Comprehensive evaluation of a pilot-scale semiconductor wastewater reuse process using ultrafiltration and two-stage reverse osmosis for securing intake water resource in ultrapure water production

The increasing demand for ultrapure water (UPW) in semiconductor manufacturing has raised concerns regarding industrial water scarcity, necessitating advanced wastewater reuse strategies. However, the complex composition of semiconductor wastewater presents challenges for conventional treatment technologies. In this study, a pilot-scale semiconductor wastewater reuse system integrating ultrafiltration (UF) and two-stage reverse osmosis (RO) was designed to achieve >75 % recovery while removing key contaminants, including low molecular weight (MW) dissolved organic matter (DOM), urea, tetramethylammonium hydroxide (TMAH), per - and poly-fluoroalkyl substances (PFAS), and SiO 2 . Most DOMs were removed, achieving 0.5 mgC/L, meeting the UPW intake water quality standards; however, small amounts of protein-like low-MW neutral substances (e.g., urea) and metal-humic complexes with Cr 2+ and Ni 2+ persisted. Lab-scale UPW production using the total RO permeate consistently yielded ≥18.2 MΩ·cm resistivity and < 1 ppb dissolved organic carbon (DOC), confirming its suitability as a reliable intake source. Economic analysis indicated that although UF and 2-stage RO involve capital (CAPEX) and operational expenditure (OPEX) costs, they remain strategically viable solutions to ensure a stable, high-quality water supply in semiconductor manufacturing. These findings establish a technical and economic framework for high-recovery membrane treatment and cost-efficient UPW production, underscoring the need for enhanced treatment strategies to address global water constraints and sustain the reliability of semiconductor supply chains. • Pilot system treats semiconductor wastewater to meet UPW intake water quality. • Intermittent 2nd-stage RO enhances recovery while mitigating membrane fouling. • >75 % recovery achieved with 0.5 mgC/L DOC, suitable for UPW intake water. • Ensuring UPW intake quality requires addressing urea and metal-humic complexes. • UPW from RO permeate achieved 18.2 MΩ·cm resistivity and < 1 ppb DOC.