再生水氯消毒对管网腐蚀的影响

Effect of reclaimed water chlorination on pipeline corrosion

为了弄清加氯消毒后的再生水对管材的腐蚀程度,对加氯后的再生水腐蚀水泥砂浆内衬和铸铁管材的情况开展试验研究,分析硅酸盐和钙离子在试验管段中的释放浓度,结果发现再生水加氯在短时间内对水泥砂浆内衬腐蚀的影响不大。采用电镜扫描、电化学法和失重法等研究再生水对铸铁材料的腐蚀情况,从多重角度分析加氯对腐蚀速率的影响。结果表明,提高加氯量能够间接减缓再生水对铸铁材料的腐蚀速率;经过再生水加氯腐蚀后的金属表面形成了含氯的腐蚀产物。

The corrosion of reclaimed water to pipe materials is evident.However,it is unknown whether the reclaimed water chlorination would accelerate the corrosion process.Therefore,the corrosion of reclaimed water to cement mortar linings(CML)and cast iron materials after chlorination was investigated in detail.The concentrations of silicates and calcium ions released in pipes were analyzed to determine the corrosion of CML.The results showed that CML corrosion was not directly influenced by chlorination in the initial period.The scanning electron microscopy(SEM),electrochemical method,and the weight-loss method were used to investigate the influence of chlorination on the corrosion rate of cast iron materials.It was proved that increasing chlorine dosage could indirectly retard the corrosion.In addition,the corrosion products were formed on the surface of cast iron pipes after the corrosion process.