Chemical Process Engineering and Forest Products Research Centre

Waste and Soil Engineering

Recycling/Valorization and Waste Management. With respect to the broad area of waste management, recycling and valorization of solid waste has been considered as priority routes. Aiming to recycle/valorize inorganic wastes (e.g. fly ashes) ceramic material has been addressed. In the case of organic biowastes, composting processes for producing soil conditioning materials has been studied. In specific situations, the treatment of solidification/stabilization is also considered in order to improve disposal in landfills. All these studies are based on deep characterization analysis, involving physical and chemical properties, leaching behavior and speciation modeling.

Composting. Composting studies have been performed into a pilot plant located in our laboratory, where compositions involving diverse materials have been tested. The mixture design approach has been used to establish the right formulations. The characterization analysis comprises raw material, along the process (monitoring) and also the finished composts. At the end, it is always demonstrated the stability and maturity of the composts. The kinetic studies have been conducted in collaboration with Aveiro University. The mathematical modeling of the process has also been considered in order to simulate the process and optimize its operating conditions.

Life Cycle Assessment (LCA). LCA methodology is used to identify and qualify the environmental performance of a process or a product from “cradle to grave, in four steps: goal and scope definition, life cycle inventory analysis, life cycle impact assessment and life cycle interpretation. This analysis has been performed through Simapro7.0 code and CML 2000 method responsible for the transformation of the characterization factors on quantified effect on environment. The case study under analysis is the recycling of fly ashes into lightweight aggregates.

Soil remediation. Soil remediation has been addressed in cooperation with Escola Superior Agrária de Coimbra, and involves the analysis of soil contaminated with PCB or heavy metals. In the case of PCB, the studies are based on coupling electrokinetic techniques and nanoparticles remediation for in-situ applications. For heavy metals the remediation entails mainly their stabilization with calcium-rich composts (obtained by composting processes).