Municipal Solid Waste Transfer Research Articles

Conceptual modeling to optimize the haul and transfer of municipal solid waste

Two conceptual mixed integer linear optimization models were developed to optimize the haul and transfer of municipal solid waste (MSW) prior to landfilling. One model is based on minimizing time (h/d), whilst the second model is based on minimizing total cost (euro/d). Both models aim to calculate the optimum pathway to haul MSW from source nodes (waste production nodes, such as urban centers or municipalities) to sink nodes (landfills) via intermediate nodes (waste transfer stations). The models are applicable provided that the locations of the source, intermediate and sink nodes are fixed. The basic input data are distances among nodes, average vehicle speeds, haul cost coefficients (in euro/ton km), equipment and facilities' operating and investment cost, labor cost and tipping fees. The time based optimization model is easier to develop, since it is based on readily available data (distances among nodes). It can be used in cases in which no transfer stations are included in the system. The cost optimization model is more reliable compared to the time model provided that accurate cost data are available. The cost optimization model can be a useful tool to optimally allocate waste transfer stations in a region and can aid a community to investigate the threshold distance to a landfill above which the construction of a transfer station becomes financially beneficial. A sensitivity analysis reveals that queue times at the landfill or at the waste transfer station are key input variables. In addition, the waste transfer station ownership and the initial cost data affect the optimum path. A case study at the Municipality of Athens is used to illustrate the presented models.

Environmental monitoring and fuzzy synthetic evaluation of municipal solid waste transfer stations in Beijing in 2001–2006

Transfer station (TS) is an integral part of present-day municipal solid waste (MSW) management systems. To provide information for the incorporation of waste facilities within the current integrated waste management system, the authors measured the existing environmental quality at five MSW TSs. Discharged wastewater, air, and noise were monitored and assayed at the five TSs in Beijing in 2001-2006 during rainy seasons (RSs) and dry seasons (DSs). Except Ammonia (NH3) and hydrogen sulfide (H2S), the analytical results of total suspended particles (TSPs), odor, noise, ammonium nitrogen (NH4(+)-N), chemical oxygen demand (COD(Cr)), biochemical oxygen demand (BOD5), suspended solid (SS), and fecal coliform concentrations were all degree-varied higher than the criteria limit in China. Using fuzzy mathematics, the environmental quality of MSW TSs in Beijing was classified into five categories, with levels of certainty of belonging to different categories and evaluations. The result indicated that the whole environmental quality of Datun TS, Majialou TS, and Xiaowuji TS, in Beijing, were bad during 2001-2006 in RSs and DSs. Except in 2002, the entire environmental quality of the Wuluju TS during 2001-2006 in RSs was poor. Only in the DSs of 2002 and 2003 was the whole environmental quality of the Wuluju TS good. The whole environmental quality of the Yamenkou TS during 2001-2006 in DSs was bad, which was lower than that of 2001-2006 DSs.

Institutional and management approaches to solid waste disposal in large metropolitan areas

There are significant advantages to a consolidated institutional approach to the management of municipal solid waste transfer and disposal in large metropolitan areas. Both operational and environmental benefits can be achieved. On the other hand, it is argued that collection services do not necessarily benefit from centralization, since there are only limited economies of scale. Furthermore, there is abundant evidence that the private sector can provide conventional collection services more efficiently than the public sector. This paper examines a model of decentralized collection and centralized transfer and disposal that is in place at Norfolk, Virginia, U.S.A. and which is being applied in Monterrey, Mexico. The partial application of this model in the Federal District of Mexico City is also examined. Lessons are drawn for the application of such a model to metropolitan areas in other developing countries.

Institutional and Management Approaches To Solid Waste Disposal in Large Metropolitan Areas

There are significant advantages to a consolidated institutional approach to the management of municipal solid waste transfer and disposal in large metropolitan areas. Both operational and environmental benefits can be achieved. On the other hand, it is argued that collection services do not necessarily benefit from centralization, since there are only limited economies of scale. Furthermore, there is abundant evidence that the private sector can provide conventional collection services more efficiently than the public sector. This paper examines a model of decentralized collection and centralized transfer and disposal that is in place at Norfolk, Virginia, U.S.A. and which is being applied in Monterrey, Mexico. The partial application of this model in the Federal District of Mexico City is also examined. Lessons are drawn for the application of such a model to metropolitan areas in other developing countries.