Sekito T, Onoue K, Dote Y, Sakanakura H, Nakamura K
Department of Civil and Environmental Engineering, University of Miyazaki, 889-2192, 1-1 Gakuen Kibanadai Nishi, Miyazaki City, Japan,
Environ Monit Assess. 2015 Jan;187(1):4193. doi: 10.1007/s10661-014-4193-8. Epub 2014 Dec 11.
To increase the amount of accessible municipal solid waste molten slag (MSWS) for its use in aggregates such as sand, MSWS must be deemed environmentally safe. Municipal solid waste (MSW) is a heterogeneous waste source used in MSWS and varies in chemical composition. Due to its nature, there is great concern about hazardous metal contamination among users of MSWS. In this study, MSWS samples were obtained weekly for 1 year from a typical incineration ash melting facility for municipal solid waste in Japan. Variation in heavy metal contents and the leachability of MSWS were investigated using two content analysis methods and two leaching tests, respectively. There is a weak correlation between metal content and concentration, and the leachability of metals in slag could not be reduced by decreasing its metal content. No measured values of hazardous metal concentration and metal content exceed the regulation levels stipulated in Japanese Industrial Standards A5031 and A5032, respectively, thereby demonstrating that the slag can be safely utilized as road and concrete aggregates. However, metal concentrations varied widely and differed by greater than 1 order of magnitude and Pb concentrations of several MSWS samples approach the regulation level. Therefore, frequent monitoring of lead leachability of MSWS and storing MSWS for several weeks to obtain a high quality that is more homogeneous in chemical composition are demanded. This study provides fundamental information for controlling the quality of MSWS and the contributing factors for achieving a safe slag recycling system.
为了增加可用于诸如沙子等集料的城市固体废弃物熔渣（MSWS）的量，MSWS必须被视为环境安全的。城市固体废弃物（MSW）是用于MSWS的一种成分各异的废弃物来源，其化学成分各不相同。由于其性质，MSWS的使用者对有害金属污染极为关注。在本研究中，从日本一家典型的城市固体废弃物焚烧灰熔融设施中，每周采集MSWS样品，持续了1年。分别使用两种含量分析方法和两种浸出试验，研究了MSWS中重金属含量的变化及其浸出性。金属含量与浓度之间存在微弱的相关性，并且通过降低熔渣中的金属含量并不能降低金属的浸出性。有害金属浓度和金属含量的测量值分别未超过日本工业标准A5031和A5032规定的监管水平，从而表明该熔渣可安全用作道路和混凝土集料。然而，金属浓度变化很大，相差超过1个数量级，并且几个MSWS样品的铅浓度接近监管水平。因此，需要频繁监测MSWS的铅浸出性，并将MSWS储存数周以获得化学成分更均匀的高质量产品。本研究为控制MSWS的质量以及实现安全的熔渣回收系统的影响因素提供了基础信息。
