Azimi, H. ; Hannagan, R. ; Howe, G. ; Nagarajan, R. ; Ponrathnam, T. ; Robertson, S. ; Ryan, D. ; Sullivan, C. ; Yu, S. R.
Heavy metals; Detection; Voltammetry; Environmental testing; Field characterization; E-Tongue; Arsenic; Cadmium; Lead; Mercury; Zinc;INDUCED BREAKDOWN SPECTROSCOPY; ANODIC-STRIPPING VOLTAMMETRY; SCREEN-PRINTED ELECTRODES; ORGANIC POLYMERS; SOILS; GROUNDWATER; SYSTEM; FLUORESCENCE; ENVIRONMENT; SUBSURFACE
Heavy metals from both natural and anthropogenic sources present a significant risk to human and environmental health. A number of methods have been developed for the detection and quantification of heavy metals. These methods include laboratory analysis, onsite testing of samples, and in situ techniques. This paper will review current and emerging technologies for site characterization with a specific focus on in situ detection of heavy metal contamination in geoenvironmental remediation projects. In addition, on-going research performed for the development of an in situ voltammetric sensor system will be presented. A number of devices exist for the efficient sampling of contaminated groundwater including the Hydropunch, BAT system, and Cone Sipper. Samples may either be sent to a laboratory for analysis with techniques such as atomic absorption spectroscopy, inductively coupled plasma-mass spectrometry, atomic emission spectroscopy, and X-ray fluorescence, or analyzed onsite using methods such as colorimetry, voltammetry, or biological based chemical sensors. For in situ analysis of heavy metals in soil, X-ray fluorescence and laser induced breakdown spectroscopy technologies have been integrated with the cone penetrometer probe. This paper further explores the feasibility of integrating electrochemical techniques based on voltammetry for the in situ detection of aqueous metal ions. The development of bismuth, gold nanoparticle, and polymer modified electrodes allow for the detection of heavy metal contaminants, including lead, cadmium, mercury and arsenic, at low part per billion levels.