Recycling : Reduce, Reuse and Recycle

The MICROALBAC project aims to integrate the cultivation of microalgae in conventional wastewater treatment plants to reduce the energy costs of the systems of oxygenation and agitation of the aerobic reactors as well as the revaluation of the "algal biomass" micro-algae/bacteria through its use as a fertilizer and production of biogas as co-substrate. The effect of the "algal biomass" on plant yield (ryegrass and barley) and soil properties has been evaluated at microcosmos level in comparison with conventional sewage sludge. Five different doses of each organic material have been assayed in quadruplicate. Plants have been grown for two months in a growth chamber and then the aerial part of the plant has been cut and fresh and dry weight as well as nutrients and heavy metal plant content have been determined. Different physical (water holding capacity) chemical (pH, EC, nutrients, heavy metals...) and microbiological parameters (basal respiration dehydrogenase and hydrolase activities) were determined in soils. The effect of this "algal biomass" on lettuce growth has also been evaluated in greenhouse conditions in comparison with the addition of anaerobic sludge and conventional inorganic fertilization