MUNICIPAL SOLID WASTE MANAGEMENT UNIT – II ONSITE STORAGE AND PROCESSING Part A 1. Name the materials used for containers to collect solid waste? The materials are galvanized sheet, wooden boxes, paper bags, cardboard boxes, plastics. 2. What are the various onsite processing to collect solid waste? Onsite means these functions are concerned with solid waste at the place where the waste is generated. For residential waste this means at home in the household. Onsite handling is the very first step in waste management. It involves individual family members, households and communities, all of whom need to know how to handle waste properly, at this level. Handling means the separation of wastes into their different types. 3. What is onsite segregation of solid waste and its necessity? Waste segregation means dividing waste into dry and wet. Dry waste includes wood and related products, metals and glass. Wet waste, typically refers to organic waste usually generated by eating establishments and are heavy in weight due to dampness. Waste can also be segregated on basis of biodegradable or nonbiodegradable waste. Segregation is easy to dispose the waste. 4. List the objective of going for onsite processing of solid waste The main objective of onsite processing of solid waste is to confirm the applicability of maximum processing capability in area of waste management. 5. List the various advantage of waste segregation? In solid waste management a primary health benefit is the control of vermin that spread disease. By consolidating residential and some types of commercial wastes, then using appropriate disposal technology habitat is reduced, or nearly eliminated, for rodents and insects that otherwise pose a public health risk. Another health benefit is the control of disposal methods that prevent in discriminate burning or burial methods that could pose long term and acute health risks. 6. Define onsite handling Onsite means these functions are concerned with solid waste at the place where the waste is generated. For residential waste this means at home in the household. Onsite handling is the very first step in waste management. It involves individual family members, households and communities all of whom need to know how to handle waste properly at this level. Handling means the separation of wastes into their different types so they can be dealt with in the most appropriate way, for example, separating putrescible waste
for composting. The benefits of appropriate onsite handling include reducing the volume of waste for final disposal and recovering usable materials. 7. What are the factors that must be considered on onsite storage? Storage containers go through a detailed inspection ensuring all storage containers are wind and water tight. Storage containers can be certified cargo worth and CSC plated for international movement if required. 8. What are the equipments used for onsite handling of solid waste in residential and commercial sources? Landfills, composting, incineration, digesters, disposers, collectors, remote and closed coupled pulpers, mini pulping systems, compostable waste shredder, food waste dehydrator. 9. What is chute? Chute is defined as a channel down while falling materials are guided. 10. Write short notes on sorting? The decomposable materials in refuse are isolated from glass, metal and other inorganic items through sorting and separating operations. These are carried out mechanically, using differences in such physical characteristics of the refuse as size, density, and magnetic properties. Shredding or pulverizing reduces the size of the waste articles, resulting in a uniform mass of materials. It is accomplished with hammer mills and rotary shredders. 11. Give the common methods of handling of solid waste in high rise apartment. Solid waste management is mandatory in apartments. Onsite solid waste management is installed by some builders and developers for apartments in past few years. Apartments with solid waste management units can give manure manufactured from unit to farmers and nursery in and around their neighbourhood. 12. Write short notes on container location? The occupant of every dwelling unit shall place all solid waste to be collected in proper solid waste containers. The owner shall maintain such solid waste containers and the surrounding area in a clean, neat and sanitary condition at all times. 13. List any two factors influencing onsite storage. Storage containers go through a detailed inspection ensuring all storage containers are wind and water tight. Storage containers can be certified cargo worthy and CSC plated for international movement if required. 14. Write short notes on container locations The occupant of every dwelling unit shall place all solid waste to be collected in proper solid waste containers. The owner shall maintain such solid waste containers and the surrounding area in a clean, neat and sanitary condition at all tiems. 15. What is hydropulpery?
