Integrated Multi-Technology Framework for Algal Wastewater Treatment: A Comprehensive Review of Biofilm Reactors, Nano-Enhancement, AI Optimization, and 3D-Printed Architectures

Abstract

Conventional wastewater treatment methods typically achieve 70–90% removal efficiency for organic pollutants. However, the global wastewater crisis—with 80% of wastewater discharged untreated—demands innovative solutions to overcome persistent challenges in nutrient removal and resource recovery. This review presents the first systematic analysis of technology integration strategies for algal wastewater treatment, examining synergistic combinations of biofilm reactors, nano-enhancement, artificial intelligence, and 3D printing technologies. Individual technologies demonstrate distinct performance characteristics: algal biofilm reactors achieve 60–90% removal efficiency with biomass productivity up to 50 g/m2/day; nano-enhanced systems reach 70–99% pollutant removal; AI optimization provides 15–35% efficiency improvements with 25–35% energy reductions; and 3D-printed architectures achieve 70–90% removal efficiency. The novel integration framework reveals that technology combinations achieve 85–95% overall efficiency compared to 60–80% for individual approaches. Critical challenges include nanomaterial toxicity (silver nanoparticles effective at 10 mg/L), high costs (U.S. Dollar (USD) 50–300 per m2 for 3D components, USD 1500+ per kg for nanomaterials), and limited technological maturity (TRL 4–5 for AI and 3D printing). Priority development needs include standardized evaluation metrics, comprehensive risk assessment, and economic optimization strategies. The integration framework provides technology selection guidance based on pollutant characteristics and operational constraints, while implementation strategies address regional adaptation requirements. Findings support integrated algal systems’ potential for superior treatment performance and circular economy contributions through resource recovery.

Topics & Concepts