• Journal of the Korean Applied Science and Technology
• /
• v.22 no.4
• /
• pp.379-384
• /
• 2005

In general, water treatment sludge (WTS) had high concentration of heavy metal, thus it made the reuse or recycling of WTS difficult. The optimal solidification conditions for maximum suppression of heavy metal elution from WTS were decided in this study. Under the optimal solidification conditions (i.e., temperature, $320^{\circ}C;$ ratio of WTS and MgO, 9:1; solidification time, 1hr), all of heavy metal including aluminum were not detected. Therefore there are no problems for reuse or recycling of WTS which was solidified under the optimal solidification conditions found in the study.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.30 no.1
• /
• pp.97-104
• /
• 2012

In this paper, the GPS precipitable water vapor was retrieved by estimating of GPS signal delay in the troposphere during the progress of heavy snowfall on the Gangwon Province, 2011. For this period, the time series analysis between GPS precipitable water vapor and fresh snow depth was accomplished. The time series and the comparison with the GPS precipitable water vapor and the fresh snow depth indicates that the temporal change of two variations is closely related to the progress of the heavy snowfall. Also, the periodicity of GPS precipitable water vapor using the wavelet transform method was showed a similar cycle of saturated water vapor pressure as the limitation of this study span. The result shows that the decrement of GPS precipitable water vapor was conflicted with the increment of fresh snow depth at two sites, Gangneung and Uljin. The correlation between the GPS precipitable water vapor and the saturated water vapor pressure for the event was showed a positive correlation, compare with the non-heavy snowfall periods.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2007.05a
• /
• pp.1081-1083
• /
• 2007

The study in river basin has been performed for the identify water quality impaired stream segments, to create a priority ranking of those segments, and to calculate the heavy metal ion distribution for each impaired segment based on chemical and physical water quality standards. Two methods for modeling the potential area-specific heavy metal distribution are pursued in this study. First, a novel approach focuses on distance. Heavy metal distribution can be associated with a particular small geographic area. Based on the derived estimates an distribution map can be generated. Second, the approach is used the near watershed by means of kriging interpolation algorithm. These approaches provide an alternative distribution mapping of the area. The exposure estimates from both of these modeling methods are then compared with other environmental monitoring data. A GIS-based model will be used to mimic the hierarchical stream structure and processes found in natural watershed. Specifically, the relationship between landscape variables and reach scale habitat conditions most influential found in the Abandoned mine will be explored.

• Journal of Korean Society of Water and Wastewater
• /
• v.18 no.4
• /
• pp.493-499
• /
• 2004

Rejection characteristics of heavy metals by nanofiltration membranes were investigated. Nanofiltration membranes rejected heavy metals much better than chloride, sulfate and TOC, of which concentration in synthetic wastewater was higher than that of heavy metals. To consider rejection characteristics of various metals by nanofiltration membranes, separation coefficient, which is the ratio of the metal permeation rate to the chloride ion or TOC permeation rate, was introduced. In spite of different materials and different nominal salt rejection of nanofiltration membrane used, the separation coefficients of metals were nearly the same. In particular, the separation coefficient of arsenic against chloride ion and TOC was larger than any other separation coefficient of heavy metals. These phenomena were observed in the relationship between the molar conductivity and the separation coefficient for heavy metals.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2014.06a
• /
• pp.260-261
• /
• 2014

In the present study analysed the physico chemical properties and distribution of heavy metal and also analysed the changes of heavy metal distribution by resuspension and properties of heavy metal release into sea water. From the experimental result showed sediment resuspension plays an important role in the release of heavy metals in coastal environment. Heavy metal release percentage was high in different mixing time of resuspension and different amounts of sediment due to resuspension of particulate matter.

• Journal of the Society of Naval Architects of Korea
• /
• v.42 no.4 s.142
• /
• pp.315-321
• /
• 2005

The effect of water depth on the wave making resistance performance is great where Froude number based on the water depth is close to one. The increase of wave making resistance due to the shallow water effect is evaluated by a numerical analysis in the present study. Three-dimensional Navier-Stokes and continuity equations are employed for the present study and the equations are discretized by finite difference method. The interface between water and air is determined by the level set method. In order to validate the numerical method, the change of resistance performance for Wigley hull according to the water depth is evaluated and the computed resistance coefficient is compared with measured one. The present numerical method is applied for the simulation of wave phenomena around a Ro-Pax hull form and the computed results are discussed in the resistance performance point of view.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.9 no.2
• /
• pp.1296-1300
• /
• 1967

