• Proceedings of the Korea Water Resources Association Conference
• /
• 1992.07a
• /
• pp.77-85
• /
• 1992

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.1
• /
• pp.121-132
• /
• 2000

This study is to investigate the performance of a new BNR process using predenitrification scheme focusing on nitrogen removal and the possibility of adapting a computer simulation scheme in BNR process development. By using a pre-denitrification basin, higher $COD/NO_3-N$ ratio could be sustained in this BNR process. The results of the investigation showed a SDNR value of 9.04mg/gMv/hr. In the anoxic tank, the average value of SPRR of 6.25mgP/gMv/hr was observed to be very sensitive to SCOD load of influents. By calibrating internal parameters (stoichiometric and kinetic parameters) of the simulation model, the results of simulation for various BNR processes gave good agreement with observed data. The major adjustment was given with three parameters, maximum specific growth rate of heterotrophic biomass, short chain fatty acid (SCFA) limit, and phosphorous release rate. With the series of simulations on varying operational conditions, the simulation by computer program can be a useful tool for process selection, and design and operation of municipal wastewater treatment plant.

• Journal of Korean Society of Environmental Engineers
• /
• v.29 no.12
• /
• pp.1345-1352
• /
• 2007

To predict the effects of nutrient releasing on the water quality of Namyang Reservoir, nutrient releasing rates from sediments in oxic and anoxic conditions were estimated in a small microcosm. Organics and nitrogens were not released. The releasing pattern of inorganic phosphate and total phosphorus was depend on the oxygen concentration. The releasing rate of inorganic phosphate and total phosphorus in oxic condition was $1.01\sim2.48$ and $2.14\sim3.54$ mg-P/$m^2$/day, respectively. It was high in the upstream sediments indicating the particles containing easily degradable organic compounds are flowed into the area. Because the depth of Namyang Reservoir at the downstream adjacent to the Dam is $7\sim14$ m, the condition of most area of sediment surface will be oxic. Based on these results, the appropriate counterplans are required to reduce phosphorus release in oxic conditions to control water pollution.

• Journal of Navigation and Port Research
• /
• v.36 no.6
• /
• pp.513-519
• /
• 2012

Understanding the behavior of pollutants in the marine environment is essential for coping with the marine pollution problems such as eutrophication. In this study, the effects of environmental parameters on phosphorus release from marine sediment to sea water were investigated. The environmental parameters such as pH in the range of 7 to 9, temperature from 10 to 20C and dissolved oxygen levels (DO) renging 0.7 to 7.0mg/L were examined. Phosphorus release data were taken from batch tests excluding biotic effects, and analyzed using a first-order kinetic model. The effects of environmental parameters were quantified using a statistical methodology. High pH, high temperature, and low DO increased phosphorus release from the sediment to sea water. pH from 7 to 9, temperature from 10 to $20^{\circ}C$, or DO from 7.0 to 0.7 mg/L magnified the equilibrium phosphorus concentration up to 2~3 times.

• Journal of Korean Society of Environmental Engineers
• /
• v.39 no.9
• /
• pp.519-526
• /
• 2017

This study investigated the effect of phosphorus fractionation on the phosphorus release from the sediments of Juksan reservoir in Yeongsan River. The field sediments were collected, incubated, and analyzed with respect to phosphorus fractionation of sediments and total phosphorus (TP) of overlying water after 7 days. The total amount of inorganic phosphorus of YS2 site was higher than YS1 site. Al-P and Fe-P were major constituents of inorganic phosphorus. During the incubation, Al-P, Fe-P and Ca-P were increased and Red-P was decreased at both sites. YS1 site showed increased TP concentration of overlying water, however, YS2 had opposite trend during the incubation. Counting on the particle size distribution of YS1 and YS2, particle size distribution is major factor to control the TP concentration of overlying water. There were positive relationship between Fe-P and TP and negative relationship between Red-P. From the results, it is essential to continuously monitor the sediment phosphorus fraction in order to control the TP concentration of the water.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.11
• /
• pp.781-790
• /
• 2014

