Chlorination device for purifying ammonia-nitrogen-containing wastewater

Abstract

The utility model discloses a chlorine adding device for purifying ammonia-nitrogen-containing wastewater, which comprises a PLC (programmable logic controller), a sodium hypochlorite storage tank, a chlorine adding device, a chlorine adding device and a chlorine adding device, the dosing pump is used for pumping sodium hypochlorite in the sodium hypochlorite storage tank into the mixing tank; the water inlet pump is used for pumping ammonia-nitrogen-containing wastewater into the mixing tank; the reaction tank is communicated with the mixing tank and is internally provided with a drainage pump for draining water; according to the utility model, the first OPR on-line monitor is arranged in the mixing tank, the second OPR on-line monitor is arranged in the reaction tank along the water flow direction, and the residual chlorine on-line instrument is arranged at the tail end of the reaction tank, so that on-way ORP and tail end residual chlorine data can be acquired in real time, and the acquired data is transmitted to the PLC; the PLC judges the operation condition of the double-point chlorination process according to a preset program, and dosages are added and reduced in a targeted manner according to the judgment, so that the hysteresis of ammonia-nitrogen wastewater adjustment treatment can be greatly reduced, and the use effect is good.

Description

TECHNICAL FIELD

[0001] The utility model relates to water treatment technical field, concretely is a chlorine adding device for ammonia nitrogen containing wastewater purification. BACKGROUND

[0002] Breakpoint chlorination is one of the technical means for treating low-concentration ammonia-nitrogen-containing wastewater, when the organic matter in water is mainly ammonia-nitrogen compounds, the actual chlorine demand is met, and then the chlorine dosage and residual chlorine content increase. Because the dominant compound in the reaction is different, when the chlorine dosage increases to a certain point, the free chlorine content in the wastewater is the lowest, and the ammonia-nitrogen concentration is reduced to zero; when the chlorine dosage increases beyond the point, the free chlorine in water will increase; therefore, the point is called the breakpoint, and the method of removing ammonia-nitrogen by adding chlorine is called breakpoint chlorination.

[0003] In the current water treatment system for removing ammonia-nitrogen by breakpoint chlorination, the ammonia-nitrogen concentration and residual chlorine concentration are usually monitored at the outlet, and the front-end dosing system is adjusted according to the detection results, which has a large hysteresis in wastewater conditioning and treatment, bringing high difficulty to wastewater conditioning. The ammonia-nitrogen concentration test requires professional personnel to sample and conduct long-term monitoring, which has a certain threshold; the residual chlorine online monitor cannot determine whether the dosing amount is too much or too little according to the residual chlorine data alone because the residual chlorine curve has a break line in the chlorination process, the operation parameters of the whole system are adjusted depending on the experience of professional personnel, and the system parameters cannot be automatically optimized and operated, which needs to be improved. Therefore, we propose a chlorine adding device for ammonia-nitrogen-containing wastewater purification. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a chlorine adding device for ammonia-nitrogen-containing wastewater purification to solve the problems in the background art.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical scheme:

[0006] A chlorine adding device for ammonia-nitrogen-containing wastewater purification, comprising a PLC controller and,

[0007] A sodium hypochlorite storage tank is used to store sodium hypochlorite.

[0008] A dosing pump is used to pump the sodium hypochlorite in the sodium hypochlorite storage tank into a mixing pool.

[0009] A water inlet pump is used to pump ammonia-nitrogen-containing wastewater into the mixing pool.

[0010] A reaction pool is in communication with the mixing pool and is internally provided with a drainage pump for draining water.

[0011] A first OPR online monitor is installed in the mixing pool, a plurality of second OPR online monitors are installed in the reaction pool, and a residual chlorine online monitor is installed in the reaction pool.

[0012] As a further scheme of the utility model: the front end of the reaction pool communicates with the mixing pool, and the drainage pump is installed in the tail end of the reaction pool.

[0013] As a further scheme of the utility model: the second OPR online monitor is sequentially distributed in the reaction pool along the water flow direction, and the residual chlorine online monitor is located at the tail end of the reaction pool.

[0014] As a further scheme of the utility model: the reaction pool is installed with a baffle wall for guiding the water flow.

[0015] As a further scheme of the utility model: the tail end of the reaction pool is installed with a reflux pump, and the reflux pump is used to pump the water in the reaction pool into the mixing pool.

[0016] As a further scheme of the utility model: the mixing pool is installed with a stirrer.

