A liquid (2), such as wastewater, is filtered using a liquid-permeable filtering element (9) having first and second faces (10, 11) so as to produce filtered liquid (4) having total suspended solids of no more than 10 mg/L. The method comprises cycling the liquid-permeable filtering element through the liquid whereby, in a first position, an area of the first face of the filtering element is subjected to liquid under pressure and a pressure across the filtering element is greater than 0 and less than or equal to 5.9 kPa (60 cmH2O), and, in a second position, the area is not subjected to liquid under pressure or is subjected to liquid at a lower pressure, and solids accumulated on the first face of the filtering element can be removed by directing at least one jet at the second face of the filtering element through the filtering element towards the first face.

A liquid (2), such as wastewater, is filtered using a liquid-permeable filtering element (9) having first and second faces (10, 11) so as to produce filtered liquid (4) having total suspended solids of no more than 10 mg/L. The method comprises cycling the liquid-permeable filtering element through the liquid whereby, in a first position, an area of the first face of the filtering element is subjected to liquid under pressure and a pressure across the filtering element is greater than 0 and less than or equal to 5.9 kPa (60 cm H.sub.2O), and, in a second position, the area is not subjected to liquid under pressure or is subjected to liquid at a lower pressure, and solids accumulated on the first face of the filtering element can be removed by directing at least one jet at the second face of the filtering element through the filtering element towards the first face.

A rotary disc filter device includes a rotary drum and one or more disc-shaped filter members secured about the drum. Each disc-shaped filter member includes a filter and a filter support comprising a series of modules. The modules each include a base that is secured to the rotary drum and a support arm projecting outwardly from the base. The modules are interconnected and disposed around the rotary drum.

Water or wastewater filtration systems and processes have a filter tank having a floor and sidewall defining a filtration zone, an influent conduit, and an effluent conduit. One or more filtration members in the tank having filter media, and one or more cleaning members adjacent at least some portions of the filter media. Generating an effluent stream by generating a pressure differential across submerged portions of the filtration media, causing water in the influent to flow from outside to inside the submerged portions of the filter media. A prime mover rotates the filtration members. A blower and chamber for creating a reduced pressure condition in each of the cleaning members when they are non-submerged, the chamber receiving wet solids removed from non-submerged, wet solids-laden portions of the filter media by the non-submerged cleaning members subsequent to submerged, fouled portions of the filter media being rotated out of the filtration zone.

A device is provided for cleaning a filter cloth that forms a part of a filter element in a rotary disc filter. The device includes a flush tube and a spray nozzle operatively connected to the flush tube for receiving a cleaning fluid from the flush tube and directing the cleaning fluid onto the filter cloth.