SOLID WASTE MANAGEMENT All solid and semi-solidwastes arising from human and animal

1. SOLID WASTE MANAGEMENT All solid and semi-solidwastes arising from human and animal activities, except human-excreta and sullage (liquid wastes from bathrooms, kitchens, etc.), are discarded as useless or unwanted are included in the term ‘Solid-Wastes’ or ‘Refuse’. It includes garbage, rubbish, ashes and residues, demolition and construction wastes, dead animals, radioactive wastes, etc. The quantity of solid-wastes produced depends upon the living standards of the population. It will be more for an industrialized modern society. It also depends on seasons.

2. A few important terms used in solid-wastes are : Rubbish. It includes combustible and non-combustible solid wastes, excluding food wastes or putrescible materials. Combustible rubbish includes paper, card-board, textiles, plastic, rubber, wood, garden-trimmings, etc. Non-combustible rubbish consists of glass, crockery, tin-cans, aluminium cans, metals, construction wastes, etc. Garbage. It includes putrescible organic waste like the animal, fruit or vegetable residues resulting from the handling, preparation, cooking and eating of foods.

3. Types and Sources of Solid-wastes There are three general categories of solid-wastes : (i) Municipal wastes, (ii) Industrial wastes, and (iii) Hazardous wastes.

4. Municipal wastes Municipal wastes are those wastes which arise from household activities, restaurants, public places, institutions, markets, street-sweepings, etc. and typically include garbage, rubbish, ashes (due to burning of coal, wood etc.), demolition and construction wastes, street-sweepings, dead animals, etc. and also treatment plant waste. The general sources of municipal solid-waste are residential, commercial (markets, hotels, garages, institutions, etc.) and open areas (streets, parks, beaches, highways, play grounds), etc.

5. Industrial wastes Industrial wastes are those wastes which arise from industrial activities, and typically include rubbish, ashes, construction and demolition wastes, special wastes and toxic wastes.

6. Hazardous Wastes Are those wastes that pose a substantial danger immediately or over a period of time to human, plant or animal life. A waste is said to be hazardous if it exhibits any of the following characteristics, viz., ignitability, corrosivity, reactivity or toxicity. Typical hazardous wastes are radioactive substances, chemicals, biological wastes, flammable wastes, and explosives. The sources of hazardous wastes are industries, nuclear plants, hospitals, research institutes, laboratories, etc.

7. Reasons of excess generation of Solid Wastes The main causes for the rapid growth in the quantity of solid wastes are : (i) Over-population. The ever increasing population is increasing all types of pollution. Same is true for solid waste pollution too. (ii) Urbanization. Solid waste is primarily an urban problem, though it is not exclusively urban. Solid waste pollution increases with the increase in urbanization. In developed countries, for instance in USA urban areas produce about 7.0 lac tons of solid wastes each day—an amount sufficient to cover more than 1.6 sq. km. of land every day to a depth of 3.0 m.

8. (iii) Affluence. With production or per capita consumption, there is a tendency to declare items as obsolete, resulting in their discard. This leads to solid waste pollution. (iv) Technology. Rapidly growing technologies for most economic goods are leading to returnable packaging to nonreturnable packaging. For example, returnable glass bottles/ containers being replaced by non-returnable cans, plastic containers, etc.

9. Effects of Solid Wastes Pollution The improper handling and transfer of the solid wastes results in various health and environmental hazards, such as : • Diseases like bacillary dysentery, diarrhoea and amoebic dysentery may result in humans from food and water contamination through flies, which breed on the refuse dump and solid waste. • Rats depending upon these solid wastes may also cause plague, salmonellosis, trichinosis, endemic typhus like diseases through direct bite. • The crops and water supply may also get contaminated and may result in large scale epidemic of cholera, jaundice, gastrointestinal diseases, hepatits etc.

10. • Solid wastes may also choke the drains and gully pits resulting in water logging, which in turn results in the breeding of mosquitoes and thus danger of malaria and dengue. • There is also aesthetic danger to the surrounding environment, as the stray animals and scavengers invade the garbage dumps of roadsides. • Obnoxious ordors also pollute the air due to decomposition of organic solid wastes. • Noxious fumes may pollute air due to the burning of waste products especially plastic containers. • Percolation of decomposed garbage dumps into soil may result into pollution of underground water and land.

11. Methods of Solid-wastes Disposal The various methods of solid-wastes disposal are : • Land filling, • Incineration, • Pulverization, • Composting, • Pyrolysis, and • Disposal into sea.

