Device for treating high-concentration cyanide-containing wastewater at low cost

Abstract

The utility model discloses a low-cost device for treating high-concentration cyanide-containing wastewater, which comprises a first wastewater delivery pump (1), a primary reaction tank (4), a secondary reaction tank (6), a regulating tank (7) and a second wastewater delivery pump (8) which are sequentially connected, the primary reaction tank (4) is connected with a special cyanide breaking device (2) through a pipeline, and the regulating tank (7) is connected with a NaOH solution storage tank (3) through a pipeline. According to the method disclosed by the utility model, the oxidizing agent is prepared by adopting the special cyanide breaking device, the strong oxidizing property of the oxidizing agent is utilized, the cyanide breaking reaction is carried out on the high-concentration cyanide-containing wastewater treatment device, and the wastewater can stably reach the standard without adjusting the pH value of the wastewater on the basis of not changing the original treatment device.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of sewage treatment, particularly to a device for treating high-concentration cyanide-containing wastewater at low cost. BACKGROUND

[0002] In the national economic construction, cyanide-containing wastewater mainly comes from many industrial productions. Since cyanide-containing wastewater belongs to high-toxicity inorganic wastewater, it has strong toxic effects on organisms and environment, and is wastewater that must be treated compulsorily by the state and cannot be discharged at will or substandardly. Therefore, it has very important practical and social significance to treat cyanide-containing wastewater and discharge it after reaching the standard.

[0003] With the development of economy, the amount of wastewater is increasing, and the amount of cyanide is also increasing. The treatment of cyanide-containing wastewater has been researched by people. At present, the most commonly used and relatively universal method is the hypochlorite oxidation method. This method is relatively mature, stable, and easy to control automatically. However, the effective chlorine content of hypochlorite is low, the effective period is short, it is not easy to store, the dosage is large, the amount of slag is also large, the transportation amount is large, the cyanide breaking capacity is slightly low, the impact resistance is poor, and the treatment cost is also very high. Especially for the treatment of high-concentration cyanide-containing wastewater with a cyanide content of 1000-3000 mg / L, the wastewater treatment has not been stable, and the treatment cost is as high as about 1000 yuan / t, which makes users very headache. Nowadays, the treatment of such high-concentration cyanide-containing wastewater only uses this simple treatment technology, which has been difficult to meet the stable standard and low-cost operation of the wastewater treatment. However, there is no better device and treatment method to replace it at present, so a better treatment technology is always being sought. SUMMARY

[0004] The utility model solves the technical problem to provide a device for treating high-concentration cyanide-containing wastewater at low cost and with simple operation. The device uses a cyanide-breaking special device to prepare an oxidizing agent, utilizes the strong oxidizing property of the oxidizing agent to perform a cyanide-breaking reaction in a high-concentration cyanide-containing wastewater treatment device, and can be performed without changing the original treatment device. Finally, the stable standard of wastewater can be achieved.

[0005] The device for treating high-concentration cyanide-containing wastewater at low cost comprises a first wastewater conveying pump, a first-stage reaction tank, a second-stage reaction tank, a regulating tank, and a second wastewater conveying pump connected in sequence. The first-stage reaction tank is connected with the cyanide-breaking special device through a pipeline. The regulating tank is connected with a NaOH solution storage tank through a pipeline.

[0006] The device, wherein: high concentration cyanide-containing wastewater inlet, oxidant adding port, wastewater overflow port are arranged on the first reaction tank, the high concentration cyanide-containing wastewater inlet is connected with the first wastewater conveying pump through pipeline, the oxidant adding port is connected with the cyanide breaking special device through pipeline, and the wastewater overflow port is communicated with the first reaction tank and the second reaction tank.

[0007] The device, wherein: wastewater inlet, NaOH solution adding port and first wastewater outlet are arranged on the adjusting groove, a second wastewater outlet is arranged on the second reaction tank and connected with the wastewater inlet of the adjusting groove, the NaOH solution adding port is connected with the NaOH solution storage tank through pipeline, and the first wastewater outlet is connected with the second wastewater conveying pump through pipeline.

[0008] The device, wherein: mechanical agitators are arranged in the first reaction tank, the second reaction tank and the adjusting groove.

