**Reverse Osmosis Chemistry — Basics, Barriers and Breakthroughs**

Robert Y. Ning

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/60208

#### **Abstract**

While reverse osmosis (RO) for desalination of brackish water, seawater and waste‐ water is a most economical and powerful method, its sensitivity to fouling points to the importance of understanding the water chemistry involved and methods of fouling control and system maintenance. As a chemical developer of antiscalants, antifoulants, and operation and maintenance chemicals needed for RO systems, we present here a basic understanding of RO chemistry, the challenges of scaling and colloidal fouling that limits % recovery of permeate and some breakthroughs we have attained.

**Keywords:** Reverse osmosis chemistry, scaling, colloidal fouling, antiscalant, antifou‐ lant, tandem RO system

### **1. Introduction**

The rapidly increasing introduction of reverse osmosis (RO) membrane plants around the world for treatment of water challenges the process of training professionals and technicians needed to design, operate and maintain such systems. The systems vary in size from 100 million gallons per day (15,800 m3/hour) municipal systems for municipal wastewater, brackish water and seawater desalination, down to 10 gallons per minute (38 liters per minute) used in kidney dialysis clinics. The sensitivities of RO membranes toward fouling and challenges in sustaining operation highlight the need for understanding the chemistry that impacts on the design, performance and maintenance of RO systems. In this chapter, the basics, barriers and breakthroughs in RO chemistry are briefly reviewed.

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