A deionized water production wastewater recycling and treatment system

Abstract

This utility model belongs to the field of wastewater treatment technology, specifically relating to a wastewater recycling and treatment system for deionized water production. It includes a wastewater tank and a finished water tank, with a sedimentation device and a filtration device installed between them. A resin softener and a concentration device are also installed between the wastewater tank and the finished water tank. Wastewater in the wastewater tank sequentially passes through the sedimentation device, filtration device, resin softener, and concentration device before flowing into the finished water tank. This utility model, by adding a resin softener and a concentration device to the existing sedimentation and filtration devices, constructs a multi-stage treatment system of "sedimentation-filtration-softening-concentration," deeply removing impurities from the wastewater and improving the water resource recovery rate.

Description

Technical Field

[0001] This utility model belongs to the field of wastewater treatment technology, specifically relating to a system for recycling and treating production wastewater from deionized water production. Background Technology

[0002] Deionized water is primarily used as an electrolyte in caustic soda production. During electrolysis, caustic soda, chlorine gas, and hydrogen gas are generated through an electrochemical reaction. The high purity of deionized water helps improve the quality of caustic soda. During electrolysis, the high purity of deionized water reduces the impact of impurities on the reaction process, thus ensuring higher quality caustic soda is produced.

[0003] However, the deionized water preparation process inevitably generates two main types of wastewater: one is the concentrated water produced by the reverse osmosis process, which contains high concentrations of inorganic salts, suspended solids, and organic matter; the other is the acidic and alkaline wastewater generated during the resin tower regeneration process, which contains a large amount of H+. + OH - Pollutants such as ions.

[0004] Currently, most companies typically discharge wastewater directly after simple neutralization and sedimentation. However, this treatment method not only leads to a large waste of water resources, but also causes ecological problems such as salinity imbalance and abnormal pH value in the untreated wastewater due to its high salt and acid / alkaline content, which endangers environmental safety. Utility Model Content

[0005] To address the problems existing in the prior art, this utility model provides a wastewater recycling and treatment system for deionized water production. By adding a resin softener and a concentration device to the existing sedimentation and filtration devices, a multi-stage treatment system of "sedimentation-filtration-softening-concentration" is constructed to deeply remove impurities from the wastewater and improve the water resource recovery rate.

[0006] The specific technical solution adopted in this utility model is as follows:

[0007] A wastewater recycling and treatment system for deionized water production includes a wastewater tank and a finished water tank. A sedimentation device and a filtration device are installed between the wastewater tank and the finished water tank. A resin softener and a concentration device are also installed between the wastewater tank and the finished water tank. The wastewater in the wastewater tank passes through the sedimentation device, the filtration device, the resin softener and the concentration device in sequence and flows into the finished water tank.

[0008] The precipitation device includes a NaOH precipitation tank, a Na2CO3 precipitation tank, and a flocculation tank. The output end of the wastewater tank is connected to the liquid phase input end of the NaOH precipitation tank, the liquid phase output end of the NaOH precipitation tank is connected to the liquid phase input end of the Na2CO3 precipitation tank, and the liquid phase output end of the Na2CO3 precipitation tank is connected to the liquid phase input end of the flocculation tank. The liquid phase output end of the flocculation tank forms the output end of the precipitation device and is connected to the filtration device.

[0009] A first conveying pipe is also provided between the NaOH precipitation tank and the Na2CO3 precipitation tank, through which the precipitate in the NaOH precipitation tank is transported to the Na2CO3 precipitation tank. A second conveying pipe is also provided between the NaOH precipitation tank and the flocculation tank, through which the flocculent matter in the flocculation tank is transported to the NaOH precipitation tank.

[0010] The filtration device includes a sand filter and an ultrafiltration membrane filter. The input end of the sand filter is formed as the input end of the filtration device and is connected to the output end of the sedimentation device. The input end of the ultrafiltration membrane filter is connected to the output end of the sand filter, and the output end of the ultrafiltration membrane filter is formed as the output end of the filtration device and is connected to the resin softener.

[0011] The concentration device includes a primary concentration tank and a secondary concentration tank. The input end of the primary concentration tank is formed as the input end of the concentration device and is connected to the output end of the resin softener. The input end of the secondary concentration tank is connected to the output end of the primary concentration tank. The finished water output end of the secondary concentration tank is connected to the finished water tank.

[0012] The bottom of the secondary concentration tank is also provided with a concentrate output end, which is connected to the concentrate pool.

[0013] Both the primary and secondary concentration tanks are equipped with a circulation outlet and a circulation inlet. The circulation outlet of the primary concentration tank is connected to the circulation inlet of the primary concentration tank via a primary circulation pump, and the circulation outlet of the secondary concentration tank is connected to the circulation inlet of the secondary concentration tank via a secondary circulation pump.

[0014] The beneficial effects of this utility model are:

[0015] 1. This utility model adds a resin softener and a concentration device to the sedimentation device and the filtration device, and constructs a multi-stage treatment system of "sedimentation-filtration-softening-concentration" to deeply remove impurities in wastewater and improve the water resource recovery rate.

