1*Department of Chemical Engineering, Vel Tech High Tech Dr. Rangarajan Dr. Sakunthala Engineering College, Chennai – 600062, India
Email: nancyphd2413@gmail.com
Phone: +91 9524898827
2Assistant Professor, Department of Electronics and Communication Engineering, Vel Tech Multi Tech Dr. Rangarajan, Dr. Sakunthala Engineering College, Chennai-600062, India
3Assistant Professor, Department of Petroleum Engineering, JCT College of Engineering and Technology, Coimbatore-641105, India
Dairy wastewater, characterized by high organic load, nutrients, and complex biomolecules such as proteins, lactose, and lipids, poses significant environmental challenges due to its recalcitrance to conventional biological treatment. Advanced oxidation processes particularly photocatalysis offer a promising route for effective remediation, yet their practical deployment hinges on the development of efficient, visible-light-responsive, and eco-friendly photocatalysts. In this context, carbon quantum dots (CQDs) derived from Spirulina platensis, a nitrogen-rich cyanobacterium, have emerged as a sustainable nanomaterial with intrinsic heteroatom doping, tunable optoelectronic properties, and excellent photocatalytic activity under solar irradiation. This review critically examines recent advances in the synthesis, functionalization, and application of Spirulina-derived CQDs for the photocatalytic treatment of dairy wastewater. We elucidate structure–property–performance relationships, degradation mechanisms of key dairy pollutants, and the role of reactive oxygen species in mineralization pathways. Special attention is given to hybrid systems such as CQD-based heterojunctions and photoelectrocatalytic configurations that enhance charge separation and process efficiency. Furthermore, we evaluate the scalability, economic viability, and environmental footprint of these bio-derived nanocatalysts through techno-economic and life-cycle perspectives. By bridging materials innovation with real-world wastewater complexity, this review identifies critical knowledge gaps and proposes a multidisciplinary roadmap toward pilot-scale implementation. Ultimately, Spirulina-derived CQDs exemplify a circular bioeconomy approach, transforming algal biomass into high-value photocatalysts for sustainable water purification aligning environmental remediation with renewable resource utilization. Highlighting their optoelectronic properties and potential for smart sensing-integrated remediation systems, this work aims to inspire next-generation research at the intersection of green nanotechnology, electrochemical engineering, and industrial wastewater management.
Keywords: Spirulina-derived carbon quantum dots, photocatalysis, dairy wastewater remediation, biomass valorization, advanced oxidation processes, sustainable nanomaterials.
How to cite this article: Flora RMN, Johnson I, Harini S, Sakthipriya R, Devimari B, Girija M, Pavithra S. Spirulina-derived carbon quantum dots for photocatalytic remediation of dairy wastewater: advances, mechanisms, and optoelectronic prospects. Int J Drug Deliv Technol. 2026;16(6s): 433-452; DOI: 10.25258/ijddt.16.6s.68
Source of support: None
Conflict of interest: None