• 한국해양학회지:바다
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• 제24권4호
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• pp.519-534
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• 2019

여름철 인공호수(간월호, 부남호)로 부터의 담수방류시 천수만 수질(영양염, 유기물, 미량금속)에 미치는 영향을 평가하기 위해 2011년 6, 7, 8, 10월에 평상시와 담수방류 시기 각 2회씩의 해수를 채취하였다. 담수가 방류되면 용존 무기 질소(DIN)의 농도가 만내의 모든 수층에서 약 3-4배 증가하였고, 평상시 암모니아성 질소(NH₄⁺-N)가 우세하다가 담수방류시 질산성 질소(NO₃^--N)가 우세하였다. 용존 무기인(DIP)의 경우 내만 표층에서 절반으로 감소하였고 저층에서는 1.5배 증가하였으며 규산염(Si(OH)₄)은 내만 저층에서 2배 증가하는 모습을 보였다. Redfield ratio는 담수 방류시 인 제한 환경으로 바뀌었다. 용존 유기 탄소(DOC) 및 질소(DON)는 약 2배 증가하였고, 입자상 유기 탄소(POC), 질소(PON), 인(POP) 및 생물기원 규소(Bio-SiO₂)는 내만 표층에서 약 2배 이상 증가했다. 용존 금속(Fe, Co, Ni, Cu)은 내만의 표층에서 증가하였으나, 용존 Cd의 경우 만의 표층에서 절반으로 감소하였다. 이와 같은 결과로 미루어 볼 때 영양염, 유기물 및 금속 농도가 높은 인공호수의 물이 만으로 유입되면, 천수만 내의 영양염 및 용존 유기물, 금속농도가 증가하고, 식물플랑크톤 대증식이 발생하여 표층에서 산소 과포화, 저층에서 빈산소를 발생시킨다. 빈산소와 함께 내만의 저층에서는 매우 높은 농도의 영양염(DIN, DIP, Si(OH)₄) 농도가 존재하였다. 수질 평가 지수값을 통해 천수만의 부영양화 정도를 평가한 결과, 평상시에는 3등급 이하로 나타나다가 방류시 5등급으로 바뀌게 됨을 알 수 있었다.

• 한국물환경학회지
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• 제36권6호
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• pp.581-591
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• 2020

In this study, two types of reactors were operated to examine the properties of methanol uptake under the high-rate denitrification process. In a sequencing batch reactor, the denitrifying activity was enriched up to 0.80 g-N/g-VSS-day for 72 days. Then, the enriched denitrifying sludge was transferred to a completely stirred tank reactor (CSTR). At the final phase on Day 46-50, the nitrogen removal efficiency was around 100% and the total nitrogen removal rate reached 0.097±0.003 kg-N/㎥-day. During the continuous process, the sludge settling index (SVI30) was stabilized as 118.3 mL/g with the biomass concentration of 1,607 mg/L. The continuous denitrifying process was accelerated by using a sequencing batch reactor (SBR) with a total nitrogen removal rate of 0.403±0.029 kg-N/㎥-day with a high biomass concentration of 8,433 mg-VSS/L. Because the reactor was open to ambient air with the dissolved oxygen range of 0.2-0.5 mg-O2/L, an increased organic carbon requirement of 5.58±0.70 COD/NO3--N was shown for the SBR in comparison to the value of 4.13±0.94 for the test of the same biomass in a completely anaerobic batch reactor. The molecular analysis based on the 16S rRNA gene showed that Methyloversatilis discipulorum and Hyphomicrobium zavarzinii were the responsible denitrifiers with the sole organic carbon source of methanol.

• 한국환경과학회지
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• 제8권4호
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• pp.443-449
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• 1999

This paper describe the working of algal culture system under batch and continuous feeding effluents in biological treatment process. The main objective of this study was the determination of fundamental opeating parameters such as dilution rates, light intensity, biomass concentration, nutrients contents, which engender an effective nutrient and organic waste removal process. The results of this research indicate that the algae system will remove effectively nutrient and organic waste. In batch cultures, 91.8% dissolved orthophosphate and 83.3% ammonia nitrogen were removed from the sewage in ten days. In continuous flow systems, a detention time of 2.5 days was found adequate to remove 91% T-P, 87% T-N and 95% $NH_3-N$. At 22-28$^{\circ}C$, 60 rpm, with an intensity of 3500 Lux, the specific growth rate, k was 0.59/day in batch experiments. The optimal growth temperature and nutrients rate (N/P) were respectively $25^{\circ}C$ and 3~5. With an abundant supply of untrients, it was possible to sustain substantial population densities in the temperature range of 22~28$^{\circ}C$.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.604-609
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• 2005

