Industrial wastewater, agricultural wastewater and wastewater produced in daily life will cause serious damage to the natural environment, especially industrial wastewater, which is rich in phosphorus and can accelerate the growth of organic matter, such as algae and bacteria, If it is directly discharged into the river, it will cause serious pollution to the river and affect the normal ecological environment. To avoid this situation, we must treat the sewage and remove the phosphorus in the water.
There are two main treatment methods for phosphorus containing wastewater
1、 Most of the phosphorus can be removed by biological phosphorus removal.
2、 Chemical phosphorus removal method uses chemical agents to react with phosphorus in sewage to produce precipitation, so as to remove phosphorus in sewage and produce purification effect on sewage.
Compared with ferric chloride and ferric sulfate, it is more economical to use polymeric ferric sulfate for phosphorus removal. Moreover, polymeric ferric sulfate is a new type of high-quality inorganic polymer flocculant, which not only has excellent coagulability, but also has fast settling speed. It can not only reduce the total phosphorus content in sewage, but also reduce the input of foreign phosphorus. And different from other chemical phosphorus removal methods, PFS does not contain chlorine, aluminum, heavy metal ions and other harmful substances, and can purify water quality very well. It is a non-toxic and harmless phosphorus removal method.
As an inorganic flocculant, polyferric sulfate has been put into production. However, the single use of polyferric sulfate for phosphorus removal has a large dosage, and the effect is not as good as expected. Therefore, an experimental study on the combined use of potassium ferrate and polyferric sulfate for phosphorus removal in wastewater was carried out. As a new type of water treatment agent, potassium ferrate is a kind of water treatment agent which integrates oxidation, adsorption, flocculation, coagulation, sterilization, decolorization, deodorization, etc. at the same time, it will not cause secondary pollution and other toxic and side effects. This paper is to use the strong oxidation function of potassium ferrate, combined with polymerized ferric sulfate to remove phosphorus in sewage, so as to make the phosphorus content in the effluent reach the first level of national urban sewage pollutant discharge standard.
Compared with organic polymers and inorganic high molecular weight polymers, although the raw materials have wide sources, low prices, and a wide range of better strategies, the relative molecular weight and particle size are not high enough, and the total adsorption bridging capacity is not strong. In particular, the adsorption bridging capacity of colloidal substances is much higher than that of organic high molecular weight polymers, and there are still problems such as further hydrolysis instability and drug dosage, It has the disadvantages of producing more sludge and difficult post-treatment. High molecular weight, flocculation effect, adsorption capacity of colloidal substances of bridge, good application range and stability, small dosage, less sludge, etc. The disadvantages are that the synthesis technology is complex, the dosage range of good drugs is narrow, and the cost of water treatment is too high. The advantages of inorganic polymer are better efficiency than traditional metal salt flocculant, lower price than organic polymer, etc. In view of the selection of two kinds of flocculants and their respective advantages and disadvantages, the existing flocculants are highly complementary in their performance and cost, and encourage people to come. At the same time, they will become a kind of complex organic-inorganic flocculants, overcome their respective disadvantages, enhance efficiency and expand application fields.