[0009] The method for treating high concentration cyanide-containing wastewater at low cost is different from prior art in that:

[0010] The device for treating high concentration cyanide-containing wastewater at low cost, and the treatment method using the device can make up the blank of the treatment method for high concentration cyanide-containing wastewater, and change the treatment idea and method of the original oxidation method.

[0011] The utility model discloses a special device for breaking cyanogen is adopted, the thought, method of the oxidation treatment of the cyanogen-containing waste water of conventional use are changed. Before the special device for breaking cyanogen is developed, the high purity generator is changed and is used to break cyanogen, because the oxidizing agent solution is all strong acid, and the quantity is big, and the breaking cyanogen is all required to carry out under the alkaline condition, and the effect is best, therefore, before breaking cyanogen, it is needed to add a large amount of NaOH, and the pH value of neutral waste water is adjusted to alkaline, to ensure that the acidic solution brought by oxidizing agent can be neutralized, in this way, the cyanogen-containing waste water treatment will increase a certain cost, and the processing cost is very high, which is a very headache problem for the user. The special device for breaking cyanogen is adopted, and the acid content of the oxidizing agent solution prepared is less, which is the oxidation agent preparation technology that the domestic does not have at present, therefore, the cyanogen-containing waste water does not need to add NaOH to adjust the pH value, and the oxidizing agent solution can directly break cyanogen in neutral waste water until completely stable and up to standard, which can reduce the comprehensive treatment cost of waste water from the original 1000 yuan / t to < 760 yuan / t, and to < 500 yuan / t, which is a very obvious and remarkable effect, and creates a precedent, which can be achieved only by the special device for breaking cyanogen.

[0012] The utility model discloses a special device for breaking cyanogen is adopted to treat high concentration cyanogen-containing waste water at low cost, which not only reduces manpower and material resources, and has simple process and convenient operation, but also can utilize the original waste water treatment device, effectively saves construction investment, finds a new technical method for enterprises, actively promotes the treatment of high concentration cyanogen-containing waste water at low cost and stable standard, and plays a positive role in the in-depth development of environmental protection.

[0013] The device for treating high concentration cyanogen-containing waste water at low cost will be further described below with reference to the drawings. DRAWINGS

[0014] Figure 1 It is the structure schematic drawing of the device for treating high concentration cyanogen-containing waste water at low cost. CONCRETE IMPLEMENTATION

[0015] As Figure 1 Shown, a kind of device for treating high concentration cyanogen-containing waste water at low cost, including sequentially connected first waste water delivery pump 1, first-stage reaction tank 4, second-stage reaction tank 6, adjusting tank 7 and second waste water delivery pump 8, wherein, first-stage reaction tank 4 is connected with special device for breaking cyanogen 2 by pipeline, and adjusting tank 7 is connected with NaOH solution storage tank 3 by pipeline.

[0016] The high-concentration cyanide-containing wastewater inlet 401, the oxidant adding port 402 and the wastewater overflow port 403 are arranged on the first reaction tank 4; the high-concentration cyanide-containing wastewater inlet 401 is connected with the first wastewater conveying pump 1 through a pipeline; the oxidant adding port 402 is connected with the cyanide-breaking special device 2 through a pipeline; and the wastewater overflow port 403 connects the first reaction tank 4 and the second reaction tank 6;

[0017] The wastewater inlet 701, the NaOH solution adding port 702 and the first wastewater outlet 703 are arranged on the adjusting tank 7; the second wastewater outlet 601 is connected with the wastewater inlet 701; the NaOH solution adding port 702 is connected with the NaOH solution storage tank 3 through a pipeline; and the first wastewater outlet 703 is connected with the second wastewater conveying pump 8 through a pipeline. The mechanical agitator 5 is arranged in the first reaction tank 4, the second reaction tank 6 and the adjusting tank 7.

[0018] The method for treating high-concentration cyanide-containing wastewater at low cost comprises the following steps: using the cyanide-breaking special device to prepare an oxidant on line; in the preparation process, a mixed solution of a cyanide breaker with a concentration of 68-72% sulfuric acid and a concentration of 43-46% is used as raw material, and the volume ratio of the solid solution to the acid is 1:0.50-0.54, wherein the solid solution is the mixed solution of the cyanide breaker; and the reaction conditions in the preparation process of the oxidant are as follows: temperature: 68-73℃, and negative pressure: -6-6.6KPa.

