Page 203 - Materials Chemistry, Second Edition

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174 Waste Management Practices: Municipal, Hazardous, and Industrial

FIGURE 7.3 Tipping floor of an MRF.

Common units for storage of processed wastes include:

• Enclosed warehouse space
• Open-sided, roofed structures (i.e., pole barns)
• Roll-off containers
• Shipping containers

Shipping containers tend to serve as an economical storage system. The materials buyer may
provide these containers. This method is popular for the shipping of various grades of paper and
cardboard to overseas markets on container ships (Tchobanoglous et al., 1993).

EXAMPLE 7.1

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Consider a 400 MT/day resource recovery facility. Assume all MSW is received in 15 m (20 yd )
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compactor trucks, providing an average density of 900 kg/m . During a routine work day and
assuming normal equipment operation, how many trucks can be accommodated per hour?
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Truck capacity (15 m 900 kg/m )/1000 kg/MT 13.5 MT/truck
The facility processes MSW 12 h/day, 5 days/week.
MSW processing rate (400 MT/day)/12 h/day 16.7 MT/h 16.7/5 3.3 truckloads/h
Waste collection takes place 5 days/week, 1 shift/day, and only about 7 h/shift are actually used for
on-the-tipping floor processing. Therefore, actual receiving rate (400 5 days)/(5 days 7 h/day)
57 MT/h

(57 MT/h)/13.5 MT/truck 4.2 truckloads/h

In addition to the above, it would be useful to consider hourly peaking factors and seasonal peak-
ing factors in calculations. (Adapted from Schwarz and Brunner, 1983.)