08-14-2018, 04:59 PM
quote:
Originally posted by ironyak
I do have to question one thing Dr Thomas said though - "when we look at the chemistry of the fluids we don't find high levels of toxic elements like arsenic or boron or ammonia in Hawaii's geothermal fluids because the rocks are not rich in those elements. ... Geyer's geothermal fields ... there is mercury, lead that has contaminated the streams..."
However, in the analysis of PGV brine arsenic (Ar) has been over 2000 ppm, and mercury (Hg) has been around 2 ppm, which is way higher than the Geyer's Geothermal field values of 0.2 ppm for arsenic and 0.005 ppm for mercury. PGV's brine does have Lead (Pb) as well, up over 4%, but I don't have numbers for boron or ammonia to compare which may be what he was trying to highlight? I'm sure someone can clarify this point hopefully.
PGV Brine Analysis (Table 1): http://pubs.geothermal-library.org/lib/grc/1028353.pdf
Geothermal Energy (Table 8.1 Contaminant concentrations) http://unesdoc.unesco.org/images/0013/00...33254e.pdf
ironyak, You might want to read the title of that article a little more carefully: those analyses in Table 1 were of scale material collected from various places in the PGV power plant - not from brine samples. The concentrations in the scale are very different from the concentrations in the brine. The table lists the gold concentration as 17 oz. per ton of material and silver at 399.6 oz. per ton - if that was the concentration in the brine, there would be a lot more geothermal wells in Puna than there are today...