Imidazole-containing chemical silver plating wastewater treatment system and method thereof

Abstract

The invention relates to an imidazole-containing chemical silver plating wastewater treatment system, which comprises an imidazole-containing chemical silver plating wastewater collection tank, a Fenton catalytic oxidation device, a physicochemical reaction precipitation device, a temporary storage tank and a resin adsorption device which are sequentially arranged along the flow direction of wastewater, the Fenton catalytic oxidation device comprises an oxidation pond; the physicochemical reaction precipitation device comprises a reaction tank, a coagulation tank and a precipitation tank whichare sequentially arranged in the flow direction of the wastewater, an inlet of the reaction tank is communicated with an outlet of the oxidation tank, and an outlet of the precipitation tank is communicated with an inlet of the temporary storage tank to collect precipitated a supernatant; the resin adsorption device comprises a sand filter tower, an activated carbon tower, a precision filter, ananion exchange resin tower and a chelating ion exchange resin tower which are sequentially arranged along the flow direction of the wastewater; and an inlet of the sand filter tower is communicated with an outlet of the temporary storage tank. The concentration of mercury ions passing through the treatment system can be stably lower than 0.1 mg/l. The invention also provides a method for treatingwastewater by adopting the imidazole-containing chemical silver plating wastewater treatment system.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a system and method for treating imidazole-containing chemical silver plating wastewater. Background technique [0002] With the development of electronics and electroplating industrial technology, a large number of chemicals such as sulfuric acid, silver nitrate, and organic solvents are used, making the discharged silver-containing wastewater a difficult point in wastewater treatment technology. Silver belongs to the first category of pollutants, and direct discharge to water will seriously pollute the ecological environment and threaten human health. [0003] The following process is usually used for the treatment of imidazole-containing chemical silver plating wastewater in the electronics industry (including the circuit board industry): (1) Add iron salt, liquid caustic soda, sodium sulfide, PAC, and PAM to react and precipitate in sequence by physic...

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Problems solved by technology

However, due to the unstable water quality of silver-containing wastewater entering the system, the amount of chelating agent has a great impact on the concentration of precipitated mercury ions, and it is difficult to achieve <0.1mg / l

(2) Resin absorption method: The resin absorption method introduced by existing documents or patents usually adopts macroporous cation exchange resin or anion exchange resin, but because the imidazole-containing chemical silver plating wastewater contains a large amount of chelating agent and nitrate, the simple use Anion exchange resin or cation exchange resin, the treatment effect is not very satisfactory

(3) Membrane separation method: The membrane treatment process introduced by existing documents or patents usually adopts ultrafiltration membrane, RO membrane filtration, etc., because the chemical silver plating wastewater containing imidazole contains a large amount of chelated organic matter and nitrate, which is easy to cause membrane blockage , nitrate has certain oxidizing properties, which will cause certain damage to the membrane. At the same time, the concentrated silver-containing waste liquid also needs to be treated by a professional unit, and the treatment cost is relatively high.

(5) Electrolysis method: The electrolysis method introduced in existing literature or patents is usually used for the recycling of high-concentration silver-containing waste liquid, and low-concentration waste water is of little value, and the effluent cannot reach <0.1mg / l

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