基于氧化还原电位调节的管网铁释放控制特性  

Characteristics of Iron Release Control Based on Oxidation Reduction Potential Adjustment in Drinking Water Distribution System

作　　者：米子龙[1] 张晓健[1] 刘昀[1] 

机构地区：[1]清华大学环境学院,北京100084

出　　处：《中国给水排水》2015年第7期1-5,共5页China Water & Wastewater

基　　金：国家水体污染控制与治理科技重大专项(2012ZX07404-002)

摘　　要：针对水源切换引发的供水管网铁释放问题,研究了基于游离氯和氯胺调节管网水氧化还原电位(ORP)对铁释放的控制特性。研究表明,ORP≥300 m V时,氧化还原电位与游离氯具有显著正相关性,而与氯胺无相关性。采用游离氯消毒时,在低氧化还原电位(ORP≤300 m V)条件下,管壁的铁锈垢发生还原反应,铁释放随着腐蚀性阴离子浓度的升高而显著增强;在高氧化还原电位(ORP≥400 m V)条件下,管壁的铁锈垢基本稳定,离子强度的升高对铁释放基本无影响。采用氯胺消毒时,管网水的ORP<300 m V,管壁的铁锈垢易发生还原反应而引发铁释放,且离子强度越高,铁释放速率越快。可见,游离氯具有更高的氧化还原电位,对管网铁释放具有更优的控制效果。因此,当水源切换为有机物等耗氯物质含量显著降低的优质水源后,建议水厂将氯胺消毒切换为游离氯消毒。The control measures based on oxidation reduction potential （ORP） adjustment by adding chlorine and chloramine for iron release caused by water source switch in drinking water distribution system were investigated. It was found that when ORP was equal to or more than 300 mV, it had a positive relationship with free chlorine, but had no correlation with chloramine. Under the condition of chlorine disinfection, elevating the concentration of corrosive anion could accelerate the iron release if ORP was equal to or less than 300 mV, and ion strength had no effect on iron release if ORP was equal to or more than 400 mV. Under the condition of chloramine disinfection, ORP of pipe water was less than 300 mV, and iron release was increased by elevating ion strength. The free chlorine had better control effect on iron release due to its higher ORP. Thus, it was suggested that use chlorine disinfection instead of chloramine disinfection in water treatment plants when switched into high quality water source containing lower natural organic matter.

关 键 词：氧化还原电位 游离氯 氯胺 供水管网 铁释放控制 

分 类 号：TU991[建筑科学—市政工程]