• Korean Journal of Microbiology
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• v.37 no.4
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• pp.317-324
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• 2001

We have previously developed three stage methane fermentation system capable of digesting food wastes effectively and then releasing high organic wastewater as a final product. In this study, we tried to devise an ecological water treatment system, which can efficiently remove the nitrogen and phosphorus contained in the organic wastewater. The system was made of microbiological filters, algae, and waterfleas. Of two species of alga tested, Selenastrum capricornutum showed higher growth rate and more efficiently removed the nitrogen from the wastewater than by Chlorella sp. In addition, the highest growth rate and the nitrogen removal efficiency could be obtained when high concentrations of $Mg^{2+}\; and\; Ca^{2+}$ were added to the diluted wastewater and the molar ratio of nitrogen to phosphorus was adjusted to 10 : 1. In this study the population relationship between alga and water flea was also examined in a test tube. The initial number of algal cells decreased as the waterflea population increased. However, the number of algal cells gradually increased again when waterflea population decreased partly due to the environmental resistance. From these results, it was believed that the ecological water treatment system could be used for removing the nitrogen and phosphorus from organic wastewater very effectively. Moreover, the waterflea cultured by this system as a final predator could be used as a good foodstuff for fishes.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.68-71
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• 2002

SPAD(Sulfur Particle Autotrophic Denitrification) process is a biological denitrification process which uses elemental sulfur as an electron donor and a mall amount of organic to assist autotrophic denitrification. $^{1)}$SPAD process was applied to a nitrate containing wastewater (200-300mg $NO_3\;^-$ -N/L) with high concentration of $Ca^{2+}$ ion(5000-15000mg/L) from S. Steel Co. in Ulsan city, to est the feasibility of SPAD process. This pilot was operated from November 2001 to early March 2002, and the inner temperature of the pilot was controlled around $20^{\circ}C$. In spite of low temperature, denitrification efficiency was maintained above 90% achieving the average effluent $NO_3\;^-N$ concentration around 20mg$NO_3\;^-$ -N/L.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1893-1904
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• 2000

Nitrogen compounds are one of the major pollutants which cause eutrophication problems of the river or lake and red tides problems of the ocean. Currently available technologies for the removal of nitrogen compounds are mostly biological treatment. However, biological treatment is only effective for the wastewater which contains low concentration of nitrogen compounds. Leachate from solid waste landfill or industrial wastewater which contains high concentration of nitrogen can not be effectively treated by most of the currently available biological treatment technologies. With this connection. the objective of this study is to examine the applicability of ammonia stripping technology for the removal of high concentration of ammonia nitrogen compounds of the leachate from solid waste landfill. It can be concluded that ammonia stripping technology which was placed before the biological treatment process was very effective for the removal of high concentration of ammonium compounds. The chemical cost for the ammonia stripping was 16 percent higher than MLE process, so other methods like sludge recycling are needed for the reduction of operation cost. Further details are discussed in this paper.

• Clean Technology
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• v.17 no.4
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• pp.363-369
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• 2011

To evaluate the feasibility of electrodialysis for ammonia nitrogen removal from wastewater, the effects of operating parameters such as diluate concentration, applied voltage and flow rate on the removal of ammonia nitrogen were experimentally estimated. The removal rate was evaluated by measuring the elapsed time for ammonia nitrogen concentration of diluate to reach 20 mg/L. Limiting current density (LCD) linearly increased with ammonia nitrogen concentration and flow rate. The elapsed time was linearly proportional to initial concentration of diluate. Due to relatively large equivalent ion conductivity and ion mobility of ammonia nitrogen, the removal rate increased consistently with flow rate. Increase in the applied voltage gave positive effect to removal rate. From the operation of the electrodialysis module used in this research, the flow rate of 3.2 L/min and 80~90% of applied voltage for LCD are recommended as the optimum operating condition for the removal from high concentrate ammonia nitrogen solution.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.8
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• pp.852-859
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• 2006

The novel microbial process such as Anammox(anaerobic ammonium oxidation) and Canon(completely autotrophic nitrogen removal over nitrite) processes is promising biotechnology to remove nitrogen from ammonium-rich wastewater like anaerobic sludge digester liquid. In this research, a new Canon-type nitrogen removal process adopting upflow granular sludge bed type configuration was investigated on its feasibility and process performance, using synthetic wastewater and sludge digester liquids. Air as an oxygen source was provided in an external aeration chamber with flow recirculation. In the first experiment using the synthetic wastewater(up to 110 mg $NH_4$-N $L^{-1}$), the ammonium removal was about 95%(92% for T-N) at effective hydraulic retention time(HRT) for 3.8 days. In the second experiment using the sludge digester liquids($438{\pm}26$ mg $NH_4$-N $L^{-1}$), the total nitrogen removal was $94{\pm}1.7%$ at HRT for 5.4 days and $76{\pm}1.5%$ at HRT for 3.8 days, respectively. Little nitrite and nitrate were observed in the effluent of both experiments. The process revealed quite a lower oxygen($0.29{\sim}0.59$ g $O_2$ $g^{-1}N$) and less alkalinity($3.1{\sim}3.4$ g $CaCO_3$ $g^{-1}N$) consumption as compared to other new technology in microbial nitrogen removal. The process also offers the economical compact reactor configuration with excellent biomass retention, resulting in lower cost for investment and maintenance.

