Few things are as universally important to all Americans as clean drinking water. Regulatory agencies, municipalities, oil and gas exploration companies, and landowners all have a need for water quality assurance. Unfortunately, the most common monitoring solutions are expensive and labor intensive, requiring samples to be collected from the source, prepared, and sent offsite to be analyzed – actions that can dramatically alter the sample.

NETL researchers are hoping to overcome these challenges with a more affordable, in situ monitoring tool based on laser induced breakdown spectroscopy (LIBS). LIBS technology provides rapid elemental analysis without extensive sample collection or preparation. Many of the available LIBS systems are large and complex, employing above-ground, laboratory-scale lasers, but NETL has designed a simple, easy-to-fabricate, handheld LIBS system fully adaptable to field use and capable of measurements even in harsh environments.

“NETL’s system uses a miniaturized, passively Q-switched laser,” said the inventor of the system, Dustin McIntyre, Ph.D.  “The advantage of this kind of laser is that it can provide the same degree of precision timing as conventionally employed, actively switched lasers, but with fewer components, a smaller footprint, and a lower cost.”

The NETL device also boasts a unique split laser design coupled with solid state optics, allowing for both single and multipoint at-a-distance monitoring. LIBS systems can rapidly analyze solids, liquids, and gases and can quickly return results with very little damage to the sample. In a water monitoring scenario, the all-optical sensor can be deployed underground into a source of drinking water.

“To determine what elements are present, the device creates a pulse of light that is amplified and focused to make a spark in the water being measured.” McIntyre explained.  “The spark emits light in all directions, creating characteristic atomic emissions. This light is then back-transmitted through the device, traveling up the optical fiber to the surface. Topside, the light is analyzed by a spectrometer to determine what elements are present.”

This technology will benefit Americans by providing the accurate analysis of elements from within their environments, ensuring safety and quality. In addition to monitoring water quality in both aquifers and water treatment facilities, this kind of analysis could also be used to check for carbon dioxide leakage at storage sites and to help identify rare earth elements that are critical to technologies we rely on every day.

“This technology is real game changer,” McIntyre said. “You basically have a laboratory underground at a fraction of the cost. The affordability of the tool and the simplicity of its operation can open this up to even non-technical people so they have a way to make sure their water is safe.”

Contact:

• Shelley Martin, DOE National Energy Technology Laboratory, 304-285-0228, contact.publicaffairs@netl.doe.gov