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Mechanical Filtration Is Still the Wastewater Technology of Choice for Many Industries
This is a process in which contaminants in a waste stream are filtered or
screened out. This method is effective in preventing particles, even very
tiny ones like mud and sludge, from moving downstream. The downside is that
solids build up on the filtering media and restrict the water flow requiring
some type of maintenance, such as purging or backwashing. Also, mechanical
filtration is not an effective method for dealing with emulsified oils.
There are three main types of filtration methods—(1) indexing paper filters,
(2) cartridge filters and (3) media filters. A description of each along
with the Pro and Con are listed below:
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Indexing Paper Filters
A very fine paper filter continuously unrolls while the waste stream
flows through the paper filter
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Pro:
Very effective when there’s not a lot of dirt or solids in the waste stream.
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Con:
Solids plug up the paper quickly requiring you to use (buy) a lot of paper;
plus you have to find a way to dispose of the contaminated paper safely.
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Cartridge Filters
per filter is placed inside a canister or enclosed tank.
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Pro:
Provides excellent filtration even down to 5 microns in size.
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Con:
As with indexing paper filters, they can plug quickly and,
depending on the dirt load, must be removed often to clean or replace.
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Media Filters
Other media, like sand or carbon, are used to filter contaminants in the water.
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Pro:
It provides reasonable removal of solids without plugging up.
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Con:
It requires regular maintenance such as backwashing.
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