A CSTR activated sludge system is being designed for the Fulton Fish Processing Plant. The flow...

A CSTR activated sludge system is being designed for the Fulton Fish Processing Plant. The flow is relatively small (0.25 mgd), but the wastewater is strong due to all of the fish waste (BOD5 = 4500 mg/L). Primary settling removes 20% of the BOD5. In order to discharge to the town sewer the BOD5 must be reduced to a concentration that is 95% of the influent. What is the Dimensions of the basin assuming a 3:1 L:W ratio. Also, what is the sludge production rate?

Design Parameters

θc = 10 days

X = 2100 mg VSS/L

MLVSS is 75% of MLSS

Aeration Basin = 20 ft deep

Yobs = 0.3 mg MLSS/mg BOD5

Recycle Ratio = 50%

Expert Solution

Ally Wells answered 8 months ago

What is an activated sludge system and what are the processes that occur in the system?...

What is an activated sludge system and what are the processes that occur in the system? What is the role of "mixed liquor suspended solids"? (hint: draw the system diagram and think about what can be happening)

A completely mixed activated sludge process is to be used to treat a flow rate of...

A completely mixed activated sludge process is to be used to treat a flow rate of 2.5 MGD. Design a rectangular activated sludge reactor with a 4:1 ratio of length to width. (design only 1 reactor for all flow). The effluent from the plant must not exceed 15 mg/L of BOD5. Use the following design criteria: a. BOD5 influent = 250.0 mg/L b. MLVSS (X) = 3500 mg/L c. Reactor depth = 11 ft d. Effluent BOD5 must be less...

Design an aeration tank for activated sludge wastewater treatment designed to meet an effluent standard of...

Design an aeration tank for activated sludge wastewater treatment designed to meet an effluent standard of 10 mg/L BOD5. The flow from the primary effluent is 10 m3/min with a primary effluent BOD5 of 250 mg/L. The design calls for the suspended solids to equal 3500 mg/L for an SRT of 5 days. The decay rate constant is 0.03 day-1 and the yield is 0.75 mg/mg. Determine: the tank volume required to meet these specifications, the resulting mass of sludge...

Two types of flow regime are normally used in the design of an activated sludge process,...

Two types of flow regime are normally used in the design of an activated sludge process, namely completely mixed and plug flow (both are continuous). Using first order kinetic reaction, demonstrate which flow regime provide a better performance, given the followings: Q = 550 m3/d t = 6 hours Co = 225 mg/L k = 0.15 d-1

An activated sludge plant receive 5.0 MGD of wastewater with a BOD of 220 mg/L. The...

An activated sludge plant receive 5.0 MGD of wastewater with a BOD of 220 mg/L. The primary clarifier removes 35% of the BOD. The sludge is aerated for 6 hr. The food-to-microorganism ratio is 0.30. The recirculation ratio is 0.2. The surface loading rate of the secondary clarifier is 800 gal/day-ft2. The final effluent has a BOD of 15 mg/L. What are the (a) BOD removal efficiency of the activated sludge treatment processes (secondary BOD removal), (b) aeration tank volume,...

A wastewater plant with the activated sludge process received 5 × 106 L/day of wastewater with...

A wastewater plant with the activated sludge process received 5 × 106 L/day of wastewater with a BOD5 of 500 mg/L. The primary clarifier removes 30% of the BOD and primary clarify effluent has no biomass (Xi=0 mg/L). Recycle (Qr) and waste sludge (Qw) flows are 25% and 2% of Qin, respectively. Effluent BOD5 from secondary clarifier and waste sludge is 20 mg/L. Microorganism concentration in the waste sludge (Xw) is 6,000 mg/L. Soluble BOD5 is biologically converted into CO2...

A completely mixed activated sludge plant is not performing particularly well. You calculate a F:M of...

A completely mixed activated sludge plant is not performing particularly well. You calculate a F:M of 1.5 mg/mg·day-1. What would you recommend to solve the problem? a. Raise the pH b. Increase the dissolved oxygen concentration in the aeration tank c. Lower the pH d. Reduce the amount of sludge wasted

Design a set of activated sludge aeration tanks. The flow rate to treat is 5.6 MGD...

Design a set of activated sludge aeration tanks. The flow rate to treat is 5.6 MGD and the BOD concentration is 150 mg/L. The design solids concentration (X) at steady-state is 2,000 mg/l. The design MCRT is 7 days. The kinetic coefficients are as follows: K = 2 g BODg cells⋅d, Ks = 25 BOD/L, Kd = 0.06 day-1, Y = 0.5 g BODg cells⋅d. The influent ammonia concentration is 40 mg/l and nitrification is needed. It takes 1400 ft3of...

draw a schematic diagram of an activated sludge system that includes a "selector". describe the function...

draw a schematic diagram of an activated sludge system that includes a "selector". describe the function of the "selector" and describe how this process configuration and associated operating strategy is different from a "conventional" activated sludge system.

A conventional activated-sludge plant treats 10.0 MGD of municipal wastewater with a BOD concentration of 240...

A conventional activated-sludge plant treats 10.0 MGD of municipal wastewater with a BOD concentration of 240 mg/l and suspended solids of 200 mg/l. The sludge flow pattern is shown in Figure 11-1 of the textbook with a gravity belt thickener to concentrate the excess activated sludge. Primary and thickened activated sludge are pumped separately to the anaerobic digester. The primary clarifier removes 50% of the suspended solids and 35% of the BOD. The primary sludge solids content is 4.0%. The...

Question