Energy-saving universal high-salt wastewater treatment system and application method thereof

Abstract

The present invention discloses an energy-saving universal high-salinity wastewater treatment system and an application method thereof, comprising a raw water buffer unit, a coagulation unit, an advanced oxidation unit, an adsorption and hardness removal unit, a wastewater collection unit and a three-effect evaporation supporting device, wherein the coagulation unit is used to remove most of the suspended solids and a small amount of COD, the advanced oxidation unit is used to remove most of the COD, the adsorption and hardness removal unit is used to remove calcium and magnesium ions, and the three-effect evaporation supporting device is used to concentrate and reduce the wastewater, and the concentrated mixed salt can be purified, recovered or incinerated according to its utilization value. The present invention has the advantages of a wide range of applicable water quality, high treatment efficiency, low energy consumption, low cost, etc., and is of great significance for enhancing my country's water resource utilization capacity and ensuring water resource security.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial wastewater, and in particular to an energy-saving universal high-salt wastewater treatment system and an application method thereof. Background Art

[0002] High-salt wastewater has the characteristics of high salt content, high COD and low calorific value. At present, multi-effect evaporation, MVR and other technologies are often used to treat high-salt wastewater. However, since high-salt wastewater contains a large amount of organic matter and calcium and magnesium ions, it is easy to cause scaling and blockage of equipment in actual treatment, which greatly reduces the treatment efficiency, increases the difficulty of treatment and increases the cost.

[0003] The multi-process coupling method can not only achieve the effective removal of multiple targets, but also greatly reduce the treatment cost. However, most of the current coupling processes are only for wastewater with certain characteristics, and the treatment effect is not significant for high-salinity wastewater with complex water quality and large fluctuations. Therefore, developing a high-salinity wastewater treatment system with strong universality and high treatment efficiency to achieve clean and efficient treatment of high-salinity wastewater is of great significance to promoting water conservation in my country and ensuring water safety. Summary of the invention

[0004] An energy-saving universal high-salt wastewater treatment system and its application method, which use high-temperature industrial waste gas as the heat source and through multi-system coupling and linkage, solves the problems existing in traditional high-salt wastewater treatment technology, such as single applicable water quality, easy scaling and clogging of equipment, low efficiency, high energy consumption, and high cost. It is of great significance to enhance my country's water resource utilization capacity and ensure water resource security.

[0005] In order to achieve the purpose of the present invention, an energy-saving universal high-salinity wastewater treatment system and its application method are provided, which include a storage tank, a flocculation tank, an advanced oxidation tank, an adsorption tower, a resin ion exchange column, a collection tank and a triple-effect evaporation supporting device. The inlet end pipeline of the storage tank is connected to the high-salinity wastewater raw water, and the outlet end pipeline is connected to the flocculation tank; the inlet end pipeline of the flocculation tank is connected to the flocculant, and the outlet end pipeline is connected to the advanced oxidation tank; the inlet end pipeline of the advanced oxidation tank is connected to the oxidant, the outlet end pipeline of the advanced oxidation tank is connected to the adsorption tower, and the outlet end pipeline of the resin ion exchange column is connected to the adsorption tower. The pipeline is connected to the collection tank. The three-effect evaporation supporting device is composed of a three-effect multi-stage evaporator, a tail gas condenser, and a water storage tank. The outlet pipeline of the collection tank is connected to the three-effect multi-stage evaporator. The discharge pipelines of the storage tank, flocculation tank, and advanced oxidation tank are connected to the sludge concentration tank. A stirrer is provided inside the flocculation tank and the advanced oxidation tank. The inlet and outlet pipelines of the storage tank, flocculation tank, and advanced oxidation tank are all provided with electric valves and flow meters. The wastewater flow and the amount of reagent added are controlled by the linkage of the electric valve and the flow meter to achieve accurate matching of the reagent and the wastewater index. In the above technical scheme, the flocculation tank is used to remove most of the suspended and a small amount of COD; the advanced oxidation tank is used to remove most of the COD; the adsorption tower and the resin ion exchange column are used to remove calcium and magnesium ions.

[0006] As a further improvement of the above scheme, the flocculant added to the flocculation tank is an organic-inorganic composite flocculant, the organic flocculant includes polyacrylamide and starch-based flocculant, and the inorganic flocculant includes polyaluminum chloride, polyaluminum chloride iron, and polyaluminum silicate iron. The specific addition combination and proportion can be determined according to the different suspended matter in the wastewater.

