• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.238-246
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• 2016

Water purification facilities utilizing three technologies - a detention pond, an artificial wetland and an ecological revetment - were installed in waterfront spaces, including river embankments and watersides that have so far been left neglected, and then their water purification levels were analyzed in this study. The water purification facilities were found to show average removal efficiencies of 48.6% in suspended solid (SS), 30.5% in biochemical oxygen demand (BOD), 18.4% in total nitrogen (T-N) and 27.3% in total phosphorus (T-P) during rainfall. The removal efficiencies during non-rainfall were 33.2% in SS, 28.6% in BOD, 13.7% in T-N and 17.3% in T-P. These results showed that the water purification facilities using a detention pond, an artificial wetland and an ecological revetment can be used as a useful natural water purification technology in in waterfront spaces.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.131-138
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• 2014

While coupling wastewater treatment with microalgal bioenergy production is very promising, new approaches are needed to enhance microalgal growth and lipid accumulation in wastewater. Therefore, this study investigated the effect of iron on the growth, nutrient removal, and lipid accumulation of Scenedesmus sp. LX1 in both artificial wastewater and domestic secondary effluents. When increasing the iron concentration from 0 to 2 mg/l in the artificial wastewater, the biomass production of Scenedesmus sp. LX1 increased from 0.17 to 0.54 g/l; the nitrogen and phosphorus removal efficiency increased from 15.7% and 80.6% to 97.0% and 99.2%, respectively; and the lipid content was enhanced 84.2%. The relationship between the carrying capacity/maximal population growth rate of Scenedesmus sp. LX1 and the initial iron concentration were also in accordance with the Monod model. Furthermore, when increasing the iron concentration to 2 mg/l in four different domestic secondary effluent samples, the lipid content and lipid production of Scenedesmus sp. LX1 was improved by 17.4-33.7% and 21.5-41.8%, respectively.

• Environmental Engineering Research
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• v.24 no.2
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• pp.238-245
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• 2019

This study investigated the characteristic of aerobic granular sludge (AGS) process to treat the sewage having low carbon/nitrogen ratio (Biochemical oxygen demand ($BOD_5$):Total nitrogen (T-N), 4.5:1) in sequencing batch reactor (SBR). The removal efficiency of $BOD_5$, suspended solid (SS), T-N and phosphorus ($PO_4{^{3-}}$-P) were 92.6%, 64.3% and 90.1%. Concentration and size of AGS were changed in proportion to the organic matters and nitrogen concentration of the influent (Concentration and size of AGS: 1,700-3,000 mg/L, 0.5-1.0 mm). Mixed liquor suspended solid (MLSS) also changed with the concentration of AGS (MLSS: 2,000-3,500 mg/L). When the settling time was shortened from 15 min to 10 min, size and shape of AGS were maintained (Size of AGS: 1.0-1.5 mm). In addition, the concentration of AGS and MLSS increased (Concentration of AGS: 3,500 mg/L, MLSS: 4,000 mg/L). Concentration, size and shape of AGS were affected the settling time of the reactor more than the concentration of organic matter and nitrogen in the influent. In the results of removal efficiency and changes in AGS, we confirmed that the SBR process using AGS can be used to treat the sewage having low carbon/nitrogen ratio by applying short settling time.

• Clean Technology
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• v.25 no.3
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• pp.231-237
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• 2019

The BOD removal efficiency according to HRT of the continuous inflow SBR process was decreased from 92.1 ~ 96.0% at HRT 9 ~ 15 h to 86.9 ~ 90.7% at HRT 6 h, but a stable removal efficiency was shown up to HRT 6 h. The T-N removal rate was decreased to 80.1 ~ 87.9% at HRT 12 ~ 15 h, to 71.9 ~ 87.0% at HRT 9 h, and to 60.1 ~ 65.7% at HRT 6 h. As a result of the test of removing organic matter and nitrogen, the optimum HRT of the continuous inflow SBR reactor is determined as 9 h. The TCODcr removal efficiency was 88.4 ~ 96.0% and the TBOD removal efficiency was 92.1 ~ 98.1% as a result of examination of organic matter removal efficiency according to a change in the recycling rate (1 ~ 5Q) at HRT 9 h, suggesting that the a change in the recycling rate has a minimal effect on the removal of organic matter. The T-N removal efficiency was 70.3 ~ 80.4% at 1 ~ 2Q, 77.2 ~ 85.6% at 3Q and 61.5 ~ 80.8% at 4 ~ 5Q according to a change in the recycling rate. The TP removal efficiency was reduced to 75.0 ~ 84.6% at 1 ~ 4Q and to 63.3 ~ 72.4% at 5Q. This is presumably because the release and ingestion of phosphorus (P) by microorganisms is not performed smoothly at 5Q or more. Therefore, the optimum recycling rate for removing organic matter and nutrients was found to be 3Q.

