Iranian Journal of Environmental Health Science & Engineering, Vol. 2, No. 4, 2005, pp. 267-272
EVALUATION OF CHRONOLOGICAL ASPECTS OF COLLECTION AND TRANSPORTATION OF MUNICIPAL SOLID WASTE SYSTEM IN URMIA
*1A. Jalilzadeh and 2A. Parvaresh
1Environmental Engineering Department, Urmia University of Medical Sciences, Urmia, Iran
*Corresponding author: Tel: +98 461 2232169, Email: firstname.lastname@example.org
Received 16 October 2004;
Code Number: se05039
Municipal solid waste (MSW) is a serious environmental hazard and social problem in Iran. Currently a high volume of solid waste is generated every day in the district towns of Iran and unfortunately solid waste management is being deteriorated due to the limited resources to handle the increasing rate of generated waste. Due to this fact that more than 60% of solid waste management cost is usually alocated for purpose collection and transportation of generated solid waste in the city. Analysis of this section and understanding of its effect on the management system could have a great role in reduction the costs and solving many of exist problems. This study illustrate the effectiveness of timing managing an MSW economy and that has been carried out as a case study in Urmia. Results of this research illustrsate that 58.3% in Neisan, 68.7% in Khavar, 61.5% in Benz, 81.3% in Compactor and 59.3% in FAUN 0f each cycle time is pickup time. Mean of traveling speed for Van, Mini-truck, Truck, FAUN and Compactor was 35,46,41,38 and 42 kilometer per hour respectively. Total spent time for collection and transportation of solid waste were 1:21 hour with Van, 1:23 hour with Mini-truck, 1:29 hour with Truck, 17 minutes with FAUN and 57 minutes with Compactor. Result of this study illustrated Van is the most economic vehicle for solid waste collection system in Urmia city. Generally, priority to usage of solid waste collection vehicles illustrate in below: Truck < Mini-truck < Compactor < Van < FAUN
Key words: Municipal, solid waste, transportation, collection, timing components
Urmia City "west Azarbayjan province" is located in the west north of Iran and its area is 74 km2 (Arseh Co., 2001 and Moshrefi, 1993). Its latitude is 37º 32´ and 45º 5´ E and its altitude is about 1330 meters above free seas level (Arseh Co., 2001 and Moshrefi, 1993). Urmia population is equal to 550,000 capita. This city is divided to 4 districts and 6 sub districts (Fasih, 1998 and Ghanbari, 2003). Solid waste collection costs depend on various parameters such as: recycling rate, collection scheme, time consumed for collection and transportation to landfill site. It is determined that the average collection cost per ton of collection waste equal to 114-120 $. (Miller,1993). Identifying efficient collection time will help engineers minimize program costs and introduce the best collection method.
Everett W. and Maratha S. were investigated about pickup time in Village city in U.S.A on 1998 (Everett et.al., 1998).
Five types of vehicles include Vans, Trucks, Mini trucks ,compactors and FAUN is used in solid waste collection system of Urmia. All vehicles except Van haule collected solid waste to landfill that is place in 17 km north of city. Vans haule collected solid waste to transfer staion that is place approximately in 8 km south of city; Urmia has just one lanfill and one transfer station. Unfortunately some of them are not suitable for solid waste collection and based on economic and health reasons its application isn't acceptable.
The objectives of this research are to:
MATERIALS AND METHODS
Data were collected by observing and calculation the collection of solid waste in Urmia during 3 months in May to July 2005. These months approximately have a equal solid waste generation coafficient with annual average in Urmia (Table 1), therefore they select for this research.
The spent time per component of collection operation measured by two chronometer. Number of repetitions determined according to Fig.1.
Minimum time to pickup and discharge a waste package into Truck is 0.5 minutes. According to Fig.1 minimum number of repetition for this component is equal to 60. Also, average transportation time by trucks is equal to 30 minutes (EPA, 1995). Therefore minimum number of repetition for determination the transportation time by each vehicle is equal to 10. To create a logical relation between the traveling time per each collection service and distance between collection zone and landfill site, a mathematical model was used. According to this model the duration of each traveling can be estimated as: (Abdoli, 1992 and Tchobanoglous, 1993). Y= A+BX Where: y = duration time of each traveling for service, x = distance between landfill site and collection zone (for all vehicles except Vans), for Vans x= distance between transfer station and collection zone, A, B = empirical coefficients.
These relations correlated by using excel software for various collection vehicles in Urmia.
Table 2 illustrates the results of total collection time for each vehicles to studied regions in Urmia. These results indicate that pickup time per each ton solid waste with FAUN is maximum and equal to 11 minutes. The ratio of pick-up time to total time of collection for Van, Mini truck, Truck, compactor and FAUN is respectively 3.58%, 7.68%, 5.61%, 3.81% and 3.59%. It is observed that the Van has the least ratio and the compactor has the highest ratio. Theorically, its efficiency must be higher than other vehicles, but the total time of collection per each ton of solid wastes for this type of vehicles is more than other, and equal to 57 minutes.
The mean total hauled time per each ton for hauled wastes per trip for Van, Mini truck, Truck, compactor and FAUN is respectively 27, 22, 9 and 6 minutes. Therefore the total hauled time of Truck and Van is more than others. This parameter for compactor is the least. The main reason of this high time for Truck is its incompatibility for solid waste collection and doesn't use the total vehicle capacity.
Based on measurements during this research, only 50% of Truck nominal capacity (approximately 2.5-3 tons) has been used for solid waste collection. This reason for Van comes back its small container with low volume and long distance between collection region and transfer station (approximately 8 km.).
The most time required for discharging each tons of solid waste by Van is equal to 4 minutes and the least of them is related to compactor that equal to 49 seconds per tons hauled solid wastes. The effective reasons of being high of discharging time for Van can be interpreted as follow:
The timing comparison of Solid waste collection in Urmia per each ton of Solid wastes and total time of each collection cycle for various vehicles demonstrate in Fig. 2 and Fig. 3. This is resulted that the FAUN has the least time in collection and transportation solid wastes. Therefore this vehicle is the most economic vehicle in Solid waste management. Also the Truck need the most time for collection and transportation of Solid wastes per each ton and it is a non-economic vehicle. The reasons of this trend can be interpreted as follow:
Reasons of increasing pickup time per each ton of Solid waste for Truck in comparison with other vehicles can be interpreted as follow:
The hauled time for various vehicles in Urmia collection system is illustrated in table 3. The Mini truck has the most speed and Van is slowest vehicle. The main reason is that the Van most passes though crowded streets and faces with traffic.
Solid waste collection operation starts at morning therefore the Vans must pass through crowded streets for hauling the waste to transfer station and face with the morning traffic. Therefore the Vans speed become slow. However, for following reasons, transfer station don't need for this system:
The results of mathematical correlation of vehicles hauling speed between landfill site and transfer station demonstarted in Fig. 4 and Table 4. There is observed a logical relation between the hauling time per each tripe and crossed distance from collection zone to landfill site. The slope of all curve's for vehicles except Truck and Mini-truck is positive that this factor affect directly on this vehicles amortization.
The results of this research can be summarized as follows:
The authors are greatly indebted to recycle and recovery organization of Urmia especially Eng. Mortaz, for their honestly corporation during this research.
© 2005 Tehran University of Medical Sciences Publications
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