For a long time, everyone has been very interested in the use of cation exchange resin to obtain soft water. Now a brief article on cation exchange resin is introduced. In fact, the use of ion exchange to obtain soft water is not suitable for ornamental players because of the high cost and large area. , It is not recommended for everyone to use, but it is quite convenient for the breeding farm, and you can get a lot of soft water. There are also many misunderstandings here. There are aquarists who buy and use them but they do not use it. One is a misunderstanding in the transformation, and the other is to use Quantitative misunderstandings, ions will soon be saturated with a small amount of use, and sinking is even more undesirable. In use, due to the lack of knowledge about ion exchange, the ions can be scrapped and cannot be used again. So the following is to get soft water for ion exchange Let’s do a small science lecture.
1. The efficiency of the ion reaction is increased according to the number of poles. For example: under the standard flow rate, if 1 liter of ions can process 50 liters of water, 5 liters of ions can process 500 liters of water, 10 liters can process 5 tons of water, and 15 liters of ions It is possible to process 15 tons of water. (The above data is an example, not accurate.)
2. The state of cationic products are all sodium type. The exchanged water is alkaline (see my other post: Experiment for Mi Laosan for details) because the sodium type releases a corresponding sodium every time a calcium and magnesium ion is exchanged. In water, so the PH will rise as the hardness of the carbonate decreases.
3. It is necessary to transform when using cations to obtain soft water. It is relatively difficult to transform sodium-type cations into hydrogen-type cations. To briefly introduce, one acid, one base, one acid is transformed into hydrogen type. One base, one acid, one base and the original Sodium type. The ratio of the reaction solution is hydrochloric acid concentration: the original solution is diluted with 39% concentration to 8% concentration acid solution. The ratio of the reaction solution is lye concentration: 97% content of dry flake alkali is mixed to make 7% concentration lye. The acid solution is pressed 1.5-2.0 tons per hour are passed through the ions, and then pure water is washed to a pH of about 3.5. The lye at the same flow rate is passed through the ions, and the pH is washed to about 14. The same flow is passed through the acid solution, and finally the pure water is washed to a pH above 4.5. Yes. The reaction time for transformation is 25 minutes each time.
4. Ion regenerationHydrogen-type ions need to be regenerated after being poisoned (saturated). The 8% concentration acid solution is heated to 45 degrees and the ions are passed through 1.5-2.0 tons per hour, and finally the pure water is washed to a pH above 4.5. (5 times the amount of regenerating solution circulates through ions, this method is dynamic regeneration)
5. Ion use and protection. The solid collagen in the chlorine water will cause serious damage to the resin, which will cause the ion rack to fragment and make the ions unable to be reused through regeneration. Therefore, water pretreatment equipment, high-density cotton filtration and activity must be installed during use. Carbon, here chlorine is the most serious damage to the resin, so it must pass through a unit volume of activated carbon to produce chlorine. (Tap water flow 25 kg coconut shell carbon will do).