Deliverable 4.3 - Relevant contaminants: selected list of relevant contaminants to be monitored in Task 3.1

Abstract:

This Deliverable 4.3 is a part of activities to be performed in the frame of WP4 Regulatory Challenges, Task 4.3 “End-of-Waste” Criteria.

In particular, this Deliverable reports about the recognition made in order to evaluate which contaminants are of possible concern when using urban bio-waste as a renewable resource to be transformed into bio-products and namely into bioplastics.

In fact, the processing of urban bio-waste leading to new bio-based products should be carried out in full agreement with existing and future regulatory framework. The “End of Waste Criteria for Biodegradable Waste Subject to Biological Treatment (Digestate and Compost)” (as defined by the Joint Recent Centre) are the present reference for what can be considered or not a waste when transforming a biodegradable waste to compost or digestate. However, when new materials are recovered or synthesized from biodegradable waste, such as in the case of RES URBIS approach, that criteria are not anymore applicable; it is therefore necessary to define the status of new materials by opening the way for a future adaptation of End of Waste criteria. To a greater reason, this issue holds for the specific case of waste biorefinery because several urban organic waste streams are combined (especially the organic fraction of municipal solid waste and the excess sludge from urban wastewater treatment) and conversion processes are also novel with respect to state of the art (i.e. biological synthesis of PHA from ad hoc derived precursors instead of simply composting. For these reasons, several literature sources were considered for this analysis, as it follows:

a) Analysis of underlying criteria of “End of Waste Criteria for Biodegradable Waste Subject to Biological Treatment (Digestate and Compost)” (as defined by the Joint Recent Centre) which are the present reference of when and how products from organic waste cease to be considered a waste.

b) At the same time, analysis of existing regulatory framework for plastic and bioplastic materials.

c) More general review of the scientific knowledge about the presence of contaminants in different types of organic waste under consideration and of their environmental fate for conventional processes.

Based on such analysis, three categories of contaminants have been selected and are described in this report:

a) heavy metals

b) poly-aromatic hydrocarbons (PAH)

c) polychlorinated biphenyls (PCB)

This selection will give input to the experimental activity which is planned at the Treviso pilot scale platform (see Task 3.1).

Indeed, the selected families of contaminants will be searched for in PHA samples, which are produced in the pilot-scale process starting from true urban bio-waste. Based on results, the need for searching these contaminants backward along the production steps (e.g. in the VFA mixture from the acidogenic fermentation step) or in the feedstock will be also evaluated.