• Clean Technology
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• v.23 no.1
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• pp.80-89
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• 2017

The bubbling fluidized bed (BFB) reactor with a diameter of 0.1 m and a height of 1.2 m was used for experimental study of co-firing and emission characteristics fueled by sewage sludge (SS) and wood pellet (WP). The facility consists of a fluidized bed reactor, feeding system, cyclone, condenser and gas analyzer, The mean particle diameter and minimum fluidization velocity are $460{\mu}m$ and $0.21ms^{-1}$ respectively. SS produced from Korea and WP from Canada were examined. The various mixing ratios of WP were 20, 50, and 80% based on HHV. The equivalence ratio of 1.65, reactor temperature of $800^{\circ}C$, air flow rate of $100Lmin^{-1}$, and fluidization number of 4 were fixed in the BFB experiment. In TGA, the range of combustion temperature of SS was wider than that of WP. It represents that the combustibility of WP is higher than that of SS. The BFB reactor temperature was maintained between 800 and $900^{\circ}C$. CO emission of SS was high because of lower combustibility. $NO_X$ and $SO_X$ formation of SS were higher than that of WP since high nitrogen and sulfur contents of SS. CO, $NO_X$, and $SO_X$ formation were suppressed as the mixing ratio of WP was increased. The slagging and fouling tendencies show high in all test conditions.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.3 s.30
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• pp.69-78
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• 2004

Since 1995, One of the NGIS(National Geographic Information System) projects, the underground utilities project, has been finished in 2003. The 19 cities in korea for this project will use underground utilities management system using underground utilities database focusing on water and sewage system. However, special expert, technical and experience problem in computer environment has not been had in working department for water and sewage management and maintenance for each local government. The management and maintenance by underground utilities database by manual method is getting lowered a data qualify of underground utilities database because of the data omitting, error in writing and securing of the lasted database. Therefore, in this study, Application test for field workers using a mobile tool and environment analysis of wireless communication in Korea and application test of GPS receiver for mobile tools had been processed and made a mobile working environment. The efficient management and maintenance method for underground utilities database has been developed an off-line method for modification and update of database about general work which has a high working frequency because of the limitation of wireless communication environment. Also, the emergency working has been applied for on-line method.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.4
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• pp.129-137
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• 2000

In this study, biological treatment process of MWWT(Municipal wet-waste Treatment) has been developed through a moduling of the containerized closed ATAD(Auto thermal aerobic digestion) system & closed vertical dynamic acerator, which were used for food waste and cattle manure, respectively. Though biological process has several advantages such as low concentrations of heavy metals and salts, proper and stable C/N ratio and constant reaction rate against the process treating two wastes separately, it has a obstacles of salt concentration and much usage of bulking agent such as wood chip. After rapid oxidation in the boxed tower reactor for 5 days, the content of sewage sludge would be reduced 65% on around, might be mixed with the food waste that had been treated in the static closed reactor during 6 days and put in the secondary static reactor for curing. During composting process, the odor contained in the gas generated from the reactor was removed by passing it through a biofilter as well as the leachate was treated in the wastewater treatment facility. Consequently, it seemed to be possible to compost sewage sludge at mild and stable operating condition and at low cost through the biological ATAD process resulting in the production of organic compost satisfying the specifications regulated by itself.

• Journal of Satellite, Information and Communications
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• v.9 no.2
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• pp.96-100
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• 2014

Recently, the management system of wastewater treatment facility has magnified due to the stringent regulations for the protection of the environment, and a sewage treatment plant efficiency and research of the car development are activated in large facilities or industrial park. however, the existing sewerage disposal system and specific water quality monitoring network reliability for real-time transmission of this building is insufficient. In this paper, we proposed a local wireless network design for sludge multi meter data collection and control for measuring the concentration of the sludge efficiently. Also, the collected data over the local wireless network to transmitted to the central monitoring system and accumulate the data in real time to calculate statistics is possible to monitor the status of the sewage treatment facilities. The proposed system uses a short-range wireless networks of IEEE 802.15.4 and configures an IEEE 802.11 network which can monitor real-time status in central system. Also, we install a sludge multimeter and communication network in sewage treatment facilities and confirm the usefulness of the proposed technique by demonstrating its effectiveness.

