Microalgae-mediated bioremediation and valorization of cattle wastewater previously digested in a hybrid anaerobic reactor using a photobioreactor: Comparison between batch and continuous operation

Sci Total Environ. 2018 Aug 15:633:1-11. doi: 10.1016/j.scitotenv.2018.03.157. Epub 2018 Mar 20.

Abstract

Scenedesmus obliquus (ACOI 204/07) microalgae were cultivated in cattle wastewater in vertical alveolar flat panel photobioreactors, operated in batch and continuous mode, after previous digestion in a hybrid anaerobic reactor. In batch operation, removal efficiencies ranges of 65 to 70% of COD, 98 to 99% of NH4+ and 69 to 77.5% of PO4-3 after 12days were recorded. The corresponding figures for continuous flow were from 57 to 61% of COD, 94 to 96% of NH4+ and 65 to 70% of PO4-3 with mean hidraulic retention time of 12days. Higher rates of CO2 fixation (327-547mgL-1d-1) and higher biomass volumetric productivity (213-358mgL-1d-1) were obtained in batch mode. This microalgae-mediated process can be considered promising for bioremediation and valorization of effluents produced by cattle breeding yielding a protein-rich microalgal biomass that could be eventually used as cattle feed.

Keywords: CO(2) fixation; Cattle wastewater; Flat panel photobioreactor; Microalga; Nutrient removal.

MeSH terms

  • Animal Husbandry
  • Animals
  • Biodegradation, Environmental
  • Cattle
  • Microalgae / physiology*
  • Photobioreactors*
  • Waste Disposal, Fluid / methods*
  • Wastewater / chemistry*

Substances

  • Waste Water