What is the principle of exchange of sodium ion resin?
When the sodium ion exchange resin fails, the regeneration process is carried out to restore its exchange capacity. Regeneration agent for cheap goods (the salt solution can be adapted to local conditions, local materials, such as water or waste liquid can also be NaNO3), following the regeneration process of reaction:R2Ca+2NaCl==2RNa+CaCl2R2Mg+2NaCl==2RNa+MgCl2By the above treatment, the resin can restore the original exchange performance.
The sodium ion exchange softening treatment is characterized by:(1) to remove the hardness of water, and basicity unchanged, but only Ca2+, Mg2+ and Na+ equal charge molar exchange;(2) the content of Mg2+ in natural water are generally relatively small, mainly exchanged is Ca2+ and Na+, and the molar mass of calcium M (Ca) is 20 M, the molar mass of sodium (Na) is 23, close to, therefore, sodium ion exchange softening water salinity is basically unchanged the water dissolved solids, not much changes;(3) in the regeneration process, sometimes due to wash thoroughly, or leakage of regeneration agent valve system, the water chlorine after softening treatment rather than raw water has increased, but by careful operation can be avoided.
The sodium ion exchange principle is the atomic softening treatment by sodium cation exchange resin, so that the water hardness components Ca2+, Mg2+ and Na+ in resin exchange, and adsorption of Ca2+, Mg2+, the water softening. For example, "RNa" stands for sodium type resin and its exchange process is as follows:2RNa+ Ca2+==R2Ca+2Na+2RNa+ Mg2+==R2 Mg+2Na+That is, the water passes through the sodium ion exchanger, and the Ca2+ and Mg2+ in the water are replaced by Na+. After a primary Na+ exchange, the residual hardness of water is generally less than 1.5 * 10-2mmol/L, which can be used for low pressure boilers.
