RU141949U1 - DEVICE FOR WASTE WATER TREATMENT FOR PRODUCTION OF PRINTED CIRCUIT BOARDS CONTAINING ALCOHOLIC PHOTO RESIST SPF-VSC - Google Patents

Abstract

A device for treating wastewater from the production of printed circuit boards containing an SPF-VSC water-alkaline photoresist, comprising a housing with an electroflotation chamber and an electrolyzer in it in the form of an anode and two side cathode chambers, characterized in that the side cathode chambers of the electrolyzer are equipped with nozzles for introducing and discharging sewage water and pipelines connecting them to the anode chamber, while inside the side cathode chambers an additional cation exchange membrane and anode are placed.

Description

The proposed utility model relates to devices for wastewater treatment for the production of printed circuit boards containing a water-alkaline photoresist SPF-VSC.

A device is known that contains a housing with an electrolyzer placed in it, the anode chamber of which is located between the symmetric cathode chambers, and the electroflotation chamber [RF Patent No. 2067555 C1 IPC ⁶ C02F 1/46, 1/465. The wastewater treatment method for the production of printed circuit boards containing a water-alkaline photoresist type SPF-VSC, and a device for its implementation; declared 04/28/1993; publ. 10/10/1996].

The disadvantage of this device is the low productivity of the processes of membrane electrolysis, due to the small area of the electrodes and membranes.

It is known that a device containing a housing, selected as a prototype, is equipped with an electroflotation chamber and an electrolyzer in the form of an anode and two lateral cathode chambers [Utility Model Patent of the Russian Federation No. 133120 U1 IPC C02F 1/46. A device for treating wastewater from the production of printed circuit boards containing a water-alkaline photoresist SPF-VSC; declared 03/28/2013; publ. 10/10/2013. Bull. 28].

The disadvantage of this device is the insufficient productivity of the processes of membrane electrolysis, due to the small area of the electrodes and membranes.

The technical problem and the result, which is aimed by the claimed device for wastewater treatment for the production of printed circuit boards containing water-alkaline photoresist SPF-VSC, is to increase the productivity of membrane electrolysis processes.

The technical result is achieved by the fact that the device includes a housing with an electroflotation chamber and an electrolyzer in the form of an anode and two side cathode chambers. According to the proposed utility model, the side cathode chambers of the electrolyzer are equipped with nozzles for input and output of wastewater and pipelines connecting them to the anode chamber, while a cation exchange membrane and an anode are additionally placed inside the side cathode chambers.

The proposed utility model of the device is illustrated in the figure, where in FIG. 1 is a top view.

The device consists of a housing 1, separated by an overflow partition 2 into an electrolyzer 3 and an electroflotation chamber 4. The electrolyzer is made in the form of an anode 5 and two side cathode chambers 6.

The anode chamber is separated from the cathode by cation exchange membranes 7.

Plate insoluble anodes 8 are installed in the anode chamber, which are located at an angle relative to the cathodes with alternating lateral and central gaps for the flow of wastewater.

Inside the cathode chambers of the electrolyzer are located cation exchange membranes 9, forming the anode sections 10.

In the cathode chambers installed plate insoluble cathodes 11 and anodes 12.

The anode chamber is equipped with nozzles 13 for introducing acidified wastewater.

The cathode chambers are equipped with nozzles for input 17 and output 18 of alkaline water (catholyte), nozzles for input of alkaline wastewater 14 and output acidified wastewater 15 and pipelines 16 connecting them to the anode chamber.

In the electroflotation chamber, horizontal insoluble electrodes 19 (cathodes and anodes) are placed in the form of a comb and there are nozzles 20 for removing purified water. From the end of the electroflotation chamber opposite from the electrolyzer there is a foam collector 21.

In the upper part of the device located above the water level, there is a foam collecting device 22, driven by a gear motor 23.

