낙동강 중·하류에서 무기 N·P 영양염의 변동

조경제,신재기 ( Kyung Je Cho,Jae Gi Shin ) 한국하천호수학회 1997 생태와 환경 Vol.30 No.2

Inorganic nitrogen and phosphorus were monitored from midstream to downstream, and in the lower part of the Naktong River. Water quality of the Naktong River was deteriorated while the river received high rates of nutrient loadings as the discharge of Kumho tributary, which is located inland 170 km from the estuary. NH_4, NO_3 and SRP concentration were average 4,170㎍ N/l, 1,810㎍ N/l and 246㎍ P/l after Kumho discharge. These leaded to the development and persistence of nuisance algal blooms towards the lower part of Naktong River. Nutrient decreased exponentially and algal biomass increased concurrently from midstream to downstream. Maximum decrease rates (dm) of NH_4, NO_3 and SRP per 10 km distance (approximately one day duration for water flow) from midstream to downstream were average -0.32, -0.03 and -0.33, maximum algal growth rate (㎛) was 0.27, Inorganic N/P ratios ranged 25∼40 in midstream and increased to 100∼270 in the downstream. Phosphorus most likely limited the algal growth over the whole year, viewed with the water analysis and nutrient enrichment bioassay. Algae bloomed bimodally in summer and winter in the lower part of the Naktong River, and inorganic N·P concentration or ratios showed a consistently seasonal variation with the algal bloom. Variation of inorganic N ·P concentration and N/P ratios would be correlated and regulated with allochthonous N ·P loadings or ecophysiological characteristics of blooming algae such as Microcystis and Stephanodiscus population.

마산-진해만의 수질 부영양화 및 계절 변동

조경제,최만영,곽승국,임성호,김대윤,박종규,김영의,Cho, Kyung-Je,Choi, Man-Young,Kwak, Seung-Kook,Im, Sung-Ho,Kim, Dae-Yun,Park, Jong-Gyu,Kim, Young-Eui 한국해양학회 1998 바다 Vol.3 No.4

마산-진해만에서 1996년 1월부터 1997년 8월까지 영양염류, 용존산소, 해수 투명도 등 수질의 부영양화 요인과 식물플랑크톤 생물량의 수직변동, 공간분포 및 계절변동 등을 조사하였다. 식물플랑크톤은 4월부터 10월까지 번무하였으며, 이 기간에는 편모조류가 단독으로 발생하거나 여러 종이 혼합 발생하는 등 매우 역동적인 양상을 보였다. 식물플랑크톤 대발생 시기에는 염분이 감소하였고, 편모조류의 번무로 수색이 변하거나 물의 투명도가 떨어졌다. 여름에 하층은 빈산소상태였으나 상층은 산소의 과포화상태로서 상 하층에 용존산소의 성층화가 형성되었고, 그 구배가 컸다. 반면 겨울에는 영양염류의 수직 분포가 균일하였고, 마산 내만에서 진해 외만에 걸쳐 영양염류의 수평적 구배가 발달하였다. 마산-진해만 수질은 여름에는 저질 퇴적층에서 용출되는 영양염류의 영향을 많이 받았으나, 겨울에는 마산시와 창원시 등 주변 집수역에서 유입되는 오 폐수의 영향을 주로 받는 것으로 추정되었다. 과거 마산-친해만 일원의 수질 분석 자료를 수집하여 마산만 돌섬과 부도 사이의 수질을 연 평균값으로 표준화시킨 결과, COD와 $PO_4$가 비교 가능하였다. 1970년부터 1990년까지 마산만에서 COD와 $PO_4$ 농도는 점진적으로 증가하였으나, 1991년 이후 다소 둔화되거나 감소한 것으로 나타났다. 1991년부터 1994년까지 마산 내만에서 행한 저질 퇴적층의 준설이 이 지역의 수질 악화를 다소 완화시킨 것으로 추정된다. Water quality of Masan-Jinhae Bay was monitored from January 1996 to August 1997. The monitoring focused on the spatial and vertical gradients and seasonal changes of eutrophication parameters such as nutrients, DO and water transparency. Flagellate phytoplanktons persistently bloomed from April to October with monospecific or mixed algal blooms and dynamic algal successions were observed in this area. Algal blooms were highly correlated with salinity drops and made the water less transparent. Stratification of oxygen content was persistent through summer and oligo-oxygenation was developed in the bottom waters. Nutrient gradients were consistently maintained through the depth in summer and through spatial distribution from inner Masan Bay to outer Jinhae Bay in winter. Except the rainfall seasons, water quality was under the influence of the waste waters discharged from watershed around the Masan Bay. The waste waters would act as the primary factor for the water quality deterioration of the bay. Literature data for eutrophication were gathered and analyzed to review the water quality trends of the Masan and Jinhae bays since 1970. Annual mean COD and phosphate concentration consistently increased from 1975 to 1990 and decreased or dropped after 1991. The sediment of inner part of Masan Bay was dredged from 1991 to 1994 as a decontamination process and it is assumed that the dredging has weakened more or less the deterioration trend of the water quality of the bay.

