How to deal with calcium and magnesium in the water after sewage treatment

Removal is, how much is the content, and different methods are used for different contents.

Calcium chloride has the following functions in wastewater treatment:

1., sewage treatment agent for pH neutralization.

2. Disinfection and sterilization: Chloride ions dissolved in water have the effect of disinfection and disinfection.

3. Wastewater treatment as a filter aid.

Extended information: Chloride ions can sterilize and disinfect water, kill harmful bacteria, and reduce the toxicity of water; Calcium ions can replace the metal cations contained in the water, separate and discharge the toxic heavy metal ions, and exclude the precipitation of calcium ions.

The barrier method is to pass water through the filter media so that larger impurities cannot pass through, so as to obtain cleaner water. In addition, the physical method also includes the precipitation method, which allows the heavier impurities to float on the surface of the water, fishes out, and precipitates the heavier impurities below, and then obtains; The chemical method is to use various chemicals to convert the impurities in the water into substances that are less harmful to the human body, or to concentrate the impurities.

The methods of water treatment include physical treatment and chemical treatment. Physical method - the use of a variety of pore size of different size of the filter material, the use of adsorption or barrier mode, the use of impurities in the water, the more important adsorption method is activated carbon adsorption, the barrier method is to pass the water through the filter material, so that the larger volume of impurities can not pass, and then obtain cleaner water. In addition, the physical method also includes the precipitation method, which is to let the impurities with a small specific gravity float on the surface of the water and fish out, or the impurities with a large specific gravity are precipitated below, and then obtained.

The chemical method is to use a variety of chemicals to convert the impurities in the water into substances that are less harmful to the human body, or to concentrate the impurities, the oldest chemical treatment method should be regarded as adding alum to the water, after the impurities in the water are collected, the volume becomes larger, and the impurities can be removed by filtration.

It is used for winter snow removal on roads, highways, parking lots, airports, golf courses, etc.;

2. Calcium chloride is used as a dehydrating agent for oil drilling, drilling fluid, completion fluid, petrochemical industry, etc.;

3. Anhydrous calcium chloride is used to prevent dust, coal dust and mineral dust;

4. In the construction industry, calcium chloride is used as an early strength agent (to improve the strength of concrete) and a coagulant for the production of coatings;

5. In the drying industry, calcium chloride is used as a desiccant, such as a desiccant for moisture-proofing, and a drying medium for gas and liquid in the process;

6. In the rubber industry, calcium chloride dihydrate is used as a latex coagulant;

7. In the ferrous metallurgy industry, calcium chloride is used as a chlorinating agent and additive;

8. In the paper industry, it is used as an additive (to increase the strength of paper) and a waste paper deinking agent;

9. In the field of inorganic chemical raw materials in the chemical industry, calcium chloride is used as a remover for sulfate and a coagulant for sodium alginate;

10. Refrigeration industry, air conditioning system for refrigeration (cooling solution and process gas and liquid);

11. Agricultural use of calcium chloride: prevention and control of corn.

12. Used in the production of dyes and printing and dyeing industry;

13. In the production process of organic chemical industry, calcium chloride is used as an additive for distilled petroleum and ether alcohol;

14. In swimming pool water, adding calcium chloride can make the pool water become a pH buffer solution and increase the hardness of the pool water at the same time, which can reduce the erosion of the pool wall concrete;

15. Adding calcium chloride to the water of the oceanarium can increase the content of bioavailable calcium in the water, and the molluscs and coelenterates bred in the aquarium will use it to form the shell of calcium carbonate;

16. The role of food-grade calcium chloride: as a food preservative, it helps to maintain the freshness of food; Pasteurized milk loses a lot of calcium during processing, and the addition of a small amount of calcium chloride, which is also an important additive for cheese, can help coagulation.

17. Calcium chloride is also an additive in plastics and fire extinguishers, used as a filter aid in wastewater treatment, and as an additive in blast furnace to control the aggregation and adhesion of raw materials to avoid charge sedimentation, and play the role of a diluent in fabric softeners.

18. In the petroleum industry, calcium chloride is used to increase the density of solid-free brine, and can also be added to the aqueous phase of emulsified drilling fluid to inhibit the expansion of clay.

1. Sewage treatment agent: We need to use calcium hydroxide to carry out pH medium and pre-acidic sewage pipe network, so as to extend the use time of the pipe network, which greatly saves the country's investment cost. The aqueous solution of calcium hydroxide has strong alkalinity, which can neutralize the acidic wastewater first and then discharge it, which plays a role in protecting the service life of the groundwater pipeline;

2. Acid water treatment agent; Calcium hydroxide has the effect of coagulation and precipitation and acid neutralization, and we use it to remove anions such as phosphate and sulfate in practical applications.

In addition, when the water contains salts such as calcium chloride and calcium sulfate, the solubility of calcium fluoride is reduced due to the ionic effect, and the fluorine concentration can also be reduced to less than 10mg l or even below the theoretical solubility of calcium fluoride through first-class lime treatment.

The role of calcium chloride in sewage treatment is mainly the role of a precipitant, which can precipitate some carbonate ions in water.

Haircut cover in sewage treatment, I think it should play a role.

It is mainly calcium ions that play a role and combine with carbonate ions, or hydroxide ions to form precipitates.

There may be two reasons for the high calcium and magnesium ions in sewage treatment:

1) The sewage before treatment contains a large amount of calcium and magnesium ions.

2) In the process of sewage treatment, a large amount of neutralizing agents such as calcium carbonate or magnesium hydroxide are used to neutralize the pH value.

If calcium ions and magnesium ions are not afraid, add some sodium carbonate and sodium hydroxide to form calcium and magnesium ions into calcium carbonate and basic magnesium carbonate and precipitate them.

1.Calcium chloride.

Chloride ions dissolved in water have the effect of sterilization and disinfection, while calcium ions can replace metal cations in water.

Especially in the wastewater treatment process containing metal cations, in order to reduce the damage of metal cations and some highly toxic substances to the biochemical section, calcium chloride is used to remove these toxic and harmful substances in the pretreatment process, and if this substance is used in the effluent section, chloride ions play a sterilizing role, and calcium ions generate calcium hydroxide.

The precipitation is removed by the precipitation.

2.Calcium chloride, chemical formula CaCl2 2H20 white crystals or lumps. Melting point 782, boiling point 1600, density gram cm, can form a hydrate containing crystal water, colorless cubic crystal, white or off-white, granular, honeycomb block, spherical, irregular granular, powdery.

Non-toxic, odorless, slightly bitter taste.

Calcium chloride will be electrolyzed into chloride ions and calcium ions when put into water, and calcium ions can be hydrolyzed to form colloids, and colloids have adsorption effects, which can treat sewage.

Xingxiang calcium chloride has calcium chloride for the production of special treatment of sewage, which is calcium chloride with the following two characteristics.

1.Sterilization and disinfection: Chloride ions dissolved in water have the effect of sterilization and disinfection.

2.Displacement: calcium ions can replace metal cations in the effluent, especially in the wastewater treatment process containing metal cations, in order to reduce the damage of metal cations and some highly toxic substances to the biochemical section, calcium chloride is used in the pretreatment process to remove these toxic and harmful substances plays a key role, and if this substance is used in the effluent section, chloride ions play a role in sterilization, and calcium ions are removed by precipitation after generating calcium hydroxide precipitate.

Removal of silver ions and sulfuric acid heel ions.