[0019] The cyanide-breaking special device and the cyanide breaker used in the utility model are commercially available products, which are purchased from Shenzhen Zhongke Outech Huahuan Environmental Protection Technology Co., Ltd.

[0020] The method for treating high-concentration cyanide-containing wastewater at low cost comprises the following steps: using the cyanide-breaking special device to prepare an oxidant on line; in the preparation process, a mixed solution of a cyanide breaker with a concentration of 68-72% sulfuric acid and a concentration of 43-46% is used as raw material, and the volume ratio of the solid solution to the acid is 1:0.50-0.54, wherein the solid solution is the mixed solution of the cyanide breaker; and the reaction conditions in the preparation process of the oxidant are as follows: temperature: 68-73℃, and negative pressure: -6-6.6KPa.

[0021] (1) The wastewater containing cyanide with a content of 1060mg / L on the production line is sent into the first reaction tank 4 through the wastewater conveying pump 1, the oxidant is prepared by using the 20000g / h cyanide-breaking special device 2 (the production capacity of the equipment is 20000g / h, that is, 20000g is produced per hour), the cyanide content in the wastewater is analyzed, the operation time of the cyanide-breaking special device 2 is controlled to be 0.55h to quantitatively add the oxidant, NaOH does not need to be added to adjust the pH value of the wastewater, the cyanide-breaking reaction is directly carried out, the stirring is carried out under the agitator 5, and the cyanide-breaking reaction time is 30min.

[0022] (2) The wastewater after the reaction in step (1) is overflowed to the second reaction tank 6, the stirring is carried out under the agitator 5, the cyanide-breaking is continuously carried out, the reaction time is 30min, and the wastewater is completely and stably broken.

[0023] (3) The cyanide-removing reaction-completed wastewater of step (2) is overflowed to the adjusting tank 7, and 5% NaOH solution is added to adjust the pH value of the wastewater under the stirring of the stirrer 5, so that the pH value of the cyanide-removing reaction-completed wastewater is increased from 3.1 to 5.1, and the adding amount of the 5% NaOH solution is controlled, thereby laying a foundation for the subsequent heavy metal treatment.

[0024] (4) The cyanide-removing reaction-completed wastewater of step (3) is sent to the wastewater comprehensive treatment plant by the wastewater delivery pump 8.

[0025] In the utility model, the oxidizing agent is prepared on line and added quantitatively, and the preparation and adding process is carried out together with the wastewater treatment process.

[0026] After the high-concentration cyanide-containing wastewater is treated by the above method, the cyanide content is 0.39 ppm, the cyanide removal standard reaching rate is 100%, and the comprehensive treatment cost is 486 yuan / t.

[0027] Oxidizing agent comparison:

[0028] I. The traditional sodium hypochlorite is used as the oxidizing agent:

[0029] In the method of the utility model, the oxidizing agent is replaced by sodium hypochlorite under the condition that other conditions remain unchanged. Since the content of the sodium hypochlorite solution is low, a large amount of sodium hypochlorite solution needs to be added to the first reaction tank for cyanide-removing reaction for high-concentration cyanide-containing wastewater. In addition, the oxidizing property of sodium hypochlorite is low and unstable, so an excessive amount needs to be added, and the reaction time is increased to about 40 min. Therefore, the wastewater treatment cost is greatly increased to about 1000 yuan / t.

[0030] In addition, the cyanide content of the high-concentration cyanide-containing wastewater fluctuates between 1000-3000 mg / L. Since the sodium hypochlorite has poor impact resistance under the condition of low oxidizing property, the cyanide-removing reaction of the wastewater is very unstable.

[0031] After the high-concentration cyanide-containing wastewater is treated by the above method, the cyanide content is 0.35-0.82 ppm, the cyanide removal standard reaching rate is 96-100%, the treatment effect is very unstable, and the comprehensive treatment cost is 1000-1035 yuan / t.

[0032] The oxidizing agent is prepared by the high-purity generator in the prior art to prepare high-purity chlorine dioxide oxidizing agent, and the difference between the preparation process and the utility model is as follows:

[0033]

[0034] Other unexplained conditions are the same, and the unexplained parameters and methods used in the wastewater treatment process are also the same. When the cyanide-removing device is used, the solid solution here is a cyanide-removing agent mixed solution.

