Electroplating chromium-containing wastewater resourceful treatment method based on interface coordination regulation and control

Abstract

The invention discloses an electroplating chromium-containing wastewater resourceful treatment method based on interface coordination regulation, which comprises the following steps: crushing, grinding and floating natural magnetite and natural lead oxide ore, and roasting to obtain modified magnetite and modified lead oxide ore; then adding the modified magnetite into the electroplating chromium-containing wastewater to generate a precipitate A and a filtrate A; adding the filtrate A into the modified lead oxide ore to obtain a precipitate B and filtrate B; adding water into the precipitate B, introducing a sulfate or / and carbonate solution, and filtering to obtain a precipitate C and a filtrate C; and cooling the filtrate C to room temperature, separating out chromate crystals, filtering to obtain chromate precipitates, and drying and recovering the chromate precipitates. According to the method, the trivalent chromium and the hexavalent chromium are respectively treated by utilizing the characteristics of the trivalent chromium and the hexavalent chromium, so that the purposes of deep purification of the chromium-containing wastewater and resource recovery of chromium are achieved, the resource treatment of the chromium-containing wastewater is realized, and the method is high in chromium removal rate, low in production cost, simple to operate, environment-friendly and suitable for industrial application.

Description

technical field [0001] The invention relates to the field of environmental technology, in particular to a method for recycling electroplating chromium-containing wastewater based on interface coordination regulation. Background technique [0002] Chromium and its compounds are important chemical raw materials, widely used in metallurgy, electroplating, steel rolling, tanning, pharmaceutical and other industries, and produce a large amount of chromium-containing wastewater in the production process. Hexavalent chromium is toxic, strong oxidizing, migratory, and carcinogenic, and poses a threat to the environment and human health. Trivalent chromium poses a huge threat to aquatic organisms and can be oxidized to hexavalent chromium in the environment. Therefore, industrial wastewater Chromium removal is a problem that must be solved. [0003] At present, the treatment methods of electroplating chromium-containing wastewater include reduction precipitation method, adsorption m...

AI Technical Summary

Problems solved by technology

Hexavalent chromium is toxic, strong oxidizing, migratory, and carcinogenic, and poses a threat to the environment and human health. Trivalent chromium poses a huge threat to aquatic organisms and can be oxidized to hexavalent chromium in the environment. Therefore, industrial wastewater Chromium removal is a problem that must be solved

This method is currently the most widely used method for treating chromium-containing wastewater, but this method will generate a large amount of sedimentation sludge, occupy a large amount of land, and the chromium in the sludge is easy to leach, causing secondary pollution

The adsorption method includes physical adsorption, chemical adsorption and ion exchange adsorption. The hexavalent chromium is adsorbed and enriched on the adsorbent or resin by using an adsorbent or resin, and then undergoes desorption treatment to obtain a chromium-containing enrichment solution. It can be reused after attached treatment, and it is effective in treating low-concentration heavy metal wastewater. However, the adsorbent and resin are expensive, and are easily poisoned by heavy metals. The reaction time is long and the treatment cost is high.

The electrocoagulation method dissolves the anode by applying an electric field to generate metal hydroxide, and adsorbs and precipitates or co-precipitates the chromium in the wastewater. This method has a good treatment effect, but the anode is generally made of iron or aluminum, and the direct current will make the surface of the electrode blunt. The processing efficiency is affected, and the demand for electric energy is large, which restricts the widespread use of this method

The electrodialysis method uses the selective permeability of the membrane to move different ions in the wastewater to a certain electrode chamber for enrichment under the drive of the voltage. This method does not need to consume electrodes and does not produce precipitation, and the treatment effect is better Good, but the price of the membrane is high, and it is not economical to use in general wastewater treatment

[0004] Chinese patent document CN112028336A adopts reduction method to reduce hexavalent chromium to trivalent chromium, and then utilizes sodium hydroxide to adjust pH so that trivalent chromium generates Cr(OH) 3 Sedimentation, and then use the flotation method to deeply remove pollutants such as chromium hydroxide, grease and phosphorus in the wastewater, but the chromium-containing slag obtained by this method has limited uses

[0005] Chinese patent literature CN1373094A utilizes the solution containing lead ion to process waste water containing hexavalent chromium, with chrome yellow (PbCrO 4 ) form to recover hexavalent chromium, but lead-containing wastewater is produced, which needs further treatment

[0006] To sum up, the current treatment technologies for electroplating chromium-containing wastewater have disadvantages such as large amount of sedimentation, serious secondary pollution, high production costs, and difficult recovery of chromium resources.

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