Abstract:

Based on a 12-inch semiconductor ultrapure water pilot line, the total organic carbon (TOC) removal process and the molecular weight distribution of organic matter in the ultrapure water system were tracked and measured. The effects of irradiation intensity, hydraulic retention time, and molecular bonding energy of organic matter on the removal of typical trace organic pollutants from water were investigated in a TOC-UV unit. The results showed that the two-stage reverse osmosis (RO) system removed 98.5% of the TOC and the water producted by the first stage RO contained 97.3% neutral small molecules with molecular weights below 350 u. Within a certain range to strengthen irradiation intensity and hydraulic residence time in the TOC-UV unit could effectively improve the removal performance of small molecules of organic matter. The best TOC removal effect was achieved when the 185 nm ultraviolet lamp with an irradiation intensity of 2.46 mW/cm² was selected, and the best removal efficiency was achieved when the retention time was 40 s. The degradation effect of UV on organic matter was significantly affected by the bond energy of the organic pollutants. For low molecular organic matter with high bond energy, such as urea (728 kJ/mol), its removal rate by TOC-UV was low.

Key words: ultrapure water, TOC, TOC-UV, low molecular weight organic matter

摘要：

基于某12寸半导体超纯水中试线，对超纯水系统各处理单元总有机碳（TOC）去除过程及有机组分分子质量分布情况进行了跟踪检测，探究了有机碳紫外降解（TOC-UV）装置照射强度、水力停留时间和有机物分子键能对水中典型痕量有机污染物去除效果的影响。结果表明：两级反渗透（RO）系统可去除98.5%的TOC，一级RO产水中含有97.3%分子质量低于350 u的中性小分子物质；在一定范围内提升紫外光照射强度与水力停留时间可提升对小分子有机物的去除效果，2.46 mW/cm²的185 nm紫外灯对TOC去除效果最好，水力停留时间为40 s时TOC去除效率最佳；UV对有机物的降解效果明显受物质键能影响，TOC-UV对具有较高键能的小分子有机物（如尿素728 kJ/mol）的去除率较低。

关键词: 超纯水, 总有机碳, TOC-UV, 小分子有机物

CLC Number: 

• TQ085