• Advances in environmental research
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• 제5권3호
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• pp.169-178
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• 2016

This study aimed at determining the treatability of high-strength wastewater (chemical oxygen demand, COD>4000 mg/L) using combined anaerobic-aerobic granular sludge in lagoon systems. The lagoon systems were simulated in laboratory-scale aerated and non-aerated batch processes inoculated with dried granular microorganisms at a dose of 0.4 g/L. In the anaerobic batch, a removal efficiency of 25% was not attained until the 12th day. It took 14 days of aerobic operation to achieve sCOD removal efficiency of 94% at COD:N:P of 100:4:1. The best removal efficiency of sCOD (96%) was achieved in the sequential anaerobic-aerobic batch of 12 days and 2 days, respectively at COD:N:P ratio of 200:4:1. Sequential anaerobic-aerobic treatment can achieve efficient and cost effective treatment for high-strength wastewater in lagoon systems.

• Asian-Australasian Journal of Animal Sciences
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• 제12권4호
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• pp.629-632
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• 1999

Constructed wetlands are being used for the removal of nutrients from livestock wastewater. However, natural vegetation typically used in constructed wetlands does not have marketable value. As an alternative, agronomic plants grown under flooded or saturated soil conditions that promote denitrification can be used. Studies on constructed wetlands for swine wastewater were conducted in wetland cells that contained either natural wetland plants or a combination of soybeans and rice for two years with the objective of maximum nitrogen reduction to minimize the amount of land required for terminal treatment. Three systems, of two 3.6 by 33.5 m wetland cells connected in series were used; two systems each contained a different combination of emergent wetland vegetation: rush/bulrush (system 1) and bur-reed/cattail (system 2). The third system contained soybean (Glycine max) in saturated-soil-culture (SSC) in the first cell, and flooded rice (Oryza sativa) in the second cell. Nitrogen (N) loading rates of 3 and $10kg\;ha^{-1}\;day^{-1}$ were used in the first and second years, respectively. These loading rates were obtained by mixing swine lagoon liquid with fresh water before it was applied to the wetland. The nutrient removal efficiency was similar in the rush/bulrush, bur-reed/cattails and agronomic plant systems. Mean mass removal of N was 94 % at the loading rate of $3kg\;N\;ha^{-1}\;day^{-1}$ and decreased to 71% at the higher rate of $10kg\;N\;ha^{-1}\;day^{-1}$. The two years means for above-ground dry matter production for rush/bulrushes and bur-reed/cattails was l2 and $33Mg\;ha^{-1}$, respectively. Flooded rice yield was $4.5Mg\;ha^{-1}$ and soybean grown in saturation culture yielded $2.8Mg\;ha^{-1}$. Additionally, the performance of seven soybean cultivars using SSC in constructed wetlands with swine wastewater as the water source was evaluated for two years, The cultivar Young had the highest yield with 4.0 and $2.8Mg\;ha^{-1}$ in each year, This indicated that production of acceptable soybean yields in constructed wetlands seems feasible with SSC using swine lagoon liquid. Two microcosms studies were established to further investigate the management of constructed wetlands. In the first microcosm experiment, the effects of swine lagoon liquid on the growth of wetland plants at half (about 175 mg/l ammonia) and full strength (about 350 mg/l ammonia) was investigated. It was concluded that wetland plants can grow well in at least half strength lagoon liquid. In the second microcosm experiment, sequencing nitrification-wetland treatments was studied. When nitrified lagoon liquid was added in batch applications ($48kg\;N\;ha^{-1}\;day^{-1}$) to wetland microcosms the nitrogen removal rate was four to five times higher than when non-nitrified lagoon liquid was added. Wetland microcosms with plants were more effective than those with bare soil. These results suggest that vegetated wetlands with nitrification pretreatment are viable treatment systems for removal of large quantities of nitrogen from swine lagoon liquid.

