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Waste disposal and management

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neeru02

This document discusses different types of solid wastes generated from various human activities and their sources. It provides data on the annual quantities of various solid wastes generated. It then describes different methods for managing solid wastes - sanitary landfilling, incineration, composting, recycling, and their advantages and limitations. Specific techniques for managing hazardous wastes and biomedical wastes are also outlined.

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- Neeraja A
 Solid wastes are the wastes arising from human and animal activities, that are normally solid and that are discarded as useless or unwanted materials
 Solid wasted include crockery, bottles, plastics, and other wastes thrown out as garbage.  Old Automobile spares, machines, etc,.  Building material wastes, settled solid components of sewage, dead animals, chemicals, paints from industries and crop residue from agriculture, pathogenic materials from hospitals, etc,.
SOURCES QUANTITY [Mt/annum] Municipal wastes 25-39 Agricultural residues 350 Cattle manure 210 Poultry manure 3.3 Out of 30 Mt/annum of municipal wastes, 8.5 Mt/annum comes out from nine metropolitan cities only. About 60-80% of these wastes are collectes on daily basis and rest is left to deacy.
Waste disposal and management
SOLID WATES SANITARY LANDFILL INCINERATION COMPOSTING RECYCLING
 A sanitary landfill is designed to reduce the amount of waste that leaks out in the environment.  The landfill is lined with clay to prevent leaching, methane produced by rotting of garbage in the dump may need to be vented to prevent possible fire or explosion.  The methane thus collected is used for electricity production.  The water leaching must be treated before reaching ground water.
Waste disposal and management
 Composting is a common practice of solid waste disposal in rural areas for the production of manure and biogas.  Composting is a process biological degradation or breakdown of organic matter under aerobic conditions.  The organic compost resulting from this process makes a nutrient rich soil amendment that aids water retention, slow soil erosion and improves crop yeilds.
Waste disposal and management
 The most quick & convenient method.  It reduces the amount of wastes that goes to the landfill,  They can also generate electricity from the heat generated by burning the garbage.  They are designed to burn thousands of tonnes of wastes per day.  However, it causes pollution adding fly ash, particulates and gases.  Wastes do not completely burn even at high temp (1,300°C). The residues are taken to landfill or sea to dispose.
Waste disposal and management
 Recycling of wastes helps in reducing pollution.  The materials that can be recycled collecte from the wastes are paper, cloth, metals, glass, rubber & plastics.  Other recyclable materials are cars, electronic goods such as computers, etc.
Waste disposal and management
 Any discarded material containing substances known to be toxic, carcinogenic, mutagenic or teratogenic to humans or other life forms; ignitable, explosive, or highly reactive is called hazardous wastes.  The wastes containing certain chemicals, metals and pathogenic organismsare also hazardous in nature.  These can damage the environment as well as endanger life at low cocentrations.
Waste disposal and management
 Hazardous waste management costs heavily therefore waste reduction should be incorported. 1. Toxic substances should be replaced by non-toxic substances. 2. Transferring the waste to some other industry where they can be utilized in some other ways. 3. Substituting the raw materials. 4. Recycling and reprocessing.
