박상우 Sang-woo Park

DOI:10.9786/kswm.2015.32.7.639

Abstract

This study aims to discuss measures to combat climate change pertaining to the waste sectors in the EU and Japan. The EU aims to secure 20% of its total energy consumed from renewable sources and to reduce the emission of greenhouse gases by 20% by 2020. This study investigated the amount of waste-based energy produced and confirmed that it makes a significant contribution to renewable energy sources. The amount of energy produced differs according to the type of waste utilized and the size (population) of the country and these factors should be taken into account when establishing response measures. In Japan, policies have been introduced to promote the recovery of energy and to reduce the greenhouse gases emitted by incinerators. In particular, the country has been promoting a high level of efficiency by differentiating the government subsidy funding according to the energy recovery rate. This study confirmed that the utilization of waste resource energy has made a significant contribution to reducing the emission of greenhouse gases in the member countries of the EU and in Japan. Korea needs to establish similar policies to increase the contribution of energy from waste resources in the future.

Key Words

Post-2020, INDC, Waste resource, Energy recovery

전태완 Tae-wan Jeon , 황동건 Dong-gun Hwang , 정미정 Mi-jeong Jeong , 엄남일 Nam-il Um , 강영렬 Young-yeul Kang , 정성경 Seong-kyeong Jeong , 정용우 Yong-woo Jeong , 홍수연 Soo-youn Hong , 신선경 Sun-kyoung Shin

DOI:10.9786/kswm.2015.32.7.650

Abstract

There is legal uncertainty and ambiguity with regards to the classification and disposal of sludge generated from glass etching process. Moreover, secondary effect on the environment such as corrosion of landfill construction by the sludge produced in glass etching process was observed in waste landfill site. As part of response to the parliament’s request for the relevant data and local media coverage, exhaustive investigation of glass etching process was required. Accordingly, we conducted an exhaustive investigation of 8 glass etching manufacturers. Glass etching business is one of the businesses that have seen rapid growth since 2010 with the development of semiconductor and electronics industry, and glass etching producers are mostly located in Gumi, Cheongju, Sejong, Gongju, and Cheonan cities. In this study, we investigated the harmful effects of wastes generated from the glass etching process, how those wastes are classified and treated, problems arose from the process, and secondary effects on the environment observed in waste landfill site. The study found that cyanide, lead, mercury, trichloroethene, and perchloroethene were not detected in the sludge produced from glass etching process, and hexavalent chromium, copper, and arsenic were either not detected or reported at very low level, which was below the threshold concentration level of designated waste. In contrast, pH of sludge produced from glass etching process was between 1.7 and 2.3, pH of hydrofluoric acid used for glass etching showed acidic value of 1.5, which suggests that the classification system of such hazardous substance requires reconsideration.

Key Words

Glass etching, Process sludge, Complete survey, Hazardous characteristics

김종범 Jong-bum Kim , 류재용 Jae-yong Ryu , 윤조희 Cho-hee Yoon , 이춘식 Chun-sik Lee , 장성호 Seong-ho Jang , 김한수 Han-soo Kim

DOI:10.9786/kswm.2015.32.7.657

Abstract

Volatile Organic Compounds in Urban Atmosphere are contributing largely at significant risks to human health and have caused serious problems such as ozone formation. This study is to identify the effects of DRE (destruction and removal efficiency) and carbonization of styrene when using the electron beam energy. The irradiation intensity of electron beam energy was 1 mA, 5 mA and irradiation time were 5 sec and 10 sec. The styrene was completely destroyed at 5 mA. Main by-products was aerosol particles. Aerosol particle formation was increased with increasing irradiation intensity. Most of the by-products of particle were carbon.

