수산자원보호구역의 유기물과 중금속 분포특성을 파악하기 위하여 2017년 2월 남서해연안 5개 수산자원보호구역(가막만, 여자 만, 득량만, 완도연안, 영광연안) 54개 정점에서 표층 퇴적물을 채취하여 입도, 강열감량(IL), 화학적산소요구량(COD), 산휘발성황화물(AVS) 및 중금속(As, Cd, Cr, Cu, Fe, Hg, Pb, Zn)을 분석하였다. 평균입도(Mz)는 평균 7.4±0.1Ø 였으며, 주로 세립한 니(mud) 퇴적물로 구성되어 있었다. IL, COD와 AVS의 평균농도는 각각 4.63±0.96 %, 13.0±3.1 mgO2/g·dry, 0.092±0.124 mgS/g·dry 였으며, 영광연안이 다른 보호구역에 비해 낮았다. 중금속의 평균농도는 각각 As 7.5±0.9 mg/kg, Cd 0.04±0.02 mg/kg, Cr 70.2±9.7 mg/kg, Cu 15.3±2.8 mg/kg, Fe 3.3±0.5 %, Hg 0.014±0.003 mg/kg, Pb 25.0±6.0 mg/kg, Zn 99±14 mg/kg 였으며, 보호구역내 대부분 만 안쪽에서 높고 만 외측 및 외측연안에서 낮은 특성을 보였다. 퇴적물기준 (sediment quality guidelines, SQGs), 오염부하량지수(pollution load index, PLI), 생태계위해도지수(ecological risk index, ERI)를 사용하여 퇴적물 중 금속 오염도를 평가한 결과, 남서해연안 수산자원보호구역 퇴적물은 수산생물 및 저서생물에 영향을 주지 않는 안전한 중금속 농도를 유지 하고 있었다.
도시지역 합류식 하수배제 설비인 우수받이 및 하수관거, 정화조 등에는 유기성 고형 물이 퇴적되기 쉬우며, 유기성 퇴적물이 부패되는 과정에서 고농도의 황계열 악취물질이 발생한다. 본 연구에서는 전기산화방식을 이용하여 유기성 퇴적물 내에 용존된 악취물질 및 전구물질을 저감시켜, 하수관거에서 기상으로 배출되는 악취 문제를 해결하고자 하였다. 실험실 규모의 밀폐된 회분식 반응기에 하수슬러지(COD 기준 8,000 ~ 28,000 mg·L-1)를 투입하고, 발생되는 악취물질 농도와 악취발생특성을 조사하였다. 여기에 전기산화시스템 을 적용하여 황계열 악취물질과 전체 유기물의 산화 및 분해실험을 진행하였다. 전기산 화 실험을 진행한 결과, 밀폐된 반응기의 기상에서 450 ppm의 고농도로 발생한 황화수 소가 반응 30분 이내에 검출한계 이하까지 제거되었으며, 메틸머켑탄과 디메틸설파이드 는 85% 이상 제거되었다. 투입된 전기에너지당 황계열 악취물질의 제거율은 최대 0.33 mg-S·kJ-1로 나타났다. 또한 1시간의 반응기간 동안 회분식 반응기 내에서 황계열 악취물 질 뿐만 아니라 고농도 퇴적물에 함유된 전체 유기물 농도가 56% 감소하여, 전기산화시 스템이 악취를 유발하는 유기성 전구물질을 동시에 저감하는 효과를 나타내었다. 결과적 으로 최소한의 전기에너지를 이용하여 하수관거 퇴적 유기물에 의한 악취문제를 해결할 수 있을 것으로 기대된다
남해 중앙부해역의 해양환경특성을 파악하기 위해 표층 퇴적물중의 와편모. 조류 시스트와 유기물 분포에 대한 조사를 2002년 4월부터 2003년 1월가지 총 6회 실시하였다. 분석 항목 중 함수율, 강열감량, 화학적 산소요구량, 입자성 유기탄소, 입자성 유기질소, 식물색소량은 각각 38.7~68.9% 3.9~ 12.5%, 9.60~44.05 m9O2 gdry-1, 3.12~13.14mgC gdry-1, 0.49~
To investigate the distribution characteristics of grain size and organic matter of surface sediments from the Nakdong-Goryeong Mid-watershed, surface sediments were collected and analyzed. The samples were collected from six sited at four different times between May 2013 and May 2014. The were analyzed for grain size, water content, ignition loss, chemical oxygen demand, total organic carbon and total nitrogen. The surface sediments were mainly composed of medium sand (mean 44.7%) and coarse sand (mean 32.8%) and became coarser in May 2014. Fine sediments at the site NG-2 were poorly sorted and positively skewed, and occur in a tributary environment that is relatively low-energy compared with the other sites. The water content at the studied sites (15.3 ~ 34.9%) averaged 20.25%, and ignition loss (0.4 ~ 5.8%) and total nitrogen (274 ~ 2493 mg/kg) averaged 1.33% and, 696 mg/kg, respectively. These values indicated that the sediments were not seriously contaminated when compared with the sediment pollution evaluation standard of the National Institute of Environmental Research. The chemical oxygen demand (mean 0.17%) was at the non-polluted level compared with United States Environmental Protection Agency sediment quality standards. The total organic carbon (mean 0.18%) at all sites except site NG-2 (lowest effect level) was the no effect level of the Ontario sediment quality guidelines. The COD/IL (0.02 ~ 0.20) and C/N (0.73 ~ 6.76) were less than 1 and 10, respectively. Organic matter in the study area produced naturally from aquatic organisms. Results of principal component analysis showed that fine sediments (very fine sand and silt) were significantly affected by organic matters (ignition loss, chemical oxygen demand, total organic carbon and total nitrogen). In addition, the highest organic matters content in the study area occurred at the site with the finest sediments (NG-2).
