Chapter 10 - Reverse osmosis: Fundamental causes of membrane deposition and approaches to mitigation

Abstract

Reverse osmosis (RO) has become a common practice for industrial and municipal desalination. Developments in the technology since its commercial beginnings around 1965 have made RO the leading technology for desalination today. Current RO membranes offer higher rejection of solutes and higher permeability of water than membranes did just 10 to 15years ago. Despite advances in performance over the years, one major challenge still facing the technology is deposition of materials on the membranes. Deposits, including organic compounds, scale, bacteria, and suspended solids, affect system performance via reduced productivity and poor product water quality, ultimately leading to decreased efficiency and increased production costs. Pretreatment, equipment design, and system operations can all impact the nature and degree of deposition, as can the characteristics of the membranes themselves. This chapter discusses RO technology, the nature of deposits, factors that minimize or enhance deposition, and techniques for deposit mitigation.