SU1214613A1 - System for purifying electroplating sewage - Google Patents

Description

one

The invention relates to the reagent treatment of industrial wastewater and is intended for use in sewage treatment plants of industrial enterprises.

The purpose of the invention is to reduce the volume of the forming precipitate and reduce its power.

The drawing shows a diagram of a plant for the treatment of wastewater from electroplating plants.

The installation contains reactor 1 for the reduction of chromates, to the inlet of which a pipeline of 2 chrome-washing wastes is supplied. The outlet of the chromate reduction reactor 1 is connected by a discharge pipe 3 to the common flow neutralization reactor 4. The pipeline 5 from the measuring device 6 acids and the outlet pipe 7 from the reducing agent dispenser 8, on which the control valve 9 is installed, are also connected to the chromate recovery reactor 1. The control valve 10 is installed on the pipeline 5.

The outlet pipe 11 is connected to the inlet of the 6-acid measuring device 11 from the accumulator 12 of chrome-concentrated and concentrated acid waste,

To the entrance of the accumulator 12 of chrome-concentrated and concentrated acidic effluent, pipeline 13, chromium-concentrated effluent, pipeline 14 of concentrated acidic effluent, and discharge pipeline 15 of the reducing agent dispenser 8 are connected.

The device also includes a cyanide oxidation reactor 16, to the inlet of which a cyanide wash line 17 is connected, to which an oxidizer metering pipe 18 is connected to the inlet, where a regulating valve 20 is installed and a lime milk dispensing pipe 21 21, where a regulating valve 23 is installed. A discharging pipe 24 of accumulator 25 of concentrated cyanides and concentrated alkaline effluents is connected to the milk milk metering unit. To the entrance of the accumulator 25 of concentrated cyanites and concentrated alkaline wastewaters, a pipeline of 26 concentrated cyanites, a pipeline of 27 concentrated alkaline wastewaters and a discharge pipeline 28 of an oxidizer batcher 19 are connected. Output pe132

The cyanide oxidation actor 16 is connected by a DRAINAGE OF CYTEM 29 by a pipe 29 to the inlet of a common runoff reactor 4, which is also connected to a milk milk dispenser 22 outlet pipe 30, on which a control valve 3 is installed and an acid measuring pipe 32 - set the control valve 33.

To the inlet of the reactor 4, the pipeline 34 of the washing acid-alkaline and paint-containing drains is also connected, and the outlet of the reactor 4 of the common drain is connected by a pipeline 35 to a sump.

The installation works as follows

Concentrated acidic effluent through conduit 14 and chrome-concentrated effluent via conduit 13 are fed to accumulator 12 and mixed. The resulting mixture has a strongly acidic reaction, since all concentrated solutions

electroplating, painting pro- | Manufacturing of printed circuit boards, including | In its composition chromates, contain large quantities of various acids, mainly sulfuric and nitric.

Concentrated acidic effluent contains various reducing agents. For example, in the treated steel etching solution, ferrous iron ions are contained, in the spent solution the coatings of tin-: bismuth-tin ions of divalent, in the spent solution, remove chromium ions of divalent chromium, etc. d.

When moving a mixture of these two types of concentrated effluent, some of the chromates are restored to the trivalent form. To the remaining part of the chromates in the accumulator 12, the reducing agent from the dispenser 8 is added through the pipeline 15. As a reducing agent, both commercial sulfate reagent, sodium bisulfite, ferrous sulphate and production waste can be used, for example, ferric chloride used in etching printed circuit boards. . This solution, which has exhausted its poisoning ability, accumulates up to 100 g / l of ferrous iron. After a slight excess has been restored in drive 12

and heavy metal ions 3+ about g

Vitep (5-10 mg / l), which indicates the end of the reaction for the reduction of chromates, its contents will be a mixture of acids (sulfuric, hydrochloric, nitric) (Fe Cr-t, etc.).

Then the contents of the storage tank 12 of the pipeline 11 are supplied to the measuring device 6 of acid, which is an intermediate tank, and through the outlet pipeline 5 is sent to the chromate recovery reactor 1,

Pipe wash 2 also receives chrome washings through the pipeline 2, and the mixture of acids from pipelines 5 is vigorously stirred.

After the reduction of the chromates, the stream through conduit 3 enters the neutralization reactor 4 in common with ka.

Concentrated cyanetic currents through conduit 26 and concentrated alkaline drains through conduit 27 are fed to accumulator 25. Concentrated cyanogen stocks contain up to 50-70 g / l of NaOH, heavy metal ions, such as zinc, copper, etc.

Concentrated alkaline drains contain NaOH, and some other components. The data obtained in the table shows that, while maintaining high rates of water quality, operation is pre-141313

The hopper 25, the mixture is the second main supplier of salts to the general stock.

Through line 28, oxidizer from dispenser 19 is added to storage tank 5 25 until its excess in the storage tank is approximately 5.0-10 mg / l. Then the concentrated effluent through pipe 2A is fed to

0 dispenser 22, where they are mixed with izvet stkovogo milk.

Wash cyansthea through pipeline 17 is fed to the cyanide oxidation reactor 16, After oxidation

15, the cyanide stream is directed through conduit 29 to the common runoff neutralization reactor 4. The effluent from the chromate reduction reactor 1, from the cyanide oxidation reactor 16,

2Q washings, acid-sink drains and paint-containing drains flow into the tank 4 of the neutralization of the total flow. After neutralization in the reactor 4, the total flow through the 25 ECT pipeline 35 is supplied to the standoff.

Comparative data on wastewater treatment of electroplating plants on the proposed and known 30 installations are presented in the table.

Lagged installation allows to reduce the volume of sediment and reduce its humidity.

Claims (1)

PLANT WASTE WATER TREATMENT PLANT, comprising a chromate reduction reactor, a common drain neutralization reactor, a chrome concentrated and concentrated acid effluent accumulator, a cyanide oxidation reactor, a concentrated cyanide and concentrated alkaline effluent accumulator, reducing agent dispensers. oxidizing agent, milk of lime and acid, moreover, the chromate reduction reactor through the control valve is connected to the reducing agent dispenser, the common drain neutralization reactor is connected to the chromate reduction reactor, the cyanide oxidation reactor and through the control valve to the lime milk dispenser, characterized in that, with In order to reduce the volume of the precipitate and reduce its moisture, the reducing agent dispenser is connected to the inlet of the chrome-concentrated and concentrated acidic wastewater, which yuschy valve connected to the inlet of the reactor and the reactor recovery chromate neutralization common drain, and storage of concentrated alkaline waste connected to the inlet of the dispenser of milk of lime. to ΜαιΑ hU with 1 I2