Final Exam - Erosion
and Sediment
Control(67 questions
and answers)
if erosion control practices fail - answer sediment-
laden stormwater runoff will still be a concern
WHAT IS THE PROBLEM? - answer Sediment-laden
water contains very fine colloidal silt and clay
particles Particles stay in suspension for a
extended period of time
Flocculants - answer Facilitate coagulation and
flocculation Increases sedimentation rate
Decreases detention time
Flocculant def - answer is a chemical additive that
acts as a binder for soil particles
Colliods - answer (small particles, sometimes
magnetically charged) which remain in suspension
and are difficult to settle out
, Flocculation Agents (3 Types) - answer Aluminum
sulfate (alum) - neutral ionic charge (pH
dependent)
Polyacrylamide - can be cationic, anionic, or
nonionic (soil specific)
Chitosan - cationic
Flocculant Types - answer Synthetic- Cationic,
Anionic, Nonionic, PAM
Inorganic- low MW, small size, Alum, PAC
Bio/Natural- Polysacchariades, Tannins, Celluslose,
Starch
Stimuli Responsive- Thermo, pH, Electromagnetic
responsive
Flocculant Charges - answer Anionic (-) nontoxic
Cationic (+) toxic
Nonionic (no charge) nontoxic
and Sediment
Control(67 questions
and answers)
if erosion control practices fail - answer sediment-
laden stormwater runoff will still be a concern
WHAT IS THE PROBLEM? - answer Sediment-laden
water contains very fine colloidal silt and clay
particles Particles stay in suspension for a
extended period of time
Flocculants - answer Facilitate coagulation and
flocculation Increases sedimentation rate
Decreases detention time
Flocculant def - answer is a chemical additive that
acts as a binder for soil particles
Colliods - answer (small particles, sometimes
magnetically charged) which remain in suspension
and are difficult to settle out
, Flocculation Agents (3 Types) - answer Aluminum
sulfate (alum) - neutral ionic charge (pH
dependent)
Polyacrylamide - can be cationic, anionic, or
nonionic (soil specific)
Chitosan - cationic
Flocculant Types - answer Synthetic- Cationic,
Anionic, Nonionic, PAM
Inorganic- low MW, small size, Alum, PAC
Bio/Natural- Polysacchariades, Tannins, Celluslose,
Starch
Stimuli Responsive- Thermo, pH, Electromagnetic
responsive
Flocculant Charges - answer Anionic (-) nontoxic
Cationic (+) toxic
Nonionic (no charge) nontoxic
