阅读说明：本技术 发电厂中和池废水cod处理系统及其处理方法 (COD treatment system and treatment method for wastewater of neutralization pond of power plant ) 是由 许怀鹏 张永福 杜伟华 周黄斌 孔苑 杜娟 于 2019-10-21 设计创作，主要内容包括：本发明公开了一种发电厂中和池废水COD处理系统,中和池(1)设置控制器(7)、中和泵(2)；处理系统设置循环管道(11),中和泵(2)设置在循环管道(11)的起始端,然后依次在循环管道(11)上设置废水排放阀(3)、废水循环阀(4)、PH计(5)、ORP测定仪(6)、加药喷射器(10)；在循环管道(11)的末端设置喷嘴(12)。本发明还公开了该处理系统的处理方法。采用上述技术方案,实现废水CODGr自动调节处理,可以迅速降低中和池废水CODGr值,满足达标排放的要求；且系统结构简单,既实施方法方便快捷,又便于设备维护。(The invention discloses a COD treatment system for wastewater in a neutralization pond of a power plant, wherein a controller (7) and a neutralization pump (2) are arranged in the neutralization pond (1); the treatment system is provided with a circulating pipeline (11), a neutralizing pump (2) is arranged at the starting end of the circulating pipeline (11), and then a wastewater discharge valve (3), a wastewater circulating valve (4), a PH meter (5), an ORP measuring instrument (6) and a dosing ejector (10) are sequentially arranged on the circulating pipeline (11); a nozzle (12) is provided at the end of the circulation duct (11). The invention also discloses a processing method of the processing system. By adopting the technical scheme, the CODCr of the wastewater is automatically adjusted, the CODCr value of the wastewater in the neutralization pond can be rapidly reduced, and the requirement of up-to-standard discharge is met; and the system has simple structure, and the implementation method is convenient and quick and is convenient for equipment maintenance.)

1. The COD treatment system of power plant neutralization pond waste water, neutralization pond (1) set up controller (7), neutralization pump (2), its characterized in that: the treatment system is provided with a circulating pipeline (11), the neutralization pump (2) is arranged at the starting end of the circulating pipeline (11), and then a wastewater discharge valve (3), a wastewater circulating valve (4), a PH meter (5), an ORP (oxidation-reduction potential) tester (6) and a dosing ejector (10) are sequentially arranged on the circulating pipeline (11); a nozzle (12) is provided at the end of the circulation duct (11).

2. The COD treatment system for wastewater in a power plant neutralization pond according to claim 1, characterized in that: the drug adding ejector (10) is connected with the drug adding valve (8) through a pipeline; the dosing valve (8) is connected with the oxidant dissolving box (9) through a pipeline.

3. The COD treatment system for wastewater in a power plant neutralization pond according to claim 2, characterized in that: the medicine adding valve (8) is connected with the controller (7) through a control signal line.

4. The COD treatment system for wastewater in a power plant neutralization pond according to claim 1, characterized in that: the waste water discharge valve (3), the waste water circulating valve (4), the PH meter (5), the ORP measuring instrument (6) and the dosing ejector (10) are all connected with the controller (7) through control signal lines.

5. The COD treatment system for wastewater in a power plant neutralization pond according to claim 1, characterized in that: the water inlet of the neutralization pump (2) is arranged in a downward dent at the bottom of the neutralization tank (1).

6. The COD treatment system for wastewater in a power plant neutralization pond according to claim 1, characterized in that: the number of the nozzles (12) is more than one, the circulating pipeline (11) is horizontally arranged at the bottom of the neutralizing tank (1), and the nozzles (12) are distributed on the horizontally arranged circulating pipeline (11) at intervals.

7. The treatment method of the COD treatment system of the wastewater of the neutralization pond in the power plant according to any one of claims 1 to 6, characterized in that: the processing method comprises the following steps:

step 1, closing a wastewater discharge valve (3), opening a wastewater circulating valve (4), and establishing wastewater circulation in a neutralization pond (1) through a neutralization pump (2) or a wastewater circulating pump before wastewater in the neutralization pond (1) is discharged;

step 2, a PH meter (5) detects the PH value of the wastewater;

step 3, adjusting the pH value of the wastewater by adding an acidic or alkaline medium;

step 4, when the PH value of the wastewater reaches 8.0-8.5, the ORP measuring instrument (6) starts to detect the ORP value of the wastewater, and the controller (7) automatically adjusts the opening of the dosing valve (8) according to the ORP value of the wastewater;

step 5, quantitatively and uniformly adding the oxidant solution in the dissolving tank (9) into the wastewater through an ejector (10);

and 6, after the ORP value of the wastewater is reduced to a specified value, namely the CODCr of the wastewater reaches the standard, closing the wastewater circulating valve (3), opening the wastewater discharge valve (3), and discharging the wastewater.

