• Journal of Ecology and Environment
• /
• v.36 no.1
• /
• pp.73-83
• /
• 2013

The object of this study was to evaluate lotic ecosystem health using multiple eco-metric approaches such as water chemistry diagnosis, physical habitat health evaluations, and biological integrity modeling at 100 streams of four major watersheds. For the study, eight chemical water quality parameters such as nutrients (N, P) and organic material were measured and 11-metric models of Qualitative Habitat Evaluation Index (QHEI) and multiple eco-metric health assessment model (MEHA) were applied to the four major watershed. Nutrient analysis of nitrogen (N) and phosphorus (P) in all watersheds indicated a eutrophic state depending on the locations of sampling streams. Physical habitat health, based on the QHEI model, averaged 114 (range: 56 - 194), judging as a "good condition" by the criteria of Plafkin et al. (1989). In addition, primary (H1 - H4), secondary (H5 - H7), and tertiary habitat metric variables (H8 - H11) were analyzed in relation to the physical habitat degradations. The plots of tolerant species ($P_{TS}$) and sensitive species ($P_{SS}$) to water quality showed that the proportions of $P_{TS}$ had positive linear functions with nutrients, and that the $P_{SS}$ had inverse linear relations with the chemical variables. The model of eco-metric health assessment showed that mean MEHA was 20.4, indicating a fair condition. Overall, our data suggest that water chemistry, based on nutrients and organic matter, directly modified the trophic structures in relation to food chain in the aquatic ecosystems, and then these directly influenced the compositions of tolerance/sensitive species, resulting in degradations of overall ecological health.

• Journal of Ecology and Environment
• /
• v.39 no.1
• /
• pp.61-70
• /
• 2016

Major objectives of the study were to analyze chemical and biological influences of the river ecosystem on the artificial weir construction at three regions of Sejong-Weir (S_j-W), Gongju-Weir (G_j-W), and Baekje-Weir (B_j-W) during 2008-2012. After the weir construction, the discharge volume increased up to 2.9 times, and biological oxygen demand (BOD) and electrical conductivity (EC) significantly decreased (p < 0.05). Also, the decrease of total phosphorus (TP) was also evident after the weir construction, but still hyper-eutrophic conditions, based on criteria by , were maintained. Multi-metric model of Index of Biological Integrity (IBI) showed that IBI values averaged 21.0 (range: 20-22; fair condition) in the B_wc, and 14.3 (range: 12-18; poor condition) in the A_wc. The model values of IBI in S_j-W and G_j-W were significantly decreased after the weir construction. The model of Self-Organizing Map (SOM) showed that two groups (cluster I and cluster II) of B_wc and A_wc were divided in the analysis based on the clustering map trained by the SOM. Principal Component Analysis (PCA) was similar to the results of the SOM analysis. Taken together, this research suggests that the weir construction on the river modified the discharge volume and the physical habitat structures along with distinct changes of some chemical water quality. These physical and chemical factors influenced the ecosystem health, measured as a model value of IBI.

• Journal of Korean Society on Water Environment
• /
• v.26 no.3
• /
• pp.446-453
• /
• 2010

This study was investigated nine nitrosamines in small tributary rivers, sewage treatment plants (STPs) and drinking water treatment plants. They are N-nitrosodimethylamine (NDMA), N-nitrosomethylethylamine (NMEA), N-nitrosodiethylamine (NDEA), N-nitrosopyrrolidine (NPYR), N-nitrosodi-n-propylamine (NDPA), N-nitrosomorpholine (NMOR), N-nitrosopiperidine (NPIP), N-nitrosodi-n-butylamine (NDBA) and N-nitrosodiphenylamine (NDPHA). The nine nitrosamines were analyzed by gas chromatography mass spectrometry (GC/MS) using solid phase extraction (SPE) with a coconut charcoal cartridge. Among the nine nitrosamines, NDMA, NMEA, NDEA, NDPA NDBA and NDPHA were detected in small tributary rivers and sewage tretment plants. In small tributary rivers, NDMA, NMEA, NDEA, NDPA, NDBA and NDPHA were obtained as ND~16.4 ng/L, ND~17.7 ng/L, ND~102.4 ng/L, ND~455.4 ng/L, ND~330.1 ng/L and ND~161.0 ng/L, respectively. Also NDMA, NMEA, NDEA, NDPA and NDBA were investigated ND~821.4 ng/L, 22.5~55.4 ng/L, 53.2~588.5 ng/L, ND~56.6 ng/L and ND~527.9 ng/L in STPs, respectively. In drinking water treatment plants, NMEA and NDEA concentration were increased to as high as 38.8 ng/L after ozonation process. However nitrosamines were decreased subsequent biological activated carbon (BAC) treatment process. It was supposed that nitrosamines were formed by $O_3$ oxidation and were removed by biodegradation of BAC.

