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
제33권 제7호 (2016년 10월) 12건
1.
2016.10
서비스 종료(열람 제한)
Estimation and Comparison of Methane Oxidation Factor using a Mass Balance Method at a Landfill Site
The objective of this study was to determine the CH4 oxidation factor (%) and the CH4 oxidation rate (g m−2 d−1) in landfill cover soil. To quantify in-situ rates of CH4 oxidation, CH4 and CO2 fluxes were measured on a landfill site using the static chamber technique. The CH4 oxidation factor obtained in this study through the mass balance method ranged between 41% and 61%, which is much higher than the Intergovernmental Panel on Climate Change (IPCC) default value of 10%. The higher CH4 oxidation factor derived in this study can be explained by the CH4 bottom flux in addition to the soil texture. The CH4 oxidation factors were observed to increase with decreases in CH4 bottom flux. Therefore, when CH4 bottom fluxes are high in a landfill, using a gas collection system can enhance CH4 oxidation factor. The CH4 oxidation rates were estimated to range from 16.6 g m−2 d−1 to 20.8 g m−2 d−1. In addition, this study was conducted to evaluate the effects of vegetation on the CH4 oxidation factor. The results showed that the CH4 oxidation factors for bare soil, vegetated soil, and soil adjacent to a gas well were 57%, 70%, and 44%, respectively. The results indicate that vegetation on landfill covers can increase the CH4 oxidation factor because of increasing soil porosity.
2.
2016.10
서비스 종료(열람 제한)
Korea belongs to a very fast growing market for coffee consumption and at the same time the amount of coffee waste has also been proportionally increased, But until now on only a small amount of coffee waste is utilized as a fertilizer, even it contains many kinds of valuable substances for agricultural purpose. With several treatment-technology of coffee waste a higher productivity can be established in combination with additional supplements. In this study the roasting effect of coffee waste was compared in combination with other substances in terms of mushroom cultivation. Roasted coffee waste contains many kinds of bio-active compounds and minerals and such components are very useful for plants, fungi and mushroom cultivation. We tried to develop a more effective and efficient medium for mushroom. Mushroom belong to typical health food and the consuming amount is also increasing. Pleurotus ostreatus is one of the most popular mushroom. The growing market and fast cultivation has been demanding. A qualified media with reasonable price is an important factor, because why coffee waste has a good value for mushroom production. In this study Pleurotus ostreatus spores were cultivated in roasted coffee waste with addition of variable substances, for example, bentonite and hydrogel. By the counting number of spores the effect of these added substances were compared.
3.
2016.10
서비스 종료(열람 제한)
In this study, the chemical flow of butadiene in the Korean chemical material industry was analyzed by chemical flow analysis. In addition, the atmospheric emissions estimation equation was calculated. The results of the product-specific material flow analysis showed that 1,450,076 tons of butadiene have been used in the domestic chemical material industry. Of that, 28.2% was used for SBR, 29% for BR, 21.2% for ABS, and 21.5% for the manufacture of other rubber products. In addition, butadiene has been used in the production of final products, such as automotive supplies and equipment, tires, shoes, and consumer electronics products. Among them, it was found that the major product at 39% in the production of tires. About 56.7 tons of butadiene found to have been emitted into the atmosphere by the calculated expression. The results of the regional analysis showed butadiene was treated in five cities and seven provinces, with the largest amount of butadiene used in Chungnam. The results of standard industrial classification showed that, among the 23 divisions of the standard industrial classification, butadiene flow in the manufacture of synthetic resins or other plastic materials was found to account for about 70% of the total.
4.
2016.10
서비스 종료(열람 제한)
It is projected that swine manure solids can be used for heating agricultural facilities. Therefore, this study focused on the possibilities of using swine manure as a solid fuel instead of composting it. Moisture content, ash content, volatile content, calorific value, TGA (thermogravimetric analysis), and elements in the swine manure were determined. After dehydrating the manure completely in a drying oven, its calorific value and ash content were measured. They appeared to be 3,517 kcal/kg and 16.6%, respectively, which satisfies the standard value of livestock solid fuel: heating value of 3,000 kcal/kg or above and ash content of 30% or below. Based on this result, it is concluded that using swine manure solids as a solid fuel is possible. Furthermore, when the chemical elements of C, H, O, N, S, Cl, etc. in the manure were analyzed, there was 33.75 ~ 45.98% of carbon and 31.55 ~ 41.20% of oxygen, which indicates that most of the manure was composed of combustible materials. However, there were cases where the percentage of water content in the manure exceeded 70%, implying that costs for dehydration would become expensive because it needs to be lowered to 20% in order to be used for energy source. Therefore, in order to use the swine manure as an energy source, minimizing the manure’s percentage of water content at the farm without any outside financial input is the biggest task to be solved.
