• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2004.11a
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• pp.97-97
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• 2004

• Journal of Korean Society of Environmental Engineers
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• v.32 no.12
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• pp.1076-1086
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• 2010

Soil remediation technologies were experimented to evaluate whether the technologies could be used to apply remediation of contaminated marine sediment. In this research, marine sediments were sampled at "Ulsan" and "Jinhae" where remediation projects are considered, and then the possibility of heavy metal removal was evaluated throughout the technologies. Heavy metal concentration of silt and clay fraction was higher than that of sand fraction at "Ulsan". Heavy metal removal of the silt and clay fraction was arsenic (As) 81.5%, mercury (Hg) 93.8% by particle separation, cadmium (Cd) 72.2%, mercury (Hg) 93.8% by soil washing technology, cadmium (Cd) 70.8%, lead (Pb) 65.6% by another soil washing technology. Based on experimental results, tested particle separation and soil washing technologies could be used to remove heavy metals of sand fraction and silt and clay fraction. Heavy metal removal by soil washing technology which was composed of separation, washing and physical or chemical reaction by additives such as acid, organic solvents was more effective comparing to that of particle separation. Since heavy metal concentration of all treated samples was suitable for national soil standards, all the tested technologies were could be used not only to remove heavy metals of marine contaminated sediment but also to reuse treated samples in land.

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.317-330
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• 2009

To diminish the levels of organic matters, a novel S-CROM (continuous removal of organic matters in the stream system using freshwater bivalve), was developed and applied to the polluted stream discharging from the wastewater treatment plant, Pocheon stream, Pocheon city (Korea). Major pollutants of the stream were human population and industrial wastewaters. The study was conducted at a small dam constructed within the stream, often called 'bo', and designed with four tanks; no mussels and no sediment (negative control), no mussels and sediment (positive control), 30 mussels and sediment (D1), and 60 mussels and sediment (D2). Physicochemical and biological parameters were measured at 12 hours interval (day and night) after mussel stocking. Results indicated that Anodonta woodiana Lea (D2) clearly removed approximately 72% of chl-$\alpha$ and 57% of suspended solids on second day, however, there were no differences in removal activities between animal densities (P>0.5). Dislike a laboratory CROM system, which previously developed, there were no huge release of nutrient ($NH_3$-N and SRP), due perhaps to the higher flow rate and the lower animal density. Therefore, we may suggest that if we can determine the relevant current and the animal density considering the stream state, an S-CROM system has a strong potential to water quality improvement of eutrophic streams. Some characteristics on both CROM and S-CROM were compared.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.490-496
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• 1996

This study was undertaken in order to elucidate the elimination of phenthoate residues by washing and cooking processes of rice which if the most important food crop in Korea. When contaminated rice was washed with distilled water three times, the removal rate of total phenthoate was 51%. The removal rate in the successive washings was 37.3% (wash filtrate 7.8%, wash sediment 29.5%) in the first, 14.3% (wash filtrate 6.2%, wash sediment 8.1%) in the second and 8.9% (wash filtrate 5.8%, wash sediment 3.1%) in the third washings. More than half of the residue was removed by the first washing and most residues were found in the sediment rather than in the filtrate of the rice washings. The residue rate of phenthoate after cooking by an electric rice cooker was 41%, indicating that the removal rate after cooking was 59%, because phenthoate is thermally stable at the cooking temperature. In conclusion, phenthoate residues contaminated in rice grains are grcatly removed in the washing process and it is desirable to wash the grains before cooking in order to decrease the hazards from pesticide residues such as phenthoate. Reduction factor of phenthoate in rice cooking is proposed to be 0.4.

• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.267-275
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• 2018

The dredged sediment management system was developed to have an objective, quantitative and scientific decision for the optimum removal time of dredged sediments behind debris barrier and was set up at the real site. The dredged sediment management system is designed and developed to directly measure the dredged sediments behind debris barrier in the field. This management system is composed of Data Acquisition System (DAS), Solar System and measurement units for measuring the weight of dredge sediments. The weight of dredged sediments, the water level and the rainfall are measured in real time using the monitoring sensors, and their data can be transmitted to the office through a wireless communication method. The monitoring sensors are composed of the rain gauge to measure rainfall, the load cell system to measure the weight of dredged sediments, and water level meter to measure the water level behind debris barrier. The management criteria of dredged sediments behind debris barrier was suggested by using the weight of dredged sediments. At first, the maximum weight of dredged sediments that could be deposited behind debris barrier was estimated. And then when 50%, 70% and 90% of the maximum dredged sediments weight were accumulated behind debris barrier, the management criteria were divided into phases of Outlooks, Watch and Warning, respectively. The weight of dredged sediments can be monitored by using the dredged sediment management system behind debris barrier in real time, and the condition of debris barrier and the removal time of dredged sediments can be decided based on monitoring results.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.3
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• pp.11-17
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• 2014

