• Korean Journal of Environmental Agriculture
• /
• v.28 no.1
• /
• pp.20-24
• /
• 2009

This study was conducted to investigate the roles of co-existed organic materials (OM) with different biodegradability in composting of cattle manure in terms of $CO_2$ emission and $NH_3$ volatilization. Either sawdust (SD, low biodegradability) or rice bran (RB, high biodegradability) was mixed with cattle manure at a various rate and the amounts of $CO_2$ emission and $NH_3$ volatilization were determined periodically during 4 weeks of composting. Percentage of dry matter loss during the composting period was also calculated. The amount of $CO_2$ emitted increased with increasing rate of OM and was significantly (P<0.01) higher in the RB treatment than in the SD treatment by 43 to 122% depending on the rate of OM Accordingly, % of dry matter loss during 4 weeks of composting was higher in the RB (rang: from 35.1 % to 41.5%) than that in the SD treatments (from 18.7% to 22.6%), showing that RB is more biodegradable than SD. During the early composting period up to 8 days, negligible amount of ammonia volatilization was detected in both treatments regardless of application rates. In the RB treatment, substantial amount of ammonia volatilization was detected thereafter, however, no meaningful ammonia volatilization was observed in the SD treatment until the end of composting. Such differences could be attributed to the different properties of SD and RB. For example, the high C/N ratio of SD could enhance $NH_4^+$ immobilization and thus decrease $NH_4^+$ concentration that is susceptible to ammonia volatilization. Binding of $NH_4^+$ on to phenolic compounds of SD may also contribute to the decrease in $NH_4^+$ concentration. Meanwhile, as RB has a relatively low C/N ratio, remineralization of immobilized $NH_4^+$ could increase $NH_4^+$ concentration as high as the level for the occurrence of ammonia volatilization. Therefore, our study suggests that OM which is resistant to biodegradation can reduce $NH_3$ volatilization largely by physico-chemical pathways across the entire composting period and that easily biodegradable OM can retard $NH_3$ volatilzation via microbial immobilization in the early period of composting followed by rapid remineralization, leading to substantial volatilization of $NH_3$ in the middle stage of composting.

• Clean Technology
• /
• v.28 no.4
• /
• pp.309-315
• /
• 2022

Research was conducted to derive the optimal operation conditions and the optimal cathode for using a DSA electrode as an anode to minimize electrode consumption during the removal of nitrogen from wastewater by the electro-chemical method. Of the various electrodes tested as cathodes, brass was determined to be the optimal electrode. It had the highest NO₃-N removal rate and the lowest concentration of residual NH₃-N, a by-product when Cl is present in the solution. Investigating the effect of current density found that when the initial concentration of NO₃-N was 50 mg L^-1, the optimal current density was 15 mA cm^-2. In addition, current densities above 15 mA cm^-2 did not significantly affect the NO₃-N removal rate. The effect of electrolytes on removing NO₃-N and minimizing NH₃-N was investigated by using Na₂SO₄ and NaCl as electrolytes and varying the reaction times. When Na₂SO₄ and NaCl are mixed at a ratio of 1.0 g L^-1 to 0.5 g L^-1 and reacted for 90 min at a current density of 15 mA cm^-2 and an initial NO₃-N concentration of 50 mg L^-1, the removal rate of NO₃-N was about 48% and there was no residual NH₃-N. On the other hand, when using only 1.5 g L^-1 of NaCl as an electrolyte, the removal rate of NO₃-N was the highest at about 55% and there was no residual NH₃-N.

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2003.10a
• /
• pp.100-100
• /
• 2003

