Beyond the Bubble: Rethinking High-Rate Solids Separation with Gas Energy Mixing (GEM®) Technology
Wednesday, September 30, 2026 9:00 AM to 9:30 AM · 30 min. (US/Central)
New Orleans Convention Center
Technology Spotlight
Hall H Booth 7249
Information
Overview & Objectives
Conventional dissolved air flotation (DAF) generates microbubbles (20–100 µm) via pressure saturation of a recycled stream, limiting air-to-water ratios to ~0.15:1. Bubble-particle contact occurs in quiescent tanks with hydraulic loading rates (HLR) of only 5–50 m/h, requiring large footprints. This presentation examines the Gas Energy Mixing - GEM® System - as an alternative hydrodynamic flotation architecture. The objective is to provide quantitative, physics-based criteria - bubble size distribution, centrifugal acceleration, and floc porosity - for evaluating high-rate solids separation technologies. Unlike DAF, GEM® System operates at air-to-water ratios exceeding 0.5:1 via direct gas injection. Attendees will learn why conventional DAF underperforms with emulsions and high-solids wastewaters, and how centrifugal flotation addresses these fundamental limitations.
Methodology & Hydrodynamic Design
The GEM® System replaces the saturator and recycle loop with a Liquid Cyclone Particle Positioner (LCPP) and liquid-solid-gas mixer (LSGM) heads. Wastewater enters tangentially, generating centrifugal accelerations of 25–1,000 Gs. Gas is injected directly and sheared within the LCPP, producing bubbles of 15–40 µm. Unlike DAF, bubble nucleation occurs in situ during chemical conditioning. The LSGM head allows sequential mixing energies: high energy for coagulants, then low energy for ultrahigh-molecular-weight flocculants (>5–7 million D). This dual-polymer sequence, combined with centrifugal vortex mixing, yields flocs up to 10 cm in diameter with entrained air. Hydraulic retention time in the LCPP is milliseconds; flocculation occurs in seconds, not minutes. The cavitation plate downstream nucleates dissolved gases directly within floc structures - a mechanism absent in conventional DAF. The centrifugal field also classifies particles by density, accelerating hydrophobic contaminants toward the gas-liquid interface while dense grit migrates outward for removal.
Field Findings & Performance Data
Data from more than 1,000 installations document TSS and FOG removal >98%. At a seafood processor with 28,000 ppm TSS and 62,000 ppm COD, effluent TSS fell to 150 ppm and COD to 12,000 ppm. Float sludge solids content ranges from 10–30%, versus 1–6% for conventional DAF. HLR for GEM® System ranges from 20–350 m/h, reducing footprint to 10–20% of conventional DAF. The system responds to influent changes in seconds, enabling turbidity-triggered chemical dosage control. Unlike ASH systems, GEM® System eliminates the vortex finder, avoiding dilution of recovered sludge. In rendering plant applications with 25,000 ppm TSS, effluent dropped below 80 ppm while producing a float sludge of 25% solids, directly reducing hauling costs by 70%.
Significance & Learning Value for Attendees
Attendees will learn to: (1) distinguish flotation technologies by bubble generation mechanism and bubble size distribution (GEM® System: 15–40 µm; DAF: 20–50 µm; ASH: 80–200 µm); (2) identify design parameters driving separation - HLR, centrifugal Gs, and sludge solids loading; and (3) evaluate retrofit pathways, including piloting and integration with membrane or biological trains. A comparative framework enables technology selection based on influent TSS concentration, footprint, and sludge disposal costs. Attendees will leave with a decision matrix they can apply immediately to their own facilities.
Conventional dissolved air flotation (DAF) generates microbubbles (20–100 µm) via pressure saturation of a recycled stream, limiting air-to-water ratios to ~0.15:1. Bubble-particle contact occurs in quiescent tanks with hydraulic loading rates (HLR) of only 5–50 m/h, requiring large footprints. This presentation examines the Gas Energy Mixing - GEM® System - as an alternative hydrodynamic flotation architecture. The objective is to provide quantitative, physics-based criteria - bubble size distribution, centrifugal acceleration, and floc porosity - for evaluating high-rate solids separation technologies. Unlike DAF, GEM® System operates at air-to-water ratios exceeding 0.5:1 via direct gas injection. Attendees will learn why conventional DAF underperforms with emulsions and high-solids wastewaters, and how centrifugal flotation addresses these fundamental limitations.
Methodology & Hydrodynamic Design
The GEM® System replaces the saturator and recycle loop with a Liquid Cyclone Particle Positioner (LCPP) and liquid-solid-gas mixer (LSGM) heads. Wastewater enters tangentially, generating centrifugal accelerations of 25–1,000 Gs. Gas is injected directly and sheared within the LCPP, producing bubbles of 15–40 µm. Unlike DAF, bubble nucleation occurs in situ during chemical conditioning. The LSGM head allows sequential mixing energies: high energy for coagulants, then low energy for ultrahigh-molecular-weight flocculants (>5–7 million D). This dual-polymer sequence, combined with centrifugal vortex mixing, yields flocs up to 10 cm in diameter with entrained air. Hydraulic retention time in the LCPP is milliseconds; flocculation occurs in seconds, not minutes. The cavitation plate downstream nucleates dissolved gases directly within floc structures - a mechanism absent in conventional DAF. The centrifugal field also classifies particles by density, accelerating hydrophobic contaminants toward the gas-liquid interface while dense grit migrates outward for removal.
Field Findings & Performance Data
Data from more than 1,000 installations document TSS and FOG removal >98%. At a seafood processor with 28,000 ppm TSS and 62,000 ppm COD, effluent TSS fell to 150 ppm and COD to 12,000 ppm. Float sludge solids content ranges from 10–30%, versus 1–6% for conventional DAF. HLR for GEM® System ranges from 20–350 m/h, reducing footprint to 10–20% of conventional DAF. The system responds to influent changes in seconds, enabling turbidity-triggered chemical dosage control. Unlike ASH systems, GEM® System eliminates the vortex finder, avoiding dilution of recovered sludge. In rendering plant applications with 25,000 ppm TSS, effluent dropped below 80 ppm while producing a float sludge of 25% solids, directly reducing hauling costs by 70%.
Significance & Learning Value for Attendees
Attendees will learn to: (1) distinguish flotation technologies by bubble generation mechanism and bubble size distribution (GEM® System: 15–40 µm; DAF: 20–50 µm; ASH: 80–200 µm); (2) identify design parameters driving separation - HLR, centrifugal Gs, and sludge solids loading; and (3) evaluate retrofit pathways, including piloting and integration with membrane or biological trains. A comparative framework enables technology selection based on influent TSS concentration, footprint, and sludge disposal costs. Attendees will leave with a decision matrix they can apply immediately to their own facilities.