Solid Waste Management PDF

. Lesson Outline ❑ WHAT IS WASTE AND ITS CLASSIFICATION ❑ MANAGEMENT AND SEGREGATION OF WASTE ❑ WHY SEGREGATION OF WASTE IS IMPORTANT ❑ METHODS OF SOLID WASTE DISPOSAL AND MANAGEMENT What is Solid Waste? ❑Solid wastes originate from the human activities such as agriculture, industry, domestic a...

. Lesson Outline ❑ WHAT IS WASTE AND ITS CLASSIFICATION ❑ MANAGEMENT AND SEGREGATION OF WASTE ❑ WHY SEGREGATION OF WASTE IS IMPORTANT ❑ METHODS OF SOLID WASTE DISPOSAL AND MANAGEMENT What is Solid Waste? ❑Solid wastes originate from the human activities such as agriculture, industry, domestic activities. Wastes are the material that are not needed and are not usable. ❑Solid waste can pollute air, water and soil, and leave various environmental impacts, and cause health hazard, due to improper handling and transportation.These adverse effects are seen on health and environment. Classification of Solid Waste 1. Garbage : Garbage is Organic refuse resulting from the preparation, storage of food, vegetables , meat etc. It is biodegradable and highly putrescible with moisture content of 70 and heating value of 6 x 106or decomposable, 2. Rubbish : Rubbish is mostly dry material , non putrescible with 25 or lesser moisture content and heating value of 15 x 106. It can be combustible or non combustible Combustible : such as paper, cloth or wood Non combustible : such as glass, metal , ceramics E waste : such as discarded or scrapped electrical or electronic devices. such as CPU , monitor , cellphones etc. It may contain potentially harmful materials such as lead, cadmium, beryllium.etc 1. Pathological waste : Pathological waste consists of recognizable human derived tissues, organs, and body parts as well as animal derived tissues, organs, and body parts used in research Medical Waste : Hospital waste is generated during the diagnosis, treatment, or immunization of human beings or animals. It may include wastes like disposable syringes, swabs, bandages, body fluids, human excreta, Anatomical waste Cultures , Discarded medicines Chemical wastes etc. This waste is highly infectious and can be a serious threat to human health if not managed in a scientific and discriminate manner 1. Agricultural waste : Waste produced as a result of agricultural activities (i.e., manure, inorganic fertilizers , pesticides and herbicides ,field waste , bagasse etc 2. Construction and Demolition waste : Waste obtained from construction and demolition sites and other infrastructures. These includes wood, damaged bricks, electrical wirings, concrete and other debris produced at the construction site. These waste materials from these construction sites may contain hazardous chemicals such as asbestos, lead etc 3. Fly ash /Ashes : These are the residues of the combustion of solid fuels. What Is Solid Waste Management? Solid waste management is defined as the discipline associated with control of generation, storage, collection, transport or transfer, processing and disposal of solid waste. The primary goal of solid waste management is reducing and eliminating adverse impacts of waste materials on human health and the environment to support economic development and superior quality of life. Urban waste includes both domestic and industrial waste. Urban waste amount to around 0.3 to 0.5 kg per person per day. Agricultural waste is around 2kg per person per day Why segregation of waste is important If we do not dispose of the waste in a systematic manner than more than 1400 sq. km of land which the size of the city of Delhi would be required in the country by the year 2047 to dispose of it. How to do it ? After identifying the souce of waste, potential health hazards of the waste is determined. After ascertaining the volume of waste it is collected from the source. Now a days waste is segregated at the source only, It is key to waste minimization and essential for effective waste management. After collection of waste and its segregation ,it is transported to the site for its safe disposal. Segregation of municipal solid waste Municipal waste is being generated in ever increasing volumes in the urban areas. Hence, management of solid waste is very essential, it helps in reducing solid waste pollution and creates pollution free and clean environment. "Bio-medical waste" means any waste, which is generated during the diagnosis,treatment or immunization of human beings or animals or research activities pertainingthereto or in the production or testing of biological or in health camps Red /Brown bins -contaminated waste material that has been in contact with hazardous substances. Used for for chemical and pharmaceutical waste Black- for E waste Blue bin : Recyclable waste Green bins – For organic/ biodegradable waste , Municipal Solid waste Management Methods of solid waste disposal and management are as below: Open dumping Sanitary Landfills. Incineration. Composting. Pyrolysis Recycle and Reuse Biomedical Waste Segregation Methods of waste disposal: Open Dumping : Cheapest method as no planning required.The process practiced extensively in India till few years back.An open dumping is defined as the process in which solid wastes are disposed of in a manner that does not protect the environment, are susceptible to open burning, and are exposed to the elements, vectors, and scavengers. Open dumping has been prohibited by municipality now and no longer practiced in developed countries. Sanitary Landfill : Sanitary landfills are a method of waste disposal where the waste is buried underground in large piles. This method of waste disposal is controlled and monitored very closely. For sanitary landfills, the process starts by digging a large hole in the ground( as deep as 500 feet) that is then lined with thick plastic (normally 2-4 feet thick) and a layer of impervious clay. The bottom of the landfill is also lined with a network of plumbing that functions as a collection system for any liquids (Leachate ) and gas. Leachates is the term used to describe liquids that leach or leak from the landfill, and this system collects the leachates. These components of the sanitary landfill help prevent materials ,liquids and gas from spreading to the surrounding ground and waterways. In modern landfilling system methane