solid waste collection-finale

CHAPTER 8: Collection of Solid WasteBy: Ingrid L. Cortez

Collectiaon operation is considered from four aspects ::1)The types of collection services that are provided. 2)The types of collection systems and some of the equipment now labor requirements. 3)An analysis of collection systems, including the component relationships that can be used to used as well as the associated

quantify collection operation.

8-1)) Waste Collection

From low-rise detached dwellings

Collection Of Unseparated (Commingled) Waste1)Curb The home owner is responsible for placing the containers to be emptied at the curb on collection day and for returning the empty containers to 2) Alley storage location until the next collection. their Alley storage of containers used for solid waste is common.

8-1)) Waste Collection3)Setout-setback Containers are set out from the homowners's property and set back after being emptied by additional crews that work in conjunction with the collection crew responsible for loading the collection vehicle. 4)Setout Essentially the same with setoutsetback, except that the homeowner is responsible for returning the containers to their storage location.


Manual methods of residential waste collection:1) The direct lifting and carrying of loaded containers. 2) The rolling of loaded containers on their rims. 3) The use of small lifts for rolling loaded containers.Two frequently used containers:1) Large containers (tote containers)


From low- & medium-rise apartmentsCurbside collection service is common.

Maintainance staff is responsible for transporting the containers to the street for curbside collection by manual or mechaical means.

From high-rise apartmentsLarge containers are used to collect wastes from large apartment buildings.

The containers may

be emptied mechanically

using collection vehicles equipped with unloading mechanism or loaded containers may be hauled to an off-site location where contents are unloaded.


From commercial-industrial facilitiesBoth manual and mechanical means are used to collect wastes from commercial facilities.

Solid wastes from commercial establishments are collected in the late evening and eraly morning hours.

Waste collection is usually accomplished with 3 or 4 person crew:

Driver

(the

driver

remains

in

the

collection vehicle for reasons of safety)

2 or 3 collectors(loads the waste from the curbside into the collection vehicle)

8-1)) Waste CollectionCollection of wastes separated at the source Principal methods used for collection:

1)

Curbside collection Using conventional and specially designed collection vehicles.

2) Incidental curbside collection By charitable organization. By homeowners

3) Delivery


From residential curbside collectionSource separated recycables are collected separately from commingled wastes at the curbside, alley or commercial facility. The principal types of collection vehicle used: Standard collection vehicles Specialiized collection vehicles Closed body recycling trucks Recycling trailers Modified flatbed trucks Open-bin recycling trucks Compartmentalized trailers


From commercial facilitiesUsually collected by private haulers.

8-2)) Types Of Collection Systems,Equipment, And Personnel Requirements

Classified from sseveral points of view:

Mode of operation Equipment used Types of wastes collected

Classified according to their operation(from the book):

mode

of

Hauled Container System (HCS)

8-2)) Types Of Collection Systems,Equipment, And Personnel RequirementsContainers used for the storage of wastes are hauled to the disposal site, emptied, and returned either to their original location or some other location.

Advantages of Hauled Container System(HCS): Reduces handling time as well as the unsightly accumulation and unsanitary conditions assciated with the use of numerous smaller containers Their flexibility: containers of many different sizes and shapes are available for the collection of all types of wastes.


Personnel requirements:

Single collector is used Collector driver is responsible for driving the vehicle

Loading full containers onto the vehicle

Emptying

the

contents

of

the

containers at the disposal sites

Redepositing the empty containers


Three main types of Hauled Container System:

Hoist truck system(applicable only in limited number of cases)

For the collection of wastes by a collector who has a small operation and collects from a few backup points at which considerable amounts of wastes are generated.

For the collection of bulky items and industrial rubbish that are not suitable for collection with compaction vehicles.


Titl-frame Container

Uses tilt-frame loaded vehicles and large containers called drop or debris-boxes. Ideally suited for the collection of all types of solid waste and rubbish. Better for the collection of heavy rubbish: Sand Timber Metal scrap Often used for collection of deomolition wastes at construction sites.

Trash-trailer


Stationary Container System (SCS)Used for the collection of all types of wastes. Systems vary according to the type and quantity to be handled

Two main types: 1) Systems in which mechanically loaded collection vehicles are used 2) Systems in which manually loaded collection vehicles are used In which the wastes, containers, to collection vehicle bodies holding the wastes are transferred from a collection vehicle to a transfer or haul vehicle.

Transfer operation

8-2)) Types Of Collection Systems,Equipment, And Personnel RequirementsPersonnel requirements1) Will vary depending on whether the collection vehicle is loaded mechanically or manually 2) Labor requirements for mechanically loaded

vehicle are essentially the same container system 3) 2 helpers are used

as for hauled

4) A driver (often assists the helper in bringing loaded containers)

8-3)) Analysis Of CollectionSystems

Definition of termsFour unit operations involved in the collection of solid wastes:

Pickup (depends on the type of collection systemused)

For HCS -operated in the conventional mode --refers to the time spent driving to the next container after an empty container has been deposited -operated in the exchange mode --include the time required to pickup a loaded container and to redeposit the container at the next location after its contents have been emptied


For SCS-refer to the time spent loading the collection vehicle

Haul (depends also on the type of collectionsystem used)

For HCS-represents the time required to reach the location where the contents of the

container will be emptied.

For SCS

8-3)) Analysis Of CollectionSystems-refers to the time required to reach the location where the contents of the

collection vehicle will be emptied.

At-site

Refers to the time spent at the location where the contents of the container (HCS) or collection vehicle (SCS) are unloaded.


Off-route

Includes all time spent on acivities that are nonproductive from the point of view of the overall collection operation.

Necessary off-route time:1) Time spent ckecking in and out in the morning and at the end of the day 2) Time lost due to unavoidable congestion 3) Time spent on equipment repairs and maintainance

8-4)) Collection Routes

Must be laid out so that both the collectors and equipment are used effectively.Some heuristic guidelines that should be taken into consideration when laying out routes are as follows:1) Existing policies and regulations related to such items as the point of collection and frequency of collection must be identified. 2) Exisitng system characteristics such as crew size and vehicle types must be coordinated. 3) Whenever possible, route should be laid out so that they begin and end near arterial streets, using topogrophical

8-4)) Collection Routes4) In hilly area, route should start at the top of the grade and proceed downhill as the vehicle becomes loaded. 5) Routes should be laid out so that the last container to be collected on the route is located nearest to the disposal site. 6) Wastes generated at traffic-congested locations should be collected as early in the day as possible. 7) Sources at which extremely large quantities of wastes are generated should be serviced during the first parrt of the day. 8) scattered pickup points (where small quantities of solid wastes are genereated that receive the same collection

8-4)) Collection Routes

Layout of collection routesGeneral steps involved in establishing collection routes:1) Preparation of location maps showing pertinent data and information concerning the waste generation sources. 2) Data analysis and preparation of summary tables. 3) Preliminary layout of routes 4) Evaluation of preliminary routes and the

8-5)) Alternative Techniques ForAnalysis Of Collection Systems In the past and at present the design and operation of most solid waste collection system are based largely on experience and intuition. In an effort to operate existing systems and design new ones more efficiently, techniques and toolsuch as system analysis, operations research, system stimulation and systems and operations modelingdeveloped in related areas have from time to time been applied to the analysis of waste collection.

Thank