Modeling approach with Box-Behnken design for optimization of Pb bioaccumulation parameters in Gammarus pulex (L., 1758)

The aim of this research was to evaluate the suitability of Gammarus pulex (L., 1758), an amphipod crustacean, as a bio-monitor for lead (Pb). A Box– Behnken experimental approach combined with response surface modeling (RSM) and quadratic programming was employed to increase the knowledge about Pb2+ bioaccumulation in Gammarus pulex (L., 1758). Independent variables, such as temperature ranging from 18 to 22 ºC, contact time from 8 to 48 hours, and Pb2+ ion solution concentrations from 50 to 100 µg L-1, were studied and tested using analysis of variance (ANOVA). The standardized effects of the independent variables and their interactions on the dependent variable were also investigated according to a Pareto chart. The selected variables' optimum values were obtained by solving the quadratic regression model along with analyzing the response surface contour plots. Optimum experimental conditions were obtained at 22.0 ºC, contact time of 8 hours, and Pb concentration at 69.5 µg L-1. Based on the Box-Behnken design, the applied model is significant because the model F-value and R2 were obtained at 77.80 and 0.9901, respectively. Bioaccumulation of Pb was determined using electrothermal atomic absorption spectrometry (ETAAS). The obtained data suggest that G. pulex can be used as a Pb biomonitor.