Solid Waste Eng

MEE 5901, Advanced Solid Waste Management 1

UNIT II STUDY GUIDE

Solid Waste Characteristics,

Quantities, and Collection

Course Learning Outcomes for Unit II Upon completion of this unit, students should be able to:

1. Identify municipal solid waste and its characteristics. 2. Identify the composition of different types of solid waste. 3. Explain the heat values of refuse and how they are expressed. 4. Analyze the different methods of solid waste collection. 5. Describe truck routing and the use of transfer stations. 6. Analyze litter collection methods and where they are more beneficial.

Unit Lesson Unit II consists of Chapters 2 and 3 - Municipal Solid Waste Characteristics and Quantities and Collection. This unit involves concepts as well as numerical computations. This lecture will focus on computations. Chapter 2 Example 2-1 introduces you to different types of household waste that are produced. The example computes what percentage of waste can be diverted from the landfill as well as the percentage of recyclables as a fraction of the landfilled materials. Example 2-2 computes the moisture content of a residential waste. The values for moisture, such as "6" for paper is 6% moisture obtained from Table 2-1. "w" is wet weight and "d" is dry weight. Example 2-3; A calorimeter is a method for determining the heat of combustion. The example shows that the original refuse sample produces 4000 Btu/lb when burned. If moisture is removed from the sample before burning, then the sample can produce 4444 Btu/lb when burned. Further, if neither ash production nor moisture is included in energy production, then 5714 Btu/lb of heat are available. Examples 2-4 and 2-5 explain the computation of statistical means. You should practice working the problems at the end of the chapter. Answers to select questions are provided below.

Problem 2-1: Landfill will fill in 30 days

Problem 2-3: 2.8 lb/in2

Problem 2-13: Density of loose refuse is 206 lb/yd3

Volume occupied by 100 lb of loose refuse is 0.49 yd3

Density of baled refuse is 767 lb/yd3

Volume occupied by 100 lb of baled refuse is 0.13 yd3

Problem 2-14: 21.6% water

Problem 2-17: 5270 Btu/lb

Problem 2-18: 4890 Btu/lb

Problem 2-19: 10 ft-lb

Reading Assignment Chapter 2: Municipal Solid Waste Characteristics and Quantities Chapter 3: Collection

MEE 5901, Advanced Solid Waste Management 2

Chapter 3 Example 3-1 shows the value of compacting refuse to reduce the volume of garbage set out for collection. Examples 3-2 and 3-3 show calculations for how many customers can be served before filling a garbage truck. Examples 3-4 and 3-5 explain how to compute the number of collection vehicles required. Page 85 presents equations for how much time is required to walk down a street to collect recyclables. At the top of page 85, note that the distance between stops "A" is in meters (not feet). A stop is where the worker stops to pick up a container of recyclables. Examples 3-6 and 3-7 describe litter surveys which show the demographic that is more likely to litter. Do you think someone is more likely to litter if they are 18 and younger or 19 and over? Please work a few of the problems at the end of the chapter. Here are some answers.

Problem 3-5: 38 minutes one-way haul time

Problem 3-7: Both people walk both sides; they don't split up.

Thus, total time per side = 29.5 minutes, or 59 minutes total.

Problem 3-22: 1. 18 or younger than

2. No trash cans, then

3. Area already littered

Many of the other problems require multiple assumptions, so, multiple valid answers are possible.