Application of Photochemical Processes
for the Design and Implementation of
Sustainable Treatment for Small Systems

Karl Linden, CU (Project Lead)


The overall goal of this project is to explore the applications of photochemical processes, including both sunlight and engineered light sources, to advance water quality and provide effective photon-based water treatment for small systems.

Experimental Approach

The project will be broken into 4 related activities. Activity 1 will focus on the characterization of the photochemical properties of samples collected from field sites, relating to disinfection efficiency and impacts on DBP formation. The work will focus on the design and performance verification of ponds to achieve the stated goals of inactivation and DBP precursors modification. The end product will be a set of design criteria for the development of optimized retention pounds for a specific system. Activity 2 will study and field-test a small-system sized UV (ultraviolet) LED (light emitting diode) disinfection module containing UVLEDs of varying wavelengths that will be optimized for relevant disinfection applications. Activity 3 will implement an existing bench-scale proof-of-concept for photocatalytic reduction of nitrate in ion exchange brines and complex water matrices and work to develop new photocatalysts for direct nitrate treatment of groundwater and surface water. Activity 4 will evaluate an innovative UV-Membrane hybrid process at bench-scale using a recently constructed system followed by design and construction of a pilot-scale system to be tested in the field.

Expected Results

The project will develop four innovative photon-based engineered processes using sunlight or UV-lamp systems. Design parameters for retention ponds to optimize disinfection and DBP precursor removal will be generated. The sustainability of emerging UVLED technology for disinfection will be assessed and compared to conventional UV sources for inactivation of key pathogens, indicating the promise of UVLED technology for rapid implementation into small system treatment processes. A photoreactor capable of transforming nitrate to innocuous nitrogen gas under ambient conditions, with zero-chemical addition and catalyst recovery will be produced and tested at field scale. Finally the research is expected yield a combined UV/Ceramic membrane filtration unit process that will improve overall treatment efficiency and ease operation in comparison to a similar conventional treatment trains.