• Journal of Wetlands Research
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• v.21 no.4
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• pp.374-383
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• 2019

The Wangpo stream located in the Buyeo-gun was a small stream with both low water quality and quantity due to the cultivated land and settlement area through the stream. In order to restore ecosystem, the Sustainable Structured wetland Biotop system was applied to treat 1,500 to 7,000 ㎥/d amount of effluent water pumped from the Buyeo sewage treatment plant facility as well as inflowed from nonpoint pollution source of Wangpo stream. As a result of continuous monitoring for 2 years from 2016 to 2018 after completing restorative construction, the average BOD₅ as an index of organic pollution was 7.3 mg/L and the average effluent concentration became 2.1 mg/L, showing an improvement by 71.2%. The average inflow concentration of T-N was 7.953 mg/L and the average outflow concentration was 3.379 mg/L, showing 57.5% of improvement. The average inflow concentration of T-P was 0.177 mg/L and the average outflow concentration was 0.052 mg/L, showing about 70.7% improvement. The results of ecological monitoring after creating biotope by reuse of treated waste water and nonpoint pollution source of the Wangpo Stream are as follows. The plant taxa founded in water SSB(Sustainable Structured wetland Biotop) system of the Wangpo Stream was total 41 species in 21 families, showing a higher proportion of naturally introduced plant than that of artificially planted species. In case of other terrestrial animals, both amphibian and reptile group were confirmed as 3 species in 6 families, avian group was 25 species of 15 families, and mammal group observed 5 species in 5 families, respectively. All species have been created and enhanced through purified water inhabited in the SSB(Sustainable Structured wetland Biotop) system as a treatment wetland, eventually migrating to the Wangpo Stream.

• Journal of environmental and Sanitary engineering
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• v.14 no.1
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• pp.42-53
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• 1999

A study on the synthesis of zeolite from coal fly ash from power plant was carried out to reduce environmental problems and reuse industrial waste. The synthesized zeolite was proved to be Zeolite 4A type by means of the XRD and SEM analysis, and then the synthesized zeolite was used as an absorbent to remove the $NH_4^+$ ions in the wastewater and water. In the ion exchange of single $NH_4^+$ ions by the natural zeolite and the synthesized zeolite, the ion exchange reached equilibrium within 10 min. and 1hr, respectively. The amount of ion exchanged $NH_4^+$ to the unit weight of natural zeolite and zeolite 4A were 1.09 and 3.54 meq/g respectively, and the amount of $NH_4$ ion exchanged by the synthesized zeolite was higher than by the natural zeolite. The ion exchange kinetics fitted very well to the Feundlich and Langmuir isotherm. The effects of coexisting cations on the ion-exchange properties of zeolites were studied in order to apply them to water treatment. In the bisolute-system of the $NH_4^+-K^+$ and $NH_4^+-Na^+$ systems, the ion exchange capacity was smaller than the single $NH_4^+$ ion system. The effects of coexisting cations on the ion exchange system by the natural zeolite and the synthesized zeolite were found to be $K^+>Na^+$ and $Na^+>K^+>>Mg^{2+}>Ca^{2+}$, respectively.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.893-900
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• 2004

This paper is to define the method that develops the software In proper to application areas of Geographic Information Systems and design patterns according to functions and roles that implement the system for safety evaluation of the groundwater well based on an object oriented spatial model. In order to design the user interface of the groundwater well, this paper proposes the framework that should classify only requisite components adaptable to various application areas. By specifying De pattern appropriate to the application domain and designing the analysis pattern using the UML based on the object oriented methodology. this paper shah contribute to enhance the reuse of components that can develop and distribute a .large scale open system.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.4
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• pp.55-65
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• 2003

Pilot study was conducted to examine the effects of ponded-water depth and reclaimed wastewater irrigation on paddy rice culture. For the ponded-water depth effect, three treatments of shallow, traditional, and deep water depths were applied, and each treatment was triplicated. The irrigation water for the treatment pots was an effluent from constructed wetland system for sewage treatment, while the control pot was irrigated with tap water kept traditional ponded-water depth. Irrigation water quantity varied with ponded-water depth as expected and drainage water quantity also varied similarly, which implies that shallow irrigation might save irrigation water and also reduce environmental impacts on downstream water quality. Rice growth and production were not significantly affected by ponded-water depth within the experimental condition, instead there was an indication of increased production in shallow and deep ponded-water depths compared to the traditional practice. Raising drainage outlet to the adequate height in paddy dike might be beneficial to save water resources within the paddy field. There was no adverse effect observed in reclaimed wastewater irrigation on the rice production, and mean yield was even greater than the control pots with tap water irrigation although statistically not significant. Water-saving irrigation by shallow ponded-water depth, raising the outlet height in diked rice paddy fields, minimizing forced surface drainage by well-planned irrigation, and reclaimed wastewater irrigation are suggested to save water and protect water quality. However, deviation from traditional farming practices might affect rice growth in long term, and therefore, further investigations are recommended before full scale application.

