Experiment 4 Coagulation and Flocculation (Jar Test) : Wastewater Engineering (EAT 303/4) Laboratory Module
Experiment 4 Coagulation and Flocculation (Jar Test) : Wastewater Engineering (EAT 303/4) Laboratory Module
Experiment 4 Coagulation and Flocculation (Jar Test) : Wastewater Engineering (EAT 303/4) Laboratory Module
EXPERIMENT 4
2.0 INTRODUCTION
Colloid Stability
The particles in the colloid range are too small to settle in a reasonable
time period, and too small to be trapped in the pores of a filter that
makes sedimentation or filtration difficult. For colloids to remains
stable they must remains small. Most colloidal are stables because
they possess a negative charge that repels other colloidal particles
before they collide with one another. The particles migrate to the pole
of opposite charge at a rate proportional to the potential gradient.
Generally, the larger the surface charge, the more stable the
suspension.
Colloid Destabilization
Such that each mole of alum added uses six moles of alkalinity and
produces six moles of carbon dioxide. The above reaction shifts the
carbonate equilibrium and decrease the pH. However, as long as
sufficient alkalinity is present and CO2 (g) is allowed to evolve, the pH
is not drastically reduced and is generally not an operational problem.
When sufficient alkalinity is not present to neutralize the sulfuric acid
production, the pH may be greatly reduced:
3.1 Chemicals
a) Alum solution
b) H2SO4 or NaOH
c) Water sample
3.2 Apparatus
a) 1 liter beaker
b) pH meter
c) Turbidity meter
d) Pipette
e) Jar test
6.0 DISCUSSION
(Include a discussion on the physical interpretation of the result, the
reasons on deviations of your finding from expected results, your
recommendations on further experimentation for verifying your result
and your finding).
7.0 CONCLUSION
(Based on data and discussion, make your overall conclusion).