Backfills in integrated water treatment systems play an important role, namely, they neutralize harmful chemical and organic impurities, soften water, improve its performance, and so on.
Most used backfill are:
1. Ion exchange resin;
2. Quartz sand;
3. Activated carbon;
4. Multifunctional infills.
Any backfill column type filter for water purification requires a complete replacement of backfill every few years - the frequency is determined by a specialist separately in each case. As a rule, the water treatment system itself “reports” the need for this procedure by reducing the cleaning efficiency. The removal of iron from the water begins to fail, allowing ferrous breakthroughs, and the regeneration of the backfill gives an unsatisfactory effect. With water softeners, the same story: hardness salts freely penetrate into the engineering systems of the house, forming scale and whitish spots after the water drops dry.
Estimated service life of backfills: ion exchange resin- up to 5 years, iron-removing materials- up to 5 years, activated coconut charcoal- up to 3 years, activated birch charcoal- up to 2 years, quartz sand and multilayer filling for clarification of water, up to 3 years.
The main rule that must be followed when selecting backfill for a filtration system is the exact match between the amount of backfill and the size of the filter. This will allow you to properly configure the control unit and get the most efficient operation of the entire system.
Ion exchange resin no more than 75% of the total volume of the filter column is filled up, other fillings are loaded with a layer of no more than 1 m (otherwise they are not sufficiently loosened and washed with backwash.
Life time filter loading directly depends on the degree of contamination of the source water, water consumption, and the stability of the control automation. Typically, average load life iron remover is 3-5 years, and softener 5 - 6 years old. But most often they have to be changed at the same time, since the deironing agent that has exhausted its resource begins to partially pass unremoved impurities, which has a detrimental effect on the filter medium of the softener. And by the time the decision is ripe to change the filtering load of the iron remover, it is also time to change the softener load.
So that the work on replacing the filler does not turn out to be useless, it is recommended to analyze the source water and diagnose the operation of the control valves before carrying out the work. Quite often the cause of poor water treatment is control valve one of the filters. Also, over the long years of operation of the system, the quality of the source water could change (both for the worse and for the better) according to the rules, the analysis of the input water must be done every 6 months for domestic consumers, and more often for critical cases (important technological processes in industrial settings). It is possible that it will be necessary to change the composition of the equipment or the type of filter load, reprogram the valve electronics.
Water treatment maintenance is very important for your health. Therefore, regular maintenance of the system should be part of your stay in the house.
The average service life of backfill for water softening is about 5 years, after which it is required to replacement of the cation exchanger lost its performance.
For the longest service life of the cation exchanger, it is necessary to correctly program the control unit during the first start-up and ensure preliminary water treatment.
Required quality of water entering the sodium cation system
General hardness - up to 20 mg.eq./l
Total salt content - up to 1000 mg/l
Total iron - no more than 0.3 mg / l
Water temperature - 5-35 °C
Color - no more than 30 degrees
Oil products - no
Sulfides and hydrogen sulfide - no
Stages of replacement of the cation exchanger in sodium cationization systems
Before starting work, it is necessary to organize the water supply bypassing the softener through the bypass line. Shut off the water inlet and outlet to the softener.
For safe manual operation, put the filter control unit into regeneration mode to relieve pressure. Then switch to working mode. Then de-energize the water softening system and take up the main work.
1. Disconnected from the power supply, disconnect the control unit from the hydraulic piping and disconnect the brine line of the reagent tank.
2. Before replacement of the cation exchanger carefully unscrew the control valve.
3. Without damaging the filter housing, free it from the remnants of water and spent cation exchanger.
4. Rinse well and, if possible, disinfect the internal cavity of the housing.
5. Install the body on a permanent workplace.
6. Screw the control valve all the way down and set it in a convenient place for subsequent operation.
7. After choosing the optimal position, carefully unscrew the valve from the cylinder.
8. Insert the central distribution system with slotted cap into the inside of the housing. Rotate the slotted cap into the socket on the bottom of the cylinder.
9. The upper opening of the central distribution pipe must be closed with a plug or other device that will prevent ion exchange resin from entering the distribution system during backfilling. The only condition when backfilling the plug should not fall into the central tube, this can disable the control system.
10. Fill the balloon with a small amount of water, approximately ¼ volume. This amount will buffer the ion exchange resin being loaded.