[0017] As a further scheme of the utility model: the volume of the reaction pool is much larger than that of the mixing pool.

[0018] Compared with the prior art, the utility model has the beneficial effects that:

[0019] The utility model can obtain the data of the ORP along the water flow and the residual chlorine at the tail end in real time, and the collected data is transmitted to the PLC controller, the PLC controller judges the operation state of the breakpoint chlorination process according to the preset program, and the amount of the reagent is added or reduced according to the judgment, which can greatly reduce the hysteresis of the ammonia-nitrogen wastewater adjustment treatment, and has good use effect. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a structure schematic view of a chlorine adding device for purifying ammonia-nitrogen-containing wastewater.

[0021] Figure 2 It is an ORP value and chlorine adding amount corresponding relation diagram in the breakpoint chlorination method.

[0022] Figure 3 It is a residual chlorine and chlorine adding amount relation schematic view in the breakpoint chlorination method

[0023] Among them, the PLC controller 1, the first OPR online monitor 2, the residual chlorine online monitor 3, the sodium hypochlorite storage tank 4, the reagent pump 5, the water inlet pump 6, the mixing pool 7, the stirrer 8, the reaction pool 9, the drainage pump 10, the reflux pump 11, the second OPR online monitor 12. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the utility model will be apparently and completely described in connection with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the range protected by the utility model.

[0025] Please refer to Figure 1 In the embodiments of the utility model, a chlorine adding device for purifying ammonia-nitrogen-containing wastewater comprises a PLC controller 1 and

[0026] A sodium hypochlorite storage tank 4 for storing sodium hypochlorite;

[0027] A dosing pump 5 for pumping sodium hypochlorite in the sodium hypochlorite storage tank 4 into a mixing pool 7;

[0028] A water inlet pump 6 for pumping ammonia-nitrogen-containing wastewater into the mixing pool 7, and the hydraulic retention time of water in the mixing pool 7 is about 5-15 min;

[0029] A reaction pool 9 in communication with the mixing pool 7, wherein the volume of the reaction pool 9 is much larger than that of the mixing pool 7, and the reaction pool 9 is internally provided with a drainage pump 10 for draining water;

[0030] The first OPR online monitor 2 is installed in the mixing pool 7, a plurality of second OPR online monitors 12 are installed in the reaction pool 9, and a residual chlorine online monitor 3 is installed in the reaction pool 9.

[0031] The first OPR online monitor 2, the second OPR online monitors 12, the residual chlorine online monitor 3 and the dosing pump 5 are electrically connected with the PLC controller 1.

[0032] During the process of treating ammonia-nitrogen-containing wastewater by the sodium hypochlorite breakpoint chlorination method, the levels of ORP, residual chlorine and the like in water will change according to the different forms of chlorine-containing compounds (monochloroamine, dichloroamine, trichloroamine, free chlorine and the like) in water. After the addition of sodium hypochlorite, the ORP value of water mainly containing monochloroamine in the reaction is about 400 mV, and the ORP value of water mainly containing free chlorine is higher, which can reach more than 600 mV. When the amount of sodium hypochlorite added is insufficient, the chlorine-containing compounds in water only change in form, and the ORP value of the water sample at this stage changes little; when the ammonia-nitrogen in water is gradually consumed, the ORP value of the water sample will be sharply increased and the ORP value will jump if the amount of chlorine added continues to increase. Therefore, the characteristics of the ORP value jump during the breakpoint chlorination process can be combined with the residual chlorine value index to determine whether the amount of chlorine added in water is sufficient. The ORP value and the residual chlorine value of water are controlled to achieve the discharge of ammonia-nitrogen-containing water in the case of appropriate dosing. The ORP values of different ammonia-nitrogen-containing wastewater systems will be slightly different, but the overall change rule is basically the same;

[0033] The utility model discloses a through adopt above -mentioned scheme, combine sodium hypochlorite break point chlorination method's application, through install first OPR on -line monitor 2 in mixed pool 7 and set up second OPR on -line monitor 12 in reaction pool 9 along the water flow direction, and reaction pool 9 end sets up residual chlorine on -line instrument 3, can real -time acquisition along the way ORP and end residual chlorine data, and the data that will gather are transmitted to PLC controller 1, and PLC controller 1 judges break point chlorination process operating condition according to the pre -set program, and according to the judgment pertinence makes the operation of adding and subtracting the amount of drug, can greatly reduce the hysteresis of ammonia nitrogen wastewater regulation and treatment, and the use effect is good.