Key Words

Volatile organic compounds, Styrene, Electron beam, Carbonization, By-product, Particulate

남윤미 Yunmi Nam , 장용철 Yong-chul Jang , 최종현 Jonghyun Choi , 이진홍 Jin-hong Lee

DOI:10.9786/kswm.2015.32.7.665

Abstract

With a growing concern of greenhouse gas (GHG) emissions due to climate change, many activities and efforts on the greenhouse gas reduction have been implemented in solid waste sectors. Since recycling is the major management option for solid waste in Korea, it is important to estimate the reduction of the greenhouse gas emission during recycling processes. In this study, two common methodologies, Prognos method of EU and waste reduction model (WARM) method of USA, have been critically reviewed and compared to estimate the reduction for recycling of waste paper in terms of system boundary, recycling processes, and emission factors. As a common point of two methodologies, the reduction factors for the paper recycling have been developed by subtracting the recycled product emissions from the virgin product emissions to get the greenhouse gas savings. While the recycling losses and transportation are considered in two methodology development, there are a number of differences between the methodologies in system boundary, transportation distance and forest carbon sequestration. As a result, it caused the difference in final greenhouse gas reduction factor of paper recycling. The reduction factor was -820 kgCO₂eq/ton in Prognos method, while -3,891 kgCO₂eq/ton was found in the WARM method. When both methods were applied to recycling of waste paper in Korea, the greenhouse gas reductions by the Prognos method and the WARM method were found to be 3,485.2 tCO₂eq/day and 2,248.8 tCO₂eq/day, respectively. When the carbon sequestration by forest is considered in the WARM method, the reduction rate was estimated to be 16,538.3 tCO₂eq/day. The main reasons for such difference can be attributed to system boundary and forest carbon sequestration. Especially, forest carbon sequestration can be an important factor in Korea that usually manufactures papers from imported pulp from abroad. This study implies that the applications and results of both methods to estimate greenhouse gas reduction by waste recycling should carefully reviewed and acknowledged before use due to the different assumptions and results that are anticipated.

Key Words

Waste recycling, GHG reduction, Prognos, WARM, Paper waste

김우일 Woo-il Kim , 윤철우 Cheol-woo Yoon , 엄남일 Nam-il Um , 최효현 Hyo-hyun Choi , 강영렬 Young-yeul Kang , 전태완 Tae-wan Jeon , 신선경 Sun-kyoung Shin

DOI:10.9786/kswm.2015.32.7.675

Abstract

Phospho-gypsum (PG) is a by-product generated from wet process of phosphoric acid production. The recycling rate of PG is only fifteen percents for the recycling uses, such as cement retardant, gypsum board, plaster, functional fertilizer. In the result of pH analysis, PG, neutralizing gypsum, soil, and dredged soil were 3.5, 7.4, 8 to 8.8, and 7.8, respectively. In case of the electric conductivity (EC), PG, neutralizing gypsum, and soil were 2,990 μS/cm, 2,230 μS/cm, and 84 ~ 99 μS/cm, respectively. In heavy metal contents of PG, As and Cd could be measured under environmental standards in Korean Soil Environment Conservation Act. In inorganic elements of leaching PG, Ca and Na were 629 mg/ L and 13 mg/L, respectively, but As, Cd, and other elements were detected under the regulated levels in Korean Waste Management Act. Also, among inorganic elements in PG, the leaching ratio of Mg and Cd were 7.3%, 1.3% respectively. In neutralized PG, leaching ratio of Mg and Cu were 1.9%, 1.4% respectively compared with other elements. In sequential batch leaching test, the leaching concentrations of As and Cd were rapidly decreased after 2 days. F^- and Ca were steadily decreased until 2 days and 8 days, respectively, and no more change since then. In case of SO₄ ^2-, it fell at constant rate to 1,600 ~ 1,800 mg/L. As seen in Ca leaching curve relating to pH value, the leaching decreased with increasing pH.

Key Words

Phosphogypsum, Recycling use, Sequential batch leaching test

하신영 Shin Young Ha , 김인수 In Soo Kim

DOI:10.9786/kswm.2015.32.7.686

Abstract

The composting characteristics of BM sludge and the control sludge were compared. Feasibility of using coffee grounds as a bulking agent was examined, along with sawdust. It was observed that composting of BM sludge had a faster rate of reaction than with the control sludge, and higher temperatures were reached. When using coffee grounds as a bulking agent, the caffeine in the coffee seemed to absorb the odors, allowing a composting with almost no odors. Moreover, when coffee grounds used as the bulking agent, total organic matter content increased by approximately 17% over sawdust, while total nitrogen increased by 49%, and available phosphorus by approximately 3%.

