From there the water is sent into a settling basin, this is where suspended solids settle down
and floating scum is removed by skimmers. Scrapers in the tank move continuously along
the bottom, to deposit the raw sludge into hoppers, which is sent to a nearby plant where
it’s made into pellets for fertiliser. After the settling basins the wastewater is sent to the
next step by Archimedes screw pump, which forces the liquid upwards. The revolution raises
the water thread by thread until it comes out of the top of the cylinder. There it is met by the
fine curve screen, where small items that have made it through the initial screening process
are removed, things like fruit and vegetable stickers. They don’t dissolve and they clog up
the system. Next it’s time to remove the stuff that can’t be seen. Some of the work is done
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by biological aerated filters, where good microorganisms attached to porous rock destroy
the bad microorganisms. The wastewater is pumped up through the rocks and the bacteria I
the water sticks to the rocks. Bubbles are pumped in to keep the good bacteria alive and
working. Then clean water goes up and the rocks with the bad bacteria attached to them
go back down. This cleansed water then flows into a channel on its way to be treated with
Ultraviolet Light. The water passes high output UV lamps where light disrupts the molecular
structure of DNA molecules and microorganisms. This renders the cells unable to replicate
before they die. The disinfection stage takes seconds, eliminates the need for chlorine and
makes the final process much safer.