• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.669-678
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• 2014

The amount of waste water generated from the domestic sources is consistently increasing in proportion to economic growth, and the conventional activated sludge process is widely being used for general waste water treatment. But the ministry of environment becomes stringthent treatment standards of N and P (less than 20mg/L of N, 2mg/L of P) to prevent the eutrophication of lake water, and therefore highly advanced treatment technology is required not only in the existing treatment plants where the activated sludge process is being used, but also in newly constructed treatment plants for the treatment of N and P. This study is aimed at highly operating the engineering technology method was developed by domestic to eliminate N and P at the same time. Experiments were conducted in the treatment plant located in Yong In city. The bioreactor was started from the principal equipment for the elimination of N and P and the elimination of organic compounds. It consists of an internal recycle piping from the end of the aerobic tank to the anoxic tank and external recycle piping from the final settling basin to the denitrification tank. By experiment of 4 types separate inflow of waste water to the denitrification tank and the anaerobic tank, and changes in staying time at the anoxic tank and the aerobic tank, the elimination of organic compounds in each type and the relationship in the efficiency between the elimination of N and P were researched.

• Environmental Engineering Research
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• v.11 no.1
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• pp.45-53
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• 2006

Conventional coagulation is still the main treatment process for algae removal in water treatment. The coagulation efficiency can be significantly improved by the preoxidation of algae-containing water. Jar test was conducted to determine the optimal condition for the removal of diatoms, especially Cyclotella sp. by preoxidation and the subsequent coagulation. The effects of various concentration of PAC (Polyaluminum chloride) on coagulation with and without preoxidation using chlorine or potassium permanganate at different pHs (7.7 and 9.0) were evaluated. At pH 7.7, preoxidation with 2ppm $Cl_2$ followed by coagulation with 7.5 ppm PAC coagulant could reduce Cyclotella sp. concentration by 86%. At pH 9.0, preoxidation with 1 mg $KMnO_4/L$ followed by coagulation with 12.5 ppm PAC coagulant reduced Cyclotella sp. concentration by 85%. Non-linear regression was applied to determine the optimal condition. At pH 7.7 and 9.0, R was over 0.9, respectively. The pH of algal blooming water is over 9.0. Algae (diatom; Cyelotella sp.) can be controlled in the following ways: preoxidation with 1 mg $KMnO_4/L$ followed by coagulation with 12.5 ppm PAC coagulant can remove 80% algae from water. If water pH is adjusted to 7.7, it was expected that less amount of coagulant (7.5 or 10 mg PAC /L) after preoxidation ($Cl_2$ 2 ppm or $KMnO_4$ 0.33, 1 ppm) would be needed to achieve similar level of algae removal. The oxidation with 0.33ppm $KMnO_4$ followed by coagulation with 7.5 ppm PAC coagulant was preferable due to cost-effectiveness of treatment condition and color problem after treatment.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.5
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• pp.541-548
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• 2014

The pickling brine generated from the salting process of kimchi production is difficult to treat biologically due to very high content of salt. When pickling brine is treated and discharged, it cannot satisfy the criteria for effluent water quality in clean areas, while resources such as the salt to be recycled and the industrial water are wasted. However, sterilization by ozone, UV and photocatalyst is expensive installation costs and operating costs when considering the small kimchi manufacturers. Therefore there is a need to develop economical process. The study was conducted on the sterilization efficiency of the pickling brine using electrochemical processing. The electrochemical treatment of organic matters has advantages over conventional methods such as active carbon absorption process, chemical oxidation, and biological treatment because the response speed is faster and it does not require expensive, harmful oxidizing agents. This study were performed to examine the possibility of electrochemical treatment for the efficient processing of pickling brine and evaluated the performance of residual chlorine for the microbial sterilization.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.6
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• pp.481-490
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• 2017

Water and wastewater treatment has always been a challenging task due to the continuous increase in amount and the change in characteristics of the poorly biodegradable and highly colored organic matters, as well as harmful micro-organisms. Advanced techniques are therefore required to successfully remove these pollutants from water before reuse or discharge to receiving water bodies. Application of ozone, which is a powerful oxidant and disinfectant, alone or as part of advanced oxidation process depends on the complex kinetic reactions and the mass transfer of ozone involved. Micro- and nano bubbling considerably improves gas dissolution compared to conventional bubbles and hence mass transfer. It can also intensify generation of hydroxyl radical due to collapse of the bubbles, which in turn facilitates oxidation reaction under both alkaline as well as acidic conditions. This review gives the overview of application of micro- and nano bubble ozonation for purification of water and wastewater. The drawbacks of previously considered techniques and the application of the hydrodynamic ozonation to synthetic aqueous solutions and various industrial wastewaters are systematically reviewed.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.2
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• pp.113-118
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• 2014

So many nationwide drinking water treatment plants are under much difficulties by new reinforced discharged effluent standards. Generally, the sludge at thickener should be retended for a long time during usual days. Sometime, the soluble manganese and chloroform may be formed under the anaerobic condition in the sludge thickener when the sludge retention time is longer with low turbidity. This phenomenon results in difficulties to keep regulatory level of the discharged effluent. It was necessary to improve the operation conditions and process itself in order to meet water quality standard recently reinforced. For an effort to overcome the problems, a sludge aeration was successfully implemented into the thickening process. Sludge aeration prevent particle oxidated Manganese eluting soluble de-oxidated Manganese, excrete formated Chloroform from effluent to air, and improve sludge settling through homogenized sludge particle. We aerated sludge at the conventional water treatment plant, measured Manganese and Chloroform of clarified water at upper sludge, and solid-fluid interface height of sludge in mass cylinder. As a result, contaminant's concentrations of the final effluent was much decreased : 41% of manganese, approximately 62% of chloroform and 35% of sludge volume, compared with non-aeration sludge.

