Abstract

Significance Ultrapure water is a critical foundational material in the manufacturing of semiconductor chips. Its quality directly determines the yield and performance of integrated circuits. The rapid advancements in semiconductor fabrication technology impose exceptionally stringent standards for ultrapure water purity. The diversification of feed water sources， particularly the increasing use of reclaimed water， introduces new types of persistent organic contaminants. Among these， urea has emerged as a particularly challenging component. The aim of this study is to systematically review current technologies for removing total organic carbon and trace urea from ultrapure water. This will help ensure a continuous， stable， and high standard supply of electronic grade ultrapure water to meet the escalating demands of the semiconductor industry.

Progress Conventional technologies for total organic carbon removal primarily include reverse osmosis， ion exchange resin， and ultraviolet irradiation. These form the cornerstone of mainstream ultrapure water production. These technologies operate in a synergistic， multi stage process. Reverse osmosis， typically positioned at the front end， utilizes nanoscale pores for physical sieving and employs electrostatic repulsion to remove larger organic molecules. While dual stage reverse osmosis can enhance system robustness， its efficiency is limited for small， uncharged molecules. Ion exchange resin mainly removes ionizable organic carbon through ion exchange. Its effectiveness for neutral molecules relies on weak physical adsorption by the resin matrix. Ultraviolet irradiation， especially at a wavelength of one hundred eighty five nanometers， is a critical polishing step. It decomposes residual organic matter by generating hydroxyl radicals through water photolysis， effectively degrading small molecules like methanol and isopropanol. However， the combination of these conventional processes shows minimal removal efficiency for trace urea. This inefficiency is due to urea's small molecular size， electrical neutrality， high water solubility， and chemical stability. This limitation has driven the development of specialized urea removal technologies. Biodegradation uses immobilized urease enzymes for the specific hydrolysis of urea into ammonia and carbon dioxide， offering a green solution. However， it faces challenges related to enzyme stability and cost. Physical adsorption relies on materials like activated carbons or inorganic adsorbents. Their surfaces are often modified， for example by introducing carboxyl or amino groups， to enhance urea capture via hydrogen bonding. Yet， at trace concentrations， this method faces limitations in capacity and selectivity. Among all methods， advanced oxidation processes have shown the most promising potential for efficient trace urea degradation. Techniques such as ultraviolet activated persulfate or ultraviolet combined with halogen systems generate highly reactive radicals. These radicals attack and mineralize urea in a non selective manner. Research into reaction mechanisms reveals pathways to optimize degradation rates. The efficient integration of advanced oxidation process units with existing reverse osmosis， ion exchange resin， and ultraviolet polishing steps， while managing by products like nitrate or halogenated compounds， is crucial for practical application.

Conclusions and Prospects In summary， while standard processes effectively remove most organic carbon， they fail against trace urea. Advanced oxidation processes have become the leading research focus due to their high degradation potential. Future development must center on creating integrated， low-energy， and intelligent systems. This involves optimizing process combinations， developing targeted green technologies for stubborn contaminants like urea， creating solutions for new water sources， implementing smart monitoring for stable operation， and carefully managing any new impurities introduced by these advanced methods. The overarching goal is to advance towards more sustainable and efficient ultrapure water production.

Keywords： ultrapure water； organic carbon； trace urea； advanced oxidation process； integrated process

Get Citation：Zhang Xubin， Zhong Jingxiang， Liu Shuai， et al. Advances in removal technologies of organic carbon and trace urea from ultrapure water［J］. China Powder Science and Technology， 2026， 32（5）： 1-10.

Received：2026-03-16， Revised： 2026-05-31，Online： 2026-06-18.

Funding：The research was supported by Key Research and Development Program of Shandong Province (Major Scientific and Technological Innovation Project) (Grant No. 2023CXGC010601)，Natural Science Foundation of Shandong Province (Grant No. ZR2023ZD22) and General Program of the National Natural Science Foundation of China (Grant No. 22479109).

CLC No.：TQ085+.4； TB44

Type Code：A

Serial No.：1008-5548（2026）05-0001-10