• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.249-257
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• 2009

Surface runoff and erosion are responsible for extensive losses of top soil and agricultural productivity. In this study, a laboratory experiment was conducted to investigate the effects of different polyacrylamides (PAM) on the protection of soil from erosion and turbidity in loamy sand soil. To accomplish this, 10 and 40 kg $ha^{-1}$ of PAM were applied to the soil surface. The effects of rainfall on 10 and 20% slopes were then evaluated in the laboratory using a rainfall simulator. After air drying, the surface was subjected to rain at 30 mm $hr^{-1}$. The silt+clay of the runoff from samples treated with 10 kg PAM $ha^{-1}$ reduced by 43% and 13% when the 10% and 20% slopes were evaluated, respectively, when compared with the tap water without PAM treatment as control. The mean contents of silt+clay were reduced as the amount of PAMs applied increased at both slopes. Specifically, samples treated with 40 kg PAM $ha^{-1}$ showed reductions in the silt+clay of the runoff to 88% and 85% when the 10% and 20% slopes were evaluated, respectively, when compared to control. Furthermore, the mean turbidity of runoff in the 40 kg PAM $ha^{-1}$ treatment was reduced to 94.7% and 84.8% when the samples were subjected to 10% and 20% slopes, respectively, when compared to the control. Taken together, these findings indicate that PAM treatment will improve water pollution and agricultural productivity on sloped land via a reduction in soil erosion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.9
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• pp.1356-1363
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• 2015

The purpose of this study was to investigate the quality characteristics of instant rice noodles made from rice flour with different harvest times rice processed products. The physicochemical characteristics of three different types of rice flour were investigated, including common rice flour (CRF, harvested in 2012), stored rice flour (SRF, harvested in 2008) and CSRF (CRF mixed with SRF). Instant rice noodles were manufactured with the three types of rice flour, and their quality and sensory characteristics were investigated. The water-binding capacity of rice flour was highest in CSRF. Regarding setback on RVA pasting viscosity, SRF and CSRF showed higher values than CRF. Water absorption after cooking of instant rice noodles was highest in common rice noodles (CON). The volume after cooking of instant rice noodles increased in rice noodles with stored rice flour (SRN). Turbidity of rice noodles using CSRF (CSRN) was higher value than that of CON. In texture properties, CON displayed the highest hardness, adhesiveness, springiness, and chewiness. In the sensory evaluation, overall acceptability values of CON were significantly higher than those of other rice noodles (SRN and CSRN). It was concluded that rice noodles with stored rice flour have increased turbidity with reduced texture and overall preference. This study suggests that addition of CRF may result in significantly increased overall quality of instant rice noodles prepared by SRF.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.5
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• pp.312-320
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• 2013

Particulates in drinking water distribution system (DWDS) are mostly influenced by internal corrosion of metal pipes and sediment in pipelines due to the solution of this effect is limited. The particle size, component and properties of compounds for particulates in distributed water are different and the difference of these characteristics will be occurred by the kind of facilities, pipe condition, external factors and supply system etc. In this study, conducting the investigation of water quality in DWDS researches with particulates in the water. Monitoring sites were each water supply reservoir and the end of water supply area in DWDS. To collect particulate material at each sampling site, $47{\phi}$ glass microfiber filter type GF/C was performed using a filtration. Substances that the effect of the turbidity in the water according to particulate suspended solids and inorganic materials is due to the increasing particulates in the end of DWDS were increased. The result of compounds analysis by using X-ray diffraction (XRD) were Goethite (${\alpha}$-FeOOH), Magnetite ($Fe_3O_4$) in the end of DWDS and Quartz ($SiO_2$), Yeelimite ($Ca_4Al_6O_{12}SO_4$) at the effluent of waterworks and reservoirs. There were differences the compounds and sediments in the releasing or remaining water distribution facilities.

• Journal of the East Asian Society of Dietary Life
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• v.13 no.2
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• pp.111-121
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• 2003

Physicochemical and sensory characteristics of turnip Donchimi prepared with Chinese(DC), Korean(DK) and European origin(DE) were analyzed during fermentation at $0^{\circ}C$. Salt concentrations of Dongchimi liquid were around 1.3% during fermentation. The pH, the total acidity, Lactobacilli number and turbidity were observed during fermentation of Dongchmi. DC was fermented the most rapidly among three based on the acidity, turbidity and lactic acid bacteria number. DC maintained higher hardness in textural properties during fermentation compared to DE, although it was evaluated lower scores of appearance in sensory test, and less Hunter color a value and anthocyanin content, compared to DK or DE. DK showed the highest in anthocyanin content, Hunter color a value, and hardness. Sensory evaluation showed that the scores of color, hardness, and overall preference of Donchimi were high in the order of DK>DC>DE. Score of overall preference of turnip Dongchimi was the highest with 6.7(10 cm line scale) in DK at the 40th day of fermentation, the optimum ripening time, but the lowest with 3.5 in DE.