• Journal of the Korean Society for Environmental Technology
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• v.19 no.6
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• pp.550-555
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• 2018

International Maritime Organization (IMO) is one of the most effective organizations in evolving international law for the protection and conservation of the marine environment. The IMO, MARPOL(Marine Pollution) 73/78 contains six Annexes that provide an overarching framework for the objectives of the international marine pollution. Annex IV was regulated by 64 th resolution in 2012 to control sea pollution from sewage. In 2014 large-scale wastewater treatment and nutrient removal device was developed with a grant from the Ministry of Oceans and Fisheries. A combined new process of Sequence Batch Reactor (SBR) and Membrane Bioreactor(MBR) was developed to overcome the pollution caused by shipboard sewage. In the present study, shipboard sewage wastewater was treated by mixing and aeration cycle in the newly developed SBR process. Furthermore, during analysis by NGS technique(Macrogen Co., Ltd.), dominant species of bacteria were found in the aeration tank of the Bench-scale wastewater treatment facility. Bacteroidetes and Gammaproteobacteria accounted for 27.1 % of the aerobicbacteria and 16.8 % of the anaerobicbacteria, respectively. Microorganisms play a vital role in shipboard wastewater treatment. A further detailed study is required to understand the precise role of the microorganisms in the wastewater treatment.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.937-945
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• 2016

Recently, Rural tourism in China is developing rapidly, however, the rural tourism remains unsatisfactory due to ignoring the landscape aspect which is considered as an integral part for rural tourism. Therefore, we aim to investigate the effect of the landscape elements on vitalization of rural tourism by evaluation of the landscape elements. To this end, we made a questionnaire survery concerning importance and satisfaction of landscape elements through factor analysis, and clamp IPA analysis. As the result, 1) Regional product, safety facilities and public parking lots are the primary considerations as primary factor. 2)Traffic facilities and accommodation should reflect regional characteristics; Garbage collection facility, food and beverage facilities, network and electricity facility should be rectified and maintained; Regaining the original nature characteristics of river and lake, Securing the integrity of the visual appreciation by shelter landscape for Sewage Purification. Our study results may provide a basic reference for the development and management of rural tourism attractions in China.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.9
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• pp.67-72
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• 2014

Inflow or outflow from the water treatment plant and the sewage water has potential energy. If this potential energy can be converted into electrical energy by water turbine generator, it can help to save energy because of the high capacity utilization. So recently, micro hydro power plant is reviewed in the water treatment facility. If generation capacity is low, induction generator is primarily used. If output capacity is low, generated power is supplied to the inside load. Induction generator can cause voltage drop by the inrush current at a start-up and requires reactive power for magnetization. In this study, we analyzed the flow of power and voltage variation against inrush current that occurs when the induction generator starts under the terms that loads of linear and non-linear of the water purification plant are used. Analysis results are that the voltage drop is within an allowable range and the power factor is slightly reduced by the need of reactive power.

• Korean System Dynamics Review
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• v.4 no.2
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• pp.71-94
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• 2003

The purpose of this dissertation is to build a development density control model and estimate optimum developmental density level for a sustainable urban growth management. To develop the model, system dynamics modeling approach was used. The model was developed to analyze how urban growth, transition, and decay occur depending on the interaction among population, houses, industry structure, land and urban infrastructure such as road, water supply, and sewage treatment facilities. The model was applied to Anyang city to estimate optimum density level. Extensive computer simulation was conducted to find out the maximum numbers of population, industry structure, houses, and cars that can be adequately sustained with the current Anyang city's infrastructure capacity. The computer simulation result shows that the city is overpopulated by some 90,000 people. It nab analyzed that 20％ increase of existing capacity of urban infrastructure is necessary to support current population of Anyang city. To reduce the population to the adequate level whereby the current urban infrastructure can sustain, the current city regulation on floor area ratio needs be strengthened at least 20％ to 35%.

• Environmental Engineering Research
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• v.21 no.2
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• pp.211-218
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• 2016

Cheonggye-cheon is a partly restored urban stream located in central Seoul. We monitored fecal contamination using three different fecal indicators, total coliforms (TC), fecal coliforms (FC) and E. coli, to assess differences in each indicator on days of varying weather conditions. Presumptive TC, FC and E. coli colonies were identified by their 16S rRNA sequences. The results showed that enumeration of E. coli provided a better reflection of fecal contamination of the stream than TC and FC. The main sources of contamination were the inflow of fecal-polluted groundwater from the vicinity of a subway line and two inflowing streams. The fecal contamination was worsened on days with heavy rain because untreated sewage from a collecting facility flowed into the stream. Moreover, growth potential of fecal indicator (E. coli) in situ induced by algal exudates was measured. Our results suggest that an appropriate standard based on E. coli rather than TC and FC should be established for improving water quality management strategies of Cheonggye-cheon in the future.

• Journal of Environmental Impact Assessment
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• v.15 no.2
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• pp.111-119
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• 2006

In Korea, an environment-friendly concept of "rain re-cycling" was initially introduced in apartment complex planning and designs in the late 1990s. Although its application cases are extremely few, with the growing importance of rainwater utilization, introduction of rainwater management facilities in urban areas began to drawn keen attention. In urban areas also, plans to introduce rainwater management facilities in apartment complexes as infrastructure improving living environment, such as sewage treatment facilities are very urgently required. In order to introduce rainwater management facilities as infrastructure in an apartment complex, apartment complex cases that had introduced the facilities were reviewed first. In this study, a few applied rainwater management facilities in an apartment complex were surveyed(Infiltration barrel, Rubble porosity storage tank, Underground storage tank). As a result, problems in introducing rainwater management facilities in apartment complexes in Korea were identified.