Date post: | 18-Dec-2015 |
Category: |
Documents |
Upload: | rudolph-hart |
View: | 221 times |
Download: | 1 times |
Prepared by: Ahmed Sawalha
1. Sources of Solid Wastes
2. Types of Solid Waste
3. Composition of Solid Waste
4. Determination of the Composition of MSW in the Field 5. Types of Materials Recovered from MSW
6. Future Changes in Waste Composition
Sources of solid wastes in a community are: • Residential • Commercial • Institutional • Construction and Demolition • Municipal Services • Treatment Plant Sites • Industrial • Agricultural
MSW includes all the community waste with the exception of industrial process waste and agriculture wastes
It is important to define the various types of solid wastes that are generated and the sources to design and operate of the functional elements associated with the management of solid waste
Table 1 provides the sources and types of solid waste within a community
Source Typical facilities, activities, locations where
wastes are generated
Types of solid wastes
Residential Single and multifamily dwellings
Food wastes, paper, cardboard, plastics, textiles, leather, yard wastes, wood, glass, metals, ashes, special wastes (e.g., bulky items, consumer electronics, white goods, batteries, oil, tires), and household hazardous wastes
Industrial Light and heavy manufacturing, fabrication, construction sites, power and chemical plants
Industrial process waste, scrap materials, etc. Non - industrial waste including food wastes, construction and demolition wastes, rubbish, ashes , hazardous wastes, ashes, special wastes
Table 1: Sources and Types of Solid Wastes within a Community
Source Typical facilities, activities, locations where wastes are generated
Types of solid wastes
Commercial Stores, hotels, restaurants, markets, office buildings, etc.
Paper, cardboard, plastics, wood, food wastes, glass, metals, special wastes, hazardous wastes
Institutional Schools, hospitals, prisons, government centers
Same as commercial
Construction and Demolition New construction sites, road repair, renovation sites, demolition of buildings, broken pavement
Wood, steel, concrete, dirt, etc.
Table 1: Sources and Types of Solid Wastes within a Community (Cont’d)
Table 1: Sources and Types of Solid Wastes within a Community (Cont’d)
Source Typical facilities, activities, locations where wastes are
generated
Types of solid wastes
Municipal Services (excluding treatment facilities)
Street cleaning, landscaping, parks, beaches, other recreational areas, water and wastewater treatment plants
Street sweepings; landscape and tree trimmings; general wastes from parks, beaches, and other recreational areas; sludge
Agricultural Field and row crops, orchards, vineyards, dairies, feedlots, farms, etc.
Spoiled food wastes, agricultural wastes, rubbish, hazardous waste.
Organic (Combustible)
Inorganic (non-combustible) Putrescible
Recyclable
Hazardous Infectious
Composition is the term used to describe the individual components that make up a solid waste stream and their relative distribution
Information on the composition of solid wastes is important in evaluating equipment needs, systems and management programme and plans
The residential and commercial portion makes up about 50 to 75 percent of total MSW generated in a community
The actual percentage distribution will depend on The extent of construction and demolition
activities The extent of the municipal services provided The types of water and wastewater treatment
process that are used
Composition is the term used to describe the individual components that make up a solid waste stream and their relative distribution
Information on the composition of solid wastes is important in evaluating equipment needs, systems and management programme and plans
The residential and commercial portion makes up about 50 to 75 percent of total MSW generated in a community.
The actual percentage distribution will depend on The extent of construction and demolition
activities The extent of the municipal services provided The types of water and wastewater treatment
process that are used.
ComponentPercent by Weight Moisture percent
Range Typical Range Typical
Organic
Food wastes 6 – 26 15 50 – 80 70
Paper 25 – 45 40 4 – 10 6
Cardboard 3 – 15 4 4 – 8 5
Plastics 2 – 8 3 1 – 4 2
Textiles 0 – 4 2 6 – 15 10
Rubber 0 – 2 0.5 1 – 4 2
Leather 0 – 2 0.5 8 – 12 10
Yard wastes 0 – 20 12 30 – 80 60
Wood 1 – 4 2 15 – 40 20
Misc. organics
Inorganics
Glass 4 – 16 8 1 – 4 2
Tin cans 2 – 8 6 2 – 4 3
Aluminum 0 – 1 1 2 – 4 2
Other metal 1 – 4 2 2 – 6 3
Dirt, ash etc 0 – 10 4 6 – 12 8
The percentage distribution values for the components in MSW vary with Location Season economic conditions population Social behavior Climate Market for waste materials Other factor
Because the heterogeneous nature of solid wastes, determination of the composition is not an easy task
More generalized field procedures based on common sense and random sampling technique have evolved for determining composition
The procedure for residential MSW can be summarized as following
The load is first quartered One part is then selected for additional quartering
unit a sample size of about 200 lb is obtained It is important to maintain the integrity of each
selected quarter regardless of the odor or physical decay
make sure that all the components are measured
The field procedure for component identification for commercial and industrial waste involves the analysis of representative waste samples taken directly from the source, not from a mixed waste load in a collection vehicle. Due to the fact that these wastes are so variable.
Aluminum Paper Plastics Glass Ferrous Metals (Iron and Steel) Nonferrous waste Yard waste collected separately Construction and demolition wastes
Recycling is the best way to solve solid waste management problem. This process exists in all cities . However, the recycling system differs from developing countries and developed countries .
Developed countries have well organized source separation and recycling system while in the developing countries the system of recycling is not effective because it is still in the hands of informal sectores
Developing Countries Have Recycling System Starting From Curbside Collection System. Separate Colored Collections Bins are Provided to Deposit Separate Waste Material
These Sorting Facilities are Well Organized and Materials are Separated for Further Processing
Separation of Recyclable and Placing Separately
T
These Scavengers Collect the Recyclables and Separate in their Own Premises
Recyclables Collected from Scavengers are Deposited in One Place
In terms of solid waste management planning, knowledge of future trends in the composition of solid waste and quantities are of great importance.
Food Waste The quantity of residential food waste collected has
changed significantly over the years as a result of technical advances and change in public health
Food processing and packaging industry and the use of kitchen food waste grinders have effected the quantity of food waste
The percentage of food waste, by weight, has decreased from about 14 percent in the early 1960s to about 9 percent in 1992.
Paper and Cardboard The percentage of paper and cardboard found in MSW has
increased greatly over the past half century , rising from about 20 percent in the early 1940s to about 40 percent in 1992
if the U.S. postal rate for bulk mail were increased to first class mail, a significant reduction would occur in the amount of paper collected for disposal
Yard Wastes The percentage of yard waste has also increased significantly,
due primarily to passage of laws that prohibit burning of yard wastes.
By weight, yard waste currently accounts for about 16 to 24 percent of the waste stream
Environmental conditions such as droughts have also affected the quantities of yard wastes collected in certain locations
Plastics The percentage of plastics in solid waste has increased
significantly during the past 50 years
the use of plastics has increased from almost non-measurable quantities in the early 1940s to between 7 and 8 percent, by weight, in 1992
It is anticipated the use of plastic will continue to increase, but at a slower rate than during the past 25 years