[0034] Specifically combining Figure 1 In an embodiment of the utility model, the front end of the reaction pool 9 communicates with the mixed pool 7, and the drainage pump 10 is installed in the end of the reaction pool 9 to make the water in the reaction pool 9 flow from the front end to the end by the drainage pump 10.

[0035] Specifically combining Figure 1 In an embodiment of the utility model, the second OPR on -line monitors 12 are sequentially distributed along the water flow direction in the reaction pool 9, and the residual chlorine on -line monitor 3 is located in the reaction pool 9 close to the end of the reaction pool 9 to ensure the reliability of water quality detection in different reaction stages.

[0036] In addition, in an embodiment of the utility model, the reaction pool 9 is installed with a baffle wall for guiding the water to avoid the short flow of the water in the reaction pool 9.

[0037] Specifically combining Figure 1 In an embodiment of the utility model, the backflow pump 11 is installed close to the end in the reaction pool 9, and the backflow pump 11 is used to pump the water in the reaction pool 9 into the mixed pool 7, and by the setting of the backflow pump 11, the backflow ratio parameter is controlled by the PLC controller 1 according to the water quality change, and the backflow water reenters the mixed pool 7 to mix with the raw water, thereby reducing the system fluctuation.

[0038] Specifically combining Figure 1 In an embodiment of the utility model, the mixed pool 7 is installed with the stirrer 8 to stir the water in the mixed pool 7, so that the ammonia nitrogen containing wastewater and sodium hypochlorite are mixed more uniformly.

[0039] The specific use method of the utility model is as follows:

[0040] In the system starting stage, the flow and start-stop of the dosing pump 5 are manually controlled, the ammonia nitrogen in the effluent is controlled to reach the standard, and during this period, the suitable parameter setting is determined for subsequent normal operation, and the specific parameter determination steps are as follows:

[0041] 1) PLC controller 1 records the data of the gradual increase of ORP at each point along the way and the gradual change of residual chlorine at the end with the increasing amount of sodium hypochlorite dosing during the system start-up phase, and selects and sets the corresponding break point chlorine addition curve B point and C point time (such as shown) according to the residual chlorine data; Figure 3

[0042] 2) According to the ORP values at each point along the way at B point and C point time, the data collected from the first OPR online monitor 2 and the three second OPR online monitors 12 are respectively assigned weights of 0.1, 0.2, 0.3, and 0.4, and the corresponding ORP weighted average value at this time is calculated to represent the ORP value level of the wastewater in the whole system, thereby reducing the influence of uneven water quality in the pool on subsequent dosing adjustment;

[0043] 3) Take the middle value (such as 450 mV) of the ORP weighted average value at each point along the way at B point and C point time as the ORP minimum control value (confirmed or corrected by manual input);

[0044] 4) Take the residual chlorine value at the end at C point time as the minimum value of the residual chlorine target control value (confirmed or corrected by manual input), and set the residual chlorine discharge limit (such as 0.5 mg / L) as the maximum value of the residual chlorine target control value (confirmed or corrected by manual input).

[0045] During the formal operation phase, the real-time data of all online monitors and the residual chlorine online monitor 3 are collected every minute, and the sodium hypochlorite dosing amount is adjusted in real time according to the change trend of the real-time recorded ORP value, residual chlorine value, and the adjustment record of sodium hypochlorite dosing amount:

[0046] 1) If the ammonia nitrogen concentration of the influent becomes high, the ORP weighted average value (such as 420 mV) is lower than the ORP minimum control value (such as 450 mV) determined during the debugging phase, and the sodium hypochlorite dosing amount is increased to the set maximum value until the ORP weighted average value along the way is higher than the ORP minimum control value (such as 450 mV) determined during the debugging phase after a certain time interval;

[0047] 2) When the ORP weighted average value along the way exceeds the ORP minimum control value (such as 450 mV) determined during the debugging phase, adjust the sodium hypochlorite dosing amount based on ORP and residual chlorine:

[0048] 2-1) If the end residual chlorine value increases compared to the value collected in the previous minute, and the ORP weighted average value also increases at the 5th minute, then decrease the sodium hypochlorite dosing amount by the set dosing adjustment amplitude ΔD (such as 1% of the maximum dosing amount).

