SOLID WASTE Lecture 3 Collection and Transport (copy)

Waste collection system

A ________________ delivers the inputs to the SWM system.

remove waste streams ;
origin ;
intermediate treatment unit ;
final disposal sites

The function of waste collection is to ___________ from its ______ (e.g. household, commercial shop, industrial park, construction site) and ship the collected waste to the ___________ toward the _________.

collector ;
gather ;
container

The role of the _______ is to _____ this material together into one
________ .

Phase 1: House to Can
Phase 2: Can to Truck
Phase 3: Truck from House to House
Phase 4: Truck Routing
Phase 5: Truck to Disposal

The process of refuse collection should be thought of as a multiphase process, and it is possible to define at least five separate phases:

Individual homeowner

_________ must transfer whatever is considered waste to the refuse can, which may be inside or outside the home.

house-to-can phase

The _______ has received almost no attention or concern by researchers or government because the efficiencies and conveniences gained here are personal and not communal.

tax funds

Communities in the United States use ______ to operate the solid waste collection and disposal system, or they charge for the service just as they charge for water consumption and wastewater disposal.

Volume-Based Fee System

To pay for solid waste collection and specify the containers that must be used

30, 60, or 90-gallon (110-, 230-, and 340-liter) cans.

In a volume- based fee system, residents are offered cans in three sizes—such as ____

size of can used

The fee for refuse service is based on the ____

4000

Over ______ communities have adopted volume-based rates for solid waste collection.

25 to 35%

The EPA reports typical reduction of ______ for communities that have gone to volume-based rates.

Weight-Based Fee System.

Other communities are taking the volume-based approach one step further by weighing every can and charging by actual weight, called the _______

can to the truck ;
backyard collection

The second phase is the movement of the refuse ________. This is usually done by the collection crew, called ___________.

Curbside collection

If the can is moved to the street by the waste generator or the home occupant, the system is called _______

Solid waste collection ;
America

With all of the improvements in collection technology, __________ is still one of the most hazardous jobs in _______.

solid waste collectors ;
three ;
coal miners

________ had the highest injury rate of any vocation— ______ times higher than the injury rate for _______.

U.S. Department of Labor's Occupational Safety and Health Administration (OSHA) Statistics Department ;
40% ;
strains ;
bruises ;
fractures

A survey by the _________________ found that fully ______of the solid waste workers had missed time during the preceding year due to various injuries, including _______, _______, and _______.

Packers

The traditional trucks used for residential and commercial refuse
collection are rear-loaded and covered compactors called __________.

Wheel weight

The truck size is often limited not by its ability to store refuse but by
its ________.

Side loaders

To reduce injuries and to speed up collection, some solid waste collection companies are changing from rear loaders to ___________

Waste wheelers

Two revolutionary changes during the 1990s had a great impact on both the cost of collection as well as the injury rate of the collectors.
The first is wide acceptance of the can-on-wheels idea, known as _________.

Hydraulic hoists

The collection vehicles are equipped with __________that are used to empty the contents into the truck

Semi-automated collection

The collectors do not come in to contact with the refuse, avoiding dangerous materials that can cut or bruise. This system, referred to as __________, typically requires a driver and one or more collectors.

can snatcher ;
fully automated collection

A further development in solid waste collection technology is the ________, trucks equipped with long arms that reach out, grab a can, and lift it into the back of the truck. Such systems, called __________, are especially useful where the street layout includes alleys behind the houses

Plastic bags.

The second revolutionary development in solid waste collection is the widespread use of __________

higher ;
more

Once the refuse is in the truck, it is compacted as the truck moves from house to house. The ______ the compaction ratio, the ______ refuse the truck can carry before it has to make a trip to the landfill.

Micro Routing

The routing of a vehicle within its assigned collection zone is often called __________

1736

The problem of designing a route so as to eliminate all deadheading was actually addressed as early as ______.

Leonhard Euler

The problem of designing a route so as to eliminate all dead heading was actually addressed as early as 1736. The brilliant mathematician, ________, was asked to design a route for a parade across the seven bridges of Konigsberg, a city in eastern Prussia, such that the parade would not cross the same bridge twice but would end at the starting point.

