Separation and Processing

Issues in this lecture: 1- Storage and Processing at the Source 2- Separation and processing of solid waste components. 3- Transformation processes.

Storage and Processing at the Source 1- Storage and Processing at the Source 2- Separation and processing of solid waste components. 3- Transformation processes.

. Handling and Separation at the Source Handling refers to activities associated with MSW before they are placed in a collection container May also include handling the collection container to and from the collection point Source recovery is one of the most effective ways to recycle: aluminum cans, newspaper, plastic soda and milk bottles.

. Handling and Separation at the Source Handling refers to activities associated with MSW before they are placed in a collection container May also include handling the collection container to and from the collection point Source recovery is one of the most effective ways to recycle: aluminum cans, newspaper, plastic soda and milk bottles.

Storage of SW at the Source Effects of Storage Putrefaction - Microbial decomposition via bacteria and fungi leading to vermin and odors. Adsorption of Fluids - If more than a week, the water will become equally distributed, primarily moisture from food and garden material moving into the paper. Contamination - A small volume of paint had great potential to contaminate a great deal of plastic, an argument for source separation of recyclables.

Storage of SW at the Source Types of Storage Containers For residential containers, manually collected, the max. weight should be 40-65lbs as not injure the collector. 32 gallons galvanized or plastic is the most common. Temporary and disposable containers such as cardboard boxes, plastic bags and paper bags are common. A problem with these is that animals are attracted by the food and tear them open and spread the material around.

Storage of SW at the Source Types of Storage Containers Low rise - trend towards 1 man collection crews with vehicles with mechanical, articulated arms and 90 gallon containers, (75-120) Low and medium rise - Demsey dumsters, portable or not, galvanized or plastic High rise - more proned to have processing equipment: compaction, shredding, baling and in the old days incineration.

Storage of SW at the Source Types of Storage Containers Container Locations: side or rear of house, alleys, common location identified for that purpose. Public health and aesthetics - Potential for odors and vermin. Randy and his maggots....

Storage of SW at the Source Processing at Dwellings Insinkeration of food - No significant decrease in the weight or volume of the MSW, see problem 6-4. Separation - very effective if you can engender meaningful participation. Compaction - individual units under the counter, collection and processing by large units. Potentially counterproductive if the wastes are to sorted at a MRF; also, compaction may foster contamination.

Storage of SW at the Source Composting The biological conversion of the biodegradable organic fraction of the MSW resulting in a volume reduction and producing a useful by-product Isolate a 3ft square area with chicken wire and dump the yard wastes. Food wastes may be stirred into the mix if odor and vermin problems can be obviated.

Storage of SW at the Source Composting Water and turn occasionally, once/week. Perhaps ready to use after 1 year, put in at top, take out at bottom. Produces a humus-like material which is a soil conditioner, not a fertilizer.

Break even analysis

Break even analysis A transfer station becomes economically feasible when it reduces the cost of transporting wate to a haul disposal or transfer site as compared to hauling the waste directly in collection vehicle. Direct haul and transfer haul costs calculated for various distances to identify the point at which the costs are equal(break-even distance).

Break even analysis Any distance greater than the calculated break-even distance indicates that transfer haul for that distance is more economical than direct haul. The break-even distance is significantly impacted by travel time which is a function of transportation network from the end of the collection route to the disposal or transfer site.

Break even analysis