5.
2016.10
서비스 종료(열람 제한)
An electrochemical treatment has great efficiency for the removal of non-biodegradable material and it has high applicability in wastewater treatment due to its short operating time. The purpose of this study using an electrochemical process is to provide fundamental data on the cutting fluid treatment, which has difficulties in the treatment of nonbiodegradable material. The results are as follows. Experimental data in relation to applied voltage and concentration of NaCl are outlined. With no addition of NaCl, and an applied voltage of 5 V, 10 V, or 15 V for 60 mins, the removal rates of CODMn were 29.87%, 55.32%, and 67.27% for each voltage. The removal rates of CODCr were 39.51%, 70.73%, and 85.37%, respectively. The removal rates of CODMn and CODCr increased with increasing applied voltage. These experimental results showed that the removal rate of COD with varying concentrations of NaCl (0 mM, 5 mM, 10 mM) increased increasing NaCl concentration.
6.
2016.10
서비스 종료(열람 제한)
The chemical leak accidents cause a large number of casualties in the short term and secondary environmental pollution in the long term. In the case of the hydrogen fluoride (HF) leak accident in Gumi City, Gyeongsangbuk-do, Korea, the fluoride ion concentration in crops located near the HF leak accident area was detected to be in the range of 99 ~ 13,029 mg/kg and in woody stems in the range of N.D. ~ 6,789 mg/kg. We also identified the correlation relationship between the range and the contamination degree. The order of degree of fluoride contamination of crops was leaf > stem epidermis > inside the stem. However, in another case of accidental HF leak in Hwasung City, Gyeonggi-do, Korea, because the concentration of fluoride ion in the crops was detected in the range of N.D. ~ 45 mg/kg, it is difficult to make a decision about whether HF affects the crops or not. In this study, with the suggestion of the identification of leak accident impacts by checking the contamination characteristics and condition of HF in terms of diffusion distance from the accident point, we prevent damage from secondary environmental pollution and prepare for similar accidents in the future.
7.
2016.10
서비스 종료(열람 제한)
The flow of products containing valuable metal resources after discharging to waste means that it is necessary to form a plan to improve resource circulation to enhance the circulation of metal resources. In this study, waste resource circulation flow analysis of products containing cobalt and palladium after disposal was performed by classifying five stages: (1) discharge/import, (2) collection/discarding, (3) pretreatment, (4) resource recovery, and (5) product production/export. The mobile phone was one of products which were the most generating cobalt. Discharged cobalt was kept for processing or was produced as pure cobalt, cobalt oxide, or cobalt sulfate, and was used as a raw material for locks, speakers, AlNiCo magnets, tire, batteries, etc. The total amount of cobalt in the waste products was 994 tons and the recycling rate was 53.7%, indicating that 543 ton of cobalt was recycled. Palladium was discharged from waste electrical and electronic products, precious metals, petrochemical catalysts, vehicles catalysts at the end of their life, and medical equipment (dental). The palladium recovered by pre-treatment and resource recovery was recycled as a metal resource or exported. The amount of palladium recycled was 2.412 tons, of which a total of 2.512 or 96% tons is estimated to be recycled. Future research may be necessary to suggest institutional improvements, including the waste resource classification and market expansion for the recycling in the five steps based on the results of this study.
8.
2016.10
서비스 종료(열람 제한)
In this study, hydrothermal carbonization is used to recover energy from sludge. This hydrothermal carbonization is a feasible sustainable energy conversion technology to produce biofuel for renewable energy. The experiments were conducted at 170oC up to 220oC for a 30-min holding period to determine the optimum conditions for hydrothermal carbonization in a lab-scale reactor to apply to a scale-up reactor (1 ton/day). The biochars from sludge were assessed in terms of dewaterability characteristics and fuel properties. The results showed that the optimum temperature of labscale hydrothermal carbonization was 190oC. The 1 ton/day hydrothermal carbonization pilot plant operated at 190oC. The biochar had higher energy content but the char yield sharply decreased. Therefore, an energy of about 49% could effectively be converted from sludge biomass. This sludge from municipal wastewater treatment is a potential energy resource because sludge is composed of organic substances.
9.
