Abstract:

In order to reveal the composite contaminations characteristic of atrazine adsorption onto the surficial sediments in pesticide （dimethoate, metalaxyl, atrazine, malathion and prometryn）/heavy metals （copper, zinc, lead, cadmium and nickel） composite contamination system, a completely foldover design and confounding design assisted resolution Ⅲ of 2^10-6 fractional factorial design method and a best subset regression modeling method are used to identify the main effects and interactions of these ten pollution factors, while screening and establishing a atrazine multiple linear regression adsorption model （AT-MRAM） which includes atrazine as the dependent variable and the main effects factors and second-order interaction effects of ten pollutions were statistically significant （α=0.05） as independent variables. The study found that the main effects of lead, copper, zinc, cadmium, nickel and pesticide crystal rogor have significant effect （α=0.05） to inhibit the adsorption of atrazine on the sediment, named atrazine competitive adsorption effects, and its antagonism: Ni>Cd> crystal rogor>Zn>Pb>Cu, and antagonism account generated by heavy metals in the main effect is 63.51% of the total antagonism. Synergistic or antagonistic effects of the second-order interaction effects in nickel as the key independent variable are accounted for 35.3% of the atrazine adsorption capacity. Among them, lead, cadmium and crystal rogor inhibit the competitive adsorption of nickel and atrazine, with the adsorption of atrazine on the sediment, synergy: Cd  Nickel Lead  Nickel>Nickel crystal dimethoate, while the second-order interaction effect nickel  atrazine with nickel as the adjustment variable has the same effect with the nickel main factor about atrazine adsorption, these imply that the complexity and importance of the role of nickel in a variety of pollutants coexisting system on atrazine adsorption in the sediment. Moreover, according to the coefficient of variation of the atrazine multiple linear regression adsorption model, we also can estimate the compound pollution levels about the target pollutant on these main effects and second-order interaction effects of pollutant factors.

Key words: composite contamination, fractional factorial design, best subset regression, heavy metals, pesticide, sediments, atrazine