Plume Entrainment

A bubble plume does its work by entrainment: rising bubbles drag a column of water upward, drawing in surrounding water along the plume’s length. The entrainment coefficient sets how much water is circulated per unit air — the quantity that governs destratification and oxygen distribution.

Plume entrainment — how a rising bubble plume drags surrounding water upward, the mechanism behind aeration-driven circulation.

Reynolds & Bauhm sizes reservoir aeration from measured oxygen demand and transfer fundamentals — selecting destratification or hypolimnetic oxygenation and the right device, with plume and diffuser design proven against the reservoir's depth and stratification.

Reservoir aeration and oxygenation manage the consequences of thermal stratification, where a warm surface layer seals a cold, oxygen-starved hypolimnion beneath a thermocline. Once isolated, the hypolimnion's oxygen is consumed by sediment demand and cannot be replaced from the atmosphere, triggering the release of iron, manganese, ammonia and phosphorus from the bed that degrade raw-water quality — the problem aeration exists to solve.

Two strategies address it. Destratification mixes the whole water column to prevent or break stratification, re-oxygenating the bottom by circulation; hypolimnetic aeration or oxygenation instead adds oxygen to the deep layer while deliberately preserving the cold, stratified structure that downstream abstraction may rely on. The choice depends on objectives, depth and the abstraction regime.