• Resources Recycling
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• v.16 no.6
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• pp.52-60
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• 2007

Denitrification from aqueous solution was investigated through patent analysis and electrochemical denitrification experiment. Among several candidates, biological treatment and oxidation/reduction method are mainly discussed. Recently, patent pending concerning to electrochemical treatment is increasing. Based on basic electrochemical study, total nitrogen was removed up 47% by 1-hour galvanostatic electrolysis with Fe cathode and Pt anode. More applicable technique to industry could be mentioned combination of two or more technologies suitable to waste water characteristics. In the case of small and concentrate effluent, combination of chemical and electrochemical treatment would be recommendable because nitrate could be easily converted to nitrite by chemical treatment, and in that case denitrification by electrolysis becomes more efficient and metal ions from chemical treatment can be recovered during electrolysis.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.194-200
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• 2000

The amount of swine wastewater reaches about $197,000m^3$ per day at live-stock houses in the whole country. A half of the swine wastewater resources are too small to be restricted legally. This untreated wastewater causes the eutrophication in the water bodies. In case of swine wastewater treatment, the solid-liquid separation must be performed because feces(solid phase) and urine(liquid phase) have large differences in nitrogen and phosphorus concentration. It is necessary to assess exactly the concentration of the pollutants in swine wastewater for planning the wastewater treatment facilities. A full-scale operation was carried out in K city and the plant is consists of conventional plant, the supplementary flocculation basin of chemical treatment process and $anaerobic{\cdot}aerobic$ basin for nitrogen removal. The improved full-scale swine wastewater treatment plant removed the $1,500{\sim}3,000mg/l$ of total-nitrogen(T-N) to 120mg/l of T-N and $131{\sim}156mg/l$ of total-phosphorus(T-P) to $0.15{\sim}1.00mg/l$ of T-N. Accordingly, as a results of operational improvement, the removal efficiencies of T-N and T-P were over $92{\sim}96%$, 99%, respectively. The continuous supply of organic carbon sources and the state of pH played important roles for the harmonious metabolism in anaerobic basin and the pH value of anaerobic basin maintained at about 9.0 for the period of the study.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.4
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• pp.414-420
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• 2006

Effluent from an anaerobic digestion system with an elutriated phased treatment(ADEPT, Anaeorbic Digestion Elutriated Phase Treatment) for piggery waste treatment using anaerobic ammonium oxidation(ANAMMOX) process was used as a substrate of partial nitrification reactor. In mesophilic condition($35^{\circ}C$), controlling parameters of nitrite accumulation were HRT, pH, free ammonia(FA) and hydroxylamine rather than dissolved oxygen. Bicarbonate alkalinity consumption ratio including bicarbonate stripping and buffering was 8.78 g $Alk._{comsumed}/g\;NH_4-N_{converted}$. In steady state for 1 day of HRT and $2.7{\sim}4.4mg/L$ of DO, $NO_2-N/NH_4-N$ ratio of partial nitrification effluent was about $1{\sim}3$, which was applicable to ANAMMOX reactor influent for the combined partial nitrification-ANAMMOX process.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.409-414
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• 2006

Sulfur-oxidizing bacteria were enumerated and isolated from a steady-state anaerobic master culture reactor (MCR) operated for over six months under a semi-continuous mode and nitrate-limiting conditions using thiosulfate as an electron donor. Most are Gram-negative bacteria, which have sizes up to 12 m. Strains AD1 and AD2 were isolated from the plate count agar (PCA), and strains BD1 and BD2 from the solid thiosulfate/nitrate medium. Based on the morphological, physiological, FAME and 16S rDNA sequence analyses, the two dominant strains, AD1 and AD2, were identified as Paracoccus denitrificans and Paracoccus versutus (formerly Thiobacillus versutus), respectively. From the physiological results, glucose was assimilated by both strains AD1 and AD2. Heterotrophic growth of strains AD1 and AD2 could be a more efficient way of obtaining a greater amount of biomass for use as an inoculum. Even though facultative autotrophic bacteria grow under heterotrophic conditions, autotrophic denitrification would not be reduced.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.3
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• pp.140-147
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• 2011

We studied the influence of livestock waste leachate on oxidative damage and antioxidative responses in poplar clones in August which increase the demand of antioxidants because of high temperature and high light during this period. We measured ion leakage, antioxidant enzyme activities (APX, GR), and carotenoid contents. Oxidative damage and antioxidative responses by treated livestock waste leachate in poplar clones showed various results. We divided poplar clones into three groups using the criteria based on ion leakage which represent cell damage induced oxidative stress. Eco 28, 62-10, Bonghwa1 and Dorskamp belonged to the first group in which the cell damaged level was lower than that of the control. The results suggest that this group augmented for demand of antioxidative in summer because high concentration of nitrogen induced by treatment of live stock wastes acted as environmental stress. Consequently, they failed to keep up the homeostasis of reactive oxygen species. The second group in which the cell damaged level was similar to that of the control was Suwon, 72-30 and 72-31 clones. Finally, 97-18 clone belonged to the third group in which the cell damaged level was lower than that of the control group. In this case, nitrogen treated by livestock waste leakage decreased oxidative stress. 97-18 clone was the clones with the least damage in summer oxidative stresses treated by livestock waste leakage. These results suggest that the high concentration nitrogen due to the livestock waste leakage can act differently upon the clones. We speculate that the added oxidation damage in the summer (growing season) may have an effect on the total fresh weight and also influence the purification ability for livestock waste leakage. However, further studies are needed for the confirmation.