• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.1
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• pp.62-69
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• 2000

The study was performed to apply the algae removal system to coagulation-filtration process for minimize the damage to screen interruption of water treatment plants and died of fish by algae bloom on freshwater. Sample used Nokdong river water and Alkalinity, turbidity, chlorophyll-a and pH measured using Jar test and drum filter for coagulation-filtration process to determine optimum coagulation condition. A jar test apparatus and laboratory reactor were used in this study. The highest removal efficiency was observed when condition of flocculation time, coagulant dosage, drum filter rpm and chlorophyll-a concentration were to be 5min, 5mg/ℓ, 3rpm and 90㎍/ℓ, respectively. The average removal efficiencies measured of chlorophyll-a and turbidity using Alum were 50～60% and 30～50%, respectively. PAC was more effective than Alum in removal chlorophyll-a about 20%.

• Journal of Environmental Science International
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• v.26 no.2
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• pp.201-210
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• 2017

This study was conducted to estimate the removal efficiency of algae by a mechanical Screw Brush Cone Filter in a lake. The device used a stainless steel cone-shaped filter with a screw brush. The ability of the developed device to remove algae larger than $20{\mu}m$ in Lake ChaSa, Gwangyang city was tested from August to September 2014. The results show that the removal rates for chlorophyll-a, suspended solids and volatile suspended solids were 44-87%(mean 61%), 35-54%(mean 40%), and 37-46%(mean 43%), respectively. This study also discusses equipment and device operation costs and device application problems, and suggests in situ. solutions to these problems.

• Korean Journal of Ecology and Environment
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• v.34 no.2 s.94
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• pp.133-139
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• 2001

For elucidating the effective management for nutrients removal by the phytoplankton growing at the effluents of night soil and sewage treatment plant, the dilution rates, physical operation conditions and duration of culture were defined. For nutrients removal from effluent of night soil treatment plant, lower the dilution was better, and Scenedesmus sp. was dominant. For removal from the effluent of sewage treatMent plant, the proper operation conditions were 50% of dilution rate, stirring and 2 days culturing. With these conditions, the removal rate of TKN was 88%, DIP$70{\sim}80%$ and the chlorophyll concentration reached at $1,300\;mg/m^3$ chlorophyll a concentration. the variation of chlorophyll a was highly corrrlated with ammonia ($r^2\;=\;0.96$) and DIP ($r^2\;=\;0.92$).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.2
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• pp.159-165
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• 1993

To clarify the effects of sink demand for assimilate on leaf photosynthetic rate, tissue composition, and leaf senescence of soybean [Glycine max (L.) Merr.] J plants, pod and leaf tissues were removed at growth stage $R^3$. Plant responses were measured every 10days from 2 through 42days following treatment. Leaves of depodded plants exhibited increased starch and chlorophyll contents and specific leaf weight. Stomatal resistance was also increased and leaf photosynthetic rate was reduced. Dry weight of vegetative tissues except leaves was increased by pod removal. Leaf removal resulted in a decreased starch content of leaves from 22 to 42days after treatment and that of roots at all sampling times. Specific leaf weight was decreased while leaf photosynthetic rate was increased. Stomatal resistance and chlorophyll content were little affected. Weight per seed was decreased 3.0% by leaf removal. Except for the seed, tissue protein contents were increased by pod removal but decreased by leaf removal, however, seed protein content was not affected by either. Apparent senescence was delayed by depodding. Both apparent and functional senescence were accelerated by leaf removal.

