An important part of operating membrane systems is accurate data collection on a daily basis. The data will help predict normal maintenance schedules and will help determine the cause of any system upsets. Comprehensive data is very useful in determining when the membranes need to be chemically cleaned, or eventually replaced. It also alerts the operator to changes taking place such as fouling, leaking “O” rings etc.
Pretreatment Equipment - Theory of Operation
Some raw feed waters contain suspended particulate material. This material is commonly sand, iron oxides, clay or elemental sulfur.
Introduction of such materials into the membrane system can cause the development of excessive system differential pressure (dP), or even complete blockage of the brine channels with the resultant reduction of permeate flow. It can also cause physical damage to the membranes themselves. This usually results in a decrease of permeate quality and reduction of membrane life. Cartridge filtration is normally a simple and cost-effective way to reduce the amount of particulate matter reaching the membrane surface.
Membrane filtration systems are helping water treatment providers simplify and automate their processes while significantly improving water quality. Replacing or augmenting conventional treatment with membrane processes helps avoid heavy use of chemical processes and methods and can provide a superior finished water quality.
It is important to check on the level of semi-colloidal suspended solids in the feedwater to RO systems. The level can be estimated (not measured absolutely) by the Silt Density Index or SDI test which measures the blocking rate of a 0.45 micron filter pad under controlled pressure conditions.