The Research And Application Of 3mra Model In The Decision-making For Waste Management

The multimedia risk model has been widely used due to it's authenticity during the process of the distribution, migration, conversion of pollutants in the environment. And meanwhile environmental risk assessment has been legalized. The developed countries in Northern America and Europe assess the environmental cost by using risk assessment, which provide reference to the legislation and decision-making departments. Compared with developed countries, the environmental risk assessment and related policy system in China are still in the stage of imitating.The Framework for 3MRA (Multimedia, Multipathway, and Multireceptor Risk Assessment) is an important software model being developed by the United States EPA for use in risk assessment of hazardous waste management facilities. The present paper summarized the model system structure, establishing method of database, the input and output of data, software operation in the 3MRA model. And meanwhile an example of uncertainty analysis of Benzene disposal describes the relative importance of various exposure pathways in driving risk levels for ecological receptors and human health.In this paper, 3MRA was applied to assess the environmental risks of chrome residue management project in a chromic salt factory. During the assessing process, the environmental risks before and after management in this area were simulated; meanwhile. the pollutant exposure pathways and the harm sufferers were also analyzed. To ensure the environmental risk after treatment was confined to the recommend values of OSW, the feasibility of preliminary treatment was verified and then output style of graphical representation and tabular data provided decision makers with fist-hand reference. The feasibility of the scheduled treatment methods was verified by this model. The simulation results showed that under the condition of 95% protected objects and 95% confidence level, chrome residue stacks brought significant environmental risk to this area; the carcinogenic risk level of neighboring residents came to the order of 10-4, the hazard quotient of aquatic ecology risk was above 1. The environmental risk decreased sharply after the detoxified landfill of chrome residues, which verified the feasibility of such treatment.According the actual situation, the conceiving of optimizing 3MRA has been put forward. The Cd, Pb, Zn pollution risk in tailing has been simulated by researching the Lead-zinc tailings-pile area in Shuikoushan ,Hengyang , Hunan province. The site data was corrected on the basis of local condition in this experiment. The simulation result shown that risk level matched the actual pollution index points to large extent.According to the preliminary researching results of 3MRA model, such system have high practical value. So this model need further study, which can provide our environment assessment method and related policy system with reference.