Solid Waste Management Unit 2 PDF

1 UNIT- 2 Solid Waste Management and treatment Technology Solid Waste Management and treatment Technology: Introduction to Unit- E-Waste, Biomedical waste and Solid waste. Treatment: Collection, II segregation, transportation and its disposal techniques 1.1 INT...

1 UNIT- 2 Solid Waste Management and treatment Technology Solid Waste Management and treatment Technology: Introduction to Unit- E-Waste, Biomedical waste and Solid waste. Treatment: Collection, II segregation, transportation and its disposal techniques 1.1 INTRODUCTION & OBJECTIVES Municipal solid waste is the waste which consist of everyday items that we use and throw away. It consist of food, vegetables, paper, plastic, glass waste etc. It includes residential and commercial waste. Due to industrialization and urbanization, the amount of solid waste generation is increasing day by day. If solid waste is not properly managed, it causes problems with air, water and soil. As a part of disposal solid waste is dumped into landfill. Apart from the fact that human health is at great risk, life becomes unbearable to dwellers in such environments. Some of the solid waste is incinerated to reduce the volume of waste, which results in air pollution due to increase in greenhouse gases. The outcome of uncontrolled disposal of solid wastes not only cause environmental degradation such as in flooding, drainage obstruction but also when exposed to human causes widespread of infectious diseases, cholera, diarrhea, typhoid fever and due to breeding of mosquitoes, malaria and plagues. Hence, it is important to study solid waste management. 1.2 Types of waste 1. Solid waste 2. Liquid waste 3. Organic waste 4. Recyclable waste 5. Hazardous waste 6. Radioactive Waste 1.3 Solid waste Solid waste is defined as Non-liquid, non-soluble materials ranging from municipal garbage to industrial wastes that contain complex and sometimes hazardous substances. Solid waste includes trash or garbage consisting everyday items. If it is not managed properly, can create remarkable health issues and miserable living conditions by giving a hospitable environment for insects, bacteria and viruses’ growth and an unattractive visual appearance of many collection sites and odors associated with solid waste. Its poor management causes air pollution, water and soil contamination.  2 Uncontrolled hazardous wastes from industries mixing up with municipal wastes create potential risks to human health like-  Cancer  Congenital malformations, mainly urinary tract defects  Pre-term birth or low birth weight  Neurological diseases 1.4 Solid waste Management Solid Waste Management is todays emerging issue for the safe environment and healthy life. The primary goal of solid waste management is reducing and eliminating adverse impact of waste on human health and environment to support economic development and superior quality of life. Waste generation has increased day by day due to increasing population, industrialization and urbanization. With rapid population growth and urbanization municipal waste generation is expected to rise to 2.2 billion tons by 2025. Increasing use of technologies and recent gadgets will generate large amount of electronic waste which contributes to about 27% of total waste generated. Hence, it is necessary to minimize waste generation and recycling of recyclable waste Solid waste management is the comprehensive program of waste prevention, recycling, composting and disposal. Components of solid waste management: 1. Waste Generation Waste is generated when materials become useless to the owner and they wish to discard them. 2. Storage It is a mid-step between generation and collection of waste. It may not be needed if the people are dumping waste directly into pits. In cases, where there are heaps of waste, the storage facilities must be provided like big containers, bins, drums, shallow pits or walled areas. The quantity of these facilities depends upon the number of users, type of waste and frequency of emptying. Household waste storage can be done in boxes, containers, bins, plastic bags etc. These storage systems must be isolated, should not absorb moisture when in contact with water unlike cardboard boxes, and have good strength and easy to empty. 3. Collection In this stage, waste is collected form households, shops or other premises, sweeping places etc. and then taken for disposal. This is the most important aspect of solid waste management as it needs a  3 good amount of labor force and budget. It includes loading, unloading and transfer till reaching the destined dumping site. Waste collection can be done from different locations using methods like community containers, block collection system, yard collection, from apartment buildings etc. 4. Segregation Separation of waste at household level has been given some thought but such system is exhausting at economic and social level, especially in developing countries. To overcome this burden, private and informal sectors are taken into account. For instance, wastes from markets, restaurants and hotels may get collected separately from animal feed, street sweepings, composting material. In the same manner, the household garbage can be collected separately from hospital or medical or healthcare waste. Industrial waste, construction waste and demolition waste contain a large amount of sand so these may also be collected in separately. Another way of waste segregation is distinct collection of paper, plastic, metal and glass which is becoming more and more popular. 