• Journal of Fashion Business
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• v.15 no.5
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• pp.43-54
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• 2011

Digital Textile Printing(DTP) is appropriate for quick response system(QRS) and is closely connected with high value added fashion industry. Fashion products of high price are mainly silk and cotton. For high quality DTP products, it is important to optimize the parameters of media, pre and after-treatment, ink, printer, etc. DTP for these two fiber materials is also accompanied certainly with steaming as after-treatment process for coloration. Role of steam is like water in exhaustion dyeing. Steam can diffuse dye or ink in printing paste to fiber. Quality of DTP products depend on after-treatment processes such as steaming, washing, drying. Current production amount of DTP is smaller than one of conventional textile printing. However conventional after-treatment system has been using so far. This is mismatched with DTP in terms of process efficiency, spot work of small lot, quality control. In this study, continuous after-treatment system has been suitably designed for DTP that washing and drying are available after steaming. So, It is possible to improve efficiency of DTP process. Especially, the effects of after-treatment process, such as temperature of heat drum, steaming time on printability, color difference, color fastness were examined. Two types of samples(cotton knit and silk fabrics) were used. The results were obtained as follows : First, there is no a wide difference between the K/S values of cotton and silk treated with continuous after-treatment system and those of sample treated with conventional printing after-treatment method. So it is more effective to use the continuous after-treatment system than conventional printing after-treatment system in case of the daily throughput of 1,000 yards below. Second, after continuous after-treatment for DTP, K/S values were increased and lightness($L^*$) values were decreased. ${\Delta}E$ values were below 2.3. Third, DTP samples treated with continuous after-treatment system were tested for fastness(washing, light, rubbing). Grades of fastness(washing, light, rubbing) were above 3 grade.

• Journal of Environmental Health Sciences
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• v.31 no.3
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• pp.192-198
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• 2005

The occurrence of toxic cyanobacterial blooms has been reported worldwide and poses a threat to human health through drinking water exposure. The toxins they produce are highly water soluble and can leach into the water body. To eliminate any risk of drinking water exposure, removal of these toxins is essential before the water is consumed. Conventional water treatment techniques such as chlorination, if managed well, can be effectively used to remove some of these toxins, however, saxitoxin and its derivatives pose a problem. Little toxicological data are available to evaluate the real threat of these toxins.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.1
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• pp.87-98
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• 1994

Sludge minimization in an water treatment plant can be achieved by optimizing a main water treatment process as well as by enhancing a thickening and a dewatering facilities. In this study, dewatering and drying techniques for reducing the quantity of the water sludge generated from the conventional water treatment plant in the local states were investigated by reducing its water content. Not only the types and dosages of polymers but also the mixing intensity of the mixtures of a concentrated sludge and polymers on the different pH were evaluated for the optimum dewatering conditions of the water sludge. Weight reduction of the water sludge was also tested at a given temperature range. The dewatering efficiency of the water sludge was not affected by the types of polymer but by mixing intensity(GT value) in this study. pH effect on dewaterbility of the water sludge took a major role at the neutral pH range. The optimal polymer dose was 1.5 mg-polymer/g-TSS(about 40mg/L as polymer). Dewaterability was enhanced at a lower mixing intensity(GTbelow 10,000 sec-1). Free water in the void of sludge cake was dried around $100^{\circ}C$, chemical bound water was evaporated around $320^{\circ}C$, and organic material was burned out at the range of 300 to $600^{\circ}C$. Ignition losses of the water sludge were varied 15 to 40 % as the raw water quality. The ignition loss due to the chemical bound water was 10-20% and the loss due to the organic material was 4-20% of the total ignition loss.

• Advances in materials Research
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• v.6 no.4
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• pp.329-341
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• 2017

The challenge of replacing conventional plastics with biodegradable composite materials has attracted much attention in product design, particularly in the tensile-related areas of application. In this study, fibres extracted from oil palm empty fruit bunch (EFB) were treated and utilized in reinforcing polyester matrix by hand lay-up technique. The effect of fibre loading and combined influence of alkali and silane treatments on porosity and water absorption parameters, and its correlation with the tensile behaviour of composites was analyzed. The results showed that tensile strength decreased whilst modulus of elasticity, water absorption and porosity parameters increased with increasing fibre loading. The composites of treated oil palm EFB fibre exhibited improved values of 2.47 MPa to 3.78 MPa for tensile strength; 1.75 MPa to 2.04 MPa for modulus of elasticity; 3.43% to 1.68% for porosity and 3.51% to 3.12% for water absorption at respective 10 wt.% fibre loadings. A correlation between porosity and water absorption with tensile behavior of composites of oil palm EFB fibre and positive effect of fibre treatment was established, which clearly demonstrate a connection between processing and physical properties with tensile behavior of fibre composites. Accordingly, a further exploitation of economic significance of oil palm EFB fibres composites in areas of low-to-medium tensile strength application is inferred.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.255-261
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• 2004

Experiments using ozone are presented for the water purification and wine quality improvement. Advanced oxidation process results reveal water treatment by both ozone and UV radiation increases quality of the takju prepared using a Korean conventional nuruk than with ozone-treatment or convectional method only. Water quality was enhanced by ozone treatment, resulting in 85% reduction of hardness, and 30% increase in total glucose produced due to increased conductivity and biodegradability of water. Although initially decreased slightly due to oxidation of takju, higher than expected ethanol production was observed, with ozone plus UV treatment resulting in 20% higher production compared with other methods.