scholarly journals Use of Clay Minerals to Control Radioactive Cesium Leaching from Municipal Solid Waste Incineration Ash in Fukushima Prefecture in Summer and Winter

Pollutants ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 253-269
Author(s):  
Naoharu Murasawa ◽  
Tamao Hatta

Radioactive cesium (r-Cs) released from the 2011 Fukushima Daiichi Nuclear Power Plant attaches to vegetation/soil and is collected as municipal solid waste (MSW) for incineration, being concentrated in incineration ash (bottom ash [BA], fly ash [FA], and chelate-treated FA [TFA]). r-Cs in FA and TFA can easily leach upon contact with moisture. It is important to prevent further contamination, as r-Cs has negative effects on ecosystems and the human body. Naturally available clay minerals, considered effective for capturing r-Cs, are a good alternative. Here, we sampled ash from MSW incineration facilities in Fukushima in August 2016 and February 2017. We used energy dispersive X-ray fluorescence spectroscopy and Ge semiconductor detector to determine elemental composition and r-Cs concentration in the samples and conducted leaching tests. We also determined the extent of leaching suppression by zeolite, acidic clay, and vermiculite. Chloride contents and r-Cs leaching rates were higher in FA and TFA than in BA, regardless of the season. Prior direct addition and mixing of clay minerals (5 to 20 wt.%) effectively prevented r-Cs leaching. This study is the first to examine r-Cs leaching inhibition by clay mineral direct addition and mixing to MSW incineration ash.

Recycling ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 56
Author(s):  
Naoharu Murasawa

Following the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident caused by the 2011 Tōhoku earthquake and tsunami, radioactive caesium (r-Cs) was detected in the ash generated by municipal solid waste (MSW) incineration facilities in Fukushima Prefecture. This has led to concerns of r-Cs leaching and subsequent environmental contamination during recycling or landfill disposal. Therefore, it is crucial that the relevant authorities have a thorough understanding of r-Cs leaching behavior to establish suitable prevention methods. In this study, we collected r-Cs-contaminated fly and bottom ash (FA and BA) samples from five MSW incineration facilities in Fukushima Prefecture and conducted tests to clarify their basic physical properties and r-Cs leaching properties. We also examined the possibility of preventing r-Cs leaching by adding 5 wt% acid clay to the FA. FA had greater chloride content and r-Cs leaching rate than BA and was found to absorb moisture and deliquesce when stored under high-humidity conditions. However, the addition of acid clay effectively prevented r-Cs leaching upon contact with moisture. From the results, we propose some specific recommendations to counter the leaching of r-Cs from FA at MSW incineration facilities, which will limit r-Cs leaching during recycling or landfill processes.


2021 ◽  
Vol 121 ◽  
pp. 33-41
Author(s):  
Yanjun Hu ◽  
Lingqin Zhao ◽  
Yonghao Zhu ◽  
Bennong Zhang ◽  
Guixiang Hu ◽  
...  

Buildings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 179
Author(s):  
Jad Bawab ◽  
Jamal Khatib ◽  
Said Kenai ◽  
Mohammed Sonebi

Waste management is a vital environmental issue in the world today. Municipal solid wastes (MSWs) are discarded in huge quantities on a daily basis and need to be well controlled. Incineration is a common method for reducing the volume of these wastes, yet it produces ashes that require further assessment. Municipal solid waste incineration bottom ash (MSWI-BA) is the bulk byproduct of the incineration process and has the potential to be used in the construction sector. This paper offers a review of the use of MSWI-BA as aggregates in cementitious materials. With the growing demand of aggregates in cementitious materials, MSWI-BA is considered for use as a partial or full alternative. Although the physical and chemical properties of MSWI-BA are different than those of natural aggregates (NA) in terms of water absorption, density, and fineness, they can be treated by various methods to ensure suitable quality for construction purposes. These treatment methods are classified into thermal treatment, solidification and stabilization, and separation processes, where this review focuses on the techniques that reduce deficiencies limiting the use of MSWI-BA as aggregates in different ways. When replacing NA in cementitious materials, MSWI-BA causes a decrease in workability, density, and strength. Moreover, they cause an increase in water absorption, air porosity, and drying shrinkage. In general, the practicality of using MSWI-BA in cementitious materials is mainly influenced by its treatment method and the replacement level, and it is concluded that further research, especially on durability, is required before MSWI-BA can be efficiently used in the production of sustainable cementitious materials.


2011 ◽  
Vol 474-476 ◽  
pp. 1099-1102
Author(s):  
Hai Ying Zhang ◽  
Yi Zheng ◽  
Hong Tao Hu ◽  
Jing Yu Qi

Bottom ash from municipal solid waste incineration (MSWI) has been previously suggested as an adsorbent for removing heavy metals from wastewater due to its high porosity and large surface area. In this study the adsorption characteristics of heavy metals were investigated using various particle sizes of MSWI bottom ash. The adsorption experiment was conducted using synthetic wastewater containing Cu, Zn, Pb and Cd as a function of residence time, initial pH, ash dosage and particle size, respectively. The adsorption rate increased with decreasing particle size and with increasing residence time. Through the above analysis, this work proved that bottom ash was effective in adsorbing the four heavy metals.


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