[0007] As a further improvement of the above scheme, a lime-sodium carbonate solution is added to the adsorption tower to enhance the adsorption effect on calcium and magnesium ions.

[0008] As a further improvement of the above scheme, the resin ion exchange column uses a super-crosslinked chloromethylated resin modified with thiopropionamide, and the adsorption removal rates of calcium and magnesium ions can reach 400-420 mg / g and 330-350 mg / g respectively, which can provide more adsorption sites for the adsorbate.

[0009] As a further improvement of the above solution, the flow meter on the inlet end pipeline connecting the flocculation tank and the flocculant is a solid flow meter.

[0010] As a further improvement of the above scheme, the oxidant is one or more of H2O2 and FeSO4. The combination and proportion can be adjusted according to the different COD contents in the wastewater.

[0011] As a further improvement of the above solution, centrifugal pumps are provided on the outlet pipelines of the storage tank, flocculation tank, advanced oxidation tank and collection tank.

[0012] As a further improvement of the above solution, electric valves are provided on the pipelines connecting the adsorption tower, the resin ion exchange column and the collection tank, as well as on the pipeline at the outlet end of the collection tank.

[0013] As a further improvement of the above scheme, the evaporation heat source of the three-effect evaporation supporting device is industrial high-temperature exhaust gas, which does not require additional energy consumption and achieves energy-saving treatment of high-salt wastewater.

[0014] An application method of an energy-saving universal high-salinity wastewater treatment system comprises the following steps:

[0015] S1. Store the high-salinity wastewater in a storage tank, start the centrifugal pump to pump the wastewater into the flocculation tank, start the agitator, and add flocculant into the flocculation tank;

[0016] S2. Start the centrifugal pump to send the supernatant in the flocculation tank to the advanced oxidation tank, start the agitator, and add the oxidant to the advanced oxidation tank;

[0017] S3. Start the centrifugal pump to send the supernatant in the advanced oxidation tank into the adsorption tower, the reacted liquid enters the resin exchange column, and the reacted liquid in the resin exchange column enters the collection tank;

[0018] S4. Start the centrifugal pump to send the liquid in the collection tank to the three-effect evaporation supporting device for evaporation and concentration;

[0019] S5. The mixed salt concentrated in step S4 is further separated, purified or incinerated according to its practical value, and the condensed water generated during the evaporation process is reused as industrial water;

[0020] S6. After the reaction is completed, open the outlets of the storage tank, flocculation tank, and advanced oxidation tank to discharge the sludge into the sludge thickening tank.

[0021] The beneficial effects of the present invention are:

[0022] Compared with the prior art, the present invention provides an energy-saving universal high-salt wastewater treatment system and its application method, which places the raw water of high-salt wastewater in a storage tank, pumps the wastewater into a flocculation tank through a centrifugal pump, adds flocculant into the flocculation tank, starts the agitator to stir at a uniform speed; starts the centrifugal pump to send the supernatant into the advanced oxidation tank, adds oxidant into the advanced oxidation tank, starts the agitator to stir at a uniform speed; starts the centrifugal pump to send the supernatant into the adsorption tower, and the reacted liquid flows into the resin exchange column; the reacted liquid in the resin exchange column enters the collection tank, and enters the three-effect evaporation supporting device for evaporation and concentration under the action of the centrifugal pump. The concentrated mixed salt is further separated, purified or incinerated according to its practical value, and the condensed water generated during the evaporation process can be reused for industrial water. After the reaction, the discharge pipelines of the storage tank, flocculation tank and advanced oxidation tank are opened to discharge the sludge into the sludge concentration tank.

[0023] Compared with the prior art, the present invention produces the following beneficial effects:

[0024] (1) The present invention can flexibly adjust the type and proportion of reagent addition according to different water qualities, and is generally applicable to high-salt wastewater;

[0025] (2) The present invention realizes efficient removal of calcium and magnesium ions by combining an adsorption tower and a resin exchange column, which can effectively reduce the risk of scaling and clogging in subsequent evaporation, extend the service life of the equipment, and improve the processing efficiency;

[0026] (3) The present invention utilizes industrial high-temperature waste gas as a heat source, and the produced water can be reused for industrial water use, which has the characteristics of energy saving and consumption reduction, and truly realizes "treating waste with waste and turning waste into treasure". BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings, wherein:

