간행물
한국폐기물자원순환학회지 KCI 등재 Journal of Korea Society of Waste Management
- 발행기관 한국폐기물자원순환학회
- 자료유형 학술지
- 간기 연8회
- ISSN 2093-2332 (Print)2287-5638 (Online)
- 수록기간 1984 ~ 2018
- 주제분류 공학 > 환경공학 공학 분류의 다른 간행물
- 십진분류KDC 539DDC 628
권호리스트/논문검색
제30권 제5호 (2013년 7월) 14건
Original Paper
1.
2013.07
서비스 종료(열람 제한)
Deacidification of waste cooking oil such as, palm oil or soybean oil, using supercritical carbon dioxide (scCO2) extraction has been widely investigated for reusing waste cooking oil. The deacidification process using scCO2 has been carried out under various experimental conditions temperature range between 40 and 100oC, pressure range between 20 and 35 MPa, CO2 flow rate range between 10 and 40 g/min, and extraction time range from 1 to 7 hours. The purified waste oils were characterized by their acid value and peroxide value measured. The optimized conditions were deduced in this paper at the temperature of 80oC, pressure of 20 MPa, and CO2 flow rate of 40 g/min. At the optimized operating condition the peroxide value was existed between 40 and 100. Also 80% of the purified oil was recovered. The properties of the purified oil were shown as similar to those of the pure oil.
2.
2013.07
서비스 종료(열람 제한)
Difference in immobilization effect of heavy metal-contaminated soil between two different amendment methods was evaluated; 1) both of steel slag (i.e., consisted in solid phase) and soluble phosphate (i.e., consisted in liquid phase) were simultaneously applied to contaminated soil (i.e., simultaneous amendment methods) and 2) soluble phosphate and steel slag was applied sequentially to the contaminated soil (i.e., sequentially amendment methods). The application rate of stabilizers to soils was determinated based on weight/weight ratio of 5% for steel slag and PO4/Pb molar ratio of 2.0 for phosphates, respectively. To identify difference of immobilization effect to test soil, three different soluble phosphates, such as Na2HPO4·12H2O, Ca(H2PO4)2·H2O and (NH4)2HPO4 were used. The sequential amendment was 6 ~ 27% more effective than the simultaneous amendment in terms of the immobilization efficiency for Pb, Cu, and Cd in the contaminated soil. There was little difference in case of Zn. Among the three phosphates tested, (NH4)2HPO4 was clearly the most effective. Residual form of heavy metals concentration in sequentially methods is higher than those in simultaneously methods. At the same time, more exchangeable and carbonate-bound forms of heavy metals in simultaneously methods were observed than in sequentially case. These result implies that the sequential amendment method was more effective than the simultaneous amendment method in terms of heavy metal immobilization in the contaminated soil.
3.
2013.07
서비스 종료(열람 제한)
The objective of this study is to manufacture an efficient activated carbon fiber (ACF) assemblies filter. Cellulose acetate and phenolic resin were dissolved in acetone and coated on a 2 cm-long and 2 cm-wide stainless steel mesh. Various concentrations of cellulose acetate and phenolic resin in acetone solution were examined for the extent of coating on the stainless steel mesh using a thermogravimetric analyzer (TGA), a surface area analyzer (BET) and a microscope. As a result, the best quality of coating on the stainless steel mesh was obtained with 2 wt,% cellulose acetate and 10 wt,% phenolic resin in acetone solution. The ACF filter was also impregnated with ZnCl2, KOH, H3PO4 and Na2CO3, respectively to enhance its adsorption capacity. Iodine number increased by impregnating with the chemical compound in the following order: KOH > ZnCl2> Na2CO3> H3PO4. Iodine numbers for the ACF filters impregnated with ZnCl2 (ACFz) and KOH (ACFK) were found to be 972 ~ 1,117 mg/g and 987 ~ 1,183 mg/g respectively.
4.
2013.07
서비스 종료(열람 제한)
The drying and fuel technologies for sewage sludge have been developed due to the prohibition of ocean dumping and new renewable portfolio standard. This study was performed to enhance the quality of sludge derived fuel and compare drying characteristics for thickened and digested sewage sludge at different temperature, pressure and mixing oil conditions in oil vacuum evaporation system. In addition to investigate calorific value and characteristic analysis of dried sludge. The thickened and digested sludge used in this study were taken from municipal sewage treatment plant and coagulated using polymer (C-310P) in laboratory. The drying rate was increased with temperature and degree of vacuum and it was 25 mL/kg-sludge·min at 110oC and –450 mmHg. The moisture content of dried sludge products showed very low within 1% in the range of 0.4 ~ 0.8%. The evaporation rate of thickened sludge was lower than digested sludge and the constant evaporation period was also shorter. Compared the effect of waste cooking oil and refined waste petroleum oil on drying efficiency, the waste cooking oil showed more effective than refined oil in evaporation rate and drying time. The carbon and hydrogen contents of dried sludge with refined oil were higher than waste cooking oil. The low heating value of thickened dried sludge was higher than digested dried sludge about 400 kcal/kg and both of dried sludge showed high calorific value more than 4,000 kcal/kg.
