Environmental Sensing

1. Environmental Sensing • Smart Landfill: Landfill gas analysis • Smart Dust: Toxic dust analysis • SmartCoast: Nutrient monitoring • Marine Sensor Systems • Chemical Plume Monitoring • Toxic Metals in Water

2. Smart Landfill Breda Kiernan, Weimin Guo, Conor Slater

3. Aims of the Project • Sponsored by the Environmental Protection Agency, Ireland • Tasked with the development of an autonomous system for monitoring landfill gas emissions and landfill gas migration especially methane and carbon dioxide

4. Analysed using IR gas sensor Chemometric program analyses data and decides if concentrations are within threshold limits Gas sample extracted Borehole well If thresholds are exceeded, a message to sent to personnel onsite to investigate further VOCs CH4 CO2 Landfill gas generation

5. Base-station location Gas monitoring points

6. Current status • Infrared gas sensors (CO2 and CH4) calibrated over the range necessary (0-1.2%) • Wireless comms approaches have been evaluated (GSM, Bluetooth…) • GPS can be used to locate each sensor node and used to generate a dynamic model of the whole landfill site. • Predictions using artificial neural networks of the gas concentrations when compared with the voltage output of the sensors is within 5 %. Therefore, the Smart Landfill system has merit as a warning system using threshold values to determine which concentrations are “normal” and “high” . Infrared sensor for CO2 Perkin Elmer GX FTIR instrument

7. Future Work • Power: Currently 9V battery with 7000 mAh. In the future systems will function through local power scavenging (solar, wind…) • Data retrieval: Inter-sensor distances will be typically 100-500m; ideally suited for variety of low power wireless communications approaches • Field trials for system deployment on target for late September/early October

8. Smart Plant • Sponsored by EPA • Monitoring of odorants at waste transfer stations. • In the first instance, ammonia and hydrogen sulfide are being monitored. • Used as a warning system for build up of chemicals beyond the olfactory threshold.

9. EPA Project: “Autonomous sensors for environmental monitoring- detection of heavy metals in dust” Tanja Radu, Conor Slater, Daniel Kim

10. Elements of the strategy therefore include: Simple sampling and sample processing - ideally on the solid material directly, without reagents Ability to detect a range of targets using a single approach Sufficient selectivity, sensitivity, LOD Relatively low power - sufficient to be operated from local power sources Compatible with digital communications “How can we remotely monitor a range of toxic metals in dust blow-off in real time?”

11. Lead in soil Lead (mg/kg) 3 Gortmore 0 - 400 11 6 400 - 1000 17 1 1000-2000 2000-3000 12 2 8 3000-5000 7 Silvermines 15 5000-10000 14 9 16 10 4 10000+ 5 NOTE: Median concentration of lead in Irish soil is 26 mg/kg !!

12. Arsenic in soil 3 Arsenic (mg/kg) Gortmore 0 - 20 11 6 17 20 - 40 1 40 - 80 80 - 160 12 2 8 Silvermines 160 - 2000 7 14 15 10 16 9 4 5 NOTE: Median concentration of arsenic in Irish soil is 12 mg/kg

13. Dust blow occurrence - a real threat

14. Portable XRF- our method of choice Light, hand held instrument (0.8 kg) Ideal for field analysis Simultaneous analysis of up to 25 elements (Pb, Cd, Sb, Cu, As, Hg, Ag, Zn, Se…) Simple point and shoot operation Real time analysis of solid sample - no lengthy sample preparation Remote operation capability Non destructive method- sample preservation

15. Excellent preliminary results- Pb analysis Trial of XRF in DCU: for soil samples - excellent agreement with AAS For simulated dust samples- excellent correlation of XRF reading and calculated values

16. How to automate XRF? Input info: Temperature Pressure Wind Humidity… XRF ANALYSIS GSM SYSTEM PUMP/SAMPLING MICRO CHIP Wireless communication Sending reading to Internet or mobile phone Remotely controlled NITON 700 XRF instrument EXAMPLE: If T>20 oC, dry and wind = SE then start sampling High flow pump Battery operated Remote control A unique sampling system has been developed by the ASG!