[0028] Figure 1 It is a schematic diagram of the structure of the present invention. DETAILED DESCRIPTION

[0029] like Figure 1As shown, a raw water buffer unit, a coagulation unit, an advanced oxidation unit, an adsorption and hardness removal unit, a wastewater collection unit and a three-effect evaporation supporting device 7, wherein the raw water buffer unit is composed of a storage tank 1, the inlet end pipeline of the storage tank 1 is connected to the high-salt wastewater raw water, and the outlet end pipeline is connected to the flocculation tank 2 of the coagulation unit; the inlet end pipeline of the flocculation tank 2 is connected to the flocculant, and the outlet end pipeline is connected to the advanced oxidation tank 3 of the advanced oxidation unit, and the inlet end pipeline of the advanced oxidation tank 3 is connected to the oxidant, the adsorption and hardness removal unit includes an adsorption tower 4 and a resin ion exchange column 5, the outlet end pipeline of the advanced oxidation tank 3 is connected to the adsorption tower 4, the outlet end pipeline of the resin ion exchange column 5 is connected to the collection tank 6 of the wastewater collection unit, the three-effect evaporation supporting device 7 is composed of a three-effect multi-stage evaporator, a tail gas condenser 8, and a produced water storage tank 9, the outlet end pipeline of the collection tank 6 is connected to the three-effect multi-stage evaporator, the storage tank 1, the flocculation tank 2 ... The discharge pipelines of the coagulation tank 2 and the advanced oxidation tank 3 are commonly connected to the sludge thickening tank 10. A stirrer 11 is arranged inside the flocculation tank 2 and the advanced oxidation tank 3. Electric valves 12 and flow meters 13 are arranged on the inlet and outlet pipelines of the storage tank 1, the flocculation tank 2 and the advanced oxidation tank 3. Centrifugal pumps 14 are arranged on the outlet pipelines of the storage tank 1, the flocculation tank 2, the advanced oxidation tank 3 and the collecting tank 6. Electric valves 12 are arranged on the pipelines connecting the adsorption tower 4, the resin ion exchange column 5 and the collecting tank 6 and on the outlet pipeline of the collecting tank 6. The coagulation unit is used to remove most of the suspended matter and a small amount of COD; the advanced oxidation unit is used to remove most of the COD; the adsorption and hardness removal unit is used to remove calcium and magnesium ions; the three-effect evaporation supporting device 7 is used to concentrate and reduce the wastewater. The evaporation heat source of the three-effect evaporation supporting device 7 is high-temperature industrial waste gas, and the produced water is reused for industrial water. Specifically, the three-effect multi-stage evaporator receives waste water sent from the outlet pipeline of the collection tank 6, and the mixed salt produced after three-stage evaporation and concentration is further separated, purified or incinerated according to its practical value; the tail steam produced is discharged to the tail gas condenser 8, cooled by external cooling water, and then stored in the water production tank 9 for use as industrial water.

[0030] The advanced oxidation tank 3 adopts the Fenton oxidation method. The oxidant added in the Fenton oxidation method is one or more of H2O2, FeSO4, etc. The specific combination and proportion can be adjusted according to the different COD contents in the wastewater.

[0031] Embodiment 1:

[0032] The wastewater was taken from a coking plant in Taiyuan, and it was brown in color. The quality of the raw water is shown in Table 1.

[0033] Table 1 Water quality of the wastewater from a coking plant

[0034] project SS(mg / L) COD(mg / L) <![CDATA[Ca 2+ (mg / L)]]> <![CDATA[Mg 2+ (mg / L)]]> Raw water quality 2561 9731 996 3800

[0035] The high-salinity wastewater is stored in the storage tank 1. The outlet pipe of the storage tank 1 is operated as follows: the centrifugal pump 14 is turned on, and the opening of the electric valve 12 is adjusted so that the flow meter 13 reads 1m / s. 3 / h, start the agitator 11 inside the flocculation tank 2, open the flocculant addition port of the flocculation tank 2, and perform the following operations on the inlet end pipeline of the flocculation tank 2: adjust the electric valve 12 so that the flow meter 13 reads 220g / h, and add flocculant (the mass ratio of polyaluminium chloride and polyacrylamide is 10:1);

