Journal Article

Mixotrophic cultivation of microalgae using industrial flue gases for biodiesel production

Kandimalla, Pooja, Vurimindi, Himabindu, Desi, Sreekanth

2016

Overview

In the present study, an attempt has been made to grow microalgae Scenedesmus quadricauda , Chlorella vulgaris and Botryococcus braunii in mixotropic cultivation mode using two different substrates, i.e. sewage and glucose as organic carbon sources along with flue gas inputs as inorganic carbon source. The experiments were carried out in 500 ml flasks with sewage and glucose-enriched media along with flue gas inputs. The composition of the flue gas was 7 % CO 2 , 210 ppm of NO x and 120 ppm of SO x . The results showed that S. quadricauda grown in glucose-enriched medium yielded higher biomass, lipid and fatty acid methyl esters (FAME) (biodiesel) yields of 2.6, 0.63 and 0.3 g/L, respectively. Whereas with sewage, the biomass, lipid and FAME yields of S. quadricauda were 1.9, 0.46, and 0.21 g/L, respectively. The other two species showed closer results as well. The glucose utilization was measured in terms of Chemical Oxygen Demand (COD) reduction, which was up to 93.75 % by S. quadricauda in the glucose-flue gas medium. In the sewage-flue gas medium, the COD removal was achieved up to 92 % by S. quadricauda . The other nutrients and pollutants from the sewage were removed up to 75 % on an average by the same. Concerning the flue gas treatment studies, S. quadricauda could remove CO 2 up to 85 % from the flue gas when grown in glucose medium and 81 % when grown in sewage. The SO x and NO x concentrations were reduced up to 50 and 62 %, respectively, by S. quadricauda in glucose-flue gas medium. Whereas, in the sewage-flue gas medium, the SO x and NO x concentrations were reduced up to 45 and 50 %, respectively, by the same. The other two species were equally efficient however with little less significant yields and removal percentages. This study laid emphasis on comparing the feasibility in utilization of readily available carbon sources like glucose and inexpensive leftover carbon sources like sewage by microalgae to generate energy coupled with economical remediation of waste. Therefore on an industrial scale, the sewage is more preferable. Because the results obtained in the laboratory demonstrated both sewage and glucose-enriched nutrient medium are equally efficient for algae cultivation with just a slight difference. Essentially, the sewage is cost effective and easily available in large quantities compared to glucose.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V
• Subject: Algae / Aquatic microorganisms / Aquatic Pollution / Atmospheric Protection/Air Quality Control/Air Pollution / Biodegradable materials / biodiesel / Biodiesel fuels / Biofuels / Biomass / Botryococcus braunii / Carbon / Carbon dioxide / Carbon sources / Chemical oxygen demand / Chlorella vulgaris / Chlorophyta - drug effects / Chlorophyta - metabolism / cost effectiveness / Cultivation / culture flasks / Diesel / Earth and Environmental Science / Ecotoxicology / Emissions / energy / Enrichment media / Environment / Environmental Chemistry / Environmental Health / Environmental Restoration and Remediation / Esters / Experiments / Fatty acid methyl esters / Fatty Acids / Feasibility studies / Flue gas / Fossil fuels / fuel production / Gases / Gases - chemistry / Gases - metabolism / Glucose / Glucose - metabolism / Glucose - pharmacology / Industrial plant emissions / Industrial Waste / Inorganic carbon / Laboratories / Lipids / Microalgae / Nitrogen / nitrogen oxides / Nutrients / Organic carbon / Pipelines / Pollutants / Pollution Control Technologies and Alternate Energy Options / Raw materials / remediation / Scenedesmus quadricauda / Sewage / Sewer gas / Statistical analysis / Waste Water Technology / Water Management / Water Pollution Control