• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.6
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• pp.44-52
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• 2007

Recently, oystershell wastes cause serious environmental problem and the need for the researches on the recycling of oystershell have been increased and various methods are already in operation. Field plate bearing tests and numerical analysis were performed to investigate the bearing capacity of oystershell filled geotextile gabion which utilized the waste oystershell at the coastal oyster farm site. The waste oystershell mixed soil specimens were prepared for the laboratory test and field test in terms of varying blending ratio of granite soil and oystershell. Based on the cyclic plate load test results, the spring constant, subgrade modulus of ground, and the reinforcing parameters were determined. The field plate load test results indicate that the bearing capacity of the soil ground with the oystershell mixed ratio of 20% is greater than that of the original ground. Two-dimensional numerical analysis was evaluated the expected deformation in the given conditions. Analysis results show a similar characteristics on bearing capacity with the results of the field plate load test. These findings suggest that the oystershells are very promising construction materials for landfill and earth embankment in coastal area.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.228-229
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• 2018

In the construction industry, we have set goals such as reduction of greenhouse gas emissions and reduction of energy use. In particular, reduction of CO₂ emissions in the concrete manufacturing process, reduction of industrial waste and industrial wastes into concrete The zero-emission level of reuse as a resource is under review. On the other hand, the cost of stone is expensive due to small quantity production of domestic stone production in order, it is difficult to carry and construct with heavy material, and it takes long time to construct. In order to solve the shortage of supply and demand of natural stone, various kinds of stone powder, artificial stone made by putting stone texture on the surface of mortar or concrete, fiber reinforced plate, tiles and the like are increasingly used. In this study, the artificial stone using slag and recycled aggregate instead of natural stone was fabricated and the strength characteristics were evaluated for its applicability and feasibility.

• Journal of ILASS-Korea
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• v.15 no.4
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• pp.195-201
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• 2010

Due to its carbon-neutral nature, biogas generated from anaerobic digestion or fermentation of biodegradable wastes is one of the important renewable energy sources to reduce global warming. It is mainly composed of methane and various inert gases such as $CO_2$ and $N_2$, and the actual composition of biogas significantly varies depending on the origin of anaerobic digestion process. Therefore, in order to effectively utilize this fuel as an energy source for electricity, it is important to develop power generation engines which can successfully apply biogas with significant composition variations. In this study, efforts have been made to develop a diesel-biogas duel fuel engine as a way to achieve such a stable power generation. The effects of diesel fuel injection quantity and pressure on stable combustion and engine performance were investigated, and an impact of diesel fuel atomization was discussed. The engine test results show that there exists a 2 stage combustion which consists of diesel pilot fuel burning and premixed biogas/air mixture burning in dual fuel engine operation and optimum diesel injection parameters were suggested for biogases with various compositions and heating values.

• Proceedings of the Korea Society for Simulation Conference
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• 1998.10a
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• pp.12-16
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• 1998

The purpose of this paper is to develop a knowledge-based real-time decision support system to support decision makers for efficient berth operation of Inchon Port. In these days, the efficient berth operation has been many studied. The berth operation rules differ from port to port and the problem is highly dependent on natural, geographical and operational environment of port. In Inchon Port, the ship's entrance into port and departure from port is extremely affected by the status of dock and berth because of capacity restriction. First, we analyzed the specific characteristics of Inchon Port such as dock based on the data of 1997. And then, we construct the database of experts knowledge for berth utilization. Finally, we build the real-time decision support system for the efficient berth operation of Inchon Port to make the better berth allocation in case of not only regular scheduling but also dynamic scheduling such as delay in berth operation and exchange of ship between berths. The DSS is developed with graphic user interface(GUI) concept to help the user determining user interactive updating of the port status. Then this DSS will be provide decision maker with an efficient and fast way to berth allocation, and reduce wastes of time, space, and manpower in Inchon Port operation.

• KSBB Journal
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• v.16 no.4
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• pp.370-375
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• 2001

For the production of new exo-biopolymers from microorganisms, an exe-biopolymer producing bacterial strain was isolated from the composter used in composting of organic wastes. Bacteriological properties of this strain and physicochemical properties of producing exo-biopolymer were investigated. The isolated strain was identified as Enterobacter sp. through its morphological, cultural and physiological characteristics. The results of color reactions, CPC (cetyl pyridinium chloride) precipitation and infra red absorption spectral analysis indicated that this exo-biopolymer was presumed as an acidic polysaccharide with uronic acid. This polysaccharide was identified as hetero-polysaccharide consisting of galactose, mannose and galacturonic acid by gas chromatography, and the molecular weight of exopolysaccharide purified by gel chromatography were about 370,000 daltons. The polysaccharide solutions(0.50-2.0%, w/v) exhibited non-Newtonian flow behavior with pseudoplastic property and showed the ability of gel formation at above 1.5% (w/v) of polysaccharide concentration.

