NOVELTY - The bioprocess engineering method comprises supplying an aqueous phase of an anaerobic biologically treated organic suspension as a media component in an algae culture. The aqueous phase is separated from the anaerobic biologically treated organic suspension before feeding into the algae culture. The aqueous phase is a filtrate and collects from a methane fermentation process. The anaerobic biologically treated organic suspension and/or the aqueous phase is microfiltrated or ultrafiltered once before feeding into the algae culture with a dynamic rotating disk filter.    USE - Bioprocess engineering method useful for producing biomass from an algae culture and/or reusable materials, and purification of aqueous-phase of anaerobic biologically treated organic suspension such as wastewater effluent as a media component in the algae culture for improving the conditions of growth of algae in photobioreactors (all claimed).    ADVANTAGE - The bioprocess engineering method ensures production of biomass and purification of aqueous-phase without harmful to the environment and the population.    DETAILED DESCRIPTION - The bioprocess engineering method comprises supplying an aqueous phase of an anaerobic biologically treated organic suspension as a media component in an algae culture. The aqueous phase is separated from the anaerobic biologically treated organic suspension before feeding into the algae culture. The aqueous phase is a filtrate and collects from a methane fermentation process. The anaerobic biologically treated organic suspension and/or the aqueous phase is microfiltrated or ultrafiltered once before feeding into the algae culture with a dynamic rotating disk filter, a dynamic polymer filter or a ceramic depth filter. The anaerobic biological cleaning is carried out before feeding the aqueous phase into the algae culture as a single stage or two stage methanation or methanation in cascade manner. The unpurified organic suspension is sewage sludge, organic waste, wastewater from food industry, effluent from municipal wastewater and/or wastewater from fermentation of renewable raw materials. The aqueous phase contains 50 wt.% of a media component for the algae culture medium. Trace elements are added to the aqueous phase. The algae culture is a microalgae culture such as Phaeodactylum tricornutum culture or Haematococcus pluvialis culture or Chlorella sorokiniana culture or Chlorella vulgaris culture or Platymonas subcordiformis culture or Tetraselmis suecica culture or Nannochloropsis oculata culture, Nannochloropsis limnetica culture or Phormidium species culture or Pseudoanabaena species culture or Dunaliella species culture or Monodus subterraneus isochrysis species culture. The algae culture is cultivated in a photo bioreactor (3). An INDEPENDENT CLAIM is included for a bioprocess engineering device.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of a bioprocess engineering device.    Bioreactor (1)    Filtration device (2)    Photobioreactor (3)    Mixing device (11)    Drainage. (25)