Correlation between electron acceptor-donor capacity of organic components and sludge dewatering performance during pre-oxidation

Title

Correlation between electron acceptor-donor capacity of organic components and sludge dewatering performance during pre-oxidation

Speaker

Yizhang Jiang (PhD Student in CEE)

Time

Monday, November 18, 2024, 16:00-17:00 (Beijing time) or 10:00-11:00 (Israel time)

Zoom Link and Code

https://gtiit.zoom.us/j/99531878300?pwd=k3wn734ZTelu7bg3h4Xp2l0ZxCV6Yu.1

246114

Abstract

Currently, pre-oxidation has been widely applied as an effective method to improve sludge dewatering performance. However, both insufficient and excessive degrees of pre-oxidation lead to poor dewatering performance. An evaluation of a proper sludge pre-oxidation degree is crucial for optimizing the type and dose of oxidants in sludge dewatering. This study proposed a parameter, the electron donor-acceptor capacity of organic components in soluble extracellular polymeric substances, to correlate with parameters reflecting sludge dewatering performance and other hydrophilic organic components affecting sludge dewatering. The electron acceptor capacity in soluble extracellular polymeric substances (S-EAC) and electron donor capacity in soluble extracellular polymeric substances (S-EDC) exhibited strong correlations with capillary suction time (S-EAC: correlation coefficient (r) = –0.988, probability (p) < 0.01; S-EDC: r = 0.968, p < 0.01), and specific resistance to filtration (S-EAC: r = –0.875, p < 0.05; S-EDC: r = 0.818, p < 0.05). The structure properties (mainly aromatic groups, the O10-O12 species distribution within the CHONS compound, tryptophan-like proteins, humic acid-like substances, protein secondary structure of β-sheet, sulfur-containing organic matter, and carbon saturation) rather than the total concentration of organic components significantly affected the electron transfer properties of organic components. A multiple linear regression model was developed to further reflect the linear relationship between the S-EAC and S-EDC values and the key factors affecting sludge dewatering performance. Besides anaerobic digested sludge of food waste, the feasibility of this method in alkaline pretreated waste activated sludge was confirmed. This study demonstrated the potential of using the S-EAC and S-EDC values as an evaluation tool for the pre-oxidation degree of sludge dewatering.