Research On Remediation Of Petroleum Contaminant Naphthalene In Groundwater Systems Under Uncertainty

In the past decade, groundwater contamination caused by the petroleum products leakage from underground storage tanks and pipelines has become a major environmental concern.Thesepetroleum pollutants may pose significant threats to the underlying groundwater and the health of the neighboring communities. This provides an adequate reason for a great effort to remediate such contaminated aquifers and develop appropriate groundwater management systems. In recent years, a large number of remediation methods (i.e., pump and treat, bioremediation, surfactant-enhanced aquifer remediation, etc.) have been applied to mitigate groundwater contamination. However,a problem associated with these remediation actions is the deficiency in understanding the processes controlling the fate of contaminants may lead to a large inflation of expenses. Therefore, a parametric statistical method (SQRSA) to create a series of rapid-response and easy-to-use surrogates for capturing the relations between remediation strategies(pumping rates at the wells)and remediation performance(contaminant concentrations). SQRSA has the advantages of (1) automotive selection of potential explanatory variables (e.g., the pumping rates at various remediation wells), (2) providing a flexible manner for examining the linear, interactive, and quadratic effects of operating conditions on the naphthalene levels, and (3)alleviating the computational efforts in optimization processes. The results demonstrate that the pumping rates would be seriously influenced by the environmental standard when the optimal remediation strategy is carried out. Based on indepth analysis of prominent uncertainty in environmental standard, this study provides an integrated simulation-optimization approach for optimal design of petroleum-contaminated groundwater remediation under uncertainty. Compared to the previous approaches, it has the advantages of providing a satisfaction level that indicates the degree to which the environmental quality standard is satisfied and preventing the formulation of over optimistic and over pessimistic optimization strategies. The approach is applied to a petroleum-contaminated aquifer located in a power plant of Anhui province for identifying the optimal remediation strategies. The results show that the pumping rates of most wells would decrease under a relaxed standard or a longer remediation duration and the increased telescopic index have no serious effect on the optimal remediation strategy.