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Anaerobic DigestionBiological processesBioplasticCircular economyESTECHESTECHFORSUOFMSWPHAsProcessi biologiciZero Waste


The proposed invention describes a process for biosynthesis of Polyhydroxyalkanoates (PHAs) from the organic fraction of domestic solid waste. The method uses mixed microbial cultures (MMCs) and is based on the combination of a three-stage biological process in sequence with a two-step fermented flow filtering system to reduce the concentration of suspended solid particles and nutrients.

Technical features

The method is adapted to reuse domestic or other organic waste, with a residual solids content greater  than 10.0 g/L, as raw material in the production of bioplastics and biogas. The method is based on the combination of a biological process in three sequential phases (Phase I: anaerobic fermentation, Phase II: sequential aerobic fermentation, Phase III: batch aerobic fermentation), with a flow filtering system. After a first filtration of the discharge from Phase I, the flow is divided between the reactor for Phase II, where the biomass is produced and a membrane filter before entering Phase III, where the PHAs is accumulated. This second filtration step reduces the concentrations of particulate matter and nutrients, favoring the synthesis of PHAs.

Possible Applications

  • Treatment of Organic Fraction of Municipal Solid Waste (OFMSW) or other fermentable organic waste;
  • Production of biogas.


  • Reuse of organic waste with TSS > 10.0g/L;
  • Two different solids removal steps;
  • First filtration favors specialized biomass production;
  • Second filtration favors maximization of PHAs production.