• Korean journal of food and cookery science
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• v.13 no.3
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• pp.286-292
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• 1997

The purpose of this study was to investigate the effect of citron (Citrus junos) on Dongchimi (watery radish kimchi) fermentation. Dongchimi with various levels (0, 1, 2, 4, 6％) of citron was fermented at 10$^{\circ}C$ for 36 days. The pH of Dongchimi decreased slowly in all samples during fermentation, however, it was slightly lower in citron-added Dongchimi. Total acidity and turbidity of Dongchimi increased gradually during formentation, in which the level of increase was greater as the ％ of added citron increased. However, the total acidity and turbidity of Dongchimt without citron increased dramatically on 36$\^{th}$/ day of fermentation, and reached the values similar to those of Dongchimi with 6% citron. Reducing sugar content increased gradually up to 15∼23 days of fermentation and decreased rapidly for the rest of the period. The content of vitamin C was much higher in citron-added Dongchimi, and especially it was 4 times higher than that of without citron at the beginning of fermentation. The number of lactic acid bacteria reached the maximum on 15$\^{th}$/ day in citron-added Dongchimi and on 30$\^{th}$/ day in Dongchimi without citron, and decreased thereafter.

• Korean journal of food and cookery science
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• v.20 no.1
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• pp.86-94
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• 2004

The purpose of this study was to investigate the changes of hardness and microstructure of Dongchimi cooked with various source of water(distilled water, purified water, Cho Jung Carbonated Natural water). This study was conducted to observe the changes of pH, total acidity, salt content, turbidity, texture and microstructure. Dongchimi cooked with source of water of water was fermented at 10$^{\circ}C$ for 46 days. The changes of pH on Dongchimi cooked with various source of water decreased in all samples during fermentation period, and then showed a slowly decrease after 12 days of fermentation. The total acidity of Dongchimi cooked with Cho Jung Carbonated Natural water was arrived slowly at best tasting condition 0.3 ∼ 0.4 point compared with other conditions. So Dongchimi cooked with Cho Jung Carbonated Natural water was continued to the best tasting condition for end of fermentation. At early stage of fermentation, the changes of turbidity of Dongchimi used Cho Jung Carbonated Natural water showed highly as compared with other test condition for 12th days of fermentation. The maximum cutting force of chinese radish of Dongchimi showed the highest value among all at the 25th day of ripening and then decreased gradually. The maximum cutting force of chinese radish of Dongchimi used Cho Jung Carbonated Natural water was the highest compared with other conditions at 25th day of fermentation. The calcium content of Dongchimi juice used Cho Jung Carbonated Natural water was observed hish at the early stage of fermentation and showed the highest value at 25th day of ripening. The calcium content of chinese radish and Dongchimi juice of Dongchimi cooked with water purifier was lower than that of Dongchimi cooked with Cho Jung Carbonated Natural water, and was higher than that of Dongchimi cooked with Distilled water at the early stage of fermentation. The magnesium content in all samples increased gradually from the early stage of fermentation. The microstructure showed disintegration appearance of middle lamella and cell wall during fermentation period.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.3
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• pp.192-197
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• 2014

Water analyses were conducted on 1,525 underground water laid in the western district of Korea's South Gyeongsang Province, from January 2007 until July 2010, according to sections, factors, fountainheads and inter-factor correlativities. The following are the results. 1. As a result of local incongruity rate, 18.2% in inland areas, coastal areas and 24.5% showed a high value comparatively. Costal areas showed high incongruity rate. 2. As a result of local incongruity rate, they were found that the total colony count and general bactria 39.9%, 42.6% showed a high in costal areas. 3. As a result of local factorial inspection, it was found that the turbidity content counted up to 0 to 0.2 NTU in 59.4% in inland areas, 60.2% in costal areas of sections, and in other 12.6%, 14.0%, it exceeded 0.5 NTU. As a result of local factorial inspection, it was found that the nitrate-nitrogen content counted up to 0 to 10 mg/L in 98.2% in inland areas, 97.6% in costal areas of sections, and in other 1.8%, 2.4%, it exceeded 10 mg/L. As regards chloride in coastal areas, water quality standards for chloride 250 mg/L exceeds the 1.4% higher then in inland areas. 4. Hardness in inland areas was closely correlated with total solids (r = 0.910), sulfate ion (r = 0.819). Also, total solids and boron (r = 0.600) showed high correlativities. On the other hand hardness in coastal areas was closely correlated with total solids (r = 0.919), chloride (r = 0.829). Also sulfate ion was closely correlated with hardness (r = 0.599), turbidity and aluminum (r = 0.635) showed high correlativities in this research.

