Study on the Long-term Cytotoxicity of MSWI Ash Wastes and Its Application on Assessing the Washing Conditions for Ashes

• Main Authors: Hsing-Chuan Tang, 唐幸絹
• Other Authors: Wu-Jang Huang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/68841175081961849535

碩士 === 國立屏東科技大學 === 環境工程與科學系所 === 97 === The reutilization of municipal solid wastes from incineration (MSWI) ash wastes has been actively promoted by the government lately; so far the percentage in the reutilization of bottom ash reached only a 52% in 2008. If we want to reuse fly ash, we must know that fly ash provokes a pernicious effect in living organisms. Therefore in this study we use two extractants (acetic acid and DI water) in the multiple toxicity characteristic leaching procedure (MTCLP) for MSWI ash wastes, in order to obtain a long-term toxicity, and to assay the correlation between components of leachates with cytotoxicity of Vero cell. Therefore we can know how much washing time of ash wastes is needed. Acetic acid and DI water were used in this experiment with the function of extracting MSWI ash wastes. The results of cytotoxicity showed that acetic acid extracts had a higher REP% values than the ones obtained from DI water extracts. When using acetic acid as extractant, it shows that toxicity of extracts increased with the pH values and concentrations of Ca and Sr. Ash wastes have to be washed 6 days in order to obtain a non-toxic ash; when using DI water as an extractant, it shows that toxicity increased with concentrations of Cr due to that ash wastes have to be washed 7 days in order to have a lower toxic ash. Therefore we suggest that the water-washing of ash wastes should be done for long-term period (> 5 days) and water has to be renewed every day. In this study we have found that Sr has significant effects on the cytotoxicity of Vero cell, however, the TCLP regulation of ash wastes in Taiwan nowadays does not include Sr. Therefore we recommend that the regulation level for Sr should be less than 2.0 mg/kg.