간행물

한국폐기물자원순환학회지 KCI 등재 Journal of Korea Society of Waste Management

권호리스트/논문검색
이 간행물 논문 검색

권호

제30권 제3호 (2013년 4월) 12

Original Paper

1.
2013.04 서비스 종료(열람 제한)
In this study, we evaluated the applicability of upflow percolation test of European Standard as one of waste landfill stabilization index. Landfilled waste samples were taken from an old uncontrolled waste landfill site before and after 1 month aerobic treatment. Diameter of 10 cm and height of 30 cm column was filled with landfilled waste sample, and the column was saturated with deionized water for three days to reach equilibrium. And then upflow leachant was flowed by peristaltic pump with a linear velocity of 15 cm/day. Given schedule of sampling times leachate was sampled several times, and pH, COD, NH4-N, and Cl− of leachate were analysed. At the same time AT4 test, which is test for aerobic biochemical stabilization index, was performed. Upflow percolation test and AT4 test for landfilled waste samples before and after aerobic treatment showed significant statistical difference of results. From the results, upflow percolation test might be used as an complementary waste landfill stabilization index with AT4 test, and database of landfilled waste sample with different landfill ages should be accumulated to setup the proper waste landfill stabilization index.
2.
2013.04 서비스 종료(열람 제한)
The salt water generated from the salting process of kimchi production is difficult to treat biologically due to very high content of salt. When salt water is treated and discharged, it cannot satisfy the criteria for effluent water quality in clean areas, while resources such as the salt to be recycled and the industrial water are wasted. Therefore, in order to recycle salt water and improve the economy of kimchi production process, a basic study was conducted on the treatment using electrochemical oxidation of organic acids and organic matters existing in large volumes of salt water. The electrochemical treatment of organic matters has advantages over conventional methods such as active carbon absorption process, chemical oxidation, and biological treatment because the response speed is faster and it does not require expensive, harmful oxidizing agents. In this study, the electrochemical oxidation characteristics according to current density and pH were evaluated with acetic, lactic, and formic acids existing in large volumes of salt water. Acetic acid was refractory to electrochemical oxidation regardless of current density, while lactic acid showed high removal efficiency even at low amount of current. Furthermore, formic acid showed the highest current efficiency for the first 20 minutes and its removal rate increased together with the amount of current. In the experiments with the initial pH set to 4, 7, and 10, the removal rate of organic acids tended to be higher at lower pH values. Because NaCl was used as the electrolyte, HOCl was produced at pH 4 and OCl− increased at pH7. The germicidal power of HOCl is about 40-80 times higher than that of OCl−. For this reason, the generation of HOCl with excellent oxidizing power increased at pH 4 and the highest removal rate was achieved. Furthermore, as salt water contains various organic matters, an experiment on organic acid compounds was conducted to see the effects they have on electrochemical oxidation. As a result, it was found that lactic acid and formic acid could be used for simultaneous treatment even when they coexisted, whereas acetic acid is refractory to electrochemical oxidation. Furthermore, lactic acid showed the highest electrochemical treatment efficiency, followed by formic acid, and acetic acid.
3.
2013.04 서비스 종료(열람 제한)
This study was conducted to determine physico-chemical properties and degree of heavy metal contamination of sediments collected at Tongyong channel. From XRF and XRD analyses, all samples consisted of similar oxides and minerals. TOC ranged between 1.73 and 2.79%. Ignition loss ranged between 9.31 and 12.28%. Degree of heavy metal contamination of sediments was performed based on standards proposed by USEPA, Ontario sediment quality guidelines, index of geoaccumulation and total enrichment factor. In summary, sediment T9 was classified as moderately contaminated region based on standards of USEPA, index of geoaccumulation and total enrichment factor. In addition, T7 and T8 were classified as moderately contaminated region based on only USEPA standard. However, concentrations of Cu and Zn of T7 and T8 gradually increased to the level of T9 where it was close to Tongyong harbor. Therefore, the regions of T7, T8 and T9 need to be monitored and if possible required to remediate contaminated sediments.
4.
2013.04 서비스 종료(열람 제한)
We investigated the effect of temperature and pressure in breakthrough performance of various sorbents for dechlorination and desulfurization. Based on the results obtained during the desulfurization (Fe2O3, Fe3O4, ZnO) and the dechlorination (Na2CO3, NaHCO3, trona) screening tests, ZnO and trona were selected as preferred optimum sorbents. H2S breakthrough time corresponds to an effective capacity of approximately 11 g H2S/100 g of sorbent. Also, HCl breakthrough time corresponds to an effective capacity of approximately 5 g HCl/100 g of sorbent. ZnO and trona at high temperature of around 550oC display high sorption performance and removal efficiency for synthsis gas from waste gasification. Although there is an issue of CO2 recovery in hot gas cleanup technology for desulfurization, we have obtained an interesting new alternative hot gas cleanup system with heat budget merit.
