Question (1): (18 Marks) Gaza City has a total population of 650,000 inhabitant, where 75% of the population is connected to wastewater collection system. The water consumption per capita is 100 L/day. Currently, the collected flow treated partially by aerated lagoon system. The municipality intend to change the treatment system to a completely mixed activated sludge system to be used for organic matter removal only to fulfill the Palestinian standards for reuse (Soluble BOD 30 mg/l). The given data from the municipality laboratory and assumptions: ⚫ The influent soluble Biological Oxygen demand = 500 mg/l. Biomass yield (Y) = 0.5 mg VSS/mg BOD removed • Endogenous decay rate constant (Ka) = 0.05d¹ • • The concentration of biomass (X) = 3000 mg MLVSS The concentration of recycled biomass (X) = 10000 mg MLVSS/L Growth rate (d) 2.5 1.25 100 For the completely mixed activated sludge system find the following: a) The average flow to the treatment plant. b) The mean cell residence time. c)…

Question (3): (20 Marks) You have been assigned to design a secondary wastewater treatment component based on a tricking filter technique. The flow rate is 3500 m³/day, the raw wastewater has a BOD5 of 600 mg/l. This wastewater is primarily treated with an efficiency of 35%. • Assume suitable design criteria to obtain a BOD effluent of 15 mg/l. Design the secondary clarifier • Perform all the necessary cheeks on your design.

Question (3): (20 Marks) You have been assigned to design a secondary wastewater treatment component based on a tricking filter technique. The flow rate is 3500 m³/day, the raw wastewater has a BOD5 of 600 mg/l. This wastewater is primarily treated with an efficiency of 35%. • Assume suitable design criteria to obtain a BOD effluent of 15 mg/l. Design the secondary clarifier • Perform all the necessary cheeks on your design.

Data:Total budget = $25,000BCWS = $ 8,333BCWP = $ 6,400ACWP = $ 7,800Project duration = 40 daysData date: 10 days Perform the following analyses of the project based on the data given above.a. Cost Variance b. Schedule Variance

Please explain why large initial separations on the EV S-Curve between the lines for ACWPand BCWP with BCWP above the ACWP may be an indicator of excessive front loading.

Data:Total budget = $25,000BCWS = $ 8,333BCWP = $ 6,400ACWP = $ 7,800Project duration = 40 daysData date: 10 days Plot an S-Curve and show Cost Variance and Schedule Variance on it.

Water table A L₁ = 2 m Sand y = 15.9 kN/m³ c' = 0 $' = 32° E L₂ = 3 m D Determine: a) Theoretical Depth and actual depth of penetration Sand Ysat 19.33 kN/m³ c' = 0 $' = 32° Clay c = 47 kN/m² =0

3. The following Sheet Pile is to be designed for a granular soil without the influence of the water table: Determine: L = 5m Y = 15.9kN/m³ $' = 32° Gall = 172MN/m² e) Theoretical Embedment Depth

3. The following Sheet Pile is to be designed for a granular soil without the influence of the water table: Determine: L = 5m y = 15.9kN/m³ $'=32° Gall = 172MN/m² f) Actual Embedment depth taking into account a 30% increase