[0049] ​2-2) If the end residual chlorine value collected at the 10th minute is higher than that collected at the previous minute, and the ORP weighted average value is lower, then the sodium hypochlorite dosage is increased by the set dosage adjustment range ΔD (e.g. 1% of the maximum dosage).

[0050] 2-3) If the end residual chlorine value collected at the 15th minute is lower than that collected at the previous minute, and the ORP weighted average value is lower, then the sodium hypochlorite dosage is decreased by the set dosage adjustment range ΔD (e.g. 1% of the maximum dosage).

[0051] 2-4) If the end residual chlorine value collected at the 20th minute is lower than that collected at the previous minute, and the ORP weighted average value is higher, then the sodium hypochlorite dosage is increased by the set dosage adjustment range ΔD (e.g. 1% of the maximum dosage).

[0052] 2-5) If the end residual chlorine value remains unchanged (the increase / decrease range is lower than the set value) compared with the previous minute, then the sodium hypochlorite dosage is increased by the set dosage adjustment range ΔD (e.g. 1% of the maximum dosage).

[0053] 2-6) The set dosage adjustment range can be floating within a set range according to a set procedure: if the sodium hypochlorite dosage is increased or decreased in the previous 5 consecutive sampling time intervals, and the sodium hypochlorite dosage still needs to be increased or decreased at the current time, then the sodium hypochlorite dosage adjustment range is increased by 1 level (e.g. the dosage change range is changed from 1% of the maximum dosage to 2% of the maximum dosage); if the increase / decrease adjustment direction of the sodium hypochlorite dosage at the current time is opposite to the adjustment direction of the sodium hypochlorite dosage at the last 5 sampling times, then the sodium hypochlorite dosage adjustment range is decreased by 1 level (e.g. the dosage change range is changed from 1% of the maximum dosage to 0.5% of the maximum dosage).

[0054] In addition, the PLC controller 1 collects all the 4 ORP monitor data, and calculates the variance of all the ORP data at the current time, and the greater the variance, the more uneven the water quality at the inlet and outlet. The calculated variance result is compared with a plurality of gradient threshold values set, to determine different reflux ratio gradients. If the variance is high, the reflux pump 11 is controlled to increase the reflux ratio (e.g. the reflux ratio is 300%), to improve the system stability; if the variance is low, the reflux pump 11 is controlled to decrease the reflux ratio (e.g. the reflux ratio is 0-50%), to reduce the energy consumption.

[0055] Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A chlorination device for purifying ammonia nitrogen-containing wastewater, characterized in that: The PLC controller (1) and A sodium hypochlorite storage tank (4) for storing sodium hypochlorite; A dosing pump (5) for pumping sodium hypochlorite in the sodium hypochlorite storage tank (4) into a mixing tank (7); A water inlet pump (6) for pumping ammonia-nitrogen-containing wastewater into the mixing tank (7); A reaction tank (9) in communication with the mixing tank (7) and internally provided with a drainage pump (10) for draining water; The mixing tank (7) is provided with a first OPR online monitor (2), the reaction tank (9) is provided with a plurality of second OPR online monitors (12), and the reaction tank (9) is provided with a residual chlorine online monitor (3).

2. The chlorine feeding device for purifying ammonia-nitrogen-containing wastewater according to claim 1, characterized by: The front end of the reaction tank (9) is in communication with the mixing tank (7), and the drainage pump (10) is installed in the end of the reaction tank (9).

3. The chlorine feeding device for purifying wastewater containing ammonia nitrogen according to claim 1, characterized in that: The plurality of second OPR online monitors (12) are sequentially distributed in the reaction tank (9) along the water flow direction, and the residual chlorine online monitor (3) is located near the end of the reaction tank (9) in the reaction tank (9).

4. The chlorine feeding device for purifying wastewater containing ammonia nitrogen according to claim 1, characterized in that: The reaction tank (9) is provided with a baffle wall for guiding water flow.

5. The chlorine feeding device for purifying wastewater containing ammonia nitrogen according to claim 1, characterized in that: The end of the reaction tank (9) is provided with a reflux pump (11) for pumping water in the reaction tank (9) into the mixing tank (7).

6. The chlorine feeding device for purifying wastewater containing ammonia nitrogen according to claim 1, characterized in that: The mixing tank (7) is provided with a stirrer (8).

7. The chlorine feeding device for purifying wastewater containing ammonia nitrogen according to claim 1, characterized in that: The volume of the reaction tank (9) is much larger than that of the mixing tank (7).

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