Applications of Photonics in Environmental Sciences

Globally, ecosystems are increasingly facing threats. The progressive pace of industrialization, pressure from increasing populations and expanding urbanization, as well as climate changes can wreak havoc on emerging economies and have social and health effects. Not surprisingly, Scientists, Researchers and governments are investing substantial resources into monitoring and preventing these environmental threats.

Avantes is one of the top innovators in the development and application of fiber optic spectroscopy instruments and systems. The company’s mission is to provide advanced measurement equipment that allows people to live longer, healthier lives and saves the planet for future generations, so it is not a surprise to find Avantes instruments at the forefront of environmental science.

Industries and Methods

As all sorts of industries advance across the global marketplace, both the need for ecological monitoring and the technology to achieve it, progress as well. Several spectroscopic measurement methods are turning out to be effective and versatile for environmental applications. Fluorescence measurements are a common choice for detecting if hydrocarbon pollutants are present, 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 absorbance spectroscopy is used in water quality monitoring of coastal waterways.

The need for ecological and environmental testing and measurement is continuously on the rise and there are several spectroscopy techniques available. An Avantes Engineer can help establish the precise approaches and optimized system specifications to design the perfect spectroradiometry solution for specific measurement needs.

Spectroscopy Solutions in Water and Soil Contamination

Contamination Monitoring

Researchers at the Institute of Solar Energy and the Technical University of Madrid, Spain, depend upon the Avantes Ava-Spec 2048-USB2-UA for their research into the employment of high-powered UV LEDs as an excitation source for nonstop use of fluorescence sensing. With recent advancements in LED technology, these cost effective bulbs have become an appealing alternative. Traditional incandescent mercury bulbs generate a large quantity of heat compared to LEDs, which, integrated with their short life, make nonstop use impossible.

The task involved the mapping of detection errors to degradation of optical output power and determination of a degradation limit of 30%. This means that the practical life of the bulb requires sustaining 70% of initial output power. For high-powered UV-LEDs, they estimated this was approximately 6200 hours of continuous use or, based on the bulb, up to 66,000 hours of cycled use (30 second on/ 30 second off) which indicates a considerable improvement over traditional bulbs. These Researchers are working to introduce real-time, nonstop monitoring for hydrocarbon pollution to fruition.

Researchers from the College of Control Science and Engineering at Zhejiang University, publishing in the May 2017 issue of Journal of Spectroscopy, are involved in developing a technique for fast, on-site water quality analysis in the case of unidentified contaminants. Their technique uses fluorescence spectroscopy. They applied an alternating trilateral decomposition (ATLD) algorithm, after removing Raman scattering effects, to create a model of a “normal” water sample. The Researchers working with an excitation wavelength of 350 nm and an emission wavelength of 397 nm believe they were able to create a model to detect the presence of unidentified organic contaminants with fluorescent properties. This study on building a profile of “normal” water (water without organic contaminants) has the prospect for the development of real-time, inline water quality monitoring systems.

Water Treatment

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

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

Traditionally, the photo-Fenton reaction depended on solar radiation as the source of catalytic radiation, but solar cycles and weather conditions make artificial illumination an appealing alternative. Lately, this has been achieved using Mercury lamps which have a restricted lifespan and high cost linked to them. The Spanish Researchers are examining the efficiency of newly available LED light sources for UV radiation with positive results. When compared to traditional incandescent bulbs, LED bulbs are less expensive and offer a longer life.

Soil Contamination Applications

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

Spectroscopy in Nuclear Materials Monitoring

Globally, nuclear power is used to supply residential and commercial power requirements without the same carbon footprint of coal fired power; however, nuclear power comes with its own hazards. A collaborative team of Researchers from institutions in Finland, Romania, Estonia and Germany, used the Avantes AvaSpec-ULS2048-USB2 spectrometer

In their work with laser-induced breakdown spectroscopy to analyze composites of tungsten and beryllium, the Researchers detected doped samples of deuterium. This research will add to the development of in situ monitoring of deposit layers in plasma-facing surfaces of fusion reactors, enhancing safety and efficiency.

At the Savannah River National Laboratory plutonium processing site, Avantes instruments are at the center of recent innovations. The new Savannah River spectrophotometer monitoring system replaces colorimeters used to establish plutonium concentration in solution with Avantes AvaSpec-ULS3648 instruments. Besides being significantly more accurate, the new system is easier to troubleshoot, calibrate and repair resulting in less downtime and better safety.

Monitoring the Environment

Oceanographic Research

The health of the oceans and seas has dire consequences for humanity. The ocean produces more than half of the oxygen present in the atmosphere and about half the world’s population reside near a coastal zone. Protecting the earth’s oceans is crucial and Researchers are using spectroscopy more and more to monitor the health of the oceans and seas.

Remote sensing (primarily from satellites as early as the 90’s, but progressively from UAVs) has been used to observe the health of coral reefs using pulsed laser fluorescence. Symbiotic algae and the byproduct chlorophyll with fluorescence peaks at 685 and 740 nm can be detected.

Another team of  Researchers exploring ocean and coastal waterways have been building models to anticipate intense phytoplankton blooms using irradiance spectroscopy. These intense destructive blooming events unfavorably impact ecosystems and can be detrimental for human health as well. Using UAVs equipped with an Avantes AvaSpec dual channel spectroradiometry solution covering 360-1000 nm, the team was able to derive fine-resolution spectra data and acquire timely information on bloom magnitude. While the technology is yet to mature, these Researchers suggested preliminary implementation of spectral bloom monitoring during algal bloom season.

Wildfire Detection and Mitigation

NGNS, the Portuguese firm, manufactures a long range wildfire detection system called ForrestfireFinder which employs Avantes spectrometers to deploy its fire monitoring system across the dry central Iberian peninsula where wildfires are a recurrent danger.

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

Avantes at the Forefront of Environmental Research

Avantes spectroscopy instrumentation is trusted by climate and environmental Researchers all over the world for accurate, consistent spectral measurements. With over two decades experience in supporting the special needs of various industries and applications, Avantes can be a trusted partner in meeting customer’s measurement objectives. Avantes’ innovative designs and commitment to progress the science of photonics means that Avantes spectrometers are constructed to manage the new and innovative uses esearchers are discovering for spectroscopy.

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.

This information has been sourced, reviewed and adapted from materials provided by Avantes BV.

For more information on this source, please visit Avantes BV.