Effects of Tourmaline Powder on Growth Activity of Marine Bacteria and Diatoms

The effect of tourmaline on growth activity of marine bacterium and the diatom Navicula perminuta was investigated by testing number of bacteria in fresh nature seawater and chlorophyll a of the diatom suspension. The concentrations of magnesium, iron and lithia tourmaline powders were controlled from 1 g/L to 15 g/L. The results showed that bacterial cells in seawater and chlorophyll a of diatom solution were reduced with increase of tourmaline powder. Tourmaline could inhibit obviously the growth activity of marine bacteria and diatom. The inhibiting effect of lithia tourmaline is strongest, that of magnesium stronger, and that of iron weakest. Whatever the tourmaline type, the higher the negative ion release rate is, the stronger is the inhibiting effect of tourmaline on growth activity of marine bacteria and diatom. Tourmaline mineral materials are expected to use as an additive to antifouling coatings from this work.