Chloride ion passivant, preparation method of passivant and treatment method for desulfurization wastewater

Abstract

The present invention provides a chloride ion passivant. The passivant comprises the following components in percentages by mass: 0.001-0.2%of an amine, 0.0001-0.01% of an ester, and the balance of water, wherein the amine is polyacrylamide and/or alkenylamine, and the ester is an acrylic acid-acrylate copolymer or an acrylic acid-AMPS-maleic anhydride terpolymer. The invention also provides a preparation method of the chloride ion passivant; and the invention also provides a treatment method for desulfurization wastewater, wherein the treatment method uses the above chloride ion passivant. According to the treatment method, after the passivant is added into the desulfurization wastewater, chloride ions are deactivated, chloride ion corrosion is inhibited, the desulfurization wastewater isconverted into non-corrosive ordinary wastewater for evaporation and crystallization treatment, so that the investment costs of the system are significantly reduced, the service life of the system isgreatly prolonged, the reliability of the system is greatly improved, no by-products appear, zero discharge treatment of the desulfurization wastewater is realized, and the water resource environmentis protected.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a chloride ion passivator, a preparation method and a desulfurization wastewater treatment method. Background technique [0002] Limestone-gypsum wet desulfurization technology is widely used in my country. At present, more than 90% of coal-fired power plants in my country use this technology to remove sulfur dioxide in flue gas. The desulfurization process will produce desulfurization wastewater during operation. The wastewater has the characteristics of high salt content, high concentration of suspended solids, high hardness, high concentration of chloride ions, and some heavy metal ions. It is the most difficult wastewater to treat in coal-fired power plants. one. [0003] The country is gradually strengthening the control of various types of water pollution, and it is an inevitable problem to choose low-cost and high-efficiency technologies to treat desulfurizat...

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Problems solved by technology

[0004] It can be seen from the DL / T 997-2006 "Water Quality Control Indicators for Limestone-Gypsum Wet Desulfurization Wastewater in Thermal Power Plants" that the concentration of chloride ions in the existing desulfurization wastewater can reach up to 20000mg / L, which is extremely corrosive. During the discharge treatment process, both equipment and flue will be severely corroded. At present, the technical solution adopted in the industry is to use corrosion-resistant metal materials; the second solution is to paint anti-corrosion materials on ordinary steel materials, but the above two technologies However, there are technical risks such as high price, short lifespan, and difficulty in ensuring reliability, which have become the bottleneck restricting the promotion of zero discharge technology for desulfurization wastewater.

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