• 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.

• Clean Technology
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• v.6 no.1
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• pp.27-38
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• 2000

A physicochemical process called Ultra Rapid Coagulation(URC) can dramatically remove organics, metals, and phosphates in wastewater by adding weighted coagulation additive(WCA) and recycling sludge into the coagulation basin to increase the growth rate and adsorption ability of floc. Also this process can improve floc settling rate than conventional coagulation process and reduce the pollutants loaded into the receiving water for securing water source. It was evaluated that WCA and sludge added have effects on the removal efficiency and estimated the possibilities of reusing the effluent from this process.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.353-359
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• 2015

This study introduces a resource recycling system in urban apartment complex using four different technologies. The four technologies, called 4G, include a production technology for reclaimed water (Green water), a biogas production technology from organic waste (Green biogas), a reuse technology of rainwater (Green rainwater), and urban agropark (Green pyramid). Green water is the technology for producing the reclaimed water from wastewater, rainwater and underground water, and the average concentrations of BOD, SS, T-N and coliform of reclaimed water were 7.8mg/L, ND (not detected), 4.9mg/L and ND, respectively. Green biogas is the technology for producing biogas and effluent after treating organic wastes (e.g. food waste and night soil) discharged from households, and the average production rates of hydrogen and methane were $0.33m^3/m^3/d$ and $0.24m^3/m^3/d$, respectively. Green pyramid, agricultural farm operated by biogas and reclaimed water, provides a healthy and recreational space for residents, and plant growth rates using treated water and reclaimed water showed height of 1.32cm and weight of 112.8g. Therefore, 4G technologies can improve the recycling rate and treatment efficiencies of waste and wastewater in an apartment complex.

• KSBB Journal
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• v.26 no.5
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• pp.400-406
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• 2011

This study was investigated to improve the saccharification yield of Ulva pertusa Kjellman by the high pressure homogenization process. It was found that the high pressure homogenization pretreatment effectively destructed the cell wall structures only by using water. The high pressure homogenization process was operated under various conditions such as 10000, 20000 or 30000 psi with different recycling numbers. The optimal condition was determined as 30000 psi and 2 pass of recycling numbers and the sugar conversion yields were 16.02 (%, w/w) of glucose and 14.70 (%,w/w) of xylose, respectively. In the case of enzymatic treating the hydrolyzates with 5 FPU/glucan of celullase and 100 units/mL of amyloglucosidase, 65.8% of carbohydrates was converted into glucose. Using the hydrolysates of Ulva pertusa Kjellman, 48.7% of ethanol was obtained in the culture S.cerevisiae. These results showed that the high pressure homogenization process could efficiently hydrolyze the marine resource by using only water for bioethanol production.

• Resources Recycling
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• v.8 no.1
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• pp.18-22
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• 1999

In order to utilize incineration fly ash of industrial wastes as resources, we present the recovery and separation of metals included in the fly ash by leaching with aqueous solution A great quantity of Cu, Pb, and Zn as well as a small amount oftoxic heavy metals are contained in the leach liquor of the fly ash, and the concentration of the ingredients of the fly ash depends on the industrial wastes which are fed into incinerators. In this paper, sequential Ieachiog operations are conducted using $H_2O$, $H_2SO_4$, $(NH_4)_2CO_3$ and NaOH as Icachants. Water soluble copper salt was leached by $H_2O$, Zn and Pb were separated by the NaOH leach liquor, and water insoluble copper was selectively leached as chelate ion with the $(NH_4)_2CO_3$ leach liquor of the third Ieaehant. Results show that the reduction percent of the fly ash in the leaching steps using $H_2O$, $H_2SO_4$, and $(NH_4)_2CO_3$ is 77%, and the other leaching procedures lose the weight of fly ash by above 60%.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.15-18
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• 2003

Development of the construction industry generally exhausts natural aggregate. Hence it is problem to the lack of supply and quality deterioration, so the resource saving and protection of environment is made an effort through recycling by-product. This study presents that fundamental properties of concrete which used cooper slag as alternate sand of low fineness modulus and plan of cooper slag as concrete aggregate. Testing factors are concrete's slump, air contents, unit weight and compressive strength. The results of this study are as follows; (1) Concrete slump is generally satisfied with the condition but is inferior to the others in substitution rates 30%. Also air contents are 3.1-4.1% and go up according to increase substitution rate. (2) Unit weight increase in 1.1% as the mixing ratio of cooper slag argument 10%. (3) compressive strength of cooper slag concrete is similar to plain and especially higher 11-15% in W/C 45%, 50%. So it seems that aggregate mixed cooper slag is suitable to low water-cement ratio mixture.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.253-259
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• 2005