• Journal of Korean Society of Water and Wastewater
• /
• v.32 no.2
• /
• pp.159-168
• /
• 2018

Climate change is believed to increase the amount of dissolved organic matter in surface water, as a result of the release of bulk organic matter, which make difficult to achieve a high quality of drinking water via conventional water treatment techniques. Therefore, the natural water treatment techniques, such as managed aquifer recharge (MAR), can be proposed as a alternative method to improve water quality greatly. Removal of bulk organic matter using managed aquifer recharge system is mainly achieved by biodegradation. Biodegradable dissolved organic carbon (BDOC) and assimilable organic carbon (AOC) can be used as water quality indicators for biological stability of drinking water. In this study, we compared the change of BDOC and AOC with respect to pretreatment methods (i.e., ozone or peroxone). The oxidative pretreatment can transform the recalcitrant organic matter into readily biodegradable one (i.e., BDOC and AOC). We also investigated the differences of organic matter characteristics between BDOC and AOC. We observed the decreases in dissolved organic carbon (DOC) and the tryptophan-like fluorescence intensities. Liquid chromatographic - organic carbon detection (LC-OCD) analysis also showed the reduction of the low molecular weight (LMW) fraction (15% removed, less than 500 Da), which is known to be easily biodegradable, and the biopolymers, high molecular weight fractions (66%). Therefore, BDOC consists of a broad range of organic matter characteristics with respect to molecular weight. In AOC, low molecular weight organic matter and biopolymers fraction was reduced by 11 and 6%, respectively. It confirmed that biodegradation by microorganisms as the main removal mechanism in AOC, while BDOC has biodegradation by microorganism as well as the sorption effects from the sand. $O_3$ and $O_3+H_2O_2$ were compared with respect to biological stability and dissolved organic matter characteristics. BDOC and AOC were determined to be about 1.9 times for $O_3$ and about 1.4 times for $O_3+H_2O_2$. It was confirmed that $O_3$ enhanced the biodegradability by increasing LMW dissolved organic matter.

• Journal of Korean Society on Water Environment
• /
• v.26 no.1
• /
• pp.148-155
• /
• 2010

Water quality and plankton community dynamics after the introduction of two domestic freshwater shellfishes (Unio douglasiae Griffith & Pidgeon and Cipangoplaudina chinese malleata Reeve), were monitored daily in enclosures, which constructed in the tidal zone of eutrophic agricultural reservoir (Shingu reservoir, Korea) for one week between July 31 and August 6, 2007. This biomanipulation study to improve the water quality of eutrophic lake, comprised eight enclosures (duplicate x four kinds), enclosure had no mussels (Control), stocked only with U. douglasiae at density of 60 individuals (UD), stocked only with C. chinese malleata at density of 60 individuals (CCM), and combined-stocked with 30 individuals of UD and 30 individuals of CCM (MIX), respectively. Our results clearly indicate that UD strongly decreased the concentration of chlorophyll-a and increased the water transparency, whereas CCM and MIX (included CCM) did increase algal density or decrease transparency, due perhaps to the disturbance of C. chinese malleata. Therefore, the field application of shellfish to enhance the water quality of eutrophic agricultural reservoir, should consider the grazing characteristics of biological control agents, especially active moving animals like snail.

• Journal of Applied Biological Chemistry
• /
• v.42 no.3
• /
• pp.140-145
• /
• 1999

Livestock manure is generally beneficial to soil and crop production when appropriate amount is applied, but excessive application may be detrimental to soil and water environments. A proper protocol of livestock waste treatment is required to manage the quality of soil and water. A trickling filter system using rice straw media was employed to treat piggery wastewater from small-scaled livestock farms as an alternative to the currently available methods. Batches of piggery wastewater were treated with this system, and the byproducts of rice straw media and trickling filtrate were applied to the soil with cultivating rye (Secale cereale L.). Objective of this research was to characterize these byproducts for the sustainable soil amendments and rye production. Both the treated straw medium and filtrate were proven to be effective organic fertilizers for rye plant development, with the enhanced but balanced absorption of nutrients. The synergistic effects of filtrate in addition to straw application did not show, but the filtrate appeared to lead to a higher water content of the plant. No specific nutrient deficiency or toxicity symptom was shown due to the salts derived from the byproducts applied. Chemical parameters of the soil quality were significantly improved with the application of straw medium either with or without the filtrate. Judging from parameters relating to the salt accumulations, such as sodium adsorption ratio (SAR), electrical conductivity (EC), exchangeable sodium percentage (ESP), potassium adsorption ratio (KAR), and residual P concentrations, the byproducts from piggery wastewater exhibited no detrimental effects on soil quality within the ranges of treatments used. In addition to the effectiveness of the rice straw trickling filter system for the small-scaled swine farms, both rice straw medium and filtrate could be recycled for the sustainable soil amendment and plant nutrition.

• Journal of Environmental Impact Assessment
• /
• v.8 no.2
• /
• pp.95-107
• /
• 1999

The organic contents of reservoir sediment can offer a good indicator to events in history of lake life. Reservoir sediment have many information of the past and future fingerprint about development direction of life cycle in biological animals. So, in this study we made an effort to know the distribution of organic contents in Daecheong reservoir sediment. Items for this investigations are such as follows: Loss on ignition, COD, Organic carbon, TN, TP, heavy metal contents, Loss on ignitions were determined in 6.44~15.91% and COD were determined in 1.606~6.859%, organic carbon in 1,077~3.743%. Contents of TP and TN were in the range of 0.083~0.757%, and 0.645~0.926%, respectively.

• Journal of Ecology and Environment
• /
• v.29 no.4
• /
• pp.343-352
• /
• 2006

This study investigated the relationship between land cover and the water quality variables in the rivers, which are located in the Yamaguchi prefecture of West Japan. The study area included 12 catchments covering $5,809\;Km^2$. pH, dissolved oxygen, suspended solid, E. coli, total nitrogen and total phosphorus were considered as river water quality variables. Satellite data was applied to generate land cover map. For linking alterations in land cover (at whole catchment and buffer zone levels) and the river water quality variables, multiple regression modeling was applied. The results indicated that non-spatial attribute (%) of land cover types (at whole catchment level) consistently explained high amounts of variation in biological oxygen demand (72%), suspended solid (72%) and total nitrogen (87%). At buffer zone-scale, multiple regression models that were developed to represent the linkage between the alterations of land cover and the river water quality variables could also explain high level of total variations in suspended solid (86%) and total nitrogen (91%).

• Korean Journal of Ecology and Environment
• /
• v.46 no.3
• /
• pp.343-359
• /
• 2013

In order to understand shoreline environment characteristics of Korean reservoirs, the interrelationships between environmental factors of geomorphology, hydrology, water quality and shoreline soil were analyzed, and the reservoir types were classified according to their environmental characteristics in the 35 reservoirs selected by considering the purpose of dam operations and annual water-level fluctuations. Geomorphological and hydrological characteristics of reservoirs were correlated with the altitude and the size scale of reservoirs. The annual range of water level fluctuation showed a wide variation from 1 m to 27 m in the various reservoirs in Korea. The levels of eutrophication of most reservoirs were mesotrophic or eutrophic. From the result of the soil texture analysis, sand contents were high in reservoir shorelines. Range, frequency and duration of water-level fluctuation were distinctive from the primary function of reservoirs. Flood control reservoirs had a wide range with low frequency and waterpower generation reservoirs had a narrow range with high frequency in the water-level fluctuation. According to the result of CART (classification and regression tree) analysis, the water quality of reservoirs was classified by water depth, range of water-level fluctuation and altitude. The result of PCA (principal component analysis) showed that the type of reservoirs was classified by reservoir size, water-level fluctuation, water quality, soil texture and soil organic matter. In conclusion, reservoir size, the water-level fluctuation, water quality and soil characteristics might be major factors in the environment of reservoir shorelines in Korea.

• Journal of Environmental Science International
• /
• v.9 no.3
• /
• pp.267-273
• /
• 2000

In order to understand the impact for decomposition of blue-green algae Microcystis on water quality, the algae were cultivated with collection of natural population during approximately one month, when water-bloom of Microcystis dominated at August 31, 1999 in the lower part of the Okchon Stream. The enrichment of inorganic NㆍP nutrients didn't in algal assay and the effect of Microcystis on water duality was assessed from the variation of nutrients by algal senescence. Microcystis population seemed to play a temporary role of sink for nutrients in the water body. Initial algal density of Microcystis was 2.3×10/sup 6/ cells/㎖. When Microcystis population died out under light condition, algal NㆍP nutrients between 9∼12 days affected to increase of biomass after reuse by other algal growth as soon as release to the ambient water. However, cellular nutrients under dark condition were almost moved into the water during algal cultivation. NH₄, NO₃ and SRP concentration were highly increased with 160, 17 and 79 folds, respectively relative to the early. As a result, the senescence of Microcystis population seemed to be an important biological factor in which cause more eutrophy and increase of explosive algal development by a lot of nutrients transfer to water body. There are significantly observed an effort of reduce for production of inner organic matters such a phytoplankton as well as load pollutants from watershed in side of the water quality management of reservoir.