Modified pectin-based polymers as green antiscalants for calcium sulfate scale inhibition

In water processing industry, the precipitation of calcium and magnesium as carbonate, sulfate or phosphate and their adhesion to equipment surfaces is the main problem of mineral scaling. Many chemicals and antiscalants have been widely reported to mitigate the mineral scaling problems, but the efficiency is low on both economic and environmental grounds. In view of that, hydrolyzed pectin-based graft copolymers were synthesized and further functionalized by polymer analogous reactions for use as green antiscalant. The effect of functional graft copolymers on the crystal formation of calcium sulfate was investigated. From there it was observed that the ability to prevent the precipitation of calcium sulfate from homogeneous condition was almost independent of temperature and pH. The morphology and crystal structure of the precipitates were investigated using imaging and X-ray diffractometer (XRD). The result shows that the reported functional graft copolymers changed the morphology and shape of the crystal structures of CaSO4 precipitates from tubular to spherical. (C) 2012 Elsevier B.V. All rights reserved.