We investigated the distributions of phosphate (PO₄-P) and used the oxygen isotope composition of phosphate (δ¹⁸O_P) to quantify PO₄-P sources in the waters of Huangbai River. According to the environmental characteristics of Huangbai River basin, the sampling stations in the Huangbai River were divided into three groups: sampling stations in the phosphate mining area, in the outcrop area of phosphate rock, and in the residential/agricultural area. The average PO₄-P concentration was highest (2.34 ± 1.00 μmol/L) in the outcrop area of phosphate ore, intermediate in the residential/agricultural area (1.06 ± 1.21 μmol/L), and lowest in the phosphate mining area (0.58 ± 0.31 μmol/L). The δ¹⁸O_P measured in the Huangbai River waters ranged from 6.0 to 20.9‰, with the highest average value in the outcrop area of phosphate rock (average: 14.6‰ ± 3.1‰). The majority of the measured δ¹⁸O_P values in the Huangbai River deviated greatly from the expected equilibrium values, indicating that δ¹⁸O_P in this area could be used to trace PO₄-P sources. We used two end-member mixing models to quantify the contribution of PO₄-P from different sources. In the phosphate mining area, the average fractions of PO₄-P from phosphate ore and sewage were 49.5% ± 23.8% and 50.5% ± 23.8%, respectively. In the outcrop area of phosphate rock, the average fractions of PO₄-P from phosphate ore and sewage were 60.1% ± 21.7% and 39.9% ± 21.7%, respectively. In the residential/agricultural area, the average fractions of PO4-P from fertilizer and sewage were 49.2% ± 23.2% and 50.8% ± 23.2%, respectively. These results indicate that phosphate mining activities was not an important source for PO₄-P in the waters of Huangbai River. The natural weathering of phosphate rock, fertilization, and domestic sewage contributed more to the high PO₄-P concentrations in the Huangbai River waters.

我们研究了磷酸盐（PO的分布₄ -P）和使用磷酸盐的氧同位素组成（δ ¹⁸ ö _P）来定量PO ₄在黄柏河水域-P源。根据黄柏河流域的环境特征，将黄柏河的采样站分为三类：磷酸盐矿区，磷矿露头区和居民区/农业区。在磷矿露头区域，平均PO ₄ -P浓度最高（2.34±1.00μmol/ L），在居民/农业区域居中（1.06±1.21μmol/ L），在磷矿区最低（0.58） ±0.31μmol/ L）。该δ ¹⁸在黄柏河水域测得的O _P范围为6.0至20.9‰，在磷矿露头区域的平均值最高（平均值：14.6‰±3.1‰）。大多数测量的δ ^18个Ó _P在黄柏河值与预期平衡值大大偏离，这表明δ ¹⁸ ö _P在这方面的可以被用于跟踪PO _4种-P源。我们使用了两个末端成员混合模型来量化来自不同来源的PO ₄ -P的贡献。在磷酸盐矿区，PO ₄的平均含量磷矿石和污水中的磷分别为49.5％±23.8％和50.5％±23.8％。在磷矿露头地区，磷矿和污水中PO ₄ -P的平均含量分别为60.1％±21.7％和39.9％±21.7％。在住宅/农业地区，化肥和污水中的PO4-P平均含量分别为49.2％±23.2％和50.8％±23.2％。这些结果表明，磷矿的开采活动不是黄柏河水域PO ₄ -P的重要来源。磷矿的自然风化，施肥和生活污水对黄柏河水域高PO ₄ -P浓度的贡献更大。