下水污泥混合皂土與水淬爐石堆肥化過程之重金屬型態轉變

Fraction transformation of heavy metals during co-composting of sewage sludge with bentonite and blast furnace slag

張文翰(Wen-Han Chang)

指導教授 ： 許正一

國立屏東科技大學/工學院/環境工程與科學系所/碩士(2010年)

https://doi.org/10.6346/NPUST.2010.00071

摘要

下水污泥富含有機物質，但在土地施用時有重金屬污染的疑慮。皂土與水淬爐石可吸附重金屬，與下水污泥結合後適合應用於土壤之改良。本研究將下水污泥與皂土和水淬爐石經40天堆肥化後，以序列萃取法監測重金屬型態的變化。實驗結果顯示，堆肥化過程中，重金屬型態可由不穩定的水溶態和交換態，轉變成移動性較低的有機物結合態或殘餘態。下水污泥與皂土比例為7:3時，Pb和Zn主要以鐵錳氧化物結合態的型態存在。水淬爐石吸附下水污泥中的Pb和Zn，也多以鐵錳氧化物結合態和有機物結合態為主要移動型態。堆肥化過程，發芽率在75:25(下水污泥：皂土)與70:30(下水污泥：水淬爐石)的比率較高，符合堆肥成品施用的規範。

關鍵字

下水污泥 ； 皂土 ； 水淬爐石 ； 堆肥化 ； 重金屬

並列摘要

Sewage sludge is abundant in organic matters that can be used for crop growth. The restriction of sewage sludge in land application is due to potentially contains heavy metals. Bentonite and blast furnace slag due to their strong metal adsorption capacities can be used to mix with sewage sludge to improve soil quality. The study was to use bentonite and blast furnace slag co-composted with sewage sludge in the composting process for 40 days and to evaluate the transformation of heavy metal fraction with Tessier sequential extraction. The results showed that in the composting process, heavy metal fractions transformed from water-soluble and exchangeable fraction to organic matter-bound fraction or residual fraction. When the ratio of sewage sludge and bentonite is 7:3, Pb and Zn exist mainly in Fe-Mn oxide-bound fraction. The Pb and Zn in sewage sludge adsorbed by blast furnace slag are mainly mobility fraction as Fe-Mn oxide-bound and organic matter-bound fraction. In the composting process, germination rates of 75:25 (sewage sludge: bentonite) and 70:30 (sewage sludge: blast furnace slag) are higher. The results showed application of compost products meet the specification.

並列關鍵字

sewage sludge ； bentonite ； blast furnace slag ； composting ； heavy metal

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