• The Korean Journal of Ecology
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• v.23 no.2
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• pp.163-167
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• 2000

To evaluate the water purification capacity of 4 emergent macrophytes in 4 tributaries of Mankyung River, nitrate reductase activity (NRA) and nutrient removal capacity were determined. Higher NRA occurred in emergent macrophytes such as Persicaria thunbergii and Oenanthe iavanica with 7.8 and 5.4 ${\mu}$moi NO$_2$ g$^{-1}$d.wt. h$^{-1}$. respectively. The nitrogen removal capacity of emergent macrophytes displaying higher NRA fell within the range of 0.85 to 1.95 mg g$^{-1}$d.wt. day$^{-1}$ and was higher in the order Phragmites communis > Persicaria thunbergii > Oenanthe iavanica > Zizania latifolia. The phosphorus removal capacity was within the range of 0.07 to 0.12 mg g$^{-1}$d.wt. day$^{-1}$ and was higher in the order Phragmites communis > Oenanthe iavanica > Persicaria thunbergii > Zizania latifolia. In all the domestic, industrial and agricultural wastewaters, Phragmites communis showed the highest nitrogen and phosphorus removal capacity; 1.36 and 0.0088 mg g$^{-1}$d.wt. day$^{-1}$ respectively. Among the 4 macrophytes. Phragmites communis was the most suitable species for water purification in 4 tributaries of Mankyung River.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1757-1763
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• 2000

To consider the nutrient removal characteristics of BNR process activating soil microorganisms under the influence of DPB and to clear the characteristics of DPB under anoxic condition was investigated in the this study. The batch tests were conducted using sludge sampled from the BNR process activating soil microorganisms during operation periods. The results of this study were summarized as follows: - The DPB(Denitrifying Phosphorus removing Bacteria) performing denitrification and phosphorus uptake in the anoxic phase plays an important role in removing nitrogen and phosphorus in the BNR process activating soil microorganisms. - The PUR(Phosphorus Uptake Rate) of DPB in the anoxic phase was to be about 50% of PUR in the aerobic phase. - The DPB in the BNR process turned out to be increasing nutrient removal efficiency of BNR process.

• Journal of environmental and Sanitary engineering
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• v.20 no.2 s.56
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• pp.12-20
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• 2005

Most of sewage treatment plants in Korea is operated for the removal of organic material. Because of low C/N ratio of domestic wastewater it is very difficult to remove nitrogen and phosphorus from wastewater. Therefore C/N ratio is key factor for the removed of nitrogen and phosphorus. PSB(photosynthetic bacteria) can remove the nutrient materials, so this study is focused on PSB characterization of nutrient removal. PSB is possible to remove nitrogen, phosphorus in anaerobic and aerobic condition. This study try to find out condition of the PSB in SBR reactor, Batch reactor. It consists of three Mode. Mode 1, 2 is to apply activated sludge process and Mode 3 is that seeded PSB in the activated sludge process. As a result of SBR process, Mode 1, 2 which was activated sludge Process showed $79\~90\%,\;66\~90\%$ of SCODcr, $94.67\~95.89\%,\;95.76\~98.56\%$ of TKN, and Mode 3 has $84\~92\%$ of SCODcr, $95.39\~99.52\%$ of TKN removal efficiency, respectively. When comparison with Mode 1, 2 and 3, most of nitrogen and phosphorus is removed at the anaerobic condition in Mode 3. but Mode 1, 2 has just revealed activated sludge process characterization. It would because of characterization of PSB.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.102-109
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• 2012

In this study, the four different filter media (sponge, volcanic stone, activated carbon and magnesium hydroxide) were tested for the removal of algae and phosphorus in the two eutrophic water samples (natural water and artificial algal culture with BG-11 medium). These filter media were used in the column device as single or combined applications. The effect of the $Mg(OH)_2$ on phosphorus removal was examined using different particle sizes (<2 mm and >2 mm) and concentrations (0, 10, 50 and 100 g $L^{-1}$) of magnesium hydroxide. The removal efficiency of phosphate by magnesium hydroxide was increased with longer experimental time and higher concentration. However, there was no significant difference in the degree of phosphorus removal between any two particle sizes (1 mg P $L^{-1}$: F=0.109, P=0.685; 10 mg P $L^{-1}$: F=1.542, P=0.355). Among the four media, activated carbon showed the most potent effect on the removal of both algae and phosphorus. The highest removal efficiency of algae and phosphorus was obtained by combining four columns of each filter medium. Interestingly, integration of four filter columns showed higher removal efficiency than activated carbon alone. The highest removal efficiency by integrated filter columns seemed to be caused by a synergistic effect of combined activated carbon and magnesium hydroxide.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.4
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• pp.579-589
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• 2012

To reduce extensive energy costs of the internal recycling for the purpose of denitrification in the advanced wastewater treatment, a post-treatment process using an electro-coagulation to treat nitrate in the secondary effluents is evaluated in this study. Removals of phosphorus and organics in the secondary effluents by the electro-coagulation were also evaluated to propose an alternative advanced wastewatert treatment process. A series of experiments of the electro-coagulation were carried out with the following 4 different samples: synthetic solution containing nitrate only, synthetic solution containing nitrate as well as phosphorus, secondary effluents from activated sludge cultivated in laboratory, and secondary effluents from real wastewater treatment plants. Removals of nitrate and phosphorus in the synthetic solution were 30 and 97 % respectively, which verified the feasibility of the process. Removals of nitrate, phosphorus and COD in the secondary effluents from the cultivated sludge in laboratory were 49, 90 and 19 % respectively. Removal efficiency of the total nitrogen, nitrrate, phosphorus and COD in the secondary effluent from real wastewater treatment plant were 50, 61, 98 and 80 % respectively. The removal of the total nitrogen was less than the nitrate as expected, which is due to the formation of ammonia nitrogen in the cathode. But the proposed scheme could be an energy saving and alternative process for the advanced wastewater treatment if further studies for the process optimization are carried out.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.692-697
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• 2004