This study was made through the utilization of heavy soil taken from the experimental plot of heavy soil in Konkuk University, Changan-dong, Sungdong-ku, Seoul. The soil used in the experiment has the following physical characteristics: 1. The soil is very compact, impervious, and unfit for any plant growth, 2. For improvement of the soil, tile drainage practice has been employed, 3. According to the general theory of tile drainage, it is unnatural that the effect of drainage is actually observed in such a soil. The followings are the results of the experiment: 1. Water moved to crosswise when the plotted soil profile was not broke. In this case the upper sloped part was dry while the bottom part was moistned. The upper part of the tile was also moistned. 2. The crosswise movement of water was not observed in the artificially broken plot of subsoil. However, the water flow from the tile was observed for long period as a result of the increase of soil void, seepage, aeration, and water holding capacity. However, the water flow from the tile in the plot of unbroken subsoil was observed only in short period and soon the flow was stopped. 3. the distance between the tile laid in the heavy soil should not exceed 10m for the efficient drainage. 4. When the pF is 2.5 in the subsoil the moisture content was between 23.97% and 28.20%. However, when the water saturated in the subsoil the moisture content was between 34.30% and 22.10%. Accordingly without the higher pF than 2.5 the water can not be absorbed and therefore the drainage can not be occured.

• Journal of the Korean Geosynthetics Society
• /
• v.13 no.1
• /
• pp.63-70
• /
• 2014

This paper describes the influence of rainfall on contamination at stream around the developed quarry. The investigation results are analyzed to evaluate the relationship rainfall and heavy metals (or water pollution). In the relationship rainfall and heavy metals, the result showed that the heavy metal contaminations are caused by boulder stone, waste residue and stone sludge, which is reacted with the direct contamination source, in the burried layer. It also found that the water flow change of stream according to the rainfall increase affected the large effect to a contamination level of heavy metal. the water pollution was increased by time changed from the rainy season to the dry season. That is, a lot of suspended solids had been discharge from the developed quarry due to rainfall increase, and then pollution level of water increases as the undercurrent of suspended solids is generated in stream due to rainfall decrease. Therefore, it analyzed that continuous causes of heavy metal contamination and water pollution in stream are materials in the burried layer and a discharge of pollution source from the developed quarry due to rainfall.

• Journal of Food Hygiene and Safety
• /
• v.19 no.3
• /
• pp.132-139
• /
• 2004

As measure against the environmental pollution, maximum efforts to improve of the environmental pollution have also been made; removal of the contaminated sediments of the bay and the coastal area, monitoring of several heavy metal levels in fishes, shell fishes, sea water and sediment, and so on. The objective of this research is to investigate how much metals are included in the sea water, sediment, fishes and shell fishes in kyeongnam coastal area. Specifically, we are investigating the relationships between the metal included in fishes and sea water, and shell fishes and sediment, and heavy metals and heavy metals respectively. Heavy metal over the studied component and area, the average concentrations of Pb, Cd, Cr and Hg in sea water were 0.0029 mg/L, 0.005 mg/L, 0.0016 mg/L and ND, those of sediment were 11.9583 mg/kg, 0.2136 mg/kg, 1.9158 mg/kg and Hg 0.0108 mg/kg, those of fishes were 0.4358 mg/kg. 0.0726 mg/kg, 1.1188 mg/kg and Hg 0.0622 mg/kg, and those of shellfishes were Pb 0.6738 mg/kg, Cd 0.2223 mg/kg, Cr 0.5516 mg/kg and Hg 0.0117 mg/kg respectively. In the relationship test, Cd was significant in the relationship between fishes and sea water, and Hg was significant in the relationship between sediment and shellfishes.

• Journal of the Korean Applied Science and Technology
• /
• v.13 no.2
• /
• pp.85-92
• /
• 1996

Chitosan itself has been prepared using chitin, one of the most abundant compounds in nature, as a starting material. We have synthesized the water-soluble chitosan derivative, N-dithiocarboxy chitosan sodium salt, through the reaction of water-soluble chitosan with carbon disulfide in the presence of alkali metal hydroxide. To elucidate this natural polymer capacity of adsorbing heavy metal ions, we have performed adsorption experiments using the water-soluble chitosan derivative various average molecular weight and of different percent contents of sulfur. The effect of pH, adsorption time and temperature on adsorption efficiency was also studied. The adsorbent derived from water-soluble chitosan of average molecular weight ranging $9,000{\sim}120,000$ was shown to have the highest capacity of adsorbing heavy metal ions. On the whole, adsorbing efficiency was increased as the reaction time goes longer and also increased as the reaction temperture goes higer in temperture range of $15^{\circ}C{\sim}45^{\circ}C$. The adsorption capacity at various pH, however, was appeared to vary depending on the heavy metal ions studied Judging from these finding, water-soluble N-dithiocarboxy chitosan sodium salt, a derivative of a biodegradable nature polymer, is believed to be a potential adsorbent for heavy metal ions since it not only is shown to lower the concentration of heavy metal ions to below the drainage quality standard, but also it would not cause acidification and hardening of soil which is one of the detrimental effects of synthetic macromolecular adsorbents present.