• Membrane Journal
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• v.17 no.2
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• pp.124-133
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• 2007

In this study, we treated lake water by 2 kinds of multichannel ceramic micro filtration membranes. We could investigate effects of $N_2-back-flushing$ time (BT) and transmembrane pressure (TMP), and find optimal operating conditions. The BT were changed in $10{\sim}60$ sec, TMP in $0.6{\sim}2.0$ bar at fixed filtration time (FT) 8 min, flow rate 2.0 L/min and back-flushing pressure 2.0 bar. Also, the optimal conditions were discussed in the viewpoints of resistance of membrane fouling $(R_f)$, dimensionless permeate flux $(J/J_o)$, permeate flux (J) and total permeate volume $(V_T)$. As result, optimal back-flushing conditions for HC04 ($0.4{\mu}m$ pore size) and HC10 membrane $(1.0{\mu}m)$ were BT=10 sec and BT=20 sec, respectively. Then, higher TMP should increase the driving force, and could produce more VT. Average rejection rates of pollutants were higher than 95.4% for turbidity, $12.7{\sim}20.1%\;for\;COD_{Mn},\;0.0{\sim}6.4%\;for\;NH_3-N,\;1.9{\sim}4.6%$ for T-N and $34.9{\sim}88.4%$ for T-P.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.743-750
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• 2008

In water treatment plant the Dissolved Ozone Flotation(DOF) System may be employed because this system has various abilities, such that it can remove SS using microbubbles, and it can exert strong oxidation power in removing taste and odor, color, and microbial agents. In order to investigate effectiveness of the DOF system in water treatment, removal characteristics of various water quality parameters were observed depending on the different levels of ozone concentrations. Removal efficiencies of water quality parameters in DOF system were compared with those in DAF(Dissolved Air Flotation) system and in CGS(Conventional Gravity Settling) system. Optimum ozone dose obtained in the pilot experiments was 2.7 mg/L. With increasing ozone dose higher than 2.7 mg/L, removal rates of turbidity, KMnO$_4$ consumption, UV$_{254}$ absorbance, and TOC were reversely lowered. High concentration of ozone dissociate organic matter in water, so that increasing dissolved organic level in effluent. Removal rates of water quality parameters at optimum ozone dose were obtained, such that removal rates of turbidity, KMnO$_4$ consumption, TOC, and UV$_{254}$ asorbance were 88.9%, 62.9%, 47%, and 77.3% respectively. Removal rate of THMFP was 51.6%. For all the parameters listed above, the DOF system was more effective than the DAF system or the CGS system. It is found that the DOF system may be used in advanced water treatment not only because the DOF system is more efficient in removing water quality parameters than the existing systems, but because the DOF system is also required smaller area than the CGS system for the treatment plant.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1173-1182
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• 2000

The rapid mixing process has been considered as an important step in water treatment. Since the coagulant dispersion into raw water by rapid mixer can influence on the flocculation and filtration efficiency, many researchers have developed various devices and mixing methodologies. Until now, they focused attention on only coagulant dose, pH. rotating velocity and G value but overlooked the real turbulent flow and mixer geometry in rapid mixer. Therefore this paper questions the significance of turbulent flows in rapid mixer and focuses on the analysis of turbulent fluid in various mixer geometry with CFD(Computational Fluid Dynamics). The results of the jar-tests using various geometries indicate that the turbidity removal rate in a circular jar without baffle is higher than that of a circular with baffle. And the turbidity removal rate in Hudson jar is also founded to be higher than in the circular jar with baffle. The CFD simulation of velocity fields in jar demonstrates that the differences of removal rates among the various geometries are largely due to the formation of the different turbulent fluids fields with different geometries.