화석연료의 고갈로 인한 고유가 상황과 온실가스에 의한 지구온난화가 가시화 되면서 재생 가능한 에너지개발과 자원의 효과적인 이용을 통한 자원순환사회 구축, 나아가 친환경적인 사회구현이라는 목표를 달성하기 위하여 선진국을 중심으로 환경과 에너지 문제를 해결하기 위한 연구가 진행되어 왔다. 이러한 전망을 토대로 국가적 부담을 최소화하고 실리를 추구할 수 있는 적극적이고 능동적인 대처방안을 강구할 필요성이 절실한 시점이다. 최근 신재생에너지의 확충과 기후변화 협약에 대한 적극적인 대응이 요구됨에 따라 단순 매립되던 폐기물을 에너지로 전환하여 처리하는 방식이 각광받으며 정부 계획 하에 적극적으로 추진되고 있다. 이러한 대응의 일환으로 1990년대 후반에는 유렵을 중심으로 연성에너지 체제에 부합하면서 지방자치단체 지역 공동체, 지역 주민들의 에너지 생산 활동 참여를 중시하는 지역에너지 체제가 대안으로 제시되었다. 에너지자립마을은 화석연료에 대한 의존도가 낮으며 지속가능한 마을과 유사한 것으로, 환경문제와 미래에너지 문제를 함께 고려한 개념으로 마을에서 발생되는 자원을 최대한 이용하고, 그 자원을 순환시키는 마을로 이해될 수 있다. 국내에서는 2009년부터 농림수산식품부, 환경부, 지식경제부 등 정부부처가 합동으로 각종 바이오매스를 이용하여 에너지 자립형 마을 시범사업을 추진하면서 축산 바이오매스를 이용하는 바이오가스화 기술은 농촌 지역에 도입할 수 있는 가장 실행 가능한 기술로 평가받고 있다. 본 연구에서는 농촌형 에너지자립마을에서 발생될 수 있는 다양한 유기성폐기물을 대상으로 혼합 원료의 특성과 병합 혐기성소화의 효율을 평가하기 위하여 biochemical methane potential test(BMP test)를 진행하였다. 또한, 본 연구를 바탕으로 혐기성소화와 C/N비의 관계를 알아보고자 하였다.
Mercury distribution and hazardous characteristics of major components from SCFLs (Spent compact fluorescent lamps)for 3 lamp manufactures (A, B, C) are estimated by the analysis of mercury concentration and leaching tests such asKorean Extraction Test (KET) and Toxicity Characteristic Leaching Procedure (TCLP). SCFLs can be separated into glasstube, phosphor powder, metals, ballast, plastics, and binder. Through the analysis of mercury in major components forSCFL, mercury concentration in phosphor powder is much higher than that in other components regardless manufacturesof lamp. Also, mercury concentration in phosphor powder is dependent of the manufactures of lamp. From the leachingtests, all components except phosphor powder from 3 lamp manufactures are verified to be non-hazardous waste becauseall leaching concentrations are below the regulatory level. However, the leaching concentration of mercury in phosphorpowder of SCFLs is higher than the regulatory level in both KET and TCLP regardless manufactures of lamp. Hence,phosphor powder should be managed as a hazardous waste and should be separately managed to control mercury.
Compact fluorescent lamps are strongly encouraged to manage separately in Korea because Compact fluorescent lamps contain mercury. Compact fluorescent lamps have managed as household waste in Korea, however, even though Compact fluorescent lamps contains hazardous material such as mercury. The aim of management of Compact fluorescent lamps separately is to reduce the release of mercury from Compact fluorescent lamp lamps into the environment and to reuse of the glass, metals and other components of Compact fluorescent lamps. The amount of mercury in a fluorescent lamps varies, depending on the type of lamp and manufacturer, but typically ranges between 5 milligrams and 30 milligrams. The mercury content of fluorescent lamps has been reported to be between 0.72 and 115 mg/lamp with an average mercury content of about 30 mg/lamp in 1994. Although manufacturers have greatly reduced the amount of mercury used in fluorescent lamps over the past 20years, mercury is an essential component to fluorescent lamps and can’t be eliminated completely in lamps. In the crushing process, CFL(compact fluorescent lamp) is separated into glass, plastic, ballast, phosphor powder and vapor. Using the crushing technique, concentration of mercury vapor emission from CFL is evaluated. Through the experiments, the efficiency of the crushing and separation for the unit is estimated by measuring the volume of CFL. In this study, the concentration of mercury is analyzed by MVI(Mercury Vapor Indicator) method for vapor in CFL. From the results of mercury distribution for 3 companies, the concentration of mercury in compact fluorescent lamp is less than that in the other type lamps. And phosphor powder has greater than 99% of total mercury amount in CFL and the mercury concentration in phosphor powder is measured between 1,008ppm and 1,349ppm. The mercury concentration in phosphor powder can be changed by the type of company and period of usage. KET and TCLP are carried out for phosphor powder, glass, plastic, ballast and base cap to estimate the hazardous characteristic. From the results of KET and TCLP test for CFL, phosphor powder from CFL 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. From the results of characteristics of CFL, the carbonization system of CFL should be carried out in the temperature of less than 350℃. The amount of mercury in a fluorescent lamps varies, depending on the type of lamp and manufacturer, but typically ranges between 5 milligrams and 30 milligrams. The mercury content of Compact fluorescent lamps has been reported to be between 0.72 and 115 mg/lamp with an average mercury content of about 30 mg/lamp in 1994. Although manufacturers have greatly reduced the amount of mercury used in fluorescent lamps over the past 20years, mercury is an essential component to fluorescent lamps and can’t be eliminated completely