Chlorella vulgaris (SAG 211-12) biofilm formation capacity and proposal of a rotating flat plate photobioreactor for more sustainable biomass production

Abstract

Difficulties and cost of suspended microalgal biomass harvest and processing can be overcome by cultivating microalgae as biofilms. In the present work, a new photoautotrophic biofilm photobioreactor, the rotating flat plate photobioreactor (RFPPB), was developed aiming at a costeffective production of Chlorella vulgaris (SAG 211-12), a strain not frequently referred in the literature but promising for biofuel production. Protocols were developed for evaluating initial adhesion to different materials and testing the conditions for biofilm formation. Polyvinyl chloride substrate promoted higher adhesion and biofilm production, followed by polypropylene, polyethylene, and stainless steel. The new RFPPB was tested, aiming at optimizing incident light utilization, minimizing footprint area and simplifying biomass harvesting. Tests show that the photobioreactor is robust, promotes biofilm development, and has simple operation, small footprint, and easy biomass harvest. Biomass production (dry weight) under non-optimized conditions was 3.35 g m −2 , and areal productivity was 2.99 g m −2 day −1. Lipid content was 10.3% (dw), with high PUFA content. These results are promising and can be improved by optimizing some operational parameters, together with evaluation of long-term photobioreactor maximum productivity.

Innovative Wastewater Treatment Technologies — The INNOQUA Project

“…Various supporting matrices have been trialled for algal biofilm wastewater treatment processes - Adey et al (1993) reported highest microalgae productivity (15-27g/m 2 .d) when treating agricultural run-off wastewater with biomass attached to plastic screens -while Zhuang et al (2018) found that cotton, polycarbonate and cellulose acetate were the most commonly used supports. Melo et al (2018) tested borosilicate glass, polyurethane foam, polyvinyl chloride, stainless steel, polyethylene and polypropylene, reporting that PVC was the most appropriate for culturing C. vulgaris on a rotating flat plate photobioreactor (RFPPB).…”

Effects of Ultrasonic and Microwave Pretreatment on Lipid Extraction of Microalgae and Methane Production from the Residual Extracted Biomass

“…Pasteurization of the reactors was carried out using a Tuttnauer 2840EL-D autoclave (15 min, 121°C). The culture medium was the SAG medium dedicated to the particular species of algae, excluding nitrogen compounds [33,34]. In order to obtain high lipid productivity, a nitrogen regime was used in accordance with the literature [35,36].…”

Surface cleaning and sample carrier for complementary high-resolution imaging techniques

“…The efficiency of UV-ozone treatment to improve the wettability of polymers was recently also reported for the application of PMMA polymer in chip fabrication. 17 Nevertheless, the severe damages that UV light can cause to PMMAs [40][41][42] were neither taken into consideration nor monitored. Here, the treatment of an aged polymer layer with direct UV irradiation for 2 min in the PULC-120 without the reaction cell did not improve the hydrophilicity.…”