It is nothing but the process of using pulk galvaniser to compact the solid waste. Main disadvantage of using these system is expensive 16. Define shredding? Shredding or pulverizing reduces the size of the waste articles, resulting in a uniform mass of material. It is accomplished with hammer mills and rotary shredders. 17. List any four factors that should be considered in evaluating the onsite processing equipment? Mechanical collection systems have been developed to reduce collection cost. The system requires use of a special container, truck container pick up equipment, and replacement of the container. For an economic point of view, such equipment are most unlikely to be applied in Ethiopian situation. 18. Write about compaction? Compaction is the process of compacting waste. Compaction means to compress, condense or consolidate. It is often used to reduce the size of waste material. Garbage compactors and waste collection vehicles compress waste so that more of it can be stored in the same space. Waste is compacted again, more thoroughly, at the landfill to conserve valuable airspace and to extend the landfills life span. A side effect of this is that important items, like evidence in a crime, may be difficult to recover from the garbage. 19. What is composting? Another method of treating municipal solid waste is composting, a biological process in which the organic portion of refuse is allowed to decompose under carefully controlled conditions. Microbes metabolize the organic waste material and reduce its volume by as much as 50%. The stabilized product is called compost or humus. It resembles potting soil in texture and odour and may be used as a soil conditioner or mulch. 20. List the advantage and disadvantages associated with home separators? Advantages: Greater privacy Homes typically increase in value. Your costs are predictable and more stable than renting because they are ideally based on a fixed-rate mortgage. The interest and property tax portion of your mortage payment is a tax deduction. There’s pride in homeownership, which also closely ties you to your community. Disadvantages: Homeownership is a long term financial commitment. You’re responsible for all maintenance on your home. This can include inexpensive repairs like fixing a broken toilet to complex and costly repairs like replacing a furnace.
Owing a home ties you to your community, making it more difficult to suddenly pick up and leave a location. Although mortgage payments are usually fixed, they’re generally higher than rent payments.
21. List out the methods for the primary collection of waste stored at various sources of waste generation. 22. What are the various stages at which sorting can takes place in the waste stream? 23. What are the text storage options for Indian refuse? 24. What are the major recoverable materials present in the MSW? 25. List the key components of the receiving area of an MSW processing facility? 26. What are the advantages to using a shredder for MSW processing in a MRF? What are the disadvantages? 27. What is the purpose of source of reduction? 28. What are the factors that have to be considered while evaluating the residential waste containers? 29. List out different purposes onsite processing. 30. What is meant by mechanical collection of solid wastes? 31. List out the factors causing variation of solid waste generation. 32. What is recovery and recycling of solid waste? List out the operations involved in recycling? 33. List out the functional elements for solid waste management? 34. What is the importance of waste stream assessment? 35. List out some domestic hazardous waste? 36. What are options for selection of container? 37. What are the impacts of house hold waste storage in tropical country? 38. What is the legal requirement in India regarding onsite storage and collection of MSW? 39. Enumerate the biological properties of solid waste 40. When will you recommend a hauled container system? 41. When will you prefer stationary container system? PART B 1. What are the careful considerations for a design of an efficient storage container? 2. What is magnetic separation of solid waste? Explain process for magnetic separation? What are the factors influence the effectiveness of magnetic separation? 3. Explain why handling and storage of solid waste varies in urban and rural areas? 4. Explain on-site segregation techniques suitable for Indian refuge and justify it? 5. What are the factors that should be considered in evaluating onsite processing equipment? Explain the various equipments used for magnetic separation? 6. Explain the difference between compaction and size reduction and their importance in solid waste management. Explain the types, mode of action, and applications of equipments used for size reduction and component separation in detail. 7. Explain the types of waste collection systems based on their mode of operation with a neat sketch.
8. Explain the types of vehicle and the requirement of vehicle for transportation of solid waste. 9. List out the factors influencing equipment selection for on-site processing of solid wastes. 10. Describe the on-site processing of solid wastes in medium and high rise buildings. 11. Explain the different on-site process on solid waste. 12. Identify the activities responsible for successful implementation of collection system. What are the rules to be kept in mind while designing the collection route? 13. Explain the types, mode of action, and application of equipment used for component separation. 14. Describe the various methods of sorting the solid waste. 15. Discuss the ways of sorting the solid waste at various sources of generation 16. Explain in detail the different types of collection systems based on the mode of operation 17. List out measures to be taken by the local bodies towards segregation of recyclable waste. 18. What are the considerations in the selection of material and capacity of storage containers? 19. What is meant by proximate analysis and ultimate analysis of solid waste?
