Are macroporous resins ion exchange, or adsorption, in water treatment?

Macroporous resin is a pore with physical properties, the pores can be through organic macromolecular substances, relying on intermolecular van der Waals force can adsorb organic macromolecular substances, with adsorption effect, but when used as water treatment, because there are no organic macromolecules in the water, or a small amount, but it contains a large amount of electrolytes (that is, salts), ionization is followed by anions and cations, and macroporous resin also has a lot of ion exchange groups, at this time it can exchange ions in the water to achieve the purpose of purifying water, In other words, macroporous resin has adsorption and ion exchange, but it mainly plays an ion exchange role when used for water treatment.

Macroporous resin, also known as fully porous resin, polymer adsorbent, is a kind of polymer characterized by adsorption, which has a concentration and separation effect on organic matter. It is a good adsorbent in itself, so it is adsorption.

It has an adsorption effect, and through the selection of solvents and solutions, it plays an ion exchange role.

Macroporous adsorption resin selectively adsorbs organic substances from solution through physical adsorption, so as to achieve the purpose of separation and purification. Its physical and chemical properties are stable, insoluble in acids, alkalis and organic solvents, good selectivity for organic matter, not affected by the presence of inorganic salts and strong ions and low molecular compounds, and can adsorb solvents and expand in water and organic solvents. Take a closer look at its introduction:

Ion exchange resin.

Ion exchange resins are insoluble polymer compounds with functional groups (active groups that exchange ions) and a network structure. It is usually spherical particles. The full name of an ion exchange resin consists of a taxonomic name, a skeleton (or gene) name, and a basic name.

The pore structure is divided into two types: gel type and macroporous type, and all resins with physical pore structure are called macroporous resins, and "macropores" are added before the full name. If the classification is acidic, "yang" should be added before the name, and if the classification is alkaline, "yin" should be added before the name. Such as:

Macroporous strong acid styrene-based cation exchange resin.

Adsorption resin. Adsorption resin refers to a class of polymers, which can be used to remove organic matter in wastewater, decolorize sugar solutions, separate and refine natural products and biochemicals, etc. There are many varieties of adsorption resins, and the changes in monomers and functional groups on monomers can endow resins with various special properties. In fact, adsorption resin refers to a class of polymer polymers, the appearance of which is generally a small round ball with a diameter of mm, which is a new porous resin developed in the field of polymers in recent years, and is often used for wastewater treatment, chemical separation and purification.

Ion exchange resin is mainly based on the functional groups on the functional groups (such as H+, OH- ions) and the anions and cations in the feed solution to replace the reaction, so as to achieve the purpose of purification or purification and separation;

Macroporous adsorbents are mainly based on the adsorption of specific surface area and the interception of pore volume and pore size to complete the purpose of adsorption, separation and purification, of course, some macroporous adsorbents also have the function of ion exchange.

At present, the domestic ion exchange resin industry is extremely chaotic, cutting corners, especially some environmental protection engineering companies for their own interests, stealing beams and columns, some domestic processing of foreign brands, some domestic well-known brands of counterfeit and shoddy products, and end users, perhaps because of the greed for cheap, but more because of the policy impact of bidding and bidding at a low price, so that low-cost procurement, high-cost maintenance and operation. Most of the domestic market is like this - numb ...... in helplessness

The older generation of technicians have reached retirement age, and the new generation of technicians, you can say that what you learn in school is useless, or you can say that all this is caused by policy, but let me ask, are you really in this position, for the responsibility of that generation? Wake up, if this continues, and the country will introduce major policies, what else can we do? And what can change?

Go for it! Water can carry a boat, but it can also capsize a boat!

The function is to adsorb various anions and cations in the water to achieve the purpose of purification.

Ion exchange resins do not have capillaries inside when dry. It swells when absorbing water, forms very fine pores between the macromolecular links, and produces molecular adsorption through the van der Waals attraction between molecules.

Ion exchange resins can adsorb various non-ionic substances like activated carbon and expand its functions. Some macroporous resins without exchange groups are also capable of adsorbing and separating a variety of substances, such as phenols in chemical plant wastewater.

