超纯水系统出现TOC季节性波动的原因与对策

Reasons and Countermeasures for TOC Seasonal Fluctuation in UPW System

针对上海地区的超纯水(UPW)制备系统在冬、春季出现TOC超标的问题,通过水质分析和检测仪器的诊断,推断原水中二乙基氨基化合物、尿素等有机物含量高,是导致超纯水系统的TOC出现季节性波动的主要原因。而现有UPW系统中的活性炭吸附、反渗透(RO)、低压紫外线氧化等工艺对这些小分子有机物去除效果并不理想。在RO后增设臭氧/NaBr的高级氧化单元,利用生成的次溴酸钠来分解这些低分子有机物,可以有效地控制UPW产品水的TOC出现季节性波动。

The UPW system has experienced violation of TOC limit in winter and spring in Shanghai area. Based on water quality analysis and apparatus testing, it is concluded that the increase in content of diethyl amino compounds, urea and other organic matters in raw water is the main cause resulting in TOC seasonal fluctuation in UPW system. These small molecule organic matters are very difficult to be removed by AC adsorption, RO, low-pressure ultraviolet oxidation and other processes. O3/NaBr advanced oxidation unit added after RO, in which the formed sodium hypobromite is used to decompose the small molecule organic matters, can effectively control the TOC seasonal fluctuation.