CHBT Water Treatment Systems for Dialysis 2

Question 1

What does total dissolved solids (TDS) measurement indicate in a water treatment system?

Accepted Answer

The overall ionic load in the water; high TDS after the RO suggests membrane failure

Answer

TDS is a proxy measure of the RO membrane's rejection efficiency. A rising TDS in product water indicates the membrane may be failing, allowing contaminants to pass through. It is monitored continuously by the machine's conductivity sensor.

Question 2

What is the purpose of the distribution loop in a dialysis facility water system?

Accepted Answer

To continuously circulate purified water to all dialysis stations, preventing bacterial stagnation

Answer

The distribution loop keeps purified water moving continuously at a velocity that prevents biofilm formation. Dead legs (stagnant sections) in the loop are a primary source of bacterial contamination.

Question 3

Why must a dialysis water treatment system use two activated carbon beds in series?

Accepted Answer

To provide a redundant safety barrier; the first bed removes most chloramines and the second confirms complete removal

Answer

Two carbon beds in series provide a safety redundancy. Testing is performed between the two beds; if the first bed breaks through, the second provides backup protection. A single bed with no verification point is insufficient for patient safety.

Question 4

What chemical is commonly used to disinfect a hemodialysis water distribution loop?

Accepted Answer

Peracetic acid or sodium hypochlorite (bleach)

Answer

Peracetic acid and sodium hypochlorite are the most common loop disinfectants. They must be thoroughly rinsed out and residuals verified before the system is returned to service. Formaldehyde is being phased out due to toxicity.

Question 5

Which contaminant in dialysis water is associated with aluminum bone disease and encephalopathy in dialysis patients?

Accepted Answer

Aluminum

Answer

Aluminum contamination from municipal water or aluminum-containing flocculants accumulates in dialysis patients, causing aluminum bone disease (adynamic bone disorder) and dialysis encephalopathy (dementia-like syndrome).

CHBT - Certified Hemodialysis Bio-Medical Technician Practice Test

CHBT - Certified Hemodialysis Bio-Medical Technician Practice Test

CHBT Water Treatment Systems for Dialysis 2