• Journal of Korean Society of Water and Wastewater
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• v.17 no.4
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• pp.567-573
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• 2003

The pretreatment process was carried out to solubilize the sewage sludge for enhancing its biodegradability using alkaline treatment, ultrasonic treatment(15kHz), ozone treatment and different combination of these three methods: alkaline followed by ultrasonic as well as ozone, and ultrasonic followed by alkaline. The solubilization efficiency was evaluated based on the SCOD/TCOD ratio and VSS/TS ratio. In results, the proper condition of alkaline treatment was shown as 30meq/l of NaOH, pH 12 and 3hours of reaction time. Solubilization efficiency increased to 17% from initial 2% based on SCOD/TCOD ratio under this condition. In ultrasonic treatment, the higher ultrasonic power, the longer treatment time and the lower sludge volume resulted in higher solubilization respectively. There was a rapid increase in solubilization efficiency after 20 minute, then it was measured as 32% of SCOD/TCOD ratio in 1 hour at a ultrasonic power of 1,300W with 1/sludge. Solubilization efficiencies in combined treatment using alkaline and ultrasonic were 47-53% higher than single treatment at a sonicated time of 1 hour. Ozone treatment followed by alkaline treatment also represented the enhanced solubilization compared to ozone treatment. Therefore, ultrasonic or ozone treatment assisted by alkaline could achieve the short treatment time as well as high solubilizetion efficiency.

• Journal of environmental and Sanitary engineering
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• v.11 no.2
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• pp.59-63
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• 1996

To treat certain wastewater that has alcohol and phenol, we performed the ozone electrolysis by using the titanium electrode. In this experiment, we examined decomposition voltage of organics, time for electrolysis, and removal efficiency of organics. In addition we compared the ozone oxidation electrolysis. The followings are results; 1. When it comes to the alcohol treatment in wastewater, ozone electrolysis showed higher removal efficiency than ozone oxidation or electrolysis. 2. After comparing the decomposition rate of methylalcohol, ethylalcohol, and prophylalcohol in ozone electrolysis, we knew the fact that increasing carbon number made the decomposition rate slow. 3. According to the treatment of alcohol by ozone electrolysis, decomposition voltage was 50V, time for electrolysis was three hours, and treatment acidity was neutral (pH 6.5 - 8.1). 4. Ozone electrolysis was effective to the phenol treatment. When we treated phenol by using ozone electrolysis for three hours, TOC treatment efficiency was 95%. However, ozone oxidation just showed 45% treatment efficiency.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.4
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• pp.369-376
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• 2010

The purpose of this study is to reprocess Waste-LCD(Liquid Crystal Display), to widely increase specific surface-area by foaming agent in the process of reprocessing and to use as a substrate of water treatment which is increased the ability of biological treatment, as well as to control non-point source pollutants produced by surface run off during rainfall with using this substrate, and to improve water quality of public watershed as developing substrate for water treatment to be able to purify second treated water which is exhausted at the wastewater treatment plant. The average removal efficiency of Waste-LCD that using the foaming technology was SS 71.2%, BOD 55.7%, COD 58.4%, T-N 29.5% and T-P was 50.3%. Almost Media, early stage showed low removal efficiency of SS and BOD. However, it became high when the microorganism adhered the Media. The variation of SS removal efficiency was high by inflow concentration of SS. The reason for the Media 4 showed high SS removal efficiency is that it has wide specific surface-area, and also it has a pore. All in all, it shows floating matter treatment ability not only inside but it also works outside of the substrate.

• Journal of Korean Society on Water Environment
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• v.25 no.2
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• pp.268-280
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• 2009

Oncheon basin which are located in Busan is divided into 43 basin on the basis of main pipe, constructed with Storm Water Management Model (SWMM). Occurrence situation for Outflow and pollutant loads by long-term continuous rainfall is examined for treatment district and river analysis point of Oncheon basin and a reduction vs effectiveness table for effective CSOs managements is made for each of treatment districts according to each of managements. In case that treatment equipment is located at the discharge point of CSO, treatment efficiency is analysed. It is supposed that treatment equipment have an efficiency on the basis of a concentration and runoff discharge over a critical flow is discharged with it untreated and treating runoff discharge with treatment equipment at each of runoff discharge points and treating it gathered at sewage treatment plant (STP) through trunk sewer is compared for a relative treatment efficiency.

• Environmental Engineering Research
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• v.25 no.4
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• pp.588-596
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• 2020

This study was carried out to increase the treatment efficiency through the improvement of the conventional biological process, and to propose the optimal treatment direction. The optimal treatment conditions were derived based on the results of the spike damage tests in each single process. The removal efficiency of micropharmaceuticals was further increased when an ozone treatment process was added to the biological process compared to the single process. The soil and activated carbon adsorption process was introduced in the post-treatment to remove the micropharmaceutical residues, and the removal efficiency of the pharmaceduticals in the final effluent was more than 85% in spike damage experiment. In particular, the continuous process of biological treatment-ozone-adsorption could ensure the stable treatment of micropharmaceuticals, which had not been efficiently removed in the single process, as it showed more than 80% removal efficiency. Therefore, it is expected that the addition of the ozone oxidation and activated carbon adsorption process to the existing sewage treatment facilities can contribute to the efficient removal of micropharmaceuticals.