Mine is quickly decline, Nowadays, many of abandoned and closed mines. AMD is abandoned surface water by accumulated yellowboy and caused environmental pollution by amount of heavy metals. The aim of this study waste lime was mixed with the sediment to produce an aggregate far the purpose of neutralizing the acidity and stabilization the heavy metal in the aggregate structure .to pozzolan effect. The result of Waste lime and sediment mixed(5%, 10%, 20%)ration by curing days(3, 7, 38days), After 28 curing days as 5% mixed waste lime leaching solution concentration of all heavy metals is satisfied with regulation limit. Also, the result of fractionate heavy metals to stabilization as 28 curing days very decrease exchangeable and reducible type, and then increase carbonate type. With the above results, waste lime the most effective for the sediment treatment and useful for the recycling waste resource.

• KIEAE Journal
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• v.2 no.4
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• pp.27-39
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• 2002

The fields of green building and ecological design have much to offer to those who are seeking to improve the ecological impact of schools and school grounds. These well established disciplines are particularly useful to existing schools considering renovations to make them more energy, water, and resource efficient as well as healthier places to work and play, Green building and ecological design principles and techniques are also very effective, of course, if incorporated into the design for brand new school buildings. The major concept of the Eco-school plan is to understand that the school consists of an ecosystem, so the design concept should focus on minimising impact but at the same time maintaining close contact with the environment. T his is becoming the basic concept in applying the Eco-school design to the new 21st century school building. This thesis is an analysis on the methods of application, based on careful examination of case-studies from the U.S.A about detailed plan element and design method, through the following six aspects ; (1) site use plan, (2) green plan, (3) water system plan, (4) materials and recycling of resources, (5) energy use plan, (6) indoor environment plan.

• Resources Recycling
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• v.16 no.5
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• pp.19-24
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• 2007

Reefs are the marine structure that can give resting, inhabiting, feeding and nursing spaces for a variety of fishes. Usually artificial reefs are made of cement and steels respectively in Japan as well as in Korea. However since resources deficiency has been getting serious, other materials are taken into consideration for the basic bodies of artificial reefs. About 300 thousand tons of waste agricultural plastic films are generated every yew in Korea, but no effective recycling techniques have been developed. In this sense, artificial reefs made of waste agricultural plastic films are the most representative symbol of the recycled products in the Resource Recycling Era. In particular, since these reefs could be made of the semi-cleaned waste agricultural plastic films that still contain high portion of soil, it is very environmentally friendly not only in manufacturing process but also in using under water. Furthermore they have some evident advantages as follows; 1) high fish swarming effect 2) good initial attachment of the marine growths 3) extremely low corrosion to brine 4) easy adjustment of the gravity 5) economical manufacture, transportation and jettison 6) excellent safety to ecosystem caused by lower elution of toxic substances 7) good recyclable property after application and so on.

• Resources Recycling
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• v.29 no.4
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• pp.15-30
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• 2020

Recently, it is increasing a amount of installed solar-cell rapidly, and end-of-life photovoltaic(ELP) modules are generated in according to the reduction of cell efficiency largely. Recycling of ELP modules are begun at an advanced nation already, but there are bring about environmental contamination and resource recovery problems owing to not treated ELP modules because of economic cost completely. First of all, there were researched basic study for treatment conditions of used solar cell inspection, dismantling of aluminum frame, crushing / grinding & separation of tempered glass, removal of back sheet & EVA film, leaching & precipitation recovery of valuable metals and treatment of waste water. Therefore, we establish optimum conditions through carried out of designed apparatus, installation of equipment, test operation & trouble shooting in scale of 1ton/day pilot plant test. Following to economic review, it does have the economic efficiency until to the case of tempered glass recovery, but does not have the economic value in case of total processes until to recover the valuable metals. However, there are guaranteed economic value if we are gained a large amount of the expenses through EPR supported system. It was confirmed the commercialized possibility of ELP modules recycling if there were established on the collecting ELP modules, reusing criteria, economical technology, enactment of directives and enforcement of EPR supported system efficiently.