CN-117383727-B - New technology for realizing coal chemical industry wastewater hardness removal by in-situ alkali preparation method

Abstract

The application discloses a novel process for realizing the hardness removal of coal chemical wastewater by an in-situ alkali preparation method, which comprises a crystallization process section, an in-situ alkali preparation process section and a water quality regulation process section, wherein the coupling process has advancement and linkage in the sequence of the process, the one-step hardness removal is realized by coupling the crystallization process section and the in-situ alkali preparation process section according to the sequence, ions are not added in water, the problem of equipment scaling and blocking can be effectively solved, the equipment can stably run for a long period, the alkali required by a system is generated by utilizing salt in water, the hardness in water is removed by utilizing the alkali prepared by the system, and the excessive salt in the system can be recycled. The coupling of the two uses the hardness removal function of the columnar grain type crystallization micro-reactor to meet the optimal water inlet condition of in-situ alkali preparation, and uses the alkali produced by the in-situ alkali preparation generator to remove the hardness, and the two are mutually dependent and mutually complemented, so that the optimal coupling of the process is realized, and the respective optimal performances of the two are exerted.

Inventors

• Ji Keyao
• JI BAOJIANG

Assignees

• 大连东道尔膜技术有限公司

Dates

Publication Date

20260512

Application Date

20230823

Claims (5)

1. 1. A novel process for realizing the hardness removal of coal chemical wastewater by an in-situ alkali preparation method is characterized by comprising a crystallization process section, an in-situ alkali preparation process section and a water quality regulation process section; raw water passes through a crystallization process section to remove suspended matters, turbidity and hardness; The anode product is acid solution under the drive of an external electric field in the in-situ alkali preparation process section and serves as an acid solution source of the water quality adjusting process section; The water quality adjusting process section mixes the produced water of the crystallization process section with the acid solution of the in-situ alkali making process section, and the pH value in the raw water is adjusted back; the crystallization process section is coupled with the in-situ alkali preparation process section, water produced by the crystallization process section is a prerequisite for water inlet of the in-situ alkali preparation process section, the produced water is sent to the in-situ alkali preparation process section to prepare acid and alkali, and the produced alkali liquid is sent back to the crystallization process section to remove the hardness in the water; the crystallization process section comprises a 1-grade column particle reaction process section, a 2-grade column particle reaction process section and a 3-grade column particle reaction process section which are sequentially arranged, wherein 60-80-mesh crystal nucleus magnetic powder is filled in each of the 1-grade column particle reaction process sections, raw water enters the 1-grade column particle reaction process section, na 2 SO 4 solution is added to generate CaSO 4 and is crystallized on the magnetic powder to form particles, water produced in the 1-grade column particle reaction process section enters the 2-grade column particle reaction process section and reacts with NaOH solution to generate Mg (OH) 2 crystals on solid particles, water produced in the 2-grade column particle reaction process section enters the 3-grade column particle reaction process section, naOH solution and CO 2 gas are added into the 3-grade column particle reaction process section to generate CaCO 3 crystals on the solid particles, and the 3-grade column particle reaction process section reacts with NaOH solution to generate Mg (OH) 2 crystals on the solid particles One part of the produced water enters a salt separation concentration process section, and the other part enters a water quality regulation process section; the water produced in the 3-stage column particle reaction process section is subjected to salt separation and concentration to obtain monovalent salt solution and divalent salt solution, wherein the monovalent salt solution is used as raw material liquid in the in-situ alkali preparation process section, and the divalent salt solution is used as liquid medicine added in the 1-stage column particle reaction process section.
2. 2. The novel process for realizing the hardness removal of the coal chemical wastewater by the in-situ alkali preparation method according to claim 1, wherein the salt separation concentration process section comprises an RO technology, an electrodialysis technology and an evaporation technology, the produced water of the crystallization process section passes through the salt separation concentration process section to obtain a monovalent salt solution and a divalent mixed salt solution, the monovalent salt solution is concentrated to be used as a stock solution of the in-situ alkali preparation process section, and the divalent mixed salt solution is used as a precipitant of the 1-stage column particle reaction process section.
3. 3. The novel process for realizing the hardness removal of the coal chemical wastewater by the in-situ alkaline process according to claim 1, wherein the crystallization process section comprises a multistage columnar grain type crystallization microreactor.
4. 4. The novel process for realizing the hardness removal of the coal chemical wastewater by the in-situ alkaline process according to claim 1, wherein the salt separation concentration process section is realized by a porous electrode ion membrane enrichment technology.
5. 5. The novel process for realizing the hardness removal of the coal chemical wastewater by the in-situ alkaline preparation method according to claim 1, wherein the in-situ alkaline preparation process section is realized by a porous electrode ion membrane alkaline preparation technology.