금강 중 ${\cdot}$ 하류에서 AGP에 의한 수질평가

조경제,신재기,Cho, Kyung-Je,Shin, Jae-Ki 한국하천호수학회 2000 생태와 환경 Vol.33 No.3

금강 중${\cdot}$하류의 본류와 지류에서 1998년 3월부터 1999년 6월까지 수질 fertility를 Microcystis aeruginosa의 조류생장잠재력 (AGP)으로 평가하였다. 금강에서는 갑천이 합류되는 지점에서 AGP가 가장 높았고, M. aeruginosa의 AGP는 평균값이 38.1 mg dw/l (17.6${\sim}$75.2 mg dw/l)였다. 또한 조류검정 결과에서 하류로 갈수록 생장이 둔화되어 AGP값이 낮게 나타났고, 이러한 양상은 수질분석 결과와 일치하였다. 지류에서 AGP는 갑천, 미호천 및 석성천이 각각 161.2, 50.3 및 125.6 mg dw/l로서 높았고 유구천이 2.7 mg dw/l로서 최저를 기록하였다. 금강 하류의 수질은 갈수기에 더욱 악화되었고 이 시기에 중류에서 AGP값도 컸다. AGP 결과와 영양염의 관계에서 P와 상관이 가장 높아(r = 0.999) 조류의 생장에 P의 영향이 가장 큰 것으로 추정되었고, 질소원으로는 NO$_{3}$보다 NH$_{4}$가 선호됨을 알 수 있었다. 금강에서 AGP는 장소와 계절에 따라 변화 폭이 컸고 유입 지류의 영양염류 농도 증감과 밀접한 관련성이 있었다. 또한 AGP를 통한 수질상태는 평균값이 32.7 mg dw/l로서 부영양 수준을 훨씬 초과한 것으로 평가되어 이에 대한 수환경관리가 중요하였다. Algal growth potential (AGP) bioassay were conducted to assess the water quality and fertility in the Kum River from March 1998 to June 1999. AGP values were always the highest at the conjuction site of the Kapchon, which is a tributary of the Kum River. Average value of AGP by Microcystis aeruginosa in the main river and tributary was 17.0 mg dw/l, 48.3 mg dw/l, respectively. AGP values decreased towards the lower part of the river and consisted in the water quality or nutrient analysisresults. Among the tributaries, AGP of the Kapchon, Mihochon and Soksongchon were relatively high, and the average value was 161.2, 50.3 and 125.6 mg dw/l, respectively. AGP value in the Yukuchon was lowest among the study stations with <2.7 mg dw/l. Water quality in the lower part of the Kum River deteriorated in drought season, and the AGP values of this season were higher than those in other seasons. Based on correlation analysis between AGP results and nutrients, limiting nutrient appeared to be P because SRP (r = 0.99) was higher than other nutrients, and N uptake in algal growth was preferred by $NH_4$ rather than $NO_3$. The variation of AGP was different according to localities and seasons, and it was related to nutrient fluctuation in the inlet tributary. Water quality status according to AGP was assessed to be eutrophic.

도시근교 하천 조만강의 (潮滿江) 식물플랑크톤 일생산성 추정

조경제,신재기,이진애,문병용 ( Kyung Je Cho,Jae Gi Shin,Jin Ae Lee,Byeong Yong Moon ) 한국하천호수학회 1995 생태와 환경 Vol.28 No.1

Hourly photosynthetic P-I curves were used to estimate the daily production from in situ C-14 data. P^B_(max) were ranged from 1.4 to 7.5(㎍ C/㎍ chl-a/hr) and α ranged from 3.6 to 14.8[㎍ C/㎍ chl-a/(mol/m^2/hr)]. P^B_(max) and α were simultaneously high in the growing season and low in winter. α and I_k were good indicators for seasonally low-irradiance adaptation in algal photosynthesis. At surface high irradiance, photoinhibition didn`t occur and algal assimilation showed a linear or logarithmic decrease along the depth. As water transparency dropped, primary productivity per unit area didn`t increase as production per unit volume did at water surface. Daily productions were estimated from 1.5(g C/m^2/day) at January to 4.0 (g C/m^2/day) at July. The photoadaptation and lack of photoinhibition were reflected by the role of irradiance and water temperature as most significant predictors of daily algal production. Carbon contents of phytoplankton comprised of 33% of particulate organic carbon of water, turn-over rate (P/B) of phytoplankton was 0.61/day and turn-over time was 1.6 day. Choman River, a stagnant and fertilized river near Kimhae city, is characterized by high nutrient loading from the surrounding area and high autochthonous production.

