Solid waste management is generated from various human activities and which is normally disposed as useless and unwanted. Broadly, depending upon the type of building and built environment, it includes solid or semisolid domestic waste, such as sanitary waste, commercial wastes, office waste, catering and market waste and other non-resedential wastes, street sweepings, silt removed or collected from the surface drains, horticulture waste, construction and demolition waste, and treated biomedical waste.
Further, there may be industrial hazardous waste, biomedical waste and e-waste. The primary objective of solid waste management it is to collect, treat and dispose of solid wastes in an environmentally and socially satisfactory manner using the most economical means available.
Uncontrolled or poorly managed intermediate decomposition or organic components of solid waste can contaminate air, water and solid resources. Implementation of integrated solid waste management practices benefits substantially, both the public health and the quality of the environment.
Table of Contents
SOURCE OF GENERATION. SOLID WASTE MANAGEMENT
1. Domestic Waste. It is generated in residential units, and consist of food wastes, paper, carboard, plastics, textiles. leather, yard wastes, wood, glass, metals, ashes, special wastes, (e.g., bulky items, consumer electronics etc.), and household hazardous wastes.
2. Industrial Waste. It is generated in manufacturing units, fabrication plants, construction sites power and chemical plants, and consists of packaging, hazardous wastes, ashes, special wastes, wood, steel, concrete, dirt, etc.
3. Institutional and Commercial Waste. It is generated in schools, hospitals, prisons, government centres, stores, hotels, restaurants, markets, office buildings, etc. ; and consists of domestic wastes, paper, cardboard, plastic, glass, metals and hazardous wastes.
4. Horticulture waste. It is generated in landscaping, parks, orchards, dairies, and consists of street sweeping, landscape and tree trimmings etc.
BASED ON SUITABILITY FOR HANDLING AND DISPOSAL, SOLID WASTE MANAGEMENT
1. Garbage. Garbage is the term applied to animal and vegetable waste resulting from the handling, storage, sale, cooking and serving food. Such wastes contain putrescible organic matter, which produces strong odors and therefore attracts rats, flies, and other vermin. It requires immediate attention in its storage, handling and disposal.
2. Municipal Waste. Municipal waste includes waste resulting from municipal activities and services such as street wastes, dead animals, market wastes and abandoned vehicles.
3. Hazardous Wastes. Hazardous wastes may be defined as wastes of industrial, institutional or consumer origin. It includes ignitability, corrosivity, reactivity, or toxicity, whether alone or when in contact with other wastes or substances. Good waste management should ensure that hazardous wastes are stored, collected, transported and disposed of separately, preferably after suitable treatment to render them innocuous.
4. Bio-medical waste. Bio-medical waste is any waste, which is generated during the diagnosis, treatment or immunization of human beings or animals or in research A activities pertaining there to or in the production or testing of biologicals. It has been estimated that hospitals generate T biomedical waste at a rate of 1 kg per bed day. 75 to 90 percent of such solid waste is non-risk health care waste comparable to domestic waste. The remaining 10 to 25 % of health care waste is designated as bio-hazardous waste and is designated bio-medical waste.
5.Plastics. Plastic, due to their non-biodegradable nature, versatility is use and impact on environment, can be grouped under a different category of solid waste. Careless disposal of plastic, chokes drains, blocks the porosity of the soil, contaminates food stuff.
Efficient collection and disposal of domestic garbage from a building or activity area is of significant importance to public health and environmental sanitation and, therefore, an essential part of the built environment. Note. Single Plastic use banned from 2nd October 2019.
Solid Waste Management – Types, Methods, Challenges & Solutions for Solid Waste Management
STATUTORY RULES AND REGULATION FOR SOLID WASTE MANAGEMENT
1. The Environment (Protection) Act, 1986.
2. The Solid Waste Management Rules, 2016.
3. The Bio-Medical Waste Management rules, 2016.
4. The E-waste (Management) rules, 2016.
5. The Batteries (Management and Handling) rules, 2001.
6. The hazardous and other wastes (Management and Transboundary Movement) rules, 2016.
7. The Plastics Waste Management Rules, 2016.(May be amendment in 2019 being Single Plastic use banned from 2nd October 2019).
SOLID WASTE MANAGEMENT SYSTEMS
THE BASIC STAGES OF THE MUNICIPAL SOLID WASTE MANAGEMENT SYSTEM
The basic stages of the municipal solid waste management system include the following :
1. Waste sorting at source, collection and transportation.
2. Resource recovery through centralized sorting and recycling.
3. Resource recovery through waste processing, that is, recovery of energy.
4. Waste transformation without recovery.
THE FUNCTIONAL ELEMENTS OF MUNICIPAL SOLID WASTE MANAGEMENT SYSTEM
The functional elements of municipal solid waste management system include the following:
1. Waste Generation. Activity in which the waste gets generated as material no longer having any value.
2. Waste Handling, Sorting, Storage and Processing at site. Waste handling and sorting involves the activities associated with management of waste until they are placed in storage container for collection.