양식 산업에 있어 사육 생물의 빠른 성장은 가장 요구되는 특성이다. 특히, 선발육종을 통한 성장 개선은 사료의 효율적 이용과 연관되어 있으며, 균형 잡힌 단백질 대사 등을 통해 이루어진다. 대부분의 경골어류는 단백질 대사의 마지막 부산물로 암모니아를 생성하여 배설하며, 이를 통한 사료 내 단백질의 효율적 이용성을 비교하는 척도로 제시되어 왔다(Ming, 1985). 따라서 본 실험에서는 한국해양연구원에서 선발육종 해 온 참돔과 일본 양식산 참돔 및 이들의 교배 자손들을 대상으로 일간 먹이 공급, 절식 그리고 1회 만복 공급에 따른 암모니아성 질소 배설률을 조사하였으며, 일간 먹이 공급에 따른 각 교배 자손들의 분 배출 특성을 알아보았다. 실험어는 일본 양식산인 JPN 교배구 자손과 한국해양연구원 선발육종산인 KORDI F4 교배구 자손, 그리고 JPN$\times$KORDI F4♂ 교배구 자손을 대상으로 실시하였다. 체중이 각각 17.1$\pm$0.1 g (JPN 교배구; 그룹 1), 17.7$\pm$0.1 g (JPN♀$\times$KORDI F4♂; 그룹 2), 21.5$\pm$0.1 g (KORDI F4; 그룹 3)인 참돔 치어를 각각 15마리씩 3반복 수용하여 실험에 이용하였다. 실험어는 지름이 33 cm이고 높이가 34 cm인 둥근 투명 플라스틱 수조에 수용하고 분 수집기인 TUF column (passing effluent water through a special test tube) system을 이용 어체중의 3%에 해당하는 사료 량을 일간 세 번에 나누어 동일량을, 09시부터 17시까지 4시간 간격으로 공급한 14일째에 일간 먹이 공급에 따른 24시간 동안의 참돔 종간 잡종 치어의 총암모니아성 질소(total ammonia nitrogen, TAN) 배설률 및 분 배출률을 조사하였다. 이 조사가 끝난 후 3일간 절식시킨 다음 내인성 암모니아성 질소 배설을 조사하였으며, 이어서 1회 만복 사료 공급한 다음 이에 따른 암모니아성 질소 배설 경향을 알아보았다. 일간 먹이 공급에 따른 각 실험구의 암모니아 배설은 세 가지 계통 참돔치어 모두 먹이 섭취 후 암모니아 배설로 인한 TAN 농도가 지속적으로 증가하는 경향을 보였으며, 시간당 TAN 배설률을 적분한 결과, 그룹 1과 2 그리고 3의 일간 TAN 배설률은 각각 637.3$\pm$36.5 mg/kg fish/day, 684.3$\pm$18.5 mg/kg fish/day 그리고 772.8$\pm$17.3 mg/kg fish/day로 나타나 그룹 3의 일간 TAN 배설률이 가장 높은 결과를 보였다. 3일간 절식 후 그룹 1, 2, 그리고 2의 TAN 배설률은 각각 8.08~14.15 mg/kg fish/hr, 6.50~12.20 mg/kg fish/hr, 그리고 6.67~8.60 mg/kg fish/hr의 범위를 보여 거의 일정한 농도로 나타났다. 시간당 TAN 배설률을 적분한 결과, 그룹 1, 2 그리고 3의 일간 TAN 배설률은 각각 286.9$\pm$28.3 mg/kg fish/day, 215.7$\pm$5.5 mg/kg fish/day 그리고 179.3$\pm$7,7 mg/kg fish/day로 나타나 먹이 공급과는 달리 내인성 TAN 배설의 경우 그룹 1의 배설률이 가장 높은 결과를 보였다. 1회 만복 먹이 공급에 따른 TAN 배설 경향은 그룹 1과 2의 TAN 배설률은 먹이 공급 6시간 후 가장 높은 값인 44.19$\pm$2.90 mg/kg fish/hr와 41.70$\pm$1.40 mg/kg fish/hr을 보였고, 그룹 3에서는 4시간 후에 가장 높은 값인 31.23$\pm$1.39 mg/kg fish/day로 나타났다. 일간 먹이 공급에 따른 각 실험구의 총 분 배출량은 그룹 1의 경우 총 분 배출량은 2.17$\pm$0.1 g/kg fish와 91.15$\pm$4.53 g/kg feed로 나타났고, 그룹 2에서는 2.26$\pm$0.14 g/kg fish와 95.02$\pm$3.18 g/kg feed, 그룹 3에서는 2.81$\pm$0.73 g/kg fish와 132.85$\pm$34.0 g/kg feed로 나타나 유의적인 차이는 보이지 않았으나(P>0.05), 그룹 3의 배출 비율이 높은 것으로 나타났다. 시간 경과에 따른 분 배출 비율은 그룹 1의 경우 먹이 공급 24시간 후 총 분의 60.6%를 보여 반면, 그룹 2와 3에서는 각각 67.8%와 77.8%를 보여 그룹 1이 다른 그룹에 비해 분 배출 비율이 낮은 것으로 나타났다.

