• Journal of Environmental Impact Assessment
• /
• v.18 no.6
• /
• pp.453-460
• /
• 2009

In order to provide fundamental data for developing high-grade(high-quality and low-pollution) Refuse Derived Fuel(RDF), we analyzed caloric value and HCl content by Municipal Solid Waste(MSW) type. The caloric value was analyzed using calorimeter and HCl content was analyzed using mercury(II) thiocyanate method. In case of paper type the caloric value was 3,060~3,608kcal/kg and the HCl content was 239~6,135ppm. In case of vinyl-plastics the caloric value was 5,946~9,888kcal/kg and the HCl content was 429~455,771ppm. According to the result of quality assessment by MSW type, the calroric value of vinyl-plastics type was showed higher than that of paper type and in case of HCl content the paper type was showed lower than vinyl-plastics type. So, We mixed paper and plastic wastes. The caloric value of mixed MSW(paper and plastics) was 5,046~9,125kcal/kg and the HCl content was 239~6,135ppm. Also, The caloric value of packaging waste(film-plastics) was 5,982~8,045kcal/kg. Therefore It is possible to develop high-grade Refuse Derived Fuel through suitable mixing of paper and plastic in municipal solid waste.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.12
• /
• pp.1561-1572
• /
• 2022

Plastic pollution has been recognized as a serious environmental problem, and microbial degradation of plastics is a potential, environmentally friendly solution to this. Here, we analyzed and compared microbial communities on waste plastic films (WPFs) buried for long periods at four landfill sites with those in nearby soils to identify microbes with the potential to degrade plastics. Fourier-transform infrared spectroscopy spectra of these WPFs showed that most were polyethylene and had signs of oxidation, such as carbon-carbon double bonds, carbon-oxygen single bonds, or hydrogen-oxygen single bonds, but the presence of carbonyl groups was rare. The species richness and diversity of the bacterial and fungal communities on the films were generally lower than those in nearby soils. Principal coordinate analysis of the bacterial and fungal communities showed that their overall structures were determined by their geographical locations; however, the microbial communities on the films were generally different from those in the soils. For the pulled data from the four landfill sites, the relative abundances of Bradyrhizobiaceae, Pseudarthrobacter, Myxococcales, Sphingomonas, and Spartobacteria were higher on films than in soils at the bacterial genus level. At the species level, operational taxonomic units classified as Bradyrhizobiaceae and Pseudarthrobacter in bacteria and Mortierella in fungi were enriched on the films. PICRUSt analysis showed that the predicted functions related to amino acid and carbohydrate metabolism and xenobiotic degradation were more abundant on films than in soils. These results suggest that specific microbial groups were enriched on the WPFs and may be involved in plastic degradation.

• Smart Structures and Systems
• /
• v.22 no.4
• /
• pp.433-440
• /
• 2018

Pavements porous concrete is a noble structure design in the urban management development generally enabling water to be permeated within its structure. It has also capable in the same time to cater dynamic loading. During the technology development, the quality and quantity of waste materials have led to a waste disposal crisis. Using recycled materials (secondary) instead of virgin ones (primary) have reduced landfill pressure and extraction demanding. This study has reviewed the waste materials (Recycled crushed glass (RCG), Steel slag, Steel fiber, Tires, Plastics, Recycled asphalt) used in the pavement porous concretes and report their respective mechanical, durability and permeability functions. Waste material usage in the partial cement replacement will cause the concrete production cost to be reduced; also, the concretes' mechanical features have slightly affected to eliminate the disposal waste materials defects and to use cement in Portland cement (PC) production. While the cement has been replaced by different industrial wastes, the compressive strength, flexural strength, split tensile strength and different PC permeability mixes have depended on the waste materials' type applied in PC production.

• Journal of Environmental Science International
• /
• v.18 no.10
• /
• pp.1181-1187
• /
• 2009

Results for application of RDF(Refuse Derived Fuel) to selected wastes in metropolitan and small and medium cities are as follows. The physical characteristics of waste are paper, plastic, food waste, and so on. The proximate analysis in P city showed 20.2% of moisture, 71% of combustible material, and 8.8% of ash on annual average. That in G city showed 31.6% of moisture, 59.5% of combustible material, and 8.9% of ash. Ultimate analysis in P city showed 52.04% of carbon, 7.02% of hydrogen, 28.80% of oxygen, 0.66% of nitrogen, and 0.09% of sulfur. Heating value was 3,363 kcal/kg. Ultimate analysis in G city showed 50.85% of carbon, 6.56% of hydrogen, 29.86% of oxygen, 0.79% of nitrogen, and 0.12% of sulfur. Heating value in the G city was somewhat lower than that in the P city with 2,632 kcal/kg. Thus, application of RDF in metropolitan city was more effective than that in small and medium cities. Heating value in mixture for the P city was lower than that in waste of the volume rate waste charge system alone by 143 kcal/kg. In proximate analysis, moisture, and combustible material were likely to be more adequate to RDF.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.33 no.6
• /
• pp.505-509
• /
• 2020

The development of diesel power generation is predominantly geared toward island areas or ships because diesel exhibits weak scale-merit characteristics and power quality problems, which are associated with environmental pollution. However, a new energy paradigm, distribution energy resource (DER), has been emerging as a renewable energy source due to the existing structural problems in waste disposal and complex factors such as the conversion technology of waste emulsified oil (WDF). By combining extended producer responsibility (EPR) support and renewable energy certificates (REC), including waste energy REC 0.25 for other bioenergy and REC 1.0 for power transactions, an adequate profit model can be built through self-energetic power generation, thereby drawing keen attention from related industries. Therefore, if WDF is used appropriately as a high-quality engine fuel, it can lead to the development of various fields such as novel renewable energy sectors, waste management, and EPR-related industries. This study is intended to produce WDF using plastic waste by using it as engine-generator fuel. Moreover, we investigate ways to improve the quality and suitability of WDF as an engine fuel.