Total organic carbon(TOC), Total nitrogen(TN), and carbon and nitrogen stable isotopes were measured in the sediment and suspended parties in fresh lake water and saline estuarine water to determine the sources of Particulate organic matter(POM) in the sediments of the Youngsan river estuary.
POM in the freshwater discharge water was mostly phytoplankton origin with little trace of terrestrial plants. POM from phytoplankton blooms formed in estuarine water in response to the nutrient enriched freshwater discharges was the most important sources of POM in the sediment near the dike, comprising more than 40% of the total organic matter.
POM from freshwater phytoplankton and oceanic phytoplankton were also important sources of the sediment POM, and their contributions varied with the distances from the dike. Contribution of freshwater phytoplankton to sediment POM decreased from the dike to the outside of the estuary.
독도로부터의 거리 및 수심에 따라 채취된 표층 퇴적물에 대하여 입도분석, 광물분석, 유기물 분석 및 미화석 분석 결과를 이용하여 독도 인근 해저의 퇴적 기작 및 유기 퇴적물의 분포를 규명하였다. 독도 인근 해저 퇴적물은 자갈 및 사질이 우세하며, 끌림에 의한 퇴적 작용이 주를 이루는 반면에 독도와 거리가 멀어짐에 따라 실트와 머드의 비율이 증가하며 점토광물과 장석 등의 광물 성분의 변화를 보이고 뜬짐에 의한 퇴적이 우세해지는 경향을 보인다. 퇴적물에 포함된 유기 퇴적물의 군집 조성 또한 큰 변화를 보이는데, 연안 퇴적물에서는 해양 기원의 유기 퇴적물이, 심해 퇴적물에서는 육상 기원의 유기 퇴적물이 우점한다. 이러한 유기 퇴적물의 군집 변화는 퇴적물의 입도에 큰 영향을 받는 것으로 밝혀졌으며 유기 퇴적물중 높은 화분 농집도는 심해 퇴적물의 유기탄소 함량을 증가시키는데 중요한 역할을 하는 것으로 판단된다.
Surface sediments (0~4 cm) were sampled at 40 stations from Ulsan Bay and its adjacent areas of Korea, to evaluate the contamination by sewage-derived organic matters using fecal sterols. Some sterols were quantified by gas chromatography coupled to mass spectrometry (GC/MS). Total concentrations of eight sterols (coprostanol, cholesterol, cholestanol, epicholestanol, epicoprostanol, β-sitosterol, brassicasterol, and stigmasterol) in the sediments from Ulsan Bay and its vicinity varied from 929 to 23,444 ng/g dry weight. The most predominant sterols were cholesterol and coprostanol, accounting for 33~72% of total sterols. The concentration of coprostanol known as the indicator of human feces ranged from 141 to 8,257 ng/g dry weight. In particular, the coprostanol concentrations in the sediments from Jansaengpo Harbor and Taehwa River exceeded the value of 1,000 ng/g dry weight, suggesting that these areas could be considered as the hot-spot zones by municipal sewage contamination. Some molecular indices and multivariate data analysis were used to assess the origin of these sterols in the sediments. Results showed that the major routes of sewage contamination in Ulsan Bay and its vicinity were the input through Jansaengpo Harbor and Taehwa River.
To utilize coastal aquaculture ground bottom sediment in which concentrations of harmful pollutants are low and organic content is high as an organic fertilizer alkaline stabilizers such as CaO, Oyster shell, Mg(OH)2 were added to the bottom sediment organic additives of livestock or food wastes. Nutritive qualities of crude fertilizers were measured to examine effects of alkaline stabilizers and organic waste additions. The Mg(OH)2-added crude fertilizer had significantly lower total carbon(T-C) and nitrogen(T-N) content, reflecting the dilution effect due to great amount of Mg(OH)2 addition. However, the addition of oyster shell had no significant effect on the T-C and T-N content of the fertilizer. P2O5 and K2O content was considerably higher in the mixed sample of aquaculture ground bottom sediments and livestock wastes than in the mixture of the sediments and food wastes, resulting from higher P2O5 and K2O content in livestock wastes. Addition of Mg(OH)2 increased the content of MgO in the crude fertilizer but significantly reduced the content of other nutritive elements such as P2O5, K2O and CaO. Addition of oyster shell as an alkaline stabilizer seemed to have the advantage of saving time and expenses for dryness due to its role as a modulator of water content. Moreover, additions of effect Mg(OH)2 decreased the concentrations of heavy metals in the fertilizer by the dilution while additions of oyster shell had no influence on heavy metal concentrations in the fertilizer.