3. Collection. Gathering of solid wastes including transportation.
4. Transfer and Transport. Transfer of waste from smaller collection vehicle to longer transport equipment and subsequent transport of wastes over long distances to a processing or disposal site.
SORTING AT SOURCE
Sorting shall be planned based on the existing markets for recyclable materials. It is preferable to have coloured-bin system based on the usage of the facility and the types of the waste likely to be generated in the facility ( such as red, green, blue, yellow).
COMMON SORTING METHODS
Common Sorting Methods involve sorting into:
1. Dry recyclable materials, for example, glass, paper, plastics, metal etc.
2, Bio-waste and garden waste.
3. Bulky waste.
4. Hazardous material in household waste.
5. Construction and demolition waste.
6. Mingled MSW (mixed waste).
sorting not done at source, it is required to plan In case centralized sorting.
1. Hand sorting from a raised picking belt.
2. Mechanized sorting facilities using magnetic and electric field separation, density separation, etc.
3. Sorting at source normally recovers most of the recylable materials for reuse.
REFUSE CHUTE SYSTEM
1. Refuse chute system is a convenient and safe mode of transportation and collection of domestic solid waste from buildings exceeding 5 storeys from floors at different heights.
2. The refuse is received from the successive floor through the inlets located on the verticals system of pipes.
3. The system has got four functionally important components, such as
(a) The chutes.
(b) The inlet hopper.
(c) The collection chamber.
(d) The cleaning and disinfecting arrangement.
OPENING FOR FEEDING OF REFUSE CHUTE
1. Opening, with top or bottom hinged shutters with appropriate lockable latch, shall be provided for convenient accessing of the refuse chute by users.
2. The facilitates total building garbage collection at one single point and provides separate collection for dry and wet garbage.
3. Discharge end fire resistant door.
4. Vent shall be installed at roof level to remove foul smell and gases generated.
5. Chute should discharge to trolley directly.
6. Exhaust system with 25 to 35 air changes per hour.
7. Chute may be of masonry, RCC pipe, asbertos cement pipe or suitable non-corrosive material, preferably stainless steel.
8. Fire sprinklers shall be provided inside chute.
9. Necessary automation of the system may be planned to avoid malfunction by manual operation.
REFUSE COLLECTION CHAMBER
1. Collection chamber may be located in ground floor or basement level, provided appropriate arrangement is made for drainage of the collection pit by gravity flow to ensure its dryness.
2. The floor of the chamber shall be provided with drainage through a 100 mm diameter trap.
3. The collection chamber shall be provided with appropriate shutter to prevent access of scavenging animals like cattle, dogs, cats and rats.
REFUSE COLLECTION ROOM
1. The refuse collection room should be planned in ground or basement level with appropriate ventilation and proper drainage.
2. The room should have access for vehicle or trolley transfer of garbage.
DUMB-WAITER OR SERVICE LIFT
In high rise buildings with more than 5 storeys, electrically Operated dump-waiters may be used for carrying domestic garbage in packets or closed containers.
For handling of garbage by dump-waiters in a building, a garbage chamber shall have to be provided either at ground floor or basement level.
ASSESSMENT OF PER CAPITA WASTE QUANTITY
MUNICIPAL REFUSE GENERATION
The following municipal refuse generation.
1. Residential refuse : 0.3 to 0.6 kg/capita/day.
Commerical refuse : 0.1 to 0.2 kg/ capita/day.
3. Street sweepings : 0.05 to 0.2 kg/capita/day.
4. Institutional refuse : 0.05 to 0.2 kg/capita/day.
Out of the total solid waste generated, 40 % may be taken as organic waste and 60 % as inorganic waste.
These generation rates are subject to considerable site specific factors and are required to be supported by field data. The waste contains a high percentage of ash and fine earth.
The calorific value of Indian solid waste varies between 800 and 1000 kcal/kg and the density varies between 300
and 500 kg/m3.
OTHER THAN MUNICIPAL SOLID WASTE
The following types of waste may be generated in urban centres
1. Industrial Waste. Hazardous and non-hazardous, waste from industrial area.
2. Bio-medical Waste. Waste from hospitals, slaughter houses etc.
3. Thermal Power Plant Waste. Fly ash from coal-based electricity generating plant.
4. Effluent Treatment Plant Waste. Sludge from sewagetreatment plants and industrial effluent treatment plants.
5. Other Wastes. Special waste from non-conforming areas,
Garbage collected at one location may be treated for organic portion, and inorganic portion shall be handed over to vendors carrying out recycling organic waste generated in building/premises/community/environment may be treated and reused as manure.
