Assessment of Nutrients Recovery Capacity and Biomass Growth of Four Microalgae Species in Anaerobic Digestion Effluent

Abstract

Four microalgae species were evaluated for their bioremediation capacity of anaerobic digestion effluent (ADE) rich in ammonium nitrogen, derived from a biogas plant. Chlorella vulgaris, Chlorella sorokiniana, Desmodesmus communis and Stichococcus sp. were examined for their nutrient assimilation efficiency, biomass production and composition through their cultivation in 3.7% v/v ADE; their performance was compared with standard cultivation media which consisted in different nitrogen sources, i.e., BG-11NO3 and BG-11ΝΗ4 where N-NO3 was replaced by N-NH4. The results justified ammonium as the most preferable source of nitrogen for microalgae growth. Although Stichococcus sp. outperformed the other 3 species in N-NH4 removal efficiency both in BG-11NH4 and in 3.7% ADE (reaching up to 90.79% and 69.69% respectively), it exhibited a moderate biomass production when it was cultivated in diluted ADE corresponding to 0.59 g/L, compared to 0.89 g/L recorded by C. vulgaris and 0.7 g/L by C. sorokiniana and D. communis. Phosphorus contained in the effluent and in the control media was successfully consumed by all of the species, although its removal rate was found to be affected by the type of nitrogen source used and the particular microalgae species. The use of ADE as cultivation medium resulted in a significant increase in carbohydrates content in all investigated species.

Microalgal Growth and Nutrient Removal Efficiency in Non-Sterilised Primary Domestic Wastewater

“…in this study was higher. The different results between these studies may be attributed to several reasons such as different microalgae strains, light intensity, initial inoculum, and the carbon: nitrogen: phosphate ratios in the wastewater [58,69,70].…”

“…These results indicate the non-sterilised domestic wastewater without dilution can serve as a growth medium for H. pluvialis, Scenedesmus sp., C. aquaticum, and A. augustus. Previous studies also revealed other kinds of non-sterilised wastewater have the potential for microalgal cultivation [58]. Khatiwada et al [59] indicated that Chlorella sp.…”

Study of Chlorella sorokiniana Cultivation in an Airlift Tubular Photobioreactor Using Anaerobic Digestate Substrate

“…C. sorokiniana employed in this work isolated from the particular anaerobic digestion effluent according to the procedure described in a previous study [13]. Microalgae were cultured at 25 ± 2 • C in 2 L Erlenmeyer flasks in an incubating room under 1500 lux illumination, using a 16 h lighting period.…”

“…Furthermore, the use of anaerobic digestate as a low-cost nutrient source for microalgae growth represents a challenging approach, requiring considerable efforts for the selection of suitable microalgae strains and the implementation of appropriate operation conditions to efficiently recover nutrients and promote biomass production. In a laboratory study, Chlorella sorokiniana demonstrated superior performance in growing in diluted anaerobic digestate, showing a high nitrogen removal rate [13].…”

State of microalgae-based swine manure digestate treatment: An overview

“…There are different alternatives for the utilization of these residues, such as the generation of bioelectricity [ 9 ], fertilizers [ 10 ], animal feed [ 11 ], But there are not many studies regarding its use as a source of nutrients for the cultivation of microalgae [ 12 , 13 , 14 , 15 , 16 , 17 ], thus ignoring the high potential of this effluent since anaerobically treated animal waste contains nutrients such as N and P (NH+4, NO-3, PO3-4) which are suitable for growing alga[which represents a great opportunity as an animal feed, a source of protein or biofuel [ 14 , 15 ],. In other words, the lack of research related to the cultivation of microalgae using porcine residues, is reflected not only in the generation of a negative environmental impact, but given the inadequate and inefficient technologies, together with the low recovery and use of waste, it also causes a loss of value and competitiveness in the market.…”