title: 3-step approach towards evaluation and elimination of acid use in pre-treatment for a brackish water reverse osmosis process.
abstract: To control carbonate scale formation on reverse osmosis (RO) membrane surfaces, it is common practice to add acid as a pre-treatment chemical. However, advancements in the formulation of proprietary scale inhibitors have resulted in a re-evaluation of the need to suppress the pH of RO feedwater. In this study, a 3-step approach was taken to eliminate sulfuric acid pre-treatment at a 4.5 MGD (17,000 m(3)/day) brackish water RO plant operating for over 7 years without previous membrane replacement. The 3-Step approach adopted in this study to evaluate and eliminate use of acid in pre-treatment process involved first pilot testing the plan to reduce the dependence on acid. Secondly, implementing the plan on the full-scale system with conservative pH increments and thirdly continuously screening for scale formation potential using a "canary" monitoring device. This 3-step approach resulted in the successful elimination of sulfuric acid pre-treatment at the brackish water RO plant, with an estimated $105,000 minimum annual cost savings.
authors: University of Central Florida, Department of Civil, Environmental and Construction Engineering, Orlando, FL 32816-2450, USA. tjaya@knights.ucf.edu
authors: Jayapregasham
authors: J
authors: Tharamapalan
authors: Christopher C
authors: CC
authors: Boyd
authors: Steven J
authors: SJ
authors: Duranceau
mesh_terms: D000143:Acids / Q000737:chemistry*; D003365:Costs and Cost Analysis; D006863:Hydrogen-Ion Concentration; D009995:Osmosis; D010865:Pilot Projects; D013464:Sulfuric Acids / Q000737:chemistry
chemical_list: D000143:Acids; D013464:Sulfuric Acids; C033158:sulfuric acid