8. The treatment method of the COD treatment system for wastewater in a power plant neutralization pond according to claim 7, characterized in that: before the treatment process, an oxidant solution is prepared in an oxidant solution tank (9), wherein the oxidant comprises NaClO and bleaching powder; the effective concentration of the oxidant is controlled to be 10-20%.

9. The treatment method of the COD treatment system for wastewater in a power plant neutralization pond according to claim 7, characterized in that: in the step 1, the circulation flow is controlled to be 1/3-1/4 and the volume/hour of the neutralization tank (1).

10. The treatment method of the COD treatment system for wastewater in a power plant neutralization pond according to claim 7, characterized in that: in the step 6, the predetermined value of ORP is 800 to 1000 mV.

Technical Field

The invention belongs to the technical field of power generation wastewater treatment, and particularly relates to a thermal power plant neutralization pond wastewater COD treatment system and an automatic adjustment treatment method thereof.

Background

Chemical Oxygen Demand (COD) is the amount of oxidant consumed in treating a water sample with a strong oxidant under certain conditions. The reducing substances in the water are mainly organic substances. Therefore, Chemical Oxygen Demand (COD) is often used as an index to measure the content of organic substances in water. The larger the chemical oxygen demand, the more serious the water body is polluted by organic matters. The COD of the sewage is detected by a potassium dichromate method.

A large amount of waste water is produced during operation, regeneration and chemical cleaning of a boiler feedwater system of a thermal power plant, pollution factors in the waste water mainly comprise suspended matters, PH values, CODCr and the like, and a neutralization pond is usually arranged for storing and treating the waste water. Along with the increase of environmental protection, the discharge index of the waste water is more and more strict, and GB13456-2012 discharge Standard of Water pollutants for iron and Steel industry requires that the CODCr of the discharged water of the thermal power plant is not more than 50 mg/L. The CODCr waste water of the neutralization pond is difficult to reach the discharge standard.

The method for reducing the CODCr of the wastewater in the neutralization pond at present adopts aeration, utilizes O2 in the air to oxidize and degrade reducing substances in the wastewater to achieve the aim of reducing the CODCr in water, and takes the detection that the CODCr value in the water is smaller than a standard value as a control terminal. Because the oxidation capacity of air is weak, the CODCr in water is slowly degraded, the time is too long, and even the normal operation of a boiler water supply system is influenced. The method for determining the COD value in water by adopting a potassium dichromate method has the advantages of complex operation, time consumption of about 2.5 hours for single time, inconvenience for field control, and secondary pollution caused by the fact that the used analytical reagent relates to a highly toxic medicine, and incapability of realizing automatic COD regulation treatment.

Disclosure of Invention

The invention provides a COD treatment system for wastewater in a neutralization pond of a power plant, and aims to realize automatic adjustment treatment of CODCr of the wastewater.

In order to achieve the purpose, the invention adopts the technical scheme that:

the COD treatment system for the wastewater of the neutralization pond of the power plant is characterized in that the neutralization pond is provided with a controller and a neutralization pump; the treatment system is provided with a circulating pipeline, the neutralization pump is arranged at the starting end of the circulating pipeline, and then a wastewater discharge valve, a wastewater circulating valve, a PH meter, an ORP (oxidation-reduction potential) tester and a dosing ejector are sequentially arranged on the circulating pipeline; a nozzle is provided at the end of the circulation pipe.

The drug adding ejector is connected with the drug adding valve through a pipeline; the dosing valve is connected with the oxidant dissolving box through a pipeline.

The medicine adding valve is connected with the controller through a control signal line.

The wastewater discharge valve, the wastewater circulating valve, the PH meter, the ORP measuring instrument and the dosing ejector are all connected with the controller through control signal lines.

The water inlet of the neutralization pump is arranged in a downward dent at the bottom of the neutralization tank.

