Evaluation of urea removal by persulfate with UV irradiation in an ultrapure water production system
Related Experiment Video
Updated: Jan 25, 2026

Selective Area Modification of Silicon Surface Wettability by Pulsed UV Laser Irradiation in Liquid Environment
Published on: November 9, 2015
Jeongyun Choi1, Jinwook Chung1
1R&D Center, Samsung Engineering Co. Ltd, 415-10 Woncheon-Dong, Youngtong-Gu, Suwon, Gyeonggi-Do, 443-823, Republic of Korea.
Abstract:
The removal of urea by persulfate with UV irradiation in an ultrapure water (UPW) production system was examined using a continuously operated column reactor. Urea is a substance that is not properly removed by the unit processes in UPW production systems. Based on our monitoring of urea concentration over 1 year of the operation of a UPW production facility, a relatively high concentration of urea was introduced between February and May in 2016 and the total organic carbon (TOC) concentration of the UPW was increased in that period. Approximately 50% of the urea in the raw water was removed by the UPW production process, for which double-pass reverse osmosis units were instrumental. The addition of persulfate to the TOC reduction UV unit in the UPW production process was examined to improve the efficiency of urea removal. As a result, supplying over 20 μmol/L persulfate to the TOC reduction UV reactor improved the efficiency of urea removal from 9% to 90%. UV dose was an important factor of urea removal. In the ion analysis, nitrate and sulfate were detected in the effluent, and the ratio of produced nitrate to the removed urea was approximately 2.
More Related Videos
05:34Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes
Published on: December 16, 2019
06:35Implementation of a Hyperbolic Vortex Plasma Reactor for the Removal of Micropollutants in Water
Published on: July 25, 2025
Related Concept Videos
Solubility Equilibria: Ionic Product of Water
The ionic product of water varies with temperature, and its value is 1.0 x 10−14 at standard experimental conditions. Per Le...
Urea Cycle
UV–Vis Spectrum
The UV–Vis spectrum of a molecule is the plot of its absorbance versus wavelength. The plot is drawn by taking molar...
UV–Vis Spectrometers
States of Water
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
Water and Mineral Acquisition