2. Barite calcination method A solution of barium sulfide is prepared. The sulfuric acid and zinc oxide are reacted, purified by adding potassium permanganate and zinc powder, and compressed to obtain a zinc sulfate solution. Then, the prepared barium sulfide solution is mixed and subjected to a metathesis reaction to obtain a mixture of zinc sulfide and barium sulfate, and then the precipitate is subjected to pressure filtration, calcination, wet grinding, drying, and pulverization to obtain a zinc white product.
In addition to the toxic effects of TiO2 NPs, discussed in previous chapters, these NPs have been also shown to promote photosynthesis and nitrogen metabolism, resulting in the enhanced growth of spinach. It increases the absorption of light and accelerates the transfer and transformation of the light energy. It was also found that treatment with nano-sized TiO2 significantly increased the level of antioxidant enzymes, and decreased the ROS accumulation and malonyldialdehyde content in spinach chloroplasts under visible and UV irradiation. TiO2 NPs also increased the superoxide dismutase activity of germinating soybean, enhanced its antioxidant ability, and promoted seed germination and seedling growth.
Titanium is one of the most common metals on earth, but it does not occur naturally in this elemental form. TiO2, also known as titanium (IV) oxide or titania, is the naturally occurring compound created when titanium reacts with the oxygen in the air. As an oxide, titanium is found in minerals in the earth’s crust. It is also found with other elements, including calcium and iron.