Module 8 Flashcards
The fraction
of MSW produced in domestic households is called ________.
refuse
The components of refuse are _____ or ________ and _______.
garbage, food waste, trash
We have observed more than __ human diseases associated with solid waste disposal sites, and there is little doubt that improper solid waste disposal is a health hazard.
20
These are the means by which disease organisms are transmitted, and water, air, and food may all be vectors.
disease vectors
The two most important disease vectors related to solid wastes are _____ and ______.
rats, flies
Flies are such prolific breeders that 70,000 flies can be produced in 1 ft3 of garbage, and carry many diseases like __________.
bacillary dysentery
The plagues of the __________ were directly associated with the rat populations.
Middle Ages
__________ is also threatened by infiltration of leachate from MSW disposal into groundwater, and particularly into drinking water supplies.
Public health
It is formed when rainwater collects in landfills, pits, waste ponds, or waste lagoons, and stays in contact with waste material long enough to leach out and dissolve some of its chemical and biochemical constituents.
leachate
It may be a major groundwater and surface water contaminant, particularly where there is heavy rainfall and rapid percolation through the soil.
leachate
Techniques the Quantities of MSW generated in a Community may be Estimated
input analysis, secondary data analysis, output analysis
This technique estimates MSW based on use of a number of products; highly inaccurate except in small and isolated communities.
input analysis
This technique may be used to estimate solid waste production by some empirical relationship; inherently inaccurate and may have no general application.
secondary data analysis
This technique is by weighing the refuse dumped at the disposal sites, either with truck scales or with portable wheeled scales.
output analysis
Fees for use of the dump which depends on the weight dumped, requiring refuse to be weighed in any case.
tipping fees
Daily weight of refuse varies with the _______ and the ______.
day of the week, week of the year
Moisture content can vary between _______ that’s why weather conditions also affect refuse weight.
15% to 30%
If every truckload cannot be weighed, these are used to estimate the total quantity from sample truckload weights.
statistical methods
Characteristics of site and MSW wherein Refuse Management depends
- gross composition
- moisture content
- particle size
- chemical composition
- density
may be the most important characteristic affecting MSW disposal, or the recovery of materials and energy from refuse
gross composition
Refuse composition is expressed either “_________” or “_________,” since moisture transfer takes place during the disposal process and thereby changes the weights of the various fractions of refuse.
as generated, as disposed
The moisture content of MSW may vary between 15 and 30%, and is usually about ___.
20%
Moisture is measured by drying a sample at ____ (170°F) for 24 hours.
77°C
It is particularly important in refuse processing for resource recovery.
particle size distribution
It is an expensive part of waste management, and many new devices and methods have been proposed in order to cut costs.
collection
It reduce the amount of garbage in refuse; are so ubiquitous that in most community’s garbage collection is needed only once a week; put an extra load on the wastewater treatment plant.
garbage grinders
These have been installed in some small communities, mostly in Sweden and Japan; refuse is ground at the residence and sucked through underground lines.
pneumatic pipes
It can reduce collection and MSW disposal costs and thus reduce local taxes, but only if every household has one; uses special high-strength bags, so that the operating cost is also a consideration.
kitchen garbage compactors
These are part of many urban refuse collection systems; located at various points in a city, to which collection trucks bring the refuse.
transfer stations
These are often provided by the community and are widely used for transfer of refuse from the household to the collection truck.
cans on wheels
They suffer higher lost-time accident rates than other municipal or industrial workers.
garbage collection workers
These may result in significant cost saving as well as increased effectiveness.
route optimization
Route optimization was first addressed by mathematician ______ in ______.
Leonard Euler, 1736
Where was Leonard Euler asked to design a parade route?
city of Konigsberg in East Prussia
Only Two Realistic Options for Disposal
oceans and on land
This term was first used for the method of disposal employed in the burial of waste ammunition and other material after WW2, and the concept of burying refuse was used by several Midwestern communities.
sanitary landfill
open dump vs sanitary landfills:
simply places to deposit wastes
open dumps
open dump vs sanitary landfills:
engineered operations
sanitary landfills
open dump vs sanitary landfills:
designed and operated according to acceptable standards
sanitary landfills
It is the compaction of refuse in a lined pit and covering of the compacted refuse with an earthen cover.
sanitary landfilling
The landfill is built up in units called ____.
cells
The daily cover in landfills is between ___ to ___ inches thick depending on soil composition, and a final cover of at least _____ feet thick is used to close the landfill.
6, 12, 2
Numerous stages involved in sanitary landfilling operations
siting, design, operation, closing
It is rapidly becoming the most difficult stage of the process of landfilling since few people wish to have landfills in their neighborhoods.
siting of landfills
Consideration:
Rapid runoff will lessen mosquito problems, but proximity to streams
or well supplies may result in water pollution.
drainage
consideration:
It is preferable that the landfill be downwind from any nearby community.
wind
consideration:
A small site with limited capacity is generally not acceptable since finding a new site entails considerable difficulty.
size
consideration:
The production of leachate from the landfill is influenced by the weather.
rainfall patterns
consideration:
Can the soil be excavated and used as cover?
soil type
consideration:
The bottom of the landfill must be substantially above the highest expected groundwater elevation.
depth of the water table
consideration:
The landfill must be proximate to wastewater treatment facilities
treatment of leachate
consideration:
All landfills attract birds to some extent, and are therefore not compatible with airport siting.
proximity to airports
consideration:
Can the area be used for private or public use after the landfilling operation is complete?
ultimate use
In the absence of oxygen, __________ steadily degrades the organic material to more stable forms.
anaerobic decomposition
The liquid produced during decomposition, as well as water that seeps through the groundcover and works its way out of the refuse.
leachate
The water entering a landfill must equal the water flowing out of the landfill, or leachate.
water balance
second by-product of a landfill
gas
stages of gas production in landfills
- aerobic stage
- anaerobic decomposition stage
- anaerobic methane production stage
- steady-state condition stage
escape vents; kept lit and the gas is burned off as it is formed
tiki torches
biological method of waste treatment
landfill operation
must include methods for the recovery and treatment of the leachate produced by the decomposing refuse, and the venting or use of the landfill gas
landfill design
