Solid Waste Management 12/4/2018 SWM

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What are solid wastes? All wastes happening from human and animal activities Normally solid Discarded as useless or unwanted Urban community, Agricultural, Industrial and Mineral wastes 12/4/2018 SWM

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Materials Flow and Waste Generation Raw Materials Manufacturing Secondary manufacturing Processing and recovery Consumer Final disposal Residual debris Residual waste material Raw materials, products, and recovered materials Waste materials 12/4/2018 SWM

Solid Waste Management The discipline associated with the control of generation, storage, collection, transfer and transport, processing, and disposal of solid wastes in a manner that is in accord with the best principles of public health, economics, engineering, conservation, aesthetics, and other environmental considerations, and that is also responsive to public attitudes. 12/4/2018 SWM

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Solid Waste Management (continued) Complex interdisciplinary relationships among political science, city and regional planning, geography, economics, public health, sociology, demography, communications, and conservation, as well as engineering and materials science 12/4/2018 SWM

Interrelationships between the functional elements in a solid waste management system Waste generation Collection Separation and processing and transformation of solid waste Transfer and transport Disposal Waste handling, separation, storage, and processing at the source 12/4/2018 SWM

Waste handling, separation, storage, and processing at the source Handling and separation involve the activities associated with management of wastes until they are placed in storage containers for collection. The best place to separate waste materials for reuse and recycling is at the source of generation (currently, also for hazardous wastes). 12/4/2018 SWM

Collection Include the gathering and the transport of these materials In large cities, where the haul distance to the point of disposal is greater than 15 miles, the haul may have significant economic implications. Transfer and transport facilities are normally used where long distances are involved 12/4/2018 SWM

Separation and processing and transformation of solid waste Separated wastes are recovered by three means, i.e. curbside collection, drop off, and buy back centres. Processing includes; e.g. the separation of bulky items, size reduction by shredding, separation of ferrous metals using magnets. Transformation processes are used to reduce the volume and weight of waste requiring disposal and to recover conversion products and energy. 12/4/2018 SWM

Transfer and Transport The transfer of wastes from the smaller collection vehicle to the larger transport equipment The subsequent transport of the wastes, usually over long distances, to a processing or disposal site 12/4/2018 SWM

Disposal Landfilling or landspreading is the ultimate fate of all solid wastes. A modern sanitary landfill is not a dump; it is an engineered facility used for disposing of solid wastes without creating nuisances or hazards to public health or safety. EIA is required for all new landfill sites. 12/4/2018 SWM

Integrated Solid Waste Management “The selection and application of suitable techniques, technologies, and management programs to achieve specific waste management objectives and goals” 12/4/2018 SWM

Hierarchy of Integrated Solid Waste Management Source reduction: the most effective way to reduce waste quantity Recycling: involves the separation and collection; the preparation for reuse, reprocessing; the reuse, reprocessing Waste transformation: the physical, chemical, or biological alteration of wastes Landfilling: the least desirable but indispensable mean for dealing with wastes 12/4/2018 SWM

Sources, Types, and Composition of Industrial Solid Wastes 12/4/2018 SWM

Sources of Solid Wastes Residential Commercial Institutional Construction and Demolition Municipal services Treatment plant sites Industrial Agricultural Municipal solid waste (MSW) 12/4/2018 SWM

Plastic Materials Polyethylene terephthalate (PETE/1) High-density polyethylene (HDPE/2) Polyvinyl chloride (PVC/3) Low-density polyethylene (LDPE/4) Polypropylene (PP/5) Polystyrene (PS/6) Other multilayered plastic materials (7) 12/4/2018 SWM

Hazardous Wastes “Wastes or combinations of wastes that pose a substantial present or potential hazard to human health or living organisms” 12/4/2018 SWM

Industrial Solid Waste Excluding Process Wastes 12/4/2018 SWM

Industrial Solid Waste Excluding Process Wastes (cont.) 12/4/2018 SWM

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Determination of the Composition of MSW in the Field Residential MSW: 200 lb (90.72kg) of samples is considered enough. To obtain a sample, the load is first quartered. One part is then selected for additional quartering until a sample size of about 200 lb (90.72kg) is obtained. Commercial and Industrial MSW: Samples need to be taken directly from the source, not from a mixed waste load in a collection vehicle. 12/4/2018 SWM

Physical, Chemical, and Biological Properties of MSW 12/4/2018 SWM

Physical Properties of MSW Specific weight Moisture content Particle size and size distribution Field capacity Compacted waste porosity 12/4/2018 SWM

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Chemical Properties of MSW The four most important properties if solid wastes are to be used as fuel are; Proximate analysis Fusing point of ash Ultimate analysis (major elements) Energy content The major and trace elements are required if the MSW is to be composted or used as feedstock 12/4/2018 SWM

Proximate Analysis Moisture (moisture lost after heated at 105°C for 1 hr.) Volatile combustible matter (additional loss of weight after ignited at 950°C) Fixed carbon (combustible residue after volatile matter removal) Ash (weight of residue after combustion) 12/4/2018 SWM

Ultimate Analysis of Solid Waste Components Involves the determination of the percent C, H, O, N, S, and ash Due to the chlorinated compounds emission, the determination of halogens is often included. Moreover, they are used to define the proper mix of waste materials to achieve suitable C/N ratios for biological conversion processes. 12/4/2018 SWM