• Journal of Animal Science and Technology
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• v.49 no.2
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• pp.161-170
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• 2007

A submerged biofilm sequencing batch reactor (SBSBR) process, which liquor was internally circulated through sandfilter, was designed, and performances in swine wastewater treatment was evaluated under a condition of no external carbon source addition. Denitrification of NOx-N with loading rate in vertical and slope type of sandfilter was 19% and 3.8%, respectively, showing approximately 5 times difference, and so vertical type sandfilter was chosen for the combination with SBSBR. When the process was operated under 15 days HRT, 105L/hr.m3 of internal circulation rate and 54g/m3.d of NH4-N loading rate, treatment efficiencies of STOC, NH4-N and TN (as NH4-N plus NOx-N) was 75%, 97% and 85%, respectively. By conducting internal circulation through sandfilter, removal performances of TN were enhanced by 14%, and the elevation of nitrogen removal was mainly attributed to occurrence of denitrification in sandfilter. Also, approximately 57% of phosphorus was removed with the conduction of internal circulation through sandfilter, meanwhile phosphorus concentration in final effluent rather increased when the internal circulation was not performed. Therefore, It was quite sure that the continuous internal circulation of liquor through sandfilter could contribute to enhancement of biological nutrient removal. Under 60g/m3.d of NH4-N loading rate, the NH4-N level in final effluent was relatively low and constant(below 20mg/L) and over 80% of nitrogen removal was maintained in spite of loading rate increase up to 100g/m3.d. However, the treatment efficiency of nitrogen was deteriorated with further increase of loading rate. Based on this result, an optimum loading rate of nitrogen for the process would be 100g/m3.d.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.82-92
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• 2020

Since swine wastewater contains high concentrations of nutrients and heavy metals, it deteriorates water quality when discharged. Compared to conventional methods, bioremediation can be a promising method for its treatment. Specifically, microalgae have the potential to remove these pollutants. In this study, the removal of nutrients (nitrogen (N) and phosphorus (P)) and heavy metals (copper (Cu) and zinc (Zn)) from swine wastewater by Ankistrodesmus bibraianus was evaluated and the organism's optimal growth conditions were investigated. The optimal growth conditions were established at 28℃, pH 7, and light and dark cycles of 14:10 h. The removal efficiencies of N and P by a single treatment (500, 1,000, 5,000, and 10,000 mg L^-1) ranged from 22.9 to 80.6% and from 11.9 to 50.0%, respectively. The removal efficiencies of N and P in the binary treatments ranged from 16.4 to 58.3% and from 7.80 to 49.8%, respectively. The removal efficiencies of Cu and Zn by a single treatment(10, 30, and 50 mg L^-1) ranged from 15.5 to 81.5% and from 6.28 to 34.3%, respectively. Similarly, the removal efficiencies of Cu and Zn in the binary treatments ranged from 16.7 to 74.5% and from 5.58 to 27.5%, respectively. In addition, the study showed the optimal growth conditions for microalgae and the removal efficiency of nutrients (N and P) and heavy metals (Cu and Zn), which could be applied to swine wastewater. Based on the results in this study, it appears that Ankistrodesmus bibraianus could be used for the removal of nutrients and heavy metals present in swine wastewater.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.5
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• pp.87-94
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• 2009

