Question

In: Civil Engineering

A domestic wastewater with a flow of 1700 m3 / day will be treated in a...

A domestic wastewater with a flow of 1700 m3 / day will be treated in a biological treatment plant. Wastewater pre-settling tank effluent BOD value is 350 mg / L. If the volume of the biological reactor (ventilation reactor) is 500 m3, do you prefer a fully mixed or plug-flow reactor? Please explain the reasons.

Solutions

Expert Solution

for both plug flow and completely mixed condition effluent concentration after biological treatment is same and the volume of reactor is fixed. hence we can choose the economical reactor. since completely mixed reactor uses external energy for mixing and plug flow doesn't need any energy, plug flow reactor is more economical than completely mixed reactor for the given conditions. hence choose plug flow reactor.


Related Solutions

The total flow at a wastewater treatment plant is 682 m3/day. The purpose of the plant...
The total flow at a wastewater treatment plant is 682 m3/day. The purpose of the plant is to remove compound Z from the wastewater by treating it in reactors, using a newly developed microbial process. Assume the microbial treatment can be modeled as a first order reaction with a rate coefficient of 0.36/h. Suppose the flow is split evenly and treated in two parallel reactors– one complete mix and one plug flow -- each with a volume of 88 x...
A municipal wastewater treatment plant discharges 20,000 m3/d of treated wastewater to a stream. The wastewater...
A municipal wastewater treatment plant discharges 20,000 m3/d of treated wastewater to a stream. The wastewater has a BOD5 of 30 mg/L with a k1 of 0.23 d-1. The temperature of the wastewater is 20 oC, and the dissolved oxygen is 2.0 mg/L. The stream just above the point of wastewater discharge flows at 0.65 m3/s, has a BOD5 of 5.0 mg/L, and is 90% saturated with oxygen. The temperature of the stream is also 20 oC. After mixing, the...
A factory disposes 1.1 m3/s of treated industrial wastewater into a river. The wastewater has an...
A factory disposes 1.1 m3/s of treated industrial wastewater into a river. The wastewater has an ultimate biochemical oxygen demand of 25 mg/L and dissolved oxygen of 2 mg/L. Just upstream of the wastewater outfall, the river has a flow rate of 10 m3/s, ultimate biochemical oxygen demand of 6 mg/L, and oxygen deficit of 2 mg/L. At the river temperature, the saturation concentration of dissolved oxygen is 9 mg/L. The deoxygenation coefficient is 0.19 d-1 and reaeration coefficient is...
The Wilson Wastewater Treatment Plant currently provides primary treatment for a flow rate of 2500 m3/day....
The Wilson Wastewater Treatment Plant currently provides primary treatment for a flow rate of 2500 m3/day. The effluent from the primary tank has a soluble BOD5= 240 mg/L. You need to design an activated sludge treatment to update the plant. The secondary effluent standards to meet are 25.0 mg/L BOD5 total (suspended and soluble BOD) and 30 mg/L suspended solids. Use the following assumptions: Target soluble BOD5 in the effluent of the secondary treatment is 2.5 mg/L. Growth constants can...
A grit chamber is designed to treat an average wastewater flow of 1 m3/sec at an...
A grit chamber is designed to treat an average wastewater flow of 1 m3/sec at an overflow rate of 4752 m3/m2 –d to capture sand with the following particle size distribution:          % by wt.                        Diameter (mm)                30                                         1.0                30                                         0.5                30                                         0.2                10                                         0.1 The design overflow rate is such that 100% removal of the 0.5 mm diameter particles will be achieved. The operating temperature is 20°C and the specific gravity of the sand particles...
An industrial wastewater flowing at a rate of 37,000 m3/day is contaminated by 187 mg/L of...
An industrial wastewater flowing at a rate of 37,000 m3/day is contaminated by 187 mg/L of propanol – CH3CH2CH2OH. As an environmental consultant, you propose to treat the water in an activated sludge process in which propanol is oxidized by oxygen into carbon dioxide – CO2. The reaction is highly favorable and assumed to be complete. a) Equilibrate the half-reactions and overall reaction that are expected to occur during the treatment process. b)Determine the theoretical quantity of oxygen (in mol/day)...
The following are average operating data from a secondary activated sludge: Wastewater flow = 29160 m3/d...
The following are average operating data from a secondary activated sludge: Wastewater flow = 29160 m3/d Vol. of aeration tanks = 8400 m3 Influent SS = 120 mg/L Influent BOD5 = 170 mg/L Effluent SS = 22 mg/L Effluent BOD5 = 20 mg/L Volatile fraction of mixed liquor and effluent suspended solids is 0.65. Mixed liquor suspended solids = 2500 mg/L Waste sludge flow = 200 m3/d SS in Waste sludge = 9800 mg/L Determine the following: Aeration period, Food...
Your task is to build a wastewater treatment plant to handle all of the domestic wastewater...
Your task is to build a wastewater treatment plant to handle all of the domestic wastewater produced by a housing estate. Using population equivalent, PE = 65000, design, describe and calculate briefly the sizes of all the unit processes in the treatment plant that are going to be built. You may assume the value that is not given.
Your task is to build a wastewater treatment plant to handle all of the domestic wastewater...
Your task is to build a wastewater treatment plant to handle all of the domestic wastewater produced by a housing estate. Using population equivalent, PE = 65000, design, describe and calculate briefly the sizes of all the unit processes in the treatment plant that are going to be built. You may assume the value that is not given.
Your task is to build a wastewater treatment plant to handle all of the domestic wastewater...
Your task is to build a wastewater treatment plant to handle all of the domestic wastewater produced by a housing estate. Using population equivalent, PE = 65000, design, describe and calculate briefly the sizes of all the unit processes in the treatment plant that are going to be built. You may assume the value that is not given.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT