Details

Autor(en) / Beteiligte

• Van der Leeden, M.C.
• Van Rosmalen, G.M.

Titel

Aspects of additives in precipitation processes: Performance of polycarboxylates in gypsum growth prevention

Ist Teil von

• Desalination, 1987, Vol.66, p.185-200

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

1987

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• A compendious survey of various types of additives in relation to their application is presented. Also some new measuring techniques to determine precipitation kinetics, agglomeration and other crystal features, which are subjected to additive adsorption, are briefly discussed. In the field of water treatment and desalination additives are widely used either alone as inhibitors or in combination with dispersants and corrosion inhibitors. To quantify the influence of polycarboxylate inhibitors with variations in their molecular structures on the crystallization of gypsum, suspension growth experiments were performed using the “constant composition” method. Additionally the synergistic effect of either two inhibitors or an inhibitor and a dispersant was determined. The most effective growth retarders at pH 5 appeared to be unsubstituted low-molecular weight polyacrylates. At pH 8, where the performance of polyacrylates is highly reduced owing to their far advanced ionization, introduction of itaconic acid segments into the polymer resulted into an enhanced effectiveness. The combination of polyacrylic acid and polystyrene sulfonic acid gave rise to a synergistic effect.