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Instrumentation Sensing The Future: Water Technology's "Holy Grail" Real-time contaminant detection, featuring a network of sensors throughout the distribution network, is poised to revolutionize the water industry. wateronline.com ■ Water Online The Magazine 12 S cientists are scrambling to beat each other to the punch, and instrumentation companies are monitoring (no pun intended) the competition closely and aggressively. At stake is the inside track on a technology that promises to change the course of utility operations, and perhaps much more. The breakthrough dis covery is the real-time detection of bacteria and other constituents in water, with the added capability of instantly communicating the data to a central location. For drinking water utilities, it's the arrival of "intelligent water distribution," utilizing a network of these remote-communication, real-time sensors to detect contaminants throughout the distribution system. Though the technology is not yet mature, these sensors are most definitely coming — and their impact will be profound. A New World Of Capabilities "You can't control what you can't measure" is a broadly applicable adage (coined by software engineering guru Tom DeMarco), and particularly relevant to water quality. Imagine what the control operators would (or will) gain by being able to remotely see contaminants of any type, anywhere in the pipeline — from plant to tap — in real time. No longer would samples need to be gathered in the field and taken back to the lab for testing. When it comes to bacteria and viruses, the time lag between contamination and discovery that currently exists would be essentially eliminated, meaning less community exposure and illness. The benefits these enhanced capabilities bring to public health and utility operations are easy to recognize. But what else does real-time sensing bring to the table? The possibilities are virtually limitless. Because the sensors can be engineered on an ad hoc basis — that is, customized for specific needs and constituents — the technology has the potential to be utilized for almost any application involving liquids and to measure just about anything. The industrial and wastewater applications are further down the line, however, as the sensors are engineered to become more robust. Initially the technology will be used to detect and communicate the presence of drinking water contaminants, specifically E. coli and heavy metals (e.g. arsenic, cadmium, chromium, lead, and selenium). Research And Development As you read this, Dr. Junhong Chen is working feverishly. So, too, are his competitors. The goal is to be the first to market with this new sensor technology, and the market won't respond unless the price is reasonable. According to Chen, director of the U.S. National Science Foundation Industry- University Cooperative Research Center (I/UCRC) on Water Equipment and Policy at the University of Wisconsin-Milwaukee (UWM), that price is $10 per sensor. A second challenge is to ensure the resiliency of the units in the field, since the very idea of the technology is to "set it and forget it" (for at least a year, and then only to change the battery), thereby dispensing with the typical O&M; effort of sending personnel to multiple sampling sites. The third obstacle is miniaturization of the sensors, so that many individualized contaminant detectors can be housed in a single probe. "In the size of a fingernail, we can potentially integrate hundreds of sensors," said Chen, who described the patent-pending technology as the "Holy Grail" for the water industry. "We'll have sensors attached to the filter cartridge, to the pump, and to the water meter so that — in addition to whatever conventional functionality the equipment is providing — we can see contamination levels," Chen predicted. "That's the future." The rapidly developing technology is being realized due to the development of graphene, which earned the 2010 Nobel Prize in Physics for the University of Manchester researchers who discovered it. At just one atom thick, graphene is "not only By Kevin Westerling, editor Figure 1. Inventor Dr. Junhong Chen (right) and former student Dr. Ganhua Lu see huge potential for their small sensor. Figure 2. The incredibly shrinking sensor (miniaturization is ongoing) in comparison to a quarter. 1 2 V E R T _ 0 2 1 4 E Z i n e _ K W _ D G . i n d d 1 12VERT_0214 EZine_KW_DG.indd 1 1 / 3 1 / 2 0 1 4 1 : 0 3 : 3 8 P M 1/31/2014 1:03:38 PM