对H市和L市铸铁管道管垢样品进行了采集,并利用X射线衍射分析(XRD)、全自动比表面积及微孔物理吸附仪和场发射扫描电镜(FESEM)对管垢的物理化学特征进行了表征。通过模拟试验考察了在相同水质和水力条件下,管垢特征对铁离子释放速率的影响。研究发现,两地管垢主要晶体成分为Fe3O4(磁铁矿)、α-FeOOH(针铁矿)和SiO2(石英),但每种组分所占的比例不同。H市管垢中Fe3O4所占比例小于L市管垢,而α-FeOOH所占比例大于L市管垢。H市管垢多孔,比表面积较大,L市管垢较密实,比表面积较小。铁离子释放量则表现为H市管垢大于L市管垢。
Corrosion scales from cast iron pipes in H and L cities were collected and characterized by using X-ray diffraction (XRD), accelerated surface area and porosimetry system and field emission scanning electron microscopy (FESEM). The effect of corrosion scale characteristics on iron release was investigated through simulation experiments with the same water quality parameters and hydraulic regime It was found that Fe3O4, α-FeOOH and SiO2 were the primary crystalline phases in corrosion scales from both cities hut were present in different proportions. The percentage of Fe3O4 in the two cities was H 〈 L and that of α-FeOOH was H 〉 L. Corrosion scales in H city had higher porosity and specific surface area than in L city. The concentration of iron released from corrosion scales in H city was greater than that in L city.