Abstract:
Generation of huge amount of solid waste and its mismanagement has become one of the major concerned social and environmental issues in both urban and rural areas. Although municipal authorities are concerned about the importance of solid waste collection and disposal and recycling but it is difficult to deal effectively with the growing amount of solid waste generated with the increase of population. Therefore, solid waste is dumped on roads and into open drains which leading to serious health risk and degradation of living environment for millions of urban people. With the advance of time special consideration for municipal solid waste is being required.
In urban areas, the most adverse impact of solid waste is incidence and prevalence of various diseases. In Dhaka, malaria, respiratory problems, eye and skin diseases are the worst impacts. Moreover, contamination of ground water and air also leads to such adverse health impacts. On the other hand, solid waste blocks the drainage system and creates flooding in the streets leading towards mosquitoes, bad odor, and inconvenience. Dhaka with its geographical and climatic conditions is prone to flooding; hence, solid waste in the streets and drains multiplies the health impacts and miseries. Most of the child mortality could be related with this problem, as contaminated ground water and malaria are the major causes for this mortality.
Gazipur is the largest city corporation of Bangladesh. The area of this city corporation is about 329.53 square kilometer and its population is about 2500000. To conduct our study Gazipur was divided into 5 zones. Wastes were collected from each zone for two seasons- dry and wet to determine seasonal comparisons. From each zone sample wastes were collected thrice. Household wastes are primary sample source. Then from a secondary and final dumping site sample wastes were collected.
The main objectives of this study were to determine waste generation rate (per capita per day) and to determine the composition waste composition in houses, secondary dumping site and final dumping site, amount of the waste that can be reduced and the possible amount of economic benefits that can be achieved through adopting 3R policy. Then suggestion for some environmental management initiatives so that a sustainable waste management system can be achieved.
A questionnaire survey was done during the collection of household wastes. From the survey information gathered from the people were about socio economic level, existing and preferable waste collection system, generation rate. After the survey was done wastes from all sources were collected and dried in sun for 24 hours separately after drying for 24-hours wastes was sorted into various components according to physical properties. Then percentages of mass of each component were determined. From the dry sample moisture content of waste and composition analysis were prepared.
From our study it has been determined that waste generation rate for the Gazipur City Corporation was 0.323 kg/capita/day depending on season and socio economic level whereas the national waste generation rate for the urban area is 0.41 kg/capita/day (Source: Waste Survey 2005) . In dry season waste generation rate is little lesser than wet season due to production of more food in wet season. Again high socio economic people generate more wastes than low
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socio economic people. Another major finding from our study is that Food and vegetable waste i.e. organic waste is the predominant component in each sampling source. Non organic recyclable components are mainly paper and plastic and others include wood, leather, glass, metal, polythene, bricks and their range by mass varies between 25% and 35% in each source.
Our study recommends that mass and volume of recyclable components are key factor in developing a healthy and economical waste management system. Recyclable wastes should be separated and only organic and non-recyclable inorganic wastes should be brought to final dumping site. Recycling at the same time can reduce landfill required to dump and produce resource. Only non-recyclable inorganic components should be dumped in earth and other organic wastes should be used for compost manufacturing.
As Gazipur is a large and densely populated city corporation, feasible and healthy management system is an obvious to employ as soon as possible. During our study another fact that was revealed is that administrational and financial framework for managing wastes in this area is inadequate and inconsistence due to new establishment of this city corporation.