• Korean Journal of Ecology and Environment
• /
• v.36 no.3 s.104
• /
• pp.269-276
• /
• 2003

The study was performed to understand the relationships of cyanobacterial bloom and environmental factors in Lake Daechung. The samples were collected weekly from June to October in 2001. The cyanobacterial bloom was divided into the three phases of the early phase, the middle phase and the late phase by phytoplankton standing crops. For the early phase, the correlation coefficients between chl- a and TP, and chl- a and $PO_4$-P were 0.986 and 0.894 respectively. Therefore, phosphorus was a main environmental factor in the development of cyanobacterial bloom. Zeu/Zm ratio and chl-a showed negative correlation of r = -0.995. At the late phase, $PO_4$-P showed the highest relationship (r = 0.958), and TP and temperature showed relatively high relationships (r = 0.857 and r = 0.813). At the late phase, $NH_3$-N showed highly positive relationship (r = 0.921). It was confirmed that $PO_4$-P was the most important contribution factor for the bloom through the regression analysis on the environmental factors. As the result, the decrease of Zeu/Zm ratio and the increase of P concentration influenced cyanobacterial bloom developed rapidly in the early phase. Also the cyanobacterial bloom was decreased in proportion to decreasing of $NH_3$-N concentration in the late phase. It was expected that observation of $NH_3$-N may be a very useful factor on monitoring of the decreasing situation of the bloom.

• Journal of Power System Engineering
• /
• v.14 no.6
• /
• pp.13-19
• /
• 2010

이 논문에서는 디젤자동차용 LNT와 SCR 촉매의 NO, $NH_3$ 흡착 및 탈리의 기본 특성과 수열화 온도와 시간 및 정량화된 황피독 농도에 대한 de-$NO_x$ 촉매의 내구성을 평가하였다. LNT 촉매는 열적으로 열화됨에 따라 Pt 및 Ba의 소결 및 응집으로 활성이 떨어져 $NO_x$ 전환율은 감소하였다. 반면에 Pt의 비활성화로 중간생성물인 $NH_3$ 생성량은 증가하였으며, 이때 생성된 $NH_3$는 LNT+SCR 복합시스템의 SCR 촉매의 환원제 역할을 담당한다. 1.0 g/L 이상의 황이 피독된 LNT 촉매는 탈황을 하여도 질소 산화물 흡장물질(Ba) 의 성능이 회복이 되지 않아 $NO_x$ 전환율은 회복되지 않았으며, 탈황 후 Pt 재활성화로 인해 NO2 및 SCR 환원제인 $NH_3$ 생성량은 증가하였다. SCR 촉매의 $NO_x$ 전환율은 $700^{\circ}C$ 36h, $800^{\circ}C$ 24h로 수열화 시킨 촉매는 전이금속 입자 성장 및 zeolite 구조 파괴로 인하여 급격하게 떨어졌으며, 0.36 g/L 황 피독된 촉매는 zeolite가 가지는 강산성 특정으로 내피독성이 강하여 탈황시 $NO_x$ 전환율은 회복되었다.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.25 no.3
• /
• pp.5-13
• /
• 2023

This study aims to assess the water quality of the Eoran and the Imha aquafarm with different aquafarm environments in Haenamn-gun, and analyzed the composition of total amino acids (TAAs) and free amino acids (FAAs) in three Neopyropia dentata cultivars (Yuldo, Supum1 and 2) in two aquafarms. Mean water temperature ranged from 22.9 to 10.9℃ during September to November 2018. In Eoran aquafarm, the water quality analysis showed that NO₂-N was high in September, NH₄-N and COD in October, and NO₃-N, DIN, and DIP in November. In Imha aquafarm, the water quality analysis showed that NH₄-N and COD was high in September, NO₃-N and DIN in October, and NO₂-N and DIP in November. We confirmed the proximate composition, amino acid composition (TAA/FAA) in two auqufarms. In the Eoran aquafarm, the 'Yuldo' cultivar had significantly higher crude lipid content than two other cultivars (Supum 1 and 2). The 'Supum1' cultivar had significantly higher moisture content, whereas the highest content of crude protein, crude lipid, crude ash, and carbohydrates was found in the 'Supum2' cultivar. In the Imha aquafarm, the content of crude lipid and crude ash was highest in the 'Yuldo' cultivar. The highest content of crude protein and carbohydrates was found in the 'Supum1' cultivar, while the 'Supum2' cultivar had the highest content of moisture. The highest concentration of glutamic acid belong to TAAs is observed in all cultivars from Eoran and Imha aquafarm, while all cultivars in two aquafarm also contained higher content of alanine among the detected FAAs.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.7
• /
• pp.3267-3274
• /
• 2012