• Journal of Wetlands Research
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• v.18 no.3
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• pp.267-274
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• 2016

Sewerage supply in rural community is the important for water quality protection of water system such as river, lake and wetland. And characteristic of small scale wastewater system that have wide range of inflow and concentration in sewage should be considered for stable operation of small scale wastewater treatment plant. In this research, characteristics of flow ratio (flow / designed flow), effect on treatment efficiency of small scale wastewater treatment plant and assessment of optimal flow ratio were conducted through analysis on operation result of 18 small scale wastewater treatment plant in Bong-hwa gun. As a result, flow ratio shows the higher value during summer. However pollutants concentration in sewage was shown the higher concentration during autumn and winter. Treatment of small scale wastewater treatment plant is increased when flow ratio increased, and nutrient treatment efficiency is more sensitive to change of flow ratio than organic compound and suspended solids. According to this research result, it need to be maintained flow ratio 0.8 over value for stable treatment efficiency of small scale wastewater treatment plant.

• Journal of Power System Engineering
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• v.12 no.3
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• pp.55-59
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• 2008

In this paper, we have investigated on collection efficiency of fine particle of glass fiber-filter bag according to the surface treatment. The solution consisted of polytetrafluoroethylene(teflon), graphite powder, silicon resin and water was used as a basic surface treatment agent. Tensile strength of glass filter-bag increased with up to 3hrs and then decreased with surface treatment time. Tensile strength and initial modulus of the glass fiber-filter bag treated by iodine after basic surface treatment for 3hrs were lower than those of basic surface treatment for 3hrs, however collection efficiency and fracture strain were higher than those of basic surface treatment for 3hrs. Glass fiber-filter bag with lower initial modulus and more strain will be extend the durable period and the one treated by iodine after basic surface treatment 3or 3hrs is expected high collection efficiency of fine particle. This method makes it possible to manufacture glass fiber-filter bag of the optimum condition.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.4
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• pp.297-301
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• 2017

Wastewater treatment using ferrate (VI) solution is becoming a promising technology for several years, because it is high efficient and harmless technology. In this study, the ferrate (VI) solution was tested to treatment of desulfurization wastewater. The effluent from desulfurization wastewater treatment process of power plant was used as raw water, and the COD and T-N removal efficiency of ferrate(VI) solution were investigated. In the test, as the injection rate increased from 0.1 to 1.0%, the removal efficiency of COD also slightly increased, about 80% of COD were removed in 1.0% of injection rate. In the case of T-N, about 50% of T-N was removed in the condition of 1.0% of injection rate. The removal efficiency of COD and T-N also affected by reaction time, maximum removal efficiency was shown in 30 min of treatment. From these results, the wastewater treatment with ferrate(VI) solution can be great solutions for treatment of non-biodegradable pollutants in wastewater, especially for the 3rd treatment of wastewater.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.12
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• pp.1143-1147
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• 2005

In this study, we report an improved efficiency of Organic light emitting diodes(OLEDs), using $UV/O_3$ treated anode and different cathode. We investigated the efficiency of OLEDs by $UV/O_3$ treatment of ITO surface. We Performed $UV/O_3$ treatment and found that $UV/O_3$ treatment enhanced the performance of OLEDs. The fundamental structure of the OLEDs was ITO $anode/{\alpha}-NPD/Alq_3/Al$ or Li:Al cathode. The Li:Al can improve the OLEDs efficiency dramatically in cathode because it has lower work function than Al. Current-voltage, Luminance-voltage characteristics and luminance efficiency were measured at room temperature.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.4
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• pp.311-319
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• 2019

The purpose of this study was to analyze water treatment characteristics, including the efficiency of removing algae from water purification plants, by installing a demonstration facility for decontamination of algae, including natural algae remover injection equipment, in the water purification plant. Jar-test showed that the optimum injection of natural decontaminant was 20 mg/L. Of the water contaminant treatment efficiency of the intake and water purification plants, Chl-a averaged 74.0% elimination efficiency from $5.0mg/m^3$ to $1.3mg/m^3$ and the maximum treatment efficiency was 91.5% removal efficiency when the inflow concentration of Chl-a was $11.8mg/m^3$. In addition, 51.2% and 47.1% of the taste and odor indicator items, geosmin and 2-MIB, resulted from the overgrowth and decaying of algae, respectively, to identify toxic substances and odor reduction effects. In addition, elimination efficiencies of SS and Turbidity materials were higher than 70.0%. In the injection of natural algae remover, no effects such as sudden changes in water quality due to secondary reactions were found, and appropriate levels were maintained under water treatment conditions.