Enhancing Sludge Dewatering and Filtrate Carbon Source Recovery via Typical Bioenzymatic Conditioning

• • Lysozyme conditioning reduced SRF, CST, and Wc simultaneously, whereas amylase and protease decreased Wc but increased SRF and CST by up to 45%, indicating a trade-off between cake solids and filtration rate. • • Composite lysozyme and protease with asynchronous addition (protease/amylase followed by lysozyme) achieved the lowest Wc, while simultaneous addition improved SRF and CST by over 30%, highlighting the importance of dosing order. • • All three enzymes increased filtrate SCOD by 20-35%, converting humic acid-like substances into tryptophan-like and tyrosine-like compounds, enhancing carbon bioavailability for denitrification. • • Enzyme conditioning reduced sludge particle size by 10-25%, with lysozyme decreasing viscosity and increasing hydrophobicity, whereas amylase and protease increased viscosity and hydrophilicity due to EPS disruption.