Fluorescent Characteristics and Metal Binding Properties of Different Molecular Weight Fractions in Stratified Extracellular Polymeric Substances of Activated Sludge

The combination of heavy metals and extracellular polymeric substances (EPSs) affects the distribution in microbial aggregates, soil, aquatic systems. This paper aimed to explore binding mechanisms EPSs different molecular weights activated sludge with metals. We extracted stratification components divided into five fractions weight ranges. In three-dimensional fluorescence analysis each fraction, had two peaks, peak A (representing low-excitation tryptophan) B high-excitation tryptophan), static quenching was main reason for between compounds attributable Pb2+ Cu2+. Further exploration suggested that interacted Cd2+, Pb2+, Cu2+, Zn2+ form new substances. effect highest (100 kDa–0.7 ?m) more significant, ability stable. study implies application from is promising. While effectively metals, it can also reduce volume excess sludge.