Dissolved Oxygen

Dissolved oxygen is a measure of the degree of pollution in water. Tap water has the highest level of DO while grease trap has the lowest level. Tap water has the highest level because there is a low amount of micro-organisms in the water, hence not much of oxygen is taken up. Grease trap has low level of DO because there is more organic waste in the water and that the bacteria needs to consume oxygen to survive, thus level of dissolved oxygen in grease trap is low.