Flocculant for removing synedra from water and removing method

Abstract

The invention provides a flocculant for removing synedra from water. The flocculant is formed by matching alum and diallyldimethylammonium chloride, wherein the diallyldimethylammonium chloride belongs to a cationic polymer, and the best weight ratio of the alum to the diallyldimethylammonium chloride is 9 to 12:1. The invention further provides a method for removing the synedra from the water. The method comprises the following steps: removing the synedra from the water by utilizing the flocculant, wherein the concentration of the alum in the water is controlled to be 32 to 48mg/L, and the concentration of the diallyldimethylammonium chloride in the water is controlled to be 2.7 to 4.0mg/L; and then carrying out mixing, flocculation, sedimentation and filtration, thereby removing the synedra. The method has the advantages that the operation is simple, i.e. the only requirement is to proportion the flocculant accurately and then put the flocculant in a distribution well of a water plant; and all the used reagents and operation processes cannot generate secondary pollution and have no harm on environment and human bodies, so that the method is green, clean and environment-friendly. In addition, the removing efficiency of the synedra in the water is high and reaches 90% to 94%.

Description

technical field [0001] The invention belongs to the technical field of water environment protection, and in particular relates to a method for removing needle algae in water supply. [0002] Background technique [0003] Algae outbreaks caused by eutrophication in drinking water sources directly pose a threat to water supply security. Algae blooms have the following major hazards to water supply safety: 1. Algae block the filter, making the filtration of water supply impossible; 2. Make the filter harden and deteriorate, increasing the cost of water supply; 3. Release microcystin and other toxins; 4. Decrease the sense of water body (such as increase of chroma and turbidity of water body, emitting fishy smell, etc.). In May 2007, algal blooms in Taihu Lake affected the normal supply of drinking water for 2 million people. Effectively removing the pollution of various algae in the water body is a difficult problem in the water supply industry at present. [0004] At prese...

AI Technical Summary

Problems solved by technology

In the prior art, the potassium permanganate pre-oxidation method, such as the patent "Potassium permanganate pre-oxidation method and air flotation combined with algae removal water treatment method" with the publication number CN102295363A, has certain inactivation and inhibition of algae cell activity. function, but there are shortcomings such as weak ability to oxidize and destroy algae cell walls, excessive potassium permanganate dosage will increase water color, and produce electronegative manganese dioxide by-products; chlorine pre-oxidation method, and the publication number is CN101723529A's patent "a method of adding chlorine to remove algae and odor in water treatment process" has high algae removal efficiency, especially the effect of removing the water odor produced by algae is better, but because of the addition of chlorine-containing chemicals, disinfection by-products such as Trichloromethane, halogenated hydrocarbons and other substances harmful to humans should also be used with caution; hydrogen peroxide is highly oxidizing and can cause algae cell rupture, causing the release of toxic intracellular substances, which have an impact on the water environment