Attachment of microalgae-bacteria consortium on natural adsorbent for wastewater treatment

This study investigates the use of different natural adsorbents for immobilizing microalgae- bacteria consortium to improve wastewater treatment efficacy. Two microalgae strains, Chlorella sp. PL1 and microalgae PL2, along with a bacterial strain Paracoccus sp. B4(L2), were isolated from an indigenous population. Various natural adsorbents, including wood chips, sponge gourd, corn cobs, and neem leaves, were evaluated for their adsorption efficacy. Among these, neem leaves showed the highest adsorption potential, fostering efficient biofilm formation of the microalgae-bacteria consortium. The biomass adsorbed on neem leaves exhibited high carbohydrate (539.4 mg g−1), lipid (327.5 mg g−1), protein (990 mg g−1), and chlorophyll (32.76 mg g−1) content. Wastewater treatment comparative study was conducted using free cells and cells immobilized on neem leaves of microalgae-bacteria consortium. Immobilized cells demonstrated higher reduction in biochemical oxygen demand (BOD-75%), chemical oxygen demand (COD-72%), and other parameters as compared to free cell. The study highlights the potential of neem leaves as an effective natural adsorbent adsorbed on microalgae-bacteria consortium for enhanced microbial wastewater treatment. Natural adsorbents (wood chips, sponge gourd, corn cobs, and neem leaves) were evaluated for immobilizing a microalgae-bacteria consortium. Neem leaves exhibited the highest adsorption capacity and supported efficient biofilm formation. Immobilized consortium achieved 75% BOD and 72% COD removal. Neem leaves offer a low-cost, eco-friendly wastewater treatment approach.