Hello dear, one is the polymer skeleton of the network structure. The second is the functional group attached to the backbone, and the third is the exchangeable ion with the opposite charge to the functional baseband. The three are interdependent, and the repentant limbs are unified in each ion-exchanged bead.

As a commodity, exchange resin often contains a certain amount of water during transportation, storage and use, so water molecules are filled between the skeleton, functional groups and counterions of each ion exchange resin. Gel-type ion exchange resin can be prepared by conventional suspension polymerization method, the product is generally transparent and non-porous, and micropores are generated in the resin phase after the resin absorbs water. Macroporous ion exchange resin can be prepared by pore making technology, which is different from gel resin, whether the macroporous resin is in dry or wet state, shrinkage or swelling, there are more and larger pores than gel resin, and the surface is larger, which is conducive to the migration and diffusion of ions, and improves the exchange rate and work efficiency Compared with the exchange resin from Zheng Luzi, there are no functional groups and counterions of functional groups in the composition of adsorption resin, which is similar to macroporous resin without functional groups and functional group counterions. In the manufacturing process, more crosslinkers are often used and more stringent pore-forming agents are used to synthesize adsorbent resins with different pore sizes, different pore volumes and different specific surface areas with a larger specific surface volume, hoping to help you.

Hello Kiss is happy to answer this question for you. Similarities and differences between the principle of ion exchange resin regeneration and adsorbent regeneration: ion exchange resin refers to a polymer compound with an ion exchange group, which has a new function that general polymers do not have-ion exchange function, which is essentially a reactive polymer.

It is a kind of three-dimensional network polymer material with ionizable groups, its shape is generally granular, insoluble in water and general acids, alkalis, and insoluble in ordinary organic solvents, such as ethanol, acetone and hydrocarbon solvents, the particle size of common ion exchange resins is, and the particle size of some other uses of ion exchange resins may be greater or smaller than this range. 1. From the perspective of pore structure, the specific surface area of macroporous ion exchange resin is low, and the pore structure of adsorption resin is developed and the specific surface area is high. Adsorption resin refers to a class of resin with adsorption function, which is a new type of resin developed on the basis of ion exchange resin Crude resin, which refers to a class of porous, highly cross-linked high-fraction copolymers, also known as polymer adsorbents, with a large specific surface area and appropriate pore size, which can adsorb some substances from the gas phase or solution 2, from the perspective of application principle, adsorption resin is mainly through the pores inside the resin for physical adsorption, and the high specific surface area provides high adsorption capacity; Macroporous ion exchange resins mainly allow exchangeable ions on the resin to exchange with ions in solution, and macropores only make the solution and solute easily permeable into the resin (compared to gel resins).

However, according to this theory, the macroporous ion exchange resin also has the function of adsorbing organic matter, but the adsorption amount is low and has no application value. 3. From the perspective of skeleton structure, there is no difference between macroporous ion exchange resin and adsorption resin, but some adsorption resins do not have functional groups, so their synthesis methods are similar. Adsorption resins with highly polar functional groups are difficult to distinguish from macroporous ion exchange resins.

Dear Kiss I'm glad to answer for you, my answer is as follows: the adsorption resin cluster vertical and ion exchange resin skeleton can be the same, for example, the world can be styrene, acrylic, etc., the difference is that the adsorption resin is generally larger than the surface area, through hydrophobic action, etc., there is no substance released into the environment when it adsorbs the target; The specific surface area of ion exchange resins varies from more than a dozen to several hundred, but there are strong polar functional groups that adsorb ionic substances, and there will be equally charged ions that are exchanged into the solution.

Water treatment resin is divided into cationic resin and anionic resin, cationic resin is subdivided into sodium type and hydrogen type, in the aqueous solution can dissociate some cations (such as H+ or Na+), sodium resin will exchange calcium and magnesium ions in the water into sodium ions, so that the water becomes soft; Hydrogen resin is to exchange calcium and magnesium ions in water into hydrogen ions to soften water, anionic resin contains replaceable hydroxide ions, and anions (such as OH or Cl) can be dissociated in aqueous solution, which can be exchanged with acid ions in water. That is, the ions in the resin are exchanged with the ions in the solution, so that the ions in the solution are separated. Using both anionic resins and hydrogen-based cationic resins can turn water into pure water.

