Characterization of antibiotic mycelial residue (AMR) dewatering performance with microwave treatment

•Microwave irradiation influenced the dewaterability of antibiotic mycelial residual.•Capillary suction time and water content of cake behaved differently.•Bound water in matrix was not destroyed after microwave irradiation.•Polymers and particle size distributions related to the dewaterability.•The air-drying process of the treated cake slowed after microwave treatment.

This study characterizes antibiotic mycelial residue (AMR) dewaterability with microwave (MW) treatment. Capillary suction time (CST) and the water content (WC) of AMR cake were used to evaluate AMR dewaterability. A thermogravimetric analysis and investigation of changes in AMR physical characteristics (e.g., extracellular polymeric substances (EPS) and particle size) were conducted to interpret AMR dewaterability variations. The results indicate that MW irradiation heavily influences the release of polymers and AMR particle size, which are significantly related to AMR dewaterability, e.g., the correlations between CST and EPS/dp90 are 0.95 and 0.99, respectively. Additionally, bound water in matrix was not destroyed after MW irradiation, which also affected the dewaterability. CST measurements initially decreased and later increased, while WC values substantially decreased following MW treatment. The different patterns indicate that one measurement index cannot provide an overall explanation for AMR dewaterability.

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