Filtration of municipal sewage by ring shaped floating plastic net media

Floating Filters for Particle Removal in Sewage Treatment

“…Generally, the medium is coarse (2-10 mm), giving a high porosity and consequently a high sludge accumulation capacity and a low head-loss. ' The floating filters have been operated at high filtration rates (5-50 m/h)(2.6.7-R, 9). T h e low head-loss and long filter run times make these coarse filters of interest for various applications both as a roughing primary filter and as an intermediate separation reactor after biological or chemical pretreatment.…”

Physicochemical processes

“…However, low density filter materials are not described well because of disruption of the media structure caused by the rapidly rising air. Tanaka et al (1995) studied the characteristics of floating media filtration as a process for primary treatment of municipal wastewater during dry weather and high-rate treatment of combined sewer overflow during stormy weather. The floating media used consisted of a ring-shaped polypropylene net (2.2 em diameter, 2.5 em length, 6 mm mesh size) with a void ratio of 90%, specific gravity of 0.93, Literature Review 1996 Treatment Systems and filter depth of 2 m. Suspended solids and BODs removals of 80 to 90% and 44%, respectively, were achieved at a filtration rate of 1000 mlday and addition of 2 to 3 mglL of cationic polymer.…”

Filtration performance of a plastic‐sand dual‐media filter

“…Results showed that the floating filters could be used as roughing filters (prefilters) to upgrade subsequent rapid filtration performance such as lower head loss and longer filter run. They could provide higher SS removal per unit head loss, compared with conventional anthracite-sand filters (Mouri and Niwa, 1993;Tanaka et al, 1995; Downloaded by [University of Tasmania] at 11:51 30 September 2015 Vigneswaran, 1995, 1996). These studies were mainly focused on applications of floating media in single-medium filters.…”