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Waste Disposal and Pollution Management in Urban Areas: Materials and Methods

Written By Vero Pents on June 27, 2012 | 21:12



This research is carried out by reviewing literatures on previously done work and presenting the findings in form of discussion and graphical representations.

Definition:
Solid waste could be considered as any material that is discarded because it has served its purpose or is no longer useful. Industrial solid waste is usually the by-product or end-product of materials from large-scale production factories and industries. They are often considered hazardous and are therefore toxic to the biological environment.
Domestic solid wastes are wastes originating from domestic activities such as those that emanate from household or small-scale activities. This latter type includes human and animal wastes, garbage from unwanted food items, paper and other old clothes or materials. Fluid wastes are their liquid and gas components. The conglomeration of all these waste products in a city or town is usually termed municipal solid waste. In developing nations, the waste is characterized by vegetative matters (60%), tins and cans (<10%), metals (<10%), polythene, wood and termites among others
(Fig. 1). Hazardous waste is any waste material that, when improperly handled and disposed of, can cause substantial harm to human health, death of smaller animal and plant organisms and a general breakdown and loss to the immediate ecological system. Should the situation persist, the effect of hazardous waste may lead to irreversible imbalance in the ecosystem equilibrium.Thus the safety and health of the environment are at risk due to the poisonous and toxic nature of hazardous waste. This type of waste can take the form of solids, semi-solids, fluids or sludges (Britannica Corporate Site, 2001).
Percentage of waste compositions in developing countries
Historical developments in waste management: Man started to develop elaborates sewage and other waste disposal system only about 150 years ago. A technology approach to solid-waste management began to develop in the latter part of the 19th century. Watertight garbage cans were first introduced in the developed countries and sturdier vehicles were used to collect and transport wastes. A significant development in solid-waste treatment and disposal practices was marked by the construction of the first refuse incinerator (equipment that burn up and reduce wastes tom ashes) in England in 1874 by the beginning of the 20th century, 15% of major American cities was incinerating solid waste. Even then, however, most of the largest cities were still using primitive disposal methods such as open dumping on land or in water (Britannica Corporate Site, 2001; Pakistan Environmental Protection Agency, 2005). Technological advances continued during the first half of the 20th century, including the development of garbage grinders, compaction trucks and pneumatic collection systems. By mid-century, however, it had become evident that open dumping and improper incineration of solid waste were causing problems of pollution and public health. As a result, sanitary landfills were developed to replace the practice of open dumping and to reduce the reliance on waste incineration. New refuse incinerators were designed to recover heat energy from the waste and were provided with extensive air-pollution control devices to satisfy stringent standards of air quality.
Flow chart of steps in waste management

Modern solid-waste management plants in most developed countries now emphasize the practice of recycling and waste reduction at the source, rather than incineration and land disposal

Wastes and their environmental problems: Subtle, yet notably environmental problems leading to hazardous pollution include the crude and poor industrial waste disposal system, as well as the indiscriminate and inappropriate domestic litter disposal habit evident in public places. Inefficient solid waste collection and disposal methods are common in developing urban and rural communities. In urban centers of developing nations, waste generated is a reflection of their social status. The low income people do generate more wastes than the medium and high income people
The effects and impacts seem to be more pronounced in urban areas, due to the constant pressure exerted by increased human activity and population density on the immediate environment. The result is nothing but a fifty and unsightly surrounding. Improper disposal of municipal solid waste can create unsanitary conditions and these conditions in turn can lead to pollution of the environment and to outbreaks of vectorborne diseases (that is, diseases spread mostly by rodents and insects). The tasks of collecting, treating and, disposing solid waste present complex technical challenges. They also pose a wide variety of administrative, economic and socio-cultural problems that must be managed and resolved in the developing urban and rural environments. In Dar-es-Salaam and other towns of Tanzania, deteriorating environmental conditions caused by poor waste disposal techniques have resulted in blockage of drainage, flooding, surface waters contamination and groundwater pollution (Burian and Alphonce, 2000). Similarly, lives and property have been lost and destroyed due to some negligence and ignorance of environmental pollution and bad waste disposal methods. Nearby areas experienced flood disasters, which swept off property, habitats and communities along valley planes in the Ogunpa flood disaster incident in the 1980’s at Ibadan, Nigeria. Bad waste disposal techniques along with flooding and deforestation are among the major environmental problems identified in Bauchi State, Nigeria. These have been further aggravated by lack of appropriate urban and regional planning policies. The lack of basic infrastructures for waste disposal has aggravated the problem of solid waste accumulation in the state (Federal Environmental Protection Agency, ). The lifespan of wastes is a major threat to wastes management in developed countries. Some waste could live over 100 years before decomposing as depicted in Fig.

duration of material decomposition
When industrial and domestic wastes pollute and contaminate both surface and underground water, vital aquatic resources are affected. Agricultural activities such as fertilizer and chemical applications to soil and crop fields have also proved to be hazardous to open and subsurface water resources. Other natural and anthropogenic activities that pollute and disrupt aquatic ecosystems include land erosion, gully erosion, landslides, floods, siltation, gas flaring, oil spills,sooth deposition, acid rains, biological pollution, algal population explosion, eutrophication and EIAdisapproved construction activities. These pose serious threats to coastline, swamp and other wetland ecological systems and thus engender the rich biodiversity existing in these fragile communities. The cost to clean up or to control pollution are so high and are thus not willing to pay for such management.
In some developing countries certain agencies are responsible for monitoring and controlling the activities of these industrialists, however, their efforts to adequately and efficiently curb and check pollution have not been successful. Hazardous wastes are still being dumped into rivers, seas and other open waters. Dumping across international boarders have also been reported. The case of Koko waste dumping onto Nigeria’s southern jurisdiction by foreign navigators, in the late 1980’s, is a typical example. These acts are not only socio-culturally unethical, but they are environmentally unsound. Both local and international waste disposal laws should be effectively implemented and enforced without fear or compromise. Incorruption and bribe should be turned down by authorized regulators/inspectors for the good and benefit of all in the environment.
Filthy habit is also evident when people thoughtlessly make a mess of public utilities, office premises, streets, parks and neighborhoods. Some simply conclude that someone will sweep and clean the dirt they have thrown on the floor instead of throwing it in its proper place-the trashcan or dustbin-for final proper disposal afterwards. The responsibility to clean up is that of everyone. Various sources of water supply are similarly contaminated. When this same spirit is brought into the medical arena, it is not hard to imagine the magnitude of the additional harm done to patientsthose who need to be cured of their ailments. Because of some carefree attitude and unclean personal habit, medical personnel (physician or nurse) may pass on a serious infection through unwashed hands or unsterilized apparatus.

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