[0016] The sedimentation unit removes most of the calcium and magnesium ions from the raw water through sedimentation, and the supernatant enters the filtration unit, where most of the suspended solids in the raw water are removed. Then, it enters the resin softener to completely remove the calcium and magnesium ions from the raw water, reducing the water hardness. The concentration unit uses membrane concentration technology to deeply treat the wastewater, converting the recyclable water in the wastewater into finished water that meets the standards for primary water entering the enterprise. This significantly improves water resource utilization, achieving a primary water saving rate of ≥20% and reducing wastewater discharge by 90%, thus achieving the goal of water conservation and emission reduction and lowering the enterprise's production costs.

[0017] 2. In this utility model, a portion of the metal hydroxides generated in the NaOH precipitation tank are sent to the Na2CO3 precipitation tank through the first conveying pipe, providing a nucleus carrier for carbonate precipitation, thereby improving the precipitation efficiency of calcium and magnesium ions; at the same time, a portion of the flocculent material in the flocculation tank is returned to the NaOH precipitation tank through the second conveying pipe, and the adsorption effect of the flocculent material is used to enhance the initial precipitation effect of heavy metal ions and improve the sedimentation rate of impurities in wastewater. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the system of this utility model. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0020] Specific embodiments, such as Figure 1 As shown, this utility model provides a wastewater recycling and treatment system for deionized water production, including a wastewater tank and a finished water tank. A sedimentation device and a filtration device are provided between the wastewater tank and the finished water tank. A resin softener and a concentration device are also provided between the wastewater tank and the finished water tank. The wastewater in the wastewater tank passes through the sedimentation device, the filtration device, the resin softener and the concentration device in sequence and flows into the finished water tank.

[0021] Currently, most companies typically discharge wastewater directly after simple neutralization and sedimentation. However, this treatment method not only leads to a large waste of water resources, but also causes ecological problems such as salinity imbalance and abnormal pH value in the untreated wastewater due to its high salt and acid / alkaline content, which endangers environmental safety.

[0022] Therefore, this invention adds a resin softener and a concentration device to the sedimentation device and filtration device, thus constructing a multi-stage treatment system of "sedimentation-filtration-softening-concentration" to deeply remove impurities from wastewater and improve the water resource recovery rate.

[0023] The sedimentation unit removes most of the calcium and magnesium ions from the raw water through sedimentation, and the supernatant enters the filtration unit, where most of the suspended solids in the raw water are removed. Then, it enters the resin softener to completely remove the calcium and magnesium ions from the raw water, reducing the water hardness. The concentration unit uses membrane concentration technology to deeply treat the wastewater, converting the recyclable water in the wastewater into finished water that meets the standards for primary water entering the enterprise. This significantly improves water resource utilization, achieving a primary water saving rate of ≥20% and reducing wastewater discharge by 90%, thus achieving the goal of water conservation and emission reduction and lowering the enterprise's production costs.

[0024] The precipitation device includes a NaOH precipitation tank, a Na2CO3 precipitation tank, and a flocculation tank. The output end of the wastewater tank is connected to the liquid phase input end of the NaOH precipitation tank, the liquid phase output end of the NaOH precipitation tank is connected to the liquid phase input end of the Na2CO3 precipitation tank, and the liquid phase output end of the Na2CO3 precipitation tank is connected to the liquid phase input end of the flocculation tank. The liquid phase output end of the flocculation tank forms the output end of the precipitation device and is connected to the filtration device.

[0025] This invention employs a dual-alkali sedimentation method to remove most of the calcium and magnesium ions from the raw water. First, in the NaOH sedimentation tank, the pH value is adjusted to cause the heavy metal ions to form hydroxide precipitates. Then, the water enters the Na2CO3 sedimentation tank to further remove calcium and magnesium ions, forming carbonate precipitates. Finally, the water enters the flocculation tank, where flocculants are added to aggregate the tiny suspended solids into large flocs, achieving graded and gradual removal of different pollutants. This avoids the problem of incomplete removal caused by the complexity of pollutants in a single sedimentation process.

[0026] A first conveying pipe is also provided between the NaOH precipitation tank and the Na2CO3 precipitation tank, through which the precipitate in the NaOH precipitation tank is transported to the Na2CO3 precipitation tank. A second conveying pipe is also provided between the NaOH precipitation tank and the flocculation tank, through which the flocculent matter in the flocculation tank is transported to the NaOH precipitation tank.

[0027] In this invention, a portion of the metal hydroxides generated in the NaOH precipitation tank are sent to the Na2CO3 precipitation tank via a first conveying pipe, providing a nucleus carrier for carbonate precipitation and thus improving the precipitation efficiency of calcium and magnesium ions. At the same time, a portion of the flocculent material from the flocculation tank is returned to the NaOH precipitation tank via a second conveying pipe, utilizing the adsorption effect of the flocculents to enhance the initial precipitation effect of heavy metal ions and improve the sedimentation rate of impurities in wastewater.

