Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Past Exam 2 Review Sheet - Environmental Engineering | CE 321, Study notes of Civil Engineering

Material Type: Notes; Class: Environmental Engineering; Subject: Civil Engineering; University: Lafayette College; Term: Fall 2008;

Typology: Study notes

Pre 2010

Uploaded on 08/16/2009

koofers-user-1m3
koofers-user-1m3 🇺🇸

4

(1)

10 documents

1 / 3

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Exam 2 Review - CE 321, Fall 2008
Study homework, notes from class, notes from lab, 2003 Exam
Mix of short answer (30-40%) and problems (60-70%) divided into four sections:
BOD/DO, Reactors, Drinking Water Treatment, Wastewater Treatment
You will be given: Equation sheet, constants, conversion factors, etc
Show your steps, write assumptions, don’t do your work in your head!
Include units with conversions/calculations
Fundamental Principles (Units and Mass Balances)
A. Concentrations (C = M/L3), flow rates (Q = L3/T), mass flow rates (Q*C)
B. Mass balance or continuity equation:
()
rxnCQCQM
dt
d
outoutininCV ±=
CV = fixed volume in space through which mass flows (watershed, lake,
river, reactor)
Applications at steady-state: (LHS = 0)
Applications with a first-order reaction: CVCV VCk
1. DO/BOD/DO Sag curve
DO in streams, Henry’s Law
BOD test: aerobic degradation under controlled conditions
DFDODOBOD fi /)(
5=
kt
eLtL
=0
)( (L = BOD left) )1( kt
ultt eBODBOD
=
DO Sag Curve problems
pf3

Partial preview of the text

Download Past Exam 2 Review Sheet - Environmental Engineering | CE 321 and more Study notes Civil Engineering in PDF only on Docsity!

Exam 2 Review - CE 321, Fall 2008

Study homework, notes from class, notes from lab, 2003 Exam

Mix of short answer (30-40%) and problems (60-70%) divided into four sections: BOD/DO, Reactors, Drinking Water Treatment, Wastewater Treatment

You will be given: Equation sheet, constants, conversion factors, etc

Show your steps, write assumptions, don’t do your work in your head! Include units with conversions/calculations

Fundamental Principles (Units and Mass Balances)

A. Concentrations ( C = M/L 3 ), flow rates ( Q = L 3 /T ), mass flow rates ( Q*C )

B. Mass balance or continuity equation:

( M ) Q C Q C rxn

dt

d CV = in inout out ±

CV = fixed volume in space through which mass flows (watershed, lake, river, reactor)

Applications at steady-state: ( LHS = 0 ) Applications with a first-order reaction: kCCV VCV

1. DO/BOD/DO Sag curve

DO in streams, Henry’s Law

BOD test: aerobic degradation under controlled conditions

BOD (^) 5 =( DOiDOf )/ DF L t = L e −^ kt ( ) 0 ( L = BOD left) ( 1 ) kt BODt BODult e = − −

DO Sag Curve problems

2. Reactors

Design parameters: Hydraulic Retention Time (HRT) = V/Q Surface Loading Rate (overflow rate) = Q/As

Types of Reactors: Batch (no flow through, mixing, not steady-state) PFR (flow through, but no mixing of fluid, like Batch w/ t = HRT ) CSTR (flow through w/ continuous stirring, mixing of fluid)

Zero-order vs. First-order vs. Second-Order Reaction:

Rxn term: kCn dt

dC = − , n is order of reaction

Design equations derived from continuity equation with first order reaction:

Be able to apply mass balance principle to different types of reactors

3. Drinking Water Treatment

SDWA

  • Primary (health-based) and. Secondary (aesthetics) standards
  • Surfacewater filtration Rule

Treatment processes: coagulation, flocculation, sedimentation (settling), filtering, disinfection

- know what these are and how/why they are done

Discrete vs. flocculant settling

  • Stokes Law
  • Jar test
  • Settling tube experiments

Chlorination

  • Chicks Law
  • total and fecal coliform tests
  • CT approach
  • chlorination by-products