• Fisheries and Aquatic Sciences
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• 제22권12호
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• pp.31.1-31.12
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• 2019

Background: The black-chinned tilapia, Sarotherodon melanotheron, is the most abundant fish species in the Nakwa (an open lagoon) and Brenu (a closed lagoon) in the Central Region of Ghana. Aspects of the life history characteristics and the ecology of the fish populations in both lagoons were studied to assess the bio-ecological status of this important resource. Methods: Fish samples were obtained from fishermen that fish on the Nakwa and Brenu lagoons using cast, drag and gill nets. The age of the fish was assessed from otoliths analysis and its growth modelled following the von Bertalanffy growth function. Morphometric characteristics of the fish populations were analysed using power regression and ANOVA for parameters comparisons, and Student's t test to determine whether species grew isometrically. The percentage occurrence method was used to analyse the stomach contents of the fish. Results: A total of 382 fish samples from both lagoons were measured, comprising 209 from Nakwa lagoon and 176 from Brenu lagoon. The size and weight of fish samples ranged between 3.9-11.5 cm total length and 1.0-27.3 g for Nakwa Lagoon and 5.6-12.8 cm total length and 3.2-29.8 g for the Brenu Lagoon. The estimated von Bertalanffy growth parameters were L∞ = 12.04 cm and K = 2.76/year for the Nakwa Lagoon samples and L∞ = 13.44 cm and K = 3.27/year for Brenu Lagoon samples. Daily otolith incremental rate ranged from 0.01-0.03 mm per day to 0.01-0.02 mm per day for Nakwa and Brenu lagoons, respectively. Stomach content analysis of the fish samples revealed that the species are planktivorous and the range of food varied between the lagoons. Green algae were the most prevalent food item in the stomachs of the fish samples from Nakwa with the frequency of 69% whilst diatoms (80.5%) were most prevalent phytoplanktonic food item for the fish in Brenu lagoon. Conclusions: The estimates of asymptotic length for the species in both lagoons are close to known values of the species length at first sexual maturity and points to intensive fishing pressure. As a consequence, a comprehensive sample-based survey is required in both lagoons to derive estimates of management reference points. The results of the stomach content analysis are beneficial to the construction of diet matrix for ecosystem models of the two systems.

• Asian-Australasian Journal of Animal Sciences
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• 제17권8호
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• pp.1168-1176
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• 2004

Intensive animal industries create large volumes of nutrient rich effluent, which, if untreated, has the potential for substantial environmental degradation. Aquatic plants in aerobic lagoon systems have the potential to achieve inexpensive and efficient remediation of effluent, and to recover valuable nutrients that would otherwise be lost. Members of the family Lemnaceae (duckweeds) are widely used in lagoon systems, but despite their widespread use in the cleansing of sewage, only limited research has been conducted into their growth in highly eutrophic media, and little has been 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, although duckweed remained viable and grew sub optimally in media with total ammonia nitrogen (TAN) concentrations of up to 100 mg/l. Duckweed also grew vigorously in effluent diluted 1:4 v/v, containing 56 mg TAN/L and also modified by addition of acid to decrease pH to 7 and by adding bentonite (0.5%).

• Journal of Species Research
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• 제7권2호
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• pp.123-134
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• 2018

A total of 22 bacterial strains belonging to the phylum Bacteroidetes were isolated primarily from aquatic environments such as seawater, freshwater, lagoon and tidal flat. One of these 22 strains was isolated from ginseng soil. Phylogenetic analyses based on 16S rRNA gene sequences revealed that 21 strains showed the high sequence similarities(${\geq}98.7%$) to the closest type strains and formed robust phylogenetic clades with closely related species in the phylum Bacteroidetes. One strain, which had been previously classified as Balneola vulgaris in the phylum Bacteroidetes, was identified as a member of the newly described phylum Rhodothermaeota. These strains had not been previously reported in Korea. Here, we report 21 species of 13 genera in the phylum Bacteroidetes and one species in the phylum Rhodothermaeota which were not reported in Korea. Morphological, biochemical, and physiological characteristics, isolation sources, and NIBR deposit numbers are described in the species descriptions.

• Ocean Systems Engineering
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• 제7권2호
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• pp.75-87
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• 2017

A breakwater has always been an ideal option to prevent shoreline erosion due to wave action as well as to maintain the tranquility in the lagoon area. The effects of the impinging wave on the structure could be analyzed and evaluated by several physical and numerical methods. An alternate approach to the numerical methods in the prediction of performance of a breakwater is Artificial Intelligence (AI) tools. In the recent decade many researchers have implemented several Artificial Intelligence (AI) tools in the prediction of performance, stability number and scour of breakwaters. This paper is a comprehensive review which serves as a guide to the current state of the art knowledge in application of soft computing techniques in breakwaters. This study aims to provide a detailed review of different soft computing techniques used in the prediction of performance of different breakwaters considering various combinations of input and response variables.