• Membrane and Water Treatment
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• v.9 no.1
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• pp.17-21
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• 2018

A series of laboratory scale experiments were performed to investigate the feasibility of membrane separation technology for natural rubber (NR) wastewater treatment and reuse. Three types of spiral wound membranes were employed in the cross-flow experiments. The NR wastewater pretreated by sand filtration and cartridge filtration was forced to pass through the ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membranes successively. The UF retentate, which containing abundant proteins, can be used to produce fertilizer, while the NF retentate is rich in quebrachitol and can be used to extract quebrachitol. The permeate produced by the RO module was reused in the NR processing. Furthermore, about 0.1wt% quebrachitol was extracted from the NR wastewater. Besides, the effluent quality treated by the membrane processes was much better than that of the biological treatment. Especially for total dissolved solids (TDS) and total phosphorus (T-P), the removal efficiency improved 53.11% and 49.83% respectively. In addition, the removal efficiencies of biological oxygen demand (BOD) and chemical oxygen demand (COD) exceeded 99%. The total nitrogen (T-N) and ammonia nitrogen (NH4-N) had approximately similar removal efficiency (93%). It was also found that there was a significant decrease in the T-P concentration in the effluent, the T-P was reduced from 200 mg/L to 0.34 mg/L. Generally, it was considered to be a challenging problem to solve for the biological processes. In brief, highly resource utilization and zero discharge was obtained by membrane separation system in the NR wastewater treatment.

• Journal of environmental and Sanitary engineering
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• v.20 no.3 s.57
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• pp.36-43
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• 2005

Prior to the study of the sewage treatment methods, water quality for Gwangju sewage of fluent was investigated from January to December, 2004 for sewage water reuse. Monthly mean values of BOD, SS, turbidity, total phosphorus and color were 4.1 mg/L, 2.9 mg/L, 0.8 NTU, 1.3 mg/L, and 27 unit, respectively. Jar-test was performed to investigate the removal efficiency of pollutants under the coagulation conditions of fast mixing for 5 min, slow mixing for 15 min and precipitation for 1hr. Here, alum and polyaluminium chloride (PAC) were used as coagulants to reduce color, turbidity, total phosphorus (TP) and total organic carbon (TOC) in sewage effluents. The results showed that PAC gave better efficiency in removing turbidity and dissolved phosphorus than alum. It was also found from the relative molecular weight (RMW) distribution analysis that organic matter over 1,000 Dalton (Da) was easily removed by coagulation and subsequently MF treatment, while it was not effective for less than 500 Da. Based on tis result, Natural organic matter (NOM) with lower molecular weight (< 500 Da) may cause harmful disinfectant by-product (DBP) after chlorine treatment. Thus, activated carbon adsorption seems to be required for the complete removal of DBP in the hybrid system.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.150-152
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• 1998

Now the lack of water is serious problem all over the world because of the growth of population and expansion of industrial activities. So wastewater recycle and reuse is essential in many countries. One of the most popular wastewater treatment processes is conventional activated sludge system. In spite of significant degree of treatment rate the biological process has some operational difficulties and capital disadvantages. In conventional activated sludge process, sludge settling condition is getting worse in case of sludge bulking, it is common that overall process fails due to wash-out of biomass causing low concentration of MLSS in the aeration tank. Because of the absence of claifier the membrane bioreactor(MBR) process is less affected by such problems.

• Membrane and Water Treatment
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• v.7 no.1
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• pp.11-22
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• 2016

The characterization of treatment performance with respect to mixed liquor suspended solids (MLSS) concentration enables greater control over system performance and contaminant removal efficiency. Hybrid membrane bioreactors (HMBRs) have yet to be well characterized in this regard, particularly in the context of greywater treatment. The aim of this study, therefore, was to determine the optimal MLSS concentration for a decentralized HMBR greywater reclamation system under typical loading conditions. Treatment performance was measured at MLSS concentrations ranging from 1000 to 4000 mg/L. The treated effluent was characterized in terms of biochemical oxygen demand ($BOD_5$), chemical oxygen demand (COD), turbidity, ammonia ($NH_3$), total phosphorus (TP), total kjeldahl nitrogen (TKN), and total nitrogen (TN). An MLSS concentration ranging from 3000 to 4000 mg/L yielded optimal results, with $BOD_5$, COD, turbidity, $NH_3$, TP, TKN, and TN removals reaching 99.2%, 97.8%, 99.8%, 99.9%, 97.9%, 95.1%, and 44.8%, respectively. The corresponding food-to-microorganism ratio during these trials was approximately 0.23 to 0.28. Operation at an MLSS concentration of 1000 mg/L resulted in an irrecoverable loss of floc, and contaminant residuals exceeded typical guideline values for reuse in non-potable water applications. Therefore, it is suggested that operation at or below this threshold be avoided.

• Journal of Intelligence and Information Systems
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• v.3 no.2
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• pp.1-9
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• 1997

These papers propose an evolutionary algorithm for re-using output of waste fuel of light water reactor system in nuclear power plants. Evolutionary algorithm is useful for optimization of the large space problem. The wastes contain several re-useable elements, and they should be carefully selected and blended to satisfy requirements as input material to the heavy water nuclear reactor system. This problem belongs to a NP-hard like the 0/1 Knapsack problem. Two evolutionary strategies are used as a, pp.oximation algorithms in the highly constrained combinatorial optimization problem. One is the traditional strategy, using random operator with evaluation function, and the other is heuristic based search that uses the vector operator reducing between goal and current status. We also show the method, which performs the feasible teat and solution evaluation by using the vectorized data in problem. Finally, We compare the simulation results of using random operator and vector operator for such combinatorial optimization problems.

• Clean Technology
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• v.6 no.1
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• pp.39-49
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• 2000

Ultra Rapid Coagulation (URC) can dramatically remove pollutants loaded in wastewater by adding weighted coagulation additives (WCA) and recycling sludge into the coagulation basin to increase settling velocity and surface adsorption ability of floc. Also settling chamber together with lamella plates offers the high rate settling velocity, which can economically treat a considerable amount of pollutants like as combined sewage overflow (CSO) during the heavy rainfall and reduce the pollutants load into the receiving water for securing water source. It was estimated optimal configuration of settling chamber by using fluent model and the possibilities of reusing the sludge generated in this system.