Question: Book: Solid Waste Engineering 3rd edition William A. Worrell, P. Aarne Vesilind, Christian Ludwig
Worrell, W. A., Vesilind, P. A., & Ludwig, C. (2017). Solid waste engineering: A global perspective (3rd ed.). Boston, MA: Cengage Learning
1) Consider the residential waste components (1st column in Table 2-6 on page p. 53 in the textbook) and answer the following questions:
a. What components of mixed municipal solid waste (MSW) are rejected in storage and sent via truck to the landfill?
b. What components pass through the trommel screen? What components are screened out through the trommel screen?
c. What components that passed through the trommel screen are captured in the magnetic separator? What components are sent to the flattener?
d. What components are removed in the sorting step? See Figure 5-38 (on p.age 225) for additional details.
e. What materials pass through the sorting step and go into the Hammermill shredding operation?
f. What materials are separated in the air classifier operation?
g. How do these processes demonstrate best practices of solid waste management?
2) A local municipality has plans to annex a suburb community of 80,000 people. Neither the municipality nor the community has a curbside recyclinge program as they both put all of their refuse into the trash bin for collection. The municipality hand sorts the refuse and recognizes that they it will need to hire new employees and establish a budget to hand sort a larger amount of waste. Assume the following: (1) hand sorting is done 8 eight hours per day; 5 five days per week and (2) employees are paid $21/hr, and that includes allotted benefits. (For Parts A and B of this question, show all of your work.)
a. How many new full-time employees will need to be hired?
b. What additional budget should be planned to cover the cost of the new employees?
c. What do you think would happen if these additional employees were not hired? Describe how this would affect the municipality and why it is best to hire these additional employees.
3) Your facility has purchased an air classification system with a fan that can generate an air flow rate in the system that goes up to 15 ft/sec. Your hammermill Hammermill shredder is able to provide a wastestream containing plastic that passes a 2 cm grate. The density of the plastic is 0.955 g/cm. The facility does not have the means to conduct a drop test, but as the site consultant, they want you to make your best estimate about whether the unit will separate out the plastic from the shredded waste. Show all work before you give your estimate.
4) Describe how the terms coding and switching are used in relation to MSW. Show how these terms apply to picking and hand- sorting operations, and describe best practices for each.
5) a. Describe how these separation technologies have evolved over the last decade. Include the factors that are driving the development and commercialization of these operations to be used in treating municipal solid waste.
b. In your opinion, which of the separation technologies in use today would qualify to be classified as best in class? State your criteria for what qualifies as best in class and state your reasons for your selection.