Flow-through membrane electrode technology for single-pass chloramine reduction in water treatment

Overview

This solution addresses chloramine removal in drinking water through flow-through membrane/electrode technology designed for efficient single-pass treatment. Chloramines are widely used as secondary disinfectants in municipal water systems, but their persistence creates challenges for point-of-use applications, industrial processes, and sensitive analytical or manufacturing operations. The technology leverages sub-micron porous conductive membranes that serve dual functions as both filtration media and electrodes, dramatically shortening the diffusion pathway between target contaminants and the electrode surface to overcome traditional mass-transfer limitations in electrochemical water treatment.

The approach offers a compelling alternative to conventional chloramine removal methods such as activated carbon adsorption or chemical reduction, which often require frequent media replacement, generate waste, or introduce additional chemicals. By operating at reduction potentials below those that trigger water electrolysis or chlorine evolution, the system maintains stable pH and prevents mineral carbonate fouling on electrode surfaces, supporting long-term operational reliability.

Technical specifications

Core technology:

• Flow-through membrane/electrodes composed of percolating networks of carbon nanotubes or sintered Ti4O7 (sub-oxide titanium) nanoparticles
• Sub-micron pore architecture that confines reactants near the electrode surface
• Electrically conducting membrane structure that functions simultaneously as electrode and flow-through medium

Key performance features:

• Target output: chloramine concentration reduced to below 0.1 mg/L in a single pass
• Degradation products limited to chloride and ammonium, with no harmful byproducts
• Stable pH operation avoiding mineral carbonate scaling on electrode surfaces
• Dimensional stability under continuous chloramine-reducing conditions
• Demonstrated continuous operation at pilot scale over months-long periods

Prior validation:

• Effective electrochemical reduction of heavy metals
• Organic contaminant oxidation capability
• Multiple electrochemical transformations demonstrated across varying pore sizes and compositions

Technology readiness level

The technology has advanced beyond initial proof-of-concept, with membrane/electrode materials previously demonstrated at pilot scale for months-long continuous operation across multiple electrochemical applications. Current research is focused on optimizing the system specifically for chloramine reduction, including fabrication and characterization of membrane/electrodes across pore size, porosity, thickness, permeability, and electrochemical property variables. Ongoing validation includes evaluating chloramine reduction performance under varying electrochemical and flow conditions, identifying degradation products, and constructing a continuous-flow demonstration system targeting 200 ml/min throughput using Los Angeles tap water. The technology is positioned for collaborative development toward commercial water treatment deployment.