Yang Jing, Du Chengyu, Jin Xin, Lu Hengtong, Chan Qingqing, Zhang Jiaxuan, Ma Hailong, Zeng Huiying, Li Simin
School of Water Conservancy and Hydroelectric Power, Hebei University of Engineering, Handan, Hebei, 056038, China.
School of Energy and Environmental Engineering, Hebei University of Engineering, Handan, Hebei, 056038, China.
Heliyon. 2023 Oct 4;9(10):e20607. doi: 10.1016/j.heliyon.2023.e20607. eCollection 2023 Oct.
Phosphate oxygen isotope (δO) technique is an effective tool to identify the source and transformation process of phosphorus. The poor applicability of existing δO pretreatment methods for sediments hindered the large-scale application of δO technology. This paper presents an optimization framework for the pretreatment of sediment δO samples based on large-scale applications, using the Fuyang River Basin as a case study. The typical channel landscape outflow lake, South Lake, was selected as the most favorable point for assessing the applicability and optimizing the mainstream δO pretreatment method, which was achieved by clarifying the sediment environmental characteristics of South Lake. To evaluate the suitability of the Blake and McLaughlin methods in South Lake, a comparative study was carried out based on five dimensions: phosphorus recovery rate, removal efficiency of organic matter, removal efficiency of extraction liquid impurity ion, experimental time, and reagent consumption cost. The findings demonstrated that the Blake method outperformed the McLaughlin method across all five dimensions. Based on the environmental characteristics of the sediments of South Lake, the Blake method was optimized from two perspectives, namely the substitution of reagents and adjustment and optimization of experimental procedures. This resulted in an enhancement of phosphorus recovery and organic matter removal efficiency, while also reducing the experimental time required. The optimized method also yielded satisfactory results when applied to the entire watershed. This research paper can thus offer valuable technical support for the widespread application of sediment δO technology.
磷酸盐氧同位素（δO）技术是识别磷源和转化过程的有效工具。现有沉积物δO预处理方法适用性较差，阻碍了δO技术的大规模应用。本文以滏阳河流域为例，提出了基于大规模应用的沉积物δO样品预处理优化框架。选择典型河道景观出流湖泊南湖作为评估适用性和优化主流δO预处理方法的最有利点位，通过阐明南湖沉积物环境特征来实现。为评估布雷克（Blake）法和麦克劳克林（McLaughlin）法在南湖的适用性，基于磷回收率、有机质去除效率、提取液杂质离子去除效率、实验时间和试剂消耗成本五个维度进行了对比研究。结果表明，在所有五个维度上，布雷克法均优于麦克劳克林法。基于南湖沉积物的环境特征，从试剂替代以及实验程序调整和优化两个角度对布雷克法进行了优化。这提高了磷回收率和有机质去除效率，同时减少了所需的实验时间。优化后的方法应用于整个流域时也取得了令人满意的结果。因此，本研究可为沉积物δO技术的广泛应用提供有价值的技术支持。
