Photonics Applications in Environmental Sciences

Photonics Applications in Environmental Sciences
 
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Ecosystems around the world are facing growing threats. The increasing pace of industrialization, pressure from growing populations and increasing urbanization, as well as climate changes can wreak havoc on emerging economies and have health and social implications. Not surprisingly, researchers, scientists and governments are investing significant resources to monitoring and preventing these environmental hazards.

Avantes is a leading innovator in the development and application of fiber optic spectroscopy instruments and systems. Our mission at Avantes is to provide state of the art measurement equipment that allows people to live longer, healthier lives and saves the planet for generations to come, so it’s no wonder that Avantes instruments are found at the forefront of environmental science.

Industries and Methods

As industry of all sorts advance throughout the global marketplace, both the need for ecological monitoring and the technology to implement it, advance as well. Several spectroscopic measurement techniques are proving to be effective and versatile for environmental applications. Fluorescence measurements are a typical choice for detecting the presence of hydrocarbon pollutants, while Raman spectroscopy might be used to identify organic contaminants. Laser induced breakdown spectroscopy (LIBS) and fluorescence measurements are both used in processing nuclear material, and we see absorbance spectroscopy used in water quality monitoring of coastal waterways.

The need for environmental and ecological testing and measurement is constantly on the rise and there are a number of spectroscopy methods available. An Avantes engineer can help determine the right methods and optimized system specifications to design the right spectroradiometry solution for your measurement needs.

Spectroscopy Solutions in Water and Soil Contamination

Contamination Monitoring

water contamination 640Researchers with the Institute of Solar Energy and the Technical University of Madrid, Spain, trust the Avantes Ava-Spec 2048-USB2-UA in their research into the use of high-powered UV LEDs as an excitation source for continuous use fluorescence sensing. LED technology has advanced recently making these cost effective bulbs an appealing alternative. Traditional incandescent mercury bulbs produce a large amount of heat compared to LEDs, which, combined with their short life, make continuous use impossible.

The work required the mapping of detection errors to degradation of optical output power and determined a degradation limit of 30%. This means that the useful life of the bulb requires maintaining 70% of initial output power. For high-powered UV-LEDs, they estimated this was approximately 6,200 hours of continuous use or, depending on the bulb, up to 66,000 hours of cycled use (30sec on/ 30sec off) which represents a significant improvement over traditional bulbs. These scientists are working to bring real-time, continuous monitoring for hydrocarbon pollution to fruition.

Researchers from the College of Control Science and Engineering at Zhejiang University, publishing in the May 2017 Journal of Spectroscopy, are working to develop a method for rapid, on-site water quality analysis in the case of unknown contaminants. Their method employs fluorescence spectroscopy. They applied an alternating trilateral decomposition (ATLD) algorithm, after eliminating Raman scattering effects, to establish a model of a “normal” water sample. Working with an excitation wavelength of 350 nm and an emission wavelength of 397 nm, the researchers believe they were able to establish a model to detect the presence of unknown organic contaminants with fluorescent characteristics. This work on developing a profile of “normal” water (water without organic contaminants) has the potential for the development of real-time, inline water quality monitoring systems.

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Water Treatment

The Avantes AvaSpec-ULS2048-2 is trusted by researchers at the Solar Energy Research Center and Chemical Engineering Department of the University of Almería, Spain, in the study of LED light sources for tertiary wastewater treatment processes

Tertiary treatment is the final stage of wastewater treatment that removes lingering inorganic compounds and other substances such as nitrogen and phosphorous. This photocatalytic process, employing UVA radiation at 365, 385 and 400nm, is the photo-Fenton Reaction in which radiation causes a rapid reaction between hydrogen peroxide and iron.

Historically the photo-Fenton reaction relied on solar radiation as the source of catalytic radiation, but weather conditions and solar cycles make artificial illumination an attractive alternative. Recently, this has been accomplished using Mercury lamps which have a limited lifespan and high cost associated with them. The Spanish researchers are testing the effectiveness of newly available LED light sources for UV radiation with positive results. LED bulbs are less expensive than traditional incandescent bulb and have a longer life.

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Soil Contamination Applications

The use of laser induced breakdown spectroscopy is widely used for soil contamination detection. Researchers from the Department of Environmental Sciences of the Government College University, Faisalabad, Pakistan are studying Chromium VI and other heavy metal contamination from industrial waste produced by the economically important leather tanning industry. The Avantes AvaSpec 3648-USB2 Dual Channel spectrometer system working in the 300-750 nm wavelength range provided researchers with quantitative and qualitative analytical data with a very low detection limit.