Biological phosphorus removal is characterized by complex interactions between different intracellular components of energy as PHA. Therefore, fundamental understanding of the behavior of the intracellular components and their influence on the removal of phosphorus is essential before control strategies to stabilize the proper process. The purpose of this study is to investigate relationship between release of phosphorus and synthesis of intracellular storage polymer. Mass of stored intracellular storage polymer was 21.2 mg PHA/L, 28.8 mg PHA/g MLSS. And phosphorus release/intracellular storage polymer synthesis rate was 1.8545 mg stored polymer/mg Phosphate. In the aerobic phase, mass of PAOs synthesis is 49.37 mg PAOs/L. And PAOs fraction was 6.7-6.9%. Thus intracellular storage polymer synthesis by PAOs is calculated as 493mg PHA/g PAOs.

• Environmental Engineering Research
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• v.17 no.4
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• pp.197-203
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• 2012

Phosphorus removal during discharge of wastewater is required to achieve in a very high level because eutrophication occurs even at a very low phosphorus concentration. However, there are limitations in the traditional technologies in the removal of phosphorus at very low concentration, such as at a level lower than 0.1 mg/L. Through a series of experiments, a possible technology which can remove phosphate to a very low level in the final effluent of wastewater was suggested. At first Al, Zn, Ca, Fe, and Mg were exposed to phosphate solution by impregnating them on the surface of activated alumina to select the material which has the highest affinity to phosphate. Kinetic tests and isotherm tests on phosphate solution have been performed on four media, which are Ca-impregnated activated alumina, activated alumina, Ca-impregnated loess ball, and loess ball. Results showed that Ca-impregnated activated alumina has the highest capacity to adsorb phosphate in water. Scanning electron microscope image analysis showed that activated alumina has high void volume, which provides a large surface area for phosphate to be adsorbed. Through a continuous column test of the Ca-impregnated activated alumina it was discovered that about 4,000 bed volumes of wastewater with about 0.2 mg/L of phosphate can be treated down to lower than 0.14 mg/L of concentration.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.629-635
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• 2012

This study was conducted to evaluate the removal behaviors of DOM(dissolved organic matter) and phosphorus in eutrophic lake water by coagulation process with PAC(powdered activated carbon). It was observed that the removal characteristic of soluble matter was different from that of dissolved one, and the removal of DOM was effected by both pH and coagulant dosage. It was founded that PAC could increase the removal efficiency by an adsorption of DOM in coagulation process. A formation of soluble and colloidal matters resulted in the degradation of phosphorus removal efficiency in a chemical precipitation process. The phosphorus removal efficiency could be enhanced by an absorption of colloidal matter and dissolved complex with PAC addition. In addition, the PAC addition caused the increase of floc density in coagulation process, that led to the rise of sedimentation rate, and resulted in a significant improvement of solid-liquid separation efficiency.

• Journal of Environmental Health Sciences
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• v.43 no.6
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• pp.525-531
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• 2017

Objectives: The purpose of this experiment is to better understand the nitrogen and phosphorus removal ratio according to operating conditions in an iron electrolysis system consisting of an anoxic basin, aerobic basin, and iron precipitation apparatus. Methods: Iron electrolysis consists of an iron precipitation reactor composed of iron plates in oxic and anoxic basins. We studied the interrelation coefficient between T-N and T-P removal rates and F/M ratio, and the C/N ratio and BOD removal rate. Results: The F/M ratio and the T-N and T-P removal rate per unit area have interrelation coefficients of 0.362 and 0.603, respectively. The removal rate per MLVSS and the T-N and T-P removal rate per unit area have respective interrelation coefficients of 0.49 and 0.59. Conclusions: The removal rate of T-N and T-P increased with the increasing F/M ratio in the influent, and they also linearly increased in proportion to the C/N ratio of influent and BOD removal rate of the reactor.

• Journal of Korean Society of Water and Wastewater
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• v.8 no.2
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• pp.25-34
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• 1994

In this research, investigations were made on the effect of type and load of organic substrate on phosphorus release. Reactors of three different sizes were operated, being fed on five kinds of organic substrates. The quantitative analyses were made on phosphorus release and substrate utilization under anaerobic condition. The molar ratios of the uptaken organic substrate to the released phosphorus were 0.5 with acetate, 0.6 with glucose, 0.8 with glucose/acetate, and 1.2 with glucose/acids, respectively. The phosphorus release was inhibited at the higher organic load than the normal at stead state. Both acetate and acids/glucose enhanced phosphorus release- as well as uptake-rate, however, the complete phosphorus removal was achieved after the microbial adaptation to the new environment. In case with acetate, operation was hampered by the poor sludge settleability and phosphorus uptake was not enough although the phosphorus release was active. But with milk/starch, the phosphorus release and uptake was well developed even though phosphorus release was not comparatively high. From this study, it was concluded that organic substrates, such as glucose seemed to be converted fatty acids after fast bio-sorption, followed by concurrent uptake of these acids by excess phosphorus removing bacteria.