• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.6
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• pp.757-764
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• 2002

Chlorination dosage in water treatment plant of field is determined by chlorination demand experiment through two or three hours after raw water was sampled in inflow. It is impossible to continuously control for real time because the sampled water is adapted chlorination dosage after water treatment process had been proceeded. Therefore in this study, we will design informal chlorination demand system, this designed system will be experimented as to water quality and accuracy of control in various conditions. Throughout these experimental results, we will revise the system and the revised system is enable to optimal control of chlorination dosage. Finally, we have developed chlorination demand system, which can automatically determination of chlorination dosage to be determined according to variety of raw water quality inflow in water treatment plant.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.807-812
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• 2000

Chlorination dosage in water treatment plant of field is determined by chlorination demand experiment through two or three hours after raw water was sampled in inflow. It is impossible to continuously control fer real time because sampled water is adapted chlorination dosage after water treatment process had been proceeded. Therefore in this study, we will design informal chlorination demand system this designed system will be experimented as to water quality and accuracy of control in various conditions. Throughout these. experimental results, we will revise the system and revised system is enable to optimal control of chlorination dosage. Finally, We have developed chlorination demand system, which can automatically determination of chlorination dosage to be determined according to variety of raw water quality inflow in water treatment plant.

• Journal of Korean Society on Water Environment
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• v.21 no.2
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• pp.176-183
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• 2005

Chlorination of wastewater is recently practiced in Korea. While many researchers have studied the kinetics of aqueous chlorine(HOCl) with nitrogeneous compounds and other organic/inorganic contaminants in drinking water, the researches of wastewater chlorination are relatively few. The purpose of this study was to investigate the chlorine decay kinetics and parameters on wastewater chlorination. Chlorine decay rate increased with increasing initial chlorine concentration. The parameters affecting chlorine decay rate were different in each wastewater treatment plant. One of the most important parameters affecting chlorine decay was initial chlorine concentration, and other parameters such as $NH_3-N$, total coliform, $UV_{254}$ and Fe were also affected. The decay ratio of chlorine was decreased with increasing initial chlorine concentration, and the disinfection efficiency showed good correlation with the decay ratio.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.2
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• pp.65-75
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• 1997

Removal characteristics of volatile organic carbons(VOCs) by ozone oxidation and other processes in the raw water of the 1st Nakdong water treatment plant were investigated. Dichrolomethane, toluene and other 7 compounds were detected in the raw water. With regard to detected 4 compounds in finally treated water, it was found that VOCs could not be removed effectively by traditional water treatment process. Benzene, 1,2-dichlorobenzne were not detected in the raw water but they were detected in the process of treatment. The compound of highest detection frequency was dichloromethane. When the raw water was controlled at pH 7, temperature $20^{\circ}C$, 5 minutes as contact time, 10 minutes as reaction time, the removal rate of THMFP, $KMnO_4$ demand, TOC, $UV_{254nm}$ and $NH_3-N$ were 46.4%, 22%, 19.6%, 31% and 8%, respectively. From estimating the finally treated water qualities in 7 kinds of treatment processes, P-6 process(raw water-chlorination-coagulation-ozonation) was most effective for organics removal and THMs control. Removal efficiencies for $KMnO_4$ demand and TOC by the process which combined preozonation with coagulation was twice better than only preozonation. $NH_3-N$ removal rate was shown as 10% by P-3 process(raw water-coagulation-ozonation), but 83% of $NH_3-N$ was removed by P-4 process(raw water-coagulation-chlorination). It was found that the chlorination is more effective than the ozonation for the NH3-N removal as commonly known.

• Advances in environmental research
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• v.4 no.3
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• pp.155-172
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• 2015

In this study, a complete set of recirculating cooling water system and the required instruments were built in a semi-industrial-scale and a 50 g/h ozone generation plant and a chlorine system were designed for cooling water treatment. Both chlorination and ozonation treatment methods were studied and the results were analyzed during two 45-days periods. The concentrations of ozone and chlorine in recirculating water were constant at 0.1 mg/lit and 0.6 mg/lit, respectively. In ozone treatment, by increasing the concentration cycle to 33%, the total water consumption decreased by 26% while 11.5% higher energy efficiency achieved thanks to a better elimination of bio-films. In case of Carbon Steel, the corrosion rate reached to 0.012 mm/yr and 0.025 mm/yr for the ozonation and chlorination processes, respectively. Furthermore, consumptions of the anti-corrosion and anti-sedimentation materials in the ozone cooling water treatment were reduced about 60% without using any oxidant and non-oxidant biocides. No significant changes in sediment load were seen in ozonation compared to chlorination. The Chemical Oxygen Demand of the blow-down in ozonation method decreased to one-sixth of that in the chlorination method. Moreover, the soluble iron and water turbidity in the ozonation method were reduced by 97.5% and 70%, respectively. Although no anaerobic bacteria were seen in the cooling water at the proper concentration range of ozone and chlorine, the aerobic bacteria in chlorine and ozone treatment methods were 900 and 200 CFU/ml, respectively. The results showed that the payback time for the ozone treatment is about 2.6 years.

• Journal of Environmental Health Sciences
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• v.29 no.1
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• pp.8-15
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• 2003

In this study, chlorine dose at water storage tank was predicted to meet the recommended guideline for free chlorine residual in drinking water distribution system, using EPANET which is a computer program that performs extended Period simulation of hydraulic and water quality behavior within pressurized pipe networks. The results may be summarized as follows. The decay of chlorine residual by season varied considerably in the following order; in summer ($25^{\circ}C$) > spring and fall (15$^{\circ}C$) > winter (5$^{\circ}C$). For re-chlorination at water storage tank by season, season-varying chlorine dose was required at its maximum of 1.00 mg/l in summer and minimum of 0.40 mg/l in winter as free chlorine residual. The decay of chlorine residual through out the networks increased with water age spent by a parcel of water in the network except for some points with low water demand. In conclusion, the season-varying chlorine dose as well as the monitoring of water quality parameters at the some points which showed high decay of chlorine residual may be necessary to deliver the safe drinking water.

• Resources Recycling
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• v.18 no.2
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• pp.16-29
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• 2009

This paper describes characteristics of pollutants in wastewater from the pulp and paper industry and biological technologies for the wastewater treatment. The wastewater from the pulp and paper industry contains high concentrations of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) and shows high toxicity and strong black-brown color. In particular, organic chlorinated compounds such as dioxins and furans may be formed by the chlorination of lignin in wood chips. Thus the pulp and paper industry is recently trending toward total chlorine-free (TCF) bleaching processes. All biological technologies for pulp and paper wastewater treatment are based on the contact between wastewater and bacteria, which feed on organic materials in the wastewater, thus they reduce BOD concentration in it. Both aerobic and anaerobic treatments were found to be effective for the wastewater treatment. Furthermore, advanced technologies such as fungal application and combined biological-filtration process have been also introduced to the wastewater treatment field. These technologies would be useful for water recycling to reduce water consumption throughout pulp and paper making process.