라이트 인공습지에 생활하수를 간헐적으로 주입하였을 때 처리효율을 조사하는 것이다. 각 항목별 유입수에 대한 평균 처리효율은 수직 흐름 인공습지 유출수에서 BOD 92.42%, $COD_{Cr}$ 79.02%, $COD_{Mn}$ 80.62%, SS 98.33%, T-N 37.06%, $NH{_4}^+-N$ 99.45%, T-P 57.96%이었으며 수평 흐름 인공습지 유출수에서 BOD 95.56%, $COD_{Cr}$ 91.02%, $COD_{Mn}$ 87.78%, SS 99.22%, T-N 45.87%, $NH{_4}^+-N$ 99.88%, T-P 71.17%이었다. 최종 유출수 중 T-N은 대부분이 $NO{_3}^--N$이었으며 $NO{_2}^--N$은 평균 0.04mg/L 이하이었다. 특히, 갈대 제올라이트 인공습지는 SS와 $NH{_4}^+-N$의 처리에 탁월하였다.

• 환경영향평가
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• 제28권2호
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• pp.83-100
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• 2019

본 연구는 팔당호 내 4개 지점을 대상으로 각 지점에서의 장기 수질 변화 및 지점 간 시차성을 확인하기 위하여 비모수적 추세분석 방법인 Seasonal Kendall test, LOWESS와 Cross Correlation을 수행하였다. 본 분석을 위하여 2004년 1월부터 2016년 12월까지, 각 지점별 9개 수질 항목(수온, EC, DO, BOD, COD, T-N, T-P, TOC, Chl-a)의 주별 분석 자료를 사용하였다. Seasonal Kendall test 결과 수온은 증가, EC와 T-N, T-P는 전 지점 모두 감소 경향을 나타내었다. LOWESS 결과 BOD 농도는 전 지점에서 2013년부터 2016년까지 "감소" 경향을 나타내었고 COD는 2012년부터 "증가" 경향을 나타내었다. 따라서 2012~2013년은 팔당호 전 지점에서 BOD의 개선과 함께 COD의 증가가 나타나는 전환기였음을 확인할 수 있었다. Cross Correlation 결과, 모두 시차성 없음으로 나타났다. 본 연구를 통하여 팔당호에 대한 보다 적합한 수질관리를 위하여 위의 전환기에 대한 발생원인 분석과 함께 수질 측정주기의 증가를 통한 보다 정밀한 모니터링이 필요할 것으로 판단된다.

• 한국환경보건학회지
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• 제34권3호
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• pp.255-260
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• 2008

This study was conducted to analyse the effects of the UFCA for treating polluted water in a reservoir. The UFCA mixes water by circulation of surface and bottom water layers. The circulation supplies oxygen to bottom of the reservoir, resulting in water quality improvement. With a UFCA in use, we surveyed the changes of temperature, pH, transparency, depth, conductivity, DO, COD, BOD, T-N, T-P and Chlorophyll-a for 7 months from Feb. to Aug. in 2004 in our experimental reservoir. There was little difference in the surface and bottom temperatures of the reservoir because of water mixing by the UFCA. However, pH was changed from 7 to 9. The transparency of water was about 80 cm through the all periods. Conductivity was $150\;{\mu}S/cm$ in early Feb., but increased to $270\;{\mu}S/cm$ in early March. Little change was seen in DO with depth, but it was maintained above 6 mg/l in June and July. BOD increased from 2.1 to 12.2 mg/l. The study reservoir did not undergo any eutrophication during the period of our experiment, but the comparison reservoir had an algae-bloom. The COD in the experimental reservoir increased from 5.4 to 14.5 mg/l. The COD concentration of the experimental reservoir was higher than comparison reservoir at the beginning of the study but in August this situation was reversed. SS concentration increased from 13.5 to 23.5 mg/l in Feb., but it fell from between 8.5 to 11.2 mg/l in July. T-N was increased from 1.3 to 4.9 mg/l. It increased up to 3 times in the rainy season as compared to other components. However the comparison reservoir increased up to 40 times higher than the experimental reservoir in the same period. T-P increased from 0.04 to 0.17 mg/l. The ratio of T-N to T-P increased from 20:1 to 40:1 which means that T-P was a growth limiting factor for algae and aquatic plants. Chlorophyll-a increased from 20 to 120 mg/l, and its concentration was correlated with T-P, such that Chlorophyl-a concentration increased with increased of T-P concentration. The concentrations of COD, T-N, T-P and other parameters were higher in the experimental reservoir than in the comparison reservoir but this situation was reversed in July, when the most severe eutophication occurred. The results show that overall the experimental reservoir was greatly remedied by UFCA. The UFCA accelerated the degradation of aquatic organic materials through effective supply of air with up-flow and circulation of water. We conclude that the UFCA can be very effective in aspect of the remediation of water quality incontaminated reservoirs and lakes.

