Ground Water
The unsaturated zone located immediately above the water table.
What is the Vadose Zone?
In the mass balance equation (ΔS=I−O), this component represents flow leaving the system (e.g., municipal use).
What is Outflow (O)?
The chemical process that turns the dissolved Fe2+ into the more reactive Fe3+.
What is oxidation?
The unit of the first-order kill rate constant (k).
What is time−1 (or min−1 or hr−1)?
The primary treatment method used to remove high Turbidity caused by colloidal solids.
What is Coagulation/Flocculation?
The physical feature that restricts the movement of surface water into the well pipe, preventing contamination.
What is the Grout/Clay Seal?
What a negative ΔS value indicates about a reservoir or aquifer.
What is depletion or that storage is falling?
The two values you need from the Fe(OH)3 formula to calculate its Molecular Weight.
What are the MW of Iron (Fe) and the MW of Hydroxide (OH)?
The required contact time (t) is inversely proportional to this kinetic parameter.
What is the rate constant (k)?
The primary consequence of having a highly acidic pH (like 4.5) on a water distribution system.
What is corrosion of pipes?
The phenomenon where ground elevation drops due to excessive pumping and compaction of an aquifer
What is land subsidence?
The component of Darcy's Law defined by the ratio of the change in hydraulic head to the distance (Δh/ΔL).
What is the Hydraulic Gradient (i)?
The ion's charge or valence (n) used to calculate the Equivalent Weight for Ca2+.
What is 2?
The required percentage of pathogen removal for a 3-log removal.
What is 99.9%?
The general treatment process required to remove dissolved salts like Chloride (Cl−) from drinking water.
What is Reverse Osmosis (RO) (or another membrane process)?
The specific GIS layer or data used to determine the direction of groundwater flow.
What are Piezometric Contours (or Water Table elevation data)?
Given a Δh of 10 m and a ΔL of 200 m, this is the Hydraulic Gradient.
What is 0.05?
The chemical term for concentration defined as moles/liter.
What is Molarity (M)?
If the water temperature drops, this is how the kill rate constant (k) changes, requiring a larger reactor volume.
What is k decreases (slows down)?
Why the dissolved Fe2+ ion must be chemically changed (oxidized) before it can be filtered.
What is because Fe2+ is soluble and too small for physical filtration?
The difference between the Water Table and the Piezometric Surface.
What is the difference between the unconfined and confined aquifer water levels?
A conceptual solution used to restore groundwater balance by actively putting treated surface water back into an aquifer.
What is Artificial Recharge?
The MW of Fe2+ is 55.85 g/mol and Fe(OH)3 is 106.88 g/mol. This is the required mass ratio (Product/Reactant) to calculate sludge mass.
What is 106.88/55.85 (or approx. 1.91)?
A plant treats 50,000 m3/day. If the required t is 0.2 days, this is the minimum required Reactor Volume (V).
What is 10,000 m3? (V=Q⋅t)
The ion created during the Fe(OH)3 precipitation reaction that lowers the pH and consumes alkalinity.
What are H+ ions?