• 식물분류학회지
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• 제47권1호
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• pp.51-93
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• 2017

동해안 석호는 해수와 담수가 섞인 독특한 형태의 기수호이며, 수변식생이 발달되어 생물다양성이 풍부한 지역이다. 본 연구는 국내에 분포하는 17개소의 석호에 대한 식물상과 식물 종조성 등의 조사를 통하여 석호 식생에 대한 안정적인 보전계획 수립을 위한 기초자료를 제시하고자 한다. 17개소의 석호에 대한 식물상 조사결과, 관속식물은 118과 378속 655종 13아종 46변종 6교잡종, 총 720분류군이 확인되었다. 이중에서 한반도 고유종이 11분류군, 멸종우려 식물이 18분류군, 식물구계학적 특정식물인 IV-V등급 식물이 23분류 군이었다. 남방계식물은 4분류군, 북방계식물은 8분류군으로 조사되었고, 특히 남한 내 희귀식물인 갯활량나물(Thermopsis lupinoides), 기름당귀(Ligusticum hultenii), 벼룩아재비(Mitrasacme alsinoides), 통발(Utricularia australis), 검정납작골풀(Juncus fauriei), 새방울사초(Carex vesicaria), 천도미꾸리광이(Puccinellia kurilensis) 등이 동해안 석호에서 생육하고 있었다. 외래식물은 96분류군이 발견되었다. 한반도 석호는 식물다양성이 풍부하고, 희귀식물 및 식물지리학적 중요한 식물이 관찰된다. 석호의 효과적인 관리와 생물다양성 보전을 위해 체계적인 사항들이 논의되었다.

• Journal of Species Research
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• 제9권4호
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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.

• Asian-Australasian Journal of Animal Sciences
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• 제17권1호
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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.

• 생태와환경
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• 제34권3호통권95호
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• pp.141-152
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• 2001

1999년 여름동안 동해안의 7개 석호와, 내륙의 5개 인공호를 대상으로 autotrophic picoplankton (APP)의풍부도와 총 식물플랑크톤 생물량에 대한 기여도를 평가하였다. 석호에서는 부영양화가 심한 호수에서 주로 나타나는 phycocyanin-rich APP가 우점한 반면 인공호에서는 주로 phycoerythrin-rich APP가 우점하였다. 동해안 석호에서 APP의 세포밀도와 생물량은 각각 $3.6{\times}10^3{\sim} 5.0{\times}10^6\;cells/ml$와 $1.0{\sim}1,385.0\;{\mu}gC/L$의 범위를 나타냈고 인공호에서는 각각 $3.8{\times}10^4{\sim}3.6{\times}10^5\;cells/ml$와 $15.3{\sim}128.2\;{\mu}gC/L$의 범위로 동해안석호에서 더 높은 APP의 풍부도를 나타냈다. 특히 경포호에서는 3회조사 모두 $10^6\;cells/ml$이상의 높은 세포밀도를 보였는데 이는 세계적으로 보고된 가장 높은 밀도 수준이다. 소양호에서 APP의 수직분포를 조사한 결과 수온약층에서 최대 세포밀도를 나타냈는데 이는 APP가 낮은 광도에서도 성장이 가능하며 심층의 높은 영양염류를 이용할 수 있었기 때문으로 사료된다. APP세포밀도는TN/TP비와 음의 상관관계,TP와는 양의 상관관계를 나타내어 APP의 풍부도가 호수의 부영양화와 함께 증가하는 경향을 나타내었다. 총 식물플랑크톤 생물량에 대한 APP의 기여도는 $0.1{\sim}85.0%$로 호수간의 큰 차이를 보였다. 본 연구결과는 지금까지 식물플랑크톤 연구에서 소외되어져 왔던 APP가 호수 생태계의 일차생산자로써 중요한 부분을 차지하고 있음을 보여주고 있다.