Method for treating resin production wastewater based on combination of chemical precipitation and two-stage photocatalysis

Abstract

The invention discloses a method for treating resin production wastewater based on combination of chemical precipitation and two-stage photocatalysis, relates to a method for treating the resin production wastewater, and aims to solve the technical problems that the existing resin production wastewater is high in treatment difficulty, large in medicament dosage, complicated in treatment process and high in secondary pollution and needs to be diluted when being used for treating high-concentration wastewater. The method comprises the following steps: 1, primary chemical precipitation; 2, secondary chemical precipitation; 3, carrying out primary photocatalytic reaction; and 4, carrying out secondary photocatalytic reaction. According to the method, the wastewater with the concentration of about 330000 mg / L can be treated to reach the standard without dilution, the effluent can stably reach 60 mg / L or below, the removal rate of COD reaches 99.97% or above, the COD emission standard in the emission standard of pollutants in the synthetic resin industry is met, and the method can be applied to the field of resin production wastewater treatment.

Description

technical field

[0001] The invention relates to a treatment method for resin production wastewater, belonging to the field of industrial wastewater treatment. Background technique

[0002] Resin production wastewater is mainly wastewater discharged during the production of various synthetic resins, such as alkyd resins, acrylic resins and unsaturated polyester resins, including reactor cleaning liquid and condensate in the condenser. The wastewater has the characteristics of high COD concentration, complex composition, high toxicity, bioaccumulation, long-term residual, etc., and the water quality changes greatly with the working conditions, which leads to many problems in its treatment, such as difficulty, poor effect, and high cost. Due to its strong pollution load, high acidity and complex composition, direct discharge will have a greater impact on the environment. And it emits a strong irritating odor, which is harmful to the senses. 2) The waste water is acidic, which...

Examples

Embodiment 1

[0022] Embodiment 1: The method for treating resin production wastewater based on chemical precipitation combined with two-stage photocatalysis in this embodiment is carried out according to the following steps:

[0023] 1. First-grade chemical precipitation: add calcium hydroxide solid to the resin production wastewater to make the calcium hydroxide concentration reach 1.0g / L, stir and react for 70min, a precipitate is formed, and stand for 12 hours to obtain a first-grade supernatant;

[0024] 2. Secondary chemical precipitation: continue to add sodium hydroxide solid to the primary supernatant, so that the pH of the primary supernatant reaches 7, a precipitate is formed, and let stand for 12 hours to obtain the secondary supernatant;

[0025] 3. Primary photocatalytic treatment: use UV / H 2 O 2 The secondary supernatant is treated by photocatalytic oxidation, that is, hydrogen peroxide with a mass percentage concentration of 30% is added to the secondary supernatant, and th...

Embodiment 2

[0028] Embodiment 2: The method for treating resin production wastewater based on chemical precipitation combined with two-stage photocatalysis in this embodiment is carried out according to the following steps:

[0029] 1. First-level chemical precipitation: add calcium hydroxide solid to the resin production wastewater to make the calcium hydroxide concentration reach 0.8g / L, stir and react for 90min, a precipitate is formed, and stand for 12 hours to obtain a first-level supernatant;

[0030] 2. Secondary chemical precipitation: continue to add sodium hydroxide solid to the primary supernatant, so that the pH of the primary supernatant reaches 8, and precipitate is formed, and let stand for 16 hours to obtain the secondary supernatant;

[0031] 3. Primary photocatalytic treatment: use UV / H 2 O 2 The secondary supernatant is treated by the photocatalytic oxidation method, that is, hydrogen peroxide with a mass percentage concentration of 30% is added to the secondary supern...

technical field

[0001] The invention relates to a treatment method for resin production wastewater, belonging to the field of industrial wastewater treatment. Background technique

[0002] Resin production wastewater is mainly wastewater discharged during the production of various synthetic resins, such as alkyd resins, acrylic resins and unsaturated polyester resins, including reactor cleaning liquid and condensate in the condenser. The wastewater has the characteristics of high COD concentration, complex composition, high toxicity, bioaccumulation, long-term residual, etc., and the water quality changes greatly with the working conditions, which leads to many problems in its treatment, such as difficulty, poor effect, and high cost. Due to its strong pollution load, high acidity and complex composition, direct discharge will have a greater impact on the environment. And it emits a strong irritating odor, which is harmful to the senses. 2) The waste water is acidic, which...

Examples

Embodiment 1

[0022] Embodiment 1: The method for treating resin production wastewater based on chemical precipitation combined with two-stage photocatalysis in this embodiment is carried out according to the following steps:

[0023] 1. First-grade chemical precipitation: add calcium hydroxide solid to the resin production wastewater to make the calcium hydroxide concentration reach 1.0g / L, stir and react for 70min, a precipitate is formed, and stand for 12 hours to obtain a first-grade supernatant;

[0024] 2. Secondary chemical precipitation: continue to add sodium hydroxide solid to the primary supernatant, so that the pH of the primary supernatant reaches 7, a precipitate is formed, and let stand for 12 hours to obtain the secondary supernatant;

[0025] 3. Primary photocatalytic treatment: use UV / H 2 O 2 The secondary supernatant is treated by photocatalytic oxidation, that is, hydrogen peroxide with a mass percentage concentration of 30% is added to the secondary supernatant, and th...

Embodiment 2

[0028] Embodiment 2: The method for treating resin production wastewater based on chemical precipitation combined with two-stage photocatalysis in this embodiment is carried out according to the following steps:

[0029] 1. First-level chemical precipitation: add calcium hydroxide solid to the resin production wastewater to make the calcium hydroxide concentration reach 0.8g / L, stir and react for 90min, a precipitate is formed, and stand for 12 hours to obtain a first-level supernatant;

[0030] 2. Secondary chemical precipitation: continue to add sodium hydroxide solid to the primary supernatant, so that the pH of the primary supernatant reaches 8, and precipitate is formed, and let stand for 16 hours to obtain the secondary supernatant;

[0031] 3. Primary photocatalytic treatment: use UV / H 2 O 2 The secondary supernatant is treated by the photocatalytic oxidation method, that is, hydrogen peroxide with a mass percentage concentration of 30% is added to the secondary supern...

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