12. 1. Disposal of Solid-Wastes by Land Filling In this method, solid-wastes are carried and dumped into the low lying areas. The refuse is filled up or dumped in layers of 1.5 m or so and each layer is covered by good earth of atleast 20 cm thickness, so that refuse is not directly exposed. Each layer is left out for atleast seven days and compaction by trucks is carried out for its settlement, before starting filling the next layer. Insecticides like DDT should be sprayed on top to prevent breeding of mosquitoes and flies.

13. With the passage of time, the filled up solid-wastes will get stabilized by the decomposition of the organic matter and subsequent conversion into stable compounds. Hydrolysis of complex organic matter takes place under anaerobic conditions and as a result gases like CH4, CO2, H2S, etc. are evolved and also simpler water soluble organic acids are formed which diffuse through the soil. For better biological degradation the moisture content should be less than 60%. The refuse gets stabilized, generally, within a period of 2 to 12 months, and settles down by 20 to 40% of its original height. Unequal settlement and odour may be there for the first few years. But after that the land can be used for developing parks or other recreational use.

14. Advantages : • Simple and economical. • No costly plant and equipment is required. • Skilled labour is not required. • Separation of different kinds of solid-wastes is not required. • No residue or by-product ; hence no further disposal. • Low-lying areas can be reclaimed and put to better use.

15. Disadvantages : • Large land area requirement. • Continuous evolution of foul smell near the site of disposal. • Use of insecticides is required. • Covering good earth required for top layer may sometimes be difficult to obtain. • The biggest disadvantage is formation of ‘leachate’. It is a coloured liquid formed due to seepage of rainy water into the land fill. This water may dissolve the harmful and carcinogenic compounds present in the refuse. When such a polluted water contaminates the ground water, it may lead to diseases like cholera, typhoid, polio, etc.

16. 2.Incineration Incineration means burning of the solid-wastes in properly constructed hearth of furnaces. This method is generally used when suitable dumping land areas are not available and disposal in sea is not possible. When solid-waste is collected together, it is better to separate the non-combustible and inert material like earth, broken glass, chinaware, metals, etc., so as to reduce the load on the hearth. The combustible garbage, rubbish and dead animals are only burnt. The minimum temperature in the combustion chamber should be greater than 670°C to incinerate all the organic matter and oxidize the foul smelling gases. If steam is to be generated then a temperature of about 1000°C is to be produced in the combustion chamber.

17. Each batch of solid-wastes entering the furnace should be well-mixed and the proportion of the fuel in the charge be adjusted to provide complete combustion and proper temperature. When the moisture contents of the solid-wastes is high, auxiliary fuels like wood, coal or oil may be used. The final products will be ashes and clinkers. The ashes are dispersed by dumping in low lying areas, while the clinkers can be used as aggregate for low grade concrete or as road material.

18. Advantages : • The method is sanitary, as all the pathogens and insects are destroyed. • No odour and dust nuisance. • Same revenue can be generated by raising steam power and selling of the clinkers. Disadvantages : • Relatively high initial cost. • Nuisance of smoke, odour and ash during the improper functioning of incinerators.

19. 3. Pulverization In this method, the solid-waste is pulverized in grinding machines so as to reduce its volume and change its physical character. By doing so it becomes practically odourless and unattractive to insects. Although it contains fertilizing elements, but it cannot be suitably used as a manure. It has to be further disposed of by land filling. The method is quite costly, and hence not commonly used, particularly in India.

20. 4. Composting In this method the putrescible organic material in solid-wastes is digested anaerobically and converted into humus and stable mineral compounds. Its volume is also considerably reduced and is made free of most of the pathogenic organisms so that is can be easily and safely handled. It is a hygienic method which converts the solid-wastes into manure through anaerobic bacterial action. This method is best suited to Indian conditions, especially for small and medium size towns ; since it solves three problems simultaneously—disposal of solid-wastes, disposal of night soil (where there is no water carriage system of sanitation), and production of valuable manure for crops.

21. There are three methods of composting, as explained below : Composting by Trenching. In this method, trenches 4 to 10 m long, 2 to 3 m wide and 0.7 to 1.0 m deep are excavated at a clear spacing of 2 m. Solid-waste is disposed of into these trenches in layers of 15 cm and by sandwiching 5 cm layers of night soil or animal dung in semi-liquid form, till the heaps so formed rise about 30 cm above the original ground level. A layer of 5 to 7.5 cm of good earth is then spread on top to prevent the flies from getting access into the heaps and for the wind blowing them off. Within 2-3 days, intensive biological action starts and the organic matter begins to be destroyed. Considerable heat is produced in the process to raise the temperature of the decomposing mass to about 75°C.

