Discernible are inorganic, organic, and biological fouling, incrustation and suspended matter as well as discolorations. The number of cracked and broken beads can also be counted.
We offer you the method of determining the accessibility of the pores of ion exchangers by using dye molecules.
Due to the rather large molecules the method is very sensitive and distinctly shows even minor kinetic obstructions.
You will receive microscope photos, often in conjunction with reference data (see below), and will be able to recognize fouling effects by yourself.
Cation exchanger fragments can easily be identified and photographed by cross colouring (e.g. cationic dye on anionic beads).
This loss is irreversible and can be an economic criterion for exchanging the resin.
For anion exchangers you will receive separate evaluations for the weak base and strong base portion of the mix (Quaternation level: strong base fraction in the total capacity).
For cation exchangers in conjunction with the dry mass related capacity ageing by de-crosslinking and loss of accessibility due to fouling can easily be differentiated.
Our measuring methods have the necessary precision for this (see below).
For anion exchangers we have found out correlation functions between the loss of the volume-related and the decrease of the dry mass-related capacity. This allows good conclusions on the ageing processes of the respective sample.
We have reference data for common resin types, so we can deliver interpretable results.
A bench-scale test is often helpful, as it provides essential data that is needed to determine if it is still worthwhile, or if the achieved efficiency does not justify the purification process.
This is also an indicator for the achieved cleaning efficiency. This especially applies to COD-values of anion exchangers, for which we possess a large collection of measured data.