Solid-Liquid Separation Systems

Solid-liquid separation represents a critical component of wastewater treatment, encompassing technologies that remove suspended solids, clarify treated effluent, and dewater sludge for disposal. Effective separation improves downstream process efficiency, ensures compliance with discharge limits, and reduces waste handling costs.

Multiple separation technologies are employed throughout treatment plants, each optimized for specific applications and solids characteristics. Primary clarification removes settleable solids before biological treatment. Secondary clarifiers separate biomass from treated effluent. Tertiary filtration polishes final effluent to meet stringent quality standards. Sludge dewatering reduces volumes for economical disposal or beneficial reuse.

Spans Envirotech provides comprehensive solid-liquid separation solutions including clarifiers, dissolved air flotation (DAF) units, multimedia filters, centrifuges, belt filter presses, and screw presses. Our integrated approach ensures optimal performance across all separation stages, maximizing water recovery, minimizing waste, and reducing operating costs.

Dissolved Air Flotation (DAF) is a key technology for primary separation of lighter impurities — oils, greases, fats, and fine suspended solids — that do not settle readily by gravity. In DAF, pressurized water supersaturated with dissolved air is released into the flotation tank, generating millions of micro-bubbles that attach to the target particles and reduce their effective density, causing them to float to the surface for skimming. DAF units are available in rectangular configurations with mild steel, epoxy-painted, or stainless steel 304 construction to suit the corrosivity of the wastewater. They deliver excellent laminar flow conditions that maximize separation efficiency and are particularly effective for pre-treating high-fat, high-oil effluents from food, dairy, slaughterhouse, and vegetable oil processing before biological treatment.