• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.25-32
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• 2014

The amount of TPH contaminated soil treated at off-site remediation facilities is ever increasing. For the recycle of the treated-soil on farmlands, it is necessary to restore biological and physico-chemical soil characteristics and to remove residual TPH in the soil by an economic polishing treatment method such as phytoremediation. In this study, a series of experiments was performed to select suitable plant species and to devise a proper planting method for the phyto-restoration of TPH-treated soil. Rye (Secale cereale) was selected as test species through a germination test, among 5 other plants. Five 7-day-old rye seedlings were planted in a plastic pot, 20 cm in height and 15 cm in diameter. The pot was filled with TPH-treated soil (residual TPH of 1,118 mg/kg) up to 15 cm, and upper 5 cm was filled with horticulture soil to prevent TPH toxic effects and to act as root growth zone. The planted pot was cultivated in a greenhouse for 38 days along with the control that rye planted in a normal soil and the blank with no plants. After 38 days, the above-ground biomass of rye in the TPH-treated soil was 30.6% less than that in the control, however, the photosynthetic activity of the leaf remained equal on both treatments. Soil DHA (dehydrogenase activity) increased 186 times in the rye treatment compared to 10.8 times in the blank. The gross TPH removal (%) in the planted soil and the blank soil was 34.5% and 18.4%, respectively, resulting in 16.1% increase of net TPH removal. Promotion of microbial activity by root exudate, increase in soil permeability and air ventilation as well as direct uptake and degradation by planted rye may have contributed to the higher TPH removal rate. Therefore, planting rye on the TPH-treated soil with the root growth zone method showed both the potential of restoring biological soil properties and the possibility of residual TPH removal that may allow the recycle of the treated soil to farmlands.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.54-57
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• 2002

Pretreatment technologies are defined as technologies that prepare or condition dredged material for subsequent, more rigorous treatment processes. The objectives of this study are to test the feasibility of treating dredged sediment using pretreatment process(hydrocyclone, sedimentation basin, and flotation), and to estimate design parameters for a pilot-plant design. The final goal of the project is to recycle the dredged sediment that is otherwise reused as construction materials.

• 한국의상디자인학회지
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• 제20권2호
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• pp.47-62
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• 2018

This study examined recycled fashion design utilizing natural images for application to recent trends. This study is significant in that it presents the possibility of the development of recycled women's wear design by reflecting the characteristics and expressions of natural images and using denim material, which is the most common clothing material for everyday life. The results of this study are summarized as follows. First, five types of women's clothing was produced, pursuing a natural design with a soft and feminine silhouette. Second, the colors used were blue and white, which could represent nature. Third, as for materials, this study used clothing that was to be thrown away: four pairs of denim pants and two denim dresses. This study chose denim cloth, with its great value for reuse, because of the characteristics of the strong and durable fiber, because everyone has more than one article of clothing made from denim and because it can be easily sourced. Fourth, for textile motifs, this study expressed a peaceful natural scenery with tropical animals and plants. In addition, this study further emphasized natural images using transfer media printing. This study has significance in that it presented the possibility of recycled fashion design and expanded the range of utilization using transfer media printing, a dyeing treatment to reduce the environmental burden.

• International journal of advanced smart convergence
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• 제9권1호
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• pp.70-81
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• 2020

Plastics that we use and simply throw away have a life span of about 500 years and barely decompose. The practice of producing and using common plastics needs to be challenged. Until now, they have been useful in the industrial structure of mass production, but it can be said that there is a lack of research into new materials to introduce and apply in terms of material recycling. As a result of this, we have come to the uncomfortable realization of the fact that we cannot incinerate or reuse these precious resources indiscriminately. No matter how well-designed a product is, it has a competitive advantage if production and consumption activities, waste, collection, sorting and treatment are considered in terms of a continuous cycle, and in this respect, Extended Producer Responsibility (EPR) can help. We are implementing the EPR system, and active industrialization in the field of recycling is required, which is also a challenge for producers to participate actively in recycling and seek to save and recycle resources in design and manufacturing. Against this backdrop, We would like to examine the possibilities, through various studies and developments on product design of recyclable materials, which is being conducted mainly in Europe. In particular, we would like to examine the methods, and value of solving environmental problems and the active efforts to achieve this in the design world, and in particular the case of product design using recycled plastics.

• 상하수도학회지
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• 제18권2호
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• pp.181-187
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• 2004

The purpose of this study is to investigate the biofilm reactors capable of doing high efficiency treatment. Vertical fluidized bed biofilm reactor(VFBBR) and spiral fluidized bed biofilm reactor(SFBBR) was used for their performence in biodegradation of artificial sewage. The factors influencing the efficiency of those reactors were compared with difference of physical condition. They had same size but different structure to gain access of its unique characteristics. When recycle solution with flow rate of 22 mL/min and artificial sewage with flow rate of 2~10 mL/min were fed into two reactors in aerobic state, the average $COD_{cr}$, removal rate for biodegradation of SFBBR was greater than VFBBR. After reactor feed sewage was constantly maintained as flow rate of 4 mL/min and the recycle solution were changed to 10~32 mL/min respectively, the average $COD_{cr}$ removal rate of artificial sewage in SFBBR was greater than VFBBR. In this experiment for addition of support media into two reactors SFBBR was 4.1% excellent than VFBBR. Above all, SFBBR excelled VFBBR in boidegradation of organic matter in sewage.