• Journal of Nutrition and Health
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• v.52 no.1
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• pp.26-35
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• 2019

Purpose: The aim of this study was to estimate the antioxidant activities of 50%, 70%, and 100% ethanol extracts of Lycium barbarum leaf and chlorophyll removal extract. Methods: The antioxidant activities were estimated by measuring total polyphenol content and by assays of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfate) (ABTS) radical scavenging activities and ferric reducing antioxidant power (FRAP). In addition, reactive oxygen species (ROS) production, DNA fragmentation, and antioxidant enzyme (superoxide dismutase and catalase) activities of the extracts were measured in hydrogen peroxide ($H_2O_2$)-stressed HepG2 cells. Results: The total polyphenol content, DPPH and ABTS radical scavenging activities, and FRAP value of the extracts increased in an ethanol concentration-dependent manner. The antioxidant activities of the chlorophyll-removal extracts were much higher than those of the chlorophyll-containing extracts. Cytotoxicity was not observed in HepG2 cells with extracts up to $1,000{\mu}g/mL$. All extracts inhibited ROS production in a concentration-dependent manner from $31.3{\mu}g/mL$ and inhibited DNA damage at $250{\mu}g/mL$. The SOD and catalase activities of cell lines treated with the extracts and $H_2O_2$ were similar to those of normal cells, indicating a strong protective effect. Conclusion: Lycium barbarum leaf extracts had high antioxidant activities and protected $H_2O_2$-stressed HepG2 cells. Since the chlorophyll-removal extract exhibited higher antioxidant activities than the chlorophyll-containing ones and the cytoprotective effect was similar, chlorophyll removal extract of Lycium barbarum leaf could be developed as ingredients of functional food and cosmetics.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.279-289
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• 2000

The objective of this study was to investigate the effect of coagulants and solid-liquid separation methods on algal removal in water treatment processes. Thus characterization of raw water quality in terms of turbidity. UV-254, $KMnO_4$ consumption, chlorophyll-a and correlation analysis of these parameters were conducted. In addition, the effect of commercial Al-based coagulants(Alum. PAC and PACS) on algal removal was studied by turbidity and organic removal, algal species removal, characteristic of pH drop and alkalinity consumption using laboratory jar tests. Organic components including UV-254, $KMnO_4$ consumption, chlorophyll-a in case of algal bloom were highly correlated with turbidity and the correlation coefficients of UV-254, $KMnO_4$ consumption, chlorophyll-a with turbidity were 0.775, 0674 and 0.623, respectively. In coagulation and sedimentation, the Al-based coagulants showed similar efficiency of organic and turbidity removal in low organic($KMnO_4$ consumption below 15mg/l) and low turbidity(below 30NTU). However, PAC and PACS showed better algal removal than alum in high organic concentration($KMnO_4$ consumption above 20mg/l) and high turbidity(above 100NTU) raw water conditions generated by high algal growth, which is considered to be due to the floc settleability. In comparison of sedimentation and flotation after chemical coagulation and flocculation, the removal efficiency of organic and turbidity were higher in case of alum dose with flotation than with sedimentation, while those were better in case or PAC and PACS with sedimentation than with flotation. Thus, Alum with flotation and PAC and PACS with sedimentation is recommended for efficient algal removal. The dominant phytoplankton in raw water were Microcystic and pediastrum simplex and the removal efficiency of algae with sedimentation using alum. PAC and PACS were 27%, 45% and 22% respectively, while those with DAF showed 100% removal of phytoplankton and zooplankton.

• Journal of Environmental Science International
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• v.11 no.12
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• pp.1267-1274
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• 2002

This study was carried out to evaluate the pollutant removal efficiencies of the advanced drinking water treatment using ozonation process. For raw water, Nakdong River was used. By conducting batch test of ozonation, the following results were obtained. When ozone dosage of $5 mg/{\ell}$ was used, ozone transfer and utilization efficiencies of the ozonation were 94 to 92%, respectively. Removal efficiencies of single VOC compound or mixed VOC compounds in the raw water were 80% to 90% by the ozonation with $2 mg/{\ell}$ dosage and 10 minutes contact time. Removal efficiencies of ABS by the ozonation with $1 mg/{\ell}$, $3 mg/{\ell}$ dosage and 20 minutes contact time were 83% to 96%, respectively. Almost 67% of chlorophyll-a at the concentration of $38.4\mu\textrm{g}/{\ell}$ was removed by ozonation at ozone dosage of $1 mg/{\ell}$ for 20 min. Considering the efficiency of ozone utilization and water treatment, the most effective ozonation could be obtained with high ozone dosage and short contact time.

