Strengthening mass transfer with the Tesla-valve baffles to increase the biomass yield of Arthrospira platensis in a column photobioreactor

The microalgae Chlorella sp. grows well in POME medium sparged with a mixture of carbon dioxide (CO2) gas and air under 10,000 lx of lighting. The percentage of CO2 in the mixture, and the flow rate of the mixture (representing agitation) have important effects on the microalgae biomass yield. However, the percentage recovery of CO2 as microalgae biomass was very low in all cases, indicating that most of the sparged CO2 did not dissolve in the POME and was not sequestered by the microalgae but has in fact escaped with the bubbles into the head-space and out into the atmosphere. This result indicates that in order to increase the percentage of CO2 recovered, the area of improvement is mainly in the mass transfer of CO2 from the gas phase into the liquid phase. To ensure that dissolved CO2 does not re-form bubbles, the mass transfer has to be demand-driven, where the rate of uptake of dissolved CO2 by the microalgae has to be higher than the rate of mass transfer of CO2 from gas phase into the liquid medium.

Download Full-text

Cultivation of an Arthrospira platensis with digested piggery wastewater

Water Science & Technology ◽

10.2166/wst.2015.353 ◽

2015 ◽

Vol 72 (10) ◽

pp. 1774-1779 ◽

Cited By ~ 1

Author(s):

Rui Liu ◽

Qingqing Guo ◽

Wei Zheng ◽

Lüjun Chen ◽

Jinfei Luo

Keyword(s):

Protein Content ◽

Crude Protein ◽

Biomass Yield ◽

Nitrate Nitrogen ◽

Animal Feed ◽

Continuous Cultivation ◽

Arthrospira Platensis ◽

Ammonium Nitrogen ◽

Piggery Wastewater ◽

Digested Piggery Wastewater

An Arthrospira platensis strain ZJWST-S1 was isolated in Jiaxing City, China, which proved able to proliferate quickly in undiluted digested piggery wastewater (DPW), and the protein content in the algal biomass was high. Single factor experiments showed that the strain was able to quickly grow in a Zarrouk medium as the dosage of sodium bicarbonate, nitrate-nitrogen and phosphate-phosphorus was not less than 4.0 mg·L–1, 40 mg·L–1 and 10 mg·L–1, respectively. No growth inhibition was observed when the culturing medium contained nitrite nitrogen of 0–120 mg·L–1 and ammonium nitrogen of below 20 mg·L–1. Five runs of semi-continuous cultivation with DPW as the culturing medium in a 250 L raceway pond showed that the biomass yield in a 9-day semi-continuous culturing was up to 45.2–64.7 g·m–2·d–1, higher than the yields obtained by other researchers, and the crude protein content in biomass was over 50%, meeting the national animal feed grade standard. Total nitrogen (TN) and total phosphorus (TP) were removed from DPW at a rate of 10.9–14.0 mg·L–1·d–1 and 1.3–1.8 mg·L–1·d–1, respectively. The mass balance revealed that 80–93% of TN and 84–98% of TP reduced from DPW were converted to A. platensis biomass.

Download Full-text

Effects on C-phycocyanin content of Arthrospira (Spirulina) platensis of culture medium containing geothermal water.

Natural Science and Discovery ◽

10.20863/nsd.v4i3.61 ◽

2021 ◽

Vol 4 (3) ◽

pp. 16-20

Author(s):

Sibel Bayıl Oğuzkan ◽

Betül Kut Güroy

Keyword(s):

Culture Medium ◽

Biomass Yield ◽

Algal Growth ◽

Arthrospira Platensis ◽

Geothermal Water ◽

Control Group ◽

Water Medium ◽

Distilled Water ◽

Freeze Dried ◽

Experimental Group

This research aimed to compare effects on product quality and algal growth of inoculation ratio of Arthrospira platensis in the culture medium containing 20% geothermal water. A. platensis was inoculated at the ratio of 1/6, 1/10, and 1/20 of nutrient medium volume (2500 mL). The experiment medium was prepared with 20% geothermal water and 80% distilled water. Schlösser medium, 100% geothermal water medium, and 100% distilled water were used as the control group. At the end of the experiment, Spirulina biomass was obtained by filtration through 80-micron plankton cloth and freeze-dried at -60 °C. Increasing inoculation density shortened the culture time and increased the growth rate compared to the other groups. The best growth among the experimental groups was obtained in a 1/6 ratio inoculated Spirulina group in a 20% geothermal water medium. Among the experimental groups, dry biomass was obtained in the Spirulina group inoculated at 1/6 in only 20% geothermal water medium. The optical density value was 0.989 (A750), and the biomass yield was 0.476 g/L in the experimental group, the highest among the Schlösser groups was 1.259 (A750), and the biomass yield was 0.928 g/L. The most efficient growth and phycocyanin content was determined in the 1/6 inoculated groups. The phycocyanin content in the experimental group was found in 22.49%, and the purity rate was 2.24. In control groups, 3.73 purity and 28.62% phycocyanin were determined in the Schlösser medium. While 48.42% protein was detected in the geothermal water group, 61.64% was obtained with the Schlösser medium.

Download Full-text