1) Thermal treatment 2) Chemical treatment 3) Physical treatment 4) Biological treatment
 Wastes must be heated to about 1200ºC for a sufficient period to complete destruction.  The ash resulting is reduced in volume upto 90% and the rest is stored in a landfill.  Plenty of oxygen is added for quick and complete burn.  Gaseous hydrocarbons are not consumed in the incinerator.  Scrubbers and precipitators remove minerals, particulate and other pollutants from the stack.
 Chemical treatment can transform toxic substances to non-toxic substances.  Neutralization, removal of metals/halogens & oxidation are few chemical processes.  Neutralization is followed in treating acidic or alkaline wastes.  Acidic wastes is neutralized by slaked lime Ca(OH)2, caustic soda (NaOH) or soda ash (Na2CO3).  Alkaline wastes are neutralized by mineral acid. eg. H2SO4 or HCl or with CO2.
 Removal of metals is done by ion exchange, membrane technique, reverse osmosis, electrodialysis, activated carbon absorption & precipitation.
 Physical treatments tie up or isolate substances.  Charcoal or resins filters absorb toxins.  Distillation separates hazardous components from aqueous solutions.  Precipitation and immobilization in ceramics, glass, or cement isolate toxins from the environment.
 Specific bacterial strains capable of degrading the wastes breaking down into CO2 & water are used.  By using recombinant DNA technology new microorganisms could be developed to feed on specific hazardous wastes.
Waste disposal and management
 Finally after treatment the hazardous wastes are disposed by the following methods. 1. Landfilling 2. Incineration 3. Deep well injection
Guidelines:  The site must be located higher than 100 year flood plain.  Impermeable lines be installed to collect the leachates.  Any leachate that is collected should be pumped out and treated.  Monitoring wells are required to check the quality of ground waters in the area.
Common wastes which can be disposed are:  Sludge from cyanide bearing wastes,  Sludge from phenol treatment,  Heavy metal containing wastes,  Ash from various treatment categories of wastes,  Discarded containers.
 A high temperature thermal oxidation, which converts wastes into gases and combustible substances.  This method is used to dispose combustible liquids and solid hazardous wastes and pesticides and petroleum refineries wastes.  It destroys pathogens & decomposes organic compounds into CO2, H2O, etc.,  This process is adopted for wastes that cannot be recycled or reused.
 Developed in late 1800’s.  A specific kind of geological formation must be needed for disposal.  The formation must be deep, providing space & sandwiched between impermeable layers of rock.  This method is very expensive and risky, hence not followed in routine practice.
Waste disposal and management
Waste disposal and management
 Biomedical wastes are wastes which are generated during diagnosis, treatment or immunization or in the research and testing biologicals.  Hospital wastes are needles, syringes, surgical gloves, bottles, blood and body fluid, placenta and other body parts, radioactive substances, cytotoxic drugs, chemicals, etc.,
 AIDS,  Hepatitis,  Meningitis,  Gastroenteric, respiratory, ocular, genital & skin infections  Anthrax, etc.,
 The wastes are disposed by burning it in incinerator at 1200ºC .  Other methods by using autoclave, microwave, hydro wave, etc.,  Wastes burnt below 1200ºC release toxic pollutants like dioxins, furans which are carcinogenic & suppress immune and reproductive systems
 Launching mass awareness campaign through electronic and print media to inform clinics and dispensaries to undertake proper management of biomedical wastes.  Training of staffs towards proper segregation of biomedical wastes is also necessary.
Waste disposal and management