371 strains of marine bacteria were isolated from Gwangyang bay in Korea. The dominant species were identified as Pseudomonas aeruginosa, Aeromonas hydrophila, P. fluorescens, P. paucimobilis, Chryseomonas luteola and P. vescularis. To screen marine bacteria capable of removing nutrients and organics, marine bacteria was inoculated in 10 mL of marine broth 2216 (DIFCO) with $NH_3-N$ (100 mg/L), ${NO_3}^{-}-N$ (100 mg/L), and ${PO_4}^{-3}-P$ (10 mg/L) with 1.0% (v/v), and incubated for 12 h. Results from the screening test, showed that the removal efficiencies for $COD_{Cr}$, ammonia niterogen, nitrate nitrogen, and phosphate were over 25% for 16 strains, 15% for 9 strains, 50% for 63 strains, and 15% for 80 strains, respectively. Aeromonas hydrophila, Chryseomonas indologenes, Pseudomonas diminuta, Vibrio parahaemolyticus were selected for nutrients removal experiments. For the batch test, 4 species of marine bacteria were inoculated in modified marine broth containing with nutrients($COD_{Cr}$ 250 mg/L, $NH_3-N$ 40 mg/L, ${NO_3}^{-}-N$ 40 mg/L, ${PO_4}^{3-}-P$ 10 mg/L, respectively), incubated for 10 hr and the removal efficiencies were measured.

• Korean Journal of Soil Science and Fertilizer
• /
• v.20 no.1
• /
• pp.55-61
• /
• 1987

A series of laboratory experiments were carried out to find the effects of soil organic matter contents, soil temperature, pH values, kinds and amount of nitrogen fertilizers on the denitrification-$N_2O$ gas evolution-. The results obtained were summarized as follows: 1. Denitrification rate, amount of $N_2O$ gas evolution, was influenced the order of organic matter contents>soil temperature>pH values>kinds of N-fertilizer>levels of N-fertilizer. 2. The highest dentrification rate was observed in organic matter content of 3.0%, pH values at 6.0 with application of $KNO_3$ at levels of 20 mgN/100g soil. 3. For the evolution of I mole $N_2O$ gas, averaged carbon consumption was obtained as 0.5 mole in all these experiment condition. However, the highest carbon consumption rate was obtained in organic matter contents for 1.0% with application of $(NH_4)_2SO_4$ at levels of 10 mgN/100g soil (1.06 mole) while lowest carbon consumption rate was obtained in organic matter contents for 3.0% with application of $KNO_3$ at levels of 20 mgN/100g soil (0.13 mole). 4. According to Michaelis-Menten's equation, the V/2 values for evolution of $N_2O$ gas was estimated by progress curve. The results obtained was as 550 ug for $(NH_2)_2CO$ and 1100 ug $N_2O/100g$ soil by application of $KNO_3$ in organic matter contents of 1.0% soil. On the other hand, when the application $(NH_4)_2SO_4$ the V/2 values of $N_2O$ gas was obtained as the amount of 490 ug/100g soil while V/2 values of $N_2O$ gas by application of $KNO_3$ was on the linear line in soil organic matter contents of 3.0%.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.26 no.2
• /
• pp.13-24
• /
• 2023

Sewage sludge has been widely used as an organic fertilizer in agriculture. However, sewage sludge can cause serious malodor problems resulting from the decomposition of organic compounds in anaerobic conditions. The malodor of sewage sludge mainly occurs due to a low carbon to nitrogen ratio (C/N), high moisture, and low temperature, which are ideal conditions for ammonia emissions. Therefore, in this study, we investigated the reduction of the odor-causing ammonia nitrogen (NH₃-N) in sewage sludge by co-application of microbes and methanol (MeOH). The physico-chemical properties of the municipal sewage sludge showed that the odor was mainly caused by a higher NH₃-N content (2932.2 mg L^-1). Supplementation with MeOH (20%) as a carbon source in the sewage sludge significantly reduced the NH₃-N up to 34.2% by increasing C/N ratio. Furthermore, the sewage sludge was treated with the NH₃-N reducing and plant growth promoting (PGP) bacteria Stenotrophomonas rhizophila SRCM 116907. The treatment with S. rhizophila SRCM 116907 significantly increased the seedling vigor index of Lolium perenne (10.3%) and Chrysanthemum burbankii (42.4%). The findings demonstrate that supplementing sewage sludge with methanol significantly reduces ammonia emissions, thereby mitigating malodor problems. Overall, the study highlights the potential of using a microbial and methanol approach to improve the quality of sewage sludge as an organic fertilizer and promote sustainable agriculture.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.1
• /
• pp.146-150
• /
• 2005