갯벌내 미생물에 의한 유기물 분해능력을 조사하기 위하여 환경특성이 다른 세지점의 갯벌을 대상으로 분해능력을 측정한 결과는 다음과 같다.
갯벌의 입도조성은 육상기원 퇴적물의 영향이 상대적으로 큰 만경강과 동진강 하구 갯벌이 하제갯벌보다 전체적으로 입도조성이 작았다.
갯벌의 유기물 분해능력은 초기에는 아주 느리게 일어났으며, 유기물 분해율은 동진강 하구갯벌에서 87.63%, 만경강 하구갯벌에서 86.36%, 하제갯벌에서 85.88%로 나타났고, 시험수 자체의 유기물 분해율은 27.5∼30%로 나타났다.
유기물 분해속도(K')는 동진강 갯벌이 1.364day-1, 만경강갯벌이1.080day-1, 하제갯벌이 0.735day-1로 나타나, 축산폐수의 영향을 많이 받고 유기물함량이 상대적으로 높은 동진강 하구 갯벌에서 높은 유기물 분해속도상수를 나타냈다.
해수중에서의 유기물 분해량을 뺀 순수한 갯벌 미생물에 의해 유기물 분해량은 동진강 하구갯벌이 0.4㎎/g/day, 만경강 하구갯벌이 0.36㎎/g/day 및 하제갯벌이 0.36㎎/g/day로써 평균 0.37㎎/g/day이었다.
단위면적당 유기물 분해량을 계산하기 위해 1ha당 표층 0.1㎝ 에서만 미생물이 작용하고, 갯벌의 비중을 2.5g/㎤으로 가정하여 1ha당 유기물 제거능력을 산출한 결과 9.25㎏/ha로 추정되었다.
갯벌의 유기물 분해속도는 유기물 함량을 간접적으로 나타내는 IL, CODsed, TC와 높은 양의 상관성(R2=0.97∼1.00)을 보였고, 물리적인 특성인 입도와는 입도조성이 작을수록 분해속도가 높게 나타났다.
In an attempt to evaluate the possibility of producing an organic fertilizer using sediments from coastal farming areas, the chemical composition, bacteriological quality and heavy metals in the sediments alkalized by quicklime and magnesium hydroxide were analyzed. The optimum reaction was obtained from the following conditions : a 1:4 mixture of dry sediment to food wastes and the addition of 30% quicklime to the mixture. According to the classification standard for compost constituent by Higgins, all composts had a low or intermediate grade in T-N and K2O content, a low grade in P2O5 and a high grade in CaO and MgO content. Stabilization by quicklime and magnesium hydroxide is likely to inhibit the bacterial decomposition of organic matter and the activity of pathogenic organisms. Raising the pH of stabilized sediments to 12 for 2 hours(PSRP criteria of EPA) allowed 99.99% of the coliform group, fecal group and viable cell count to be reduced. The results suggested that the crude fertilizer produced by alkaline stabilization method was innoxious and thereby the sediments from coastal farming areas could be used as organic fertilizer.
The observations on the seasonal fluctuation and distributional characteristic of organic matters on surface sediments and its origin were carried out at the 25 stations in Keogeum-sudo, southern coast of Korean Peninsula from February to October in 1993. I made an analysis on the environmental factors for surface sediments such as temperature, ignition loss, chemical oxygen demand, pheopigment, total sulphide, water content, mud content in grain size, COD/IL ratio and COD/sulphide ratio.
The results are as follows ;
1) The range of temperature on the surface sediments was between 6.2℃ and 24.6℃. The highest mean temperatuer of mud was 24.0℃ in summer, the lowest 6.6℃ in winter.
2) Ignition loss(IL) fluctuated between 1.2% in winter and 16.8% in spring, that is to say, the seasons of increasing in temperature were very high ignition loss.
3) Chemical oxygen demand(COD) showed the highest mean value of 20.52 ㎎/g dry in summer within the range of 15.46∼32.78 ㎎/g dry, while showed the lowest of 5.79 ㎎/g dry in winter within the range of 7.4∼17.39 ㎎/g dry.
4) Pheopigment concentrations showed the highest mean value of 4.85 ㎍/g dry in autumn within the range of 0.84∼9.21 ㎍/g dry, while it did the lowest mean value of 1.97 ㎍/g dry in summer within the range of 0.23∼4.83 ㎍/g dry.
5) Total sulphide (H2S) fluctuated between no detect(ND) in spring, and 2.43 ㎎/g dry in autumn. The highest mean value was 0.68 ㎎/g dry in autumn, the lowest was 0.16 ㎎/g dry in spring.
6) Water content(WC) and mud content in grain size showed the mean value of 43.2% within the range of 26.5∼59.7% and 91.0% within the range of 57.8∼99.2%, respectively.
7) By the analytical results on the source of organic matter, it had been dumped from the seaweed farms in Keogeum-sudo coastal waters.