• Environmental Engineering Research
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• 제25권3호
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• pp.400-408
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• 2020

Hydrodynamic study of Activated Sludge Process (ASP) is important to optimize the reactor performance and detect anomalies in the system. Residence time distribution (RTD) study has been performed using LiCl as tracer on a pilot scale aeration tank (AT) and ASP, treating the pulp and paper mill effluent. The hydraulic performance and treatment efficiency of the AT and ASP at different operating parameters like residence time, recycle rate was investigated. Flow anomalies were identified and based on the experimental data empirical models was suggested to interpret the hydrodynamics of the reactors using compartment modelling technique. The analysis of the RTD curves and the compartment models indicated increase in back-mixing ratio as the mean hydraulic retention time (MHRT) of the tank was increased. Bypassing stream was observed at lower MHRT. The fraction of dead zone in the tank increased by approximate 20-25% with increase in recycle rate. The fraction of the stagnant zone was found well below 5% for all performed experiments, which was under experimental error. The substrate removal of 91% for Chemical oxygen demand and 96% for Biochemical oxygen demand were observed for the ASP working at a hydraulic mean residence time 39 h MRT with a 20% recycling of activated sludge.

• Korean Membrane Journal
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• 제3권1호
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• pp.32-38
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• 2001

Using the hollow fiber membrane module in a lab-scale membrane bioreactor, the anoxic- oxic (AO) process for nitrogen removal was operated for about one year. For the influent wastewater containing 1,200-1,400 mg $1^{-1}$ of CODcr and 200-310 mg $1^{-1}$ of nitrogen, this process achieved a high quality effluent of less than 30 mgCOD $liter^{-1}$ and 50 mgN $liter^{-1}$. The removal rate of organics was above 98% at a loading rate larger than 2.5 kgCOD $m^{-3}$$d^{-1}$. When the internal recycle from the oxic to the anoxic reactor changed room 2n to 600% rout the influent flow rate, the nitrogen removal rate increased from about 70 to 90% at a loading rate of 0.4 kgT-N m-s d-1. The initial increase of transmembrane pressure (TMP) was observed after a 4-month operation while maintaining the flux and MLSS concentration at 7-9 1 $m^2$ $h^{-1}$ and 6,000-14,000 mg $1^{-1}$, respectively. The TMP could be maintained below 15 cmHg for an 8-month operation. The chemical cleaning with an acid followed by an immersion in an alkali solution gave better cleaning result with the membrane operated for 10 month rather than that only by an alkali immersion.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.296-300
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• 2001

In order to recycle the incineration ash (bottom ash and fly ash) generated from the incineration of municipal waste for a cement material, salts as well as heavy metal should be removed by the stabilization treatment. Most of these heavy metal and over 80% of salts are removed by a washing as a pre-treatment. However, wastewater which is another pollutant is generated by a washing, then proper treatment should be developed. First the characteristics of incineration ashes collected from two domestic full-sized incinerators were investigated and removal rate of salts and heavy metals from them also studied. The wastewater quality was compared to the criteria of the regulation by analyzing the characteristics of generated wastewater during the washing of incineration ash as a condition of liquid/solid ratio. Also, we tried to used this experimental results for the basic data to develop proper processing technique of municipal waste.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 추계 학술논문 발표대회
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• pp.49-50
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• 2014

Dredged sea soil contains various contaminants. First priority to recycle dredged sea soil is to pretreat it to remove various contaminants because recycling dredge sea soil without any pre-treatment may cause a secondary contamination due to the leaching of hazardous chemicals. In this study, pretreated dredged sea soil was used to investigate pozzolanic activity. The properties of pretreated dredged sea soil were investigated, the method for heat treatment was determined, and the compressive strength of mortar using dredged sea soil was examined to evaluate pozzolanic activity. According to the results, pretreated dredged sea soil has some possibility to work as a pozzolanic material. When dredged sea soil was heat treated for 90min at 550℃, compressive strength was shown to be comparable to that of plain cement mortar.

• 상하수도학회지
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• 제24권6호
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• pp.683-690
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• 2010

Renewable and unutilized energy (biogas power generation, wind power, solar, small hydro-power, sewage heat source, etc.) seems to be suitable to install for the sewage treatment facilities. There are 357 sewage treatment plants in 2007. 17 plants among these have been operating for self-supporting energy by using solar power, small hydro-power and biogas in 2008. Newly built sewage treatment plant of 96,000 $m^3$/day for a newtown is expected to get up to energy consumption of 10 GWh/yr. If solar energy, small hydro-power and biogas-equipments were applied to the new treatment plant, self-supporting energy of the new sewage treatment plant will get up to 56.1%. As a results, about 2,379ton $CO_2$/yr $CO_2$ emission reduction can be expected by using renewable energy. These efforts for self-supporting energy will lead sewage treatment plant to new energy recycle center.