Two new barium vanadium borophosphate compounds, $(NH_4)_2(C_2H_{10}N_2)_6[Ba(H_2O)_5]_2[V_2P_2BO_{12}]_6{\cdot}8H_2O$, Ba- VBPO1 and $(NH_4)_8(C_3H_{12}N_2)_4[Ba(H_2O)_7][V_2P_2BO_{12}]_6{\cdot}17H_2O$, Ba-VBPO2 have been synthesized by interdiffusion methods in the presence of diprotonated ethylenediamine and 1,3-diaminopropane. Compound Ba-VBPO1 has an infinite chain anion (${[BaH_2O)_5]_2[V_2P_2BO_{12}]_6}$$^{14-}$, whereas Ba-VBPO2 has a discrete cluster anion {[$Ba(H_2O)_7][V_2P_2BO_{12}]_6$}$^{16-}$. Crystal Data: $(NH_4)_2(C_2H_{10}N_2)_6[Ba(H_2O)_5]_2[V_2P_2BO_{12}]_6{\cdot}8H_2O$, triclinic, space group P$\overline{1}$ (no. 2), a = 13.7252(7) $\AA$, b = 15.7548(8) $\AA$, c = 15.8609(8) $\AA$, α = 63.278(1)$^{\circ}$, $\beta$ = 75.707(1)$^{\circ}$, $\gamma$ = 65.881(1)$^{\circ}$, Z = 1; $(NH_4)_8(C_3H_{12}N_2)_4[Ba(H_2O)_7][V_2P_2BO_{12}]_6{\cdot}17H_2O$, monoclinic, space group C2/c (no. 15), a = 31.347(2) $\AA$, b = 17.1221(9) $\AA$, c = 22.3058(1) $\AA$, $\beta$ = 99.303(1)$^{\circ}$, Z = 4.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.22 no.2
• /
• pp.137-144
• /
• 2002

To investigate the short-term effects of N-supply form ( $NO_3\;^-$ or $NH_4\;^+$ ) and their level (0.2, 1.0 and 6.0 mM) on N assimilation and C metabolism were examined in perennial ryegrass (Lolium perenne L.). The increase in shoot fresh for $NH_4\;^+$-fed plants much less than $NO_3\;^-$ fed ones. Nitrate concentration in $NO_3\;^-$ -fed plants tended to increase with increasing the supply level, while that of $NH_4\;^+$-fed plants was nearly stable. Nitrate reductase activity (NRA) responded much quickly, showing a proportional increase within 24 h of feeding. NRA in $NO_3\;^-$ -fed plants at 72 h increased by 13.7, 40.3 and 84.0% in 0.2, 1.0 and 6.0 mM $NO_3\;^-$ -fed, but it was not changed in$NH_4\;^+$-fed plants regardless of the supply level. After 72 h of treatment the sugar accumulation in the plants supplied with 0.2 and 1.0 mM -$NH_4\;^+$fed was remarked. After 72 h of feeding, fructan hydrolysis was observed in all levels fur $NH_4\;^+$-fed plants, but only in 6.0 mM for $NO_3\;^-$ -fed plants.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.30 no.2
• /
• pp.17-28
• /
• 2022

The application of supplemental activated biochar pellet fertilizers (ABPFs) was evaluated by investigating key factors such as changes of surface paddy water and soil chemical properties and rice growth responses during the growing season. The treatments consisted of control, activated rice hull biochar pellet (ARHBP-40%), and activated palm biochar pellet (APBP-40%) applications. It was shown that the lowest NH₄⁺-N and PO₄^--P concentrations were observed in surface paddy water to the ARHBP-40%, while the NH₄⁺-N concentration in the control was abruptly decreased until 30 days after transplant in the soil. However, the lowest NH₄⁺-N concentration in the blended biochar application was 9.18 mg L^-1 at 1 day of transplant, but its ABPFs application was observed to be less than 1 mg L^-1 at 56 days after transplant. The lowest PO₄^--P concentration in paddy water treated ARHBP-40% ranged from 0.06 mg L^-1 to 0.08 mg L^-1 until 30 days after transplant among the treatments. For the paddy soil, the NH₄⁺-N concentration in the control was abruptly decreased from 177.7 mg kg^-1 to 49.4 mg kg^-1, while NO₃^--N concentration was highest, 13.2 mg kg^-1 in 14 days after transplant. The P₂O₅ concentrations in the soils increased from rice transplants until the harvesting period regardless of the treatments. The highest K₂O concentration was 252.8 mg kg^-1 in the APBP-40% at 84 days after transplant. For the rice growth responses, plant height in the control was relatively high compared to others, but grain yield was not significantly different between the control and ARHBP-40%. The application of ARHBP-40% can minimize nitrogen and phosphorous application rates into the agro-ecosystem.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.9
• /
• pp.988-994
• /
• 2011

A significant amount of nitrous oxide ($N_2O$), which is one of the serious greenhouse gases, is emitted from nitrification and denitrification of wastewater. Batch wastewater nitrifications with enriched nitrifiers were carried out under oxygen-limited condition with synthetic (without organic carbon) and real wastewater (with organic carbon) in order to find out the effect of ammonium concentration on $N_2O$ emission. Cumulated $N_2O$-N emission reached 3.0, 5.7, 6.2, and 13.5 mg from 0.4 l of the synthetic wastewater with 50, 100, 200, and 500 mg/l ${NH_4}^+$-N, respectively, and 1.0 mg from the real wastewater with 125 mg/l ${NH_4}^+$-N. The results indicate that $N_2O$ emission increased with ammonium concentration and the load. The ammonium removal rate and nitrite concentration also increased $N_2O$ emission. Comparative analysis of $N_2O$ emission from synthetic and real wastewaters revealed that wastewater nitrification under oxygen-limited condition emitted more $N_2O$ than that of heterotrophic denitrification. Summarizing the results, it can be concluded that denitrification by autotrophic nitrifiers contributes significantly to the $N_2O$ emission from wastewater nitrification.