Silver Biocide Analysis & Control Device

Rapid, accurate measurement and process control of silver ion biocide concentrations in future space missions is needed. The purpose of the Phase I program is to develop an electroanalytical device for analysis and process control of biocidal silver in potable water, with the option integrating an Ag+ ion generator. The device will automatically provide continuous and on-demand maintenance of Ag+ ion biocide levels in spacecraft water streams and storage tanks, as well as providing output data for silver concentrations and a profile of total silver added to the system over time. Considerable test work is planned under the AES program and, given silver ion's 'elusiveness' in water systems, the data will be far more reliable if the methodology for adding the biocide and measuring its concentration is performed by a reliable and flight-qualifiable design from the beginning. The Phase I Technical Objectives are to develop the device specifications, software and hardware to conform to spacecraft applications as specified by NASA. The specific objectives will be to 1) develop a complete analytical characterization of the detection method, inclusive of automated autocalibration and QA/QC functions, 2) demonstrate the Feedback Control Function to maintain consistent Ag+ ion concentration in active water systems, and 3) determine the operating parameters required to generate Ag+ in the ranges of 0.05-40 mg/l in potable water. Phase I will culminate in a complete analytical methodology and a flight preproduction prototype for measurement and control of silver ion at sub-ppb levels in finished waters.