Reverse Household Waste Flow Mapping

Abstract

Our linear way of producing has to come to an end. More and more companies and government institutions see the value of circularity of raw materials. The municipal- ity of Amsterdam published several reports to clarify the directions towards circu- larity. A report on waste-chains highlights the importance of organic residual flows for circular economy transition. This thesis focuses on organic residual streams, the lack of understanding of these streams has been mentioned as an obstacle to plan- ning by many of regional stakeholders. The topic of this thesis is formulated within the context of the REPAiR project by the AMS Institute. The starting point of this thesis is the waste collection location in public space and follows the waste back to the retailers of food. The households are identified, after which the used trashcan and the retailers of food are identified.
To create the geographical connection between the three nodes in this thesis, a related works research is conducted. The main source of food waste is food retail and the main disposal is collection of residual waste. Since the municipality of Amsterdam is not collection organic waste separately, residual waste is considered. Multiple researches added spatial dimensions to their material flows, trying to cre- ate a better insight in sinks and flows of the chains. Household level is not reached. This leads to the research question: How can household waste flows be mapped in reverse based on their environment?
To create the mentioned connections, two main methods are developed. First, the method household-to-trashcan and second, the method household-to-retail. The first method is simulating the pedestrian path from a household towards their used trashcan. A least cost raster is created from the BGT, the direct environment is translated into walkability values representing the willingness to walk on a certain object. By comparing the paths to different trashcans, the trashcan reachable with the smallest least cost value is picked. Another factor is inserted, considering that walking to the trashcan is mandatory trip, executed in as less time as possible, city hotspots are inserted. The hypothesis suggests that people are willing to walk further, if the residents can combine their trip to the trashcan with their trip to, for example, the supermarket. By changing the values in the least cost raster, this direction is made preferable. After the validation of this method is concluded, that a stronger influence of the city hotspot (among the tested values), results in a higher positive correlation of the number of households per trashcan and the mass of waste in the trashcan in kg.
The second method household-to-retail, is a demonstration, due to the uncer- tainly and the many involved personal factors. Food retailers in different isochrone areas are given importance values based on their distance towards the considered household and the floor size of the retailer.
After establishing the connections from trashcan to household and from house- hold to food retail, reverse distribution of the waste measure in the trashcan can be executed. In this way is known which household contributed how many kg per year to the trash composition of the used trashcan. When adding the other step, the contribution by the food retailers can be given.
This thesis generates the first step in mapping residual waste flows touching household level. Promising positive correlations between the number of households using a trashcan and the kg measured inside this trashcan are shown. The method household-to-retail cannot be validated and is therefore only a demonstration. The outcome of this thesis is a step in the right direction to be able to follow waste through the waste chain, by analyzing results in trash composition and knowing which households and retailer contribute to this composition.