供水管网管垢的特征及其对水质的影响研究

Characterization of Corrosion Scales in Water Distribution System and Their Effect on Water Quality

研究了饮用水供水区域内形成的两种管垢特征及其对水质的影响。SEM/EDX、XRD等分析表明,结构致密的管垢层主要晶体成分为SiO2、α-FeOOH、Fe3O4和γ-Fe2O3,结构松散易脱落的管垢层则含有大量的γ-FeOOH及少量的α-FeOOH。通过模拟试验考察了更换水源对不同特性管段出水水质的影响。结果表明,对于管垢层致密的管段,水源更换对其出水水质无明显影响,出水澄清、浊度达标;而对于管垢层疏松的管段,水源更换后腐蚀垢层与管网水质之间的平衡被打破,管段出水浑浊、浊度超标,运行一段时间后建立新的平衡,出水浊度才趋于稳定且达标。

Two types of cmrosion scales in different water distribution systems and their effect on the water quality were studied. Scanning electron microscopy, energy dispersive X-ray fluoresence spec- trometer and X-ray diffraction techniques show that SiO2 , α-FeOOH, Fe304 and γ-Fe2O3 are the primary crystallines in the compact scale layer. The main constituents of the loose scale layer are γ-FeOOH in large quantity and α-FeOOH in small quantity. The effect of the water source replacement on water quali- ty in different characteristic pipe sections was investigated through the simulation experiment. It is found that in the section with compact soale layer, the water source replacement has no significant effect on the effluent quality, the effluent is clear, and the turbidity meets the standard. However, in the section with loose scale layer, the balance between the corrosion scales and water quality is broken after the water source replacement, the effluent quality is turbid, and the turbidity exceeds the standard. The effluent turbidity meets the standard when the new balance is built after a period of operation.