• Korean Journal of Soil Science and Fertilizer
• /
• v.14 no.1
• /
• pp.24-30
• /
• 1981

A pot Experiment and a field investigation were carried out in order to obtain some information on the ammonia volatilization and nitrogen absorption by paday rice plants in relation to the potassium application and roots growth. Results obtained were as follows ; 1. Urea application to the polt where potassium was added and rice plant was grown increased the ammonia volatilization at the beginning, but in the latter stage, the volatilization gradually decreased below that of no potassium plot. 2. Total nitrogen absorbed by rice plant, however, was much greater from the potassium added plot than no potassium and pH of the wet soil was lower in the former treatment than in the latter. 3. The application of urea presumably caused greater raise of soil pH and higher ammonia valatilization from the potassium added plot than the no potassium at the beginning, but the active growth of plants and raveneous absorption of N by the plants at the later stage of plant growth resulted in lower ammonia volatilization and lower pH in the potassium added plot than no potassium plot. 4. When the penetration of rice roots was restricted, pH of the wet soil was lower in the plot where potassium added than no potassium, and so was the ammonia volatilization. 5. Under high pH condition of paddy soil, a heavier basal application of potassium chloride or potassium sulfate may reduce the ammonia volatilization particulary in the early growth period of paddy rice when the nutrient absorption by plant is insignificant. However, under an acid normal soil, it may cause ammonia loss through raise of soil pH at the early growth of paddy rice.

• Korean Journal of Soil Science and Fertilizer
• /
• v.14 no.2
• /
• pp.70-75
• /
• 1981

The ammonia volatilization from two different soils, an acidic normal soil and a neutral tidal soil applied with different nitrogen sources was investigated through a laboratory incubation experiment conducted at about $30^{\circ}C$ for 18 days. Results obtained were summerized as follows; 1. The ammonia volatilizat ion was increased by the urea application that increased soil pH. 2. Ammonium sulfate and ammonium chloride did not raise reduced soil pH over 7.30 and showed little ammonia volatilization keeping the $pK_b$ value of 4.72-3 3. An organic fertilizer (Miweon Co. made) raised pH of the tidal land soil little more than ammonium sulfate or ammonium chloride ; however, it did not increase the ammonia volatilization as much as from other fertilizer treatment plots of the same pH, which may mean that the organic fertilizer is effective in reducing ammonia volatilization. 4. It seemed that easier volatilization of ammonia from urea may occor in ordinary soil low in original pH than from tidal soil by the application of urea which may mean that if the pH of soils are the same, greater volatilization would result from the former than the latter. 5. Application of raw straw to tidal soil lowed pH and reduced ammonia volatilization.

• KSBB Journal
• /
• v.16 no.3
• /
• pp.314-319
• /
• 2001

A nitrifier consortium immobilized in polyvinyl alcohol was used to remove ammonia nitrogen from synthetic wastewater in an airlift bioreactor. The minimum aeration rates were 0.4, 0.6, 0.8 and 1.0 vvm for 5, 10, 15 and 20% immobilized bead packing volume fraction, respectively. The efficient packing fraction and the aeration rate for ammonia nitrogen removal were 15% and 2.4 vvm, respectively. With a hydraulic retention time of 0.5hr, the removal rate and the efficiency of ammonia nitrogen removal were 1685 g/㎥$.$day and 48% at an influent ammonia nitrogen concentration of 75 g/㎥.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2000.10a
• /
• pp.223-224
• /
• 2000

대하 양식장과 같이 물의 유동이 작고, 폐쇄성이 강한 지역, 더구나 유기물 혹은 질소, 인등의 영양염류 농도가 높은 부영양화 지역에서는 저질 중의 유기물 분해에 따른 산소소비는 저질환경을 산화상태로부터 환원상태로 이동시켜 황산염 환원에 의한 황화수소가 발생한다. 따라서 황화수소의 발생은 용존산소의 저하를 나타냄과 동시에 그 자체가 강한 독성을 가지고 있으며, 질소화합물 중의 암모니아 및 아질산과 같은 형태도 양식장의 생산억제 요인으로 작용한다(Gavis and Grant, 1986; Thompson et al., 1989). 그러나, 지금까지의 이들 오염물질, 특히 황화수소에 대한 연구는 미비하며, 대부분의 연구도 성체를 중심으로 이루어지고 있다. (중략)