The number of the nozzles is more than one, the circulating pipeline is horizontally arranged at the bottom of the neutralizing tank, and the nozzles are distributed on the horizontally arranged circulating pipeline at intervals.

In order to realize the same purpose as the technical scheme, the invention also provides a treatment method adopted by the power plant neutralization pond wastewater COD treatment system, which comprises the following steps:

step 1, closing a wastewater discharge valve, opening a wastewater circulating valve, and establishing wastewater circulation in a neutralization tank through a neutralization pump or a wastewater circulating pump before wastewater in the neutralization tank is discharged;

step 2, detecting the pH value of the wastewater by a pH meter;

step 3, adjusting the pH value of the wastewater by adding an acidic or alkaline medium;

step 4, when the PH value of the wastewater reaches 8.0-8.5, an ORP measuring instrument starts to detect the ORP value of the wastewater, and a controller automatically adjusts the opening of a dosing valve according to the ORP value of the wastewater;

step 5, quantitatively and uniformly adding the oxidant solution in the dissolving tank into the wastewater through an ejector;

and 6, after the ORP value of the wastewater is reduced to a specified value, namely the CODCr of the wastewater reaches the standard, closing the wastewater circulating valve, opening the wastewater discharge valve and discharging the wastewater.

Before the treatment process, an oxidant solution is prepared in an oxidant dissolving tank, wherein the oxidant comprises NaClO and bleaching powder; the effective concentration of the oxidant is controlled to be 10-20%.

In the step 1, the circulation flow is controlled to be 1/3-1/4 neutralization pond volume/hour.

In the step 6, the predetermined value of ORP is 800 to 1000 mV.

By adopting the technical scheme, the CODCr of the wastewater is automatically adjusted, the CODCr value of the wastewater in the neutralization pond can be rapidly reduced, and the requirement of standard discharge is met; and the system has simple structure, and the implementation method is convenient and quick and is convenient for equipment maintenance.

Drawings

The contents of the drawings and the references therein are briefly described as follows:

FIG. 1 is a view showing the structure of a COD treatment system for wastewater from a neutralization pond according to the present invention.

Labeled as:

1. the device comprises a neutralization pond, 2, a neutralization pump, 3, a wastewater discharge valve, 4, a wastewater circulating valve, 5, a PH meter, 6, an ORP measuring instrument, 7, a controller, 8, a dosing valve, 9, an oxidant dissolving box, 10, a dosing ejector, 11, a circulating pipeline, 12 and a nozzle.

Detailed Description

The following detailed description of the embodiments of the present invention will be given in order to provide those skilled in the art with a more complete, accurate and thorough understanding of the inventive concept and technical solutions of the present invention.

The structure of the invention as shown in figure 1 is a waste water COD treatment system of a neutralization pond of a power plant, and the neutralization pond 1 is provided with a controller 7 and a neutralization pump 2.

In order to overcome the problems in the prior art and achieve the invention purpose of automatic adjustment treatment of waste water CODCr, the invention adopts the technical scheme that:

as shown in figure 1, the COD treatment system for the wastewater in the neutralization pond of the power plant is provided with a circulating pipeline 11, a neutralization pump 2 is arranged at the starting end of the circulating pipeline 11, and then a wastewater discharge valve 3, a wastewater circulating valve 4, a PH meter 5, an ORP measuring instrument 6 and a dosing ejector 10 are sequentially arranged on the circulating pipeline 11; a nozzle 12 is provided at the end of the circulation duct 11.

The invention adopts the method that the oxidant is added into the neutralization tank, and the oxidation-reduction potential (ORP) value of the wastewater detected in real time reaches the standard as the control terminal, so that the automatic control of the adjustment treatment of the CODCr value of the wastewater is realized, the CODCr value of the wastewater in the neutralization tank can be rapidly reduced, and the qualified discharge is met; the device is convenient and quick, and is convenient for equipment maintenance. The automatic adjustment treatment method can effectively reduce the CODCr value of the wastewater, ensure the wastewater to reach the standard and be discharged, and has simple system and convenient installation and maintenance.

The ORP value (oxidation-reduction potential of water) is an important indicator of water quality and can characterize the relative magnitude of its oxidation or reduction. Although the water quality can not be independently reflected, other water quality indexes can be integrated to reflect the ecological environment in the aquarium system. The higher the ORP value is, the stronger the oxidation property and the weaker the reduction property of water are, and the lower the ORP value is, the weaker the oxidation property and the stronger the reduction property are.