22. This generated heat prevents any breeding of flies. After about 4-5 months, the decomposing mass gets fully stabilized and changes into brown odourless innocuous powdery humus having high fertilizing value. It is then removed from trenches, sieved on 1.25 cm sieve to remove coarse inert materials like stones, brick bats, broken glass, etc. The sieved material is then sold out as manure. The same trenches can be used again for receiving further batches of solid-wastes.

23. Open Window Composting. In this method, the coarse inert matter is first removed from solid-wastes. Then it is dumped on the ground in the form of 5 to 10 m long, 1 to 2 m wide and 0.5 to 1.0 m high piles at about 60% moisture content. The pile is then covered with night soil/ animal dung. Due to biological activity through aerobic bacteria, heat starts developing upto about 75°C in the piles. After few days the pile is turned up for cooling and aeration to avoid anaerobic reactions. The pile temperature again rises and the process of turning, cooling and aeration is repeated. The complete process may take about 4 to 6 weeks, after which the compost is ready for use as manure.

24. Mechanical Composting Mechanical composting stabilizes the solid-wastes only within 3 to 6 days. The various unit processes or operations involved in a large scale mechanical composting plant are—reception of solid-wastes, segregation, shredding or pulverization, stabilization, and preparation of the stabilized mass for the market. Stabilization is carried out, under controlled conditions of temperature and moisture content, in mechanical digesters. The mechanical digesters are of various types, such as pits or cells, windows or stacks, and vertical or horizontal cylinder or silo type closed digestors.

25. Closed digestors are most hygienic and occupy less space. In these digesters, the refuse is digested and converted into humus and stable mineral compounds. The stabilized brown humus is collected, sieved and sold in market. Sometimes, the stabilized mass is enriched by adding chemical nutrients like phosphorus, nitrogen, etc.

26. 5. Pyrolysis In pyrolysis, the chemical constituents and chemical energy of some organic wastes is recovered by destructive distillation of the solid waste. In pyrolysis, the combustible constituents of the solid-waste are heated in a specially designed retort like chamber, known as pyrolysis reactor at 650 to 1000°C in an oxygen-free (or low-oxygen) environment. Pyrolysis is an endothermic process and thus differs from the conventional incineration. Its merits and demerits are same as that of incineration process discussed earlier.

27. 6. Disposal into Sea This method of solid-wastes disposal can be used in coastal areas having deep sea water ( > 30 m) at a reasonable distance ( < 16 to 20 km), and with strong forward currents. This is quite a simple and cheap method, but it has following disadvantages : • The bulky and lighter components of solid-wastes float, spread, and tend to return to the shores during high tides. • During monsoons or stormy weather, solid-waste has to be either stored or disposed of by some other methods. • Some portion of the solid-wastes may return and spoil the beaches, despite all the necessary precautions.

28. Solid Waste Management Solid waste management may be defined as the application of techniques that will ensure the orderly execution of the functions of collection, processing and disposal of solid waste. These functions are called the ‘three basic functional elements of solid waste management’. Collection is the first fundamental function of solid waste management. It refers to the gathering of solid wastes from places such as residences, commercial, institutional and industrial establishments, and other public places. Generally, there are two methods of collection— hauled-container system and stationary-container system. In the hauled container system, the container is hauled from the collection point to the final point of disposal, processing facility, or transfer station. In the stationary-container system, the container is emptied into collection vehicles at the point of collection.

29. Processing is the second fundamental function of solid waste management. It refers to the activity applied to solid waste to prepare it for subsequent operation. Processing improves the efficiency of solid waste disposal and prepares solid waste for subsequent recycling and recovery of materials. Disposal is the third fundamental function of solid waste management. It refers to the placing of solid waste in its ultimate resting place. The various methods of solid waste disposal have already been discussed earlier.

30. Recycling of Solid Waste and Its Management The recovery of solid waste components for possible use as raw materials is called recycling or salvaging. It involves separating materials (such as scrap metal, glass, paper, plastic, etc.) from refuse and reprocessing them for reuse. Processing to segregate solid waste components may be done at the point of generation (on-site processing) or at a central processing facility. In on-site processing, wastes are segregated into different types at the point of generation. For example, paper is put in one container, metal scrap in another, and so on. The onsite processing, thus, needs the cooperation of the waste producer (e.g., houses, industries, commercial establishments, etc.) If on-site processing is not done, segregation into components may be done at a central facility. Unit operations in a central facility involved—screening, air classifying, and magnetic separations. Size reduction using shredders, although not a segregation process, is also sometimes used to produce a more uniformly sized product.

