Vanadium toxicity and environmental safety
First, the toxicity of vanadium The toxicity of vanadium is closely related to its valence and water solubility. High-valence vanadium is easily soluble in water and is highly toxic. Atmospheric vanadium compounds have a stimulating effect on the skin and respiratory tract. Long-term exposure to V 2 O 5 dust and V 2 O 5 thick environment can cause respiratory irritation accompanied by mucus production, bronchitis, chest pain, dermatitis and the like. Second, the environmental safety indicators of vanadium For a place where 8 hours of work per day and 40 hours of work per week, the upper limit of vanadium-containing dust is 0.5 mg/m3, and the upper limit of fine dust environment should be 0.05 mg/m3. The upper limit for short-term workers is 1.5 mg/m3. The toxicity of vanadium compounds is listed in Table 1. Table 1 Toxicity of vanadium compounds Compound Oral and lethal dose of kilograms of body weight LD 50 (14d)/mg Inhaled lethal dose LD 50 (14d) / (mg · L - 1 ) Kilogram weight epidermal lethal dose LD 50 (14d)/mg male female male female male female Analytical pure V 2 O 5 470 467 11.09 4.3 >2500 >2500 Industrial pure V 2 O 5 8713 5639 >6.65 >6.65 >2500 >2500 Ammonium metavanadate 218 141 2.61 2.43 >2500 >2500 Potassium metavanadate 318 314 1.85 4.16 >2500 >2500 From a biological point of view, vanadium is a very important element. It is known that vanadium contributes to the function of biological nitrogen fixation. Due to the discovery of vanadium halide peroxidase in seaweed, it has ignited a boom in its research. Because it can form an intermediate of enzyme-vanadium hydrochloride, vanadate is The cells are easily reduced to a tetravalent state and exist as VO 2 + . In the extracellular, animal body fluids, it is easily oxidized by air to pentavalent, and exists as VO 3 - . Vanadium in the cell can promote the phosphorylation and de-phosphorylation of cellular process, control the activity of many enzymes, and participate in the regeneration of free radicals. It is believed that vanadium has an anticancer effect in the body. Studies have shown that glutathione S-transferase (CST) is a detoxification enzyme for cancer. In the screening of trace element feeding experiments, drinking water containing NH 4 VO 3 in the mucosa of the liver and kidney of the test mouse, It was found that the activities of glutathione and CST were significantly improved, and thus vanadium was considered to have an anticancer effect. Rotary drum flaker is a kind of rotating continuous drying equipment with internal heating conducting function. The material film will stick to the bottom of the rotating cylinder. The heat is transferred to the internal wall of the cylinder through piping system and it will be conducted to the external wall and material film. The moisture of the wet material film will be easily evaporated and the dried material will be scraped from the cylinder surface and transfer to the packing area by the screw conveyor. Drum Flaker,Rotary Drum Flaker,Drum Dryer Flaker,Rotary Drum Scraper Dryer Changzhou Lead Machinery Technology Co.,Ltd , https://www.leaddryer.com