Question

What is the effluent concentration of a reactive contaminant
exiting a completely mixed flow reactor after 8 hours of operation?
Assume that after this length of time, the reactor is at steady
state. The volume of the reactor is 100 L and the volumetric flow
rate is 50 L/hr. The influent concentration of the contaminant is
80 mg/L and the rate constant for the decay of the contaminant is
0.5 hr^{-1}.

Answer #1

A reactive contaminant decays according to first order kinetics
with a rate constant of k. A waste stream containing this
contaminant at a concentration of 100 mg/L is treated using an
ideal completely mixed flow reactor having a volume 100 L. At
steady state conditions, the effluent concentration of the
contaminant from the reactor is 20 mg/L. The flow rate of the
influent stream is 50 L/hr. The rate constant at which the
contaminant decays (k) is

A 1.0 � 106 gallon reactor is used in a sewage-treatment plant.
The influent biochemical oxygen demand (BOD) concentration is 100
mg/L, the effluent BOD concentration is 25 mg/L, and the flow rate
through the reactor is 500 gal/min. (a) What is the first-order
rate constant for decay of BOD in the reactor? Assume that the
reactor can be modeled as a comply mixed flow reactor (CMFR).
Report your answer in units of per hour. (b) Assume that the
reactor...

A single completely mixed rectangular reactor is used to treat
troublesome waste. The tank is 180 cubic meters and has a detention
time of 24 hours. The influent concentration is 3.0 moles/liter and
the waste can be reduced by 90% when we assume first-order
kinetics. What would the effluent concentration and percent
reduction be if we fit the reactor with five baffles? These baffles
would divide the tank into six equally sized compartments. Also,
what would the percent reduction be...

A lake with volume 5E6 m3 has a freshwater flow of 20 m3/s.
Waste is dumped into lake at 50 g/s with a decay rate of 0.2/d.
What is the steady state contaminant concentration in the lake in
mg/L if the lake is completely mixed?

A completely mixed activated-sludge process is being designed
for a wastewater flow of (2.64 mgd) using the kinetics equations.
The influent BOD of 120 mg/Lis essentially all soluble and the
design effluent soluble BOD is 7 mg/L, which is based on a total
effluent BOD of 20 mg/L. For sizing the aeration tank, the mean
cell residence time is selected to be10 days and the MLVSS 2000
mg/L. The kinetic constants from a bench-scale treatability study
are as follows: Y...

An activated sludge system has three square reactor tanks in
series (CFSTRs) that are each 60 ft wide, 60 ft long, and 18 ft
deep. The engineers have decided to add a new reactor in parallel.
It will be a plug flow reactor (PFR) with a depth of 18 feet and a
width of 18 feet. The length is to be calculated. The flowrate of
wastewater is 2 MGD and the BOD is 165 mg/L. This will be split in...

A completely mixed activated sludge process is designed to treat
20,000 m3 /d of domestic wastewater having a BOD5 concentration of
250 mg/L following primary treatment. The NPDES permit requirement
for effluent BOD5 and TSS is 20 mg/L for each. The biokinetic
parameters have been established as: yield = 0.6 , k = 5/d, Ks = 60
mg/L, and kd = 0.06/d. The MLVSS concentration in the aeration tank
is to be maintained at 3000 mg/L and the ratio of...

Design a completely mixed activated sludge process using three
different design approaches (i.e. calculate the volume of the
aeration basin). Base your design for the first approach on
detention time, for the second one on BOD loading, and the third
one on kinetics. The influent design flow rate to the activated
sludge process is 10,000 m3 /day with a BOD5 concentration of
200mg/L. Completely mixed activated sludge processes typically have
a detention time ranging from 3 to 6 hours and...

Sooner City Reclamation Plant is a completely mixed activated
sludge process designed to treat 20,000 m3/d of domestic
wastewater having an influent BOD5 concentration of 350
mg/L (assume a 28.6% reduction in during primary treatment). Use
typical activated sludge kinetic constants except for kd
= 0.06 1/d. Assume that the MLVSS concentration in the aeration
basin is maintained at 3,000 mg/L and the ratio of VSS:TSS is 0.75.
Permit requires that the effluent BOD5 and TSS
concentrations do not exceed...

Question 1
You are assigned to carry out a preliminary design for a water
treatment process. A pollutant of concern, denoted ‘A’, is known to
degrade in water. But you do not know the rate law or reaction rate
constant. You conduct a series of experiments. In each case, you
established an initial concentration of 50 mg/L of pollutant ‘A’ in
water in a sealed vessel. After a certain period, you open the
vessel and measure the remaining concentration of...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 5 minutes ago

asked 7 minutes ago

asked 18 minutes ago

asked 41 minutes ago

asked 41 minutes ago

asked 50 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago