Processing method of wastewater desulfurized by fume wet method

Abstract

The invention relates to a processing method of wastewater desulfurized by a fume wet method. The processing method of the wastewater desulfurized by the fume wet method is characterized by comprising the following steps of: (1) inputting the wastewater desulfurized by the fume wet method into a pH value regulation tank, regulating the pH value, adding soluble sulfide, a flocculating agent water solution and a coagulant aid water solution, flocculating, clarifying, standing, stratifying, burying silt after filtering, regulating the pH value again, flocculating, clarifying, standing, stratifying and processing a solid after filtering a precipitation bed; (2) preprocessing supernatant liquid after standing and stratifying in the tank, introducing the purified flue gas under a stirring condition after inputting into a softening tank, stopping introducing the flue gas until the pH is 9-10, then stirring continuously, standing and stratifying; and (3) evaporating and concentrating clear liquid after standing and stratifying in the softening tank. The invention can recycle resources circularly and achieves zero discharge truly; and the method for introducing the flue gas in the invention has little use dose and low cost and has the function of lowering carbon discharge.

Description

technical field

[0001] The invention belongs to the technical field of waste water treatment, and in particular relates to a treatment method for waste water from flue gas wet desulfurization by "limestone / lime-gypsum method". Background technique

[0002] "Limestone / lime-gypsum method" flue gas desulfurization technology can efficiently remove SO in flue gas 2 , and has the characteristics of high system reliability, and is currently the most widely used method in flue gas desulfurization projects in thermal power plants. Desulfurization by this method will produce a small amount of wastewater, and the wastewater generated during the wet desulfurization of boiler flue gas (limestone / lime-gypsum method) comes from the discharge water of the absorption tower. In order to maintain the balance of substances in the slurry circulation system of the desulfurization unit, prevent the soluble part of the flue gas, that is, the concentration of chloride ions from exceeding the speci...

Examples

Embodiment 1

[0038] A treatment method for flue gas wet desulfurization waste water, it comprises the steps:

[0039] 1) Take the wastewater discharged from the desulfurization system of a certain power plant (that is, the waste water from flue gas wet desulfurization). After testing, its main components are as follows:

[0040] 1. pH: 5.3 2. SS: 11300mg / L

[0041] 3. Chloride ion: 13500mg / L 4. Sulfate radical: 4800mg / L

[0042] 5. Calcium ion: 1600mg / L 6. Magnesium ion: 1800mg / L

[0043] 7. Fluoride ion: 120mg / L 8. Sodium ion: 5800mg / L

[0044] 9. COD Cr : 195mg / L 10, Zn: 10mg / L

[0045] 11. Hg: 1mg / L 12. Cd: 3mg / L

[0046] 13. Cr: 2mg / L 14. Pb: 5mg / L

[0047] 15. Ni: 1mg / L 16. Cu: 15mg / L

[0048] 17. Fe: 3mg / L

[0049] Determine the amount of soluble sulfide (sodium sulfide) and soluble sulfate (sodium sulfate) according to the water quality components, that is, the amount of sodium sulfide added per liter of wastewater is 20 mg, and the amount of sodium sulfate added is 20 grams...

Embodiment 2

[0068] A treatment method for flue gas wet desulfurization waste water, it comprises the steps:

[0069] 1) Preparation of raw materials: choose sodium sulfide for soluble sulfide; choose sodium sulfate for soluble sulfate; choose ferric chloride as flocculant to make flocculant aqueous solution; choose polyacrylamide as coagulant aid to make coagulant aid aqueous solution ; The milk of lime is the milk of lime used by the desulfurization system; the dilute acid is dilute hydrochloric acid.

[0070] Flue gas wet desulfurization wastewater refers to the process of wet desulfurization (limestone / lime-gypsum method) of boiler flue gas. To specify the value and guarantee the quality of gypsum, the waste water discharged from the system.

[0071] Detect the hardness of calcium and magnesium in wet flue gas desulfurization wastewater (due to the difference in coal quality, the concentration of calcium and magnesium is generally 0.05mol / L), heavy metals (the content is generally 0.0...

Embodiment 3

[0078] A treatment method for flue gas wet desulfurization waste water, it comprises the steps:

[0079] 1) Preparation of raw materials: Sodium sulfide is used for soluble sulfide; sodium sulfate is used for soluble sulfate; ferric chloride is used as flocculant, and the flocculant aqueous solution is prepared. The coagulant aid is selected from polyacrylamide, which is made into an aqueous coagulant aid solution. The milk of lime is the milk of lime used by the desulfurization system. The dilute acid is dilute sulfuric acid.

