Environmental Technology ChimH409 (2-0-1)

Michel Verbanck

mikeverb@ulb.ac.be

2012

Universite Libre de Bruxelles Welcome @ BrufaceDept Water Pollution Control

Course structure

 Part 1. Introduction (incl. generic methods) Part 2. Air pollution control engineering  Part 3. Water & wastewater treatment

Part 4. Solid and hazardous wastes

 Part 3.

Water & wastewater treatment 

Total Solids ( 400 –1200 mg/L) often a function of parasitic clearwater infiltration into the sewers

Inorganic (ash)50%

Organic (volatile)50%

Dissolved inorg. 35%

Suspended (>1 µm) 45%(15% inorg) (30% org)

Dissolvedorganic20%

Non-settleableinorganic40%

Settleable (“>10µm”)25% (10% inorg ; (15% organic)

Non-settleableorganic

35%

Typical composition of untreated domestic wastewater

Archimedes screws for initial wastewater pumping

bar screen separation

Grit and grease removal

counter-current washing and extraction of the grits

Typical steps in municipal wastewater treatment

DECANTATION

Gravity – Archimedes buoyancy

2236 sss vdBdvAgd

Terminal settling velocity vs

DECANTATION

Terminal settling velocity vs

2

22

22

36

sss vdBdvA

ρυ

gd

We define dvdg

Ar s PRe3

2

bbAra 2ReP a = 1.096 b = 13.86

Gravity – Archimedes buoyancy

vs

= vs d

vs

Boycott effect

vs can now be reduced to

LAMELLA SETTLING TANKS:Shortening the settling distance

Pipebundlesalso used

Actiflo process (OTV - Krüger)

coagulation, flocculation, settling assisted by 125µm microsand injection, lamellar gravity separation

residence time lower than 15 min

Module for flow repartition(between dry-weather and wet-weather treatment lines)

Parshall flume for flow-rate measurement (at the outlet of the plant)