A research study submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1986

A study is carried out to design a collection and transportation system of solid wastes for the city of Kathmandu. Generation rate of solid wastes is the basic data requirement for the solid wastes management programme. The trend of solid wastes generation in Kathmandu shows that the generation rate depends not only on the income level of the people, but also depends on the size of the household. An optimum "Postman Tour" was determined in the road network of Kathmandu city with 54 nodes and 106 links. The shortest distance from depot to each of the nodes was also determined. Simulation was carried out to determine the number of trips and minimum cost of collection and transportation of solid wastes, by forcing the collection vehicles through the "Postman Tour", while considering vehicle capacity and working hour as constraints. Various criteria and alternative combinations were used to determine the least cost alternative. Smaller waste bins which can be easily handled by a crew is the least cost solution for the selection of waste bin, but they have other practical difficulties. It is cheaper to allow overtime for the collection Vehicles which to restrict their running within the working hour, which increases the number of trips. of the various returning trip criteria tested, the one which allows the vehicle to start a new trip if the total remaining time is greater than or equal to the rest time plus 20% of the total time consumed in the previous trip yields the least cost. Height of collection vehicle has significant effect in the loading rate of the waste bins if loading operation is to be carried out from the side of the vehicle.