CWS Iron, Manganese & Hydrogen Sulfide Removal 2

Question 1

When iron bacteria are confirmed in a water supply, which treatment approach is most appropriate?

Accepted Answer

Chlorine injection followed by contact time and filtration

Answer

Iron bacteria require disinfection with chlorine (or another oxidant) to destroy the organisms before filtration removes the resulting solids.

Question 2

Potassium permanganate (KMnO4) is used in water treatment primarily to:

Accepted Answer

Oxidize iron, manganese, and hydrogen sulfide

Answer

Potassium permanganate is a strong oxidizer that converts dissolved iron, manganese, and hydrogen sulfide into filterable precipitates.

Question 3

To avoid pink or purple staining of fixtures, how should potassium permanganate dosing be controlled?

Accepted Answer

Achieve complete oxidation with no excess residual

Answer

Excess potassium permanganate residual in treated water will stain fixtures pink or purple, so dosing must not exceed what is consumed during oxidation.

Question 4

Birm filtration media removes iron and manganese primarily through which mechanism?

Accepted Answer

Catalytic oxidation

Answer

Birm uses dissolved oxygen already present in the water as a catalytic oxidizer to convert dissolved metals into filterable particles.

Question 5

A customer reports persistent black staining on fixtures and darkened laundry. Which contaminant is the most likely cause?

Accepted Answer

Elevated manganese levels

Answer

Manganese oxidizes to form black or brownish-black precipitates that stain fixtures, laundry, and plumbing components.

(CWS) Certified Water Specialist Practice Test

(CWS) Certified Water Specialist Practice Test

CWS Iron, Manganese & Hydrogen Sulfide Removal 2