Silica contamination

[aspearin1]

Is there a strong affinity for SiO2 (weakly negative) to bind to Primary amines? Or Quaternary amines? More specifically, on a high amine nylon membrane? We're having a slight contamination issue, but we're not quite sure if it's an issue yet.

 

[EMKWR]

Membranes are known to suffer scaling effects. This could be the deposition of carbonates but in case of high SiO2-contents, silicates will do as well. There is no real connection with the material used for the membrane, the presence of a polyvalent cation (calcium, magnesium for example) will do. Have seen a great picture recently at the UPW Europe of a membrane which has doubled in weight because of the deposition of insoluable salts.
You should try the addition of some anti-scalant.

Edwin Muller
e.f.muller@kema.nl