Polyferric Sulfate (PFS), as a new inorganic polymer coagulant, has attracted much attention for its excellent water purification effect since it was developed abroad in the 1970s. It has been developed in China since the mid-1980s and has been widely used in various water treatment fields. However, with the increase of polyferric sulfate products on the market, their quality is also uneven, and the price difference is significant. Starting from several key quality parameters, this paper will introduce how to judge the quality of polyferric sulfate, and give examples for each parameter.
1. Color
Color is one of the most intuitive ways to judge the quality of polyferric sulfate. High quality polyferric sulfate usually appears golden or red in an aqueous solution. For specific operation, you can take a glass, add about 100 ml of water, and then drop two or three drops of polyferric sulfate solution. Observe the color of its diffusion, if the color is bright and uniform, golden yellow or red, it indicates that the polymerized iron sulfate is of high quality. On the contrary, if the color is green or yellow-green, the quality is inferior.
For example, after a brand of polyferric sulfate solution drops into water, it quickly diffuses out a bright golden color, and the color is uniform without impurities, which indicates that its quality is good. The other brand of solution is yellow-green, and the color is uneven, may contain impurities, and the quality is relatively poor.
2. Specific gravity (density)
Specific gravity is one of the important indexes to measure the quality of polyferric sulfate. In general, the higher the density of polyferric sulfate, the better its quality tends to be. The ideal density of polyferric sulfate should be about 1.5g/ml. To detect the density, the polyferric sulfate can be placed in the measuring cylinder, and then the measuring cylinder is placed in the constant temperature pool. After the temperature is stable, the density is measured with a densitometer.
For example, a batch of polyferric sulfate was detected and its density reached 1.52g/ml, much higher than the general standard of 1.3g/ml, indicating that the batch of products are of high quality. The density of another batch of products is only 1.28g/ml, which is significantly lower than the standard value and the quality is relatively poor.
3. Total iron content
Total iron content is one of the key factors to evaluate the quality of polyferric sulfate. The higher the total iron content, the more active ingredients in the product, the better the quality. In general, polyferric sulfate with a total iron content of 13% or more is considered to be of high quality. However, the determination of total iron content is complex and usually requires laboratory experiments to obtain accurate results.
For example, a brand of polyferric sulfate has been tested in the laboratory, and its total iron content has reached 14%, which is much higher than the minimum standard of 9%, indicating that the brand's products are of high quality. The total iron content of the other brand product is only 8%, which is significantly lower than the standard value and the quality is poor.
Four, the salt base
Basicity is an important index to measure the degree of polymerization of polyferric sulfate. The higher the basicity, the greater the degree of polymerization, the larger and denser the condensed flocs, and the faster the sedimentation rate. However, high basicity may also be unfavorable to the removal of some suspended solids. In general, the quality of polyferric sulfate with a base degree between 8 and 16 is better.
For example, a batch of polymerized ferric sulfate was tested and its basicity was 12, which was in the high quality range of 8-16, indicating that the batch of products had a high degree of polymerization and good quality. The salt base of another batch of products is only 6, far lower than the high quality range, and the quality is relatively poor.
5. PH range
The wider the PH range applicable to polyferric sulfate, the wider the environment adapted to its coagulation, and the better the quality. In general, polyferric sulfate is suitable for a PH range of 4-11, but some high quality products may have a wider range of application.
Example: a brand of polyferric sulfate in the range of PH 4-11 have shown good coagulation effect, indicating its wide range of application, high quality. The other brand product is significantly reduced in the PH value is low or high coagulation effect, the scope of application is narrow, the quality is relatively poor.
In summary, the quality of polyferric sulfate can be judged from many aspects such as color, specific gravity (density), total iron content, basicity and PH range. In actual operation, we can choose the appropriate judgment method according to the specific conditions to ensure that the purchased polyferric sulfate products are of good quality.
Focus on water treatment, just for a healthy world! Henan Hongze Environmental Protection Technology Co. is a professional enterprise engaged in the development, production and sales of polymer flocculants. The main products are "green water clean" brand polyaluminum chloride,
Polymerized Ferrous Sulfate, Defoaming Agents,polyferric sulfate and other water purifiers. With an annual output of 10,000 tons, the products are sold all over the country, and actively explore the international market. The company will continue to uphold the business philosophy of "integrity, innovation and win-win", provide customers with quality products and services, and make due contributions to the society.