Method for removing Ca, Mg ions in water

This is the process of water softening.

Chemical precipitation or ion exchange resin adsorption (cationic resin).

Adsorption with cationic resin is simple and can be done by passing water through the resin sufficiently. After that, pay attention to adjusting the pH.

Chemical precipitation (equations and reference flowcharts are in my blog) process.

Equation: Calcium ions and magnesium ions react with bicarbonate together with caustic soda to produce water-insoluble calcium carbonate precipitates and magnesium hydroxide precipitates. In the pH range, the softening effect on calcium ions is the best, and at a pH of 11, the softening effect on magnesium ions is the best. As a result, excess caustic soda is specially added to increase the pH in the subsequent process.

It's so simple to boil how to be so troublesome.

Because the Ca and Mg ions in the water will precipitate when boiling, they are calcium carbonate and magnesium hydroxide, both of which are white.

Add a solution with carbonate ions or can reflect the carbonate ions that produce calcium and magnesium ions to precipitate out.

It can be removed with lime, soda ash.

or remove with an ion exchanger.

Take advantage of the fact that the carbonates of calcium and magnesium are insoluble in water!

When air is blown into the water, CO2 reacts with Ca and Mg ions to form a precipitate.

It belongs to the problem of hard water softening: there are many ways, you can find it directly!

Mainly: boiling method, lime soda ash method, anion and cation exchange method and so on!

Add EDTA to remove calcium and magnesium, add barium chloride to remove sulfate ions, and you can't add water if you want to drink.

There is a special water softener, and after softening treatment, the concentration of calcium and magnesium ions will drop a lot.

The removal of calcium ions allows the passage of Na2CO3 because Ca(2+)+CO3(2-)==CaCO3 (precipitate).

The removal of magnesium ions allows NaOH to be introduced because mg(2+)+2oh(-)==mg(OH)2(precipitate).

。Micelle-enhanced ultrafiltration technology can effectively remove metal ions from water. When an anionic surfactant is added to heavy metal ion wastewater, when its concentration is greater than the critical micelle concentration, a large number of amphiphilic aggregates will be formed, which are called micelles.

Metal cations are then attracted to the negatively charged micelles and adsorbed on the surface of the micelles. The solution is then passed through an ultrafiltration membrane with a pore size small enough to retain micelles, and the adsorbed metal cations are retained. Untrapped ions and surfactant monomers pass through the ultrafiltration membrane to the permeate side.

As a result, the permeate contains only very low concentrations of surfactants and metal ions.

Nanomicron carbon material adsorption to remove heavy metal ions in water:

There is a linear relationship between the number of functional groups dissociated at different pH values between Qm and K F pairs at different pH. The adsorption capacity of the two carbon nanotubes after oxidation was higher than that of activated carbon after unit specific surface area. The adsorption behavior of Fe( ) and Fe( ) ions in carbon nanotubes prepared by chemical vapor deposition method was studied, and it was found that the pH value had a greater effect on the adsorption of Fe( ) ions on carbon nanotubes than Fe( ).

At the same equilibrium concentration, the adsorption capacity of carbon tubes for Fe( ) ions was higher than that of Fe( ) kinetics, and the adsorption of the two adsorbents on carbon nanotubes could be described by a quasi-secondary adsorption kinetic model. Thermodynamic studies have shown that the adsorption of Fe( ) and Fe( ) ions on carbon oxide nanotubes is a spontaneous, endothermic and entropy increasing process.

The adsorption of nickel, copper, zinc and cadmium ions on the surface of carbon nanotubes in the multi-component system was studied, and it was found that for the one-component and two-component systems, the adsorption amount followed the following order: Cu (2+)Ni (2+)Cd (2+)Zn (2+). This is consistent with the order of ionic oxidation capacity based on standard electrode potentials. For the two-component, three-component and four-component systems, the Langmuir model can describe the adsorption behavior of the adsorbent on Cu (2+) ions well, while for the other three ions, the adsorption capacity is maximum.

In the three- and four-component groups, except for the Cu (2+) ion, the adsorption order of the other three ions is as follows: Cd (2+) Zn (2+) Ni (2+). The competitive adsorption of multi-component systems is closely related to the redox characteristics and ion exchange of ions.

Hello lz: Polyaluminum chloride and lime are mainly used to fix cadmium ions.

Chemical formula CDM (M stands for anion) + Ca(OH)2 = CD(OH)2 + CAM

At the same time, lime changes acidity and alkalinity to promote the fixation of cadmium in aluminum chloride The specific equation does not. It's just that AlCl3 produces Al(OH)3 and CD reaction precipitates under alkaline conditions.

Most of the impurities in tap water are Ca, Mg, Cl and other ions, which can be precipitated by ion exchange to achieve the purpose of removing impurities.

Flocculants are generally added, such as alum, iron salts, aluminum salts, ferrate, etc.

