An Overview of Fouling Mechanisms, Prediction and Mitigation Strategies for Thermal Desalination Plants

Despite technological advances of several desalination processes such as reverse osmosis, still considerable proportion of installed units are thermally driven processes which their efficiency can severely be reduced by the formation of fouling deposits on heat transfer surfaces. For many years, it has been practical strategy to avoid fouling rather than facing it. Some of these strategies are operating units at relatively low temperatures to prevent the supersaturation of saline waters, over-design of heat exchangers or over-dosage of antiscalants. Nonetheless such practices are now under scrutiny due to new environmental regulations and high costs of fuels and operation. This paper endeavours to address some of these concerns by highlighting governing fouling mechanisms and introduce some revolutionary prediction methods as well as new online mitigation methods and surface treatment based on ion implantation or sputtering techniques.