• Geomechanics and Engineering
• /
• v.20 no.6
• /
• pp.497-503
• /
• 2020

In the Kingdom of Saudi Arabia, the shallower depth of the earth's crust is composed of loose dune or beach sand with soluble salts. The expansive behavior of salt bearing soil, fluctuation of ground water table and extreme environmental conditions offer a variety of geotechnical problems affecting safety and serviceability of the infrastructure built on it. Despite spending money, time and other resources on repair and rehabilitation, no significant attention is paid to explore the root causes of excessive differential settlement and cracking to these facilities. The scientific solution required to ensure safety and serviceability of the constructed infrastructure is to improve the strength and durability properties of the supporting ground. In this study, shredded plastic is employed as a low cost and locally available additive to improve strength characteristics of the desert sand. The study shows a remarkable increase in the shear strength and normal settlement of the soil. A seven (07) degree increase in angle of internal friction is achieved by adding 0.4 percent of the shredded plastic additive. The effect of different proportions and sizes of the plastic strips is also investigated to obtain optimum values. Such a long-lived solution will seek to reduce maintenance and repair costs of the infrastructure facilities laid on problematic soil along with reduction of environmental pollutants.

• Archives of Plastic Surgery
• /
• v.41 no.4
• /
• pp.418-420
• /
• 2014

Congenital melanocytic nevus consists of congregations of nevomelanocytes. It is found in approximately 1% of new born infants. Congenital melanocytic nevus needs to be excised before it transforms into a malignant lesion. Many strategies have been attempted for the removal and reconstruction of the nevus. Serial excision enables wound closure to be accomplished with a shorter scar than if the original lesion was elliptically excised in a single stage and reorientation of the scar closer to the relaxed skin lines. The routine utilization of an elliptical serial excision as a standard method of closure often leads to the formation of elongated scars and waste of skin. The "Cogwheel pattern" serial excision is a new technique for reducing the size of the nevus efficiently. Reducing the final scar length, distributing the tension over many directions, and having the chance of decrease in operation numbers are ultimately achieved with the use of the "Cogwheel pattern" serial excision.

• Resources Recycling
• /
• v.26 no.1
• /
• pp.69-77
• /
• 2017

Used small household appliances(small e-waste) consists of a variety of complex materials and components. The small e-waste is mainly composed of plastics and an important potential source of waste plastic. The black plastics, particularly are very difficult to separate by resin type and therefore these are mainly recycled in the form of a mixtures. In the present study, the sorting technologies such as gravity and electro static separation, near-infrared ray(NIR) and IR/Raman optical sorting separation on mixture of black plastics were analyzed and their limitations on sorting process were also investigated. The Laser Induced Breakdown Spectroscopy(LIBS) spectrum of each black plastics was used for identification of black plastics by resin type, and after analyzing the normalization operation, Principal Component Analysis(PCA) was carried out. The spectrum data was optimized through PCA process. In order to improve the identification accuracy and sorting efficiency of black plastics, it is necessary to design a classifier with high efficiency and to improve the performance and reliability of the classifier by applying the field of intelligent algorithms.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.05a
• /
• pp.365-368
• /
• 2021

In this study, a plastic bottle recycling bin system that utilizes an infrared sensor was implemented. The proposed system consists of a recognition unit, a control unit, an alarm unit, and a driving unit. The recognition unit detects the plastic bottle, measures the distance between the plastic bottle and the infrared sensor, extracts the value of the bottle, compares the extracted value with a standard range, and then transmits the control value to the control unit if the extracted value of the bottle is outside the standard range. In this case, the result of the presence or absence of a brand label or bottle cap is transmitted to the controller. The control unit opens the entrance of the recycling bin or alerts the alarm unit according to the result value transmitted from the sensor unit. In order to implement the proposed system, the recognition unit was implemented with an infrared sensor, and the control unit was made with an Arduino IDE controller, based on the C programming language. Additionally, the recognition unit and the control unit are able to communicate using analog signals. The proposed system accurately judges the presence or absence of a brand label and bottle cap of plastic bottles according to a predetermined algorithm. It then blocks the entrance of the recycling bin when a brand label or bottle cap is still attached. As the amount of waste discharged per person is relatively high and the majority of such waste is incinerated rather than recycled, the system proposed in this study is expected to increase the recycling rate of plastic bottles.

• Proceedings of the Korean Institute of Resources Recycling Conference
• /
• 2001.05b
• /
• pp.19-22
• /
• 2001

In recent years, the creation of waste recycling society has been required to cope with the traditional ways of waste treatments. In accordance with the package recycling law in force, calls for the developments of new waste treatment techniques suitable for 21st century are growing higher. A new ash melting furnace system named Eco Burner Ash Melting Furnace System has been developed. It is a burner type ash melting system in which the fluffs made of the plastics segregated from municipal solid wastes are directly fired at high temperature in the furnace. This system provides an economical ash melting system because plastic wastes or paper scraps that have heretofore been considered hard to recycle are used in compensation for fossil fuel. In this paper, we describe the ash melting test results obtained from a substantiative facility.