• Journal of Korean Society of Water and Wastewater
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• v.27 no.6
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• pp.703-709
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• 2013

Among many microalgae cultivation types, heterotrophic culture with low cost carbon sources and energy saving culture method is crucial. A result of estimating the effects of pH on wastewater treatment using heterotrophic growing microalgae Chlorella sorokiniana shows that there was no difference in microalgae growth amount and nitrogen, phosphorus removal rate by wide range of pH(5 ~ 9). From pH 5 to 9, total nitrogen, phosphorous and glucose removal rates were 10.5 mg-N/L/d, 2 mg-P/L/d, 800 ~ 1000 mg/L respectively. This study reveals that C. sorokiniana cannot metabolite glycerol heterotrophically, however, glucose and acetate were proper carbon sources for growth and T-N, T-P and TOC removal. This research highlights the potential of heterotrophic microalgal growth with wastewater treatment plant with wide range of pH and carbon sources.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.2
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• pp.197-202
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• 1999

Three barrows weighing 45.0 kg, fitted with simple T-cannulas in both the duodenum and terminal ileum, were assigned to diets in a $3{\times}3$ Latin Square design experiment to determine the effect of two calcium levels (0.8% vs 0.4%) on phytase activity and nutrient balance in growing pigs. The control diet contained 0.8% calcium, with no added inorganic phosphorus (0.45% total phosphorus) and no added phytase. The two additional experimental diets contained microbial phytase (750 phytase units/kg) and supplied either 0.8% or 0.4% calcium. With added microbial phytase, ileal and total tract digestibility of rotal phosphorus were improved by 20.9 and 13.8 percentage units, respectively (p=0.01). The apparent duodenal and ileal digestibility of phytate phosphorus were increased by 51.8 and 49.7 percentage units (p=0.01). Lowering dietary calcium in the presence of microbial phytase increased the digestibility of phytate phosphorus by an additional 10.9 (p=0.001) and 5.7 percentage units for duodenal and ileal digestibility, respectively. Supplementation with microbial phytase significantly reduced fecal excretion of nitrogen and phosphorus and increased the percentage of these nutrients retained by the pig. Lowering dietary calcium further increased the percentage of dietary phosphorus retained. Overall, reducing dietary calcium appeared to increase the effectiveness of added microbial phytase in degrading phytate phosphorus. As a result, care should be taken to avoid high levels of dietary calcium when supplementing swine diets with microbial phytase.

• Korean Journal of Poultry Science
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• v.30 no.2
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• pp.113-118
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• 2003

In this study, broilers were raised up to 6 weeks of age in a single room to determine if different levels of dietary protein or addition of aluminum sulfate[alum, $Al_2$(SO$_4$)$_3$ㆍ14$H_2O$] to the litter affected growth performance, production of ammonia(NH$_3$) and soluble phosphorus(SP) content of the litter.The experimental treatments consisted of six treatments in a 2x3 factorial arrangements: T$_1$＝23% protein ＋ 0.2% alum to litter; T$_2$＝21% protein ＋ 0.2% alum to litter; T$_3$＝19% protein ＋ 0.2% alum to litter; T$_4$＝23% protein ＋ no alum; T$_{5}$＝21% protein ＋ no alum; T$_{6}$＝19% protein ＋ no alum. For broiler performance, there was no effect of alum addition to the litter, but the dietary protein levels significantly affected feed intake from days 22 to 42(P<0.05) and day 0 to 42(P< 0.05), weight gain during all periods(P<0.05 or 0.01), and feed:gain from day 0 to 21(P<0.05) and day 0 to 42(P<0.05). Alum addition to the litter did not affect body weight at 21 and 42 days, but dietary protein levels has a significant effect on it at both 21(P<0.0l) and 42 days(P<0.05). Alum addition only affected ammonia production at weeks 3(P

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.639-646
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• 2022

The present experiment was conducted to assess the effect of Buttiauxella-derived phytase in finishing pigs fed corn/soybean meal diets with an increase in the calcium (Ca)/total phosphorus (P) (Ca/tP) ratio and a reduction in net energy on the growth performance and nutrient digestibility on the finishing pigs. A total of 90 crossbred ([Yorkshire × Landrace] × Duroc) finishing pigs with an average initial body weight (BW) of 56.94 ± 2.43 kg were used for an 11-week feeding trial. The pigs were randomly allotted to one of three dietary treatments (six replication/treatment and five pigs/pen) in a randomized complete block design according to their BW and gender. Dietary treatments consisted of supplementation of phytase (0.05, 0.07, and 0.1% in the control, Trt1 and Trt 2 diets, respectively) maintaining the Ca/tP ratio (1.67 : 1, 1.84 : 1, and 2.19 : 1 in control, Trt1 and Trt 2 diets, respectively) and reducing the net energy by 1% in Trt1 and Trt2 diets compared with the control diet. The results showed that dietary supplementation with phytase in the energy-reduced diet had a similar (p > 0.05) effect on the BW, average daily gain, average daily feed intake, and gain/feed ratio of the finishing pigs. Also, there were no effects (p > 0.05) of treatment matrixes on the nutrient digestibility of dry matter, nitrogen calcium, phosphorus, and gross energy. In conclusion, the increase of phytase and Ca/tP ratio and the reduction of net energy in the corn/soybean meal diet resulted in comparable growth performance and nutrient digestibility of finishing pigs relative to pigs fed the control diet.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.619-626
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• 2014