The device operates as follows. Alkaline wastewater containing a water-alkaline photoresist SPF-VSC enters through the nozzles 14 into the anode sections 10 of the lateral cathode chambers 6 of the electrolyzer, in which, under the action of a current load, insoluble anodes 12 undergo an electrochemical anodic reaction of the discharge of hydroxyl ions with the formation of gaseous oxygen and water molecules (4OH ^- → O ₂ + 2H ₂ O). The acidified wastewater then flows through pipelines 16 into the anode chamber 5 of the electrolyzer, in which, under the influence of a current load, the anode 8 undergoes an electrochemical anode reaction to discharge water molecules with the formation of gaseous oxygen and hydrogen ions (2H ₂ O → O ₂ + 4H ⁺ ), due to whereby the pH of the wastewater decreases (acidifies) to a pH of 2-4, at which the formation of particles of the dispersed phase of the photoresist and their flotation with oxygen bubbles proceed.

Simultaneously, in the lateral cathode chambers 6, when water molecules are discharged on the surface of the insoluble cathodes 11, hydrogen gas is released and water is alkalized due to the formation of hydroxyl ions OH ^- .

The separation of the products of the anodic and cathodic reactions by cation exchange membranes 7 and 9 suppresses the transport of OH ^- and H ⁺ ions in the volume of the treated water and their chemical interaction with the formation of water molecules.

Further, wastewater containing particles of the dispersed phase of the SPF-VSC photoresist is poured through the baffle 2 and enters the electroflotation chamber 4, in which under the influence of gas bubbles (hydrogen and oxygen) formed on insoluble electrodes (anodes and cathodes) 19 during water electrolysis , there is a process of separation of wastewater and particles of the dispersed phase of the photoresist. Purified water is discharged from the device through nozzles 20.

The dispersed phase of the photoresist that has surfaced during electroflotation onto the water surface is formed into foam, which is removed by the foam collecting device 22 into the foam collector 21 and then removed from the device.

, Кл/л), которая может быть определена по формуле [Яковлев С.В., Краснобородько И.Г., Рогов В.М. Технология электрохимической очистки воды. - Л.: Стройиздат, 1987. С. 289-291.]An increase in the productivity of membrane processes is achieved due to the additional placement of anodes and cation-exchange and membranes in the lateral cathode chambers, which increases the total working surface area of their surface in the cell. In this case, the productivity of the process or installation (Q, m ³ / h) will be determined by the change in pH (alkalinity) of the treated water. The main calculated value for the required change in pH in the working anode chamber is the current consumption (

, CL / l), which can be determined by the formula [Yakovlev S.V., Krasnoborodko I.G., Rogov V.M. Technology of electrochemical water treatment. - L .: Stroyizdat, 1987. S. 289-291.]

,

,

- удельное изменение кислотности на 100 Кл/л, мг-экв/л.where K _To and K _N - the required final and initial acidity of water, respectively;

- specific change in acidity per 100 C / l, mEq / L.

The performance of the process will be

,

,

where S _e - the surface area of the electrodes; i _e - current density at the electrodes.

Thus, with an increase in the surface area of the electrodes, the productivity of the process will increase.

The productivity of the process is also influenced by the rate of ion transfer through the membrane, determined by the magnitude of the change in ion concentration (C _ref / C _con ), which can be calculated by the formula [Bogatyrev A.E., Vartsov V.V., Shulpin G.P. Membrane electrodialysis technologies for electroplating. Issue 3 (1697). - M.: Central Research Institute "Electronics", 1993. - S. 57.]:

,

,

where D is the diffusion coefficient of ions; δ is the thickness of the limiting diffusion layer; S _mb - membrane area; i _mb is the current density on the membrane; W _n - linear flow rate of the treated water along the membranes.

Thus, with an increase in the membrane area, the productivity of the process (mass transfer rate) will also increase.

The technical result in solving the problem is achieved by increasing the total working surface area of the cation exchange membranes and anodes.

The proposed design of a wastewater treatment device for the production of printed circuit boards containing a water-alkaline photoresist SPF-VSh, can improve the performance of membrane electrolysis processes.

Claims (1)

A device for wastewater treatment for the production of printed circuit boards containing an SPF-VSC water-alkaline photoresist, comprising a housing with an electroflotation chamber and an electrolyzer in it in the form of an anode and two side cathode chambers, characterized in that the side cathode chambers of the electrolyzer are equipped with nozzles for input and output of the wastewater water and pipelines connecting them to the anode chamber, while a cation exchange membrane and anode are additionally placed inside the lateral cathode chambers.

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