Grit Removal Return to Process Page

What is grit removal and why is it done?     Grit is the material in the wastewater that is composed of small, inorganic solids.  Material like coffee grounds, sand, egg shells and gravel.  This material, like the larger screenings which were removed prior in the process, can not be treated by the wastewater treatment process and can cause excessive wear on the pumps and settling tank drags.      The grit is removed in two long narrow channels that have a "scraper" that drags the grit from the bottom of the channel where the grit settles out, back to an auger where it is lifted out of the channel and deposited into a holding container. When the container is full, the grit is then removed to a landfill for proper disposal. The reason that an auger is used to lift the grit out of the channel is because an auger allows the wastewater that gets pulled up with the grit to flow back into the grit channel where it can proceed to the next stage of treatment which is primary settling.