• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.436-442
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• 2017

This study was conducted to develop a wastewater treatment system to remove organic matter, nitrate nitrogen, and phosphate ion in synthetic wastewater. COD was removed almost 100% by the oxidation reaction of HClO and nitrate nitrogen was reduced to ammonia by electrolysis treatment, but ammonia was reoxidized into nitrate nitrogen by HClO treatment. Ammonia was removed almost 100% by heating evaporation and no ammonia was reoxidized into nitrate by HClO treatment. Phosphate ion could be removed by precipitation treatment by forming metal complex according to pH. Through electrolysis treatment and HClO treatment, removal efficiencies of COD 99.5%, nitrogen 97.3% and phosphorus 91.5% were obtained.

• Environmental Engineering Research
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• v.13 no.2
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• pp.69-72
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• 2008

The movement of sediments in the stream crossing a large industrial complex to the mouth of Masan Bay was monitored for eight years. Sediment samples were seasonally collected in the period of $1992{\sim}1997$ and $2001{\sim}2002$. The heavy metal content of sediment was found to be higher at dry season with the peak on February and significantly decreased at rainy season. Metals content in stream sediments were rapidly decreased by large precipitation events in rainy season because the contaminants in the upstream sediments were transported to the dredged area of Masan Bay where is a typical enclosed bay in Korea. The increasing and decreasing tendency of heavy metals in sediment was repeatedly observed for six consecutive years. The heavy metals assessment of stream sediment provide us the information about the pollutant source, transport pattern and control strategy along the industrial complex. It was strongly suggested that the transportable stream sediments of an industrial area should be controlled as one of the important strategies to restore and manage the enclosed bay. Combined wastewaters have been collected and treated in a publicly owned treatment works (POTW) after industrial wastewater treatment at each location of industries since 1994. A field study was conducted to investigate the pollutant removal efficiency and performance of contact oxidation system installed and operated in two locations in the stream. The stream sediment quality was improved since then, and as a consequence the habitat of the estuary has been restored.

• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.467-472
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• 2012

In this study, water quality and acute toxicity using Daphnia magna were analyzed to investigate the eco-toxicological substances identified as statistical analysis and propose a management plan for the effluent of Banwol industrial complex, Ansan, Gyeonggi-do. Cu, Zn, F, Mn concentrations in the effluent far exceeded the US standards to protect the aquatic ecosystem and eco-toxicity values were 5 ~ 22 TU. However, concentrations of heavy metals significantly decreased after Ansan public wastewater treatment plant operating a biological treatment and toxicity values were 0 TU. Zn, Cr, F and Cu in the effluent showed very strong and strong positive correlations with eco-toxicity values, respectively. Regression analysis resulted in an equation between toxicity and Zn, TU = $4.884{\times}Zn$ (mg/L) -0.391 showing Zn concentration should be managed less than 0.285 mg/L to keep the eco-toxicity (TU) less than 1.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.2
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• pp.40-49
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• 1997

From water management point of view, the industrialization that we have achieved in the last decades brought out two major changes: water shortage and water quality deterioration. They are getting the big obstacles we must overcome to continuously pursue industrialization for further development in the next century. Many plans using dams and advanced treatment methods have been developed for control of quantity and quality, respectively. In this paper, an alternative is conceptually reviewed which is much different from the plans in regard that the alternative looks at system itself. It is based on an interceptor system coupling with a concept of zero-discharge. This system allows no discharge of wastewaters from point-sources to waterbodies which are very sensitive in terms of water quality. In addition reuse of treated effluents is emphasized to a maximum extent. The application of the system to the Nak-Dong river basin indicated that an interceptor system will need from the middle reaches of the basin where industrialization gets heavier. Since wastewaters are not directly discharged to the river, water quality of the down stream will improve. Treated effluents will be able to be reused at a number of industrial complex which currently get water from the Nak-Dong river. This reuse will help alleviate water shortage. The biggest problem anticipated is cost for building and operating such system. A cost-sharing plan among the beneficiaries is considered. Further research is suggested focusing on detailed engineering and technical matters for potential implementation.

• Clean Technology
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• v.28 no.1
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• pp.63-78
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• 2022

Electronics industrial wastewater treatment facilities release organic wastewaters containing high concentrations of organic pollutants and more than 20 toxic non-biodegradable pollutants. One of the major challenges of the fourth industrial revolution era for the electronics industry is how to treat electronics industrial wastewater efficiently. Therefore, it is necessary to develop an electronics industrial wastewater modeling technique that can evaluate the removal efficiency of organic pollutants, such as chemical oxygen demand (COD), total nitrogen (TN), total phosphorous (TP), and tetramethylammonium hydroxide (TMAH), by digital twinning an electronics industrial organic wastewater treatment facility in a cyber physical system (CPS). In this study, an electronics industrial wastewater activated sludge model (e-ASM) was developed based on the theoretical reaction rates for the removal mechanisms of electronics industrial wastewater considering the growth and decay of micro-organisms. The developed e-ASM can model complex biological removal mechanisms, such as the inhibition of nitrification micro-organisms by non-biodegradable organic pollutants including TMAH, as well as the oxidation, nitrification, and denitrification processes. The proposed e-ASM can be implemented as a Water Digital Twin for real electronics industrial wastewater treatment systems and be utilized for process modeling, effluent quality prediction, process selection, and design efficiency across varying influent characteristics on a CPS.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2333-2335
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• 2000