These salts can be hydrolyzed in water to form colloids, and the colloidal particles have a large specific surface area, which can adsorb small suspended particles in water, so as to achieve the purpose of water purification. However, this only removes some insoluble smile particles in the water, but does not remove ions in the water.

At present, the main methods for removing ions in water are electrodialysis, reverse osmosis, and ion exchanger.

Hello, if you want to remove iron ions and some other impurities from water on a large scale. Some purification equipment is required.

Generally, the methods used to purify water include distillation, reverse osmosis, electrolysis osmosis, etc. Through these methods, heavy metals, microorganisms, organic salts and trace elements in the water are removed together, so that the water quality reaches a certain purity and its resistivity value increases.

At present, there are many reverse osmosis methods in factories. The main thing is relative economy and stability. The quality and flow of the transformable water are better.

If you are only on a small scale, you can only take physical methods such as installing filtration devices and carrying out some effective sedimentation. Filtration materials generally include: activated carbon, asbestos, etc.

Happy to you.

Industrial Circulating Water? Use a manganese sand filter on the circulating pipeline Those who have done industrial water treatment should know: the manganese sand iron removal filter not only plays the role of catalytic iron removal, but also plays the role of mechanical filtration to prevent the corrosion products and materials of the return water system from entering the boiler feed water.

The continuous operation cycle is long, the self-consumption water consumption is small, the operating cost is low, and the annual manganese sand is supplemented by 3%. Total iron for effluent.

The low-valent iron ions and low-valent manganese ions in the water are oxidized by oxidation method into ** iron ions and ** manganese ions, and then removed by absorption and filtration to achieve the goal of reducing the iron and manganese content in the water. In fact, it is a large iron can, which is filled with manganese sand, and when the water flows over, the iron ions are intercepted, and can be recycled through water reduction.

There are many manganese sand filter manufacturers' web pages on the Internet. It is more practical for circulating water treatment. In addition, aeration and iron removal also have a large application.

In addition: the development of industrial circulating water iron removal is relatively perfect, so there is no need to worry.

Is it iron or ferroic? If it is iron ions plus soda ash precipitation, filter it. If you're not sure, ask your chemistry teacher at a nearby school.

Using soda and baking soda may not work. If the iron ions are large, you can use a strong alkali (such as caustic soda) to precipitate it, filter it out, and then neutralize it with an acid (such as hydrochloric acid) to adjust the pH value to about 7. (It seems to be a bit more costly).

If it is just circulating cooling, it should not be affected, as long as the conductivity is controlled within the normal range, so that a uniform protective film is formed inside. It's that complicated. The water quality is the responsibility of the pharmaceutical company.

Yes, be careful about the quality of drinking water Now there are better water filtration devices, from 300 to 5000 yuan, which can meet your requirements Supermarkets and specialty stores have You have to pay attention to the brand

Iron ions are positive 3valent and harmful to the human body. But positive 2-valent ferrous ions are beneficial to the human body. Iron deficiency anemia is a deficiency of ferrous ions.

Since it is industrial water. It can precipitate iron ions with other chemicals such as sodium hydroxide. Then filter it.

Hopefully, you guys will find the right way to filter.

It is first made into distilled water, and then deionized water is made from ion exchange resin, that is, pure water.

It is possible to purchase equipment for small boiling of distilled water, and then purchase ion exchange resin appropriately (carefully according to the operating procedures).

Heat and then filter.

The principle of utilization is the hydrolysis of iron ions to generate iron hydroxide precipitates. Heating facilitates this reaction to proceed more thoroughly.

At the same time, iron hydroxide precipitation also has the function of removing impurities.

After ozonation, filtration can completely remove what we have done for the tofu factory, and the iron content of the tofu processing water is high, and the tofu can not be ordered.

Chlorine dioxide can be used to remove iron and manganese. In drinking and industrial water, dissolved metallic iron and manganese can cause coloration and precipitation. Under alkaline conditions, chlorine dioxide rapidly oxidizes these metal ions to form insoluble compounds.

Oxidation of dissolved manganese ions, requiring multiples (by weight) of chlorine dioxide; The oxidation of dissolved metal iron ions requires multiples (by weight) of chlorine dioxide. In contrast, chlorine takes several days to oxidize manganese dissolved in water, and it does not oxidize iron dissolved in water that is chelated by organic matter.

Fainting, occasional iron deficiency anemia. Our tap water is purer than pure water.

In fact, it is very simple, iron ions are generally combined into compounds.

Then add a filter in front of the faucet.

You can use a new mask, but then the flow of water is smaller, and there is another way.

It also works well to get some clean sand filtration

RO reverse osmosis is used, but it is expensive.

Add a weakly alkaline liquid to precipitate.

Put a large magnet in the cup.

Add alum and take a small amount to try.

I'm not sure.

Add sodium bicarbonate.

Don't know if it's okay? With experience.

It's very simple, replace the reaction with a silver mirror, and so on.