Automated total-chlorine sensing system using UV photolysis and selective nanocomposite electrode

Overview

This innovation addresses a critical need in water quality monitoring through an automated total-chlorine sensing system. The solution combines a UV photolytic process with a novel electrochemical sensor to measure total chlorine in water. By first exposing water to a UV light pulse to convert combined chlorine into free chlorine, the system can then accurately quantify total chlorine using a uniquely selective electrode. This approach eliminates common problems found in existing chlorine sensors, such as cross-interference with other oxidants and electrode fouling.

The technology targets applications in water treatment facilities, industrial process monitoring, and environmental compliance, where reliable and continuous chlorine measurement is essential for public health and regulatory adherence.

Technical specifications

The sensing system operates through two integrated stages:

• UV photolysis stage: A UV light pulse degrades combined chlorine species into free chlorine (OCl- and HOCl), enabling total chlorine measurement.
• Electrochemical sensor: A stable nanocomposite electrode formed by modifying a carbon-based nanomaterial with a free-chlorine-selective nanomaterial. The sensor detects free chlorine through electroadsorption and redox reactions, producing a measurable current via voltammetric methods.

Key features:

• Unique selectivity for free chlorine with no cross-interference from other oxidants
• Resistance to fouling, ensuring long-term reliability
• Reversible detection: potential reversal allows electrode regeneration for repeated measurements
• Designed for in-line, continuous monitoring applications
• Computational modeling to further optimize sensor performance

Technology readiness level

The concept is novel and has not been validated as a complete system. However, individual components have been supported by existing literature and preliminary measurements using property-tuned carbon-based electrodes. Current validation efforts include electrode modification with selective nanomaterials, computational optimization studies, and extensive testing with water samples containing free chlorine and chloramines under UV exposure. The next milestone involves building and testing a functional in-line sensing unit. The technology is at an early-to-mid stage of development, with ongoing research focused on demonstrating full-system performance.