CSR was obtained from a local cassava-based bioethanol factory (Tianjin, China). The sun-dried CSR was comminuted and screened to the particle size less than 0.28 mm (60 mesh). WCO was collected from a local restaurant. The WCO sample was filtered to remove the suspended waste residue and was then heated to evaporate the residual water. The WCO was stored in a sealed bottle at room temperature, and its acid value and FFA content were measured daily for 30 consecutive days until a stable equilibrium was achieved. The acid value and FFA content of the WCO were 28.05 mg KOH/g and 20 wt.%, respectively. The free fatty acid profile indicated that the WCO contained palmitic, stearic, oleic and linoleic fatty acids.