Environment-Friendly Wool-Geopolymer Pots For Plant Growing

Disposal of wool waste still encounters significant problems due to the need to satisfy environmental legislation and to the increasing cost of landfilling. Conversely, sheep wool waste could still have a great potential for many applications. In this work, the possibility of reusing wool scraps as a constituent material for plant pots, producing innovative wool-geopolymer composite artifacts, is highlighted. Beside the valorization of the wool waste, these pots could contribute to limit the use of peat or plastic pots, thus protecting peatlands and reducing plastic wastes. Environmental-friendly pots for plant growing have been designed and realized by impregnating wool scraps with a geopolymer matrix. The formulation of the inorganic matrix was designed to accomplish workability of the composite mixture, good alkaline driven matrix-wool interaction together with good geo-polymerization degree. The germination of seeds and the plant growth were stimulated in the wool-geopolymer pots compared to peat ones. Composite characterizations and comparative evaluations of pH and moisture in the soil were performed during the experiment. Wool fibers' hygroscopicity ensured an excellent humidity control: the moisture was entrapped and slowly released in the soil, thus lowering the watering time and amounts and fastening the early germination of seeds. The geopolymer chemical inertness prevented an excessive leaching in the soil and did not generate any evident pH alteration.