JPS60197293A - Apparatus for treating fluorine-containing waste water - Google Patents

Abstract

PURPOSE:To stably obtain treated water quality in low cost, by mounting an operator for operating the amount to be added of chemicals on the basis of detection values of a fluorine meter is a pH meter and an apparatus for controlling a chemicals adding means for adding chemicals in the operated addition amount. CONSTITUTION:A pH meter 26 is arranged to a reaction tank 12 and the output value thereof is inputted to an operation part 21. The amounts of aluminum salt and a neutralizing agent to be added is operated on the basis of values of a flow meter 18, a fluorine meter 19 and the pH meter 26 in an operation part 2 and the operated result is outputted to a control part 22. The control part 22 issues a signal for regulating the opening degrees of valves 33, 34 provided to pipings 13, 14 so as to secure the addition amount calculated in an operation part 24. Furthermore, an aluminum salt solution supply mechanism 43 consisting of a dissolving tank of chemicals and a chemical solution supply pump for transferring the solution in the dissolving tank to the pipings 13, 14 and a neutralizing solution supply mechanism 44 are arranged to the upstream pipe of the pipings 13, 14.

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to the treatment of fluorine-containing wastewater III, and particularly relates to a treatment device that removes fluorine by adding fluorine-containing wastewater treatment chemicals such as flocculants to raw water to be treated. It is something.

[Background of the invention] Aluminum electrolytic refining process, semiconductor etching process,
Fluorine-containing wastewater is discharged from various processes such as cathode ray tube cleaning processes.

As one of such fluorine-containing wastewater treatment devices, there is a device that removes fluorine by adding a flocculant (for example, an aluminum salt such as PAC1 sulfuric acid band). Therefore, when treating fluorine-containing wastewater using a flocculant, it is important to adjust the pH of the raw water to be treated within a specified range in order to increase treatment efficiency, and when using a flocculant whose main component is aluminum salt. Usually, the pH of the liquid to be treated is maintained in a neutral range.

FIG. 1 is a schematic system diagram showing a conventional example of an apparatus for treating fluorine-containing wastewater using aluminum salt.

In this conventional device, the wastewater to be treated (raw water) is introduced into the inlet pipe.
is introduced into the reaction tank 2. Then, aluminum salt and a neutralizing agent are added and mixed through an aluminum salt supply pipe 3 and a neutralizing agent (for example, crystalline soda, slaked lime, etc.) supply pipe 4 (8 is a stirring device for mixing), and then into a reaction tank. After reacting in 1 reaction tank 2, it is introduced into a solid-liquid separation tank 7 for solid-liquid separation treatment.A pH meter 5 is installed in the 0 reaction tank 2, so that the reaction liquid in the 1 reaction tank 2 becomes almost neutral. The amount of neutralizing agent added is adjusted by changing the opening degree of valve 6. Note that 9 dissolves the neutralizing agent and connects it to pipe 4.
It is a mechanism that feeds the

However, in such conventional equipment, the amount of aluminum salt added is set to a fixed amount, and this amount is adjusted at maximum load, that is, between the raw water flow rate and the raw water flow rate, in order to prevent fluorine from leaking into the treated water. The amount of addition is set at the amount required when the product of the fluorine concentration and the fluorine concentration reaches a general value. Therefore, the amount of aluminum salt added becomes excessive when the maximum load is applied, and when the flow rate and water quality fluctuate greatly, the amount of aluminum salt added becomes considerably excessive. Furthermore, if a load greater than the predicted maximum load is applied due to various reasons, there is a risk that fluorine will leak into the treated water.

[Summary of Prologue 1] The purpose of the present invention is to solve the above-mentioned problems of the conventional technology, eliminate excessive addition of chemicals, reduce treatment costs, and provide a fluorine-containing solution that can provide extremely stable treated water quality. An object of the present invention is to provide a treatment device for wastewater containing wastewater.

[Structure of the Invention] In order to achieve this object, the fluorine-containing wastewater treatment device of the present invention introduces IK water into a reaction tank, adds and mixes a fluorine-containing wastewater treatment chemical, and then transfers the IK water to a solid-liquid separation means. In the equipment introduced to remove fluorine from wastewater through solid-liquid separation, it detects the flow rate of raw water, fluorine concentration, and pH in the reaction tank, and calculates the required amount of chemicals to be added based on these detected values. It is configured to be added.

[Embodiments of the invention] Examples will be described below.

FIG. 2 is a system diagram of the apparatus of the unexposed 153 embodiment.

In this example device, raw water is supplied to the inlet pipe 1. t into the reaction tank 12°. From pipes 13 and 14, aluminum 11 such as polyaluminum chloride and aluminum sulfate, etc.
A neutralizing agent such as slaked lime, caustic soda, etc. is supplied to the reaction tank 12, and the raw water, aluminum salt, and neutralizing agent are sufficiently mixed and reacted by the air blown into the bottom of the tank by the blower 15. This reaction liquid is introduced into the solid-liquid separation tank 16, the supernatant liquid is discharged from the pipe 17 as treated water, and the precipitate is removed from the WI
It is pulled out from the bottom of 16.

