• Journal of Animal Science and Technology
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• v.49 no.3
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• pp.341-350
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• 2007

The present study was conducted to measure diurnal patterns in the flow of soluble non-ammonia nitrogen (SNAN) fractions in the liquid phase of digesta entering the omasum of cows fed grass-red clover silage supplemented with barley and rapeseed meal. Four ruminally cannulated cows were fed, in a 4×4 Latin square design, grass-red clover silage alone (GS) or supplemented with (on a DM basis) 6.0kg/d of barley grain, 2.1kg/d of rapeseed meal or 6.0kg/d of barley and 2.1kg/d rapeseed meal. Omasal digesta was taken using an omasal sampling system at 1.5h intervals during a 12h feeding cycle, and SNAN fractions (free AA, peptide and soluble protein) in the omasal digesta were assessed using ninhydrin assay. Dietary supplementation numerically increased the mean flow of SNAN fractions relative to GS diet despite the lack of statistical significance. Diurnal patterns in the flow of peptide entering the omasum during a 12h feeding cycle appeared to be highest immediately after feeding, declined by 10.0h post-feeding and slightly increased thereafter. In SNAN fractions, the flow of peptide was higher for supplemented diets than for GS diet throughout the feeding cycle. Based on the microbial contribution to total SNAN using 15N, diurnal patterns in the flow of dietary SNAN for dietary supplemented diets appeared to be higher compared with GS diets. Present results may conclude that peptide flow is quantitatively the most important N in SNAN fractions and that dietary supplementation can increase peptide flow entering the omasal canal.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1255-1261
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• 2005

The objective of this study was to evaluate the net flux response of nitrogen compounds (alpha-amino N, ammonia N, urea N, essential amino acids) across the portal-drained viscera (PDV), liver and total splanchnic tissues of mature wethers to increasing level of dietary fishmeal (FM) supplementation. Four wethers (average body weight, 64 kg) with chronic indwelling catheters into the portal, hepatic and mesenteric veins and the abdominal aorta were used in a 4${\times}$4 Latin square design. A basal diet consisting of 0.7 hay and 0.3 concentrate was fed twice daily with a fixed amount at 1.4 times maintenance energy (1.3 kg/day on a dry matter basis). The supplementation proportion of FM as treatment was 0, 0.03, 0.06 and 0.09 to the amount of the basal diet to contain 119, 137, 154 and 170 g crude protein per kg dietary dry matter, respectively. Blood flows through PDV and liver did not differ (p>0.05) among the treatments. Both net PDV release and hepatic uptake of alpha amino acid N increased linearly (p<0.05) in response to increased dietary FM, which resulted in similar total splanchnic release of alpha-amino N among the treatments. Similarly, increased dietary FM increased net PDV absorption and hepatic removal of ammonia N linearly (p<0.05). Hepatic synthesis and total splanchnic release of urea N increased linearly (p<0.01) with increased dietary FM, but PDV uptake of urea N did not respond to increased dietary FM. Linear regression equations between the increases in FM N intake and PDV net flux indicated that 0.34 and 0.30 of FM N was absorbed in the form of alpha-amino N and ammonia N, respectively. The results demonstrated that FM supplementation provides more alpha-amino N than ammonia N to the liver, but the alpha-amino acid N absorption is less than the expected metabolizable protein N from FM supplementation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.2
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• pp.163-169
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• 2003

The floating bead filter was tested for treatment of aquacultural water in a pilot-scale recirculating aquaculture system. Performance of floating bead filter on the removal of total suspended solids (TSS) and the treatment of nitrogen sourer such as total ammonia nitrogen (TAN), nitrite nitrogen and nitrate nitrogen were evaluated. The system was stocked with Nile tilapia at an initial rearing densities of $5\%\;and\;7\%$ over 30 days. The average TSS removal rates were $43.0\;g/m^2{\cdot}day\;and\;39.5\;g/m^2{\cdot}day$ for rearing density of $5\%\;and\;7\%$, respectively. As rearing density increased from $5\%\;to\;7\%$. the TAN removal efficiency decreased from $22.0\%\;to\;17.7\%$. At the rearing densities of $5\%\;and\;7\%$, the average TAN removal rates and removal efficiencies were $38.8\;g/m^2{\cdot}day,\;15.6\%\;and\;37.8\;g/m^2{\cdot}day.\;17.7\%,$ respectively. The average TAN removal rate was $37.8-38.8\;g/m^3{\cdot}day.$ The oxygen consumption by floating bead filter was higher than theoretical oxygen consumption rate by nitrification.

• Journal of Animal Environmental Science
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• v.6 no.2
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• pp.65-72
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• 2000

This study was conducted to investigate the effects of artificial filaments equipped in the aeration tank of aerobic·fermentation system on the removal efficiency of swine wastes which were fermented an aerobically and thus containing high nitrogen. Two aerobic fermentation system each consist4s of 4 tanks ; storage tank, 1st and 2nd aeration tank and settling tank were run before and one or three weeks after equipment of artificial filament in the aeration tanks. Total solids concentration tended to increase by aerobic fermentation in all running periods. However, decreased(P<0.05) total nitrogen concentration was shown three weeks after the equipment of artificial filament. Ammonia nitrogen concentration also largely decreased(p<0.05) in both running periods of one and three weeks after equipment of artificial filaments. These results suggest that the artificial filaments may improve the removal efficiency of nitrogen in swine wastewater containing high nitrogen during aerobic fermentation.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.273-279
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• 2006

