Copper sulfate, management

One borderline circumstance, which should be considered as intentional chemistry for purposes of managing chemical reactivity hazards, is hydration. For example, anhydrous copper sulfate is a white solid with the formula CuS04. When it is crystallized from water, a blue crystalline solid with the formula CuS04-5H20 results, and the water molecules are an integral part of the crystal (Parker 1997). 

The Ti-normalized data emphasize the enrichment in Cu at 10.5 cm (1987), a very striking feature of the MTR data. Associated with the copper peak are corresponding major peaks in S and IRM and lesser ones in Fe, Zn, and As (Zn only shows up as a peak in Ti-normalized plots). We believe these maxima at 10.5 cm are unrelated to power plant emissions. Copper sulfate is commonly added to reservoirs to retard algal growth. The manager of the water department in the town of Spencer, Lowell Hardmann, reported to us that copper sulfate was indeed added to the reservoir, but he did not have information on the exact date. Since Cu is not an element associated with power plant emissions and we know of no other significant Cu source nearby, the most likely explanation is that the copper sulfate additions were made in about 1987 coincident with the peak. The dramatic increase in Cu/Ti for reservoir sediments at 10.5 cm compared to nearby soils (Fig. 12) and rocks (Table 7b) is consistent with this conclusion. 

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