Biological or thermal treatment of waste can result in recovery of the products such as compost or energy.
Biological treatment involves using micro organisms to decompose the biodegradable components of waste. Two types of processes used are :
1. Aerobic Processes. It may comprise composting, aerated static pile composting and in-vessel composting, vermi-culture, etc. In the aerobic process the utilizable product is compost.
2. Anaerobic Processes. It may comprise low-solids anaerobic digestion (wet process), high solids anaerobic digestion ( dry process) and combined processes. In the anaerobic process the utilizable product is methane
gas ( for energy recovery).
Composting. Decomposition and stabilization of organic waste matter is a natural phenomenon, composting is an organized method of producing compost manure by adopting this natural phenomenon.
1. Manual Composting. It is an anaerobic method conventionally carried out in pits. Initially the waste is anaerobically stabilized in pits where alternate layers ofsolid waste and right soil are laid. The pit is completely filled.
2. Mechanical Composting. Mechanical process are preferred where higher labour costs and limitations of space exits. It is the process using a combination of aerobic and anaerobic decomposition in enclosed containers. The organic wet and dry waste is separated and shredder is used to homogenize. The materials and blenders are used under controlled temperature and bio-enzyme addition in closed containers.
3. Vermi Composting Vermi-compost treatment shall be provided to the organic waste in composting pits located in shade. The pit shall be used to receive the garbage in a predetermined (periodic) cyclic order. The gross area of the composting pits may be about 0.1 m per person.
The compost may be removed from the bottom of the compost pit after intervals of 3 to 6 months. The compost so made may be used in appropriate horticultural and related applications.
Thermal treatment involves conversion of waste into gaseous, liquid and solid conversion products with concurrent or subsequent release of heat energy.
Three types of systems can be adopted.
1. Combustion Systems (Incinerators). Thermal processing with excess amount of air.
2. Pyrolysis Systems. Thermal processing in complete absence of oxygen (low temperature).
3. Gasification Systems. Thermal processing with less amount of air ( High temperature).
Disposal of waste on lands identified for the purpose is typical of this method of waste disposal. Landfills in which municipal waste is placed are designated as “MSW landfills “.
The main considerations in respect of landfill sites are:
1. Specifications for landfill sites.
2. Site selection.
3. Facilities at site.
4. Specification of land filling
Improper land fill generally impacts the environment in the following ways.
1. Ground water contamination by the leachate generated by the waste dump.
2. Surface water contamination by the run-off from the waste dump.
3. Bad odour, pests, rodents and wind-blown litter in and around the waste dump.
4. Generation of inflammable gas ( for example, methane) with in the waste dump.
5. Bird menace above the waste dump which affects flight of aircraft.
6. Fires within the waste dump.
7. Erosion and stability problems relating to slopes of the waste dump.
8. Epidemics through stray animals.
9. Acidity to surrounding soil.
10. Release of green house gas.
MUNICIPAL SOLID WASTE MANAGEMENTS GENERATION
The typical type of wastes generated may be as follows
SLAUGHTER HOUSE WASTE
Slaughtering of animals generates consisting on non-edible offal (lungs, large intestines, etc), Stomach/intestinal contents, dung, sludge from waste water and bones, etc. These have to be disposed of by methods like rendering/controlled incineration/burial/composting/anaerobic digestion, etc. The estimated waste generation may be as per the following.
The waste generated from medical activities can be hazardous, toxic and even lethal because of their high potential for disease transmission.
The components of bio-medical waste include.
Human anatomical waste ( tissues, organs, body parts, etc).
2. Animal waste ( as above, generated during research/ experimentation, from veterinary hospitals, etc)
3. Microbiology and biotechnology waste, such as laboratory cultures, micro organisms, human and animal cell cultures, toxins etc.
4. Waste sharps, such as hypodermic needle, syrings, scalpels, broken glass, etc.
5. Discarded medicines and cytotoxic drugs.
6. Soiled waste, such as dressing, bandages, plaster casts, material contaminated with blood, etc.
7. Solid waste ( disposable items like tubes, catcheters, etc., excluding sharps).
8. Liquid waste generated from any of the infected areas.
9. Incineration ash.
10. Chemical waste.
The estimated generation of total waste is 1.5 kg/bed and the estimated generation of bio-medical waste at 25 percent of total waste generation.
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