We investigated the applicability of steel slag as a capping material in order to minimize phosphorus(P) release into seawater. Steel slag is a byproduct from the iron and steel industries and the use of steel slag has some advantages in respect of both cost and environmental concern. P removal by steel slag were studied in a batch system with respect to changes in contact time and initial concentration. Kinetic adsorption data were described well by pseudo 2nd order model, indicating rate limiting step for P adsorption to steel slag is chemical sorption. Equilibrium adsorption data fitted well to Langmuir isotherm model which describes for single layer adsorption. The maximum P adsorption capacity of steel slag was 7.134 mg-P/L. Increasing the depth of steel slag produced a positive effect on interruption of P release. More than 3 cm of steel slag was effective for blocking P release and 5 cm of steel slag was recommended as the depth for capping of P contaminated marine sediments. Increasing P concentration and flow rate had a negative effect on P removal ratio. It was concluded that the steel slag has a potential capping material for blocking P release from marine sediments.

• Journal of Food Hygiene and Safety
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• v.19 no.3
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• pp.132-139
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• 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 Korean Society of Environmental Engineers
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• v.31 no.4
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• pp.256-262
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• 2009

The use of hydrodynamic separator is becoming increasingly popular for suspended solids reduction in urban storm runoff. This study is a laboratory investigation of the use of Vortex Screen to reduce the solids concentration of synthesized storm runoff. The synthesized storm runoff was made with water and addition of particles; manhole sediment, road sediment, fly ash, and ployvinyl chloride powder. Vortex Screen was made of acryl resin with 250 mm of diameter and height of 700 mm. To determine the removal efficiency for various influent concentrations of suspended solids (SS) and chemical oxygen demand (COD), tests were performed with different operational conditions. The samples were taken simultaneously at the influent storage tank and effluent tank, and measured SS and COD concentrations. The ranges of surface loading rate were 110 to 1,550 $m^3/m^2$/day, and influent SS concentrations were varied from 141 to 1,986 mg/L. This paper was intended to evaluate the effect of inlet baffle and the ratio of underflow to overflow ($Q_U/Q_O$) on particle separation efficiency for various particle size using Vortex Screen. It was found that when increase of $Q_U/Q_O$ from 10% to 20%, SS removal efficiency was increased about 6%. The range of SS and COD removal efficiencies of road sediment particle size 125<$d_p$<300 ${\mu}m$ were 68.0~81.0%, 53.1~71.9%, respectively. Results showed that SS removal efficiency with inlet baffle improved by about 10~20% compared without inlet baffle.

• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.295-303
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• 2000

The water clarification efficiency was examined in a shallow wetland where dense vegetation was formed naturally in an abandoned paddy field. And, also two enclosure experiments were carried out to measure the effects of materials exchange between sediment and the overlying water with the existence of vegetation and accumulated litter. The hydraulic retention time of wetland was regulated in 1.2 day. The removal rates of SS (56%) and $NO_3-N$ (61%) were high, considering its short retention time. However, removal efficiencies of VSS (28%), COD (14%), DOC (1%),and TP (0.2%) were relatively lower. This low removal efficiencies were thought to be due to the release of dissolved form of organic matter and phosphorus from the sediment. Most of constituents except nitrate were higher in the enclosure at the beginning of enclosure installation than that of the outflowing water from wetland. And then, it has fluctuated and decreased with time. The wetland was in equilibrium state of settling, accumulation of organic debris, and regeneration of dissolved material from sediment. So ultimately high primary production by dense vegetation in the wetland may be the reason of unfavorable or low treatment efficiency of wetland after many years of operation for wastewater treatment. However, the water quality of effluent from the wetland showed smaller variation and better condition than that of inflow, especially during storm events. It can be concluded that this wetland is suitable for the improvement of water quality from nonpoint sources.

• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.1031-1037
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• 2006

In order to improve water quality of the Juam Lake, a constructed wetland was implemented and operated for 2 years with the effluent of sewage treatment plant and diffuse pollutant discharged from agricultural area. During the summer season, average removal efficiencies for BOD and SS were 15.8% and 39.4%, respectively. Due to the mixed effect of vegetation, soil microbes and sediments, the higher nutrient removal efficiencies were obtained: average T-N and T-P removal efficiencies were 64.2% and 71.7%, respectively. The concentration of sediment was increased initially, and maintained constant throughout monitoring period. The highest nitrogen and phosphorus uptake were observed in Phragmites japonica. The nitrogen uptake was estimated as 0.235 DW mg/g while phosphorus uptake was estimated as 2.059 DW mg/g.