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)