17. Sampler

18. The vision for the future “Smart” instrument – taking samples only when dust blow is likely to occur Autonomous analytical measurement Remote control monitoring Low-power, environment friendly monitoring Real time monitoring Web-based air pollution monitoring system Using this approach we will deliver a remote, real time, system which, for the first time, will provide unambiguous data about the levels of these toxic metals associated with specific blow-off events

19. SmartCoast:Autonomous Phosphate Sensor John Cleary, Conor Slater

20. Autonomous Phosphate Sensor • Component of “SmartCoast” project, which aims to develop a smart water quality monitoring system, to aid compliance with increased monitoring requirements under the Water Framework Directive. • Phosphate is a key limiting nutrient in freshwater ecosystems. • Eutrophication: • A major water quality problem in Ireland and many other countries • Elevated nutrient levels lead to excessive growth of algae and aquatic plants • Oxygen depletion  fish kills • Algal blooms  toxicity in water bodies

21. Objective and Requirements • Develop an autonomous, remotely controlled phosphate sensor capable of monitoring PO43- at appropriate levels at remote locations over long deployments • Requirements: • Sensitive • Stable chemistry • Communicate wirelessly • Low power • Robust & portable • Low cost & low maintenance requirements

22. Principle of Operation • Yellow method for phosphate detection • Forms vanadomolybdophosphoric acid (yellow) • Absorption proportional to phosphate conc. • Advantages • Excellent reagent stability • Fast reaction time (minutes) • Microfluidic technology • Minimizes reagent consumption, storage requirements and pumping power • UV-LED and photodiode • Low powered, inexpensive & sensitive optical detection Talanta vol. 71, no. 3, pp. 1180–1185 , Feb. 2007.

23. Field Trial • First generation sensor was trialled at Osberstown WWTP • 3-week trial with validation using existing online monitor • Good correlation achieved IEEE Sensors Journal (Accepted Aug. 2007)

24. Current Status • Mark II sensor designed to build on the successes and address the limitations of the original. • Improvements • Lower power, more flexible fluid handling system. • More sensitive optical detection system. • More reliable and lower powered communications using GSM modem in SMS mode. • 2 point calibration protocol. • Solar panel for energy harvesting during long deployments. • Improved ruggedisation.

25. Current Status • Preliminary experimentsshow improvement inlimit of detection • LOD ~60 ppb vs. ~300 ppb with original system • Scale-up • 5 units of Mark II Sensor have been fabricated • Currently undergoing laboratory assessment • Field trials to be carried out in coming months

26. Instrumentation interface, communications and data management architecture issues for marine sensor systems, including sea-floor observatories Marine Institute Desk Study: Jer Hayes

27. Background • This desk study project aims to: • To identify key niche areas of innovation in the areas of sensor systems (especially seabed observation) and identify and assess Irish technical and industry capabilities in the technologies involved • To provide solutions to the emerging interface between sensor systems development and operational requirements under the Water Framework Directive • To provide solutions for linking the data acquisition platforms currently in use and planned.

28. SmartBay • The component technologies of SmartBay will include: - a fibre-optic cable from shore to an underwater hub- a variety of instrument nodes and sensor packages a calibration site/facility- multi-beam digital map and geotechnical survey of the area - deployment of a moored buoy, and possibly drifting buoys- navigation and telemetry infrastructure.

29. Current Status • Generated three reports – Current sensory systems and returned data structures used across the MI Establishing protocols for linking data acquisitions platforms with the MI data warehouse The connection of buoys, submarine monitoring stations, coastal and on-shore monitoring systems

30. Interoperability Prior to deployment the puck is loaded with the information that is necessary to fully use the instrument when it is plugged into an sea-floor observatory backbone. Marine Land Wireless sensor networks – can link data acquisition platforms

31. Current Status www.nra.ie ww.met.ie Web Interface Serial Server Database GSM Phosphate Instrument Monitoring program • Adaptive sensing / ambient conditions Phosphate system

32. Additional information • Also worked on - Water purification process monitoring using wireless sensor networks:

33. Monitoring Chemical Plumes in an Environmental Chamber with a Wireless Chemical Sensor Network Stephen Beirne

34. Modified Mica2Dot Mote Opposing LED chemical sensor integrated with modified Mica2Dot wireless sensing platform • Modified to include a power source suitable for laboratory sampling rates. • Opposing LEDs sensor coated in BPB reagent – Sensitive to increase in acidity • Real-time monitoring. Sensor sampled at a frequency of 0.5 Hz. One sample value per data packet • Data Acquisition via Visual Basic interface

35. Wireless Chemical Sensor Assembly Sensor Hood Opposing LEDs Chemical Sensor Limiting Collar Sensor mounting sub-assembly Sensor Mounting Sleeve and Hood connection point Mica2Dot Mote, Radio antenna, 2 x AA battery power supply & On/Off header switch ¼” BSP threaded fitting drilled through Ø 9mm Cylindrical casing Casing End Cap Sensor mounting and protecting sub-assembly of Wireless chemical sensor node enclosure Semi-transparent view of wireless chemical sensor node enclosure assembly • Sensor covered by hood to reduce ambient light. • Node housed in an enclosure to protect electronics from corrosive acetic acid. Also allows for attachment to the Environmental Sensing Chamber.

