Determine the required volume of a completely mixed activated sludge aeration tank for a conventional activated sludge system treating a design flow rate of 34,560 m³/d, where the effluent standards are 30.0 mg/L for BOD5 and 30.0 mg/L for total suspended solids (TSS). Assume that the BOD5 of the effluent TSS is 70% of the TSS concentration. Assume the BOD5 concentration leaving the primary clarifier is 128 mg/L that the MLVSS concentration (Xa) is 2,500 mg/L. Assume the following values for the growth constants: • K = 100 mg/L BOD5 • μm = 2.5 d−1 • kd = 0.050 d 1 Y = 0.50 mg VSS/mg BOD5 removed Express your answer in m³ and round to the nearest integer.

Determine the daily volume of methane and total gas produced in an anaerobic digester if the biosolids flow rate is 200 m³/d and the COD concentration going into the reactor is 5,000 g/m³. Assume yield is 0.05 g VSS/g COD, that there is 90% COD removal, and that methane is 50% of the total gas volume. Assume that actual gas production at the operating temperature is 0.4 L of CH4 per g of COD. Express your answer in m³/d and round to the nearest integer.

Considering the following stoichiometry shown below, calculate the theoretical true yield of bacteria that use the organic molecule butyrate (C4 H7O2¯) as their source of energy. Express your answer with the units of grams of C5 H7O2 N per gram of O2 and round to the nearest 0.01. Stoichiometric relationship for the microbial oxidation of butyrate with O₂ as terminal electron acceptor 2C4H;O, +502+NHẠ* → C5 H7O2 N + 5H2O+ HCO3 + CO2 Stoichiometric relationship for the complete oxidation of butyrate C4H7O2 +502 + H+ →4CO2+4H₂O

Refer to the figure below. Given: L₁ = 4m, L2 = 8 m, l₁ = l2 = 2 m, y = 16 kN/m³, Ysat = 18.5 kN/m³, and ' = 26°. Use the charts presented below the answer fields. Sand c' = 0 Anchor L₁ Water table Sand Ysat c' 0 $' Sand c' = 0 1. Determine the theoretical depth of penetration. (Enter your answer to two significant figures.) D= m 2. Determine the anchor force per unit length. (Enter your answer to two significant figures.) F= kN/m 3. Determine the maximum moment in the sheet pile. (Enter your answer to two significant figures.) CDL₁ Mmax = 0.5 kN-m/m 0.4- -24= &' 26° 0.3 -28° 30° 32° 0.2 34° 36° 38° 0.1 0.0 0.1 0.2 0.3 0.4 0.5 1.18 1.16 1.14 1.12 1.10 1.08 1.06 1.04 4₁/(L₁+ L₂2) L₁ 4₁+12 0.3 0.2 = 0.4

For the gravity concrete dam shown in the figure, the following data are available: - Unit weight of concrete (Yeone) = 2.4 ton/m³ - Horizontal earth quake coefficient (Kh) = 0.1 Neglect( Wave pressure, silt pressure, ice force) H=0.65, (Ywater) -1 ton/m³ Find :- a- heel and toe stresses (Pain & Pmas) b- factor of safety against sliding and overturning (F.S. & F.Sover). Solve in table on paper W 8m 6m 8m 94m 0.9

A market segment consists of 500 individuals. A Logit mode choice model (with logit parameter equal to 1) has been estimated for this market resulting in the following utility function: U = ẞm 0.40C 0.037 where C is out-of-pocket cost in $ and T is travel time in min. Values of ẞm are: Bus: 0.00; Rail: 0.50; Car: 1.50. For a particular origin-destination pair, the cost of a car trip is $2 and the duration 8 minutes, a rail trip is $1.50 and takes 12 minutes, while a bus takes 20 minutes and costs $1.25. a. Predict the number of trips for each mode. b. Which one of the following policies would lead to the largest increase in bus passengers? Why? (i) An increase in the price of gas that increases the cost of a car trip to $3, while all other parameters remain constant. (ii) Introducing an express service that decreases the travel time of the rail to 10 min, while all other parameters remain constant. (iii) Decrease the cost of the bus to $1, while all other parameters remain constant.

Q1: For the gravity concrete dam shown in the figure, the following data are available: -Unit weight of concrete (Y)-2.4 ton/m Neglect Wave pressure, silt pressure, ice force and carth quake force) -0.65, (7) 1 ton/m' Find factor of safety against sliding and overturning (F.Sas & F.Ser), If heel and toe stresses (P & Pan) are 57.17ton/m² and 84.53 ton/m² respectively. Solve in table on paper w.s.i 83m 10m 8m 80m

In this question, we are going to learn about the gravity model. As discussed in class, an alternative and frequent way to model the demand is doing it in 4 steps: Generation/Attraction, Distribution, Mode choice, and Route choice. In the generation/attraction step, we estimate the number of trips that depart and arrive from each zone, in a similar way as we studied generation in the lectures. The idea of the distribution step is, taking the generation and attraction numbers as known, estimate the number of people going from each zone to each zone. Let's be precise: Consider that you know O₂ for every zone i, representing the number of users that have i as their origin. Similarly, you know Dj, representing the number of users that have j as their destination. We want to estimate Mij, i.e., the number of users going from i to j. The matrix M

= a2+ Assume an origin is connected to a destination with two routes. Assume the travel time of each route has a linear relationship with the traffic flow on the route (t₁ = α₁ + b₁x₁ ; t₂ b2x2). Determine under what condition (e.g. a relationship among the parameters of the performance functions) tolling cannot reduce the total travel time of the two routes.