Description

New technology for realizing coal chemical industry wastewater hardness removal by in-situ alkali preparation method Technical Field The invention relates to the technical field of wastewater treatment, in particular to a novel process for realizing coal chemical wastewater hardness removal by an in-situ alkaline process. Background The wastewater produced in the coal chemical industry is headache in wastewater treatment in the coal chemical industry due to the problems of complex components, high suspended matter content, high hardness, serious scaling and the like. How to realize the recycling of the coal chemical wastewater becomes a very urgent subject. At present, the coal chemical wastewater hardness removal generally adopts the following processes: The double-alkali method is characterized in that the process equipment generally adopts a high-density tank, a high-efficiency sedimentation tank, a coagulating sedimentation tank, granulation and hardness removal and the like, and is characterized in that excessive alkali agent is required to be added, the produced water is adjusted back to the PH value, but the accuracy requirement on a system dosing device and an analysis instrument is high, the instantaneous dosing amount and the water quality fluctuation of actual production are not matched in time, the fluctuation of the produced water quality of the device is large, the water outlet index is unstable, scaling is easy, and the stable operation of a follow-up device is further influenced. The electrochemical method comprises an electric flocculation technology, an electrolytic descaling technology and the like, wherein the technologies can remove hardness, but the single equipment has low processing capacity and low hardness removal efficiency, and the chemical agents such as alkali liquor and the like are needed to be added, so that the pH of produced water is needed to be regulated, the quality of the effluent water is unstable, the electrode is easy to scale, the maintenance is complex, and the chemical agent cost is high. The ion exchange method has higher requirements on suspended matters, COD, water temperature, hardness and heavy metal ions of the inlet water, needs pretreatment to prevent resin pollution and poisoning, needs cooling the waste water, otherwise, influences the service life of the resin, even causes the damage of the resin, needs to configure an acid-base storage system, and simultaneously generates a large amount of high-salt waste liquid. The membrane method can remove hardness, but the water inlet of the membrane device cannot exceed 45 ℃, a heat exchange system is required to be equipped, and cooling water and a perfect pretreatment system are arranged, so that the membrane method has the advantages of more supporting facilities, complex management, high automatic investment, large occupied area of the system and low engineering reliability. Disclosure of Invention The invention aims to provide a novel process for realizing the hardness removal of coal chemical wastewater by an in-situ alkali preparation method, wherein alkali required by a salt generation system in water is utilized, the hardness in the water is removed by utilizing the produced alkali, front and rear systems are coupled and matched with each other, the scaling and blocking of the system are avoided, the stability and the continuity of equipment are improved, and the excessive salt in the system can be recycled. In order to achieve the aim, the technical scheme of the application is that a novel process for realizing the hardness removal of the coal chemical wastewater by an in-situ alkali preparation method comprises a crystallization process section, an in-situ alkali preparation process section and a water quality regulation process section; raw water passes through a crystallization process section to remove suspended matters, turbidity and hardness; The anode product is acid solution under the drive of an external electric field in the in-situ alkali preparation process section and serves as an acid solution source of the water quality adjusting process section; The water quality adjusting process section mixes the produced water of the crystallization process section with the acid solution of the in-situ alkali making process section, and the PH value in the raw water is adjusted back. The crystallization process section is coupled with the in-situ alkali preparation process section, water produced by the crystallization process section is a prerequisite for water inlet of the in-situ alkali preparation process section, fouling and blocking of equipment are avoided, the produced water is sent to the in-situ alkali preparation process section to prepare acid and alkali, and the produced alkali liquid is sent back to the crystallization process section to remove hardness in the water. Further, the crystallization process section comprises a 1-grade column particle reaction process section, crystal nucle