The Condition Of Water Flashcards
What percentage of Earth’s water is naturally fresh?
3%
Of Earth’s natural fresh water, how much can be easily sourced?
- 1% groundwater
0. 3% surface water
What water contaminants are not known to be harmful but should still be removed in treatment where possible?
Micropollutants from cosmetics and medications
Why is temperature important in water treatment?
It affects key properties such as solubility, precipitation of solids and biological activity
How is the carbon content of water divided?
Inorganic, organic, dissolved organic
How are the presences of various compounds in water measured?
pH, alkalinity, hardness, conductivity
What is the source of most organic compounds in water?
Microbial degradation in soil
What are the three types of particulate and what separates them?
Solution: cannot be filtered, does not scatter light
Suspension: can be filtered, can scatter light
Colloid: cannot be filtered, can scatter light
How are total solids determined?
Evaporation overnight at 103-105 degrees C
How are total fixed solids determined?
Ignition of total solids in a muffle furnace
How are total volatile solids determined?
Total solids minus total fixed solids
How are total suspended solids determined?
1 hour of filtration and drying
How are total dissolved solids determined?
Drying of the liquid product of the 1 hour of filtration
What is the desirable limit of dissolved solids?
<500ppm
What is turbidity?
A measure of light scattering
What is Avogadro’s number?
6.022x10^23
What is a Dalton?
An atomic mass of 1 Dalton means 1 mol weighs 1g
When finding equivalents, how is charge important?
Substances with charges more positive or negative than 1 just be multiplied in equivalent quantity by the charge
What are the ions that affect water pH?
Hydrogen H+ and Hydroxide OH-
What is a buffer solution?
A solution which resists pH change
What is the equation for alkalinity of water?
[HCO3 -]+2[CO3 2-]+[OH-]-[H+]
What is alkalinity typically expressed in?
Calcium carbonate equivalent (CaCO3)
How is alkalinity measured?
By the amount of strong acid that is required to reduce the pH of the solution to 4.2
What is the main cause of scale buildup?
Carbonate/temporary hardness