11. Insert a funnel into the neck of the cylinder, which will provide convenience when filling the cation exchanger.
12. Pour the required amount of gravel through the funnel. After backfilling with gravel, the central distribution manifold must not be pulled out of the cylinder, as if you try to put it in place, you can damage the lower slotted cap.
13. Load the filter with the required amount of cation exchanger.
14. Carefully remove the funnel through which the new filter material was added.
15. Remove the plug or tool used to cover the hole in the top of the center distribution tube.
16. Remove any remaining dust and filter material from the housing neck and threads.
17. Push the control valve with the top slotted cap onto the central distribution pipe.
18. Screw the control box clockwise into the filter housing.
19. Connect the control unit to the central water supply and supply power to it.
20. Connect the reagent brine line to the control box.
21. After completion of all work, it is necessary to supply water to the installation and release the remaining air from the filter housing.
22. Check the automatic control settings and carry out the primary regeneration to wash the cation exchanger.
Ion exchange resins are high molecular weight insoluble compounds that can show a reaction when interacting with the ions of a solution. They have a three-dimensional gel or macroporous structure. They are also called ionites.
Varieties
These resins are cation exchange (divided into strong acid and weak acid), anion exchange (strong base, weak base, intermediate and mixed base) and bipolar. Strongly acidic compounds are cation exchangers that can exchange cations regardless of A, but weakly acidic compounds can function at a value of at least seven. Strongly basic anion exchangers have the property of exchanging anions in solutions at any pH. This, in turn, is lacking in weakly basic anion exchangers. In this situation, the pH should be 1-6. In other words, resins can exchange ions in water, absorb some, and in return give away those that were previously stored. And since it is H 2 O that is a multicomponent structure, you need to correctly prepare it, choose a chemical reaction.
Properties
Ion exchange resins are polyelectrolytes. They don't dissolve. A multiply charged ion is immobile because it has a large molecular weight. It forms the basis of the ion exchanger, is associated with small mobile elements that have the opposite sign, and, in turn, can exchange them in solution.
Production
If a polymer that does not have the properties of an ion exchanger is treated chemically, then changes will occur - the regeneration of the ion exchange resin. This is quite an important process. With the help of polymer-analogous transformations, as well as polycondensation and polymerization, ion exchangers are obtained. There is salt and mixed-salt forms. The first implies sodium and chloride, and the second - sodium-hydrogen, hydroxyl-chloride species. Under such conditions, ion exchangers are produced. Moreover, in the process they are converted into a working form, namely hydrogen, hydroxyl, etc. Such materials are used in various fields of activity, for example, in medicine and pharmaceuticals, in the food industry, at nuclear power plants for condensate treatment. An ion exchange resin for a mixed bed filter can also be used.
Application
An ion exchange resin is used for In addition, the compound can also desalt the liquid. In this regard, ion-exchange resins are often used in thermal power engineering. In hydrometallurgy they are used for non-ferrous and rare metals, in the chemical industry they are purified and various elements are separated. Ionites can also purify wastewater bodies, and for organic synthesis they are a whole catalyst. Thus, ion exchange resins can be used in various industries.
Industrial cleaning
Scale can appear on heat transfer surfaces, and if it reaches only 1 mm, then fuel consumption will increase by 10%. It's still a big loss. Moreover, the equipment wears out faster. To prevent this, you need to properly organize water treatment. For this, an ion exchange resin filter is used. It is by cleaning the liquid that you can get rid of scale. There are different methods, but with increasing temperature, their options become less.
H2O processing
There are several ways to purify water. You can use magnetic and you can retouch it with complexones, complexonates, IOMS-1. But a more popular option is filtration using ion exchange. This will cause the composition of the water elements to change. When this method is used, the H 2 O is almost completely desalinated and the contamination disappears. It should be noted that such purification is quite difficult to achieve in other ways. Water treatment using ion exchange resins is very popular not only in Russia, but also in other countries. Such cleaning has many advantages and is much more effective than other methods. Those elements that are removed will never remain sediment at the bottom, and reagents do not need to be dosed constantly. It is very easy to make this procedure - the design of the filters is of the same type. If desired, you can use automation. After cleaning, the properties will be preserved at any temperature fluctuations.
Purolite A520E ion exchange resin. Description
To absorb nitrate ions in water, a macroporous resin was created. It is used to purify H 2 O in various environments. Purolite A520E ion-exchange resin appeared especially for this purpose. It helps to get rid of nitrates even with a large amount of sulfates. This means that, in comparison with other ion exchangers, this resin is the most effective and has the best characteristics.