5. Transportation To empty the collection containers and bins, transportation is needed for disposal at the site. The methods of transportation are mentioned below: Human-aided- This transport method includes tri-cycles, handcarts or barrows. But these methods are appropriate for short distances, less load and where larger vehicles cannot enter. Power-driven- These include motorcycle trailers, two-wheeled tractors, three-wheeled auto- rickshaw, micro-trucks etc. All these means are fast and efficient. They can carry load to a greater distance without much hard work. 6. Disposal Mainly, there are two types of disposal- a. Open dumping b. Sanitary landfilling c. Incineration d. Pyrolysis e. Composting a. Open dumping- The waste is unloaded at any convenient open space. The people residing nearby may light fire to reduce the amount of waste or to get rid of the flies. This adds to the air pollution which contains toxic gases. Scavenging at these kinds of disposal sites is very dangerous,  4 especially when medical waste like needles and blades are mixed with it. Open dumps pose health, safety and environmental threats. b. Sanitary landfilling- Waste is placed in a large pit and at the end of each day, a layer of soil is spread over the waste and then compacted. Same day filling back is necessary to prevent animals from eating or digging and flies from breeding. This site should be at a good distance from the nearby population. The working area is confined to the smallest area, with extensive site preparation. c. Incineration- This method involves burning of waste till it is converted to ash. This method can reduce 20- 30% of waste. In solid-waste management, Burning is a very effective method of reducing the volume and weight of solid waste, though it is a source of greenhouse gas emissions. In modern incinerators the waste is burned inside a properly designed furnace under very carefully controlled conditions. Incinerators d. Pyrolysis: Pyrolysis represents a process of thermal degradation of the waste in the total absence of air that produces recyclable products, including char, oil/wax and combustible gases or Pyrolysis is the heating of an organic material, such as biomass, in the absence of oxygen. Because no oxygen is present the material does not combust but the chemical compounds (i.e. cellulose, hemicellulose and lignin) that make up that material thermally decompose into combustible gases and charcoal. This process is carried out between 500 to 10000C.  5 e. 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 percent. Organic waste in landfills generates, methane, a potent greenhouse gas. By composting wasted food and other organics, methane emissions are significantly reduced. Compost reduces and in some cases eliminates the need for chemical fertilizers. Compost promotes higher yields of agricultural crops. 1.5 E-waste (Electronic Waste)  6 E-Waste comprises of a broad and growing range of electronic devices, ranging from large household devices such as refrigerators, air conditioners, cell phones, personal stereos, and consumer electronics to computers which have been discarded by their users. Globally only 15 – 20 percent of e-waste is recycled while the rest is dumped into developing countries. Categories of e-waste: 1. Large household appliances (refrigerators/freezers, washing machines, dishwashers) 2. Small household appliances (toasters, coffee makers, irons, hairdryers) 3. Information technology (IT) and telecommunications equipment (personal computers, telephones, mobile phones, laptops, printers, scanners, photocopiers) 4. Consumer equipment (televisions, stereo equipment, electric toothbrushes) Electronic waste generation worldwide: Globally, China is the largest producer of electronic waste worldwide, generating more than 10 million metric tons in 2019. This was approximately three million metric tons more than was produced in the United States. India generates about 3 million tonnes (MT) of e-waste annually and ranks third among e-waste producing countries, after China and the United States. India is the third largest electronic waste generator in the world after China and the US and these three countries together contributed to almost 40% of total e-waste generated worldwide in 2019 Statistica Report 2020 Rank Country Generation (million tons per annum) 1 China 10.1 2 USA 6.9 3 India 3.2 4 Japan 2.5 5 Brazil 2.1  7 Toxic metals in e-waste: Electronic devices form a complex mixture of materials and components often containing several hundreds of different substances, many of which are toxic and create serious pollution upon disposal. These include heavy metals such as mercury (Hg), lead (Pb), cadmium (Cd), chromium (Cr) etc E-waste sources, constituents and affected body parts No. Sources Constituents Hazards and health effects 1. Solder in printed circuit Lead Damage to kidney, central nervous boards, glass panels and system, circulatory systems and adverse gaskets in computer monitors effect on brain development of children 2. Chip resistors and semi- Cadmium Toxic irreversible effects on human conductors health, damage to kidney, liver and nervous system 3. Relays, Switches and printed Mercury Chronic damage to the brain, respiratory circuit boards and skin disorders 4. Galvanized steel plates and Chromium Causes bronchitis and other respiratory decorator or hardener for disorders steel housing 5. Cabling and computer Plastics and PVC Burning produces dioxin that causes housing reproductive and developmental problems 6. Electronic scrap and circuit Brominated flame Disorder of Endocrine system boards retardants 7. Front panels of CRT’s Barium, Causes muscular problems, damage to phosphorus and heart, liver and spleen heavy metals 8. Copper wires and PCB Copper Stomach cramps, nausea, liver damage or Wilsons’s disease 9. Lithium ion batteries Lithium Lithium can pass into breast milk and may harm a nursing baby, inhalation causes lung edema 10. Nickel-cadmium Nickel Dermatitis, Asthma rechargeable batteries 11. Motherboard Beryllium Lung cancer, inhalation causes chronic beryllium disease or Beryllicosis 1.6 Biomedical waste Biomedical waste is defined as any type of waste created during a diagnostic process, the treatment of a condition or disease, or immunizations of humans or animals. It also includes any research  8 activities or processes that involve biological testing. When bio-medical wastes are mishandled, radioactive elements can enter landfills and other areas. Exposure to radioactive elements can lead to serious diseases. Therefore, the soiled cotton swab is considered potentially hazardous, and special waste management procedures are necessary to dispose the same. Biomedical waste should be segregated in colored coded paddle operated covered bins. Colour Type of Containers Coding Plastic bag, Pathological waste, Medical chemical waste, Pharmaceutical waste Yellow (discarded/expired medicines and drugs) Red Disinfected Container or Contaminated waste White Plastic bag/puncture proof container, Sharps waste translucent Blue Medical glassware waste Types of Biomedical Waste Disposal:  Autoclaving: The process of autoclaving involves steam sterilization.  Incineration: The major benefits of incineration are that it is quick, easy, and simple.  Chemicals: When it comes to liquid waste, a common biomedical waste disposal method can be chemical disinfection.