Overview

Electrodeionization (EDI) is an essential process step in the removal of pollutants in numerous semiconductor ultrapure water (UPW) systems worldwide. EDI technology utilizes ion exchange (IX) resin, ion permeable membrane, and high potential to continuously remove ion pollutants from ultrapure water, while regenerating usable resin in the EDI module. Real time online monitoring of effluent can ensure the quality of ultrapure water, correctly control EDI voltage, and maximize factory operational efficiency. Applying voltage in the EDI module generates a polar electric field, allowing ions to pass through the exchange resin layer and ion permeable membrane. In the ion exchange layer of the EDI module, the resin captures ions, producing ion free ultrapure water, while the potential continuously regenerates usable resin. Therefore, EDI systems require a large amount of electrical energy in daily operation.

Real time monitoring of EDI effluent

When studying the performance of EDI, we used precise online process monitoring instruments to characterize in real-time the effects of different settings of EDI power on the boron, silicon, and conductivity values in EDI effluent. Research has found that higher power settings can more effectively remove boron and silicon. However, due to the fact that EDI voltage promotes the formation of dissolved carbon dioxide in ionic form, EDI voltage increases the net conductivity value of ultrapure water.

Excessive EDI power not only increases energy costs, but also reduces the quality of ultrapure water. Therefore, determining the optimal power setting for the EDI system is crucial for ensuring the quality of ultrapure water and reducing factory operating costs.

Overall, the quality of EDI effluent depends on the quality of water supply, resin efficiency, and EDI power. As time goes by, the pollutant content and resin efficiency in the feedwater will change, so only optimal control of EDI power can maintain process performance and water quality stability. In order to correctly control the EDI power setting, it is crucial to monitor the pollutants in the EDI effluent, which can help users achieve optimal benefits in terms of energy consumption and operating costs.

In this study, semiconductor factories continuously monitored the dynamic boron concentration in EDI effluent using Sievers online ultrapure water (UPW) boron analyzer to track the concentration of key pollutants and overall ultrapure water quality. Monitoring data shows that EDI power is positively correlated with water purity, and it takes a week or more for pollutant concentration to stabilize after voltage changes. The semiconductor factory has controlled the removal efficiency of pollutants and continuously adjusted the EDI power through real-time online monitoring, minimizing the energy consumption of factory operations.

Sievers Boron Ultra Online Ultra Pure Water (UPW) Boron Analyzer

The Sievers Boron Ultra online ultrapure water boron analyzer is currently the most important basic equipment for ultrapure water quality management. This analyzer provides real-time detection function to help production plants proactively manage ion exchange processes, prevent ion pollution incidents, protect downstream processes, and increase product output. This analyzer adopts advanced technology to help users make more accurate process decisions, ensuring optimal water quality and process efficiency.