探討垃圾焚化灰渣之長期細胞毒性及其於評估灰渣水洗條件之應用

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

唐幸絹(Hsing-Chuan Tang)

指導教授 ： 黃武章

國立屏東科技大學/工學院/環境工程與科學系所/碩士(2009年)

https://doi.org/10.6346/NPUST.2009.00078

摘要

現今政府積極推動垃圾焚化灰渣再利用的政策，截至目前為止底渣再利用率已達52 %，然而飛灰沒有被作為再利用之用途，若飛灰要進行再利用的話，我們也必須知道它對生物體的危害性。因此本研究將利用兩種萃取劑(冰醋酸和去離子水)，以連續式毒性特性溶出試驗(Multiple Toxicity Characteristic Leaching Procedure, MTCLP)製備垃圾焚化灰渣長期溶出液，並分析其成分對於非洲綠猴腎細胞(Vero cell)細胞毒性的關聯性，藉此評估灰渣需經過幾天的酸洗和水洗後才對生物體不具毒性，方可進行再利用。
細胞毒性結果顯示，冰醋酸萃取液的毒性較去離水的高；當以醋酸萃取時，毒性都會隨著pH值和Ca、Sr的濃度增加而增加，並且灰渣需萃取到第6天才會呈現無毒性；而以去離子水萃取時，毒性則是隨著Cr的濃度增加而增加，並且灰渣需萃取到第7天才會較無毒性，因此建議灰渣若要水洗再利用的話，應要長時間(> 5天)的漂洗，並且每天換水。
本研究還發現，Sr對於細胞毒性有顯著的影響，然而目前TCLP管制標準中Sr是不管制的，因此建議可以將Sr的濃度訂為低於2 ppm。

關鍵字

垃圾焚化灰渣 ； 非洲綠猴腎細胞 ； 細胞毒性 ； 連續式毒性特溶出試驗 ； 水洗 ； 酸洗

並列摘要

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.

並列關鍵字

MSWI ash wastes ； Vero cell ； Cytotoxicity ； MTCLP ； Water wash ； Acid wash

參考文獻

16.李志偉、李明國、孫常榮、高思懷，2007。「都市垃圾焚化底渣以水萃及磷酸穩定為資源再利用前處理程序之研究」，中華民國環境工程學會第十九屆年會暨各專門學術研討會論文摘要集，高雄，第345頁。

17.李靜如、范文彬、李正楠，2007。「焚化底渣於水洗過程中重金屬釋出之研究」，中華民國環境工程學會第十九屆年會暨各專門學術研討會論文摘要集，高雄，第392頁。

2.Brocca, D., Barilli, L., Collina, E., Lasagni, M., Tettamanti, M., and Pitea, D., 1997, “A new quantifying TOC and COD methodology for the determination of organic compounds and particulate carbon directly on fly ash of MSWI”, Chemosphere, Vol. 35, pp. 2203–2213.

4.Wiles, C. C., 1996, “Municipal solid waste combustion ash: state-of the- knowledge’’, J. Hazard. Mater., Vol. 47, pp. 325.

5.Iori, J., Balg, J. and Wieckert, C., 1995, “Detoxification of municipal waste incineration residues by vitrification’’, ABB Review, Vol. 6/7, pp. 9-16.