Nutrient removal and microalgal biomass production from different anaerobic digestion effluents with Chlorella species

Abstract

Potential of microalgal cultivation as an alternative approach to the treatment of anaerobic digestion (AD) effluents was examined using two representative Chlorella species, Chlorella vulgaris (CV) and Chlorella protothecoides (CP). Both species effectively removed NH 4 + -N from the AD effluents from four digesters treating different wastes under different operating conditions. In all experimental cultures on the AD effluents, NH 4 + -N (initial concentration, 40 mg/L) was completely removed within 10 days without residual NO 3 − -N or NO 2 − -N in batch mode. Compared to CP, CV showed greater biomass and lipid yields (advantageous for biodiesel production), regardless of the media used. Prolonged nitrogen starvation significantly increased the lipid accumulation in all cultures on the AD effluents, and the effect was more pronounced in the CV than in the CP cultures. On the other hand, compared to CV, CP showed significantly faster settling (advantageous for biomass harvesting) in all media. Our results suggest that the Chlorella cultivation on AD effluents under non-sterile, mixed-culture conditions may provide a viable way to manage and valorize the problematic effluents. Diverse bacteria derived from the AD effluents co-existed and presumably interacted with the Chlorella species in the cultures.

In-Situ and Ex-Situ Phycoremediation Competence of Innate Scenedesmus Sp. On Polluted River Water

“…The IR spectra of polluted water treated biomass represented an unstable of the peaks at 698 cm -1 and 690 cm -1 . Similarly, Yu et al (2019) reported the FTIR transmittance of dried biomass of Scenedesmus sp. as an aliphatic character at 400-800, phenols, and alcoholic groups at 1,000-1,400, carboxyl group at 1,500-1,700 cm -1 , hydroxyl group: 3,200-3,400 cm -1 .…”

Effects of Liquid Digestate Treatment on Sustainable Microalgae Biomass Production

“…Currently, the use of liquid digestate as a substrate for microalgae growth medium has attracted much attention as a wastewater treatment technology with the simultaneous sustainable microalgae biomass feedstock production [10][11][12][13]. Microalgae have the ability to efficiently utilize nutrients from liquid fraction of digestate, and mixotrophic cultivation may enhance inorganic and organic carbon removal, while providing biomass for bioenergy applications [8].…”

“…Thus, there is a need for overcoming the limitations to upgrade algal fuel production from pilot to commercial level. A major challenge for the effective microalgae production is the liquid digestate treatment to control the high turbidity of digestate, high and unbalanced nutrients concentrations, content of competing microorganisms, and the potential toxicity caused by organic compounds and ammonia concentrations [7,10,15].…”

In situ3D comparison ofChlorella pyrenoidosawith nuclear-irradiated mutagenic strains by using focused ion beam milling and cryo-electron tomography

“…In theory, one Chlorella cell can reproduce 100 million cells within 10 days, nearly equally to the speed of nuclear fission (2). Besides, C. pyrenoidosa is increasingly used for industrial and biomedical applications, such as CO2 flue gas fixation (3,4), biodiesel production (5,6), high-value nutritional extracts (7)(8)(9)(10), and anti-inflammatory products (1, 11). Moreover, nuclear radiation (12)(13)(14) is commonly used in full-scale bioreactors (15) to realize specified functions, such as increasing removal of pollutants from wastewater (16), higher CO2 concentration fixation (17), and increased biodiesel production (18).…”