Key Words

Coffee grounds, Beneficial microorganism sludge, Composting, Bulking agent

Dong Hyun Lim , Kwang Seok Ki , Sun Ho Choi , Su Bum Park

DOI:10.9786/kswm.2015.32.7.693

Abstract

This study was conducted to evaluate effects of chopped and non-chopped rice straw on characteristics of silage-based total mixed ration (TMR) according to the particle size, laceration, and in situ dry matter (DM) degradation. The three rice straw silages as low moisture unchopped (LMUC; 32.75% of moisture, unchopped), high moisture unchopped (HMUC; 42.05% of moisture, unchopped), and high moisture chopped (HMC; 44.71% of moisture, chopped to 30 cm lengths) were tested. Samples were collected at every 5 minutes from 10 min of pre-mixing to 50 min. The percentage of >19 mm in LMUC and HMC was decreased to 7.23% and 7.74% (p < 0.05), respectively, and the percentage of 8 mm > was increased to 5.81% and 5.24%, respectively. Furthermore, the laceration of forage by a TMR mixer showed that there was little change in the reduction of 1.26% in HMC, but was reduced to 7.53% and 16.06% in LMUC and HMUC, respectively. The peNDF_>8 was maintained 17 ~ 18.5% of the optimal requirement level for 15 to 45 min mixing in LMUC and for 30 to 50 min mixing in HMC, but it exceeded the level of peNDF_>8 in the range of 21.49 to 22.53% for 50 min mixing in HMUC. However, ruminal in situ DM degradation appeared as LMUC > HMUC > HMC. Therefore, these results suggest that the rice straw silage may be useful for high-yielding lactating cows, if it can be supplied with the adequate peNDF, and the limiting factor on DMI and DM degradation was reduced by crushing of the plant tissue, although the rice straw silage was concerned to low quality forage.

Key Words

Rice straw silage, Particle size, Laceration, Physically effective fiber, Dairy cattle

박진규 Jin-kyu Park , 조병철 Byung-chul Cho , 김인희 In-hee Kim , 김경 Kyung Kim , 이남훈 Nam-hoon Lee

DOI:10.9786/kswm.2015.32.7.705

Abstract

The objective of this paper is to assess the applicability of heat recovery at aerobic landfill as a geothermal heat source. This paper presents a case study of installing gas source heat recovery system at an aerobic landfill to collect landfill gas heat. The system consists of three subsystems, i.e., the air injection system including a biofilter, the heat pump system and the thermal storage tank. A biofilter is necessary to remove the content of harmful compounds in the gas that enters the heat pump. The field test results showed that temperature for landfill gas was increased slightly from 29 to 38℃ in the phase of aeration because of decomposition of organic carbon. The biofilter effectively treated CH₄, H₂S and NH₃ in the gas to prevent the corrosion of the heat pump. The coefficient of performance (COP) of the heat pump was 3.2, which means that 3.2 kW of heat energy could be obtained by 1 kW of electrical energy used for the heat pump. This study estimated the energy cost for the different heating systems. As a result, the heat pump can reduce the energy cost by 75% compared with kerosene and diesel. Therefore, it is concluded that aerobic landfills are a suitable resource for heat recovery.

Key Words

Landfill, Aerobic, Geothermal heat source, Heat pump, COP

강의수 Ewisoo Kang , 주문솔 Munsol Ju , 전화숙 Wha Sook Jeon , 김재영 Jae Young Kim

DOI:10.9786/kswm.2015.32.7.713

Abstract

Flood disaster generates large amounts of flood wastes and it is rarely well-treated due to the heavy amount of wastes. Therefore the prediction of flood waste generation and making a plan for appropriate treatment have been required. Targeting for Seoul city, we investigated the history of flood disasters and the number of flooded buildings, and conducted regression analysis between the number of flooded buildings and rainfall data. As a result, daily average rainfall and maximum daily rainfall showed better correlations with the number of flooded buildings than total rainfall data. As a result of verification on the official unit of flood waste generation, 1.35 ton/flooded building, it was reliable data for total Seoul city, but not for regional units (gu). Finally, using regression equation and the official unit of flood waste generation, we suggested the method to predict flood waste generation by rainfall. For more reliable prediction, it is necessary to accumulate more regional data about the number of flooded buildings, building types, and topographic conditions due to a wide regional deviation.