Ion exchange resins are in high demand in the water treatment field, accounting for about 90% of the production of ion exchange resins, which are used for the removal of various anions and cations in water.

Ion exchange resins are divided into anionic resins and cationic resins, which can be mixed to remove all anions and cations in the water, leaving only water molecules.

It can remove many ions from water, but not molecules.

Adsorption exchange principle of ion exchange resin:The ions of the resin itself are generally low-valence ions, so when the resin is in contact with water, according to the adsorption selectivity of the resin, the ** ions in the water will be adsorbed, and the low-valence ions will be released, and these released low-valence ions will be combined with other ions in the water to become harmless substances, and in the actual use process, the resin is often converted into other ionic forms for use, such as the general cation exchange resin will be converted into sodium resin and then used, so as to achieve the purpose of softening water.

Adsorption sequence of ion exchange resins:1. Adsorption sequence of cations by ion exchange resins:

fe3+ >al3+ >pb2+ >ca2+ >mg2+ >k+ >na+ >h+

2. The adsorption sequence of anions by strong alkaline anion exchange resin:

SO42 >NO3 >Cl >HCO3 >OH3, Weak Alkaline Anion Exchange Resin Adsorption Sequence of Anions:

OH > citrate3> SO42> tartrate2>oxalate2>PO43 >NO2>Cl> acetate >HCO3

What is selectivity in ion exchange resins?

The selectivity of ion exchange resin refers to the metal ions that can be adsorbed by ion exchange resin, there are many metal ions in sewage, and ion resin can not absorb all metal ions cleanly, some metal ion resins have relatively weak adsorption capacity to it and some are relatively strong, that is to say, ion exchange resins can only adsorb some metal ions in a targeted manner, which is the selectivity of ion exchange resins.

Selectivity of ion exchange resins:

Experiments have proved that the adsorption capacity of ion exchange resins for different ions at low concentration and room temperature has the following rules.

The adsorption order of metal ions by cation exchange resins is:

fe3+>al3+>pb2+>ca2+>mg2+>k+>na+>h+。

The adsorption sequence of anions by strong alkaline anionic resins is:

so42->no3->ci->hco3->oh-。

The order of adsorption of anions by weakly basic anionic resins is:

OH-> citrate 3->SO42-> tartrate 2-> oxalate 2->PO43->NO2->Cl->acetate-

hco3-。

Ion exchange resins have different affinities for different ions in solution and are selective for their adsorption. There is a general rule about the strength of the adsorption of various ions by resin exchange, but different resins may be slightly different. The main rules are as follows:

Ions are usually preferentially adsorbed, while valence ions are weakly adsorbed. Among the same ions of the same valence, the larger diameter of the ion is more strongly adsorbed. The order in which some cations are adsorbed is as follows:

The general order of adsorption of inorganic acids by Fe3+ >Al3+ >PB2+ >Ca2+ >Mg2+ >K+ >Na+ >H+ strong basic anionic resin is as follows

so42－> no3－ >cl－ >hco3－ >oh－

The general sequence of the adsorption of anions by weakly basic anionic resins is as follows:

OH > Citrate 3 > SO42 > Tartrate 2 > Oxalate 2 >PO43 > NO2 >Cl > Acetate >HCO3 The decolorization of sugar solution often uses strong alkaline anionic resin, which has strong adsorption of melanoid (the reaction product of reducing sugar and amino acids) and the alkaline decomposition products of reducing sugar, but weak adsorption of caramel pigment. This is thought to be due to the fact that the first two are usually negatively charged, while caramel has a weak charge.

In general, resins with a high degree of crosslinking have strong selectivity for ions, and resins with macroporous structures have less selectivity than gel-based resins. This selectivity is greater in dilute solutions and less in concentrated solutions.