Feasibility analysis of continuous extraction of biomaterials from flocculant sludge and potential applications in the fire protection field.

The sludge contains many high-value biological materials. However, current extraction methods focus only on individual materials, neglecting the further extraction potential of the residual after extraction. This study used continuous extraction to extract extracellular polymeric substances (EPS) and proteins (PN) from sludge, verified the flame retardancy of EPS and the foaming properties of PN and finally analyzed the economic feasibility of continuous extraction.

The feasibility and applicability of sequential extraction of high value-added biogenic materials from sewage sludge.

The sequential extraction routes of biogenic materials from sewage sludge (SS) were investigated. Physical methods (ultrasound, heating) and chemical methods (sodium hydroxide, sodium carbonate) were used to extract extracellular polymeric substances (EPS) and alginate-like extracellular polymers (ALEs) from SS. The residues after extraction were further subjected to physical methods (heating) and chemical methods (sulfuric acid, sodium hydroxide) for protein extraction.