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Waste disposal and management

  • 2.  Solid wastes are the wastes arising from human and animal activities, that are normally solid and that are discarded as useless or unwanted materials
  • 3.  Solid wasted include crockery, bottles, plastics, and other wastes thrown out as garbage.  Old Automobile spares, machines, etc,.  Building material wastes, settled solid components of sewage, dead animals, chemicals, paints from industries and crop residue from agriculture, pathogenic materials from hospitals, etc,.
  • 4. SOURCES QUANTITY [Mt/annum] Municipal wastes 25-39 Agricultural residues 350 Cattle manure 210 Poultry manure 3.3 Out of 30 Mt/annum of municipal wastes, 8.5 Mt/annum comes out from nine metropolitan cities only. About 60-80% of these wastes are collectes on daily basis and rest is left to deacy.
  • 7.  A sanitary landfill is designed to reduce the amount of waste that leaks out in the environment.  The landfill is lined with clay to prevent leaching, methane produced by rotting of garbage in the dump may need to be vented to prevent possible fire or explosion.  The methane thus collected is used for electricity production.  The water leaching must be treated before reaching ground water.
  • 9.  Composting is a common practice of solid waste disposal in rural areas for the production of manure and biogas.  Composting is a process biological degradation or breakdown of organic matter under aerobic conditions.  The organic compost resulting from this process makes a nutrient rich soil amendment that aids water retention, slow soil erosion and improves crop yeilds.
  • 11.  The most quick & convenient method.  It reduces the amount of wastes that goes to the landfill,  They can also generate electricity from the heat generated by burning the garbage.  They are designed to burn thousands of tonnes of wastes per day.  However, it causes pollution adding fly ash, particulates and gases.  Wastes do not completely burn even at high temp (1,300°C). The residues are taken to landfill or sea to dispose.
  • 13.  Recycling of wastes helps in reducing pollution.  The materials that can be recycled collecte from the wastes are paper, cloth, metals, glass, rubber & plastics.  Other recyclable materials are cars, electronic goods such as computers, etc.
  • 15.  Any discarded material containing substances known to be toxic, carcinogenic, mutagenic or teratogenic to humans or other life forms; ignitable, explosive, or highly reactive is called hazardous wastes.  The wastes containing certain chemicals, metals and pathogenic organismsare also hazardous in nature.  These can damage the environment as well as endanger life at low cocentrations.
  • 17.  Hazardous waste management costs heavily therefore waste reduction should be incorported. 1. Toxic substances should be replaced by non-toxic substances. 2. Transferring the waste to some other industry where they can be utilized in some other ways. 3. Substituting the raw materials. 4. Recycling and reprocessing.
  • 18. 1) Thermal treatment 2) Chemical treatment 3) Physical treatment 4) Biological treatment
  • 19.  Wastes must be heated to about 1200ºC for a sufficient period to complete destruction.  The ash resulting is reduced in volume upto 90% and the rest is stored in a landfill.  Plenty of oxygen is added for quick and complete burn.  Gaseous hydrocarbons are not consumed in the incinerator.  Scrubbers and precipitators remove minerals, particulate and other pollutants from the stack.
  • 20.  Chemical treatment can transform toxic substances to non-toxic substances.  Neutralization, removal of metals/halogens & oxidation are few chemical processes.  Neutralization is followed in treating acidic or alkaline wastes.  Acidic wastes is neutralized by slaked lime Ca(OH)2, caustic soda (NaOH) or soda ash (Na2CO3).  Alkaline wastes are neutralized by mineral acid. eg. H2SO4 or HCl or with CO2.
  • 21.  Removal of metals is done by ion exchange, membrane technique, reverse osmosis, electrodialysis, activated carbon absorption & precipitation.
  • 22.  Physical treatments tie up or isolate substances.  Charcoal or resins filters absorb toxins.  Distillation separates hazardous components from aqueous solutions.  Precipitation and immobilization in ceramics, glass, or cement isolate toxins from the environment.
  • 23.  Specific bacterial strains capable of degrading the wastes breaking down into CO2 & water are used.  By using recombinant DNA technology new microorganisms could be developed to feed on specific hazardous wastes.
  • 25.  Finally after treatment the hazardous wastes are disposed by the following methods. 1. Landfilling 2. Incineration 3. Deep well injection
  • 26. Guidelines:  The site must be located higher than 100 year flood plain.  Impermeable lines be installed to collect the leachates.  Any leachate that is collected should be pumped out and treated.  Monitoring wells are required to check the quality of ground waters in the area.
  • 27. Common wastes which can be disposed are:  Sludge from cyanide bearing wastes,  Sludge from phenol treatment,  Heavy metal containing wastes,  Ash from various treatment categories of wastes,  Discarded containers.
  • 28.  A high temperature thermal oxidation, which converts wastes into gases and combustible substances.  This method is used to dispose combustible liquids and solid hazardous wastes and pesticides and petroleum refineries wastes.  It destroys pathogens & decomposes organic compounds into CO2, H2O, etc.,  This process is adopted for wastes that cannot be recycled or reused.
  • 29.  Developed in late 1800’s.  A specific kind of geological formation must be needed for disposal.  The formation must be deep, providing space & sandwiched between impermeable layers of rock.  This method is very expensive and risky, hence not followed in routine practice.
  • 32.  Biomedical wastes are wastes which are generated during diagnosis, treatment or immunization or in the research and testing biologicals.  Hospital wastes are needles, syringes, surgical gloves, bottles, blood and body fluid, placenta and other body parts, radioactive substances, cytotoxic drugs, chemicals, etc.,
  • 33.  AIDS,  Hepatitis,  Meningitis,  Gastroenteric, respiratory, ocular, genital & skin infections  Anthrax, etc.,
  • 34.  The wastes are disposed by burning it in incinerator at 1200ºC .  Other methods by using autoclave, microwave, hydro wave, etc.,  Wastes burnt below 1200ºC release toxic pollutants like dioxins, furans which are carcinogenic & suppress immune and reproductive systems
  • 35.  Launching mass awareness campaign through electronic and print media to inform clinics and dispensaries to undertake proper management of biomedical wastes.  Training of staffs towards proper segregation of biomedical wastes is also necessary.