title: [Simulation of nitrate pollution in groundwater using pump-and treat optimization method].
abstract: To study the groundwater polluted by nitrate in a landfill site in Beijing, with the pump-and-treat technology, genetic algorithms (GA) and simulated annealing (SA) were used to optimize the cases of 18 planned pumping wells in the groundwater nitrate plume. The optimization method was run to determine the minimum total costs, as a result of the optimal number of wells with the optimal locations and pumping rates. The results of optimization showed that, both GA and SA optimization conditions could reach the desired results, which means that the concentration of nitrate could be reduced to 10 mg x L(-1) after 100 days pumping. However, under the GA optimization conditions, the pumping rates of well 8 and well 14 were 155 m x d(-1) and 10 m3 x d(-1), respectively. In contrast, under the SA optimization conditions, the pumping rate of well 8 was 82 m3 x d(-1), and that of well 14 was 39 m3 x d(-1). Based on the GA and SA optimized pumping rate, the total mass removal rates of nitrate were 76.89% and 84.92%, respectively. The results showed that the best location of the well was in the central axis of either midstream or downstream of the nitrate contamination plume. The pumping rate of midstream was larger than downstream. Comparison of the two optimization algorithms showed that the optimized system management cost of SA was 6.8%, which was lower than that of GA. Meanwhile, SA was easily convergent with smaller volatility.
authors.forename: Lie
authors.initials: L
authors.lastname: Jiang
authors.forename: Jiang-Tao
authors.initials: JT
authors.lastname: He
authors.forename: Yong-Hai
authors.initials: YH
authors.lastname: Jiang
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
mesh_terms: D000465:Algorithms; D002681:China; D060587:Groundwater / Q000737:chemistry*; D009566:Nitrates / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods
chemical_list: D009566:Nitrates; D014874:Water Pollutants, Chemical