Search results for "Waste collection"
showing 10 items of 12 documents
Iterated greedy with variable neighborhood search for a multiobjective waste collection problem
2020
Abstract In the last few years, the application of decision making to logistic problems has become crucial for public and private organizations. Efficient decisions clearly contribute to improve operational aspects such as cost reduction or service improvement. The particular case of waste collection service considered in this paper involves a set of economic, labor and environmental issues that translate into difficult operational problems. They pose a challenge to nowadays optimization technologies since they have multiple constraints and multiple objectives that may be in conflict. We therefore need to resort to multiobjective approaches to model and solve this problem, providing efficie…
The mixed capacitated general routing problem with turn penalties
2011
In this paper we deal with the mixed capacitated general routing problem with turn penalties. This problem generalizes many important arc and node routing problems, and it takes into account turn penalties and forbidden turns, which are crucial in many real-life applications, such as mail delivery, waste collection and street maintenance operations. Through a polynomial transformation of the considered problem into a Generalized Vehicle routing problem, we suggest a new approach for solving this new problem by transforming it into an Asymmetric Capacitated Vehicle routing problem. In this way, we can solve the new problem both optimally and heuristically using existing algorithms. A powerfu…
Municipal waste management in Sicily: practices and challenges.
2006
There are numerous problems yet to be solved in waste management and although efforts towards waste recovery and recycling have been made, landfills are still the most common method used in the EU and many other industrialised countries. Thermal disposal, particularly incineration, is a tested and viable alternative. In 2004, only 11% of the annual waste production of Italy was incinerated. Sicily, with over five million inhabitants, is the second largest region in Italy where waste management is now a critical problem. The use of landfills can no longer be considered a satisfactory environmental solution; therefore, new methods have to be chosen and waste-toenergy plants could provide an a…
Experiencing Urban Mining in an Italian Municipality towards a Circular Economy vision
2017
Abstract Selective waste collection in Italy has undergone significant changes over the last decade, highlighting very different approaches from one region to another. Research results presented in this paper are underlying differences between geographical regions and use them as a model of good practices to improve the less optimized systems. In the last decade, the Trento City Council has established a goal – the optimization of selective municipal solid waste collection – that led to a very low amount of recyclable materials in the residual fraction. More than that, for the first time sanitary textiles have been considered as a separable fraction at the source; for a long time this type …
Lower and upper bounds for the mixed capacitated arc routing problem
2006
This paper presents a linear formulation, valid inequalities, and a lower bounding procedure for the mixed capacitated arc routing problem (MCARP). Moreover, three constructive heuristics and a memetic algorithm are described. Lower and upper bounds have been compared on two sets of randomly generated instances. Computational results show that the average gaps between lower and upper bounds are 0.51% and 0.33%, respectively.
Biogas yield from Sicilian kitchen waste and cheese whey
2013
The aim of this study is to determine the chemical composition of kitchen waste and cheese whey, as well as the biogas yield obtained from the Anaerobic Digestion (AD) tests of these two raw materials. Since the separated waste collection is performed in the town of Marineo (Palermo), a sample of kitchen waste, different from food industry one and included in the Organic Fraction of Municipal Solid Waste (OFMSW), was collected from the mass stored at the households of this town. Moreover, a sample of cheese whey was collected in a Sicilian mini dairy plant, where sheep milk is processed. This investigation was carried out inside laboratory digesters of Aleksandras Stulginskis University (Li…
Overcoming managers’ myopic decisions in a waste collection company
2019
Purpose The purpose of this paper is to show how the changing interrelationships between fleet management, human resources and outsourcer capacity areas are likely to counterbalance managerial policies, thereby generating a performance decay. The use of system dynamics modelling in a waste collection company offered an effective contribution to support decision makers to overcoming myopic decisions. Design/methodology/approach Literature review and a case study analysis (including interviews with company actors and data gathering) offered the basis to build a system dynamics model. The model built was then used to run simulations sessions to assess alternative investments decisions. Findin…
Experimental Sorting of Municipal-Like Waste in the Hospital “Civico”, Palermo (IT)
2013
An experiment of source sorting - based management of Health Care Waste (HCW) was carried out in 2011 in 4 Departments of the Public Hospital “Civico” (Palermo, IT), where the basic mandatory separation between hazardous and non-hazardous waste was already going on since year 2000.The experiment consisted in weighing every day for 15 days 4 predefined fractions collected in the Infirmaries (namely paper, plastics, glass and unsorted fraction), and the bags with unsorted waste from the patient’s stay room. Furthermore, in 1 of the 4 Departments also the boxes of Infectious Waste (IW) were weighed for a week.As a result a weighted average value of 0.56 kg of Municipal-like Waste (MLW) per bed…
Improved route planning and scheduling of waste collection and transport
2006
The collection of waste is a highly visible and important municipal service that involves large expenditures. Waste collection problems are, however, one of the most difficult operational problems to solve. This paper describes the optimization of vehicle routes and schedules for collecting municipal solid waste in Eastern Finland. The solutions are generated by a recently developed guided variable neighborhood thresholding metaheuristic that is adapted to solve real-life waste collection problems. Several implementation approaches to speed up the method and cut down the memory usage are discussed. A case study on the waste collection in two regions of Eastern Finland demonstrates that sign…
Municipal Solid Waste Management in the Accra Metropolitan Area, Ghana
2003
Municipal solid waste management in Accra, Ghana, is at present delivered in an unsustainable manner. Due to uncontrolled urbanisation, large quantities of waste are generated daily in Accra, and this exerts much pressure on an over strained solid waste management system. Coupled with weak institutional capacity, and lack of resources, both human and capital, the city authorities face difficulties in ensuring that all the waste generated in the city is collected for disposal. Home collection of waste is limited to high and, some middle income areas while the poor are left to contend with the problem on their own. This leads to indiscriminate disposal of waste in surface drains, canals and s…