The European Union (EU) area has the second largest world sheep population, numbered to about 87 millions, the majority of them being located in the United Kingdom (26.37 %), Spain (17.67 %), Romania (10.90 %), Greece (11.11%), Italy (8.20 %), France (8.20 %) and Ireland (3.80 %) (Source EU-Eurostat 2014). The EU flock is made of crossbred sheep not graded for fine wool production; the primary role is meat, whilst the milk market is relatively small, being confined to Mediterranean regions. The annual wool clip amounts to about 200 000 t and its management is a specific problem for the EU livestock sector. Indeed, wool from sheep farming and butchery industry is very coarse and contains a lot of kemps (dead fibres), making it practically unserviceable for the textile industry. The use for filling mattresses has been outclassed by synthetic materials, so that there is no market for crossbred wool, excluding handicraft niches. Unserviceable wool is mostly disposed in landfills or illegally thrown over, with serious ambient threats since it can affect the pastures and bring illness if leave out on soil, where it does not readily degrade. Thus, shearing, storage, transportation and disposal of waste wool in accordance with current EU Regulation, heavily weigh on the profit of sheep farming. The Life+ 12 ENV/IT000439 GreenWoolf, supported by the LIFE 2012 EU financial instrument, aims at converting waste wool into nitrogen fertilizers at a commercial scale for grassland management and cultivation purposes. The chemical transformation is based on a green economically sustainable hydrolysis treatment using superheated water. The experiments were carried out in a semi-industrial reactor feeding superheated water and, due to condensation, the wool/superheated water system was maintained for different reaction times. The optimal conditions for this treatment were: 170 oC for 60 min with a solid to liquor ratio (MLR) close to 1. Chemical analyses such as amino acid analysis and molecular weight distribution performed on the hydrolysis products obtained revealed that the wool was completely degraded, the reaction product containing low molecular weight proteins and amino acids. Several product batches tested for germination showed an index higher than 100% without collateral phytotoxicity. The presence of amino acids, primary nutrients and micronutrients in wool hydrolyzates, along with a concentration of heavy metals below the standard limit, confirms the possibility of using wool hydrolyzates as nitrogen based ecologically sound fertilizer.
Life 12 ENV/IT000439 Greenwoolf: Green Hydrolysis Conversion of Wool Wastes into Organic Nitrogen Fertilisers
M Zoccola;M Simionati;R Mossotti;A Montarsolo;A Patrucco;C Tonin
2016
Abstract
The European Union (EU) area has the second largest world sheep population, numbered to about 87 millions, the majority of them being located in the United Kingdom (26.37 %), Spain (17.67 %), Romania (10.90 %), Greece (11.11%), Italy (8.20 %), France (8.20 %) and Ireland (3.80 %) (Source EU-Eurostat 2014). The EU flock is made of crossbred sheep not graded for fine wool production; the primary role is meat, whilst the milk market is relatively small, being confined to Mediterranean regions. The annual wool clip amounts to about 200 000 t and its management is a specific problem for the EU livestock sector. Indeed, wool from sheep farming and butchery industry is very coarse and contains a lot of kemps (dead fibres), making it practically unserviceable for the textile industry. The use for filling mattresses has been outclassed by synthetic materials, so that there is no market for crossbred wool, excluding handicraft niches. Unserviceable wool is mostly disposed in landfills or illegally thrown over, with serious ambient threats since it can affect the pastures and bring illness if leave out on soil, where it does not readily degrade. Thus, shearing, storage, transportation and disposal of waste wool in accordance with current EU Regulation, heavily weigh on the profit of sheep farming. The Life+ 12 ENV/IT000439 GreenWoolf, supported by the LIFE 2012 EU financial instrument, aims at converting waste wool into nitrogen fertilizers at a commercial scale for grassland management and cultivation purposes. The chemical transformation is based on a green economically sustainable hydrolysis treatment using superheated water. The experiments were carried out in a semi-industrial reactor feeding superheated water and, due to condensation, the wool/superheated water system was maintained for different reaction times. The optimal conditions for this treatment were: 170 oC for 60 min with a solid to liquor ratio (MLR) close to 1. Chemical analyses such as amino acid analysis and molecular weight distribution performed on the hydrolysis products obtained revealed that the wool was completely degraded, the reaction product containing low molecular weight proteins and amino acids. Several product batches tested for germination showed an index higher than 100% without collateral phytotoxicity. The presence of amino acids, primary nutrients and micronutrients in wool hydrolyzates, along with a concentration of heavy metals below the standard limit, confirms the possibility of using wool hydrolyzates as nitrogen based ecologically sound fertilizer.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
