ABSTRACT In the enclosure method, ammonia volatilization from an enclosed soil is commonly estimated by hanging acid-soaked polyfoam pads over the soil sample in an enclosed bottle. Response surface methodology (RSM) was used to optimize polyfoam density (D), pad height (H) and pad saturation with an acid solution (S) to maximize ammonia collection in the polyfoam pads. Three central composite design (CCD) experiments with three polyfoams having low (0.013 g cm−3), medium (0.026 g cm−3), and high (0.037 g cm−3) D were conducted. The pads utilized had heights of 1.25, 2.50, and 3.75 cm saturated with an acid solution (9.8% H3PO3 plus 2% glycerol) to a weight of 5, 9, and 13 times that of the dry pad weight. Models developed for medium and high-density polyfoams were sufficiently reliable to predict ammonia collection response in terms of H and S. The response increased linearly with H and quadratically with S. High D pads collected about 13% more ammonia than that of low or medium D pads. The models predicted maximum ammonia collection in polyfoam pads of density 0.037 g cm−3, height 3.75 cm, and at acid saturation of 10.58 times of the dry pad weight.

中文翻译：

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应用响应面法优化封闭法测定氨挥发

摘要 在封闭法中，封闭土壤中氨的挥发通常是通过将浸酸的泡沫塑料垫悬挂在封闭瓶中的土壤样品上来估计的。响应面方法 (RSM) 用于优化泡沫塑料密度 (D)、垫高度 (H) 和酸溶液 (S) 的垫饱和度，以最大限度地收集泡沫塑料垫中的氨。使用具有低 (0.013 g cm-3)、中 (0.026 g cm-3) 和高 (0.037 g cm-3) D 的三种泡沫塑料进行了三个中心复合设计 (CCD) 实验。所用垫的高度为 1.25、2.50 和 3.75 厘米，用酸溶液（9.8% H3PO3 加 2% 甘油）饱和，重量为干垫重量的 5、9 和 13 倍。为中高密度泡沫塑料开发的模型足够可靠，可以根据 H 和 S 预测氨收集响应。响应随 H 线性增加，随 S 呈二次方增加。高 D 垫比低或中 D 垫收集的氨多约 13%。该模型预测密度为 0.037 g cm−3、高度为 3.75 cm 且酸饱和度为干垫重量的 10.58 倍的泡沫塑料垫中的最大氨收集量。