Advances in Recycling & Waste Management

Today’s generation, commercial erythritol is produced through free-cell fermentation with fungi in liquid media containing high concentrations of pure carbon sources. Alternative fermentation techniques, such as cell immobilisation, could result in an economic and energy improvement for erythritol-producing factories. The current study describes for the first time the feasibility of achieving cell immobilisation during erythritol production. Moniliella pollinis cells were successfully immobilised on a cotton cloth and placed inside a 2-L bioreactor, where they were fed red grape must supplemented with yeast extract. The similar results obtained for free and immobilised cells demonstrate the effectiveness of the immobilisation system. As a result, the proposed method for erythritol bioproduction eliminates the need for continuous preparation of fungal inocula before each fermentation batch,lowering reagent and energy costs.

Wood biomass is widely used as a fuel in the European Union to generate heat and electricity, resulting in a significant amount of ash. Because ash particles contain heavy metals and can easily pollute soil, groundwater, or air, proper engineering solutions are required for ash disposal, particularly in its finest fraction. In this study, wood fly ash with a high pozzolanic oxide content and one with a high CaO content were used in concrete as a 15% and 30% cement replacement, respectively. Wood ash incorporation in concrete reduced the 28-day compressive strength by up to 37%, which was attributed to the low stiffness of the wood ash particles, whereas the 2-year compressive strength indicated very low pozzolanic reactivity.