The effect of different dewatering techniques on resulting effluent particle size.

Abstract

A paucity of literature has compared geotextile dewatering methods to more conventional dewatering methods (i.e. centrifuge, sedimentation) in the context of how geotextile dewatering performs at reducing particulate matter in dewatering effluent. Particulate matter is the primary source of inorganic and organic contaminants (i.e. dioxins and furans) in an unconsolidated sediment (estimated 577,000 m3) that has accumulated in a wastewater stabilization basin in Nova Scotia, Canada. Physical and chemical properties of contaminated sediment were initially characterized, and subsequent laboratory experiments were carried out for three common dewatering methods: sedimentation, centrifugation, and geotextile filtration. Filtrate quality of suspended solids (number, particle size distribution of particles) was examined for differences based on three dewatering techniques assessed. All three methods provided effective removal of particulate matter during dewatering, but geotextile dewatering could be a more cost-effective and practical solution for dewatering of these sediments.