Reverse osmosis is the contemporary alternative for shipboard production of drinking water.

(a) Describe using simple diagrams where necessary, the principle of

(i) Osmosis (3)

(ii) Reverse osmosis (3)

(b) (i) Sketch a line diagram showing a 'single pass system' for producing fresh water from seawater. (4)

(ii) Describe such a system. (4)

(iii) State the safety features that may be incorporated into the plant. (2)