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Method for resourceful treatment of cadmium-containing heavy metal wastewater

A heavy metal and resource-based technology, applied in chemical instruments and methods, multi-stage water treatment, water/sewage treatment, etc., can solve the problems of cumbersome and lengthy treatment processes, failure to meet environmental protection requirements, waste, etc., and achieve obvious economic benefits and Environmental benefits, solve the problem of heavy metal treatment, the effect of less additives

Inactive Publication Date: 2021-03-02
SHAANXI RES DESIGN INST OF PETROLEUM CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the conventional treatment method is chemical flocculation, which mainly involves adding a large amount of lime, caustic soda, flocculant, and heavy metal scavenger for treatment. costly
At the same time, a large amount of cadmium metal was wasted, which caused great waste. The current treatment method still cannot meet the environmental protection requirements.

Method used

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  • Method for resourceful treatment of cadmium-containing heavy metal wastewater
  • Method for resourceful treatment of cadmium-containing heavy metal wastewater

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] 1. Add precipitant ammonium carbonate to the deplating wastewater of cadmium-containing plating parts in a factory according to the molar ratio of precipitant to cadmium ion 1.20:1, and wash the precipitate with 0.01mol / L nitric acid aqueous solution, which can be used for repeated washing . The precipitate after washing with nitric acid aqueous solution was rinsed with clear water, filtered, moved into a quartz crucible, and heat-treated in a muffle furnace. The heat-treatment temperature was controlled to be 550° C., and the treatment time was 3 hours. After heat treatment, close the furnace and cool naturally to obtain high-purity cadmium oxide. Cadmium oxide is used to make cyanide cadmium plating solution.

[0022] 2. Pump the supernatant after precipitation in step 1 into the electrocoagulation device to remove heavy metal ions. The electrocoagulation device plate is aluminum plate, the plate thickness is 3mm, the distance between the plates is 20mm, and the curr...

Embodiment 2

[0025] 1. Add precipitant sodium carbonate to the deplating wastewater of cadmium-containing plating parts in a factory according to the molar ratio of precipitant to cadmium ion 1.20:1, and wash the precipitate with 0.01mol / L nitric acid aqueous solution, which can be used for repeated washing. The precipitate after washing with nitric acid aqueous solution was rinsed with water, filtered, moved into a quartz crucible, and subjected to heat treatment in a muffle furnace. The heat treatment temperature was controlled at 600°C and the treatment time was 1 hour. After heat treatment, close the furnace and cool naturally to obtain high-purity cadmium oxide. Cadmium oxide is used to make cyanide cadmium plating solution.

[0026] 2. Pump the supernatant after precipitation in step 1 into the electrocoagulation device to remove heavy metal ions. The electrode plate of the electrocoagulation device is aluminum plate, the thickness of the plate is 5mm, the distance between the plates...

Embodiment 3

[0029] 1. Add precipitant ammonium carbonate to the deplating wastewater of cadmium-containing plating parts in a factory according to the molar ratio of precipitant to cadmium ion 1.10:1, and wash the precipitate with 0.01mol / L nitric acid aqueous solution, which can be used for repeated washing. The precipitate after washing with nitric acid aqueous solution was rinsed with water, filtered, moved into a quartz crucible, and subjected to heat treatment in a muffle furnace. The heat treatment temperature was controlled at 500° C., and the treatment time was 2 hours. After heat treatment, close the furnace and cool naturally to obtain high-purity cadmium oxide. Cadmium oxide is used to make cyanide cadmium plating solution.

[0030] 2. Pump the supernatant after precipitation in step 1 into the electrocoagulation device to remove heavy metal ions. The electrode plate of the electrocoagulation device is aluminum plate, the thickness of the plate is 4mm, the distance between the ...

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Abstract

The invention discloses a method for resourceful treatment of cadmium-containing heavy metal wastewater, which comprises the following steps: adding a precipitant into cadmium-containing wastewater togenerate cadmium carbonate precipitate aiming at cadmium plating layer stripping solution wastewater, washing the cadmium salt precipitate, filtering, and carrying out heat treatment to thermally decompose cadmium carbonate to generate cadmium oxide which is used for preparing cyaniding cadmium plating solution for continuous resourceful utilization; after precipitation, removing heavy metal ionsin a supernatant through electric flocculation, and recycling electric flocculation produced water or partially discharging as cadmium-containing plating piece stripping mother liquor; performing electric flocculation treatment on acidic wastewater generated by nitric acid washing and filtering to remove heavy metal ions and then discharging after reaching the standard. According to the method, the cadmium element and the wastewater in the cadmium-containing wastewater are recycled, the purpose of recycling is achieved, the amount of hazardous waste sludge is reduced, the operation cost is low, the problem of heavy metal treatment is solved, and the method has obvious economic benefits and environmental protection benefits.

Description

technical field [0001] The invention belongs to the technical field of sewage treatment, and in particular relates to a heavy metal recovery and resource utilization technology in cadmium-containing heavy metal wastewater and a sewage reuse method. Background technique [0002] Heavy metal wastewater mainly comes from non-ferrous metal smelting, electroplating, leather processing and some chemical enterprises, etc. Cadmium-containing wastewater is one of the most harmful heavy metal wastewater. Although metal cadmium has no pathological significance, cadmium compounds are very toxic. Cadmium-containing wastewater is highly toxic, and cadmium is easy to accumulate in organisms. If it is discharged directly without treatment, it will easily cause chronic poisoning of humans and animals, and bring great harm to the environment. [0003] Both cadmium coating and zinc coating are widely used as the atmospheric protection layer of steel, especially in humid atmosphere and marine ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/06C01G11/00C02F101/20
CPCC02F9/00C01G11/00C02F1/62C02F1/463C02F2001/46133C02F2201/4614C02F2201/4615C02F1/66C02F2101/20C02F2301/08C02F2209/06
Inventor 张国辉朱瑞龙王玲燕姚彬张文存
Owner SHAANXI RES DESIGN INST OF PETROLEUM CHEM IND
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