• Korean Journal of Soil Science and Fertilizer
• /
• v.12 no.2
• /
• pp.91-97
• /
• 1979

1. Nitrogenous compounds of-organic materials as nitrogen sources for Korean ginseng were characterized according to their solubility and chemical forms. 2. The extractable fractionation was as follows : Yakto group : non-extractable N > acid hydrolyzable N > acid nonhydrolyzable N > water sol. N, Litter group : acid hydrolyzable N > non-extractable N > water sol. N > acid non-hydrolyzable N, Bone meal : acid hydrolyzable N > water sol. N > acid non-hydrolyzable N. 3. Nitrogenous compounds in the water sol. fraction were : Yakto group and Litter group : humus N > amino acid N > nitrate N (recognized only in Yakto group) > ammonia N > hexosamine N > amide N, Bone meal : amino acid N > humus N > ammonia N > amide N. And nitrogenous compounds in the acid hydrolyzable fraction were : amino acid N > humus N ${\simeq}$ ammonia N > hexosamine N. 4. Availability was discussed about the major nitrogenous compounds (amino acid, humus and inorganic N) and the solubility.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.12 no.4
• /
• pp.293-296
• /
• 1979

The effects of temperature and salinity on tile rates of ammonia and amino nitrogen excretion, and oxygen consumption were measured for Crassostrea gigas. There was variability with temperature and salinity changes in both the rates of nitrogen excretion and the proportionality between ,ammonia and amino acids in the excreta, and also in the rates of oxygen consumption. Rates of nitrogen excretion and oxygen consumption were markedly decreased with increase in salinity, especially at high salinity-high temperature, whereas at low salinity-high temperature condition they were significantly increased. These changes are considered as the responses of physiological tolerances to the high temperature stress and the results of the metabolic temperature compensation at the low salinity-high temperature condition. Most of nitrogenous excretory products was ammonia, and large amounts of amino-nitrogen was excreted, and especially the rate of amino-nitrogen excretion was dominant at $32.5\%_{\circ}-22^{\circ}C$. The amounts of amino-nitrogen excreted by animals were decreased in the medium of high salinity and increased in the medium of low salinity through the experimental temperature. The atomic ratios of oxygen consumed to ammonia-nitrogen excreted (O: N ratio) was low at the low temperature $(15^{\circ}C)$, and was high at $22^{\circ}$ and $29^{\circ}C$ in the medium of 32.5 and $37.5\%_{\circ}$ but low in the low salinity $27.5\%_{\circ}$.

• Journal of Wetlands Research
• /
• v.17 no.4
• /
• pp.414-420
• /
• 2015

Nitrogen is one of main causes to induce eutrophication of water system and one of contaminants that must be treated for protection of water system. In this study, it was intended to identify a method to increase operation efficiency of municipal wastewater treatment plant (MWTP) by treating high concentration nitrogen. A laboratory scale reactor was operated by using sludge thickener supernatant in the MWTP. During operation of the laboratory scale reactor, it was intended to induce stable nitritation and analyze effects of related operation factors. As results, it was shown that the nitiritation could be induced artificially through control of retention time and sections where the stable nitiritation was induced were identified also. In particular, highly efficient nitrite conversion efficiency near 90% was identified in condition of 1 day retention time. Especially, it was shown that ammonium nitrogen load affected ammonium nitrogen removal efficiency and nitrite conversion efficiency. In the condition of high ammonium nitrogen load, the nitrite conversion efficiency and the ammonium nitrogen removal efficiency decreased. On the contrary in the condition of low ammonium nitrogen load, it was found that the nitrite conversion efficiency decreased. It means that control of ammonium nitrogen concentration and its retention time is needed for the nitritation. It is considered that for the sewage containing high load nitrogen in sludge treatment process as like the sludge thickener supernatant, the nitritation can be applied, which can be suggested as a modification method of MWTP.