[0028] The filtration device includes a sand filter and an ultrafiltration membrane filter. The input end of the sand filter is formed as the input end of the filtration device and is connected to the output end of the sedimentation device. The input end of the ultrafiltration membrane filter is connected to the output end of the sand filter, and the output end of the ultrafiltration membrane filter is formed as the output end of the filtration device and is connected to the resin softener.

[0029] This invention employs a dual filtration method of sand filtration and ultrafiltration. The sand filter removes large suspended solids and colloids, while the ultrafiltration membrane filter traps tiny suspended solids, bacteria, and some organic matter, forming a gradient filtration system from coarse filtration to fine filtration.

[0030] The concentration device includes a primary concentration tank and a secondary concentration tank. The input end of the primary concentration tank is formed as the input end of the concentration device and is connected to the output end of the resin softener. The input end of the secondary concentration tank is connected to the output end of the primary concentration tank. The finished water output end of the secondary concentration tank is connected to the finished water tank.

[0031] The bottom of the secondary concentration tank is also provided with a concentrate output end, which is connected to the concentrate pool.

[0032] In this invention, wastewater is concentrated and reduced by about 5 times in the primary concentration tank, and about 55% of the product water is recovered in the secondary concentration tank and sent to the finished water pool. The concentrated water is concentrated by about 2.2 times and sent to the concentrated water pool for use as a salt dispensing water, thus realizing the cascade utilization of water resources.

[0033] Both the primary and secondary concentration tanks are equipped with a circulation outlet and a circulation inlet. The circulation outlet of the primary concentration tank is connected to the circulation inlet of the primary concentration tank via a primary circulation pump, and the circulation outlet of the secondary concentration tank is connected to the circulation inlet of the secondary concentration tank via a secondary circulation pump.

[0034] The concentration ratio of wastewater can be controlled by a circulating pump to adapt to different water quality and quantity treatment needs.

Claims

1. A wastewater recycling and treatment system for deionized water production, comprising a wastewater tank and a finished water tank, wherein a sedimentation device and a filtration device are provided between the wastewater tank and the finished water tank, characterized in that, A resin softener and a concentration device are also installed between the wastewater tank and the finished water tank. The wastewater in the wastewater tank passes through a sedimentation device, a filtration device, a resin softener and a concentration device in sequence before flowing into the finished water tank.

2. The wastewater recycling and treatment system for deionized water production according to claim 1, characterized in that, The precipitation device includes a NaOH precipitation tank, a Na2CO3 precipitation tank, and a flocculation tank. The output end of the wastewater tank is connected to the liquid phase input end of the NaOH precipitation tank, the liquid phase output end of the NaOH precipitation tank is connected to the liquid phase input end of the Na2CO3 precipitation tank, and the liquid phase output end of the Na2CO3 precipitation tank is connected to the liquid phase input end of the flocculation tank. The liquid phase output end of the flocculation tank forms the output end of the precipitation device and is connected to the filtration device.

3. The wastewater recycling and treatment system for deionized water production according to claim 2, characterized in that, A first conveying pipe is also provided between the NaOH precipitation tank and the Na2CO3 precipitation tank, through which the precipitate in the NaOH precipitation tank is transported to the Na2CO3 precipitation tank. A second conveying pipe is also provided between the NaOH precipitation tank and the flocculation tank, through which the flocculent matter in the flocculation tank is transported to the NaOH precipitation tank.

4. The wastewater recycling and treatment system for deionized water production according to claim 1, characterized in that, The filtration device includes a sand filter and an ultrafiltration membrane filter. The input end of the sand filter is formed as the input end of the filtration device and is connected to the output end of the sedimentation device. The input end of the ultrafiltration membrane filter is connected to the output end of the sand filter, and the output end of the ultrafiltration membrane filter is formed as the output end of the filtration device and is connected to the resin softener.

5. The wastewater recycling and treatment system for deionized water production according to claim 1, characterized in that, The concentration device includes a primary concentration tank and a secondary concentration tank. The input end of the primary concentration tank is formed as the input end of the concentration device and is connected to the output end of the resin softener. The input end of the secondary concentration tank is connected to the output end of the primary concentration tank. The finished water output end of the secondary concentration tank is connected to the finished water tank.

6. The wastewater recycling and treatment system for deionized water production according to claim 5, characterized in that, The bottom of the secondary concentration tank is also provided with a concentrate output end, which is connected to the concentrate pool.

7. The wastewater recycling and treatment system for deionized water production according to claim 5, characterized in that, Both the primary and secondary concentration tanks are equipped with a circulation outlet and a circulation inlet. The circulation outlet of the primary concentration tank is connected to the circulation inlet of the primary concentration tank via a primary circulation pump, and the circulation outlet of the secondary concentration tank is connected to the circulation inlet of the secondary concentration tank via a secondary circulation pump.

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