[0035] The cyanide breaker is a product specially used for the cyanide breaking device, and the component of the solid solution of the high-purity generator is different from that of the cyanide breaker, which is the most critical. Only the component is different, the different effects of the utility model can be produced. Meanwhile, the adding amount of the acid of the cyanide breaking device is reduced by more than 60%, the water is also reduced accordingly, the concentration of the solid mixed solution is also improved, the water is reduced by 40%, so the product oxidant is a high-concentration solution, and the negative pressure requirement is higher.

[0036] From the preparation process of the oxidant only, the utility model has the following advantages:

[0037] 1. The preparation cost of the oxidant:

[0038] The adding amount of the acid of the cyanide breaking device is reduced by more than 60%, so the preparation cost of the oxidant is reduced by 32.83%.

[0039] 2. Raw material conversion rate:

[0040] The concentration of the solid mixed solution is improved, and the water is reduced by 40%. After the reaction with the acid, the raw material conversion rate is improved by 3.16%.

[0041] 3. Residual acid amount of waste liquid:

[0042] The residual acid amount of the waste liquid after the reaction is reduced by 66.4%, and the acid-base neutralization cost is greatly saved.

[0043] Comparison of two kinds of oxidants:

[0044] Comparison of the methods and effects of wastewater treatment by using the oxidant prepared by the high-purity generator and the oxidant prepared by the utility model:

[0045] When the oxidant prepared by the high-purity generator is used to treat the wastewater containing cyanide of 1000-3000 mg / L, in addition to the difference in the preparation of the oxidant, the following application differences exist:

[0046] When the oxidant prepared by the high-purity generator is used, 5% NaOH solution needs to be added to the first-stage reaction tank and the second-stage reaction tank respectively, the adding amount is controlled according to the pH value of the wastewater of 5-7, and the reaction time is 30-40 min.

[0047] Through the high-concentration cyanide-containing wastewater treated by the above-mentioned oxidant prepared by the high-purity generator, it is detected and counted that the cyanide content is <0.5 ppm, the cyanide removal rate is 100%, and the comprehensive treatment cost is 690-760 yuan / t.

[0048] When the oxidant of the utility model is used for wastewater treatment, alkali does not need to be added to the reaction tank, and the treatment cost is greatly reduced.

[0049] The above-described embodiments are merely preferred embodiments of the present application, and are not intended to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those of ordinary skill in the art shall fall within the protection scope of the present application as defined by the claims.

Claims

1. A device for low cost treatment of high concentration cyanide containing wastewater, characterized in that: The application relates to a high-concentration cyanide-containing wastewater treatment device which comprises a first wastewater conveying pump (1), a first-stage reaction tank (4), a second-stage reaction tank (6), a regulating tank (7) and a second wastewater conveying pump (8) connected in sequence, wherein the first-stage reaction tank (4) is connected with a cyanide-breaking special device (2) through a pipeline, and the regulating tank (7) is connected with a NaOH solution storage tank (3) through a pipeline.

2. The apparatus of claim 1, wherein: A high-concentration cyanide-containing wastewater inlet (401), an oxidant adding port (402) and a wastewater overflow port (403) are arranged on the first-stage reaction tank (4); the high-concentration cyanide-containing wastewater inlet (401) is connected with the first wastewater conveying pump (1) through a pipeline, the oxidant adding port (402) is connected with the cyanide-breaking special device (2) through a pipeline, and the wastewater overflow port (403) is used for connecting the first-stage reaction tank (4) with the second-stage reaction tank (6).

3. The apparatus of claim 1, wherein: A wastewater inlet (701), a NaOH solution adding port (702) and a first wastewater outlet (703) are arranged on the regulating tank (7); a second wastewater outlet (601) is arranged on the second-stage reaction tank (6) and connected with the wastewater inlet (701); the NaOH solution adding port (702) is connected with the NaOH solution storage tank (3) through a pipeline; and the first wastewater outlet (703) is connected with the second wastewater conveying pump (8) through a pipeline.

4. The apparatus of claim 1, wherein: Mechanical agitators (5) are arranged in the first-stage reaction tank (4), the second-stage reaction tank (6) and the regulating tank (7).

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