Multi Attribute Decision Making For Petroleum Contaminated Groundwater Remediation System Under Uncertainty

With the continuous development of the national industry and economy,the groundwater environment,unfortunately,has suffered nationwide pollution to different extents.In recent years,the significant rise of groundwater pollution events has caught great attention from the government and the residents in the area.Faced with the destruction of the ecological environment and the public concerns about drinking water safety,the government is supposed to take timely and effective measures to evaluate and control polluted groundwater,to alleviate the water crisis and maintain social harmony and stability.After many years of efforts,those technologies has already been sophisticated.Therefore,many scholars at home and abroad find it so difficult to make a breakthrough in a short time that they have turned their research direction to the combination of groundwater remediation system and numerical optimization techniques.On the basis of PAT and bioremediation technology,this paper integrates TOPSIS method and PROMETHEE to optimize forty alternative remediation schemes under different remediation periods.In this process,a weighted optimization model is established to solve the problem that the weight information is not completely certain.In the evaluation process,pumping rate,the average value of the residual concentration of pollutants,the total cost of remediation and health risk assessment are chosen as the evaluation index.The results show that better effect and lower health risk will be presented with more time spent on the remedy of contaminated site.However,the expense will be higher.In detail,a 5-year remediation scheme costs only $1.109×106,which eliminates the residual pollutant to 2.108mg/L,and reduce the risk of cancer to about 3.849×104;the cost of a 10-year remediation scheme is about 3 times of that of 5-year one,with residual pollutant concentration dropping to 0.228mg/L,while the risk value is lower than the 1/4 of that of 5-year one;for 15 years,its repairing costs continue to rise,more than four times of the expense for 5-year remediation,corresponding residual concentration of pollutants is 2.78% of that of 5-year remediation,and the health-risk-value is lower;and for 20 years,the cost rises to the highest,which is $11.864×106,but at the same time the residual concentration of pollutants and health risks drop down to the minimum,as low as 0.012mg/L and 0.186×104,respectively.Overall,it is worthwhile in spite of the extremely high cost for bringing better environmental benefits and lower health risks.