Solid Waste Management :

Ours is an age of science and around us are the ‘fairy tales of progress in the long march ‘of time. Today our life depends upon innumerable things which come in this world by the sincere efforts of our fellow scientists. In one word they can be termed as the wonders in today’s world. Because of such things tomorrows world promises to be a better place for man to live. However this situation is rapidly changing its form & on the contrary making life difficult. Let me explain why I think so.

Industrialization has increased which is causing rise of slums, filth, and squalor. Our moral and spiritual progress has failed. Thus the filth, dirt, garbage, waste are the price we are paying for modern civilization and material progress. The useless and unwanted materials which lie unused and unproductive are causing harm to our environment, which is on the verge of ecological disaster. Hence sooner or later it is important to take effective steps to avert this tragedy for the betterment of mankind .It can be done by proper management of these substances.

Material that is discarded because it has served its purpose or is no longer useful is called solid waste. Improper disposal of municipal solid waste can create unsanitary conditions, and this condition in turn can lead to pollution of environment and to outbreaks of vector-borne diseases. The sources of solid waste include residential, commercial, institutional and industrial activities. It includes decomposable food waste, dry material such as glass, paper, wood, cloth, bulky items such as old refrigerators, couches, large trees, rubber & plastic items, waste from nuclear reactors etc.

The tasks of collecting, treating and disposing of solid waste are technically challenging.
They also pose wide variety of administrative, economic and social problems that must be managed and solved. It is labor intensive activity, accounting for approx. three quarters of total cost of solid waste management. Public employees are often assigned to the task, but private companies like to do work under contract to the municipality. The task of selecting an optimal collection also plays an important part. Nowadays many communities have started conducting source separation & recycling programmers near the drop off centers started by them.

The ways of treatment and proper management of the solid waste are discussed below

Plastic: Plastics account for almost 10 % by weight of the content of municipal garbage. Plastic containers and other household products are increasingly recycled and for that they are sorted at the source before processing. Various thermoplastics may be remolded and reformed into new products. The most widely recycled types are the polythene, polyvinyl chloride, polystyrene, and polypropylene. Thermoplastics may be remolded and reformed into new products. Egg: Polyurethane and epoxy resins are ground or shredded for use as fillers or insulating materials. So called bio degradable plastics, include starches that degrade upon exposure to sunlight.

Paper and other cellulose products: One of the most readily available materials for recycling is paper. The stream of waste paper consists principally of newspaper; office, copying and writing paper; computer paper; colored paper; paper tissues and towels; boxboard (used for paper bags). These papers must be sorted before recycling. Newsprint and cardboard can be repulsed to make same material, while other types of scrap paper are recycled for use in low quality papers such as boxboard, tissues, and towels. Paper intended for printing grade products must be dinked (often using caustic soda) after pulping; for some uses the stock is bleached before pressing into sheets. Smaller amounts of recycled paper are made into cellulose insulation and other building products.
Bark, wood chips and lignin from saw mils, pulp mills, and paper mills are returned to soil as soil conditioners and fertilizers. The craft process of paper making produces a variety of liquid wastes that are sources of such valuable chemicals as turpentine, methyl alcohol, acetone, ethyl alcohol, and diethyl supplied. Sludge’s from pulp & paper manufacture and phosphate lime from fertilizer manufacture can be made into gypsum wallboard.

Rubber: Rubber is also one of the most polluting materials. Though much of the used rubber was formerly burned, burning has been greatly curtailed to prevent air pollution.
Internal recycling is common in most rubber plants; the reprocessed rubber can be used wherever premium grade rubber is not needed. The destructive distillation of scrap rubber products may, however, allow the reclamation of valuable chemicals. External recycling has proved a problem over the years; the cost of recycling old or worn out tires and other such material has far exceeded the value of the reclaimed material.

Glass: Glass makes up about 6 % by weight of the material in municipal waste streams.
Glass is an easily salvageable material, but one that is difficult to recover economically. Though enormous numbers of glass containers are used throughout the world, much of this glass is still not recycled, because the raw material are so inexpensive that there is scant economic motive to reuse them.
Another problem is that waste glass must be separated by color (i.e. clear, green, and brown) before it can be reused to make new glass containers. Despite these difficulties, anywhere from 35 to 90 % cullet ( broken or refused ) is currently used in glass production.

Animal and Fish wastes : The large increase in livestock and poultry production, has created a problem of disposing of animal wastes.
Processing of animal wastes for use as a component of animal feeds has been under intensive study, along with research on use of wastes for large scale composting and on possible dehydration of wastes for use as garden fertilizer. The waste from commercial fisheries and processing plants, including parts of fish & shell fish, contains valuable oils and large amounts of protein. Methods have been developed for converting these proteins into animal food and for the production of a paraffin fuel oil from animal wastes.

Ferrous Metals: These can be managed by internal as well as external methods. Metal cuttings or imperfect products are recycled by remolding, recasting, and redrawing entirely within steel mills. This process is cheaper than producing new metal from the basic ore.
Byproducts from the coke oven include organic compounds, hydrogen supplied, ammonia, which are purified and sold. Ammonia as an aqueous solution or combination with sulphuric acid which forms Ammonium sulphate is sold as fertilizer.
External recycling includes making of feed to electric arc and basic oxygen furnaces, from scrap steel.
One of the largest source of scrap steel is reprocessing of old automobile bodies, The average junked automobile contains about 62 % iron and steel , 28 % non ferrous metals and 10 % rubber, plastic, and textiles.
Parts such as carburetors and electrical components can be rebuilt and resold and the engine block is removed and melted down for recasting.
Automobile body is then crushed and flattened ; and then shredded to small pieces by hammer mills . Ferrous metals are then separated by powerful magnets and only the plastics , textiles & rubber are not reused . Some procedures are applied to washing machines , refrigerators , and other large steel or iron items.

Other reuse : Once glass , plastics , and metals have been removed , what remains is essentially organic waste . This waste can be biologically decomposed and turned into humus , which is useful soil conditioner . Kitchen scraps , when decomposed with leaves and grass in a compost mound , make an especially useful soil amendment , which helps to reduce the amount of material contributed by households to landfills.


Thus if the solid wastes are properly managed it helps to protect human health and safeguard environmental quality . Proper waste treatment and disposal practices may thus prevent degradation of ecosystems and neighbourhoods.
So it is purely in our hands to save this environment and to lead a healthy life .


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