Fiber Deep Filter for Sewage

Fiber Filter – Deep-Bed Polishing for Sewage & Process Water

A fiber filter uses loose or bundled synthetic fibers (polyester, acrylic, aramid) as a deep, compressible bed to trap suspended solids, colloids and even oil droplets. Water flows downward through a vessel packed with 0.5–2 m of 20–40 µm diameter fibers; the tortuous path provides >95 % removal at 15–30 m h⁻¹ and inlet SS up to 100 mg L⁻¹. When ΔP reaches 0.2–0.3 MPa, the bed is back-washed by air + water scouring that expands and loosens fibers, releasing captured solids in 3–5 min. Fiber balls or bundles can be removed, laundered and reused for 5–8 years, cutting replacement waste. The light weight (bulk density 60–120 kg m⁻³) allows horizontal or vertical installation on roofs or containers. Typical uses include textile dye-house effluent, refinery produced water, RO pre-treatment and tertiary filtration for phosphorus removal. With 80 % less footprint than sand filters, 90 % water recovery and no chemical coagulants required, fiber filters deliver high-rate, low-energy polishing for municipal and industrial sewage works.