UNIT 2 – ONSITE STORAGE AND PROCESSING ON-SITE STORAGE: The handling, storage and processing of solid wastes at the source before they are collected is the second of the six functional elements in the solid waste management system. ON- SITE HANDLING: Onsite handling refers to the activities associated with the handling of solid wastes until they are placed in the containers used for their storage before collection. ONSITE STORAGE Factors that must be considered in the onsite storage of solid waste includes The type of container to be used The container location Public health and aesthetics The collection methods to be used CONTAINERS To a large extent, the types and capacities of the containers used depend on the characteristics of the solid wastes to be collected, the collection frequency, and the space
available for the placement of containers. The types and capacities of containers now commonly used for onsite storage. LOW RISE DWELLINGS: Because solid wastes are collected manually, from most residential and low rise detached dwellings, the containers should be light enough to be handled easily by one collector when full. Injuries to collectors have resulted from handling containers that were loaded to heavily. In general, the upper weight limit should be between 40 – 65 lb. The 30gal galvanized metal or plastic container has proved to be the least expensive means of storage for low-rise dwellings. MATERIALS USED FOR STORAGE: The choice of container materials depends on the preference of the individual homeowner. Galvanized metal containers tend to noisy when being emptied and, in time, can be damaged so that a proper lid seal cannot be achieved. Although less noisy in handling, some containers constructed of plastic materials tend to crack under exposure to the ultraviolet rays of the sun and to freezing temperatures but the more expensive plastic containers apparently do not present these problems. Temporary and disposable containers are commonly used when curb service is provided and the homeowner is responsible for placing accumulated wastes on the curb for collection. Paper bags cardboard boxes, plastic containers and bags and wooden boxes are routinely used as temporary & disposal containers. In low rise apartments, a number of different storage containers have been used. The two most common types are 1. Individual plastic or galvanized metal containers 2. Large portable or fixed containers Where apartments are grouped in close proximity, containers assigned to the individual apartments are often located in a common area. Although individual containers are often used in some low-rise apartment buildings, the most common practise is to use on or more large containers for a group of apartments. Often, the container enclosures are covered, in most locations the containers are equipped with. MEDIUM AND HIGH RISE APARTMENTS Where solid waste chutes are available, separate storage containers are not used. In some older medium and high rise apartments without chutes, wastes are stored in containers on the premises between collections. INDIVIDUAL APARTMENTS Large open-top containers Enclosed storage containers or disposable bags used in conjunction with stationary compactors Containers equipped with a self contained compaction mechanism Special containers used in conjunction with processing equipment. ON SITE SEGREGATION OF SOLID WASTES
Municipal solid waste is being generated in ever increasing volumes in the urban areas. The schematic diagram describes how municipal solid waste is segregated and where it can be used MSW
ONSITE PROCESSING OF SOLID WASTES Onsite processing methods are 1. Grinding 2. Sorting 3. Compaction 4. Shredding or pulping 5. Composting 6. Incineration And are all onsite processing methods used to i. Reduce the volume ii. Alter the physical form iii. Recover usable materials from solid wastes Onsite processing as applied to residential sources and large commercial and industrials sources. Onsite processing of solid waste by waste sources Source Person responsible Residential low Residents, tenants
Operation & facilities Grinding, sorting, compaction,
rise Medium & high rise Commercial Open areas
Tenants, building maintenance Sanitorial services Owners- park operators, plant operators, owners workers
incineration Grinding, sorting, compaction, incineration, shredding, hydropulping Sorting, compaction Compaction, incineration, dewatering facilities
LOW RISE DWELLINGS: The most common onsite processing operation used at low rise detached residential dwellings include grinding, sorting, compaction, composting & incineration. Grinding, in the past 20 years the use of home grinders has gained such wide acceptance that, in some areas nearly all the new homes are equipped with them. Home grinders are used primarily for wastes from the cooking and serving of foods, and they cannot be used for large bones or other bulky items. GRINDING Functionally, grinders render the material that passes through them suitable for transport through the sewer system. Because the organic material added to sewage has resulted in overloading many treatment facilities, it has been necessary, in some communities. In terms of the collection operation, the use of home grinders does not have a significant impact on the volume of solid waste, collected. SORTING The sorting or separation of waste paper, aluminium cans, and glass by hand at the household is one of the most positive ways to achieve the recovery and reuse of materials once the waste is sorted into separate containers, the biggest problem facing the homeowner is what to do with the wastes until they are collected or taken to a local recycling centre. COMPACTION Within the past few years, a number of small compactors designed for home use have appeared on the market, manufactures claims for these units in terms of the compaction ratio usually are based on the compaction of loose paper and card board. Although it is possible to reduce the original volume of waste placed in them by up to 70%. They can be used only for a small proportion of the wastes actually generated. The effect of the use of home compactors on the volume of wastes collected is illustrated. Component Weight lb Density lbft3 Volume ft3 Food wastes 9.5 15 0.53 Paper 43.1 5.1 8.45 Cardboard 6.5 6.2 1.05 Plastics 1.8 4 0.45 The use of home compactors may also be counterproductive from the stand point of subsequent processing operations. If the wastes are to be separated mechanically into components, the compacted wastes will have to be broken up again before sorting. Also by compacting the wastes may become so saturated with the liquids present in the food wastes that the recovery of paper or other components may not be feasible.
