Question 4: [20 marks The gravity solids-flux curve for a certain treatment system is shown in Figure Q4. For this system, the design mixed liquor flow to the secondary clarifier is 2500 GPM, the mixed liquor suspended solids (MLSS) is 3000 mg/L and the underflow concentration is 11,000 mg/L. Determine; 1) The thickening area (m), [10 marks) ii) The values of the batch settling and underflow pumping components of the solids flux, SF, and SF. (kg/(m.hr)) and [4 marks] iii) The percent recycle rate (Q./9). [6 marks) 11 10 9 8 lt 6 Solids Flux, kg/m'.hr 5 4 3 2 1 0 1 2 3 9 10 11 12 13 14 4 5 6 7 8 Concentration, kg/m Figure 04: Gravity solids-flux curve