in lamps. In Korea, demonstration for recycling of U type lamps had once begun in the area of Seoul Metropolitan, 2000. In 2004, U type lamps was included as an item in EPR(Extended Producer Responsibility) system. According to Korea Lighting Recycling Association, approximately 38 million Compact fluorescent lamps were recycled in Korea, 2011 because 3 recycling facilities for Compact fluorescent lamps are operated in Korea. Recycling rate of Compact fluorescent lamps in Korea is about 31.0% but about 70% of Compact fluorescent lamps may not manage properly. Hence, discarded lamps release approximately 2 to 3 tons of mercury per year into the environment[6]. In USA, Compact fluorescent lamps has controlled by Universal Waste Rule and merchandises containing mercury prohibited to produce. Also, MEBA(Mercury Export Ban Act) is activated in USA from 2013. According to Association of Lighting and Mercury Recycler, member companies accomplish about 85% of the lamp recycling done each year. In Germany, best available technology (BAT) system for recycling of Compact fluorescent lamps is established and about 20 companies are involved in recycling of Compact fluorescent lamps. In 1994, approximately 70-80% of total Compact fluorescent lamps are recycled in 1994 and Compact fluorescent lamps was included as an item in EPR(Extended Producer Responsibility) system in 1996. In Sweden, MRT System, which was developed by Lumalampan, separated mercury from Compact fluorescent lamps by distillation operation, 1979. Reverse route collection system is active to improve the collection of Compact fluorescent lamps. Compact fluorescent lamps was included as an item in EPR(Extended Producer Responsibility) system in 2001. In Austria, about 40 companies are involved in recycling of Compact fluorescent lamps to recycle glass and ferrous metals. And wastes containing mercury are treated in landfill site by using special container [7,8]. In this study, Compact fluorescent lamps is cut by a end-cutting unit with a cam crusher and base-cap is separated from glass part. In the end-cutting unit, a vacuum system is operating to collect mercury vapor to prevent leaking from the end-cutting unit. First of all, characteristics and major composition of Compact fluorescent lamps are estimated. Through the experiments, it is measured mercury concentration in the parts of Compact fluorescent lamps such as glass tube, phosphor powder, and base cap after separation in the end-cutting unit. Also, it is evaluated mercury emission from Compact fluorescent lamps by measuring the concentration of effluent gas in the end-cutting unit with changing flow rate. Finally, Korea Extraction Method (KET) and TCLP(Toxicity Characteristic Leaching Procedure) test are applied to phosphor powder to verify that phosphor powder is a hazardous waste [9].
The estimated that 114 million units of fluorescent lamp are sold every year, and that 70% or more spent fluorescent lamps (SFLs) are generated at business sites. According to Korea Lighting Recycling Corporation, recycled amount of SFLs selected as EPR (Extended Producer Responsibility) items from 2004 has been improved from 35,250,000 units in 2010 to 37,950,000 units in 2011, which recorded the greatest amount. Based on the year 2011, SFLs have been recycled by 31.5%, but their recycled rate is insufficient yet, compared to the recycling rate of metal cans or glass bottles, which are about 80%. The base cap of SFLs as a raw material was used in this experiment. Base cap contains an insulation sieve plate, aluminum cap, copper terminal, tempered glass, filament, and copper/iron mixed wire that goes through this glass. In order to protect a filament that is made up of tungsten for the electricity to flow, circular plate consisted of iron encloses the filament. Separating apparatus of SFL base cap used in this experiment is a device which has used impact crushing technique using hammer, screen separation and magnetic separation for the purpose of recovering aluminum, copper and iron contained in SFL. Impact hammer crusher, a device that separates aluminum from other materials by hammer impaction on the base cap that is separated by end-cutting, causes a significant reduction for other materials to be included in the collectible materials by separating aluminum, copper and iron from the base cap by using hammer crusher at 3 stages. Iron was collected by using a magnetic separation unit and the collectible materials were separated into aluminum with larger particles, and glass and other materials with smaller particles by screen separation. The separation performance was estimated for the 3 stages of hammer crusher unit to recover aluminum from the base-cap of SFLs and the separation performances are 94% at the 1st stage, 97% at the 2nd stage, and 98% at the 3rd stage, respectively.
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.