Raw water: refers to natural water or urban tap water without any treatment.
Clarified water: water from which suspended impurities in raw water are removed.
Demineralized water: refers to water in which the cations and anions in the water are substantially removed or reduced to a certain extent. Desalination methods include distillation, electrodialysis, reverse osmosis, ion exchange, and the like.
Turbidity: refers to the degree of turbidity of water, it is due to the optical effect of a certain amount of suspended matter (including colloidal substances) in the water. The unit is expressed in NTU. Turbidity is one of the main characteristics for judging whether or not water is contaminated in appearance. The standard unit of turbidity is defined as a turbidity of 1 degree by 1 mg of SiO2.
Flocculant: an agent that can cause the colloidal particles to form a bridge and flocculate.
Total alkalinity:
refers to the total amount of substances that can neutralize strong acid in
water.
Acidity: refers to the
total amount of substances that can neutralize with strong alkali in water.
Hardness: refers to some
metal ions in water that are easy to form precipitates, usually referred to as
calcium and magnesium ions.
Resistivity: It is also
an indicator reflecting the conductivity of water. The higher the resistivity
of water, the worse the conductivity of water, and the less ions contained in
water. Its common unit is MΩ.CM. It is inversely related to conductivity. For
example, if the conductivity of water is 0.2 μs/cm, its resistivity is 1/0.2=5
(MΩ.CM).
TDS (Soluble Total Solids):
It is the remaining inorganic matter after filtering off the suspended solids
(SS) and colloids and evaporating to see all the water. The unit is ppm or mg/l
and can be measured with a TDS meter. It also reflects the ion content of the
water. It has a rough correspondence with conductivity: for a sodium chloride
reference solution, a TDS value of 1 ppm corresponds to a conductivity of 2
μs/cm.
PH: The relative content of acid and alkali in the solution. The pH is a measure of the negative logarithm (log) of the hydrogen ion concentration in the water. The pH value is 0-14, the pH is 7.0 and the water is neutral; when the pH is less than 7.0, the water is acidic; the pH is greater than 7.0. Then the water is alkaline.
Alkalinity: Alkalinity refers to the content of substances that can be neutralized by [H+] ions and strong acids in water. The alkalinity-producing substances in water are mainly carbonate alkalinity produced by carbonates and bicarbonate alkalinity produced by hydrogencarbonates, and hydroxide alkalinity generated by the presence of hydroxides.
Pure water: refers to the removal of a strong dielectric that is easily removed in water, and the removal of weak electrolytes such as silicic acid and carbon dioxide, which are difficult to remove, to a certain extent. The pure water has a salt content of 1.0 mg/L or less and a conductivity of less than 3 μs/cm.
Ultrapure
water: Also known as high-purity water, it refers to the removal of almost all
conductive materials in water, and the removal of colloidal substances, gases
and organic substances that are not dissociated in water to a very low level of
water. The ultrapure water has a salt content of 0.1 mg/L or less and a
conductivity of less than 0.1 μs/cm. In addition to strict requirements on salt
content or conductivity, pure water and ultrapure water have strict limits on
various metal ion contents, organic matter content, particle size and quantity,
and microbial quantity in water.
Residual chlorine: The
water is chlorinated and disinfected. After contact for a certain period of time,
the remaining chlorine remains in the water.
Total Escherichia coli:
The total coliform group refers to a group of aerobic and facultative
anaerobic, which can ferment lactose when grown at 37 °C, and produce
genotype-free Bacillus bacilli within 24 hours. Total coliform refers to the
number of total coliforms contained per liter of water sample.
Recovery rate: refers to
the ratio of the product water flow to the influent flow rate produced by the
system.
Desalination rate: A parameter that reflects the performance of the membrane. Usually, the desalination rate of the1RO membrane system is above 97%. Can be calculated simply: (raw water conductivity - conductivity of product water) / raw water conductivity.
Salt content: The salt content of water, also called the degree of mineralization, is the amount of salt contained in the water. Since various salts in water are generally present in the form of ions, the salt content can also be expressed as the sum of the amount of various cations in water and the amount of anions.
EDI: Short for continuous electric desalination, it is a new type of ultrapure water preparation technology. It subtly combines electrodialysis technology and ion exchange technology.
