Desulfurization wastewater dechlorination treatment method and desulfurization wastewater treatment equipment

Abstract

The invention discloses a desulfurization wastewater dechlorination treatment method and desulfurization wastewater treatment equipment. The method comprises the following steps: A, firstly, adding anacid into the desulfurization wastewater to adjust the pH value to 0.5-4, and then stirring and mixing with a liquid resin; B, separating an obtained mixture in a separation chamber; C, enabling theseparated liquid resin to enter a liquid resin buffer tank, and enabling separated desulfurization wastewater to enter a next-stage reactor for further treatment; and D, repeating the steps A, B and Cin the treatment process, removing the liquid resin dissolved in the water in an air floatation oil removal device, taking the desulfurization wastewater treated through air floatation treatment andpH adjustment as reuse water, and conveying the liquid resin brought out by bubble floatation into the liquid resin buffer tank. The method has the advantages that the equipment investment is small, the operation cost is low, the produced water after chloride ion removal can meet the industrial water recycling requirement, no waste is generated in the treatment process, real-time adsorption and real-time regeneration are achieved in the reaction process, 100% removal of chloride ions can be achieved, the whole process is continuously operated, waiting and time delay are not needed, and the production efficiency is high.

Description

technical field [0001] The invention relates to an industrial (desulfurization) wastewater treatment technology, in particular to a dechlorination treatment method for desulfurization wastewater and desulfurization wastewater treatment equipment. Background technique [0002] In order to protect the resources and environment and meet the requirements of environmental protection, it is necessary to desulfurize the wastewater generated in industrial production. In the prior art, the following two processes are usually used to treat industrial wastewater: [0003] 1. Desulfurization wastewater adopts triple box + softening + concentration + evaporation + crystallization process [0004] Its existing problems are: [0005] 1. Due to the use of the membrane method for concentration treatment, there are requirements for the total salt content of desulfurization wastewater, and higher requirements for the content of calcium and magnesium ions. In the actual operation process, the ...

AI Technical Summary

Problems solved by technology

[0005] 1. Due to the use of the membrane method for concentration treatment, there are requirements for the total salt content of desulfurization wastewater, and higher requirements for the content of calcium and magnesium ions. In the actual operation process, the recovery of membrane fouling is the most important task, and the maintenance amount of the membrane aggravated;

[0006] 2. Due to the different types of membranes, the membranes to be used in the system include microfiltration, ultrafiltration, reverse osmosis, high-pressure reverse osmosis, etc. The maintenance of the system is complicated, the equipment investment is large, and the operating cost is high;

[0008] 4. The end product is salt, and the power plant is not qualified to sell salt to make salt. This part of the product can only be treated as solid waste and hazardous waste, and the treatment cost is high

[0011] 1. This treatment method has requirements on the amount of flue gas. Normally, the amount of flue gas required to treat 1 ton of desulfurization wastewater is 9000-10000Nm 3 At the same time, it is used to treat 5%-6% of the total flue gas volume of desulfurization wastewater. Due to the salt crust effect of the treated fly ash, it is difficult to fully evaporate the water, and the disadvantage of high moisture content in the fly ash may occur. It is easy to cause corrosion to subsequent pipelines and dust removal equipment;

[0012] 2. A set of desulfurization wastewater bypass flue evaporation device is installed behind each unit, the system is complex; maintenance is increased, and equipment investment is large;

[0013] 3. Since the fly ash produced is highly salt-containing fly ash, when it enters the electrostatic precipitator, part of the fly ash stays on the electrode due to electrostatic attraction, which corrodes the corona electrode greatly, which may easily cause the failure or partial failure of the electrostatic precipitator. Adverse effects on the quality of flue gas at the rear end;

[0014] 4. When this method is used on a 300MW unit, since the temperature of the flue gas after the air preheater is reduced, it will affect the thermal efficiency of the boiler, usually reducing the thermal efficiency of the boiler by about 0.4%;

[0016] 6. Since the desulfurization wastewater treatment system is installed on the boiler flue gas treatment section, the actual operating conditions of each unit have a great impact on the desulfurization wastewater treatment device. The operation of the unit and the desulfurization wastewater treatment device must be associated, resulting in a more complicated control system. The device cannot recycle the treated water during treatment, and the waste of water resources is serious

[0017] From the above analysis, it can be seen that desulfurization wastewater is the terminal wastewater of industrial production or power plants, which is difficult to treat. The most difficult thing to deal with is the high concentration of chloride ions, which makes the treatment difficult. It is also a problem that is difficult to solve. At present, the evaporation crystallization process and the flue evaporation process adopted by most enterprises have the problems of high investment cost and operation cost. The flue evaporation process also has the problem of corrosion of dust removal equipment by high-salt fly ash. , there are certain safety hazards, and the above two methods cannot achieve low-cost and low-input production and operation

[0018] In addition, the removal of chlorine ions by conventional ion exchange resins is suitable for use when the salinity of the solution is low. When the chloride ion concentration is below 1000mg / l, it is usually used to treat the product water after reverse osmosis treatment in the power plant environment, as a supplementary process for boiler feed water, but when the salinity increases and the chloride ion concentration is as high as 5000mg / l or more, the conventional ion The exchange resin cannot meet the needs. When it is barely used, the regeneration cycle of the resin is greatly reduced. The strong acid and alkali required for regeneration and the resulting high waste treatment and operating costs have become the biggest problems in use.

Images