The drug adding ejector 10 is connected with the drug adding valve 8 through a pipeline; the dosing valve 8 is connected with an oxidant dissolving tank 9 through a pipeline.

The most direct and effective method for removing the organic matters in the wastewater is to add a reinforced oxidant into the wastewater, and the oxidant can quickly oxidize and decompose the organic matters in the wastewater so as to reduce the CODCr value of the wastewater.

The medicine adding valve 8 is connected with the controller 7 through a control signal line.

The wastewater discharge valve 3, the wastewater circulating valve 4, the PH meter 5, the ORP measuring instrument 6 and the dosing ejector 10 are all connected with the controller 7 through control signal lines.

The controller 7 receives the signals sent by the detection sensors, makes judgment, sends control signals to each actuating mechanism and carries out the treatment of the wastewater.

The water inlet of the neutralization pump 2 is arranged in a downward concave of the bottom of the neutralization tank 1.

The arrangement of the recess enables the flow of the waste water to be more sufficient; the position of the recess is staggered with that of the nozzle 12, so that the wastewater is circulated more fully.

The number of the nozzles 12 is more than one, the circulating pipeline 11 is horizontally arranged at the bottom of the neutralization tank 1, and the nozzles 12 are distributed on the horizontally arranged circulating pipeline 11 at intervals.

The arrangement of the plurality of nozzles 12 enables the circulated wastewater to be distributed and dispersed, chemical substances are uniformly distributed as much as possible, and the properties of the wastewater are truly and comprehensively reflected.

The ORP composite electrode and the mV meter can form a measuring system to quickly measure the oxidation-reduction potential of water. The source of the waste water of the neutralization pond in the power plant is relatively stable, the composition of the reducing substances is relatively fixed, and when strong oxidant is added, the change of the ORP of the waste water and the degradation and oxidation degree of COD have good correlation in the reaction process.

Experiments show that when the PH value of the waste water in the neutralization pond of the power plant is 8.0-8.5 (the discharge standard is 6.0-9.0), the ORP value of the waste water is controlled to be 750-850 mV, the content of residual chlorine in the water can reach 2.5-3.0 mg/l, and the CODCr of the waste water is less than 50mg/l, so that the waste water can be discharged up to the standard. The ORP value of the wastewater is adopted to indirectly reflect the size of CODCr in the wastewater, and the addition of the oxidant is controlled according to the ORP value of the wastewater obtained by rapid measurement, so that the CODCr of the wastewater can be automatically adjusted and treated completely.

In order to realize the same purpose as the technical scheme, the invention also provides a treatment method adopted by the power plant neutralization pond wastewater COD treatment system, which comprises the following steps:

step 1, closing a wastewater discharge valve 3, opening a wastewater circulating valve 4, and establishing wastewater circulation inside a neutralization pond 1 through a neutralization pump 2 or a wastewater circulating pump before wastewater in the neutralization pond 1 is discharged;

step 2, a PH meter 5 detects the PH value of the wastewater;

step 3, adjusting the pH value of the wastewater by adding an acidic or alkaline medium;

step 4, when the PH value of the wastewater reaches 8.0-8.5, the ORP measuring instrument 6 starts to detect the ORP value of the wastewater, and the controller 7 automatically adjusts the opening of the dosing valve 8 according to the ORP value of the wastewater;

step 5, quantitatively and uniformly adding the oxidant solution in the dissolving tank 9 into the wastewater through an ejector 10;

and 6, after the ORP value of the wastewater is reduced to a specified value, namely the CODCr of the wastewater reaches the standard, closing the wastewater circulating valve 3, opening the wastewater discharge valve 3 and discharging the wastewater.

Before the treatment process, an oxidant solution is prepared in an oxidant solution tank 9, wherein the oxidant comprises NaClO and bleaching powder; the effective concentration of the oxidant is controlled to be 10-20%.

In the step 1, the circulation flow is controlled to be 1/3-1/4 and the volume/hour of a neutralization pond 1.

In the step 6, the predetermined value of ORP is 800 to 1000 mV.

The invention has been described above with reference to the accompanying drawings, it is obvious that the invention is not limited to the specific implementation in the above-described manner, and it is within the scope of the invention to apply the inventive concept and solution to other applications without substantial modification.