Metal-organic framework technology for chloramine capture and degradation in water treatment

Overview

Chloramine is widely used as a disinfectant in municipal drinking water systems, but it is difficult to remove and poses challenges for water utilities, industrial users, and downstream treatment processes. This research proposes a new approach that uses metal-organic frameworks (MOFs) to selectively capture chloramine from water and promote its degradation within the framework itself. MOFs are porous crystalline materials with surface areas that can reach up to 6,000 square meters per gram, making them exceptionally effective at interacting with small molecules. By engineering the pore environment with functional groups such as amines, alcohols, and hydrocarbons, the team aims to create a localized high-pH environment that accelerates chloramine breakdown without raising the bulk pH of the treated water.

The solution addresses a real-world pain point: conventional chloramine removal methods are slow or require adding strong bases, which is impractical for drinking water applications. A MOF-based adsorbent could be deployed in point-of-use filters, household water purification devices, or municipal treatment facilities, offering a drop-in upgrade for existing water treatment infrastructure.

Technical specifications

Core technology:

• Metal-organic frameworks (MOFs) are porous, crystalline materials built from metal nodes connected by organic linkers
• Extremely high surface areas (up to 6,000 m²/g) enable high capture capacity for small molecules like chloramine
• Pore chemistry is tunable through post-synthetic modification with functional groups such as amines, alcohols, and hydrocarbons

Design approach:

• Functional groups inside the MOF pores create a localized pH increase, accelerating chloramine decomposition
• The approach avoids adding bulk base to the water, preserving drinkability
• Initial screening will evaluate five candidate MOFs: PCN-250, UiO-66, Mg-MOF-74, PCN-222, and MIL-125-NH2
• Downstream work will design an optimized MOF combining the most active degradation units with high aqueous stability
• Planned validation includes total adsorption capacity testing and long-term cycling studies to assess reusability

Relevant prior expertise from the research group:

• Aqueous capture of metal cations using MOFs
• Tuning hierarchical porosity for organic dye adsorption
• Tandem catalysis within catalytically active MOFs

Technology readiness level

This project is at an early research stage (TRL 2–3). No preliminary data exists yet for chloramine capture or degradation using MOFs. The proposed work begins with a systematic screen of five well-characterized MOFs to establish baseline adsorption capacities and identify any degradation byproducts. Based on these results, a purpose-built MOF will be designed and optimized for aqueous stability and degradation activity, followed by total capacity measurements and cycled-use durability testing. The research group has transferable expertise in MOF synthesis, aqueous adsorption, and catalytic functionalization, which supports feasibility but does not yet constitute validated performance for chloramine-specific applications.