COMPOSTING In the 1970s home composting as a means of recycling organic materials increased in popularity. It is an effective way of reducing the volume and altering the physical composition of solid wastes while at the same time producing a useful by-product. A variety of methods are used, depending on the amount of space available and the waste to be composted. INCINERATION Until recently, home incineration burning combustible materials in fire places and burning rubbish in crude backyards incinerators- was a common practice. Backyard incineration is now banned in many parts of the country. The effect of the elimination of backyard burning on the quantity of wastes The design of small outdoor and indoor incinerators has improved the simplest outdoor incinerator consists of a metal drum with holes punched near the bottom. The more elaborate units are lined with refractory brick and are equipped with cast-iron grates and small chimneys. Some indoor incinerators are provided with an auxiliary fuel source. The appearance of the better indoor incinerator is similar to that of other household appliances, such as water heaters. The impact of the use of home incinerators on disposal varies depending on the methods used for the disposal of municipal solid wastes. In the case of municipal solid wastes. In the case of municipal incineration the widespread use of home incinerators may necessitate the use of auxiliary fuels, special designs, or operating procedures. SHREDDING OR PULPING: Shredding and pulping are alternative processing operations that have been used both in conjunction with the previous methods and by themselves, for reducing the volume of wastes that must be handled. Where shredding is used alone without the addiction of water, the volume of wastes has often been observed to increases. Wastes from the various floors are discharged into a chute that discharges into a pulper tank. In the pulper tank, waste is added and maintained at the proper level. The wastes are shredded into a pulp by the teeth in the propeller plate located at the bottom of the pulper tank. Non pulpable components, such as metals and glass are discharged into a collection chamber after being reduced in size. The pulp slurry passes through a sizing ring where an oversized material is not allowed to pass out of the pulper. The slurry is then discharged to the dewatering press where it is picked up by a helical screw, water is extracted and the semidry pulp is discharged into a container. The extracted water is returned to the pulper tank. Excess water containing some residual pulp usually is discharged to the waste water collection system. ONSITE SEPARATION OF SOLID WASTE Component separation is a necessary operation in the recovery of resources from solid wastes and where energy and conversion products are to be recovered from processed wastes the required separation may be accomplished manually or mechanically. When manual separation is used, pre-processing of the wastes is not required.
Some of the separation methods are o Hand sorting o Air separation HANDLING AND SEPARATION AT THE SOURCE
Handling refers to activities associated with MSW before they are planned 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, aluminium cans, newspaper, plastic soda and milk bottles.
LOW RISE Single family detached and attached Single family detached Separate recyclables at the MRF, not at the home Variety of storage containers and mixed waste, plastic bags, 32 gallon galvanized or plastic, cardboard boxes LOW AND MEDIUM RISE Basement storage by residents and moving of the container by maintenance personal Large outdoor containers, located in special areas that are emptied mechanically by the collection tank HIGH RISE APARTMENTS Posters pick up the waste at the apartment door. Wasters are taken to the SW area by tenants Vacuum transport systems have been used most notably at Disney world. COMMERCIAL AND INDUSTRIAL FACILITIES Commercial- removed from work area by wheeled containers or blanked wrapped and transported via the service area to a disposal/processing area. Compaction would not be unusual. Industrial area- may be more susceptible to the profit motive e.g. can order employees to recycle cans. VARIOUS ISSUES PERTAINING TO PUBLIC HEALTH AND ECONOMIC ASPECTS OF STORAGE OF MSW Constraints regarding storage of water and source:
Lack of public awareness. Motivation and education Lack of civil sense. Bad habits of the people to litter the wastes. Non co-operation from the households and traders Lack of powers to levy spot fines Lack of stringent panel provisions Long distance between two community bins Lack of funds
Public and health asthetics on storage of solid waste The problem developed due to storage of waste and source are: Emission of odours Leachate generation Breeding of flies, bacteria and etc. To overcome these problems we have to do follow the below things; Use of closed plastic containers Periodic washing Proper sanitation facilities Periodic removal of biodegradable materials