Key Words

Flood disaster, Waste generation prediction, Regression analysis, Seoul city

김교근 Kyeo Keun Kim

DOI:10.9786/kswm.2015.32.7.720

Abstract

A total of 15 different solid waste materials were analyzed for toxic substances such as Pb, Cd, Cu, As, Hg, Cr (VI) by the Korean standard leaching test and as total content. These wastes were also tested for corrosivity characteristics using an ionic electrode for pH and a circular steel for corrosion rate. Based on the results of the leaching test, the solid waste samples did not exceed the regulated leaching levels. Thus, the analyzed wastes may be classified and managed as general industrial waste, not hazardous waste. Four solid waste samples were greater than total content levels proposed by other previous study. In case of the corrosive property of the solid waste leachate (1 : 2.5), the highest pH of the waste sample exhibited the lowest corrosion rate of 0.065 mm/yr. However, the waste samples with low pH values exhibited a greater corrosion rate. It is difficult to determine the correlation between pH and corrosion rate of the solid waste leachate. Therefore, the testing of the solid wastes are needed to further investigate the corrosion of a glass electrode method rather than the corrosion rate measurement. In the future, other hazardous properties such as ecotoxicity should be also examined to properly manage the solid waste materials.

Key Words

Solid waste, Heavy metal, Corrosive property, Corrosion rate, pH

심성훈 Sung-hoon Shim , 정상현 Sang-hyun Jeong

DOI:10.9786/kswm.2015.32.7.728

Abstract

It is known that lowering of peak temperature of flame reduces NOx emission in combustion process. Low oxygen concentration of diluted combustion air reduces peak flame temperature, but makes flame unstable. So increasing of temperature of reactants is needed to enhance flame stability. Mixing of high temperature combustion gas with combustion air makes low oxygen concentration and increases air temperature simultaneously. Low oxygen concentration of combustion air reduces peak temperature of flame and increased air temperature makes flame stable by enhancement of combustion reaction. Special apparatus for recirculation of high temperature combustion gas should be needed, because general blower cannot be used to return the gas of almost 1,000℃. Air jet type recirculation apparatus has been developed and installed in a commercial scale of 7.2 ton/day incinerator and estimated. Oxygen concentration and temperature of air mixed with inhaled high temperature combustion gas by the apparatus are 16.24 ~ 17.78%, 384 ~ 512℃, respectively, in a steady state of incineration.

Key Words

Municipal wastes incinerator, Oxygen concentration, High temperature combustion gas recirculation, Low NOx emission.

박재성 Jae-sung Park , 김옥헌 Ok-hun Kim , 김준택 Jun-taek Kim , 여운호 Woon-ho Yeo

DOI:10.9786/kswm.2015.32.7.735

Abstract

Recently, it is a critical issue for Korea that Metropolitan Landfill site life extension was in crisis contrast for local residents and local governments. In Europe and Japan, the generation of waste and landfills were suppressed and they introduced the MBT facility in order to increase the recycling and energy recovery. In this study, the process of domestic MBT facilities were evaluated by the physical and chemical composition, calorific value and biomass content, the aerobic biodegradation of biodegradable waste by comparing and analyzing each step through the evaluation. Both organic residues and inorganic residues carbon content discharged from the MBT analysis, moisture content, calorific value of residues did not meet solid refuse fuels quality standards. While the biomass content and aerobic biodegradation higher than standard biodegradable waste landfill in Europe. Biodegradable organic residue selected from domestic solid fuel manufacturing facility is expected to be able to manage through the biomass content and biological stability analysis. Based on the results of future research it is needed to review the criteria and additional landfill energy recovery by incineration residues.

Key Words

MBT, Bio-SRF, AT4, SDM, Bio mass