Working capacity
Purolite A520E has a high selectivity. This helps, regardless of the amount of sulfates, to remove nitrates efficiently. Other ion exchange resins cannot boast of such functions. This is due to the fact that with the content of sulfates in H 2 O, the exchange of elements decreases. But due to the selectivity of the Purolite A520E, this reduction does not really matter. Although the compound has a low, compared with others, complete exchange, the liquid in large quantities is cleaned quite well. At the same time, if there are few sulfates, then various anion exchangers, both gel and macroporous, will be able to cope with water treatment and the elimination of nitrates.
Preparatory operations
In order for Purolite A520E resin to perform at 100%, it must be properly prepared to perform the function of cleaning and preparing H 2 O for the food industry. It should be noted that before starting work, the used compound is treated with a 6% NaCl solution. In this case, twice the volume is used compared to the amount of the resin itself. After that, the connection is washed with food water (the amount of H 2 O should be 4 times more). Only after such processing can it be taken for cleaning.
Conclusion
Due to the properties possessed by ion exchange resins, they can be used in the food industry not only for water purification, but also for processing food, various drinks and other things. Anion exchangers look like small balls. It is to them that calcium and magnesium ions stick, and they, in turn, give sodium ions into the water. During the washing process, the granules release these adhering elements. Be aware that pressure may drop in the ion exchange resin. This will affect its beneficial properties. Certain changes are influenced by external factors: temperature, column height and particle size, and their velocity. Therefore, during processing, an optimal state of the environment should be maintained. Anion exchangers are often used in water purification for an aquarium - they contribute to the formation of good conditions for the life of fish and plants. So, ion exchange resins are needed in various industries, even at home, as they can qualitatively purify water for its further use.
Poor performance of the cation exchanger depends mainly on two reasons:
- insufficient height of the layer of sulfonated coal in the filter. In this case, it is necessary to add sulfonated coal to the maximum, raise the upper drainage device as high as possible or increase the height of the filter by welding a cylindrical shell to the upper part;
- high hydraulic resistance of the pipes of the drainage device supplying water. To eliminate this phenomenon, it is necessary to unload the filter, dismantle the drainage device, remake it, increasing the number of branches and, accordingly, the number of nipples and caps. If there are no caps, it is necessary to mill more slots on the side branches. If this does not help and does not give a noticeable effect, then it is necessary to replace all pipes, increasing their diameter.
Reducing the exchange working capacity of the cation exchanger depends on several reasons:
- low quality salt used for regeneration. Salt used for regeneration must be analyzed. To do this, prepare a 10% solution of it and determine the general hardness in the usual way. It must not exceed 40 meq / l;
- damage to the drainage device in the filter, for example, when caps are torn off, when nipples are corroded, etc. In this case, it is necessary to unload the filter, inspect and repair the drainage device;
- inaccurate observance of the regeneration mode (low intensity of loosening of the cation exchanger, increased rate of passage of the salt solution, non-observance of the sequence when opening the taps, insufficient amount of salt loaded into the salt solvent). In these cases, it is necessary to bring the regeneration mode in full compliance with the filter maintenance instructions.
Intensive loss of cation exchanger during loosening accompanied by turbidity of the water. First of all, it is necessary to check the mode of loosening, avoiding the release of sulfonated coal into the washing water. This phenomenon can also occur when the quality of sulfo coal is insufficient. If the rules for storing sulfonated coal are not followed, it deteriorates, it crumbles, changing its granulometric composition. The best sulfonated coals are stored in water. In addition, the elevated air content in the water and its accumulation in the filter also contributes to the oxidation of coal.
Flat depletion curve of the cationite and its large "tail" exchange capacity.
This phenomenon is observed if the rate of water filtration in different places of the filter section is not the same, which occurs with different resistance to the passage of water at different points of the drainage device.
In this case, it is recommended to stop the filter, open the top hatch, remove the top contaminated layer, and shovel the cation exchanger layer to a depth of 1m. During the next overhaul, special attention should be paid to the hydrodynamics of the lower drainage device.
Increased salt washout period after regeneration.
The reason for this is usually increased dead space between the surface of the grout and the level of the caps. To eliminate this phenomenon, it is necessary to additionally fill, bringing it to the lower edges of the caps.
Ingress of cationite grains into softened water.
This indicates a malfunction in the drainage device as a result of the failure of the drainage caps. In this case, the filter is stopped, the drainage device is unloaded and repaired.