36. Sensor Reproducibility Smoothed Response Data of Wireless Chemical Sensor Node Exposed to Three Consecutive Plumes of Acetic Acid Laden air • Exposed to acidic vapour by means of a bubbler unit. Bubbler contents 2:1 ratio of Water and Conc. Acetic acid. • Response to stimulus is clearly distinguishable. • Sensor shows excellent reproducibility. • Not a “Single Shot” device – Can be used to monitor consecutive events

37. Sensitive to Plume Flow Rate • Sensor exposed to acidic plumes at varying flow rates. • Higher flow rate induces higher concentration level at node location, as shown by collected data • Data displayed as % Deviation from initial baseline value – Multiple nodes will not have a common baseline

38. Wireless Chemical Sensor Network Arrangement • Developed node allows for a network of similar nodes to be deployed to monitor a chemical plume event.

39. Plume Tracking using a low-cost Wireless Chemical Sensor Network Acidic Plume Active Acidic Plume Inactive & Extraction Active Idle Phase • Sensor network exposed to acidic plume for a period of 200 s (approx). • Dense acetic-acid constrained by river channel walls • Data allows the tracking of plume development through the chamber.

40. Reactive Wireless Chemical Sensor Actuator Network (WCSAN) • Have displayed the ability to track a chemical plume in real-time using a low cost chemical sensor network. • What should we do with the data? …. Use collaborative sensor information. • Event classification - 2 or more sensors display a significant change in response. • Data acquisition software allows output control. • Respond to this event in real-time by sending a control signal from the interface to activate an electro-mechanical purge system. • Results in a real-time reactive Wireless Chemical Sensor Actuator Network (WCSAN)

41. Miniaturized all-solid-state sensors for trace analysis of substances relevant to health and welfare (MASTRA)Aleksandar Radu

42. Miniaturized all-solid-state sensors for trace analysis of substances relevant to health and welfare (MASTRA) • Aim of the project • To develop miniaturised all-solid-state ion sensors with low detection limit based on materials science and ion selective electrodes (ISEs) technology. • Plan • To construct sensors based on novel conducting polymers coupled with novel ion-selective membranes able to achieve trace-level ion detection and stable sensor performance. • To miniaturize created potentiometric device • To apply the sensing device for determination of toxic heavy metals and other ions of importance to human health and welfare.

43. Miniaturized all-solid-state sensors for trace analysis of substances relevant to health and welfare (MASTRA) • Current status • Understanding factors that lead to lowering of the detection limit in classical potentiometric sensors • Potential response of Cs+-selective ISE. • classically prepared ISE. • ISE with optimised inner solution. • Response obtained for electrode B under higher stirring rate of the sample (reducing aqueous diffusion layer thickness). • Response obtained by increasing of the amount of PVC in the membrane cocktail (reduced ion diffusion) and decreasing of the amount of ionic sites. • Radu, Aleksandar;Peper, Shane; Bakker, Eric; Diamond, Dermot: Electroanalysis, 2007, 19 (2-3), 144-154

44. Miniaturized all-solid-state sensors for trace analysis of substances relevant to health and welfare (MASTRA) • Current status cont’d • Development of solid-state potentiometric sensors with low detection limit Response of Pb-selective, solid-contact ISEs in 10-3 M nitric acid. • McGraw, Christina; Radu, Tanja; Radu, Aleksandar;Diamond, Dermot: Electroanalysis, submited

45. Miniaturized all-solid-state sensors for trace analysis of substances relevant to health and welfare (MASTRA) • Current status cont’d • Application of developed soil-contact potentiometric sensor in soil analysis Comparison of Pb2+ concentrations in soil samples digested in 1 × 10-3 M nitric acid obtained by AAS and ISEs. • Radu, Tanja; Radu, Aleksandar;Diamond, Dermot: Proceeding of SPIE Europe, Remote Sensing, Florence, 2007, accepted

46. Miniaturized all-solid-state sensors for trace analysis of substances relevant to health and welfare (MASTRA) • Future directions • Miniaturization of developed solid-state ISEs (lot of experience and expertise in the group, i.e. miniature, microfluidic-based chip in optical analysis (see picture on the right)) • Integration of miniaturized solid-state ISEs with miniaturized solid-state reference electrode (developed by Abo Academi, Finland) (lot of experience and expertise in the group, i.e. field deployable devices (see picture on the right)) • Application in environmental analysis