31. The various recycling techniques that can be utilized are as under : (i) Crushing of materials such as discarded furniture, appliances, etc. (ii) Selection for magnetic, non-magnetic and specific gravity based materials. (iii) Thermal decomposition of waste organics in the form of gas and oil. (iv) Food sources from organic wastes for livestock. (v) Melting plastic domestic toys and moulding them into new ones. (vi) Melting blast furnace slag for making artificial jewellery etc. (vii) Use of incineration heat. (viii) Methane fermentation and residual sludge. (ix) Converting waste into solid fuel (wood chips, raw dust etc.) (x) Alcohol fermentation. (xi) Composting garbage and using it as manure.

32. Examples of Recycling and Waste Utilization • Construction Materials from Wastes • Utilizing Agricultural Wastes • Medicines from Agricultural Wastes • Utilizing Slaughter-houses Wastes • Recovery of Heavy Metal Ions • Liquid Fuels from Agricultural Wastes • Energy from Industrial and Urban Wastes. • 8. Conversion of Agricultural Wastes into Cheap and Efficient Fuel • 9. Rubber from Old Tyres • 10. Proteins from Cellulose Waste. • 11. Utilizing Aquatic Weeds • 12. Oil from Plastic Waste • 13. Plastic for Heat and Electricity Generation • 14. Silk Industry Waste as Poultry Feed • 15. Utilizing Fly Ash as Bricks

33. DISASTER MANAGEMENT The term ‘Disaster’ is derived from the French word ‘Desastre’ meaning a bad or an evil star. A disaster is that sudden calamity which brings misfortune and miseries to humanity. Disasters have serious impact on human life, economy and environment. They disrupt the normal pattern of life because a disaster is often sever, sudden, unexpected and widespread. Natural disasters are always severe and sudden. Some disasters are geological in nature like the earthquakes, landslides, volcanic eruptions, etc. Some are climatic disasters like floods, droughts, cyclones, hailstorms, etc. There are some man-induced disasters as well, like wars or battles, riots, terrorist strikes, rail or road accidents, etc. Nuclear explosions and industrial accidents also fall under man-induced disasters category as they too occur largely due to the follies of mankind.

34. EARTH QUAKES Earthquakes are tremors which are produced by the passage of vibratory waves through the rocks of the earth. They are one of the most dangerous and destructive natural hazards. Man has always fearedearthquakes. The amount of damage done by earthquakes to the life of man and property can be devastating. A brief mention of some important earthquakes is given in Next table.

35. Some of the devastating earthquakes of the world

37. One of the most notorious effects of earthquakes is the tsunami. These are giant seismic sea swells (tidal waves) which can move at 1,000 km/hr, or faster, away from the centre of an earthquake. When these swells approach the shore, they can easily reach 15 m or more. To quote, a 1960 tsunami coming from a Chilean earthquake caused 7 m breakers when it reached Hawaii fifteen hours later. Tsunamis can also be caused by underwater volcanic explosions or massive seafloor slumping. To quote, the eruption of Krakatoa volcano in Indonesia in 1883 created a 40 m high tsunami that killed more than 30,000 people on nearby Islands.

38. There is no sure way of getting protection from earthquakes. However, some ways can be deissed to offset some of the ill-effects of earthquakes. The people living in the earthquake risk zones should be educated and made aware so that they can take precautionary measures before and after the earthquakes.

39. During tremors, the following precautionary measures are suggested : • People should come out of their houses and stay in the open till the tremors subside. • Those who are already out of the houses should stay away from buildings, electric poles, trees and any tall object that has chancces of falling down. • In case there are tremors when people are in public buildings (such as offices, schools, colleges, hotels, etc.), then they should stay in the corners or near the walls, should not move about or create chaos, and remain away from heavy objects and maintain their cool. • In case a person feels the tremors while driving, he/she should stop driving and park the vehicle on the roadside and wait in the open till the vibrations subside.

40. After the tremor subsides, it is the social obligation of every human being to help those who may have suffered injuries. The following actions in response to the event are suggested : • The police control room, the fire control office, the nearby Red Cross office or the Non-Governmental Organisations (NGOs) in the area should be informed immediately. • Rescue and provide first aid to those unfortunate people who are trapped inside the buildings. If the injuries are serious they may be shifted to the nearby hospital. • Relief camps may be arranged either by the government agencies or other social groups for people whose houses and property have been damaged or have suffered injuries. As students, you should find out whether the area where you live in is a high risk zone or not. If the area is in seismic zone, you should make efforts to inform the people around you and educate them to cope with this natural calamity.

