4.2.AWWTP is to treat 5 MGD of wastewater using activated sludge. Five sets of aeration tank followed by five secondary clarifiers to be used of which four of them to be working at any time. The MLSS is 1400 mg/L. What is the solids loading rate if the cross section area is 300 ft² and the flow rate of activated sludge need to be returned from the recycling line is 30%? b) 76 Ib/d.ft² c) 51 Ib/d.ft² d) 63Ib/d.ft² a) 46 Ib/d.ft² 4.3.Two machines working in a room measures (40 m x 10 m x 5 m). Every machine emits an air pollutant (MW=106 g/mole) at a rate of 230 mg/hr. Assume the air pollutant is conservative. How many air changes per hour are needed to maintain a concentration of 0.1 ppm in a STP of 1 atm. and c) 0.76 change/hr d) 1.25 change/hr 25°C? b) 0.53 change/hr a) 0.25 change/hr

2. The average wastewater flow from a community of 20,000 is 125 gpcd. The 5 day, 20 deg C BOD is 250 mg/L. The suspended solids content is 300 mg/L. A final plant effluent of 50 mg/L of BOD is to be achieved through the use of two sets of identical settling tanks and trickling filters operating in parallel. The settling tanks are to be designed to a standard of 1000 gpd/^2. The trickling filters are to be 6^ deep and operated at an organic loading of 55 lbm/1000^3 d. There is no recirculalon. (1) What settling tank surface area is required? In ft^2 (2) What settling tank diameter is required? In ft (3) Estimate the BOD removal in the settling tanks? In percent % (4) What is the trickling filter diameter? In ft File Explorer O Expert Q&A | Cheq... (66) These

2. The average wastewater flow from a community of 20,000 is 125 gpcd. The 5 day, 20 deg C BOD is 250 mg/L. The suspended solids content is 300 mg/L. A final plant effluent of 50 mg/L of BOD is to be achieved through the use of two sets of identical settling tanks and trickling filters operating in parallel. The settling tanks are to be designed to a standard of 1000 gpd/^2. The trickling filters are to be 6^ deep and operated at an organic loading of 55 lbm/1000^3 d. There is no recirculalon. (1) What settling tank surface area is required? In ft^2 (2) What settling tank diameter is required? In ft (3) Estimate the BOD removal in the settling tanks? In percent % (4) What is the trickling filter diameter? In ft domeved Ward

2. The average wastewater flow from a community of 20,000 is 125 gpcd. The 5 day, 20 deg C BOD is 250 mg/L. The suspended solids content is 300 mg/L. A final plant effluent of 50 mg/L of BOD is to be achieved through the use of two sets of identical settling tanks and trickling filters operating in parallel. The settling tanks are to be designed to a standard of 1000 gpd/^2. The lbm/1000*3 Ibm/1000.^3.d. trickling filters are to be 6^ deep and operated at an organic loading of 55 There is no recirculalon. (1) What settling tank surface area is required? In ft^2 (A) 2500 ft^2 (B) 3000 ft^2 (C) 3500 ft^2 (D) 4500 ft^2 (2) What settling tank diameter is required? In ft (A) 40 ft (B) 50 ft (C) 65 ft (D) 80 ft (3) Estimate the BOD removal in the settling tanks? In percent % (A) 15% (B) 30% (C) 45% (D) 60% (4) What is the trickling filter diameter? In ft (A) 65 ft (B) 75 ft (C) 85 ft (D) 95 ft

The City of Marietta has been directed by the City Board to upgrade its primary Wastewater Treatment Plant (WWTP) to include a secondary treatment process that can meet an effluent standard of 20 mg/L of BODs and 20 mg/L of suspended solids (SS). They want to select completely mixed activated sludge system. The BOD5 of the SS is estimated to be 50% of the SS concentration. Assume L:W within 4:1 and maximum depth of 4.5 m and maximum length of 50 m for the tank. Assume the reasonable values of missing parameters from FE Exam Handbook. The effluent characteristics from the primary treatment process are: Flow = 0.150 m's, BOD5 =75 mg/L. Assume the values for the growth constants as K, = 100 mg/L BOD5, Mm = 2.5 d-1, kg = 0.05 d'1. Y = 0.50 mg VSS/mg BODs removed, MLVSS = 2,800 mg/L, MISS - 1.20 (MLVSS), wastewater temperature = 25.0°C. Assume 8% 02 transfer rate and BOD5 to BODu ratio as f = 68%. If SRT (qc) = 14.5 days, the volume of the aeration tank is nearly?

used for canitary land6110/10.. (b) A slaughterhouse generated 1036.8 m³/d of wastewater each day. The average soluble BODs and MLVSS (X) of the treated wastewater after primary settling is 966 mg/L and 2000 mg/L, respectively. The aeration tank has effective dimensions of 8.0m (W) x 8.0m (L) x 5.0m (D). Determine the aeration period and F/M ratio. (a) Dies

An aeration basin of volume 200 m3 operates at a MLSS of 2500 mg/l. The daily sewage flow is 1500 m3 with an average BOD of 230 mg/l. The concentration of suspended solids in the effluent amounts to 60 mg/l. If the average waste sludge solid is 75 kg/d, compute the: a) Detention time in hours. b) F/M ratio. c) BOD sludge age or MCRT in days.

An activated sludge wastewater treatment system was designed and operated in a steadystate under the following conditions:• Reactor volume of 10,000 m3in total;• Sludge concentration (MLSS) of 3200 mg/L in the reactor;• Return sludge concentration at 8000 mg/L (the underflow of the secondary clarifier)• Each day, 400 m3 of underflow sludge (return sludge) was wasted as excesssludge;What is the average Sludge Residence Time (SRT)?

For an activated sludge basin with a flow rate of 500 L/s if the influent BOD5 = 100 mg/L, the MLVSS = 3000 mg/L and the volume of the aeration basin = 766100 gallons Find the F/M ratio If the WAS  X= 10000 mg/L, find the WAS flowrate (m3/d)

The concentration of suspended solids in the flow is 2500 g/m3. Knowing that (SS) come into the clarifier each day is (31275 Lbs/day). Determine The flow to a clarifier in MGD ? Select one: O a. 1.5 O b. 1.2 O c. None O d. 1.3