Performance Evaluation of Ceramic Membrane Based Process for Microalgal Biomass Harvesting: Analyzing the Effect of Membrane Pore Sizes, Process Optimization and Fouling Behavior

Microalgal biofuel emerges as a potential resource of renewable energy in view of global energy demand and increasing greenhouse gases. However, substantial challenges of efficient up-concentrating of biomass act as a bottleneck in large scale production of biofuel. The study is aimed towards unravelling the obstacles encountered during dewatering of biomass from mixed-microalgae consortia using ceramic membrane based process with varying pore sizes in the microfiltration (MF) and ultrafiltration (UF) range. For clay and alumina based MF membrane, 1.2 µm pore size (average) and for alumina supported nano-alumina coated UF membrane, ∼0.01 µm pore size (average) was used. The effect of various recirculation parameters was studied for process optimization. Resistance-in-series model was employed for analyzing fouling behavior of the membranes. MF membrane was observed to have better harvesting efficiency than the UF counterpart in terms of productivity (124.41). Optimum permeate flux of microalgal suspension was found to be 315.29 L.m−2.h−1 for MF membrane. Regeneration of membranes by air assisted backpulsing process showed up to 97.71% of flux recovery for MF membrane. Volume reduction factor/ membrane area (371) was found to be considerably high compared to various reported studies. The study highlighted efficient harvesting of microalgae using indigenously developed ceramic MF membrane integrated filtration towards cost-effective production of biofuel. GRAPHICAL ABSTRACT