‘Waste’ is a very general word, used to include anything that is no longer needed for use and is thrown away uncared. It has created and added a new problem to the environmental pollution. Pollution also creates serious problems for human health. There is remarkable growth in energy generation, fertilizers, pesticides, chemicals, production of coal etc. All these and much more is expected to increase in the years to come. For this, we need to understand different sources of waste. GENERATION OF WASTE: ITS SOURCES
What is Waste? Any thing that is no longer needed for use and is thrown away uncared, is Waste. Wastes – (a) Occupy some space (wherever they are thrown), (b) produce smell and (c) have weight. Therefore, wastes are matter only. Therefore, the material, which is discarded after use, is referred to as waste. Usually the term waste is used for solid residues. Actually, waste is not only solid but also liquid and gaseous. Now it is clear that unwanted wastes contaminate air, water and soil ecosystems.
Although all living beings generate waste products, in our country the population is more than 100 crore, hence we can imagine the amount of waste that is added to the surroundings. All human activities generate waste, therefore tones of waste is produced every year by various human activities. Most of the waste generated from household activities, industries, offices, hospitals and agriculture. Nevertheless, more waste is generated in urban areas than in villages. |DO YOU KNOW …..? | |Pollution refers to any undesirable change in our environment i. e. ir, water and soil that may adversely affect humans or other | |species. Pollutants cause the pollution. In simple words, pollutants are the wastes, which are residues of things we make use and throw| |away. | Sources of Waste Generation The sources of waste generation are many and vary from country to country and city to city. It is generated from a number of sources. The major sources are – 1. Domestic sources of waste 2. Industrial sources of waste 3. Agricultural waste 4. Municipal waste 5. Commercial waste 6. Medical waste 7. Electronic waste 8. Hazardous waste 1. Domestic waste :
Domestic sources of waste are commonly known as refuse. It can be classified into following categories – a) Garbage: These are the things that are used for a period and then thrown as waste. It contains fruits and vegetables peels, kitchen garbage, household rubbish, paper, plastics, glasses, broken bottles, etc. It has to be deposited properly as it breeds flies and insects. They spread various diseases. b) Rubbish: It contains paper, plastics, rubber, wood etc. c) Excreta: It contains human and animal excreta. It should be properly disposed, otherwise causes environmental pollution. ) Sullage: It is the wastewater disposed off from bathroom, latrine and kitchen. e) Ashes: When a solid fuel like coal, wood etc. is burnt, the residue left over is called ash. All these wastes are harmful for living beings, affect plant’s growth and cause diseases. These are disposed off by land filling, incineration and composting. Following table shows various human activities from which wastes are generated and their types of waste generated. | Various human activities | Types of waste generation | | | |Domestic wastes |Garbage and peeling of fruits and vegetables, other eatable things, paper, dust, | | |plastic etc. | | | | |Industrial wastes |Waste generated from power plant, construction sites, paper industries, textile | | |mills, cement industries etc. | | | | |Animal wastes, Plant remains and wastes from field etc. | |Agricultural wastes | | | |Garbage; dust, waste water and garbage from kitchen needles, latrine, street, | | |shops etc. |Municipal wastes | | | |Wastes from clinics, hospitals like needles, syringes and bandages. | | | | |Medical-aid-care | | 2. Industrial Wastes : Industries produce large amount of waste.
The raw materials used in industries generally comes packed in containers and boxes that are discarded in large quantities. These materials do not get decomposed easily and as such remain in environment ultimately polluting it. Now we study about the wastes released from different industries. a) Iron and Steel Industry: Huge quantities of solid wastes are produced in the manufacturing of steel. This industry uses coal, lime, manganese, iron ore and water as raw materials. These wastes consist of dust, slag and sludge. Many acids are released like hydrochloric acid, sulphuric acid, nitric acid etc.
These kinds of waste products are difficult to dispose. b) Tanneries: The place where leather is made from animal skin is known as Tanneries. The wastes from tanneries cause maximum pollution amongst all the industrial wastes. c) Textile Industry: In textile mills, various fibres are used like cotton, woolen, silk, synthetic etc. For dying the fibre, a lot of water is used. When this water is released as waste, it is mixed with many chemicals. These liquid wastes from this industry pollute the environment. d) Paper and Pulp Industry: The solid wastes produced from these industries are screen dust, chips, mud from bleaching units etc. iquid wastes produced from pulp industry, which are extremely hazardous to the marine creatures. e) Thermal Plants: Thermal power plants require some fuel like coal. It is used to make steam that operates the generator. Tons of ash is left behind known as fly ash. When coal is burnt, other gases are also released along with the smoke as gaseous waste. These wastes are very harmful to the environment. f) Nuclear Power Plants: The major raw materials used in the generation of nuclear power are-uranium and plutonium. Its waste remains radioactive for thousands of years. Hence, it can bring harm even to the future generations. ) Other Wastes: Besides these some industry, rubber-manufacturing industries, detergent industry, etc. produce various kinds of wastes in the environment. Oil refineries and petro-chemical plants release wastes containing mainly hydrocarbons, organic acids and inorganic sulphur compounds. |DO YOU KNOW … | |Slaughter houses are the places which produce wastes like hides, skins, blood, bones, hair etc. These cause water pollution when | |released in water bodies. | 3. Agricultural Waste
Agriculture is the process of cultivating the soil, harvesting crops and raising livestock. Modern agricultural techniques have increased. Agriculture includes ploughing, sowing, harvesting, threshing, winnowing, poultry farming, dairy farming, etc. a) Fertilizers: Fertilizers are used to improve the fertility of the soil. These are rich in nutrients like nitrogen, phosphorous and potassium as such enhance the growth of plants. Fertilizers can be divided into two groups- Chemical fertilizers are made of chemicals that are produced in factories. Plants use only 60% of chemical fertilizers that are added to the soil.
