• Environmental Analysis Health and Toxicology
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• v.28
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• pp.17.1-17.3
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• 2013

The fact that hazardous metals do not bio-degrade or bio-deteriorate translates to long-lasting environmental effects. In the context of evidently rapid global industrialization, this ought to warrant serious caution, particularly in developing countries. In the Republic of Fiji, a developing country in the South Pacific, several different environmental studies over the past 20 years have shown levels of lead, copper, zinc and iron in sediments of the Suva Harbor to be 6.2, 3.9, 3.3 and 2.1 times more than the accepted background reference levels, respectively. High levels of mercury have also been reported in lagoon shellfish. These data inevitably warrant thorough assessment of the waste practices of industries located upstream from the estuaries, but in addition, an exposure and health impact assessment has never been conducted. Relevant government departments are duty-bound, at least to the general public that reside in and consume seafood from the vicinities of the Suva Harbor, to investigate possible human effects of the elevated hazardous metal concentrations found consistently in 20 years of surface sediment analysis. Furthermore, pollution of the intermediate food web with hazardous metals should be investigated, regardless of whether human effects are eventually confirmed present or not.

• Journal of Environmental Science International
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• v.24 no.9
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• pp.1101-1121
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• 2015

The seasonal variation of phytoplankton communities and its standing crops in accordance with environmental factors were investigated at Yeongrang-ho, Cheongcho-ho, Mae-ho and Hyang-ho which are located in the East coast of Korea during April to October 2011. High concentrations of T-N and T-P were observed in four lagoons due to the inflowing nutrients from farmlands and residential areas near lagoons. Nutrient salts mainly composed of nitrogen and phosphate caused the eutrophication of the lakes, leading to the robust growth of phytoplankton. During the period of investigation, 64 to 107 taxa of phytoplankton were observed in four lagoons. Diatoms were the most dominant species with high density. Non-point pollution source was estimated as the main cause of water pollution of lagoons. Trophic states of lagoons evaluated using the value of TSI and TSIKO indicated that all the investigated lagoons were in the eutrophication state.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.257-264
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• 2003

Bulking change between sediments and dredged soils occurs when dredged soils are fully disturbed by dredging process and settled down to stabilized conditions in the basin. Bulking of dredged soils are affected by chemical injection, coagulant and flocculant, to speed up settling process of the suspended solids. In this paper, bulking changes of dredged soils are investigated by experimental works regarding injection effects of the coagulant and flocculant. Dredged sediments were sampled in the lagoon located at the East Coast, and the bulking change of dredged soils is quantitatively analysed by changing the clay content and the amount of the coagulant and flocculant. The optimal amounts of the coagulant and flocculant are determined based on minimal bulking change due to coagulant and flocculant injection. From the experimental results, the bulking of dredged soils increased 1.69 times on the average and the bulking change rate slightly increased as clay content increasea due to injection of the coagulant and flocculant.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.1
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• pp.137-145
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• 2004

Intensive animal industries create large volumes of nutrient rich effluent which, if untreated, has the potential for substantial environmental degradationand to recover valuable nutrients that would otherwise be lost. Members of the family Lemnaceae are widely used in lagoon systems, to achieve inexpensive and efficient remediation of effluent. Only limited research has been conducted into their growth in highly eutrophic media and there has been little done to systematically distinguish between different types of media. This study examined the growth characteristics of duckweed in abattoir effluent and explored possible ways of ameliorating the inhibitory factors to growth on this medium. A series of pot trials was conducted to test the tolerance of duckweed to abattoir effluent partially remediated by a sojourn in anaerobic fermentation ponds, both in its unmodified form and after the addition of acid to manipulate pH, and the addition of bentonite. Unmodified abattoir effluent was highly toxic to duckweed, even at dilutions of 3:1. Duckweed remained viable and grew sub-optimally in simplified media with total ammonia nitrogen (TAN) concentrations of up to 100 mg/L. Duckweed grew vigorously in effluent diluted 1:4 v/v, containing 56 mg TAN/L when modified by addition of acid (to decrease pH to 7) and bentonite at 0.5%. The results of this study suggest that bentonite plays an important role in modifying the toxicity of abattoir effluent to duckweed.

• The Korean Journal of Quaternary Research
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• v.15 no.2
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• pp.83-91
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• 2001

The environmental change during the upper Holocene was restored at Kimpo alluvial plain on the left bank of Han-river near the Yellow Sea according to the results of pollen analysis and carbon dating, based on the sea-level change from Ilsan area. Pollenzone I (5.8~7.0 m.a.s.l.) was the period of AP-dominance, including mostly Alnus. Study area was under the lagoon or swamp environment influenced by Flandrian transgression during 5,000~3,200 BP. Pollenzone II (7.0~7.4 m.a.s.l.) was the period of Spore & NAP-dominance. It represents that the vegetational environment was changed to drier condition by falling underwater surface caused by sea-level regression, and influenced by human activity during 3,200~2,300 BP. Subzone I a represented the characteristics of the climax of transgression. During subzone I b, herbs with the dominant Alnus were increased gradually, and it was correlated to the stagnation of high sea-level. Subzone II a was the dominant period of Spore by the gradual falling of sea-level. After that, the study area in swamp was emerged to the lowland by the fallen sea-level and herbs, especially Gramineae increased suddenly during Subzone II b. The sudden increase of NAP such as Artemisia, Chenopodiaceae and Umbelliferae with Gramineae during this period indicates the beginning of agriculture at this study area.

