The performance of D301 macroporous weakly basic anion exchange resin for ion exchange reaction is its “ion exchange capacity”, which is the milligram equivalent of exchangeable ions per gram of dry resin or per milliliter of wet resin, meq/g (dry) or meq /ml (wet); when the ion is monovalent, the milligram equivalent number is the number of milligram molecules (when the divalent or multivalent ion, the former is the number of the latter multiplied by the ion value). There are also three display methods: "Total Exchange Capacity", "Working Exchange Capacity" and "Exchange Capacity".
1) The total exchange capacity represents the total amount of chemical bases per unit number (weight or volume) of the resin for ion exchange reaction.
2) The operating exchange capacity represents the ion exchange capacity of the resin under conditions, and is related to the specific operating conditions of the resin type and total exchange capacity, as well as the composition of the solution, flow rate, temperature and so on.
3) The exchange capacity indicates the exchange capacity of the resin under linear conditions, and indicates the degree of restoration of the existing chemical groups in the resin.
Generally, the exchange capacity is 50 to 90% of the total exchange capacity (generally controlled at 70 to 80%), but the operating exchange capacity is 30 to 90% of the exchange capacity (for resin), the ratio of the latter is called the resin Utilization.
In actual use, the exchange capacity of D301 macroporous weakly basic anion exchange resin contains adsorption capacity, and the proportion of the latter varies depending on the resin structure. It is not possible to perform individual calculations at this time. In the specific design, corrections are made based on empirical data, and comments are made in actual implementation.
The measurement of the exchange capacity of D301 macroporous weakly basic anion exchange resin is generally carried out under inorganic ions. These ions are very small in size and can diffuse freely into the resin and react with all the exchange groups inside. In actual use, the solution contains a lot of high-molecular organic substances, which are large in size and difficult to enter the pores of the resin, so the actual exchange capacity is lower than the value measured by the inorganic ions. This is related to the type of resin, the size of the pore structure and the substance to be processed