The design engineer proposes a fully mixed aeration tank (reactor) with a volume of 25 cubic meters. The wastewater from the community has an average flow rate of 0.009 m3/s and an influent substrate concentration of 300 mg/L as COD. The design safety factor is to be 20. Tests on the wastewater shows that the concentration of settled sludge from the secondary clarifier will be 12,000 mg VSS/L. The reactor kinetic constants are µMAX = 0.4 hr-1, KS = 75 mg/L as COD, Y = 0.4 g VSS/g COD, and kd = 0.004 hr-1. Calculate: a. What is the hydraulic residence time of the reactor? b. What is the minimum allowable sludge age? c. What is the design sludge age? d. What is the biomass concentration in the aeration tank. e. What is the COD concentration in the aeration tank. f. What is the substrate utilization rate (U)? What is the food to microorganism ratio (F/M)? h. What is the recycle ratio and recycle flow rate? g. i. What is the sludge wasting flow rate? j. What is the sludge production rate.

The design engineer proposes a fully mixed aeration tank (reactor) with a volume of 25 cubic meters. The wastewater from the community has an average flow rate of 0.009 m3/s and an influent substrate concentration of 300 mg/L as COD. The design safety factor is to be 20. Tests on the wastewater shows that the concentration of settled sludge from the secondary clarifier will be 12,000 mg VSS/L. The reactor kinetic constants are µMAX = 0.4 hr-1, KS = 75 mg/L as COD, Y = 0.4 g VSS/g COD, and kd = 0.004 hr-1. Calculate: a. What is the hydraulic residence time of the reactor? b. What is the minimum allowable sludge age? c. What is the design sludge age? d. What is the biomass concentration in the aeration tank. e. What is the COD concentration in the aeration tank. f. What is the substrate utilization rate (U)? What is the food to microorganism ratio (F/M)? h. What is the recycle ratio and recycle flow rate? g. i. What is the sludge wasting flow rate? j. What is the sludge production rate.

Structural Analysis

6th Edition

ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

Section: Chapter Questions

Problem 1P

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Concept explainers

Integrated Solid Waste Management

Integrated Solid Waste Management (ISWM) is a thorough waste suppression, compost, removal and recycling Program. An effective ISWM system considers how to suppress, manage and recycle solid waste in a manner that is most efficiently to protect human health and the surrounding. ISWM system requires evaluation of public wants and demands and then selecting and merging the most effective waste management activities for the proposed demands. The main ISWM activities for solid waste management are Waste prevention, Recycling and Composting, and Combustion and Removal and waste collection in a properly planned, constructed, managed and mitigated landfill areas. Each of these requires careful designing, financing, accumulation, and delivery of activities.

Question

The design engineer proposes a fully
mixed aeration tank (reactor) with a
volume of 25 cubic meters. The
wastewater from the community has an
average flow rate of 0.009 m3/s and an
influent substrate concentration of 300
mg/L as COD. The design safety factor is
to be 20. Tests on the wastewater shows
that the concentration of settled sludge
from the secondary clarifier will be 12,000
mg VSS/L. The reactor kinetic constants
are uMAX = 0.4 hr-1, KS = 75 mg/L as
COD, Y = 0.4 g VSS/g COD, and kd =
0.004 hr-1.
Calculate:
a. What is the hydraulic residence time of
the reactor?
b. What is the minimum allowable sludge
age?
c. What is the design sludge age?
d. What is the biomass concentration in
the aeration tank.
e. What is the COD concentration in the
aeration tank.
f. What is the substrate utilization rate
(U)?
g. What is the food to microorganism ratio
(F/M)?
h. What is the recycle ratio and recycle
flow rate?
i. What is the sludge wasting flow rate?
j. What is the sludge production rate.

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