• Journal of Animal Science and Technology
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• v.53 no.6
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• pp.549-561
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• 2011

Livestock wastewater is being discharged without treatment from Hasen's pig farm cluster in WangGoong (WG) area into the Iksan Stream, eventually flowing into the ManGyung (MG) at the upstream junction. Although it is well known that before discharge, wastewater must satisfy the pig slurry discharge standards; because of ongoing remodeling, proper treatment is not being performed. According to public records, wastewater from the WG pig farm cluster is responsible for 3.6% of MG River pollution and 2.0% of the SaeManGuem (SMG) Reservoir pollution. As a result, upstream water treatment quality has become primary concern for development of the SMG project. All physicochemical constituents and pathogenic microbes, such as chemical oxygen demand ($COD_{Cr}$), biochemical oxygen demand ($BOD_5$), total suspended solids (TSS), total nitrogen (TN), total phosphorous (TP), fecal coliforms, Escherichia coli and Salmonella at the effluent of WG Plant (S-1) exceed the effluent standards. This is mainly due to insufficient wastewater treatment: the WG Plant is under renovation to increase water purification efficiency. By comparing the water quality at the S-7 junction, where the the Iksan Stream (pig farms) and the Wanggoong Stream (no pig farms) merge, it is clear that farming facilities and improper treatment can critically affect surrounding water quality. While it is clear throughout this study that the level of all physicochemical parameters and pathogenic microbes along the Stream decreased due to sedimentation, biodegradation and/or dilution. An alarming problem was discovered: the existence of pathogenic microbe count(E coli, Salmonella) in the lagoon wastewater and the stream water. Not only were high concentrations of these pathogens themselves found, but the potential existence of more serious pathogens could rise to more dangerous conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.3114-3119
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• 2013

The mangrove ecosystems have the capacity to act as a sink of heavy metals entering aquatic ecosystems. Despite their potential exposure to metal contaminated sediments, mangroves appear to be highly tolerant to heavy metals. In this study, we cloned metal tolerance gene from mangrove plant. Using CTAB method, RNA were isolated from leaves and root tissue of Rhizophora stylosa habitated at Weno island in Micronesia Chuuk lagoon using CTAB method and phytochelatin synthase 1 (PCS1) gene was cloned using gene specific primers. Expression of PCS1 gene was increased 1.91 fold and 2.72 fold in mangrove propagules exposed to 100 ppb Cd and 10 ppb Cu, respectively. These results indicate that expression of PCS1 gene are promising tools for health assessment of mangrove ecosystem.

• Journal of Species Research
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• v.9 no.4
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• pp.346-361
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• 2020

In the project of a comprehensive investigation of indigenous prokaryotic species in Korea, a total of 39 bacterial strains phylogenetically belonging to the classes Betaproteobacteria and Gammaproteobacteria were isolated from various environmental sources such as soil, cultivated soil, sludge, seawater, marine sediment, algae, human, tree, moss, tidal flat, beach sand and lagoon. Phylogenetic analysis based on 16S rRNA gene sequences revealed that 39 strains showed the high sequence similarities (≥98.7%) to the closest type strains and formed robust phylogenetic clades with closely related species in the classes Betaproteobacteria and Gammaproteobacteria. In the present study, we report 14 species of 9 genera of four families of two orders in the class Betaproteobacteria and 25 species of 21 genera of 15 families of eight orders in the class Gammaproteobacteria, which have not been reported in Korea. Morphological, biochemical, and physiological characteristics, isolation sources, and NIBR deposit numbers are described in the species descriptions.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.211-216
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• 2006

Within the frame of the MERCOSUR (South Common Market), one of the most important goals to achieve by its member states is a better cost effective international cargo transportation system. For this purpose the project of developing a commercial waterway linking the east region of Uruguay with the south of Brazil has been under study for a number of years now. Because of the high costs involved on the development of such waterway, the project has been indefinitely delayed. It is our intention to show an alternative way to reduce the present obstacles by using a budget oriented approach in order to determine the vessel best suited to use on the proposed waterway. So far, every study related to the project has been focused on the amount of work needed to modify the environment in order to accommodate the hardware already available in the region. The conclusions show that the cost of opening and maintaining the required navigation channel is high enough to discourage investment; the added responsibility to take care of any environmental damage incurred during the building and/or operation of the waterway makes searching for a less costly and hazardous option an interesting challenge. The proposed terminal on the Cebollat? River would be located at the heart of the Uruguayan rice growing region. Uruguay exports 90% of its rice production, being Brazil its biggest buyer. Wood chips and clinker are the other types of cargo considered to use the proposed waterway in route to either Brazil or to overseas destinations through the deep water port of Rio Grande. Through the analysis of local data by a Geographical Information System, international regulations regarding inland waterways and shallow draught vessel characteristics, we seek to propose a cost efficient alternative to apply on this particular scenario.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.92-98
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• 2013

Microalgal cultivation using wastewater is now regarded as essential for biodiesel production, as two goals can be achieved simultaneously; that is, nutrient removal efficiency and biomass production. Therefore, this study examined the effects of carbon sources, the N:P ratio, and the hydraulic retention time (HRT) to identify the optimal conditions for nutrient removal efficiency and biomass production. The effluent from a 2nd lagoon was used to cultivate microalgae. Whereas the algal species diversity and lipid content increased with a longer HRT, the algal biomass productivity decreased. Different carbon sources also affected the algal species composition. Diatoms were dominant with an increased pH when bicarbonate was supplied. However, 2% $CO_2$ gas led to a lower pH and the dominance of filamentous green algae with a much lower biomass productivity. Among the experiments, the highest chlorophyll-a concentration and lipid productivity were obtained with the addition of phosphate up to 0.5 mg/l P, since phosphorus was in short supply compared with nitrogen. The N and P removal efficiencies were also higher with a balanced N:P ratio, based on the addition of phosphate. Thus, optimizing the N:P ratio for the dominant algae could be critical in attaining higher algal growth, lipid productivity, and nutrient removal efficiency.