In situ, high-resolution measurement of labile phosphate in sediment porewater using the DET technique coupled with optimized imaging densitometry
In situ, high-resolution measurement of labile phosphate in sediment porewater using the DET technique coupled with optimized imaging densitometry
复制标题
使用 DET 技术结合优化的成像密度测定法原位高分辨率测量沉积物孔隙水中的不稳定磷酸盐
DOI：
10.1016/j.envres.2020.110107
复制
发表时间：
2020
影响因子：
8.3
通讯作者：
Zhang Hong
中科院分区：
文献类型：
--
作者：
Liu Lingxiao;Tang Wenzhong;Huang Jianyin;Teasdale Peter R.;Shu Limin;Zhang Hong
获得沉积物孔隙水中活性磷的二维分布对于了解沉积物中精细尺度的磷动员和固存过程具有重要意义。本文对基于计算机成像密度法（CID）的薄膜扩散平衡（DET）测量进行了详细的研究，并给出了最佳条件。本研究的重点是评价二维比色DET法与CID法（DET-CID法）在孔隙水不稳定磷酸盐测量中的应用。结果表明，红色通道滤波器是处理图像灵敏度最高的通道。另外，染色时间和温度对染色方法影响较大，建议染色时间为20 min，染色温度为>= 25℃。该方法对不稳定磷酸盐的最低检出限为0.300 mg P/L，最高检出限可达50.00 mg P/L。DET-CID技术可用于广泛的酸性和碱性水体（pH = 2-10，水硬度为0 ~ 2000 mg/L，如CaCO3）中不稳定磷酸盐的测定。线性回归分析表明，该方法与其他两种现有方法的结果非常相似（R-2 = 0.999）。我们的结果将为现场应用中不稳定磷酸盐的精确测量提供见解。
Obtaining two-dimensional distributions of reactive phosphorus in sediment porewater is very important for understanding fine-scale phosphorus mobilization and sequestration processes in sediments. In this study, the diffusive equilibrium in thin films (DET) measurement based on computer imaging densitometry (CID) was studied in detail with optimal conditions described. This study focuses on evaluating the two-dimensional colorimetric DET method coupled with CID (DET-CID method) for porewater labile phosphate measurements. The result shows that the red channel filter is the optimum channel for sensitivity to process the image. Additionally, staining time and temperature have great influence on the method, and 20 min staining time and >= 25 degrees C staining temperature were recommended. The minimum detection limit of labile phosphate of this method was 0.300 mg P/L, and the maximum detection limit could reach 50.00 mg P/L. The DET-CID technique can be used to measure labile phosphate in a wide range of acidic and alkaline water bodies (pH = 2-10 and water hardness from 0 to 2000 mg/L as CaCO3). The linear regression analysis shows that this technique presents very similar results compared with other two existing methods (R-2 = 0.999). Our results would give insights into the precisely measurements of labile phosphate in field applications.