2016.10
서비스 종료(열람 제한)
Recycling of incineration ash generated from domestic waste incinerators is important from environmental and energy conversation aspects. The main components of bottom ash are CaO, Al2O3, SiO2, P2O5, MgO, and Fe2O3, similar to geological components. However, it also contains heavy metal ions such as Cu2+, Pb2+, and Cr6+. The ash material was sintered at 1100 ~ 1150oC by adding pink kaolin to stabilize those heavy metals. The study analyzed the crystal phase and absorption rates of the sintered material for application as a sub-base layer material for roads and conducted tests for the requirements for sub-base layer materials for roads, such as CBR test, quantity of abrasion, and liquid limit. Considering the plasticity, water absorption, and compressive strength of the road base, the mixture with 76wt% bottom ash and 24wt% pink kaolin after sintering at 1,120oC, showed CBR test result of 33.0, quantity of abrasion of 30.3, and liquid limit of NP (no plasticity). These result indicated the possibility of using bottom ash as a sub-base layer material, which satisfied requirements of the standard specification for road construction.
10.
2016.10
서비스 종료(열람 제한)
Anaerobic mesophilic batch tests of food waste and food waste leachate collected from food waste treatment facility were carried out to evaluate their ultimate biodegradability and two distinctive decay rate coefficients (k1 and k2) with their corresponding degradable substrate fractions (S1 and S2), respectively. Each 3 liter batch reactor was operated for more than 60 days at substrate to inoculum ratio (S/I) of 0.5 as an initial total volatile solids (TVS) mass basis. Result of Ultimate biodegradability of 74 ~ 83% for food waste and 85 ~ 90% for food waste leachate were obtained respectively. The readily biodegradable fraction of 85 ~ 93% (S1) of food waste Biodegradable Volatile Solids (BVS, So) degraded within the initial 15 days with a range of of 0.151 ~ 0.168 day−1, whereas the rest slowly biodegradable fraction (S2) of BVS degraded for more than 53 days with the long term batch decay rate coefficients of 0.009 ~ 0.010 day−1. For the food waste leachate, the readily biodegradable portion (S1) appeared to be 92 ~ 94% of BVS (So), which degrades with of 0.172 ~ 0.206 day−1 for an initial 15 days. Its corresponding long term batch decay rate coefficients were 0.005 ~ 0.009 day−1. It is recommended that the hydraulic retention times of mesophilic anaerobic digesters be 16 days for the food waste and 15 days for the food waste leachate, respectively. However a safety factor should be considered when designing a full scale plant.
11.
2016.10
서비스 종료(열람 제한)
Generally, metal working fluids (MWFs) are used to reduce friction in metalworking processes. In addition to mineral oils, MWFs contain many chemical substances, such as anticorrosive agents, extreme-pressure additives, and stabilizers, as well as high concentrations of organics and ammonia nitrogen. Accordingly, MWFs must be managed to advanced treatment for hydro-ecological conservation. This study investigated the removal efficiency of ammonia nitrogen from MWFs according to operating time, applied voltage, distance between electrodes, and NaCl concentration using aluminum in a batch-type reactor. The experimental results were as follows: First, without NaCl, removal efficiencies of ammonia nitrogen were 69.6%, 37.9%, and 22.7%, when the distance between electrodes was adjusted to 1, 4, and 7 cm, respectively, at 15 V for 60 min. Secondly, without NaCl, removal efficiencies of ammonia nitrogen were 49.5 and 90.9% when the voltage was adjusted to 5 V and 10 V, respectively, for 60 min and 94.6% at 15 V for 40 min. Lastly, with the addition of NaCl 10 mM, the removal efficiency of ammonia nitrogen was 40.3% and 11.5% greater than that of no addition of NaCl at 5 V for 60 min and at 10 V for 30 min.
12.
2016.10
서비스 종료(열람 제한)
There has been an increasing trend for the installation of pipeline waste collection systems for household waste in the massive complexes of new houses in Korea. This trend is attributed to the advantages of the system, which can reduce traffic congestion and keep the residential areas clean. The system also prevents odors and facilitates the easy discharge of waste by residents any time. However, several problems have been identified, whereby the installation and maintenance costs of the system are considerable and the system does not support separate discharge of recyclable wastes. For example, residents normally discharge food waste separate from disposable municipal solid waste at the waste drop, but some of the systems mix them at the bottom and transfer them together, which goes against resources recirculation, an important point of current waste management principles. Investigation into other countries’ experiences of the installation and operation of these systems will be a good lesson for Korea. Therefore, we studied Japan’s case, because they have a number of these systems between the 1970s and early 1990s as government-subsidized model projects led by the Ministry of Construction and the Ministry of Health and Welfare. However, it was done at a time when the reduction of discharge of wastes and recycling were not considered significant owing to rapid economic development, only focusing on the convenience of waste collection and transportation. Furthermore, energy consumption and greenhouse gas emissions were not priorities to be considered. Now that the systems are not suitable for the current resource recycling-oriented society, none have been installed since 2002, and many facilities have been closed already, with a few facilities operating with difficulties. Therefore, the installation of pipeline collection systems for household waste should be further considered with appropriate measures to avoid the precedent experiences of Japan.
