基于分式析因设计(分辨度Ⅳ)的沉积物中镉与多种污染物竞争吸附规律

为揭示重金属(铅、锌、铜、镍、镉)与农药(阿特拉津、马拉硫磷、扑草净、晶体乐果、甲霜灵)在沉积物中共存时的复合污染规律,以镉为目标污染物,采用由BP神经网络模型预测的部分折叠实验及区组辅助的分辨度为Ⅳ的210-5分式析因设计,研究上述污染物因子的浓度主效应以及其二阶交互效应对目标污染物在沉积物上吸附的影响。研究发现,对分辨度为Ⅳ的210-5分式析因设计追加低水平部分折叠实验设计,可有效区分与目标污染物镉有关的二阶交互效应别名;其中,对镉在沉积物上的吸附有显著促进作用的主效应因子依次为:镉、镍;二阶交互效应依次为:镉×晶体乐果、镉×阿特拉津、铜×镉、镉×镍、马拉硫磷×晶体乐果、锌×铅、铜×铅。具有抑制影响的主效应因子依次为:铅、马拉硫磷;二阶交互效应依次为:锌×马拉硫磷、阿特拉津×马拉硫磷、镍×马拉硫磷、镉×马拉硫磷、铅×镉、镉×扑草净、铜×锌、铅×阿特拉津、锌×镉。镉的浓度主效应对镉在沉积物上的吸附的协同作用贡献率达到23.60%,而马拉硫磷的浓度主效应及其参与的二阶交互效应对镉吸附能力的拮抗作用贡献率达到22.67%。此外,与追加低水平部分折叠实验设计前相比较,对目标污染物在沉积物上吸附影响的协同作用贡献率由66.44%降低到57.49%,而拮抗作用贡献率由33.56%增加到42.51%,说明无别名结构的污染物二阶交互效应对目标污染物的复合污染不容忽视。

Characristic of competitive adsorption between cadmium and a variety of pollutants based on fractional factorial design (resolution IV)

In order to reveal the characteristic of composite contamination by heavy metals (copper, zinc, lead, cadmium, nickel) and pesticides (atrazine, malathion, prometryn, dimethoate, metalaxyl) absorbed onto the surficial sediments, a partially fold-over design predicted by BP neural network and block design assisted resolution IV of 210-5 fractional factorial design is used to identify the main effects and interactions of these ten pollution factors in levels. The study found that the aliases of second-order interaction effects related to objective pollutant cadmium can be distinguished effectively after the resolution IV of 210-5 fractional factorial design was partially-folded. The main effects of factor cadmium and factor nickel, as well as the second-order interaction effects of cadmium * dimethoate, cadmium * atrazine, copper * cadmium, cadmium * nickel, malathion * dimethoate, zinc * lead and copper * lead, have significant synergistic effect (?=0.05) to cadmium adsorption on the sediment; while the main effects of factor lead and factor malathion, as well as the second-order interaction effects of zinc * malathion, atrazine * malathion, nickel * malathion, cadmium * malathion, lead * cadmium, cadmium * prometryn, copper * zinc, lead * atrazine and zinc * cadmium, have significant antagonistic effect to cadmium adsorption on the sediment. The main effect of cadmium in levels has a contribution rate of 23.60% for synergistic effect to cadmium adsorption on the sediment, while the main effect and the second-order interaction effects of malathion in levels have a contribution rate of 22.67% for antagonistic effect to cadmium adsorption on the sediment. Moreover, compared to the original design without low-level partially fold-over, the contribution rate of synergistic effect to the objective pollutant adsorption on the sediment decreases from 66.44% to 57.49%, while the contribution rate of antagonistic effect increases from 33.56% to 42.51%, showing the significance of second-order interaction effects without alias structure in the composite contamination.