Presumably many people engaged in the fertilizer industry remember the American diammonium in the 1980s and 1990s, which was once regarded by farmers as a "magic pill" with high grain yield. Because domestic fertilizer practitioners cannot produce diammonium with the same quality as foreign brands, many diammonium manufacturers have started using brown dyes. The rise of fertilizer stains in China stems from this brown "magic". Later, China's fertilizer production began to use colorants, compound fertilizers, urea can not escape the temptation, water-soluble fertilizers, controlled release fertilizers, coated fertilizers and other new fertilizers have also been put on a layer of colored coat. Generally speaking, there are several types of fertilizer stains: 1. Water-soluble dyes, pigments or oil-soluble indigo. 2. Naturally colored substances, such as humic acid, certain polysaccharides. 3. Inorganic pigments, such as iron oxide series pigments. Taking sunset yellow, a food additive approved in China as an example, in accordance with the "Sanitary Standards for the Use of Food Additives" (GB2760), it is used for the color decoration of fruit juice drinks, carbonated drinks, candies, and pastries. The maximum allowable amount is 0.1 g / kg , That is, the addition amount of 0.1 ‰. Syrup is used for jam, fruit flavoring, mayonnaise and salad dressing. The maximum allowable amount is 0.5 g / kg, which is 0.5 ‰. According to veterans of the fertilizer industry, the amount of pigment added to water-soluble fertilizers is generally around 0.4 ‰, which is less than the allowable amount of salad dressing that people can directly eat. It is true that fertilizer companies have used high-toxic dyes such as pyridine, enquinone, and bisazo to color fertilizers, but this happened 10 years ago. Because of various factors such as cost, companies have rarely used it. So, is the ferric oxide pigment, one of the chemical products, polluting the soil? First, as a colorant, the amount of iron oxide is very small; second, iron oxide is not a heavy metal, non-toxic, and can supplement the iron element lost in the soil. Therefore, iron oxide dyes are not polluting the soil. The state encourages the development of water-soluble fertilizers. Most enterprises add water-soluble pigments, and some enterprises use food-grade pigments, such as lemon yellow, indigo, apple green, and carmine. C. Why do we add dyes to fertilizers? Take water-soluble fertilizer as an example: First, many production companies design different formulas in different colors, allowing farmers to quickly identify fertilizers by color, and will also reasonably correspond to the fertilizer formula that should be used at different growth stages of each crop. Secondly, the concentration of fertilizer cannot be seen directly after dilution without dyeing the fertilizer, which often misleads the farmers. After dyeing the fertilizer, it is easy for the farmers to judge the concentration of the fertilizer after the dilution. Third, many fertilizer manufacturers add very few trace elements or additives to the fertilizer, and they need to determine whether the mixing effect of the fertilizer has reached the ideal state based on the appearance of the fertilizer. Disclaimer: Some articles on this website are transferred from the Internet. If you have third party legal rights, please inform this website to deal with them. phone YT-H711 YT-H711 Shenzhen Sunshine Technology Co.,Ltd , https://www.yatwin.com
A. What are the types of dyes?
B. Is fertilizer staining contaminated soil?