Runoff characteristics of organic matters and nutrients from greenhouse site in paddy field area were investigated during the irrigation period in 2004. The greenhouse selected which situated near the Nam river, Jinju, Korea used the ground water as the irrigation purpose. And, the rotating system of paddy field to upland was adapted as a cropping system which is a typical practice in this area. Various items such as total phosphorus(T-P), total nitrogen(T-N), dissolved oxygen(DO), BOD, etc. were observed to figure out the seasonal and spatial variation in the study sites. it was found that the risk of water pollution due to the contamination of nutrients in canals in green house sites, and their neighbouring small sized streams are much higher than those in ordinary paddy field areas. Further surveys and investigations are required to find out the counter measures to reduce water pollution occurred in greenhouse sites.

• Bulletin of the Korean Chemical Society
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• 제20권4호
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• pp.431-435
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• 1999

An organic precipitate flotation of Cd(Ⅱ) and Pb(Ⅱ) was investigated by the coprecipitation with lanthanum 8-hydroxyquinolinate. Trace amounts of Cd(Ⅱ) and Pb(Ⅱ) with a significantly large amount of La(Ⅲ) were simultaneously precipitated in a 1,000 mL sample solution with the ethanolic 8-hydroxyquinoline solution. The pH was adjusted to 9.0 with 2 M ammonia solution. The precipitates were floated with the aid of tiny nitrogen bubbles and supported by the stable foam layer of sodium lauryl sulfate. The floats were collected on the fritted glass filter by a suction. The material collected was dissolved with 5.0 mL of ethanol and 1.5 mL of concentrated nitric acid, and then diluted to 25.0 mL with a deionized water. The analytes were determined by a flame atomic absorption spectrophotometry. The recoveries of the analytes spiked in the sample were 94.8% for Pb(Ⅱ) and 92.0% for Cd(Ⅱ). This flotation technique is simple and rapid, and also applicable to the determination of trace Cd(Ⅱ) and Pb(Ⅱ) at lew ppb levels.

• 한국물환경학회지
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• 제35권2호
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• pp.165-180
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• 2019

Water quality data of 81 lakes in Korea, 2013 ~ 2017 were analyzed. Most water quality parameters showed left-skewed distribution, while dissolved oxygen showed normal distribution. pH and dissolved oxygen showed a positive correlation with organic matter and nutrients, which appeared to be a nonsense correlation mediated by the algae. The ratio of $BOD_5$ and $COD_{Mn}$ to CBOD was 21 % and 52 % in the freshwater lakes, respectively. TOC concentration appeared to be underestimated by the UV digestion method, when salinity exceeds $700{\mu}S\;cm^{-1}$. In terms of nitrogen/phosphorus ratio, the limiting factor for algal growth seemed to be phosphorus in most of the lakes. Chlorophyll ${\alpha}$ increased acutely with decrease of N/P ratio. However, it seemed to be a nonsense correlation mediated by phosphorus concentration, since the N/P ratio depended on phosphorus. The N/P ratio of brackish lakes was lower than that of the freshwater, at the same concentration of phosphorus. It is worth examining denitrification that occurs, in bottom layer and sediment, during saline stratification. $Chl.{\alpha}$ concentration decreased in the form of a power function with increase of mean depth. The primary reason is that deep lakes are mainly at the less-disturbed upstream. However, it is necessary to investigate the effect of sediment, on water quality in shallow lakes. Light attenuation in the upper layer, was dominated by tripton (non-algal suspended solids) absorption/scattering (average relative contribution of 39 %), followed by CDOM (colored dissolved organic matter) (average 37 %) and $Chl.{\alpha}$ (average 21 %).

• Journal of Korean Society for Atmospheric Environment
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• 제14권E호
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• pp.27-40
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• 1998

The solubility characteristics of organic compounds were studied in terms of the extraction efficiency as a function of the polarity of the organic solvent, and the acidity of water in urban aerosol samples collected in University of East Anglia (UEA), Norwich, England. The extraction efficiency of organic compounds were evaluated with respect to the organic carbon, -nitrogen and -hydrogen by means of a wide range of solvent which include polar and nonpolar organic solvents as well as acids and alkaline water. In addition, after being dissolved in aqueous solution, the aqueous chemistry of organic compounds were studied in terms of the organic metal complexes in aerosol, which were studied with oxalic acid, copper, and zinc. The results of this study indicate that solubility characteristics of organic compounds depend on the polarity of the solvents and the acidity of the solvents. In particular, some organic compounds are water soluble, even though they are much smaller than acetone soluble fractions. In the comparison between polar organic solvent extraction and non- polar organic solvent extraction, it can be thought that significant fraction of organic compounds analysed in the aerosol samples, are polar organic compounds because of the higher extraction efficiencies of organic compounds in polar organic solvent extraction than in nonpolar organic solvent extraction. Regarding the study of the oxalic -metal complexes, it can be thought that most oxalic acids are present in the form of oxalic -copper complexes in the aerosols collected at UEA.

