What are the classifications of raw water quality referenced in the design of purified water systems

What is the relationship between water quality grade and purified water system design? Purified water equipment manufacturers in the system design, usually to the user to use the raw water quality report as an important basis for design reference, today we will talk about the classification of raw water and why the purification water design should pay attention to the quality of
raw water.
According to the environmental functions and protection goals of surface water waters, China divides the water quality level into five categories, and the distinction between each level of water from the functional use is more obvious
.
Fig.
1 Category
I purified water equipment It is mainly applicable to source water and national nature reserves
.
This type of water can be used as drinking water
after simple treatment and disinfection.
Typical Class I water quality lakes are Erhai Sea, Fuxian Lake, Lugu Lake and Bangong Lake, while the famous Qiandao Lake is an important reservoir
for Class I water quality.
Class I water is mostly clear to the bottom of Class II
.
It is mainly applicable to the first-class protection area of the surface water source of centralized drinking water, the habitat of aquatic organisms, the spawning grounds of fish and shrimp, and the feeding grounds of juvenile fish
.
Class II water can also be used as drinking water
after purification treatment (such as flocculation, precipitation, filtration, disinfection, etc.
).
Class III
.
It is mainly applicable to the secondary protection area of centralized drinking water surface water source, fish and shrimp wintering ground, migratory passage, aquaculture area and other fishery waters and swimming areas
.
This type of water needs to be deeply treated before it can be used for
domestic consumption.
Class
IV.
It is mainly suitable for general industrial water areas and recreational water areas
that are not directly touched by the human body.
Class
V.
It is mainly applicable to agricultural water areas and general landscape requirements of waters
.
Class V or inferior class V, the degree of pollution has exceeded the class V water quality level is measured according to the amount of dissolved oxygen contained in the water, metal elements, microorganisms, chemicals and other up to 80 indicators
.
Of course, the difference in the appearance characteristics of various types of water is still relatively obvious
.
Because of the different water quality, so different types of raw water into the purified water equipment, in order to get the applicable and meet the requirements of the purified water, in the pretreatment and reverse osmosis process of its process requirements are not the same, the worse the water quality of the filtration process requirements, the same reason
.
Therefore, designers in purified water use the raw water report as an important reference for
process design.