• Journal of Marine Life Science
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• v.2 no.2
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• pp.49-55
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• 2017

Four chemical treatments with hydrogen peroxide (H₂O₂), copper sulfate (CuSO₄), potassium permanganate (KMnO₄) and chlorine (Cl₂) were applied to the effluent pond water of a hybrid striped bass saltwater recirculating aquaculture system to compare their oxidation power. Four chemicals were applied at concentrations of 0 (control), 1, 5, 10 and 20 mg/l. An additional concentration of 40 mg/l was included in the chlorine treatment. Water samples from four hybrid striped bass ponds were tested with KMnO₄ and Cl₂. H₂O₂ did not reduce any of BOD, COD and chlorophyll-a, and copper sulfate was only effective on chlorophyll-a for the effluent pond. Removal efficiencies for chlorophyll-a by copper sulfate were 19.2%, 37.5%, 54.2% and 74.1% dose-dependently. Potassium permanganate effectively removed the BOD, COD and chlorophyll-a. The COD removal rates in four fish ponds varied from 15.9% to 31.6% at the concentration of 10 mg/l. Interestingly, Cl₂ did not reduce the BOD and COD at all, but the BOD and COD instead increased drastically with increasing the Cl₂ concentration. The pond water with the highest initial BOD and COD values among the fish ponds tested increased by 350% in the BOD and 150% in the COD at 20 mg/l. Furthermore, Cl₂ did not significantly reduce any types of solid matter in this study, while KMnO₄ seemed to reduce some extent volatile dissolved solid in the fish pond.

• Journal of Environmental Science International
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• v.18 no.3
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• pp.289-298
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• 2009

The blue-green algae which caused odor problem in the tap water are difficult to precipitate in sedimentation basin and clogged the filter void rapidly. The studies of this paper were not only oxidation, coagulation and sedimentation processes for effectively removing blue-green algae but yellow clay and polyamine for verification as coagulants aids. The results of this research are summarized as follows: Higher ozone dose(C) and longer contact time(T) were needed for a high degree of removing blue-green algae efficiency. the removal rate of blue-green algae was proportional to the $C\times T$ value. The removal percent of chlorophyll-a by sedimentation and filter without pre-ozonation was about 75% but 1 mg/L pre-ozonation could increase the removal percent of chlorophyll-a to 99% and more pre-ozonation could remove completely. Though the removal efficiency of turbidity could increased by high dose of chlorination, the dissolved organic carbon was increased. More chlorine dose from 4 to 10 mg/L dissolved organic carbon was decreased. Using yellow clay as coagulant aids increased density of floc so the settling velocity of floc become rising but polyamine could not increase settling velocity of floc though it could formated large floc.

• Environmental Engineering Research
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• v.18 no.4
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• pp.235-239
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• 2013

In the present investigation, the efficiency of Chlorella vulgaris (C. vulgaris) was evaluated for the removal of ammonia-nitrogen from wastewater. Eight different wastewater samples were prepared with varied amounts of $NH_4-N$ concentrations from 15.22 to 205.29 mg/L. Experiments were conducted at pH $7.5{\pm}0.3$, temperature $25^{\circ}C{\pm}1^{\circ}C$, light intensity $100{\mu}E/m^2/s$, and dark-light cycles of 8-16 hr continuously for 8 days. From the results, it was found that $NH_4-N$ was completely removed by C. vulgaris, when the initial concentration was between 5.22-25.24 mg/L. However, only 50% removal was obtained when the $NH_4-N$ concentration was 85.52 mg/L, which further decreased to less than 32% when the $NH_4-N$ concentration exceeded 105.43 mg/L. The further influence of nitrogen on chlorophyll was studied by various $NH_4-N$ concentrations. The maximal value of chlorophyll a (Chl a) content was found to be 19.21 mg/L for 65.79 mg/L $NH_4-N$ concentration, and the maximum specific $NH_4-N$ removal rate of 1.79 mg/mg Chl a/day was recorded at an $NH_4-N$ concentration of 85.52 mg/L. These findings demonstrate that C. vulgaris could potentially be employed for the removal of $NH_4-N$ from wastewater.