• 한국습지학회지
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• 제19권2호
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• pp.216-222
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• 2017

현재 국내 하수처리장 방류수 질소 수질 기준 개정의 필요성에 대한 의견들이 지속적으로 제안되고 있다. 하지만, 명확한 근거 없이 기준이 강화될 경우 국내 하수처리장에 혼란을 야기할 것이 자명하다. 본 연구에서는 장기 배양법을 기반으로 용량 및 산업단지 연계 처리에 따른 국내 하수의 질소 성상을 분석하였다. 분석 결과, 하수처리장에서 처리되기 어려운 질소 성분인 NBDDON는 1.0 ~ 1.9 mg/L 범위를 보였으며, 하수처리장 용량이 적을수록 DON 농도 & NBDDON/DON가 증가하였다. 또한 도시하수를 처리하는 하수처리장보다 산업단지 하수처리장의 NBDDON/DON 비가 높은 것으로 조사되었다. 본 연구의 결과는 향 후 국내 하수처리장 방류수 수질 기준 개선을 위한 중요한 기초 자료로 활용될 것이라 전망한다.

• 대한환경공학회지
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• 제39권8호
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• pp.470-477
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• 2017

본 연구에서는 유기물 및 영양염류로 오염된 해양퇴적물 정화를 위한 석회석, 모래, 제올라이트 피복 공법의 적용성을 평가하였다. 수조 실험을 위한 퇴적물 및 해수 시료는 평택항에서 채취하였으며, 채취된 시료 위에 석회석, 모래, 제올라이트를 1 cm 또는 3 cm 두께로 피복하였다. 63일 동안 수층의 수소이온 농도(pH), 전기전도도(EC), 용존 산소(DO), 화학적 산소 요구량(COD), 총질소(TN), 총인(TP)을 측정하였다. 평택항 퇴적물을 분석한 결과 유기물과 총질소 오염이 높게 나타났다. 미피복 수조에서는 실험 시작 후 10일 이내에 DO가 고갈되었지만, 제올라이트 3 cm 피복을 제외하고 모든 피복 조건에서는 실험 기간 동안 용존 산소는 2 mg/L 이상 유지되었다. COD의 용출 차단 효율은 제올라이트 1 cm > 석회석 1 cm > 석회석 3 cm > 모래 3 cm ${\cong}$ 제올라이트 3 cm ${\cong}$ 모래 1 cm 순으로 나타났다. 질소의 용출 차단에는 제올라이트 피복이 효과적이었다. T-P는 미피복 및 피복 수조 모두에서 나타나지 않았다. 본 연구 결과 제올라이트는 유기물 및 질소 농도가 높은 오염퇴적물 정화를 위한 피복 소재로서 활용될 수 있을 것으로 판단된다.

• 해양환경안전학회지
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• 제22권1호
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• pp.1-10
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• 2016

본 연구에서는 함평만의 육상기인오염 물질의 유입특성을 파악하고, 물질순환을 정량화하기 위해, Simple box model을 적용하였다. 함평만의 하천 유입 오염부하 특성을 보면, BOD, COD, TOC의 평균 유기물질 오염부하가 각각 79.7 kg-BOD/day, 144.06 kg-COD/day, 93.0 kg-TOC/day를 나타내었다. 하천별 유기물 유입 오염부하량은 손불 방조제>주포교>양만단지 순으로 나타났다. 계절별로는 하계 강우시기인 7월에 높은 부하 특성을 보였다. 영양염류의 평균 유입 오염부하는 각각 20.9 kg-DIN/day, 17.1 kg-DIP/day, 148 kg-TN/day, 37.4 kg-TP/day를 나타내었다. 하천별 영양염 유입부하량은 양만단지>백옥교>주포교 순으로 나타났다. 박스모델을 이용한 함평만 물질수지에서 담수체류시간은 52.4일로 해수교환이 낮은 반 폐쇄성 해역의 특성을 나타내었다. 영양염 물질수지에서 용존 무기질소의 경우 ${\Delta}DIN$이 (-)의 탈질상태를 나타내어 유입된 질소보다 광합성에 의한 소비 및 외해 유출이 큰 경향을 보였다. 용존 무기인의 경우 ${\Delta}DIP$가 (+)를 나타내어 유기물 분해에 의한 공급, 퇴적물의 용출부하, 하천 유입부하가 식물플랑크톤에 의한 소비 및 외해 유출보다 큰 것으로 나타나 축적되는 경향을 보였다.