The introduction pipe 11 is equipped with a flowmeter 18. A fluorine cumulative total 19 is installed to detect the raw water flow rate and the fluorine concentration in the raw water and output it to the calculation section 21 of the calculation controller 20.

A pH meter 26 is also installed in the reaction tank 12, and its output value is input to the calculation section 21. The calculation section 21 calculates the amounts of aluminum salt and neutralizing agent to be added based on the output values of the flow meter 18, the fluorocarbon total 19, and the PH meter 26, and outputs the calculation results to the control section 22. The control unit 22 issues a signal to adjust the opening degree of the valve 33.34 provided in the pipe 13.14 so that the addition amount determined by the calculation unit 21 is achieved. Note that there is a chemical dissolution tank in the upstream part of piping 13 and 14, and the dissolution tank i
An aluminum salt solution supply mechanism 43.t consisting of a chemical solution supply pump and the like that sends the solution of t to piping 13.14. A neutralizing agent liquid feeding mechanism 44 is installed.

In this way, the amount of aluminum salt and neutralizing agent added is controlled according to the flow rate of raw water, fluorine concentration, and pH in the reaction tank, so problems such as fluorine leakage due to excessive addition of chemicals or insufficient addition of chemicals can be avoided. will be resolved.

In addition, in this embodiment, the treated water discharge pipe 17 also has a cumulative total of 25
is provided, and its output value is input to the calculation section 21. The calculation unit 21 is configured to be able to correct the above calculation result depending on the fluorine concentration in the treated water (for example, when the fluorine concentration in the treated water exceeds a predetermined value).

Since the device shown in FIG. 2 is an embodiment of the present invention, the invention is not limited to the device of the above embodiment.

For example, the added chemical may be a flocculant other than aluminum salt or a fluorine adsorbent, and the amount of added chemical may be controlled not by adjusting the opening of the valve but by other methods, such as by changing the discharge amount of the chemical feed pump. Further, a filtration type or centrifugal type solid-liquid separation device other than a sedimentation type solid-liquid separation tank may be used.

Further, in the above embodiment, the output values of the flow meter, the total flow meter, and the pH meter are input to the calculation section 21, but the output values of the pH meter 26 and the flow meter 18 are A separate pH controller may be provided to adjust the amount of neutralizing agent added based on the pH value.

Furthermore, a PH meter may be installed in the raw water inlet pipe 11 to control the amount of neutralizing agent added by a feedforward method.Of course, a PH meter may be installed in both the raw water inlet pipe 11 and the reaction tank 12 to control the amount of neutralizing agent added in a feedforward method. The amount of neutralizing agent added may be controlled using a combination of the above and the feedback method.

-Also, in order to detect the amount of raw water introduced, the rotation speed of the pump for feeding raw water to the reaction tank can be detected, and the pump discharge amount (raw water feed amount) can be calculated from this rotation speed. good.

[Effects of the Invention] As detailed above, the fluorine-containing wastewater treatment device of the present invention controls the amount of chemicals added in accordance with the raw water load, and the amount of chemicals added is always maintained at an optimal value. Ru. Therefore, (1) There is no need to add excessive chemicals, reducing treatment costs and reducing the amount of sludge generated.

■ Since the reaction in the reaction tank is carried out under optimal conditions, the quality of the treated water is stabilized and fluorine does not exceed the quality standards of the treated water.

((1) Therefore, the reliability of the device is high.

■ Labor saving can be achieved.

Various excellent effects such as these can be achieved.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a conventional device, and FIG. 2 is a system diagram of an embodiment device. 11. Φ Raw water introduction pipe, 12... Reaction tank. 16＠Φ・Solid-liquid separation tank, 18...Flow rate 81°19.2
5...Fu cumulative total, 2011φ-arithmetic controller, 26・φ・pH meter. Agent Patent Attorney Tsuyoshi Shigeno Figure 1 Figure 2

Claims (2)

[Claims] (1) A reaction tank into which fluorine-containing raw water to be treated is introduced, a chemical addition means for adding a chemical for treating fluorine-containing wastewater to the reaction tank, and a reaction liquid received from the reaction tank for solid-liquid separation. a solid-liquid separation means, a flow rate detection means for detecting the flow rate of raw water introduced into the reaction tank, a fluorine cumulative total for detecting the fluorine concentration in the raw water, and a pH of the reaction liquid in the reaction tank.
a PH meter for detecting the flow rate detection means, a calculation unit for calculating the amount of medicine to be added based on the cumulative total of fluorine and the detected value of the PH meter, and a medicine addition means for calculating the amount of addition calculated by the calculation unit. A fluorine-containing wastewater treatment device comprising: a controller for controlling the fluorine-containing wastewater; (2) The fluorine-containing wastewater treatment apparatus according to claim 1, wherein the chemicals are an aluminum salt and a neutralizing agent.