Recovery of dehydrated aerobic granules: A comparison

Dehydrated aerobic granules, if can be sufficiently recovered without significant loss of structural stability and biological activities, presents a promising long-time storage option in practical use. This study dehydrated aerobic granules by six protocols: air drying at 25 or 50 degrees C, freeze-dry, acetone or ethanol dehydration, and microwave heating, and then recovered them in liquid medium, with the measured characteristics being reported. The granule stability has no correlation with measured settleability, hydrophobicity or extracellular polymeric substances compositions; instead, is correlated with the functional strains presented in the recovered granules. Air dry dehydration minimally damage the functional strains including genus Brevundimonas and genus Comamonas and markedly deteriorated structural breaker such as Acinetobacter of Moraxellaceae to lead to stable and tough recovered granules.