| The construction of Three Gorges Project will result in the formation of an over 600 km long reservoir downstream from Yichang (Hubei Province) up to Jiangjin (Chongqing Municipality). According to concerned laws and regulations in China, the solid waste under the flooding water level should be harmlessly disposed, before the reservoir stores water, so as to protect the water quality in the reservoir and the water ecotope, to satisfy the needs of water for production and life within and downstream of the reservoir area and to ensure the safe operation of the water irrigation facilities within the reservoir area. Different from other huge reservoirs, the Three Gorges Reservoir will flood a big number of scattering counties, towns and factories as well as enormous quantity of solid waste. Polluting sources are in big number and of large variety while the pollution in this area stays serious and hard to resolve. The comparatively low economic level, low urbanization degree and restrictions on land uses have resulted in quite a number of problems in the endeavor to harmlessly dispose the solid waste under the flooding level in a limited time, in particular, the waste which has been dumped in suburbs and riverside for a long time. Thus it's necessary to make a careful study of those disposal options for the domestic solid waste under the flooding level within the reservoir area.Based on the datum of current solid waste volume, waste composition, waste properties, natural conditions and economic affordability, the author has taken Fengjie County as a case, where most solid waste has been dumped under the flooding level. With analysis tools, like fuzzing mathematics, decision tree, etc, the study has been carried out both quantitatively and qualitatively on the feasible disposal options for the riverside dumps. Major conclusions are as follows:1. The total volume of dumped solid waste can't be correctly reached by simply adding up the dumped volume of past years. The total dumped volume has been affected by the waste generation quantity, dumping time, population, living standards,etc. It's estimated that the present volume of waste dumped along the riverside is 490,000 tons, among which, 170,000 tons staying over 10 years and 320,000 tons remaining for or under 10 years.2. The degradation time of domestic solid waste varies in different regions and under different city development levels. The degradation of solid waste in warm and wet small cities, within the reservoir area, will take shorter time than that in dry northern cities and in highly urbanized cities. The dumps over 10 years old in Fengjie have almost finished degradation of a total volume of 170,000 tons.3. To deal with the riverside domestic solid waste in Fengjie, the safe and feasible option will be to consolidate the already degraded waste on site, while transferring the yet degraded to the landfill site where is above the flooding level in terms of elevation. The option is to consolidate on site all solid waste in Guodichi Dumping Site (70,000 tons) on the riverside and part of the already degraded waste in Jiaochang Dumping Site (100,000 tons). At the same time, the remaining solid waste in Jiaochang Site (310,000 tons) will be removed to new landfill site over the flooding level. The waste in Wokengzi Site (10,000 tons) will be also transferred to new sanitary landfill site. The total cost is estimated RMB25.7 million.
|
PDF Full Text Request