• 환경위생공학
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• 제11권1호
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• pp.45-55
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• 1996

An experimental research was conducted in order to study the combined treatment o of municipal landfill leachate and municipal sewage. The landfill leachate was that of Nanjido landfill site, and the municipal sewage was that of Chungnang municipal sewage treatment plant in Seoul. Several sets of bench~scale sequencing batch reactor(SBR) were used as e experimental apparatus. Specially investigated items in this experiment were the removal efficiency of substrate and the influence of treatment time. The experiment lasted for about 2 years. The result are as follows ; 1. The characteristics of leachate were pH 7.5~8.2, BOD 80~336mg/L, COD 908~1,460mg/L, NH3-N 1,409~2,330mg/L, T~P 2.7~7.lmg/L, Cl~3,540~4,085mg/L, a and heavy metals are a very small amount. And the characteristics of sewage were pH 6.9~7.3, BOD 78.4~129.3mg/L, COD 121.2~305.0mg/L, T~N 14.9~36.4mg/L, T-P 2.3~8.9mg/L. 2. The treatability of leachate alone was not treat well. So for the good treatment of leachate, it was necessary to deal with the pretreatment before bi이ogical treatment and a combined treatment of municipal sewage. 3. The various contents of the leachate were 5%, 10%, 30%, and 50%, and the removal efficiency of COD was 86.0%, 82.8%, 60.6%, and 31.7%. The maximum content of the leachate which could be sucessfully treated by SBR in the combined treatment was 10% of that of sewage. And the removal efficiency of COD increased n notably, as its treatment time increased. 4. The various contents of the electrolytic treated leachate were 5%, 10%, 30%, and 50%, and the removal efficiency of COD was 89.9%, 86.1%, 79.2%, and 69.8%. The maximum content of the leachate which could be sucessfully treated by SBR in the combined treatment was 30 % of that of sewage. And the removal efficiency of C COD increased notably, as its treatment time increased.

• 상하수도학회지
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• 제21권2호
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• pp.225-233
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• 2007

Road runoff water is one of the non-point sources (NPSs) of pollution negatively influencing drinking water source. Numerous road runoff NPS waters have been studied for over the last decade. However, the sources of pollution can be conditional, seasonal, or accidental. Therefore, measurement of pollutant loadings in different site is necessary to estimate the effect of road runoff water. The objective of this study was to examine the quality of road runoff water from a city bridge in Seoul, Korea. This study was conducted for two years to assess annual discharge pollution loads. In this study, key water quality parameters including chemical oxygen demand ($COD_{Cr}$), biochemcial oxygen demand ($BOD_5$), total nitrogen (T-N), total phosphorus (T-P), and suspended solid (SS) were measured at 18 different events. The results showed that typically the pollutant concentrations are higher at the beginning of each event and decrease afterwards. The first 20% of the volume of the runoff from each event is transporting 46% ($COD_{Cr}$), 48% ($BOD_5$), 50% (T-N), 34% (T-P), 30% (SS), respectively. The event mean concentrations (EMCs) were $COD_{Cr}$ (199 mg/L), $BOD_5$ (41.2 mg/L), T-N (7.97 mg/L), T-P (0.42 mg/L) and SS (113 mg/L). Although the results were consistent with the previous study (Barbosa and Hvitved-Jacobsen, 1999), $COD_{Cr}$, $BOD_5$, T-N exhibit a stronger first flush effect compared to the other contaminants.

• 한국환경과학회지
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• 제29권6호
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• pp.659-672
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• 2020

Water and sediment qualities were investigated in the Oncheon Stream and at the Wondong bridge of the Suyoung River, during the summer rainy season, 2019. Dissolved oxygen (DO) showed the lowest levels at 4.7 and 5.0 m/L, and biogeochemical oxygen demand (BOD) showed the highest at 5.3 mg/L downstream where the tributary flows into the main river. Chemical oxygen demand (COD) increased from 2.0 to 5.9 mg/L on average as it flowed downstream, The COD/BOD ratio decreased gradually as it flowed downstream, reaching 1.0. However, COD/BOD ratio at the Wondong bridge was 5.8-22.2, indicating that easily biodegradable and non-biodegradable organic matter flows into the Oncheon Stream and Suyoung River, respectively. Total nitrogen (T-N) / total phosphorus (T-P) ratio tended to decrease from 72 to 21 as it flowed downstream, measuring 71 to 86 at the Wondong bridge. The water quality index (WQI) generally improved better than grade IV after heavy rainfalls. However, DO and T-P were the parameters that deteriorated the WQI. Ignition loss (IL), COD, T-N, and T-P of sediments had distribution of 1.44 ± 1.01%, 0.35 ± 0.16%, 43 ± 63 mg/kg, and 10.9 ± 21.9 mg/kg, respectively. These were several times lower than the annual averages of IL, T-N, and T-P in 2017 before the dredging project was conducted in the first half of 2018.