THE EFFECT OF EXTRACTION ON THE DEWATERING PROPERTIES OF PAPER SLUDGE

The dewatering of paper sludge continues to be a major problem in pulp and paper industry. In this study, the extraction of paper sludge using ethylenediamine tetraacetic acid (EDTA), sodium hydroxide, hydrochloric acid or acetic acid was examined experimentally. A compression test of paper sludge obtained after extraction was carried out. The results showed that the total solid content of dewatered cake using acetic acid as the extracting reagent was higher than that of using EDTA, hydrochloric acid or sodium hydroxide. A flocculating sedimentation of wastewater test using the squeezed filtrate after extraction was also investigated in our laboratory. The result indicated that the squeezed filtrate could act as a bioflocculant. It is expected that this paper can provide deep insights into the dewatering properties of paper sludge.