The main motivation of this research is to develop an intelligent control strategy for Activated Sludge Process(ASP). ASP is a complex and nonlinear dynamic system because of the characteristic of a wastewater, the change of an influent flow rate, weather conditions, and etc. The mathematical model of ASP also includes uncertainties which are ignored or not considered by process engineer or controller designer. The ASP is generally controlled by a PID controller that consists of fixed proportional, integral, and derivative gain values. The PID gains can be adjusted by the expert in the ASP. The ASP model based on Matlab$^{(R)}$5.3/Simulink$^{(R)}$3.0 is developed in this paper. Various control methods are applied to the ASP model and the control results are disscussed. Three control methods are designed and tested: conventional PID controller, fuzzy logic control approach to modify setpoints, and fuzzy-PID control method.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.1 no.1
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• pp.56-61
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• 2001

Activated sludge processes are broadly used in the biological wastewater treatment processes. The activated sludge processes are complex systems because of the many factors such as the variation of influent flowrate and ingredients, the complexity of biological reactions, and the various operation conditions. The main motivation o this research is to develop an intelligent control strategy for activated sludge process (ASP). ASP is a complex and nonlinear dynamic system owing to the characteristic of wastewater, the change in influent flowrate, weather conditions, and so on. The mathematical model of ASP also includes the uncertainty which is a ignored or unconsidered factor from process designers. The ASP model based on Matlabⓡ/Simulinkⓡ is developed in this paper. And the model performance is examined by IWA (International Water Association) and COST (European Cooperation in the filed of Scientific and Technical Research) data. The model tests derive steady-state results of 14 days. In this paper, fuzzy logic control approach is applied to handle DO concentrations. The fuzzy logic controller includes two inputs and one output to adjust air flowrate. The objective function for the optimization, in the implemented evolutionary strategy, is formed with focusing on improving the effluent quality and reducing the operating cost.

• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.2
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• pp.96-105
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• 1997

In this paper, A new design method of fuzzy modeling is presented for the model identification of nonlinear complex systems. The proposed FPNN(Fuzzy Polynomial Neural Network) modeling implements system structure and parameter identification using GMDH(Group Method of Data Handling) method and linguistic fuzzy implication rules from input and output data of processes. In order to identify premise structure and parameter of fuzzy implication rules, GMDH method and regression polynomial fuzzy reasoning method are used and the least square method is utilized for the identification of optimum consequence parameters. Time series data for gas furnace and those for wastewater treatment process are used for the purpose of evaluating the performance of the proposed FPNN modeling. The results show that the proposed method can produce the fuzzy model with higher accuracy than other works achieved previously.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.387-392
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• 2006

There have been several problems in treating shipboard sewage due to special environmental conditions of ship, such as limited space, rolling and pitching, change of temperature and so on. It was suggested that Sequence Batch Reactor (SBR) might be suitable process for overcome these problems in terms of small size, high capacity of treating wastewater and full automation. In this study a SBR process was employed for biological treatment of organic wastes in the shipboard sewage. This process was able to remove nitrogen and phosphorus as well as organic matter efficiently. More than 95% of chemical oxygen demand(COD) were removed. In addition, about 97% of total nitrogen (T-N) was reduced. The total phosphorus(T-P) reduction averaged 93%. A disturbance operation caused by the treatment of Methylene Blue Active Substances(MBAS) was not observed.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.170-174
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• 1997

Constructed wetland system was studied to treat wastewater from industrial complex in rural area. Pilot plant at the Baeksuk Nongkong Danzi in Chunahn-City was used for field study. For the DO, the effluent concentration was higher than the influent concentration and it implies that natural reaeration supplies enough oxygen to the system. For the SS, the effluent concentration was consistently lower than the water quality standard even though the influent concentration varied significantly, which showed that SS was removed by the system effectively which is consist of soil and plants. For the BOD and COD, the average removal rate of them were 56% and 43%, respectively, therefore, the effluent concentration could not meet water quality standards when influent concentration was high. The removal rate of BOD and COD can be improved by supplemental treatment in addition to this system if necessary. For the T-N and T-P, the influent concentration of them were lower than the water quality standards than no further treatment was needed. Overall, the result showed that constructed wetland system is a feasible alternative for the treatment of wastewater from industrial complex in rural area. For actual application of this system, further study on design factors including loading rate, removal mechanism, and temperature effects is required to meet water quality standard consistently. Compared to existing systems, this system is quite competitive because it requires low capital cost, almost no energy and maintenance, and therefore, very cost effective.