Tailored a Multiple Tandem Reaction System for Microalga Cascade Utilization

Integrating multiple systems to achieve cascade utilization of microalgae is an advanced biorefinery prospect that can better deal with biowaste disposal. Unfortunately, the current implementations have not explored an efficient and feasible route for Chlorella cascade resource utilization. Here, a multiple tandem reaction system was imaginatively constructed in this investigation for the first time to achieve efficient utilization of Chlorella at different process stages. The system consists of (i) a pigments extraction module, (ii) an anaerobic fermentation module, and (iii) an advanced oxidation processes module. Specifically, the high-valued pigments [chlorophyll (a-b)] were first extracted from Chlorella. Then, the sludge was mixed with pigment-extracted Chlorella residue for anaerobic Co-fermentation to produce methane (CH₄). Ultimately, the fermentation residue was calcined at a high temperature and doped with nonmetal (boron)-metal (cobalt) to obtain a recyclable biochar (B,Co-SBC) catalyst. The different modules work in concert with each other to maintain the stable operation of the tandem reaction system. Together, the multiple tandem reaction system proposed in this study can add a new technology library for resource utilization as well as provide a valuable reference for water remediation.