for Improved Process Performance
Aaron Dotson, UAA
Using a prototype parallel flat ceramic membrane UV system constructed during in 2013 (See Figure 7), design parameters and treatment efficacy will be determined. Low pressure UV and vacuum UV will be directly compared in simulated drinking water at varied cross flow rates (1-5 m/s), UV fluxes at membrane surface (pathlength 1.5 – 3 cm), UV transmittance (0.05 – 0.5 cm-1), and in the presence of reactive solutes (e.g. nitrate, chloride, chlorine, carbonate). The primary results of this task will be design parameters that will be carried forth to the subsequent pilot-scale system design and construction. Additionally, results regarding DBP Precursor control and pathogen inactivation will be linked to fundamental aspects of the system design. Methodology for monitoring DBP precursors and microbial pathogens described previously will be used for this task. This task and constructed bench-scale unit will provide rapid evaluation of changing test condition due to its construction with design flexibility in mind.
Using the design parameters determined in Task 1, a pilot scale system will be constructed in the UAA machine shop with custom parts from ceramic membrane and UV lamp vendor as well as custom automation using open-source hardware (e.g. arduino). The system will then undergo design confirmation in the laboratory with synthetic water and benchmarked against previous results. Rigorous evaluation will be performed to determine system stability prior to installation at a community where other piloting is on-going (in conjunction with ANTHC). The system created will be the first of its kind.
Pilot scale testing will allow for long-term testing of membrane fouling rate under dynamic influent water quality conditions, specifically seasonal changes in DBP precursors, temperature and ionic strength. Furthermore, the research team will encourage local operational assistance to identify operator challenges that may require additional training over more conventional processes.
Piloting of the proposed technology will be performed in conjunction with an on-going project in Rural Alaska lead by the Alaska Native Tribal Health Consortium (ANTHC). The technology will be piloted along side of other technologies being considered for an full-scale implementation.