Wang Shu-Jin, Liu Yun-Gen, Wang Yan, Hou Lei, Zhang Chao
College of Environmental Science and Engineering, Southwest Forestry University, Kunming 650224, China.
Research Institute of Rural Sewage Treatment, Southwest Forestry University, Kunming 650224, China.
Huan Jing Ke Xue. 2016 Dec 8;37(12):4615-4625. doi: 10.13227/j.hjkx.201605193.
The estuarine wetland of Luoshijiang River, which flows into Erhai Lake in Yunnan province, was regarded as the typical research object. Sediment samples in the estuarine wetland of Luoshijiang River were collected by the cylindrical sediment sampler and the samples were from surface layer (0-10cm), middle layer (10-30 cm), and bottom layer (30-60 cm). The vertical distribution of total nitrogen, total phosphorus, and total organic material in dry and rainy season was analyzed and contamination risk assessment of sediment was accomplished. The results showed that: ① In dry season, average concentrations of total nitrogen in sediment on surface, middle and bottom layer at estuarine wetland of Luoshijiang River were respectively 1.734, 1.453 and 1.255 g·kg, the average concentrations of total phosphorus were respectively 1.085, 1.034 and 0.992 g·kg, the average concentrations of organic material were respectively 59.051, 47.730 and 42.133 g·kg. In rainy season, average concentrations of total nitrogen in sediment on surface, middle and bottom layer at estuarine wetland of Luoshijiang River were respectively 1.147, 0.948 and 0.895 g·kg, the average concentrations of total phosphorus were respectively 0.599, 0.523 and 0.519 g·kg, the average concentrations of organic material were respectively 53.098, 46.897 and 43.395 g·kg. ② Single factor pollution index, organic nitrogen and organic index assessment were used to evaluate the contamination level of sediment, the assessment results showed that: In dry season, the contamination level of nitrogen and phosphorus in sediment was on severe level, organic material contamination was on medium level. In rainy season, the contamination levels of ON and OI were medium, and that of PI was mild. Generally, the contamination levels of nitrogen, phosphorus and organic material in sediment tendency were as follows: dry season>rainy season, and the pollution index of each layer followed the sequence of surface layer > middle layer > bottom layer, and the most extraordinary contamination of them on surface layer was uncovered whatever the season was. ③ Pollution origin of estuarine wetland of Luoshijiang River in dry and wet season had great differences, it was mainly the exogenous source in dry season, but it was the internal source in wet season; The potential risk of release of nutrient salt of sediment in dry season was higher than the wet, and the risk in the surface layer was the highest.
流入云南省洱海的罗时江河口湿地被视为典型研究对象。采用柱状沉积物采样器采集罗时江河口湿地沉积物样品，样品分别来自表层（0 - 10cm）、中层（10 - 30cm）和底层（30 - 60cm）。分析了旱季和雨季沉积物中总氮、总磷和总有机物质的垂直分布，并完成了沉积物污染风险评估。结果表明：①旱季，罗时江河口湿地沉积物表层、中层和底层总氮平均浓度分别为1.734、1.453和1.255g·kg，总磷平均浓度分别为1.085、1.034和0.992g·kg，有机物质平均浓度分别为59.051、47.730和42.133g·kg。雨季，罗时江河口湿地沉积物表层、中层和底层总氮平均浓度分别为1.147、0.948和0.895g·kg，总磷平均浓度分别为0.599、0.523和0.519g·kg，有机物质平均浓度分别为53.098、46.897和43.95g·kg。②采用单因子污染指数、有机氮和有机指数评价法对沉积物污染程度进行评价，评价结果表明：旱季，沉积物中氮、磷污染程度为重度，有机物质污染为中度。雨季，有机氮和有机指数污染程度为中度，单因子污染指数为轻度。总体而言，沉积物中氮、磷和有机物质污染程度趋势为：旱季＞雨季，各层污染指数顺序为表层＞中层＞底层，无论何季节，表层污染最为突出。③罗时江河口湿地旱季和雨季污染来源差异较大，旱季主要为外源，雨季为内源；沉积物营养盐旱季释放潜在风险高于雨季，表层风险最高。