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Energy Content of Solid Waste Components Determined by; A full scale boiler as a calorimeter A laboratory bomb calorimeter Calculation, if the elemental composition is known 12/4/2018 SWM

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Physical Transformations Component separation Mechanical volume reduction Mechanical size reduction 12/4/2018 SWM

Chemical Transformations Combustion (chemical oxidation) Pyrolysis Gasification 12/4/2018 SWM

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Biological Transformations Aerobic Composting Anaerobic Digestion 12/4/2018 SWM

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Waste Handling and Separation, Storage, and Processing at The Source 12/4/2018 SWM

Waste Handling and Separation at Commercial and Industrial Facilities Relatively large containers mounted on rollers are utilised before being emptied. Solid wastes from industrial facilities are handled in the same way as those from the commercial facilities. 12/4/2018 SWM

Storage of Solid Wastes at The Source Effects of Storage on Waste Components; biological decomposition, absorption of fluids, contamination of waste components Types of Containers 12/4/2018 SWM

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Processing of Solid Wastes at the Source Grinding of Food Wastes Separation of Wastes Compaction Composting Combustion 12/4/2018 SWM

Collection of Solid Waste 12/4/2018 SWM

Introduction Difficulties arise from the complexity of the sources of solid wastes. Due to the high costs of fuel and labour, ~50-70% of total money spent for collection, transportation, and disposal in 1992 was used on the collection phase. 12/4/2018 SWM

Definition of Collection “Gathering or picking up of solid wastes, including the hauling to and unloading at the site” 12/4/2018 SWM

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Types of Collection Systems Hauled Container Systems (HCS) Stationary Container Systems (SCS) 12/4/2018 SWM

HCS: Conventional Mode 12/4/2018 SWM

HCS: Exchange Container Mode 12/4/2018 SWM

Hauled Container Systems (HCS) Pros Suited for the removal of wastes from high rate of generation sources because relatively large containers are used Reduce handling time, unsightly accumulations and unsanitary conditions Require only one truck and driver to complete the collection cycle Cons Each container requires a round trip to the disposal site (or transfer point) Container size and utilisation are of great economic importance 12/4/2018 SWM

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Personnel Requirements for HCS Usually, a single collector-driver is used A driver and helper should be used, in some cases, for safety reasons or where hazardous wastes are to be handled 12/4/2018 SWM

SCS 12/4/2018 SWM

Stationary Container Systems (SCS) Can be used for the collection of all types of wastes There are two main types: mechanically loaded and manually loaded Internal compaction mechanisms are widely use thanks to their economical advantages 12/4/2018 SWM

Transfer Operations Can be economical when; Small, manually loaded collection vehicles are used for residential wastes and long haul distances are involved Extremely large quantities of wastes must be hauled over long distances One transfer station can be used by a number of collection vehicles 12/4/2018 SWM

Personnel Requirements for SCS Mechanically The same as for HCS A driver and two helpers are used if the containers are at the inaccessible locations, e.g. congested downtown commercial area Manually The number of collectors varies from 1 to 3 12/4/2018 SWM

Separation and Processing and Transformation of Solid Waste 12/4/2018 SWM

Uses for recovered materials Direct reuse Raw materials for remanufacturing and reprocessing Feedstock for biological and chemical conversion products Fuel source Land reclamation 12/4/2018 SWM

Unit Operations Used For The Separation and Processing of Waste Materials To modify the physical characteristics of the waste To remove specific components and contaminants To process and prepare the separated materials for subsequent uses 12/4/2018 SWM

Shredders (a) hammermill (b) fail mill (c) shear shredder Trommel 12/4/2018 SWM

Baler Magnetic Separators Can Crusher 12/4/2018 SWM

Facilities for Handling, Moving, and Storing Waste Materials 12/4/2018 SWM

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Waste Transformation Through Combustion 12/4/2018 SWM

Waste Transformation through Aerobic Composting 12/4/2018 SWM

Objectives of Composting To stabilise the biodegradable organic materials To destroy pathogens, insect eggs, etc. To retain the maximum nutrient (N,P,K) To produce fertilizer 12/4/2018 SWM

Static Pile Composting Windrow Composting Static Pile Composting 12/4/2018 SWM

Transfer and Transport 12/4/2018 SWM

The Need for Transfer Operations Direct hauling is not feasible Illegal dumping due to the excessive haul distances Disposal sites are far from the collection routes more than 10 mi Use of small-capacity collection vehicles (< 20 yd3) Low-density residential service area 12/4/2018 SWM

The Need for Transfer Operations (continued) The use of HCS with small containers for commercial sources waste The use of hydraulic or pneumatic collection systems Transfer operation is an integral part of the operation of a MRF 12/4/2018 SWM

Types of Transfer Station Direct-load Storage-load Storing capacity 1-3 days Combined direct- and discharge-load 12/4/2018 SWM

Disposal of Solid Wastes and Residual Matter 12/4/2018 SWM

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Development and completion of a landfill Preparation of the site for landfilling The placement of wastes Postclosure management 12/4/2018 SWM

Concerns with the Landfilling of Solid Wastes The uncontrolled release of landfill gases The impact of landfill gases as the greenhouse gases The uncontrolled release of leachate The breeding and harbouring of disease vectors The adverse effects of the trace gases arising from the hazardous materials 12/4/2018 SWM

“The goal for the design and operation of a modern landfill is to eliminate or minimize the impacts associated with these concerns.” 12/4/2018 SWM

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