Contaminants such as organic matters, nutrients and toxic chemicals in rivers and lakes with a weak flow rate are first removed from the water and accumulated in the sediments. Subsequently, they are released into the water column again, posing direct/indirect adverse effects on the water quality and aquatic ecosystems. In particular, phosphorus is known to accelerate the eutrophication phenomenon when it is released into the water column via physical disturbance and biological/chemical actions as one of important materials that determine the primary production of aquatic ecosystems and an element that is stored mainly in the sediments in the process of material circulation in the body of water. In this study, the effect on reducing phosphorus release in sediments was analyzed by applying different capping materials to lake water, where the effect of aquatic microorganisms is taken into account, and to distilled water, where the effect of microorganisms is excluded. The experimental results showed that capping with chemical materials such as Fe-gypsum and $SiO_2$-gypsum further reduced the phosphorus release by at least 40% compared to the control case. Composite materials like granule gypsum+Sand showed over 50% phosphorus release reduction effect. Therefore, it is determined that capping with chemical materials such as granule-gypsum and eco-friendly materials such as sand is effective in reducing phosphorus release. The changes in phosphorus properties in the sediments before and after capping treatment showed that gypsum input helped to change the phosphorus that is present in lake sediments into apatite-P, a stable form that makes phosphorus release difficult. Based on the above results, it is expected that the application of capping technology will contribute to improving the efficiency of reducing phosphorus release that occurs in river and lake sediments.

• Journal of Korean Society of Environmental Engineers
• /
• v.30 no.5
• /
• pp.500-506
• /
• 2008

Enhanced phytoremediation with EDTA or PSM(Phosphate solubilizing microorganism) was studied using green foxtail (Setaria viridis) in columns packed with 1,200 mgPb/kg contaminated soil to investigate the effects of EDTA or PSM on the plant uptake and vertical migration of Pb. EDTA, equimolar amount of total Pb in the column soil, was administered in two methods: the one was treated with 1/6 aliquots of the equimolar EDTA every week for 6 weeks and the other was treated with single dose of the equimolar EDTA before 14 days of harvest. The results showed that higher concentrations of Pb accumulated in the biomass of green fowtail after the chemical or biological treatment. The plant-root Pb concentration in PSM treatment(M), EDTA aliquot treatment(ES), and single dose treatment(E) was 2.6, 3.0, and 3.3 times higher, respectively, than that in the plant-root of control(164.7 mg/kg). The plant-stem Pb concentration in the M, ES and E treatment was 27, 37, and 40 times higher than that in the stem of control(8.1 mg/kg). The translocation factor, the ratio of shoot/root Pb concentration, was 0.6 in the two EDTA treatment, 0.5 in the M treatment, and 0.05 in the control, respectively. The largest amount of Pb was phyto-extracted in the E treatment whereas vertical migration of EDTA was significant in the ES treatment. This result showed that a single large dose of EDTA before harvest serves better for enhanced phytoremediation of Pb. Although, treatment with PSM showed less Pb phytoextraction by the plant but enhanced both the growth of plants in the column and microbial dehydrogenase activity in the soils. Therefore, enhanced phytoextraction of Pb with PSM treatment can be an alternative option for EDTA treatment, which is toxic to plants and soil ecosystem.

• Korean Journal of Ecology and Environment
• /
• v.38 no.3 s.113
• /
• pp.372-381
• /
• 2005

This study was conducted to test the efficiency of water quality improvement using the dissolved air flotation (DAF) technique in a shallow eutrophic reservoir. The application of DAF was followed by the addition of a chemical coagulant (poly aluminum chloride; PAC). The experiment was conducted in the mesocosm scale (wide ${\times}$ length ${\times}$ depth: 6 m ${\times}$ 6 m ${\times}$ 3 m). Suspended solids (SS) and volatile SS (VSS) concentration decreased by 54 ${\sim}$ 71% and 57 ${\sim}$ 79% of the initial concentrations, respectively. Total phosphorus and Chl- a concentration also decreased by 74 ${\sim}$ 92% and 54 ${\sim}$ 98%, respectively. BOD decreased by>86% while COD decrease ranged 29 ${\sim}$ 63%. Dissolved inorganic P (DIP) and dissolved total P (DTP) concentration decreased by 34 ${\sim}$ 88% and 62 ${\sim}$ 88%, respectively. After DAF application further onto the sediment, DIP-release rates from the sediment decreased by 17% (0.82 ${\to}$ 0.68 mg $m^{-2}$$day^{-1}$ in the oxic condition and 23% (2.27 ${\to}$ 1.76 mg $m^{-2}$$day^{-1}$) in the anoxic condition, compared to the release rate from the untreated sediment. DTP-release rate from both the oxic and anoxic sediments also decreased by 33% (5.62 ${\to}$ 3.78 mg $m^{-2}$$day^{-1}$) and 20% (6.23 ${\to}$ 4.99 mg $m^{-2}$$day^{-1}$), respectively. These results suggest that the DAF application both to the water column and onto the sediment be effective to improve water quality by removing particulate matters in the water column as well as reducing P-release from the sediment.