낙동강 담수조류 N·P 요구도 분석을 위한 bioassay

조경제,신재기 ( Kyung Je Cho,Jae Gi Shin ) 한국하천호수학회 1996 생태와 환경 Vol.29 No.4

Fourteen assays for algal N·P demand were conducted in nutrient enrichment bioassay(NEB) using freshwater algae of the Naktong River. P and N+P enrichment stimulated algal biomass(chlorophyll-a) by 1.9 fold and growth rate (㎛) by 1.7 fold, however, NH_4, and NO_3 enrichment had an insignificant effect in comparison with control samples. NH_4 and PO_4 concentration in the media exponentially decreased with the algal growth, on the other side, NO_3 concentration didn`t show any significant decrease on the contrary of the algal exponential growth. Phosphorus was found to be the predominant limiting nutrient to phytoplankton growth. NEB clearly showed primary phosphorus limitation except HWA station (near the mouth of Kumho River Tributary). The Naktong river has been fertilized and highly eutrophicated with nutrient discharge from the Kumho River Tributary. Such nutrient fertility sharply decreased toward the lower part of the river due to the biological uptake. NH_4 was predominantly utilized as the nitrogen source for phytoplankton growth. We concluded that P is the primary limiting nutrient because the Naktong River has the excessive loading and large supplies of ammonia which can be utilized for phytoplankton growth when the water is enriched with P. Considered the N ·P decrease in the culture media as the biological uptake, algal uptakes (㎍ N or P/㎍ chl-a/day) represented 1.1∼8.0㎍ NH_4-N and 0.10∼0.34㎍ PO_4-P respectively. Furthermore, NH_4 ·PO_4 uptake by heterotrophic bacteria were estimated to be 13∼42% and 7∼13% of total uptakes. Bacteria would make profound effects on NH_4 variation in the Naktong River.

낙동강 하류에서 동 하계 무기 N P 영양염류와 식물플랑크톤의 동태

조경제(Kyung Je Cho),신재기(Jae Ki Shin) 한국하천호수학회 1997 생태와 환경 Vol.31 No.1

N/A

상수처리 : 정수장 시설에서 부착조류의 발생현황

조경제 ( Kyung Je Cho ),이지영 ( Ji Young Lee ),최수경 ( Su Kyung Choi ),이옥희 ( Ok Hee Lee ),신재기 ( Jae Ki Shin ) 대한상하수도학회 2003 공동추계 학술발표회 논문집 Vol.2003 No.-

상수처리 : 정수장 시설에서 부착조류의 발생현황

조경제 ( Kyung Je Cho ),이지영 ( Ji Young Lee ),최수경 ( Su Kyung Choi ),이옥희 ( Ok Hee Lee ),신재기 ( Jae Ki Shin ) 한국물환경학회 ( 구 한국수질보전학회 ) 2003 공동 추계학술발표회 Vol.2003 No.-

담수산 Stephanodiscus 속 규조류의 오염지표성 평가

조경제(Kyung Je Cho),신재기(Jae Ki Shin),곽승국(Seung Kuk Kwak),이옥희(Ok Hee Lee) 한국하천호수학회 1998 생태와 환경 Vol.31 No.3

N/A

인공기질을 이용한 부착조류 조사

조경제 ( Kyung Je Cho ) 한국하천호수학회 1994 생태와 환경 Vol.27 No.1

Initial colonization and succession, floral composition and organic matter accumulation(productivity) of the periphytic microalgae were studied in the freshwater zone of the Naktong and Sonaktong River Estuary from November 1991 to March 1993. The periphytons were harvested in the 20-3Ocm and 120-130cm depth under water surface using three artificial substrates such as wood, acryl plate and marble stone. In the initial succession, the yellow-brown unicellular algae and filamentous blue-green algae such as Phormidium and Lyngbya gradually increased and Oedogonium colonized the wood surface secondarily. The weekly organic matter accumulation has a peak during 4th week after substrate settlement and decreased after 4th week. Algal productivity in the upper periphyton community was 20-145㎍ chl/10cm^2 and in the lower community was approximately 12-93% of the upper community. However, organic matter estimated with ash-free dry weight(AFDW) of lower periphyton has 1.1-2.4 folds of the upper periphyton indicating the great mucilage accumulation in lower community. Upper community maintained the diverse microalgae but the lower was predominated with periphytic and planktonic diatoms. Substrate specificity of the diatom flora was not observed except one species, Navicula saprophila, which colonized only the upper part of wood. The floral compositions of periphytic diatom were those of phytoplankton flora. However, blue-green and green algal floras of the periphyton were different from the plankton community.