5.
2013.04 서비스 종료(열람 제한)
The main purpose of this study is to identify the connection between urban characteristics and food wastes production. As a fundamental work for ‘Resource Recirculation’ in the metropolis, urban indicators is classified into traits of population, land use, residential construction, traffics, industries and economies in detail and then the extracted particular variables illustrate the relation of urban features and organic wastes by classifying urban indicators into traits of population, land use, residential construction, traffics, industries and economies. The scope of research is conducted in seventy-four district (Gu in Korea) in seven metropolises including Seoul to manifest the interrelationship of cities and wastes by correlation and multiple correlation analysis. According to this research, it concludes that the most influential variables for the existing food wastes treatment facility's location is the economic variables, property taxes than the population traits such as the number of population and employees. Particularly, the a noteworthy part is that the household is more critical element of wastes generation than the total population in population features.
6.
2013.04 서비스 종료(열람 제한)
This work presents an experimental study of the influence of lifting velocity on cake formation during filtration. For design of hot gas cleanup system using ceramic filter reactor, the most important consideration is coating conditions of sorbent in filter surface (for example : lifting velocity, coating weight of sorbent, pulsing interval and removal effect for dechlorination and desulfurization). We studied the optimum operation condition as paticle size and lifting velocity using a ceramic filter reactor at 550oC. Based on the results obtained during cold and hot test, optimum lifting velocity in a ceramic filter reactor was selected 0.68 m/s. Also, the removal behaviour of the ceramic filter during filtration was studied using differential pressure. Optimum removal efficiency for dechlorination and desulfurization accomplished at differential pressure condition over 74 mmH2O.
7.
2013.04 서비스 종료(열람 제한)
Establishment of emission standard of dioxins from crematories has been needed for their efficient management in korea. In this study, we investigate related regulation, guideline and management of crematory at home and abroad. Either dioxin legal basis or management of countries are compared and analyzed respectively. Crematories were distributed 51 place all over the country and total 265 crematories have been operated in 2000. Korea crematories have been operated 3 steps; incineration, cooling in furnace and collection of bone. This process is similar with Japanese process. But European process is different steps; incineration, keeping the temperature of furnace and collection of bone. In case of Korea, the resynthesis of dioxins in the cooling process due to the dioxin emissions higher than European process. This study has suggested three emission standards of dioxins from crematories based on survey of foreign standards and korean measurement data. The 1st suggested standard is 10 ng-TEQ/Sm3 in present facility, 5 ng-TEQ/Sm3 in new facility, the 2nd suggestion is 5 ng-TEQ/Sm3 in present facility, 1 ng-TEQ/Sm3 in new facility and the 3nd suggestion is 0.5 ng-TEQ/Sm3 in present facility, 0.1 ng-TEQ/Sm3 in new facility. When 2nd suggestion apply, at 2020 dioxin emissions(0.779 g-TEQ/yr) is expected to be approximately 71% reduction compared to 2010 year.
8.
2013.04 서비스 종료(열람 제한)
The objective of this research was to suggest the estimation method of air injection quantity for pre-stabilization of landfilled wastes in a sustainable landfill. A study on the determination of oxygen demand quantity of landfilled wastes, therefore, was conducted in two different experiments. Firstly, a batch test was performed in order to measure the oxygen quantity required to oxidize easily degradable organic matter under aerobic conditions. Secondly, a lysimeter experiment was carried out to assess the air injection period according to moisture content (20%, 30%, 40%, 50%) and to validate the oxygen demand quantity obtained by the batch test. This study assumed that landfilled wastes contain two different organic matters and two matters are sequentially utilized by microorganism. The first one provides the faster oxygen uptake rate that called the “easily degradable organics”. During the second phase of the aerobic decomposition, the other one provides the slower oxygen uptake rate that called the “moderately degradable organics”. Also, in this study, a modified logistic equation divided two terms (fractions of easily degradable organic and moderately degradable organic) was suggested to determine the oxygen demand quantity for easily degradable organic of landfilled solid waste. As a result, the oxygen demand quantity obtained by the batch test led to similar results compared with that of lysimeter experiment. Therefore, it showed that the modified logistic equation and batch test were appropriate for determination of oxygen demand quantity for decomposition of easily degradable organic matter. Also, air injection period for decomposition of easily degradable organic decreased with the increase of moisture content.
