蛍光X線分析用都市ごみ焼却主灰標準試料の調製と評価

摘要

今日，日本では都市ごみの発生量はやや減少傾向にあるものの，依然4千万トン以上の一般廃棄物を排出している．都市ごみの焼却で発生する焼却灰は，焼却後の燃え残りの主灰とバグフィルターなどの大気汚染防止装置で捕集した飛灰に分けられる．%Standard bottom ash for elemental analysis of trace elements was developed and evaluated. Standard ash of municipal solid waste was prepared by sieving, pulverizing and homogenizing ash sample (bottom ash; Kyushu, Japan). The concentrations of Cr, Ni, Cu, Zn, Sr, Zr, Cd, Sn, Sb and Pb in the ash standard were given with alkali fusion/atomic absorption spectrometry (AAS) or inductively coupled plasma atomic emission spectrometry (ICP-AES) analysis. The homogeneity of the ash powder was estimated by analysis of variance after Cochran test. The concentrations of 12 hazardous elements (Cl, Cr, Ni, Cu, Zn, Br, Sr, Zr, Cd, Sn, Sb, Pb) determined by X-ray fluorescence (XRF) analysis were used for analysis of variance, after validation of the quantitative results of these elements with reference materials (coal fly ash: NIST 1633b, fly ash: BCR-176R). For the determination of Cl and Br, X-ray tube power was used under 1.0 kW (50 kV-20 mA) to prevent the volatilization with X-ray irradiation. There is no significant difference between the within-bottle variance and the between-bottle variance, indicating that the ash powder was sufficiently homogenous. The concentrations determined using XRF analysis were approximately the same as those resulting from AAS or ICP-AES analysis.