5.
2013.07
서비스 종료(열람 제한)
In this study, the thermo-catalytic hydrogenation using corn stark and wasted palm kernel shell was carried out for the production of hydrocarbon compounds in direct biomass liquefaction. The conversion of biomass in direct biomass liquefaction over Mo-based catalyst increased with increasing the reaction temperature and the content of the volatile matter contained in biomass and the corn starch was more available than the wasted palm kernel shell. And then, the conversion was about 97.9% using corn starch and was about 92.4% using wasted palm kernel shell at 400oC. It was confirmed that the liquefied products obtained after the thermo-catalytic reaction were C6, C7, C8-typed hydrocarbon compounds.
6.
2013.07
서비스 종료(열람 제한)
To produce bioethanol from cellulosic biomass, the cellulosic biomass needs pretreatments for high efficiency saccharification. This study, thus, aims to evaluate the efficiency of several pretreatments using vegetables as a cellulosic biomass among food wastes. The evaluated pretreatment methods were acid treatment, ammonia treatment and hydrogen peroxide treatment, which were used by individual and/or incorporating method. As a result, the concentration of reducing sugar increased 4 ~ 15 times and that of glucose increased 5 ~ 26 times compared to the samples without pretreatment. The acid treatment as an individual treatment was the most efficient, and the efficiency of incorporating treatment showed higher than that of individual treatment. Besides, there were differences in the composition and content of hydrolyzed sugars although the saccharification efficiency was similar by the method of each pretreatment.
7.
2013.07
서비스 종료(열람 제한)
Several experiments have done to investigate the removal of hydrogen sulfide(H2S) synthetic gas from biogas streams by means of chemical absorption and chemical reaction with 0.1 M – 1 M Fe/EDTA solution. The hydrogen sulfide of biogas was bubbled through an gas-lift column with Fe/EDTA resulting in the formation of sulfur particles. Wide range of optimal operating conditions were tested for both Fe/EDTA solution and the biogas, and the optimal ratio of Fe/EDTA concentration for efficient removal of hydrogen sulfide was found. The roles of Fe/EDTA were studied to enhance the removal efficiency of hydrogen sulfide because of oxidizing by Fe+3/EDTA. The motivation of this investigation is first to explore the feasibility of enhancing the toxic gas treatment in the biogas facility. The biogas purification strategy affords many advantages. For instance, the process can be performed under mild environmental conditions and at low temperature, and it removes hydrogen sulfide selectively. The end product of separation is elemental sulfur, which is a stable material that can be easily disposed of with minor potential for further pollution. The process to address over 90% removal efficiency of hydrogen sulfide does offer considerable advantages unrealized.
8.
2013.07
서비스 종료(열람 제한)
Ceramic welding backing material is a mullite-cordierite composite that is currently being used for welding processes in plant and shipbuilding. It is the optimal material for welding processes thanks to its extremely low thermal expansion coefficient and strong resilience against high temperature. However, due to the pollutants from welding such as iron and carbon, the entire amount of ceramic welding backing material is being land-filled after a single-time use. In this study, ceramic welding backing material was mixed with clay and kaolin to be used as a new ceramic body. A composition with 20 ~ 50% of ceramic welding backing material showed sufficient plasticity, and when fired at 1,250oC, it was deemed available for ceramic block and others with the porosity of 2.27 ~ 5.94%, water absorption ratio of 0.99 ~ 3.96% and bending strength of 720 ~ 810 kgf/cm2. In addition, color ceramic body, which was made from a waste welding backing material, of which iron was partially removed, added with 3wt% of high temperature pigment and fired at 1,250oC, displayed the unique color of the pigment, meaning that waste welding backing material could be used for ceramic bodies of a variety of colors.
9.
2013.07
서비스 종료(열람 제한)
Through industrial developing, electronic waste is occurred by short lifespan of electronic products. This study discusses an approach of the eco-efficiency for waste PCB (Printed Circuit Board) recycling process through environment and economic analysis. The recycling of waste PCB 1 kg has 1.89E + 00kg CO2 eq. of global warming potential and 2.84E −02 kg antimony eq. of abiotic resource depletion. In terms of economy, this process costs 6,601.91 KRW per 1kg waste PCB recycling. Use of economic and environmental result, when compare with same amounts of virgin metal, environmental-efficiency of GWP (Global Warming Potential) is at 4.16E + 00 and ARD(Abiotic Resource Depletion) is at 2.91E + 00. And compare with secondary metal, environmental-efficiency of GWP is at 2.11E + 00 and ARD is at 8.49E − 01. In addition economic-efficiency is at 1.19E + 00. The results of optimization of this process will be increased. This study will show the process economical and environmental decision making
10.