Organic fertilizers are made from organic wastes such as animal excreta and plant wastes. These include cow dung and compost, which are bio-degradable. b) Insecticides: Insecticides are used to kill insects that destroy the crop. DDT and aldrin are common insecticide. c) Pesticides: Pesticides are used to kill pests that harm crop. They cause irritation in eyes, fatigue, dizziness etc. d) Herbicides: These are the chemicals, used to kill fungi. E. g. dithiocarbomates. e) Rodenticides: These are the chemicals used to kill rats, mice etc. E. g. non-bromide and strychnine. 4.
Municipal Waste: This include garbage, rubbish etc. from offices, markets, hotels, households etc. and the street refuse like sweeping dirt, litter etc. Garbage is generally biodegradable food, wastes and rubbish non-bio-degradable solid waste. Apart from these ashes, dead animals, pipes, wires, insulations, abandoned vehicles constitute the municipal wastes. 5. Commercial Waste: Waste products generated from shops, stores, restaurants etc. are called commercial waste. For example, construction debris, chemicals from printing press, plastic cans, fibres, glasses, cement factories etc. . Medical Waste: The waste things that are generated from laboratories, hospitals etc. are medical waste. These are infectious. Every day a number of patients visit hospitals and clinics. Their treatment generates a lot of infectious waste. It includes bandages, cotton, syringes, expired medicines, plastic bottles, bags etc. All should be disposed off properly as they may be toxic. 7. Electronic Waste: Electronic waste mostly consists of electronic items like abandoned computer parts (monitor, keyboard, CD’s chips, hard disk, floppy, etc. ), mobile phones, T.
V, electronic iron etc. 9. Hazardous Waste: These are the substances that cause harm to human beings, plants and the environment. It includes waste water treatment, sludges from electroplating and sludges from oil refineries, dewatered air pollution, blast furnace sludges, radioactive waste and medical waste. Hazardous waste can be divided into five main categories- a) Radioactive wastes b) Bio-medial wastes c) Non-radioactive industrial liquid wastes. The organization chart given below shows the three different types of hazardous wastes. [pic] TYPES OF WASTE Introduction
Any material that is discarded after use is referred to as waste. We have learnt in the previous chapter that there exist a number of sources that generate waste. With increase in the industrialization and urbanization, the quality of waste generated is estimated to be up to one ton per family in a year, which is hazardous to living creatures and environment. In order to understand the impacts of waste accumulation in environment, one need to first understand the impacts of waste accumulation in environment, one need to first understand the types of wastes. Types of Waste
A waste is a movable object that has no direct use and it is discarded permanently. In other words, ‘Waste’ is something the owner no longer wants at a given place and at a given time and has no current or perceived market value. There are potential risks to the health and environment if these wastes are not handled properly. For this purpose, it is necessary to classify them. Generally, waste is of three types- 1. Bio- degradable Waste 2. Non- biodegradable Waste 3. Toxic Waste The following Organization Chart given below shows the three different types of waste- bio-degradable, non-biodegradable and toxic wastes pic] a) Bio- degradable Waste: Bio- degradable wastes are the waste that decays and mix with the soil. They can be broken into simpler forms by the action of micro- organisms. They are very easy to be disposed off and are disposed off by composting, landfills, etc. They are animal wastes, plant debris, mineral-based products, domestic garbage etc. b) Non- biodegradable Waste: Non-biodegradable wastes are the wastes that do not break into simpler forms by the action of micro- organisms. They also do not decay and mix with the soil. It is very difficult to dispose them off..
The best way of dispose them off is to recycle them. Some examples of non- biodegradable waste are glass, plastic, metals, tin cans, DDT, insecticides, pesticides, electronic waste, mercuric salts, radioactive waste etc. c) Toxic Waste: Toxic wastes include non- biodegradable wastes. However, they are different as they are more dangerous are more difficult to dispose them off. They are the poisonous wastes which do not easily settle down and broken by biological means. It includes municipal waste, agricultural waste, industrial waste and bio-medical waste.
It is also important to classify the waste depending on their physical states. Based on physical appearance, waste is of three types- 1. Solid waste 2. Liquid waste 3. Gasous waste The following organization chart given below shows the three types of waste based on physical appearance.