{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Assignment 3 Fall 2013_SOLN_revised

Assignment 3 Fall 2013_SOLN_revised - University of...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
University of Waterloo DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING EnvE 472 Wastewater Treatment Fall 2013 Assignment #3 In this assignment you will have the opportunity to: - analyze and design aerated lagoons - apply activated sludge process performance equations for organic matter removal 1.) A food processing wastewater that only contains dissolved organic matter is being treated in an aerobic biological wastewater treatment process that can be treated as a CFSTR. The following are the properties that have been determined for the raw wastewater: Average Flow: 1,000 m 3 /day Total COD concentration = 900 mg/L Total BOD 5 concentration = 500 mg/L Assume bCOD/BOD 5 = 1.6 In the bioreactor bCOD is removed and biomass is produced by aerobic heterotrophic biomass. The bioreactor effluent is characterized and found to have the following properties: - Volatile Suspended Solids (Biomass) Concentration = 300 mg VSS/L - Soluble BOD 5 Concentration = 25 mg BOD 5 /L - Assume COD/VSS ratio for grown biomass is 1.42 mg COD/mg VSS Estimate the mass flow of oxygen that was consumed by the biomass in the bioreactor. Solution: O 2 Required = bCOD removed - bCOD biomass = Q (So - S) - 1.42mgCOD/mgVSS * Px Note: Please try out the above form (the method from previous will work, but try and be comfortable with both) Where Px = QXvss Therefore: O 2 Required = Q (So - S - 1.42VSS) = 1000 m3/d [ 800mg/l - 40mg/l - 1.42(300 mg/l)] (1000l/m3)(1 kg/10^6 mg) = 334 kg/d 2.) An aerated lagoon is currently treating a wastewater at a temperature of 17 o C. A sample of the effluent is found to have a bCOD concentration of 15 mg/L.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}