In this paper, it was constructed the halophyte Mesocosm experimental which was used tidal flat and dredged sediment as a substrate material. Depending on the vegetation and substrate material of Mesocosm, Mesocosm A(tidal flat sediment + Salicornia herbacea), Mesocosm B (only dredged sediment), Mesocosm C(dredged sediment + Salicornia herbacea). Monitoring was carried out of Warter quality factots(Chemical Oxygen Demand(COD), Total Nitrogen(T-N), Total Phosphorus(T-P), water temperature, salinity), Sediment factors(Chemical Oxygen Demand(COD), Total Nitrogen(T-N), Total Phosphorus(T-P)) and growth of Salricornia herbacea. Habitat Stability Index of vegetation was calculating by using the monitoring results. HSI of Mesocosm C was calculated from 0.87 to 0.95 as compared to the relatively high HSI in Mesocosm A, it was evaluated to be able to be used in the restoration and construction of the coastal salt marsh with dredged sediment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.387-392
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• 2006

There have been several problems in treating shipboard sewage due to special environmental conditions of ship, such as limited space, rolling and pitching, change of temperature and so on. It was suggested that Sequence Batch Reactor (SBR) might be suitable process for overcome these problems in terms of small size, high capacity of treating wastewater and full automation. In this study a SBR process was employed for biological treatment of organic wastes in the shipboard sewage. This process was able to remove nitrogen and phosphorus as well as organic matter efficiently. More than 95% of chemical oxygen demand(COD) were removed. In addition, about 97% of total nitrogen (T-N) was reduced. The total phosphorus(T-P) reduction averaged 93%. A disturbance operation caused by the treatment of Methylene Blue Active Substances(MBAS) was not observed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.315-320
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• 2006

There have been several problems in treating shipboard sewage due to special environmental conditions of ship, such as limited space, rolling and pitching, change of temperature and so on. It was suggested that Sequence Batch Reactor (SBR) might be suitable process for overcome these problems in terms of small size, high capacity of treating wastewater and full automation. In this study a SBR process was employed for biological treatment of organic wastes in the shipboard sewage. This process was able to remove nitrogen and phosphorus as well as organic matter efficiently. More than 95% of chemical oxygen demand(COD) were removed. In addition, about 97% of total nitrogen (T-N) was reduced. The total phosphorus(T-P) reduction averaged 93%. A disturbance operation caused by the treatment of Methylene Blue Active Substances(MBAS) was not observed.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.3
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• pp.41-50
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• 2017

The purpose of this study were to evaluate the effect of best management practices (BMPs) of Haean highland agricultural catchment ($62.8km^2$) under future climate change using SWAT (Soil and Water Assessment Tool). Before future evaluation, the SWAT was setup using 3 years (2009~2011) of observed daily streamflow, suspended solid (SS), total nitrogen (T-N), and total phosphorus (T-P) data at three locations of the catchment. The SWAT was calibrated with average 0.74 Nash and Sutcliffe model efficiency for streamflow, and 0.78, 0.63, and 0.79 determination coefficient ($R^2$) for SS, T-N, and T-P respectively. Under the HadGEM-RA RCP (Representative Concentration Pathway) 4.5 and 8.5 scenarios, the future precipitation and maximum temperature showed maximum increases of 8.3 % and $4.2^{\circ}C$ respectively based on the baseline (1981~2005). The future 2040s and 2080s hydrological components of evapotranspiration, soil moisture, and streamflow showed changes of +3.2~+17.2 %, -0.1~-0.7 %, and -9.1~+8.1 % respectively. The future stream water quality of suspended solid (SS), total nitrogen (T-N), and total phosphorus (T-P) showed changes of -5.8~+29.0 %, -4.5~+2.3 %, and +3.7~+17.4 % respectively. The future SS showed wide range according to streamflow from minus to plus range. We can infer that this was from the increase of long-term rainfall variability in 2040s less rainfalls and 2080s much rainfalls. However, the results showed that the T-P was the future target to manage stream water quality even in 2040s period.

• KCID journal
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• v.14 no.1
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• pp.57-66
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• 2007

Temporal changes in total nitrogen (T-N) and phosphorus (T-P) concentrations in paddy floodwater in response to fertilization under rain-shielding pot and small-scaled field conditions were investigated. On the basis of the changing patterns, suggestions for the use of fertilization factors, such as days after fertilization, in developing models for the estimation of T-N and T-P loads from paddy fields were made. Total N concentration was susceptible to fertilization, showing a peak concentration right after fertilization followed by a decreasing pattern with the elapse of days after fertilization. The decreasing pattern of T-N concentration followed the first- order kinetics, indicating that the models are likely to be an exponential equation using days after fertilization as an independent variable. Comparison between the pot and field experiments conducted with soils different in soil fertility revealed that indigenous soil N concentration significantly affected T-N concentration, and this suggests that soil N status can be used as the second variable for the models. Meanwhile, temporal changes in T-P concentration did not respond to P fertilization as sensitively as T-N. In combination with other published results, our study suggests that rainfall intensity and other factors associated with farming activities that are likely to cause disturbance of soil particles containing P may be used as possible variables for the models.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.603-606
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• 2003

This study was carried out to investigate the effects of T-P concentrations in irrigation water on the growth, yield, and grain quality of rice. It acquire fundamental knowledges to set up irrigation water quality standards. The pot experiment was conducted with 5 treatments using irrigation waters. It consisted of various total phosphorus concentrations(control, 1, 2, 5, 10mg/L) and replicated four times with randomized block design. The results of this study showed that as T-P concentrations in irrigation water increases, plant height tended to increase. Dry weight of rice plant at T-P 10mg/L was significantly higher than the control. However, T-P in irrigation water did not affect plant height, tiller number, plant dry weight, yield, and quality of rice.