This Small Business Innovation Research Program (SBIR) Phase I project is aimed at development of a conductometric cell for water quality monitoring that employs properties of polyxoxmetalats (POMs) and their so called lacunary derivatives. The proposed approach is based on measurements of electric conductivities of solutions of lacunary POMs and water samples under investigation before and after mixing in the conductometric cell consisting of two chambers. The lacunary POMs are very soluble in water and highly charged anions capable of incorporation of multi-valent cations, such as Ca2+ and Mg2+, which are primarily responsible for total water hardness. Changes in solutions' conductivities due to the encapsulation of these cations into lacunary POMs will be used for their quantitative determination in water samples. Research objectives of this project will include development of the conductometric monitor and semi-empirical calibration models for determination of water hardness. Performance of the cell will be compared with potentiometric and colorimetric techniques currently used on the market for water hardness determination. The anticipated technical results of this research will lead to implementation of this technology to produce a series of water hardness monitors ranging from portable instruments to in-line industrial grade monitoring systems. The broader impact/commercial potential of the proposed innovation relates to application of this instrumentation to reliable water analysis. This research project will enhance better understanding of encapsulation of multi-valent cations into lacunary POMs under moderate conditions and its effect on electric conductivities. The main area of application of the proposed approach is in water quality control and environmental monitoring. Development of this technology will be beneficial for water distribution and monitoring infrastructure. It will be of interest to a wide spectrum of customers: municipal facilities, beverage producers, hospitals, hotels, laundry facilities, and industrial plants. Water hardness creates a variety of problems negatively affecting efficiency of heat transfer and water distribution systems, and inexpensive and reliable in-line instrumentation is of great demand on the market. The most prospective application of this monitor is anticipated to be in advanced municipal water treatment. In the United States, this market is growing at a compound annual growth rate of 8.2% to reach $2 billion in 2016. POMs are very diverse, and their lacunary forms are capable of incorporation of various cations. If proven successful, this approach can be extended to monitoring of other species and toxic pollutants in drinking water or wastewater
