Molecular dynamic modeling of EPS and inorganic/organic flocculants during sludge dual conditioning

Extracellular polymeric substances (EPS) are the key components determining the dewatering behavior of wastewater sludge. However, current technical optimization of sludge conditioning for dewatering is limited by the poor understanding of the conditioner-EPS interactions at molecular levels. Herein, a combination of molecular dynamic (MD) simulations, dewaterability assessment and EPS characterization was used to reveal the sludge dewatering mechanisms using dual conditioning processes (prevalent inorganic (poly aluminum chloride (PAC)) and organic (poly dimethyl diallyl ammonium chloride (PDDA)). Results suggested that PAC and PDDA bridged the biopolymers mainly through electrostatic interactions, promoting the agglomeration of biopolymers