The performance of an autothermal thermophilic aerobic digestion (ATAD) system was studied to determine if nitrogen loss, as ammonia, was affected by an exhaust gas condenser. The system was run with and without a condenser while treating $8m^3$ of piggery slurry for 8 days. The system with a condenser (SWC) maintained the reactor temperatures above $40^{\circ}C$ for 2 days during the 8 days run, while the system without a condenser (SWOC) remained above $40^{\circ}C$ for 6 days. The SWC maintained the reactor temperatures mostly at mesophilic conditions while the SWOC at thermophilc conditions. Differences in operation conditions for the two runs were mainly caused by differences in atmospheric temperatures. Soluble chemical oxygen demand (SCOD) and volatile solids (VS) removal efficiencies of the SWC (SCOD: 62%, VS: 41%) were higher than those of the SWOC (SCOD: 40%, VS: 20%). The total Kjeldal nitrogen (TKN) removal efficiency of the SWC (7%) was less than that of the SWOC (25%). The concentration of total volatile fatty acids (VFA) in the SWC was observed to be lower than the threshold value of 0.23 g total VFA/L after 6 days, while the SWOC progressed below the threshold value after 3 days. No offensive odor emissions were observed in either run, which suggest that the use of the ATAD system may be a good odor removal strategy.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.436-442
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• 2017

This study was conducted to develop a wastewater treatment system to remove organic matter, nitrate nitrogen, and phosphate ion in synthetic wastewater. COD was removed almost 100% by the oxidation reaction of HClO and nitrate nitrogen was reduced to ammonia by electrolysis treatment, but ammonia was reoxidized into nitrate nitrogen by HClO treatment. Ammonia was removed almost 100% by heating evaporation and no ammonia was reoxidized into nitrate by HClO treatment. Phosphate ion could be removed by precipitation treatment by forming metal complex according to pH. Through electrolysis treatment and HClO treatment, removal efficiencies of COD 99.5%, nitrogen 97.3% and phosphorus 91.5% were obtained.

• Journal of the Korean Applied Science and Technology
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• v.23 no.2
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• pp.130-136
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• 2006

Theoretical total nitrogen removal efficiency and reactor volume ratio in oxic-anoxic-oxic system can be found by influent water quality in this study. The influent water quality items for calculation were ammonia, nitrite, nitrate, alkalinity, and COD which can affect nitrification and denitrification reaction. Total nitrogen removal efficiency depends on influent allocation ratio. The total nitrogen removal follows the equation of 1/(1+b). Optimal reactor volume ratio for maximum TN removal efficiency was expressed by those influent water quality and nitrification/denitrification rate constants. It was possible to expect optimal reactor volume ratio by the calculation with the standard deviation of ${\pm}14.2$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.367-372
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• 2000

A series of experiment was conducted to investigate the relationship between ammoia removal rate and ammonia loading rates in seawater filtering system using rotating biological contactor (RBC). In this experiment, RBC system was consisted of rotating polyvinyl film disks, which provided $12 m^2$ of total effective surface area in $0.075 m^3$ of volume. $NH_4Cl$ was added by $10{\~}150 g$ as a ammonia nitrogen source to determine ammonia removal rate in RBC system. Relationship between time required for ammonia removal (y: hour) and nitrogen inputted ($x: NH_4-N mg/l$) in RBC system was as followed: $y=3.51+7.76 lnx (r^2=0.936)$. At ammonia concentration $2 mg/l$, it took 10 hour for removal of ammonia in the RBC system. However, at ammonia concentration of $5 and 16.5 mg/l$, it took 16 and 27 hours, respectively. There was a decreasing tencency of an increasing ammonia in the rearing water. Finally, the ammonia removal rate in the RBC system increased with the rise of total ammonia concentration up to $16.5 mg/l$.

• Food Science and Biotechnology
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• v.14 no.5
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• pp.645-650
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• 2005

To reduce ammonia-like odor in chondroitin sulfate, longnose skate (Rasa rhina) cartilage was processed by washing, autoclaving, and alkali pretreatments. Content of total volatile basic nitrogen (TVB-N), index of ammonia-like odor, of raw skate cartilage without pretreatment was 254 mg/100 g, whereas those of skate cartilage pretreated with washing and autoclaving increased to 630 and 636 mg/100 g, respectively. TVB-N of skate cartilage pretreated with sodium hydroxide sharply decreased to 15 mg/l00 g at optimal condition of 0.12 M and 3.6 volume of NaOH, as determined by surface response methodology of central composite design for optimization. Alkali pretreatment resulted in 97.6% deodorizing. Washing and autoclaving pretreatments had almost no effect on the yield of chondroitin sulfate (approximately 30%), whereas decreased to 16.0% after alkali pretreatment, showing chondroitin sulfate of skate cartilage as chondroitin sulfate C.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.1
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• pp.5-14
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• 2010

A pilot-scale biological aerated filter (BAF) was operated with an anaerobic, anoxic and oxic zone at $23{\pm}1^{\circ}C$. The influent sCOD and total nitrogen concentrations in the feedwater were approximately 250 mg/L and 35 mg N/L, respectively. sCOD removal at optimum hydraulic retention time (HRT) of 3 hours with recirculation rates of 100, 200 and 300% in the column was more than 96%. Total nitrogen removal was consistently above 80% for 4 and 6 hours HRT at 300% recirculation. For 3 hours HRT and 300% recirculation, total nitrogen removal was approximately 79%. Based on fitting results, the kinetic parameter values on nitrification and denitrification show that as recirculation rates increased, the rate of ammonia and nitrate transformation increased. The ammonium loading rates for maximum ammonium removed were 0.15 and 0.19 kg $NH_3$-N/$m^3$-day for 100% and 200% recirculation, respectively. The experimental results demonstrated that the BAF can be operated at an HRT of 3 hours with 200 - 300% recirculation rates with more than 96 % removal of sCOD and ammonium, and at least 75% removal of total nitrogen.