• Journal of Korean Medical classics
• /
• v.18 no.1 s.28
• /
• pp.67-72
• /
• 2005

통과분석(通過分析)${\ulcorner}$동의보감(東醫寶鑑)${\lrcorner}$양명형증용약여포괄중경적(陽明形證用藥？包括仲景的)${\ulcorner}$상한론(傷寒論)${\lrcorner}$재내적주요의학가대양명병적개념(在內的主要醫學家對陽明病的槪念), 득출여하결론(得出如下結論): 1.${\ulcorner}$동의보감(東醫寶鑑)${\lrcorner}$적양명형증용약당중이대편비결위중심, 미사용가이낭괄양명병증재내적위가실저개개념, 상세나열출양명병적구체증상 내급양명병하료정의(來給陽明病下了定義). 병미장대편비결작위대표성증상(幷未將大便秘結作爲代表性症狀), 이시근거표본관계분성경병여부병진행설명. 이기육작위표(以肌肉作爲表), 위작위리적표리개염분석기증상(胃作爲裏的表裏槪念分析其症狀). 2. 기찰급양명병하정의적의서(畿察給陽明病下定義的醫書), 발현제료중경적(發現除了仲景的)${\ulcorner}$상한론(傷寒論)${\lrcorner}$여기주석본성무이적${\ulcorner}$주해상한론(注解傷寒論)${\lrcorner}$이외(以外), 도장목동(都將目疼), 비건(鼻乾), 불득면부간주양명병대표증상(不得眠部看做陽明病代表症狀). 저충정의방식시종송도명대적보편관점 3. 재(在)${\ulcorner}$동의보감(東醫寶鑑)${\lrcorner}$당중작위인용서목적${\lrcorner}$의학입문(醫學入門)${\ulcorner}$, 근거표본(根据標本), 표리개염대증상진행료분류(表裏槪念對症狀進行了分類). 비기지전단순적대증상적서술갱구유조리성. 저가이간주시집당시제다견해지대성(這可以看做是集當時諸多見解之大成), 대병정적분석변적갱가구체. 선택(選擇)${\lrcorner}$의학입문(醫學入門)${\ulcorner}$작위인체서목(作爲引滯書目), 가이인위시채납료당시적최신견해, 병차흡수료용역장악병정적이증상위주적기술방식(幷且吸收了容易掌握病情的以症狀爲主的記述方式). ${\lrcorner}$의학입문(醫學入門)${\ulcorner}$취시집이상관점위일체적대성(就是集以上觀点爲一體的大成). 4. 여태양병당중양형증용약진행비교, 관찰병정적주요관점(觀察病情的主要觀点), 양자도추종료(兩者都追從了)${\lrcorner}$의학입문(醫學入門)${\ulcorner}$적견해(的見解). 단시태양형증용약몰유대몰위초출중경태양병적제망(但是太陽形證用藥沒有大沒圍超出仲景太陽病的提網), 상비지하양명형증용약기몰유인용(相比之下陽明形證用藥旣沒有引用) 중경적(仲景的)${\ulcorner}$상한론(傷寒論)${\lrcorner}$, 대증상적설명야대상경정(對症狀的設明也大相徑庭). 5. 양명형증용약당중몰유인용중경적위가실관점, 이시리용미악한(而是利用微惡寒), 발열(發熱), 갈(渴), 유한(有汗), 목동(目疼), 비건(鼻乾), 조한(潮汗), 폐삽(閉澁), 만갈(滿渴), 광섬, 불면등증상진행설명(不眠等症狀進行說明), 비기장악륭명병작위장부질병(比其掌握隆明病作爲臟腑疾病), 이해위이열위주적상당우양명속성적질병.