[0036] The following operations are performed on the outlet pipeline of the flocculation tank 2: start the centrifugal pump 14, adjust the opening of the electric valve 12, and make the flow meter 13 read 1m 3 / h, start the agitator 11 inside the flocculation tank 2, open the oxidant addition port of the advanced oxidation tank 3, and perform the following operations on the inlet end pipeline of the advanced oxidation tank 3: adjust the electric valve 12 so that the flow meter 13 reads 31.2m 3 / h, adding oxidant (mass ratio of hydrogen peroxide to ferrous sulfate is 1:14);

[0037] The outlet pipeline of the advanced oxidation tank 3 is operated as follows: the centrifugal pump 14 is turned on, and the opening of the electric valve 12 is adjusted so that the flow meter 13 reads 1m 3 / h, the wastewater passes through the adsorption tower 4 and the resin exchange column in turn, and the treated wastewater enters the collection tank 6, and is sent to the three-effect evaporation supporting device 7 through the centrifugal pump 14 on the outlet pipeline of the collection tank 6 for evaporation and concentration.

[0038] According to the treatment method of this embodiment, the turbidity removal rate reaches 96.1%, the COD removal rate reaches 89%, and the calcium and magnesium ion removal rates reach 97.6% and 95% respectively. The water quality analysis in the collection tank 6 is shown in Table 2.

[0039] Table 2 Water quality indicators in the collection tank of Example 1

[0040] project SS(mg / L) COD(mg / L) <![CDATA[Ca 2+ (mg / L)]]> <![CDATA[Mg 2+ (mg / L)]]> Water output results 99.8 1070 24 190 Removal rate 96.1％ 89％ 97.6％ 95％

[0041] Embodiment 2:

[0042] The wastewater was taken from a solid waste treatment station in Taiyuan. It was light green in color, contained a large amount of black suspended matter, and had high viscosity. The quality of the raw water is shown in Table 3.

[0043] Table 3 Water quality of the raw wastewater from a solid waste treatment station

[0044] project SS(mg / L) COD(mg / L) <![CDATA[Ca 2+ (mg / L)]]> <![CDATA[Mg 2+ (mg / L)]]> Raw water quality 5013 6215 15120 5400

[0045] The high-salinity wastewater is stored in the storage tank 1. The outlet pipe of the storage tank 1 is operated as follows: the centrifugal pump 14 is turned on, and the opening of the electric valve 12 is adjusted so that the flow meter 13 reads 1m / s. 3 / h, start the agitator 11 inside the flocculation tank 2, open the flocculant addition port of the flocculation tank 2, and perform the following operations on the inlet end pipeline of the flocculation tank 2: adjust the electric valve 12 so that the flow meter 13 reads 366.3g / h and add flocculant (the mass ratio of polyaluminium ferric silicate to modified starch is 13:3);

[0046] The following operations are performed on the outlet pipeline of the flocculation tank 2: start the centrifugal pump 14, adjust the opening of the electric valve 12, and make the flow meter 13 read 1m 3 / h, start the agitator 11 inside the flocculation tank 2, open the oxidant addition port of the advanced oxidation tank 3, and perform the following operations on the inlet end pipeline of the advanced oxidation tank 3: adjust the electric valve 12 so that the flow meter 13 reads 18.8m 3 / h adding oxidant (mass ratio of hydrogen peroxide to ferrous sulfate is 1:12);

[0047] The outlet pipeline of the advanced oxidation tank 3 is operated as follows: the centrifugal pump 14 is turned on, and the opening of the electric valve 12 is adjusted so that the flow meter 13 reads 1m 3 / h, the wastewater passes through the adsorption tower 4 and the resin exchange column in turn, and the treated wastewater enters the collection tank 6, and is sent to the three-effect evaporation supporting device 7 through the centrifugal pump 14 on the outlet pipeline of the collection tank 6 for evaporation and concentration.

[0048] According to the treatment method of this embodiment, the turbidity removal rate reaches 97.4%, the COD removal rate is 87%, and the calcium and magnesium ion removal rates are 91% and 93.6% respectively. The water quality analysis in the collection tank 6 is shown in Table 4.

[0049] Table 4 Water quality indexes in the collection tank of Example 2

[0050] project SS(mg / L) COD(mg / L) <![CDATA[Ca 2+ (mg / L)]]> <![CDATA[Mg 2+ (mg / L)]]> Water output results 130 808 1360 345 Removal rate 97.4％ 87％ 91％ 93.6％

[0051] The above embodiments are not limited to the technical solutions of the embodiments themselves, and the embodiments can be combined with each other to form new embodiments. The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Any modification or equivalent replacement that does not deviate from the spirit and scope of the present invention shall be included in the scope of the technical solutions of the present invention.

