Scenarios for decentralised bio-waste collection chains with a waste collection database for representative situations : DECISIVE Deliverable D3.7 : a decentralised management scheme for innovative valorisation of urban biowaste
This study continues on the topic of bio-waste collection introduced in DECISIVE deliverable 3.5 and aims to add information on how to develop a decentralised collection system by presenting stakeholder opinions, a bio-waste collection database, and bio-waste collection chain scenarios. The study contributes to the development of the DECISIVE decision support tool (DST), which generally aims to assess decentralised bio-waste valorisation schemes and compare them to the common centralised waste management options. In the first part, stakeholder interviews with key players of local areas from the six DECISIVE countries (Belgium, Denmark, France, Germany, Italy, Spain) are described. The results from the interviews provide a good insight into the specifics of local waste management systems. Insider information is received on specific local problems, and on thoughts about solutions. Statements are given considering technical, social, economic and legal information regarding the current waste collection systems. Furthermore opinions of stakeholders on decentralised waste collection systems are documented. Important conclusions were the following: (i) the public waste management sector has to be involved, (ii) initiation projects should consider generators with sufficient food waste amounts (e.g. large food services), and (iii) a new system should have advantages for the generators (citizens, food services), who are also the key for a high bio-waste quality. In the second part, the DECISIVE bio-waste collection database is introduced. The database structure considers the three phases of the collection chain: generation, source-separation, and collection. Each phase includes specific parameters for which data are required. Summaries from the currently available data into the database are provided. Data related to waste focus on food waste from households and from food services and include ranges for each DECISIVE country. Data related to storage and transport is introduced with examples. The issue of data acquisition and data uncertainties is addressed with the example of the EUROSTAT waste database by showing its limitations. To receive data of satisfactory quality, a combination of data collection methods should be applied, combining and comparing different sources for data like statistical surveys, scientific reports and analyses done in municipalities. For a more precise data gathering procedures and information sources are suggested. Since data from common sources are not representative for a specific location, practical investigation within the district where the decentralized system is to be established is suggested. Generally, it can be stated that the risk of failure of a newly implemented process decreases with increasing quality of data used in the conception phase. Finally, eight decentralised bio-waste collection chain scenarios are presented. The core substrate for the scenarios is food waste from households and food services. The scenarios were developed by combining a number of selected parameters. The parameters considered were: the catchment area, the population density, the quantity of source-separated and collected food waste, the quality of source-separated and collected food waste, the collection frequency, the collection system, the transport system, the co-substrate. For each parameter two or four options were provided based on the information previously gathered. In this way the waste collection from the site of the generator to the site of valorisation is described as storyline with illustrative flow sheet extended with mass and energy flow diagrams. The scenarios show the diversity of options. They are compared and each may be useful for a different local situation. In future works, these scenarios will be used to develop precise waste collection processes for specific sites to be included in the DECISIVE DST.
