• 제목/요약/키워드: 질산성 질소

검색결과 583건 처리시간 0.026초

Modeling of the Nitrate Adsorption Kinetics onto $ZnCl_2$ Treated Granular Activated Carbon (염화아연으로 표면개질된 입상활성탄의 질산성질소 흡착속도의 모델링 연구)

  • Ji, Min-Kyu;Jung, Woo-Sik;Bhatnagar, Amit;Jeon, Byong-Hun
    • Journal of Soil and Groundwater Environment
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    • 제13권3호
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    • pp.21-26
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    • 2008
  • Nitrate adsorption from aqueous solutions onto zinc chloride ($ZnCl_2$) treated coconut Granular Activated Carbon (GAC) was studied in a batch mode at two different initial nitrate concentrations (25 and 50 mg/L). The rate of nitrate uptake on prepared media was fast in the beginning, and 50% of adsorption was occurred within 10 min. The adsorption equilibrium was achieved within one hour. The mechanism of adsorption of nitrate on $ZnCl_2$ treated coconut GAC was investigated using four simplified kinetic models : the rate parameters were calculated for each model. The kinetic analysis indicated that pseudo-second-order kinetic with pore-diffusion-controlled was the best correlation of the experimental kinetic data in the present adsorption study.

Nitrate Contamination of Confined Groundwaters: Application of Nitrogen, Oxygen, and Hydrogen Isotopes (피압대수층 지하수내 질소함유 원인연구: 질소, 산소, 수소동위원소 적용)

  • 추창오;이병대;조병욱;성익환;지세정
    • The Journal of Engineering Geology
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    • 제12권3호
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    • pp.285-294
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    • 2002
  • The origin of nitrate in confined groundwater was studied using oxygen ($\delta$180), hydrogen ($\delta$D), and nitrogen ($\delta$15N) stable isotopes, along with chemical data of NO3-N. We analyzed groundwaters from more than sixty manufactories producing natural mineral waters around the country During the period of 1998-2001, an average value of nitrate was fair]y low (0.95 mg/$\ell$), however, groundwaters from six sites showed more than 2 mg/$\ell$ of nitrate. The stable isotope data of the groundwaters are -8.3~-11 $\textperthousand$ $\delta$8O, -60~-75 $\textperthousand$ $\delta$D, which lies in an average range of the groundwaters. The nitrogen isotope data with -11.8~-5.1$\textperthousand$ $\delta$15N suggest that manure, organic nitrate, and fertilizers can not be the origin of nitrate in the goundwaters.

A Semi-Pilot Test of Bio-barrier for the Removal of Nitrate in Bank Filtrate (강변여과수의 질산성질소 제거를 위한 생물학적 반응벽체의 준파일럿 실험에 관한 연구)

  • Moon, Hee-Sun;Chang, Sun-Woo;Nam, Kyoung-Phile;Kim, Jae-Young
    • Journal of Korean Society of Environmental Engineers
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    • 제27권3호
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    • pp.302-308
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    • 2005
  • Nitrate is one of common contaminants frequently found in the bank filtrate. Biological autotrophic denitrification into permeable reactive barrier(PRB) system to reduce nitrate concentration in bank filtrate was implanted. The objectives of research are to investigate effect of inoculation, to evaluate alternative alkalinity sources, and to determine effect of hydraulic characteristics, such as retention time, flow rate on the performance of semi-pilot PRB system. Semi-pilot scale biological PRB system was installed using elemental sulfur and limestone/oyster shell as reactive materials near Nakdong River in Kyoungnam province, Korea. Nitrate concentration in bank filtrate was reduced by indigenous microorganisms in oyster shell as welt as by inoculating microorganisms isolated from the sludge of an anaerobic digester in a wastewater treatment plant. Oyster shell as well as limestone can be used as an alkalinity source. However, oyster shell resulted in suspended solids of effluent. As the flow rate in the system increased from 66 to 132 mL/min and accordingly the residence time decreased from 15 to 7.5 hours, nitrate concentration in effluent increased and nitrate removal efficiencies decreased from 75 to 58% at the fixed thickness of 80 cm of PRB.

Particle Size Effects of Devarda's Alloy on the Recovery of Nirate N Determined by the Steam Distillation Method (질산태 질소 정량을 위한 환원 증류법에서 Devarda's Alloy의 입자크기 및 함량이 미치는 영향)

