Young-Ik Choi
Dong-a University
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Featured researches published by Young-Ik Choi.
Desalination and Water Treatment | 2015
Yongsun Choi; Young-Ik Choi; Tuan-Ho Le; Sangmun Shin; Dae-Young Kwon
AbstractGroundwater is one of the major sources of water supply for domestic, industrial, and agricultural purposes. Intensive water resources constructions in past decades have had huge impacts on hydrological systems. Recently, groundwater dams have received consistent attention as alternative water supply systems with minimal environmental destructions. Groundwater dams are usually of smaller capacity and costs much less compared with river dams. Therefore, it can be a very attractive solution especially for those small provincial cities suffering severe months-long drought every year. As an application of computer science technologies develops, a number of information systems are utilized for the sustainable development for water resources. Recently, groundwater dams have received consistent attention as alternative water supply systems with minimal environmental destruction. Since groundwater dams are constructed at the height close to sea level, optimal water-pumping strategy based on accurate forec...
Journal of Environmental Sciences-china | 2011
Ho-Eun Choi; Jin-Hee Jung; Young-Rip Han; Dae-Yong Kim; Byung-Gil Jung; Young-Ik Choi
The objectives of this study are to examine the processing of oils contamination soil by means of using a micro- nano-bubble soil washing system, to investigate the various factors such as washing periods, the amount of mi- cro-nano bubbles generated depending on the quantity of acid injection and quantity of air injection, to examine the features involved in the elimination of total petroleum hydrocarbons (TPHs) contained in the soil, and thus to eval- uate the possibility of practical application on the field for the economic feasibility. The oils contaminated soil used in this study was collected from the 0~15 cm surface layer of an automobile junkyard lo- cated in U City. The collected soil was air-dried for 24 hours, and then the large particles and other substances contained in the soil were eliminated and filtered through sieve No.10 (2 mm) to secure consistency in the samples. The TPH concentration of the con- taminated soil was found to be 4,914~5,998 mg/kg. The micronano-bubble soil washing system consists of the reactor, the flow equalization tank, the micronano- bub- ble generator, the pump and the strainer, and was manufactured with stainless material for withstanding acidic phase. When the injected air flow rate was fixed at 2 L/min, for each hydrogen peroxide concentrations (5, 10, 15%) the removal percents for TPH within the contaminated soil with retention times of 30 minutes were respectively identi- fied as 4,931 mg/kg (18.9%), 4,678 mg/kg (18.9%) and, 4,513 mg/kg (17.7%). And when the injected air flow rate was fixed at 2 L/min, for each hydrogen peroxide concentrations (5, 10, 15%) the removal percents for TPH within the contaminated soil with retention times of 120 minutes were respectively identified as4,256 mg/kg (22.3%), 4,621 mg/kg (19.7%) and 4,268 mg/kg (25.9%).
Journal of Environmental Sciences-china | 2011
Jin-Hee Jung; Sung-Ho Jang; Young-Ik Choi
The objectives of this research are to investigate the proper coagulation conditions which are a type and doses of coagulants, mixing conditions (velocity gradients and mixing times), pH and so on through Jar-test, to evaluate the flux variations, permeate, backwashing according to characteristics of pretreatment of the wastewater by means of MF membranes for river maintenance water reuse. The effluent water from B-city K-sewage treatment plant are used for this research. Turbidity and suspended solids(SS) are 14.2 NTU and 10.4 mg/L respectively. This condition causes fouling for membrane process. The flux decline could be reduced when coagulation pretreatment was carried out. Optimal coagulations PAC which are commonly used in the sewage treatment plant was observed in this research. The results indicate that an optimal coagulation dose and pH are 80 ppm and pH of 7 respectively, but coagulation efficiency was lower at strong acid or strong base. Results showed that continuous and steady operations in membrane separation process by means of the effective removal of organic matter and turbidity with coagulation pretreatment of sewage secondary effluent were achieved.
Journal of Life Science | 2016
Young-Hwa Kim; Kyoung-Rim Han; Heejae Hwang; Hyukjun Kwon; Yerim Kim; Kwonwoo Kim; Heejoo Kim; Myunghwa Son; Young-Ik Choi; Nak-Chang Sung; Yeonghee Ahn
/l. Genomic DNA was isolated from the en-riched culture and its inoculum (activated sludge), and used for PCR-DGGE analysis of 16S rRNA genes. Microbial compositions of the enrichment culture and the activated sludge were different, as determined by their different DGGE profiles. The difference in DGGE banding patterns suggests that environmental conditions of the enrichment culture caused a change in the microbial community com-position of the inoculated activated sludge. Dominant DGGE bands in the enrichment culture sample were affiliated with the classes
Journal of Environmental Sciences-china | 2015
Young-Rip Han; Young-Ik Choi
【This objectives of research are to figure out combustion characteristics with increasing temperature with petrochemical sludge by adding wasted organic matters which are waste electric wire, anthracite coal and sawdust, and to exam heating value and ignition temperature for using refused derived fuels(RDFs). After analyzing TGA/DTG, petrochemical sludge shows a rapid weight reduction by vaporing of inner moisture after
Journal of Environmental Sciences-china | 2015
Jin-Hee Jung; Young-Nae Yoon; Seulkee Lee; Young-Rip Han; Seung-Chul Lee; Young-Ik Choi
170^{\circ}C
Journal of Environmental Sciences-china | 2015
Young-Rip Han; Young-Ik Choi
. Gross weight reduction rate, ignition temperature and combustion rates represent 68.6%,
Journal of Environmental Sciences-china | 2015
Jin-Hee Jung; Seung-Chul Lee; Seulkee Lee; Young-Rip Han; Young-Nea Youn; Young-Ik Choi
221.9^{\circ}C
Journal of Environmental Sciences-china | 2014
Hyeng-Sik Son; Chul-Woo Jung; Young-Ik Choi; Gun Lee; Hee-Jong Son
and 54.1%, respectively. In order to assess the validity of the RDFs, the petrochemical sludge by adding wasted organic matters which are waste electric wire, anthracite coal and waste sawdust. The materials are mixed with 7:3(petrochemical sludge : organic matters)(wt%), and it analyzes after below 10% of moisture content. The ignition temperatures and combustion rates of the waste electric wire, anthracite coal and waste sawdust are
Journal of Environmental Sciences-china | 2014
Hee-Jong Son; Do-Hwan Kim; Young-Rip Han; Young-Ik Choi
410.6^{\circ}C