• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.909-918
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• 2009

As a part of dissolved organic matter, dissolved organic carbon (DOC) or biodegradable DOC (BDOC) fraction in particular is one of important issues in water treatment. Due to role as a nutrient source for bacteria, BDOC, therefore, may cause regrowth problems in water distribution system. The main objectives of this study were to investigate the possibility to minimize the concentration of BDOC in advance water treatment process. DOC in water is fractionized into four fractions such as AnBDOC (adsorbable and non-biodegradable DOC) which possesses adsorption properties but no biodegradation ability; nABDOC (biodegradable and non-adsorbable DOC) which has biodegradation properties but no adsorption ability; ABDOC (adsorbable and biodegradable DOC) which has adsorption properties and biodegradable characteristic; and non-removal DOC (nAnBDOC) which do not have either adsorbability or biodegradability. BAC process was effective for adsorbable DOC (AnBDOC+ABDOC) removal. However, in some cases, the removal ratio of adsorbable DOC was not sufficient. BDOC removal rate is very low or irremovable. Thus, for the control of residual DOC, it is necessary to change the operation condition by BAC process. From the analysis results of DOC fractions, water treatment processes appeared to be effective because it could grasp a remarkable amount of biodegradable, adsorbable and non-removal DOC. The concentration of AOX in non-prechlorination process was reduced from 7.1 ${\mu}g$/L to 0.51 ${\mu}g$/L in BAC process followed by ozonation.

• Korean Journal of Environmental Agriculture
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• v.21 no.3
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• pp.189-196
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• 2002

This study was carried out to evaluate the pollutant removal efficiencies of the advanced drinking water treatment using ozonation process. For raw water, Nakdong River was used. By conducting continuous ozonation experiments, the following results were obtained. Efficiency of water treatment was enhanced with increase in ozone dosage. When ozone dosage of 3 mg/L was used, preozonation ot raw water reduced TDOC, ADOC, A &BDOC and NRDOC as much as 0.6 mg/L, 0.2 mg/L, 0.1 mg/L and 1.0 mg/L, respectively. On the other hand, content of BDOC increased at the level of 0.8 mg/L. Ratio of UV254 absorbance to DOC content by the preozonation with 1, 3 and 5 mg/L dosage were 0.048, 0.044 and 0.037, respectively. In case of postozonation, it were 0.018, 0.015 and 0.012, respectively. When the ratios of consumpted ozone content to 1 mg of initial DOC were 1.5 and 2.3 in preozonation and postozonation treatment, respectively, the highest DOC removal rates of 25% and 32% were obtained by the continuous ozonation.

• Korean Journal of Occupational Therapy
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• v.26 no.4
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• pp.27-41
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• 2018

Objective : This study implemented occupation-based practice as a group program for children with neurodevelopmental disabilities, and investigated the quality of occupational performance, performance and satisfaction, and efficacy levels of the program. Methods : ADOC-S(Aid for Decision making in Occupation Choice-School) and COPM(Canadian Occupational Performance Measure) were used to establish common meaningful occupational goals for 10 children with neurodevelopmental disabilities. After occupational analysis of the 'subway use', the Performance Quality Rating Scale(PQRS) were used to evaluate the quality of occupational performance. Occupation-based interventions were implemented by participants individually performing meaningful occupations in the most natural and real-life environments as possible. The trial consisted of 1 session of pre-intervention assessments, 8 sessions of intervention, where a single session of 100 minutes is provided once a week. Post-intervention evaluation was conducted over one session. Results : The quality of occupational performance by PQRS was 38.10 higher than before intervention. The occupation-based intervention as a group program used the maintain and modify(compensation, adaptation) approaches and acquisition model. In the early stages of intervention (1 to 4 sessions), the occupational performance was greatly improved. The performance level of COPM increased by 5.80 and the satisfaction level was increased by 7.00. In addition, high scores were found in program satisfaction through parental interview. Conclusion : The results of implementing occupation-based interventions to children with neurodevelopmental disabilities showed increase in quality of occupational performance, performance, and satisfaction along with positive effects of satisfaction levels for the program.