Spectroscopy in Nuclear Materials Monitoring

Nuclear power is used around the world to supply commercial and residential power demands without the same carbon footprint of coal fired power, but nuclear power comes with its own risks. Researchers came together from institutions in Finland, Estonia, Romania, and Germany, and used the Avantes AvaSpec-ULS2048-USB2 spectrometer

in their work with laser-induced breakdown spectroscopy to study composites of beryllium and tungsten, detecting doped samples of deuterium. This work will contribute to the development of in situ monitoring of deposit layers in plasma-facing surfaces of fusion reactors, improving safety and efficiency.

At the Savannah River National Laboratory plutonium processing site, Avantes instruments are at the core of recent innovations. The new Savannah River spectrophotometer monitoring system replaces colorimeters used to determine plutonium concentration in solution with Avantes AvaSpec-ULS3648 instruments. In addition to being considerably more accurate, the new system is easier to troubleshoot, calibrate, and repair leading to less downtime and improved safety.

Monitoring the Environment

algea bloom 740Oceanographic Research

The health of our oceans and seas has dire consequences for humanity. The ocean produces more than half of the oxygen in our atmosphere, and roughly half the world’s population lives in a coastal zone. Protecting our oceans is vital and researchers are increasingly using spectroscopy to monitor the health of the world’s seas and oceans.

Remote sensing (initially from satellites as early as the 90’s, but increasingly from UAVs) has been used to monitor the health of coral reefs using pulsed laser fluorescence. Detecting symbiotic algae and the byproduct chlorophyll with fluorescence peaks at 685 and 740 nm.

Another group of researchers studying ocean and coastal waterways has been developing models to anticipate intense phytoplankton blooms using irradiance spectroscopy. These intense harmful blooming events adversely affect ecosystems and can be adverse for human health as well. Using UAVs fitted with an Avantes AvaSpec dual channel spectroradiometry solution covering 360-1000nm the team was able to derive fine-resolution spectra data and obtain timely information on bloom magnitude. While the technology is still maturing, these researchers recommended initial implementation of spectral bloom monitoring during algal bloom season.

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Wildfire Detection and Mitigation

The Portuguese firm NGNS is the maker of the ForrestfireFinder, a long range wildfire detection system that utilizes Avantes spectrometers to deploy their fire monitoring system across the arid central Iberian peninsula where wildfires are a frequent danger.

More researchers are using spectroscopy to evaluate damage and impacts to topsoil from wildfires, monitor vegetation recovery after a fire, or measure moisture content and assess risk.

Avantes at the Forefront of Environmental Research

Avantes spectroscopy instrumentation is trusted by environmental and climate researchers around the world for accurate, robust spectral measurements. With more than 2 decades experience in supporting the unique needs of diverse industries and applications, we are your trusted partner in meeting your measurement objectives. Our innovative designs and commitment to advancing the science of photonics means that Avantes spectrometers are built to handle the new and innovative uses researchers are finding for spectroscopy.

Where to Learn More

Contact us today to speak with an expert sales engineer about your unique application needs.

 

 

 

Resources

  • J. A. S. Pérez et al., Low cost UVA-LED as a radiation source for the photo-Fenton process: a new approach for micropollutant removal from urban wastewater. Photochemical & Photobiological Sciences, vol. 16. pp. 72–78, 19-Jan-2017.
  • Jie Yu, Xiaoyan Zhang, Dibo Hou, et al., Detection of Water Contamination Events Using Fluorescence Spectroscopy and Alternating Trilinear Decomposition Algorithm. Journal of Spectroscopy, vol. 2017, Article ID 1485048, 9 pages, 2017. doi:10.1155/2017/1485048
  • Arques-Orobon, Francisco Jose et al. Functional Analysis in Long-Term Operation of High Power UV-LEDs in Continuous Fluoro-Sensing Systems for Hydrocarbon Pollution. Ed. Gonzalo Pajares Martinsanz. Sensors (Basel, Switzerland) 16.3 (2016): 293. PMC. Web. 25 July 2017.
  • Shakeel Ahmad Khan, Muhammad Ibrahim, et. al.  Spectrochemical Analysis of Soil around Leather Tanning Industry Using Laser Induced Breakdown Spectroscopy. Journal of Chemistry, vol. 2013, Article ID 894020, 6 pages, 2013. doi:10.1155/2013/894020.
  • J Karhunen et al 2014 Development of laser-induced breakdown spectroscopy for analyzing deposited layers in ITER -  Phys. Scr. 2014 014067, 25 Jul. 2017.
  • Innovation Improves Plutonium Processing at Savannah River Site Department of Energy, 25 Jul. 2017.
  • Hardy, JT, et al. 1992 Remote detection of coral 'bleaching' using pulsed-laser fluorescence spectroscopy. Marine Ecology Progress Series 88(2-3):247-255  November. 1992
  • DOI: 10.3354/meps088247
  • Shang, Shaoling, et al. Sensing an intense phytoplankton bloom in the western Taiwan Strait from radiometric measurements on a UAV. Remote Sensing of Environment, Vol. 198 1 September 2017, Pages 85-94.