Disc filter pre-screen dual media disc filter

A two-stage method of filtering wastewater comprising the steps of:

• exposing wastewater to be filtered to an exterior of a first stage rotary drum filter;
• causing a wastewater filtrate to pass through an exterior filtration surface of the first stage rotary drum filter into an interior of the first stage rotary drum filter while capturing larger solids with the exterior filtration surface;
• flowing filtrate which has passed into the interior of the first stage rotary drum filter to an axially aligned adjacent central drum of a second stage rotary disc filter having a plurality of adjacent filter segments positioned around the central drum, each of the plurality of adjacent filter segments defining a cavity in fluid communication with one of a plurality of drum apertures, each disc segment having filter media with pores sized to capture solids smaller than the exterior filtration surface of the first stage rotary drum filter;
• and
• causing the filtrate to flow out of the cavity through the filter media, capturing smaller solids on an inside surface of the filter media, with the captured smaller solids remaining within the cavity of the filter segments.