The Selection of Efficient Antiscalant for RO Facility, Control of Its Quality and Evaluation of the Economical Efficiency of Its Application

Abstract

Adsorption of polymeric inhibitor molecules to calcium carbonate crystal surface was investigated. Inhibiting efficiencies of phosphonic acid-based antiscalants are dependent on the amount of adsorbed material on the growing crystal surface. A strong antiscalant even at a small dose provides the necessary rate of adsorption. Comparison of two phosphonic-based antiscalants was made both in laboratory and industrial conditions. A distinguishing feature of the strong antiscalant is the presence of aminotris (metylene-diphosphonic acid) ATMP. Experimental dependencies of antiscalant adsorption rates on the antiscalant dosage values were determined. Emphasis is given to the use of nanofiltration membranes that possess lower scaling propensities. Modernization is presented to reduce operational costs due to antiscalant and nanofiltration membranes. The main conclusion is that control of scaling should be implemented together with the use of nanofiltration membranes.

Keywords

• reverse osmosis
• calcium carbonate
• scaling mechanism
• phosphonic-based antiscalants
• inhibitors
• crystallization mechanism