[0080] Flue gas wet desulfurization wastewater refers to the process of wet desulfurization (limestone / lime-gypsum method) of boiler flue gas. To specify the value and guarantee the quality of gypsum, the waste water discharged from the system.

[0081] Detect the hardness of calcium and magnesium in wet flue gas desulfurization wastewater (due to the difference in coal quality, the concentration of calcium and magnesium is generally 0.5mol / L), heav...

technical field

[0001] The invention belongs to the technical field of waste water treatment, and in particular relates to a treatment method for waste water from flue gas wet desulfurization by "limestone / lime-gypsum method". Background technique

[0002] "Limestone / lime-gypsum method" flue gas desulfurization technology can efficiently remove SO in flue gas 2 , and has the characteristics of high system reliability, and is currently the most widely used method in flue gas desulfurization projects in thermal power plants. Desulfurization by this method will produce a small amount of wastewater, and the wastewater generated during the wet desulfurization of boiler flue gas (limestone / lime-gypsum method) comes from the discharge water of the absorption tower. In order to maintain the balance of substances in the slurry circulation system of the desulfurization unit, prevent the soluble part of the flue gas, that is, the concentration of chloride ions from exceeding the speci...

Examples

Embodiment 1

[0038] A treatment method for flue gas wet desulfurization waste water, it comprises the steps:

[0039] 1) Take the wastewater discharged from the desulfurization system of a certain power plant (that is, the waste water from flue gas wet desulfurization). After testing, its main components are as follows:

[0040] 1. pH: 5.3 2. SS: 11300mg / L

[0041] 3. Chloride ion: 13500mg / L 4. Sulfate radical: 4800mg / L

[0042] 5. Calcium ion: 1600mg / L 6. Magnesium ion: 1800mg / L

[0043] 7. Fluoride ion: 120mg / L 8. Sodium ion: 5800mg / L

[0044] 9. COD Cr : 195mg / L 10, Zn: 10mg / L

[0045] 11. Hg: 1mg / L 12. Cd: 3mg / L

[0046] 13. Cr: 2mg / L 14. Pb: 5mg / L

[0047] 15. Ni: 1mg / L 16. Cu: 15mg / L

[0048] 17. Fe: 3mg / L

[0049] Determine the amount of soluble sulfide (sodium sulfide) and soluble sulfate (sodium sulfate) according to the water quality components, that is, the amount of sodium sulfide added per liter of wastewater is 20 mg, and the amount of sodium sulfate added is 20 grams...

Embodiment 2

[0068] A treatment method for flue gas wet desulfurization waste water, it comprises the steps:

[0069] 1) Preparation of raw materials: choose sodium sulfide for soluble sulfide; choose sodium sulfate for soluble sulfate; choose ferric chloride as flocculant to make flocculant aqueous solution; choose polyacrylamide as coagulant aid to make coagulant aid aqueous solution ; The milk of lime is the milk of lime used by the desulfurization system; the dilute acid is dilute hydrochloric acid.

[0070] Flue gas wet desulfurization wastewater refers to the process of wet desulfurization (limestone / lime-gypsum method) of boiler flue gas. To specify the value and guarantee the quality of gypsum, the waste water discharged from the system.

[0071] Detect the hardness of calcium and magnesium in wet flue gas desulfurization wastewater (due to the difference in coal quality, the concentration of calcium and magnesium is generally 0.05mol / L), heavy metals (the content is generally 0.0...

Embodiment 3

[0078] A treatment method for flue gas wet desulfurization waste water, it comprises the steps:

[0079] 1) Preparation of raw materials: Sodium sulfide is used for soluble sulfide; sodium sulfate is used for soluble sulfate; ferric chloride is used as flocculant, and the flocculant aqueous solution is prepared. The coagulant aid is selected from polyacrylamide, which is made into an aqueous coagulant aid solution. The milk of lime is the milk of lime used by the desulfurization system. The dilute acid is dilute sulfuric acid.

[0080] Flue gas wet desulfurization wastewater refers to the process of wet desulfurization (limestone / lime-gypsum method) of boiler flue gas. To specify the value and guarantee the quality of gypsum, the waste water discharged from the system.

[0081] Detect the hardness of calcium and magnesium in wet flue gas desulfurization wastewater (due to the difference in coal quality, the concentration of calcium and magnesium is generally 0.5mol / L), heav...