The purpose of this study was to analyze the physicochemical characteristics of bottom-ash recycling from municipal solid waste incineration (MSWI) and investigate the possibility of the use of bottom ash for Lightweight Aggregate for Structural Concrete and Bottom Ash Aggregate for Road Construction according to Korean Industrial Standards (KS). Samples were taken from the MSWI bottom ash collected at the resource recovery facilities “A” and “B.” In the results, both samples did not satisfy the criteria of the particle sizes. In particular, the two samples failed to comply with the physical and chemical characteristics criteria of the Lightweight Aggregate for Structural Concrete. On the other hand, both bottom ash samples met the physical characteristics criteria of the Bottom Ash for Road Construction. Therefore, the recycling of Bottom Ash Aggregate for Road Construction can be more a suitable method for recycling, provided that proper pre-treatment as a screening process for bottom ash is performed.

Mechanical Biological Treatment (MBT), widely spread in Europe, is a process combined with mechanical separation and biological treatment. This is an alternative technology that can accomplish WtE (Waste-to-Energy) and landfill diversion. Bio-drying, aimed to produce high quality SRF, focused on removing moisture of waste through generated heat when biodegradable organic material is partially degraded by micro-organism. However, most of SRF production facilities in Korea consist of mechanical treatment. In those, 40% of input waste have been generated as residue disposed of in landfill. As a result of physico-chemical characteristic analysis of residue from target facilities, composition of food wastes, papers and plastics ranged 6.7 ~ 18.3%, 9.1 ~ 17.3%, and 5.8 ~ 12.2%, respectively. The moisture content of residue was about 43%, and low heating value was analyzed a range of 1,300 up to 1,900 kcal/kg. Results showed that combustible material having potential to produce SRF is discarded and the amount of biodegradable material such as food waste is still large. Therefore, we assumed it may cause pollution in terms of landfill gas emission and high concentrated leachate generation. In this study, recent trends of Bio-drying is discussed as the alternative technology to solve problems at SRF production facilities in South Korea.

각종 산업공정 및 생활과정에서 발생되는 폐기물을 처리하는 방법에는 다양한 방법이 존재하나 화석연료를 대체할 신재생에너지의 필요성이 확대되면서 폐기물도 처리되어야 할 대상에서 에너지원으로 다양한 활용방법이 제안되고 있다. 생활폐기물 고형연료제품 제조시설을 비롯한 전처리가 필요한 시설에서 중요한 것은 반입대상 폐기물의 물성이다. 본 연구는 전라남도 Y시의 생활폐기물의 물리화학적 특성을 파악하여 전처리 시설의 최적 설계 및 운영의 효율성을 증대시키기 위한 기초자료를 제공하고자 실시하였다. Y시 소각장 반입폐기물에 대한 물리적 성상조사는 폐기물 수집운반차량에 적재되어있는 폐기물 전량을 대상으로 실시하였다. 폐기물 전량을 방수포 위에 쏟아 부은 뒤에 4가지 기준(조대폐기물, 종량제봉투, 비종량제봉투, 파봉폐기물으로 분류하였다. 조대폐기물은 선별공정에 투입되었을 때 문제가 생길 수 있을 것으로 판단되는 500mm 이상 크기로 구분하고 폐기물을 분류한 뒤에 종량제 봉투와 비종량제 봉투를 구분하였다. 비종량제봉투는 일반비닐봉투나 마대자루등으로 밀봉되어 반입된 폐기물이며 파봉폐기물은 수집운반차량에서 조대폐기물 및 밀봉된 폐기물을 제외한 파봉된 상태로 수집된 폐기물로 구분하였다. 조사대상 폐기물의 수거지역은 공동주택지역(가-지역, 나-지역), 단독주택지역, 시외곽지역 및 재활용선별장(재활용 선별하고 남은 잔재물)으로 선정하였다. 반입되는 폐기물은 종량제폐기물이 22.07 wt%, 비종량제폐기물은 23.99 wt%, 파봉폐기물이 44.39 wt%, 조대폐기물의 발생량이 9.55 wt%로 확인되었다. 반입되는 폐기물 중 전처리 시설을 가동할 때 조대폐기물을 제거한다고 가정하여 조대폐기물을 제외한 시료를 대상으로 물리적 조성을 분석하였다. 분석 결과 가연성 물질은 85.66 wt%이고 그 중 비닐이 21.77 wt%로 가장 높게 나타났으며 음식물(18.14 wt%), 종이(17.47 wt%), 기저귀/생리대(6.83 wt%)순으로 발생 되었다. 삼성분 분석을 실시한 결과 평균 수분은 36.01wt%이며 폐기물의 습기준 저위발열량은 2,573kcal/kg으로 다소 낮은 것으로 확인되었는데, 이는 대상폐기물 중 수분함량이 높은 음식물의 양이 많아 발열량에 영향을 미친 것으로 판단된다.

This research performed physico-chemical analysis of MSW(municipal solid waste) for design and operation ofgasification generation system. The MSW sample was analyzed by proximate, ultimate, heat value method and sampledeach residential type classified apartment, house, urban and rural in by seasonal generation According to statistics of 2010MSW generation in Korea, On average, Namwon generated about 101.4 ton of trash and recycled almost 57.5 ton ofthis material per day, equivalent to a 56.7 percent recycling rate. It was recycled 0.73 kilograms out of individual wastegeneration of 1.29 kilograms per person per day. In 2011, On average, Namwon generated about 46.7 ton without recycledmaterial per day, and individual generation was 0.60 kilograms. It was virtually identical with statistics data in 2010. Inthe physico-chemical analysis results, it was composed of 84.1 percent of combustible and 15.9 percent of Non-combustible. On average, heat value was 2,529kcal per kilogram in condition of LHV and wet. The MSW sample wasincluded 32.0 percent of moisture, 21.9 percent of ash, 26.8 percent of carbon, 14.4 percent of oxygen, 3.7 percent ofhydrogen and 1.3 percent of others. Estimate of technical potential energy of MSW was 1,278 toe per year, equivalentto a 33.3 percent of total potential energy.