9.
2013.04 서비스 종료(열람 제한)
Linear type SFL (spent fluorescent lamp) can be classified by 3-banded lamp and general lamp. Linear type SFL is separated by the end-cutting technique to examine the distribution of mercury in the major components such as base cap, glass part and phosphor powder. In this study, the concentration of mercury is analyzed by DMA (Direct Mercury Analysis) method for major components in linear type SFL. From the results of mercury distribution for 3 companies, the concentration of mercury in 3-banded lamp is less than that in general lamp. And phosphor powder has greater than 80% of total mercury amount in SFL and the mercury concentration in phosphor powder is measured between 1,250 ppm and 1,740 ppm. The mercury concentration in phosphor powder can be changed by the type of lamp, company, and period of usage. KET and TCLP are carried out for phosphor powder, glass, and base cap to estimate the hazardous characteristic. From the results of KET and TCLP test for general lamp and 3-banded lamp, phosphor powder from general lamp and 3-banded lamp should be controlled separately by stabilization or other methods to reuse as a renewable material because the phosphor powder is determined as a hazardous waste.
10.
2013.04 서비스 종료(열람 제한)
Slaughter of cattle, pigs, and chickens is continuously increasing. Slaughter of chickens has especially increased by approximately 50% from 2003. The quantity of poultry slaughter waste is currently approximately 120,000 tons/year, and undergoes consigned treatment. Via this process, the waste must be used as a resource and an energy source. For this purpose, the waste volume can be reduced and solid fuel can be obtained from the THR (Thermal Hydrolysis Reaction) that consumes a small amount of energy. In this study, The test was conducted at a reaction temperature of 170-220oC and for 1h at the final temperature. According to the CST (Capillary Suction Time) and TTF (Time to Filter) evaluation, the dehydrating efficiency was good after the temperature reached 190oC, and did not significantly differ at the 190oC and higher reaction temperatures. The heating value of the dehydrated solid product was 7,000-7,700 kcal/kg, and its yield rate decreased from approximately 80% to 60% with the increase in the reaction temperature. The results of the BMP test also showed that the anaerobic digestion efficiency decreased at the reaction temperatures of 200oC and higher. From the overall evaluation of the dehydrating efficiency, solid fuel quality, and anaerobic digestion efficiency during the thermal hydrolysis of poultry slaughter waste, it is concluded that the optimal operating temperature is 190oC.
11.
2013.04 서비스 종료(열람 제한)
In this study, PCDDs/DFs concentrations in flue gases from 58 crematories and in fly ashes and bottom ashes (mainly bone) from several crematories were measured to grasp the present state of PCDDs/DFs emissions from crematories. The effects of several factors were discussed to prevent PCDDs/DFs emissions from crematories. Total concentration of PCDDs/DFs was ranged from 0.113 to 87.461 ng/Sm3 and toxic equivalent concentration was ranged from 0.019 to 15.347 ng-TEQ/Sm3. As the results obtained in this research, the following measures to reduce PCDDs/DFs emission are recommended for existing crematories: (1) keeping the temperature at < 800oC or < 850oC in main/secondary chambers during a whole cremation, (2) lowering the temperature in the dust collector, (3) installing the high efficiency dust collector and reducing dust concentration to less than 0.02 g/Sm3, and (4) installing the sampling point for monitoring of PCDDs/DFs.
12.
2013.04 서비스 종료(열람 제한)
This paper is a research on the end-of-waste (EoW) criteria of steel scrap. Government strengthens the management of the scrap recently, as pollution has been raised due to the improperly treated steel scrap. In this study, current status of steel scrap recycling was investigated through field survey in 2012, and classification and recycling standard of steel scrap in developed countries and institutions were investigated through literature survey in order to introduce optimal EoW criteria. As a result, contents of contaminants were selected as the most important recycling standards, and contents of contaminants in steel scrap was measured less than 0.5% in most of companies, but only one recycling company showed 10% of contaminants. EoW criteria for steel scrap was determined to be below 2% of contaminants. In this study, contaminants in steel scrap was defined as hazardous and pre-treated substances, considering the Korean industrial standards (KS). And EoW stage was determined by considering the regulation on resources and practices in field.