1. Routes should not overlap, should be compact, and should not be fragmented.
2. The starting point should be as close to the truck garage as possible.
3. Heavily traveled streets should be avoided during rush hours.
4. One-way streets that cannot be traversed in one line should be looped from the upper end of the street.
5. Dead-end streets should be collected when on the right side of the street.
6. On hills, collection should proceed downhill so that the truck can coast.
7. Clockwise turns around blocks should be used whenever possible.
8. Long, straight paths should be routed before looping clockwise.
9. For certain block patterns, standard paths, as shown in Figure 3-11, should be used.
10. U-turns can be avoided by never leaving one two-way street as the only access and exit to the node.

The following sets of rules apply to microrouting.

location of the final destination ;
materials recovery facility ;
disposal site ;
transfer station

The fifth phase of the collection system involves the ___________ (_____________, ________, or ________).

Commercial solid waste

__________ is almost always collected with dumpsters, which are large steel containers that are commonly lifted overhead by the collection truck.

Hazardous or dangerous materials

________can be transferred to the truck and could cause dangerous situations in the landfill or combustor. At the landfill, the refuse in the full truck is then pushed out.

Roll-off containers

____________ are commonly used in construction sites.

Producers

_______ are being urged to take responsibility for the products they produce to ensure that the material is either recyclable or that it uses post-consumer recycled material

Commingled collection of recyclable materials

The recyclables are not separated into specific items but placed all into one container, this is called _______________

Blue bag system

Another option for collecting commingled recyclable material is the ____________, in which the recyclables are placed in a special blue bag provided to or by each customer.

Yard waste

________ also typically is placed in a separate container.

Third Truck

A ______ is needed to collect the yard waste and take this material to a mulching or composting operation.

Experience and mathematical modeling

Both _____________ suggest that collection of commingled recyclables on a per-ton basis is more expensive than the collection of mixed refuse. As would be expected, the cost gain on a per-ton basis decreases with both participation rate and the total amount of recyclables collected. If the income from the sale of recycled materials is taken into account, however, the cost of collecting recycled items is not significantly different from the cost of collecting mixed, unsorted refuse.

Everett et al.

_______ have developed a model that estimates the cost of collecting partially separated (commingled) recyclables at curbside.14 The model estimates the time to collect such waste and to sort it at the truck into various individual components. Three variables in the model are travel time, sorting time, and waiting time

• Fraction of refuse components diverted from the landfill, measured in tons per week.

• Fraction of households participating in the program; participation can be defined in many ways, such as having set out recyclables at least once a month

• Fraction of households participating on any given week

• Profit from the sale of recyclables, measured in dollars per week.

• These metrics provide insight into the effectiveness and sustainability of the recycling program, helping to assess its impact on waste reduction, community engagement, and financial viability.

To estimate the success of a curbside recycling program, several factors need to be considered:

Litter

________ is a special type of Municipal Solid Waste (MSW).

Litter

It is distinct from other types of MSW in that it is solid waste that is not deposited into proper receptacles.

Collection of litter

The ____ is of secondary importance to a community because it does not represent a critical public service like police and fire protection, water treatment, and the collection of refuse from residences and commercial establishments.

• Items by actual count
• Total weight of litter
• Volume of litter
• Visible items by actual count

One major problem with any litter data analysis is that the reports fail to specify the guidelines used in the collection and identification of litter and seldom specify the way in which the percentages of the various components were calculated.

• Count as one item all pieces larger than 2.5 cm (1 in.). This count includes removable tabs from beverage cans.

• Do not count rocks, dirt, or animal droppings

• Count as one item all pieces of any item clearly belonging together, such as a broken bottle. Otherwise, count each piece of glass, newspaper and so on, singly

• Do not count small, readily decomposable material, such as apple cores

• For roadside litter surveys, measure all items within the officially designated right of way.

• Empty liquids out of all bottles and cans before collecting them.

Due to the problem of not having a standard counting technique, the following guidelines for conducting litter studies are suggested:

Litter

_______ theoretically can be controlled by cognitive, social, and technological means.

environmental ethic ;
integrated waste management

Americans have an ______ and recognize the need for __________.

Recycling

The limits to _______ are still unknown

effectively ;
efficiently collect

One of the major objectives in solid waste engineering is to _______ and ________ all of the materials people no longer want.

Solid waste engineers

It is important that ___________ properly design collection systems.

Garbage collection

Finally, it is important to recognize that ________ is still a labor-intensive job

• The capacity of each disposal site is limited

• The amount of refuse disposed of must equal the amount generated

• The collection route centroids cannot act as disposal site, or the total amount of refuse hauled from each collection area must be greater than or equal to zero

• Total cost = Hauling Cost + Disposal Cost

Several requirements must be met (Constraints in an Optimization Model):