The sludge removed from the sludge zone of the settling tank in Example 6.14 has a solids concentration of 3%. To be able to burn the sludge in an incinerator, it must be dewatered. This is to be carried out by a gravity thickener which can achieve an underflow concentration of 8%, and then the sludge will be concentrated further in a vacuum filter that will re move 75% of the water from the feed stream. The density of wet sludge is approximately equal to that of water. Calculate (a) the flowrate of thickened sludge that must be handled by the vacuum filter, and (b) the composition of the filter cake produced by the vacuum filter. Note that in example 6.14, a settling tank is used to remove suspended solids from wastewater. The rate of flow of wastewater into the tank is 10L / s, and the influent concentration of SS is 200mg/L. The removal efficiency of the settling tank for SS is (60%). The calculated amount of SS (sludge) accumulating in the sludge zone each day is 103.68 kg/day