The objectives of this paper were to estimate cell based pollutant loadings for total maximum daily load (TMDL) programs and to evaluate the applicability of the agricultural nonpoint source (AGNPS) model for an intensive agricultural watershed in Korea. The model was calibrated and validated at a watershed of 384.8 ha of drainage area using the observed data from 1996 through 2000 in terms of runoff, suspended solid, total nitrogen, and total phosphorus on a hourly basis. Analysis of spatial variations of pollutant loadings for rainfall frequencies of various intensities and durations were conducted. In addition, the validated model was applied to estimated the TMDL removal efficiency for best management practices (BMPs) scenarios which were selected by taking into account the pollutant characteristics of the study watershed. The model can help to understand the problems and to find solutions through landuse changes and BMPs. Thus, the method used for this study was able to identify TMDL quantitatively as well as qualitatively for various sources pollution that are spatially dispersed. Also it provides an assessment of the impact of BMPs on the water bodies studied, allowing the TMDL programs to be complemented more effectively.

• Journal of Environmental Science International
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• v.14 no.9
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• pp.873-879
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• 2005

This study was investigate to evaluate the phosphate uptake rate of green algae in relation to diurnal rhythm and algae control method. The phosphate uptake rates of Chlorella vulgaris and Ankistrodesmus convolutus increased in light period and decreased in dark period. On the contrary, those of Chlamydomonas sp. showed a peak in the late dark period. The differences among species in phosphate uptake in relation to diurnal rhythm were due to the severe competition among species and seemed to alleviate the competition for nutrient supplies. The compound of CellCaSi, Ca and Fe showed the effective removal of the phosphorus. The extracts from rice and barley straw exhibited a significant effect on the growth inhibition of Microcystis aeruginosa.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.3-14
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• 2008

ASM No. 2(Activated sludge model No. 2) is very useful model to analyze the wastewater treatment which removes nitrogen and phosphorus. But, it is difficult to apply ASM No. 2 to control of wastewater treatment since it has 17 material divisions and 46 parameters. So the purpose of this study was the simplification of ASM No. 2 and the provement of simplification model. Firstly ASM No. 2 was simplified with 5 material division and three phases(Anaerobic, aerobic, anoxic phases). The simplified model was proved by R-square using track study data. As a result of provement, the values of R-square in ${NH_4}^+$ were 0.9815 in ASM No. 2 and 0.9250 in simplified model and in ${NO_3}^-$ were 0.8679 in ASM No. 2 and 0.7914 in simplified model and in ${PO_4}^{3-}$ are 0.9745 in ASM No. 2 and 0.9187 in the simplified model when the ability to express the material variation was compared by R-square. So, the simplified model has enough ability to express the variation of ${NH_4}^+$, ${NO_3}^-$ and ${PO_4}^{3-}$.

• Journal of the Korean Society of Food Culture
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• v.7 no.4
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• pp.339-362
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• 1992

The Guk was divided Malgunjangguk, Tojangguk, and Gooumguk as to cooking method. Gooumguk was boiled with several materials of beef, bone, organs and water for the long time, and a good source of protein, calcium, and phosphorus. In the thesis, according to the kinds of Gooumguk, the reference frequency to them, the adding foods in them, and the variety cooking method in the Gooumguk were analyzed by the cooking books published from 1670 to 1988 in Korea. 1. There were 41 kinds of Gooumguk and Kaejang, Joktang and Byultang were firstly published to Omshikdimibang in 1670. 2. Many kinds of Gooumguk were generally used on royal parties in Yi dynasty and were used by several substances. 3. The main substances of Gooumguk were meat, poultry, fish, and shellfish. The seasoning substances were green onion, garlic, ginger and black pepper etc, and were used for the removal of the meat's or fish's off-flavor. 4. Yangtang, Kalbitang, Joktang, Yeongebacksuk, and Chooatang etc expressed the taste of the one main substance and Japtang, Sulnongtang, Yukgejang, Yongbongtang etc were combinated the taste of the several materials. 5. Cooking methods of Yukgaejang and Koritang before 19 century were different in present.: Yukgaejang was not used Gochoojang or powdered red pepper and Koritang was used Gochoojang.