2013.07
서비스 종료(열람 제한)
To improve the conversion rate of the saccharification liquid of food wastes, containing a mixture of pentose and hexose, to bioethanol, this study aimed to investigate the fermentation characteristics by P. stipitis which is used in the fermentation of xylose as well as glucose as a substrate. Saccharification liquid of cellulosic food wastes such as Chinese cabbage, cabbage, and Chinese chive contained hexose, mainly glucose and fructose, and pentose, mainly xylose and trace disaccharide. The pentose in reducing sugar occupied 32%, meaning that the conversion rate to ethanol could be increased by the fermentation of such a pentose. From the result of ethanol fermentation, although the rate of fermentation by P. stipitis was slower than by S. coreanus, it was verified the consumption of pentose as well as hexose in the process of the forced air injection, consequently, it was confirmed the increase of ethanol yield.
11.
2013.07
서비스 종료(열람 제한)
In this work, lightweight brick was prepared from aluminum dross, MS and MBA. Aluminum dross is discharged as by-product through the process of aluminum smelting. It can be used as foaming agent, because it produces hydrogen gas due to the reaction with alkali activator. In this study, the specific gravity and compressive strength of prepared brick was discussed with the addition of aluminum dross. Compressive strength, flexural strength and specific gravity was 36 MPa, 2.6 MPa and 1.48 at mixing ratio of 0.9wt% aluminum dross, respectively. The physical property of brick was debased with the addition of aluminum dross. Because the pore size was bigger in accordance with the addition of aluminum dross.
12.
2013.07
서비스 종료(열람 제한)
Thermogravimetric (TG) analysis was used to investigate the effects of carbonization and solvent extraction on the combustion characteristics of sewage sludge. Initial temperature (IT) and peak temperature (PT) represent combustion characteristics in carbonized sludge (CS). The sludge extracted (ECS) from CS using solvent extraction exhibited higher IT and PT than raw sludge (RS). First, indicate that carbonization was carried out at two different temperatures, 300 and 400oC, to produce CS300 and CS400; then, compare the corresponding IT and burnout temperature (BT). All IT and PT values for ECS300 were lower than those values for RS and CS. The activation energy determined for the combustions of CS300 and ECS300 was lower than the one for the combustion of RS. The ECS300 activation energy (combustion zone of char) was determined to be 90.7 ~ 99.1 kJ/mol, lower to the range of 109.3 ~ 126.9 kJ/mol for coal.
13.
2013.07
서비스 종료(열람 제한)
According to the statistics of the Ministry of Environment, the emission of sewage sludge is increased by 7 ~ 9% yearly. In the future, it will be increased continuously because of extension of sewage disposal plants, high class treatment for removing nitrogen and phosphorus. The objective of this study is to examine the possibility of the carbonization of the sewage sludge by pyrolysis. The pyrolysis behavior of the sewage sludge was investigated by the thermogravimetric analysis as a function of heating rate. In the pyrolysis studies measurements in weight loss was made and reported as a function of test temperature. To minimize energy consumption used for drying sewage sludge, naturally dried sludge were applied evaluate characteristics of thermal and carbonization treatment using a fixed-bed reactor. The most effective treatment temperature of carbonized material production was 400oC. The temperature of highest total yield of char and oil was 500oC. In the pyrolysis studies measurements in weight loss was made and reported as a function of test temperature. According to the result, the optimum pyrolysis temperature of sewage sludge were found to be ranged from 100oC to 600oC, respectively. About 91% of pyrolysis was completed between 100oC and 600oC. If applying the carbonization, it can be easily utilized as the replaced resource of energy(fuel) in the countries whose energy resources are insufficient, like our country.
Technical Note
14.
2013.07
서비스 종료(열람 제한)
Biomass resources might be recognized as a promising way to alter fossil fuels, such as petroleum oil, natural gas and
coal and to prevent the emission of greenhouse gases which will bring about global warming. Therefore many countries
have tried to identify and secure available biomass resources. In this study, the energy potential of Korean biomass
resources, such as agricultural biomass wastes, municipal solid wastes, and livestock wastes, was analyzed and calculated
by using various data. The available energy potential in 5 major cities in Korea was over 3.5 M TOE. Especially the
municipal solid wastes was over 1.5 M TOE, so the conversion of municipal solid wastes might be easily adopted.
