I-Corps: Water Hardness Sensor

点击翻译按钮获取中文摘要

The broader impact/commercial potential of this I-Corps project will lead to the adoption of a low cost, accurate, water hardness sensor that will drive a substantial reduction in the amount of salt released into municipal sewer systems as well as reducing water waste. Softeners are regenerated with sodium chloride brine, which is usually discarded into the sewer and causes excess salinity in rivers. Some communities have restricted or banned water softeners because of this brine discharge. The incorporation of a hardness sensor on the water softener?s treated outlet would allow for complete utilization of the water softener?s capacity. Additionally, the sensor would provide a visual indication of the water softener performance. The sensor is more robust, less complex and less expensive than any other hardness sensor reported in the patent or technical literature.This I-Corps project will advance the state of the art of water softening by providing a means of detecting precisely when a salt-regenerated water softener needs regeneration. The hardness sensor detects hardness ions (e.g. calcium) by detection of a change in electrical resistance of an elongated cation-exchange material (membrane or fiber), in contact with water. The first sensors used a membrane between two plates. The newer sensors use cation exchange fibers, which provide substantially faster response. The new hardness sensor offers major advantages over the existing hardness probes available in the market. The sensor will be able to optimize softener operation, which will ensure soft water is being provided while also minimizing the environmental impact. While the immediate impact of the hardness sensor is a novel way of detecting when a water softener needs regeneration, the sensor design is expected to have applications beyond hardness monitoring. For example, the sensor can be modified to be employed in nitrate removal systems.