High yield cultivation of marine macroalga Ulva lactuca in a multi-tubular airlift photobioreactor: A scalable model for quality feedstock. (20th December 2021)

• Record Type: Journal Article
• Authors: Savvashe, Prashant; Mhatre-Naik, Akanksha; Pillai, Gayatri; Palkar, Juilee; Sathe, Mayur; Pandit, Reena; Reddy, C.R.K.; Lali, Arvind M.
• Is Part Of: Journal of cleaner production. Volume 329(2021)
• Publication Date: 2021-12-20
• Subjects: Airlift photobioreactor -- Coastal agronomy -- Macroalgae -- Onshore cultivation -- Renewable feedstock -- Ulva lactuca; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2021.129746
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Conventional off-shore and on-shore cultivation methods for marine macroalgae are both inadequate to pitch macroalgae as scalable renewable feedstock that can be grown across all coastal locations. With on-shore cultivation likely to be sustainable and preferred over eco-damaging open seas cultivation, new reactor systems need to be developed for on-shore cultivation of seaweeds at scale. The present work is an attempt to use the indigenously designed vertical multi-tubular air-lift photobioreactor system to grow Ulva lactuca through the entire year under natural conditions. Optimized operation of the 1000 L photobioreactor assembly demonstrated a year-round averaged productivity of 0.87 kg m −2 .d −1 (fresh weight) implying 1800 ton.ha −1 .y −1 feedstock production. Carbon dioxide supplementation (5%), optimized circulation velocity (0.25–0.35 m/s), and managing nitrogen supply (17 ppm), under natural light intensities (500–1400 μmol m −2 .s −1 ) provided a year-round sustained and continuous production of Ulva lactuca biomass. The photobioreactor system designed as a modular, linearly scalable, and resilient system operates with low land and water footprints, and gives a multi-fold increase in renewable feedstock production compared to the conventional sea-based and other on-shore tank-based practices. For the video summary of this article, see the file in the supplemental data. Graphical abstract: Image 1 Highlights: Cultivation of Ulva lactuca biomass using airlift photobioreactors. Demonstration of year-round outdoor cultivation of marine feedstock. Continuous and consistent supply of food-grade Ulva lactuca biomass. Demonstration of multi-fold improvement in aerial biomass production. Proof of concept promoting and supporting coastal agronomy.