41. CYCLONES A cyclone is an area of low pressure in the centre and high pressure outside. It is a powerful swirling storm that measures from 300 to 500 km in diameter. The wind in the centre of a cyclone blows at a speed of 120 km per hour. The cyclones, thus, can be defined as travelling low pressure areas, roughly circular or oval in shape, which originate as a wave along the front separating two air masses of different temperature, density and direction. The produce clouds and rain because a warm moist air made to rise over a mass of cold air. They are known by different names over different parts of the world, such as—typhoons in China, hurricanes in Central America, willy willies in Australia and cyclones in India.

42. Some of the devastating cyclones of the world

43. The following actions could be of great help in the management of this type of natural hazard : • Identification of safe buildings in your area for safe shelters. • Listening to the weather bulletins as broadcast over the radio or telecast over television. • In the coastal areas, warning should be sent to the fishermen not to venture into sea. • Creating awareness and disseminating information among the masses. • Storage of adequate food supply. • Emergency phones and addresses should be kept ready and remain in touch with responsible members of the community. • Transport movement should be stopped during the course of storm. • Keep away from fallen electric poles, damaged bridges, etc. and avoid flood water areas. • People who have evacuated area must wait for the official declaration to come back to their homes. • Relief and rehabilitation should be immediately provided to the affected people. Relief camps should be organised in the community centres so as to provide food and shelter to the sufferers.

44. Floods The excess rain water runs through numerous channels or tributaries which feed the main river, thereby, increasing the volume of the river water. This increased volume of water sometimes cannot be contained within the banks of the rivers and, thus, overflows and causes floods. Thus, excess water that overflows stream/river banks and covers adjacent land is considered a flood. The severity of floods can be described by the depth of water above the normal stream/river banks or by how frequently a similar event normally occurs—on average—for a given area. The heavy menserval cyclonic rainfalls are the chief cause of floods. Narrowness of the river bed and blockade of the river flow by landslides are the occasional causes of floods.

45. All over the world floods have imposed untold human suffering and extracted heavy toll of losses. Cultivable and cultivated areas get submerged and eroded, leading to the loss of fertile soil as well as crops which may further lead to famines. Houses, buildings, public and private utility services and industries also face heavy damage.

46. To mitigate flood disasters, a detailed planning for prompt and efficient action in response to the anticipated event is needed. The measures include : • Forecast, warnings and advice should be provided through media (radio or television) to educate and aware people about the steps to be taken in the event of a mishap. • Valuable household items, animals and other necessary materials like food, clothes, medicines, etc. should be shifted to safer places. • Elderly people and children should be evacuated to safe shelters on emergency basis. • Government agencies and NGOs should help the flood affected people by providing public health services ; and to modify the loss, disaster relief and tax relief should be provided. • Flood management should be viewed in a broader perspective forming an integral part of overall water resource development and economic development of the area.

47. Disaster Management Disaster management can be defined as the effective organization, direction and utilization of available counter-disaster resources. These above discussed natural disasters are among the most unique and urgent situations that humans are called upon to manage. The events of a disaster move rapidly and can be extremely traumatic for those who are unprepared. Disaster managers often do not get a second chance. If a decision is wrong, the manager and the victims must live with it. Therefore, it is extremely important that disaster managers thoroughly understand their role and responsibilities and be familiar with the tools of management.

48. The role of a disaster manager can be divided into three parts : (i) Managing Operations. It involves decision-making, information management, problem solving, project and program planning, resource management and monitoring. (ii) Managing People. It includes leadership, organization, personnel management and personnel evaluation. (iii) Managing Organizations. It refers to planning, control and direction, organizational development, quality/performance control, physical control, resource management, communications and evaluation.

49. Disaster management places heavy emphasis on advance planning. Advance planning activities, collectively called disaster preparedness, include : • Strategic Planning. It consists of preparing the organization to respond to disaster threats in locations that are not specified and not immediately threatened. • Contingency Planning. It is site-specific and recognizes that a disaster could occur at any time. • Forward Planning. It occurs when a disaster is imminent and some details regarding the threat are known to the crisis manager.

50. The Indian sub-continent due to its unique geographical and geological features has the distinction of being one of the most vulnerable areas to natural disasters, causing colossal losses of life and property. Natural disasters, almost all kinds, seem to occur with a strange regularity and multiple disasters striking simultaneously in different parts of the country are not uncommon.