Assessment of Chitosan Conditioning in a Synthetic Anaerobic Digested Sludge System

Abstract

Effects of dosage and pH in chitosan conditioning were investigated for studying the anaerobic digested sludge dewatering characteristics using a modified synthetic sludge system. A comparison was made with the conditioning results using inorganic metal cations. Capillary suction time, turbidity and filtered cake solids content were measured to assess sludge dewaterability. Floc sizes and the Fourier Transform Infrared spectrums were also examined for the conditioned sludge properties. Experimental results indicate that sludge conditioned with chitosan showed remarkable dewaterability with close resemblance to real sludge system. A strong correlation between floc size and dewaterability was observed with increasing chitosan dosage. The optimum dewaterability was found in the acidic region. The synthetic sludge conditioned with chitosan showed comparable dewaterability with the one conditioned with trivalent cation. This proposed synthetic sludge behaves similar to a typical anaerobic digested sludge when conditioned with chitosan.