  • Jung, Seok-Ho;Kwon, Hyun-Jae;Chung, Doug-Young;Han, Gwang-Hyun
    • Korean Journal of Soil Science and Fertilizer
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    • 제44권3호
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    • pp.387-393
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    • 2011
  • We analyzed the particle size distributions of three commercially available Devarda's alloy (DA) products, tested the nitrate recoveries of each particle size category, and examined the amounts of DA required for 100% recovery by varying $NO_3$-N concentration from 0.5 to 10 mg. We observed that use of DA coarser than 200 mesh resulted in poor analytical recovery (<80%). While the tested alloys were considered to be fine enough (>90% of the particles were less than 100 mesh), the recovery dramatically declined from 80% to 10% in a high concentration range (4 to 10 mg N). Satisfactory recovery was obtained by increasing the amount of finer DA (less than 300 or 450 mesh). However, there was no quantitative relationship between the amount of fine DA and nitrate recovered. Generally, the amount of nitrate reduced per unit DA decreased as the recovery efficiency declined. These results suggest that a sufficient amount of DA must be determined based on particle size distribution, and that treatment of at least two levels of DA and comparison of the subsequent change in nitrate recovery is required for soils containing high levels of nitrate. In addition, further studies are encouraged to account for the observed stoichiometric dis-equivalence of recovered nitrate N per unit mass of DA.

Continuous Nitrate Removal using Bipolar ZVI Packed Bed Electrolytic Cell (영가철(Fe0) 충진 복극전해조를 이용한 질산성질소의 연속식 제거 연구)

  • Jeong, Joo-Young;Kim, Han-Ki;Shin, Ja-Won;Park, Joo-Yang
    • KSCE Journal of Civil and Environmental Engineering Research
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    • 제32권1B호
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    • pp.79-84
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    • 2012
  • Nitrate is a common contaminant in groundwater aquifer. The present study investigates the performance of the bipolar zero valent iron (ZVI, $Fe^0$) packed bed electrolytic cell in removing nitrate in different operating conditions. The packing mixture consists of ZVI as electronically conducting material and silica sand as non-conducting material between main cathode and anode electrodes. In the continuous experiments for the simulated wastewater (contaminated groundwater, initial nitrate about 30 mg/L as N and electrical conductivity about 300 ${\mu}S/cm$), over 99% removal of nitrate was achieved in the applied voltage 600 V and at the flow rate of 20 mL/min. The optimum packing ratio (v/v) and flow rate were determined to be 1:1~2:1 (silica sand to ZVI), 30 mL/ min respectively. Effluent pH was proportional to nitrate influx concentration, and ammonia which is the final product of nitrate reduction was about 60% of nitrate influx. Magnetite was observed on the surface of the used ZVI as major oxidation product.

Catalytic Nitrate Reduction in Water over Nanosized TiO2 Supported Pd-Cu Catalysts (나노 크기의 타이타니아 담체를 활용한 Pd-Cu 촉매의 수중 질산성 질소 저감 반응에의 적용)

  • Kim, Min-Sung;Lee, Jiyeon;Lee, Kwan-Young
    • Clean Technology
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    • 제20권1호
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    • pp.28-34
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    • 2014
  • In this study, we synthesized $TiO_2$ supports with nanosized crystalline structure by solvothermal method and prepared $TiO_2$ supported Pd-Cu catalysts. It was shown that the crystalline size of $TiO_2$ support in the catalyst influenced on the catalytic activity of nitrate reduction in water. The catalyst with the smaller crystalline size of $TiO_2$ support presented faster nitrate reduction rate, but had low nitrogen selectivity due to high pH environment of reaction medium during the reaction. Through injection of carbon dioxide as a pH buffer, the nitrogen selectivity increased by about 60%. Furthermore, we investigated that the relationships between the catalytic performance and the physicochemical properties of the prepared catalysts characterized by $N_2$ adsoprtion-desorption, X-ray diffraction (XRD), $H_2$-temperature programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS).

Analysis of Influential Factors on Nitrate Distribution in Ground Water in an Urbanizing Area using GIS (도시화 지역에서 GIS를 이용한 지하수 질산성질소 분포 영향요인 분석)

  • Won J.S.;Woo N.C.;Kim Y.J.
    • Economic and Environmental Geology
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    • 제37권6호
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    • pp.647-655
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    • 2004
  • To identify the influential factors and their relative significance on spatial distribution of $NO_3-N$ in urban ground water, spatial analysis was conducted using GIS and statistical approaches in the Seongnae-Koduk watersheds, where rapid urbanization has been proceeded. Several factors were considered including land-use type, distance to sewage lines, the ratio of impervious surface, and the ratio of green area. The spatial distribution of $NO_3-N$ in the land-use types shows differences between urban and crop field possibly due to the sewage networks in urban areas and the agrochemical uses in crop field. Nitrate concentrations in ground water were decreased with the distance to sewage lines to approximately 60-75 m. Concentrations of nitrate and distances to sewage lines showed negative correlation, indicating that the nitrate contamination was induced from the sewage system and specially significant in urban areas. The negative correlation of the ratio of impervious surface to the nitrate concentration in urban areas also suggested that the source materials of nitrate are introduced from the surface. Consequently, in areas of urbanization processes, systematic management of past-and-present land-use types and sewage systems are the most significant factors in preventing ground water from nitrate contamination.

