An orbital shaker operated at orbiting speeds between 150 and 250 rpm with flasks of, for example, 2000 ml capacity, can be used to satisfy the oxygen demand for the sludge and overcome difficulties with chemicals that produce excessive foam, are volatile and therefore lost, or are difficult to disperse when aerated by air sparging.
La perte de résidus solides de la boue dans le mélange d'essai se traduit par des taux de respiration artificiellement réduits, susceptibles d'être faussement interprétés comme l'effet d'une inhibition.