Recovery of Bovine Serum Albumin from Wastewater Using a Cellulose Blend Membrane Derived from Chinese Herbal Medicine Residues

Rhodamnia rubescens herbal residue is harmful to air and water; how to realize harmlessness and achieve high value-added utilization of this Chinese medicine residue waste resource remains a considerable challenge. In this study, microcrystalline cellulose (MCC) was prepared by alkali extraction and acid hydrolysis successively from R. rubescens residues, followed by blending with jute MCC as an auxiliary component; then, a blend membrane was successfully prepared using phase transfer method. The structure and morphology of the blend membrane were analyzed by FTIR and SEM; then, its thermal stability, chemical stability, mechanical properties, optical transmittance, and separation performance for bovine serum albumin (BSA) in simulated wastewater were further tested. The results demonstrated that the tensile strength of the blend cellulose membrane increased by 2.11 times, elongation at break increases by 0.62 times respectively compared with the pure R. rubescens cellulose membrane. Moreover, the rejection rate for BSA generally maintained over 93%, indicating a better performance in BSA recovery. This research demonstrates the potential of utilizing R. rubescens herbal residue in the production of high-value blend membranes with enhanced properties and significant environmental benefits.