Effects of Operating Parameters on the Removal Performance of Nitrate-nitrogen by Electrodialysis (전기투석을 이용한 질산성 질소의 제거 시 운전인자의 영향)

  • Lee, Gwan-Ho;Lee, Gang-Choon
    • Clean Technology
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    • 제15권4호
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    • pp.280-286
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    • 2009
  • To evaluate the feasibility of electrodialysis for nitrate-nitrogen removal from wastewater, the effect of operating parameters on the removal of nitrate-nitrogen was experimentally estimated. The limiting current density (LCD) linearly increased with the nitrate concentration and the flow rate. The time when the nitrate concentration of diluate reached at 20 mg/L was linearly proportional to concentration of diluate, and the concentration of concentrate did not affect the removal rate. Increase in the flow rate gave a positive effect on the removal rate and became insignificant at How rates greater than 1.6 L/min. The removal rate increased with the applied voltage, but the increment in the removal rate decreased as the applied voltage approached the LCD. From the operation of the electrodialysis module used in this research, the flow rate of 1.6 L/min and the voltage corresponding to the 80~90% of LCD were found be the optimum operating condition for the nitrate removal from highly concentrated nitrate-nitrogen solutions.

Hydrogeochemical Environmental Research in Nitrate Contamination in Alluvial Fan Area Groundwater in Tsukui, Central Japan (일본 츠꾸이 선상지 지하수의 질산성 질소 오염에 대한 수문지구화학적 연구)

  • Okazaki, Masanori;Ham, Young-Sik
    • Korean Journal of Ecology and Environment
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    • 제37권4호통권109호
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    • pp.431-435
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    • 2004
  • A nitrate-contaminated groundwater was hydrogeochemically investigated to estimate the factors controlling groundwater quality in an alluvial fan area. Even though monthly groundwater levels increased with monthly rainfalls, the monthly $NO_3^--N$ concentrations in groundwater showed a small variation, mostly exceeding a maximum contaminant level of 10 mg $L^{-1}$ in environmental quality standards for groundwater during 2003. The 2003 annual groundwater recharge was 1,730 mm =20,056 mm-18,326 mm. Where 20,056 mm and 18,326 mm are annual sum of daily increase and decrease in ground water level. However, the annual sum of increase in ground water level (20,056 mm) was approximately 10 times higher than annual rainfall. Moreover, the annual sum of daily ground water level decrease (-18,326mm) showed that a large amount of groundwater was discharged with $NO_3^-$-contamination. Hydrogeochemically, a large amount of groundwater input and output through the alluvial fan area were observed after rainfall with a considerably high concentration of $NO_3^-$. Consequently, this alluvial fan area including forest area reflects on the evidence under the condition of 'nitrogen excess' or 'nitrogen saturation'. In addition, such a large amount of groundwater outflow can cause environmental damage in surface water, associated with $NO_3^-$- contamination. This study also expects that this hydrogeochemical data will be useful for water management.

Effect of Influent C/N Ratio and DO on Denitrification of Nitrate Polluted Groundwater in a Biofilter Process (Biofilter 공정에서 유입 C/N비와 DO가 지하수의 질산성 질소제거에 미치는 영향)

  • Lee, Moo-Jae;Park, Sang-Min;Park, Noh-Back;Jun, Hang-Bae;Kim, Kong-Soo
    • Journal of Korean Society of Environmental Engineers
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    • 제28권4호
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    • pp.355-361
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    • 2006
  • In this study, effects of influent C/N(COD/Nitrate) ratio and dissolved oxygen(DO) concentration on biological nitrate removal from groundwater were investigated in the fixed-type biofilter. Influent nitrate of 30 mg/L was removed completely by biological denitrification at the C/N ratio of 10 and 4.0, while residual nitrate of 5 mg/L occurred at the C/N ratio of 2.0, which resulted from deficiency of organic electron donor. Furthermore, nitrite was accumulated up to about 5 mg/L as the C/N ratio decreased to 2.0. Increase in DO concentration also inhibited denitrification activity at the relatively high C/N ratio of 5.0, which decreased the nitrate removal efficiency. Although the influent DO concentration was reduced as low as 0.3 mg/L using sodium sulfite($Na_2SO_3$), effluent nitrite was up to 3.6 mg/L. On the other hand, nitrate was completely removed without detection of nitrite at the DO concentration of 0.3 mg/L using nitrogen gas($N_2$) sparging. The organic matter for denitrification in biofilter were in the range from 3.0 to $3.5gSCOD/g{NO_3}^--N$, while utilized these values increased at the high DO concentration of 5.5 mg/L. In addition to the high DO concentration and the low influent C/N ratio, DO control by chemical such as sodium sulfite affected on biological denitrification, which resulted in the reduction of nitrate removal efficiency and nitrite build-up in a biofilter.