• Clean Technology
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• v.10 no.3
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• pp.139-148
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• 2004

The recovery of stainless steel fiber by removing cutting oil from grinding swarf, which is classified as specified wastes, was investigated. Swarf loaded with grinding oil was regenerated by supercritical carbon dioxide. And, the effects of temperature(313.15K-323.15K), pressure(10MPa-30MPa) on regeneration efficiency were studied. Regeneration effiency was increased as the pressure was increased. Also, at the same pressure, the experiments at higher temperature were more efficient for regeneration. The experiment results was predicted by applying a one-parameter mathematical model assuming linear desorption kinetics. The predicted value showed good agreement with experimental data.

• Environmental Engineering Research
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• v.23 no.3
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• pp.323-329
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• 2018

The municipal solid waste (MSW) management system in one of the Class II Indian cities i.e. Rishikesh was studied and analysed to identify the key issues in solid waste management in the city. A total of 329 solid waste samples from 47 households were collected to characterize the household solid waste (HSW). The average (HSW) generation rate was 0.26 kg/c/d and it was composed of organic waste (57.3%), plastics (14%), paper (10.9%), and glass and ceramic (1.3%) and other materials (16.5%). There was an inverse relationship between household waste generation rate and family size (p < 0.05). The MSW management system practiced in Rishikesh is unsound. There is no waste segregation at source, no provisions of composting and no recycling by formal sector. The collection and transportation of waste is inadequate and inappropriate. Collected waste is dumped in open dumping site without scientific management. Following are some recommendations for developing a sustainable solid waste management system in Rishikesh city: (1) sensitize people for segregation at source; (2) promote reduction, reuse and recycling of wastes; (3) promote community based composting; (4) provision for 100% door to door collection and; (5) formalize the informal sectors such as rag pickers and recycling industries.

• Journal of Korean Society on Water Environment
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• v.22 no.3
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• pp.498-503
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• 2006

Adsorption features of $Cd^{2+}$ on waste tire particles have been investigated for the purpose of enhanced wastes recycling along with the development of an economic process for wastewater treatment. The isoelectric point of waste tire particles was found to be ca. pH 7 and the adsorbed amount of $Cd^{2+}$ was increased with pH under experimental conditions. The variation of the adsorption behavior of $Cd^{2+}$ with pH was well explained by the change of the electrokinetic potential of waste tire particles according to the pH. Adsorption of $Cd^{2+}$ was observed to reach its equilibrium within 45 minutes after the adsorption started under experimental conditions and followed the Freundlich model well. Kinetic analysis showed that the adsorption reaction of $Cd^{2+}$ was second order and thermodynamic estimation substantiated the endothermic behavior of $Cd^{2+}$ adsorption. As the amount of adsorbent increased, more adsorption of $Cd^{2+}$ was accomplished and the adsorption capacity of adsorbent was found to be enhanced by its pre-treatment with NaOH. Also, the adsorption of adsorbate was promoted as the ionic strength of wastewater was increased.

• Journal of Korean Society on Water Environment
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• v.18 no.2
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• pp.159-168
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• 2002

A lab-scale Reverse Osmosis(RO) membrane reactor was installed to investigate the membrane permeability, characteristics of membrane fouling at each conditions, and performance of elimination at different trans-membrane pressure(TMP) in the liquid fertilizer accumulated system. Experimental setup was divided to three different TMP conditions. As a result of experiment, permeability of RO membrane was proportional to the increase of TMP and temperature. After experiment was completed, two types chemical cleaning(remove the organic foulant and inorganic foulant) was done, and recover rate of permeability was each 99.8, 99.7 and 99.7%, respectively. From this experimental data, membrane fouling could be determined that the most of it was recoverable in this system, and major reason of fouling was concentration polarization. Elimination rate of solute substance in the liquid fertilizer indicated very stable(above 99%), except ammonia nitrogen, and the most stable elimination rate was investigated at the highest TMP condition (Run 3).

• Journal of Mushroom
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• v.18 no.2
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• pp.141-144
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• 2020

In this study, we attempted to find alternative materials to replace Cotten seed meal(CM) using the wastes of bean sprouts by-product in bottle cultivation of Pleurotus ostreatus. In Proximate analysis, the protein content of BW was slightly lower than that of CM, but the growth characteristics of mushrooms were similar to those of control when byproduct of bean sprouts was used. In addition, the amino acid composition of fruit body did not show a significant difference in the treatment section. Therefore, it is judged that BW could be a suitable substitute for CM in the cultivation of Pleurotus ostreatus.