Author: Site Editor Publish Time: 2023-02-07 Origin: Site
When a feed water conductivity value is obtained, it must be converted to a TDS value so that it can be entered in the software design. For most water sources, the conductivity/TDS ratio is between 1.2 and 1.7. For ROSA design, a ratio of 1.4 for seawater and 1.3 for brackish water is used for conversion, which usually gives a good approximation of the conversion rate.
The following are common symptoms of contamination.
Decrease in water production at standard pressure
The operating pressure must be increased to achieve the standard water yield
Increase in pressure drop between influent and concentrated water
Increase in weight of the membrane element
Significant change (increase or decrease) in membrane removal rate
When the element is removed from the pressure vessel, water is poured on the inlet side of the vertical membrane element, water cannot flow through the membrane element and only overflows from the end face (indicating that the inlet water channel is completely blocked)
When the protective fluid is cloudy, it is likely to be due to microbial growth. Membrane elements protected with sodium bisulphite should be checked once every three months.
When the protective solution becomes cloudy, the element should be removed from the storage seal and re-soaked in a fresh protective solution of 1% (by weight) food grade sodium bisulphite (not cobalt activated) for approximately 1 hour and re-sealed and sealed, and the element should be drained before repackaging.
Theoretically, the incoming RO and IX systems should be free from impurities such as
Suspended matter
Colloids
Calcium sulphate
algae
Bacteria
Oxidising agents, e.g. residual chlorine
Oil or lipid substances (must be below the lower detection limit of the instrument)
Organic substances and iron-organic complexes
Metal oxides such as iron, copper and aluminium corrosion products
The water quality of the incoming water will have a huge impact on the life and performance of the RO element and IX resin.
RO membranes can remove ions and organics very well, and RO membranes have a higher removal rate than nanofiltration membranes. RO can usually remove 99% of the salts in the feed water and ≥99% of the organics in the feed water.
