Watergenics AISRAS : Addressing Problems of In-Situ, Real-Time Measurement of Total Iron and Sulfate Concentrations from Natural Acid Rock Drainage in the Andes

Our study compares the performance of real-time augmented in-situ Raman spectroscopy (AISRAS) with laboratory ion chromatography in a remote post-mining site in the Andes. We measured two points over four months, one with high levels of sulfate and total iron in the waters and one with low levels. Laboratory ion chromatography tests serve as a reference. The results suggest that AISRAS performs very well in the harsh weather conditions of the Andes highlands, even in shallow waters with high suspended and dissolved solids concentrations. The AISRAS technology has proven to be an effective solution for real-time monitoring of sulfate and total iron in naturally formed acid-rock drainage. Daily fluctuations and long-term trends were identified, with an average deviation for sulfate of 4.7% and for total iron of 7.9% compared to the ion chromatography laboratory tests. The recommended maintenance of the ABAIA probe lens was every 25 days.