can be converted into into power using gas extraction wells that pipe it to plants tha can turn it into electricity Sanitary Landfill Once the landfill is set up, waste can then be added to the landfill. Instead of simply filling the landfill completely with waste, the landfill is organized in layers. The layers alternate between waste and soil. This alternation of materials reduces odors and allows for more rapid decomposition, which is the breakdown of materials. When a landfill is full, it is sealed and covered in a thick layer of clay. Once the landfill has been evaluated and considered safe, it can be converted into a park or open space for human use.It can then be turned into a location for recreation and fun. Concerns related to Sanitary Landfill When sanitary landfills is compared to the previous waste disposal method of open-air piles, the sanitary landfills are definitely better but there are still many issues and concerns associated with it. The largest issue associated with sanitary landfills is the risk of pollution. As waste breaks down, methane gas is created, and if it escapes from the landfill, it could pollute the air. In addition, methane gas can be dangerous if it builds up in the landfill because it is flammable and could be explosive. Along with air pollution, sanitary landfills also pose a threat to water systems. If the lining of the landfill is punctured or the collection system breaks, leachates could travel from the landfill to the surrounding ground and contaminate the groundwater. Another issue with sanitary landfills is their location., they are placed far away from cities and residential areas. Although the distant location of landfills is desirable to people, it causes several problems associated with transporting the waste. The increased transportation results in more air pollution from gas consumption and noise pollution from trucks. There is also concern that, due to the design of sanitary landfills, the rate of decomposition will be slow and potentially incomplete. landfills may not be safe idea because, as the waste decomposes or settles, the land could shift, causing unstable ground. Incineration It is the process of burning municipal solid waste and hazardous waste specifically hospital waste in a properly designed furnace under suitable temperature and operating conditions. It reduces the hazardous / municipal solid waste by about 90% and 75% by weight. The technique of incineration revolves around controlled burning of the waste. It helps in reducing the volume of waste and saves a great amount of space in the landfills. Burning the municipal solid / hazardous waste releases some harmful gases that might affect the quality of air. At the end of the process , tons of toxic ash (left in furnace) and fly ash ( ash which floats out in air) is left behind. It contains high concentration of heavy metals and dioxins. It is finally buried in landfill with precaution. Incineration The process can be made more effective with the use of filters and scrubbers, Scrubbers use liquid for lessening the acidic content of the gases, while the filters prevent the burning ash from entering the atmosphere. Combustion reduces the toxicity of the waste materials to greater extent. If properly equipped, an incinerator is also capable of converting water into steam, which, in turn, can be used to generate power. Demerits: Burning trash releases dioxin, lead, and mercury (in many areas, incinerators are the largest sources of these pollutants Cost of incinerators : are often two to three times higher than comparable recycling or composting costs. Composting Bacterial decomposition of organic components of the municipal waste result in the formation of humus or compost and the process is known as composting. It helps in disposal of solid waste, disposal of night soil, and production of valuable manure for crops, Composting offers a method of processing and recycling both garbage and sewage sludge in one operation. It involves two stages as written below : 1.Sorting and shredding : The decomposable materials in refuse are sorted ,shredded or pulverized resulting in a uniform mass of material. It is accomplished by rotary shredders. 2.Digesting and processing : Depending on moisture conditions, it may take five to eight weeks for complete digestion of the waste. Because of the metabolic action of aerobic bacteria, temperatures in an active compost pile reach about 65 °C (150 °F), killing pathogenic organisms that may be in the waste material. Digested compost must be processed before it can be used as a mulch or soil conditioner. Processing includes drying, screening, and granulating or pelletizing. Recycling and Resource Recovery Recycling : It means reusing some components of the waste that may have some economic value. Recycling conserves resources, reduce the energy used during manufacture and also reduce pollution. Source recovery (pyrolysis): It is a process of destructive distillation in which the solid wastes are heated in pyrolysis reactor at 650-1000 degree centigrade in oxygen depleted environment. By this process, the chemical constituents and chemical energy of some organic wastes are recovered. The organic constituents split up into gaseous liquid and gaseous fractions like carbon dioxide, carbon monoxide, tar, methane, charred carbon etc. The total amount of waste material composted and recycled managed to keep about 178 million metric tons of carbon- dioxide away from the atmosphere, which is similar to taking more than 33 million vehicles off the roads for a period of one year. On the whole, recycling helps in conserving natural resources, reduces the amount of emissions. Waste Management hierarchy The waste management hierarchy can be divided into four parts, also known as the Four R's: Refuse, Reduce, Reuse, and Recycle. Refuse/source reduction : Cut down the waste simply by refusing to buy single- use plastics. Reduce: Part of throwing away less is buying less, and being more mindful as a consumer. Reuse: Before tossing out your trash, consider whether it can be repurposed as something else. For eg Turn single-use plastics into ecobricks Recycle : After refusing, reducing, and reusing, recycling is the last resort in the waste management hierarchy.