Hondakin-uren Araztegietan Sortutako Lokatzei Balioa Emateko Estrategia Berriak

Abstract

The amount of sludge produced in wastewater treatment has increased significantly over the last decades, due to industrialization and urbanization. Sewage sludge is composed of toxic and pathogenic substances, and consequently, the improvement of its management and the search of new strategies is an issue of particular concern. Among the traditional options to manage sewage sludge, incineration and composting have been widely used. Nevertheless, nowadays the valorization of sludge by means of a thermochemical procedure is proposed as an economical and sustainable strategy. The solid material obtained (biochar or sludge carbon) is a material with a wide range of applications. This work addresses the production of sludge during wastewater treatment, along with its characteristics and composition. Moreover, the preparation methods of biochar are discussed (physical activation, chemical activation and hydrothermal carbonization, among others). The characterization of biochar (mainly composition and morphology) is also explained. Finally, the potential applications of biochar are discussed: as an adsorbent, in catalysis, in gas storage (for example, H₂, O₂ and CH₄), as a soil amendment and as a biofuel. The optimal physicochemical properties of biochar depend on the desired application, and they can be adjusted by means of the preparation procedure.