This is from "Science for Environment Policy / Issue 176" (service from the European Commission)
New research has developed a system to monitor municipal waste. It uses sensors to calculate the weight, volume and, potentially, type of waste, identify hazardous waste and optimise the routes of waste collection trucks.
The EU's Sixth Environment Action Programme identifies waste prevention and management as one of four top priorities1. In the EU, approximately 3562 million tons of waste are thrown away every day. The research, funded by Italian Ministry for Environment, Land and Sea and partly funded by the EU-China Energy and Environment Programme2, developed an early detection system in Shanghai, China for monitoring the content of waste containers that could help manage the waste situation. The Pudong area in Shanghai generates about 2820 tons a day and this figure is set to increase.
In the past, such systems have only been able to monitor the level of content within the container, but this study investigated other properties. The system consists of a set of sensors and a camera mounted onto the containers to estimate the weight of the waste, its volume and the type. The sensors could also measure the temperature inside the container and liquid levels. Geographic data on the location of the container was also recorded. After significant development in the laboratory, two fully equipped prototypes were tested in the Pudong area in real conditions.
The system successfully measured weight and volume of waste, providing a means to monitor the overall amount of waste. Another goal of the system was to detect materials that could be a potential risk for the incineration plant, such as bricks or concrete. This could be done by calculating the density using weight and volume data. From this, the researchers could calculate a density threshold over which the content might be considered risky. This was estimated at 1kg per litre over more than 1000 trials during field tests.
The second objective of the system was to devise the most efficient route for the waste collection trucks. Again, this used measurements of waste weight and volume. Assuming that a truck can only hold a certain amount of waste and must serve a certain number of waste collection points, routes were identified to make collection as efficient as possible, specifying the location and order of collection points. This led to reduced traffic emissions and costs and helped prevent and manage problems with collecting waste.
The researchers suggest that most issues related to municipal waste (monitoring, sorting, accounting, reduction policies, pollution surveys) could benefit from gathering data at each single production point to be sent wirelessly over the town. As well as developing this data-collecting capacity, the researchers intend to assess the economic impact of fitting the equipment on standard waste containers.
Source: Rovetta, A., Xiumin, F., Vicentini, F. et al. (2009). Early detection and evaluation of waste through sensorized containers for a collection monitoring application. Waste Management. 29:2939-2949