Successful Antiscalant Field Trial: Optimization at Higher pH and Seawater Temperature

Abstract

Seawater desalination is a multibillion dollar business in Europe and is estimated to double its worldwide capacity every 5 years. As the number and scale of plants increase, operational and maintenance costs are decreasing, with seawater desalinated prices currently below 0.50/m³. Cost reductions are related to improved energy recovery systems, more efficient plant operation and systems, advancements in membrane performance (particularly boron removal), and better pretreatment and posttreatment processes. In addition, a more effective operation requires plant personnel to operate a desalination plant closer to its contractual criteria to save energy and resources. For example, as seawater temperatures increase from 16°C to nearly 30°C in the summer, the Larnaca Desalination Plant, Cyprus, operates first- and second-stage reverse osmosis at higher pH to improve boron removal, which necessitated having a well-performing, cost-effective antiscalant. The cost and volume of chemicals required plant personnel to choose an appropriate antiscalant and optimize its dosing.