Claims

1. An energy-saving universal high-salinity wastewater treatment system, characterized by: The invention comprises a storage tank (1), a flocculation tank (2), an advanced oxidation tank (3), an adsorption tower (4), a resin ion exchange column (5), a collection tank (6) and a triple-effect evaporation supporting device (7). The inlet pipeline of the storage tank (1) is connected to the raw water of high-salinity wastewater, and the outlet pipeline is connected to the flocculation tank (2); the inlet pipeline of the flocculation tank (2) is connected to the flocculant, and the outlet pipeline is connected to the advanced oxidation tank (3); the inlet pipeline of the advanced oxidation tank (3) is connected to the oxidant, and the outlet pipeline of the advanced oxidation tank (3) is connected to the adsorption tower (4). The outlet pipeline of the resin ion exchange column (5) is connected to the collecting tank (6). The three-effect evaporation supporting device (7) is composed of a three-effect multi-stage evaporator, a tail gas condenser (8), and a water production storage tank (9). The outlet pipeline of the collecting tank (6) is connected to the three-effect multi-stage evaporator. The discharge pipelines of the storage tank (1), the flocculation tank (2), and the advanced oxidation tank (3) are commonly connected to a sludge concentration tank (10). The flocculation tank (2) and the advanced oxidation tank (3) are provided with a stirrer (11). The storage tank (1), the flocculation tank (2 ) and the inlet and outlet pipes of the advanced oxidation tank (3) are all provided with electric valves (12) and flow meters (13); the flocculant added to the flocculation tank (2) is an organic-inorganic composite flocculant, the organic flocculant includes polyacrylamide and starch-based flocculant, the inorganic flocculant includes polyaluminium chloride, polyaluminium chloride iron and polyaluminium silicate iron; the adsorption tower (4) is added with lime-sodium carbonate solution; the resin ion exchange column (5) uses a super cross-linked chloromethylated resin modified with thiopropionamide; the flocculation tank (2) and the flocculant are connected to the adsorption tower (4); The flowmeter (13) on the connected inlet pipeline is a solid flowmeter, the oxidant is one or more of H2O2 and FeSO4, the outlet pipelines of the storage tank (1), the flocculation tank (2), the advanced oxidation tank (3) and the collection tank (6) are all provided with a centrifugal pump (14), the pipelines connecting the adsorption tower (4), the resin ion exchange column (5) and the collection tank (6) and the outlet pipeline of the collection tank (6) are all provided with an electric valve (12), and the evaporation heat source of the triple-effect evaporation supporting device (7) is industrial high-temperature waste gas.

2. An application method of the energy-saving universal high-salinity wastewater treatment system of claim 1, characterized in that: The steps include: S1. The high-salinity wastewater is stored in a storage tank (1), and the outlet pipe of the storage tank (1) is operated as follows: the centrifugal pump (14) is started to pump the wastewater into the flocculation tank (2), the agitator (11) in the flocculation tank (2) is started, and a flocculant is added to the flocculation tank (2); S2. The outlet pipeline of the flocculation tank (2) is operated as follows: the centrifugal pump (14) is started to send the supernatant in the flocculation tank (2) into the advanced oxidation tank (3), the agitator (11) in the advanced oxidation tank (3) is started, and the oxidant is added into the advanced oxidation tank (3); S3. The outlet pipeline of the advanced oxidation tank (3) is operated as follows: the centrifugal pump (14) is started to send the supernatant in the advanced oxidation tank (3) into the adsorption tower (4), the liquid after the reaction enters the resin exchange column, and the liquid after the reaction in the resin exchange column enters the collection tank (6); S4. Start the centrifugal pump (14) on the outlet pipeline of the collection tank (6) to send the liquid in the collection tank (6) into the triple-effect evaporation supporting device (7) for evaporation and concentration; S5. The mixed salt concentrated in step S4 is further separated, purified or incinerated according to its practical value, and the condensed water generated during the evaporation process is reused as industrial water; S6. After the reaction is completed, the outlets of the storage tank (1), the flocculation tank (2), and the advanced oxidation tank (3) are opened to discharge the sludge into the sludge thickening tank (10).

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