This study aimed to geochemically investigate the sediments of the south Caspian Sea at different depths in summer and winter 2020. Sampling was conducted in 5 transects along the south coastline of the Caspian Sea and sediment grain size, hydrogen sulfide, Oxidation-reduction potential (Eh), total nitrogen, nitrite, nitrate, ammonium, total phosphorus, organic and inorganic phosphorous were measured. Eh values showed significant differences between seasons and between different transects ( < 0.05). Hydrogen sulfide ranged from 1.87 to 307.00 ppm. No significant difference was observed in hydrogen sulfide between seasons and among depths ( > 0.05) Total, inorganic and organic phosphorus contents were 782.96–1335.79 ppm, 639.66–1183.60 ppm, and 42.58–205.46 ppm, respectively. Total nitrogen revealed significant differences among transects ( < 0.05). Based on sediment quality guidelines, most sampling sites had alerting conditions for organic matter, and phosphorous contamination was detected at all stations. Anoxic condition was seen at most sites according to sedimentary Eh.

中文翻译：

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南里海近海和近海沉积物中硫化氢、氮和磷的分布

本研究旨在于2020年夏季和冬季对里海南部不同深度的沉积物进行地球化学研究。在里海南部海岸线的5个样带进行了采样，并对沉积物粒度、硫化氢、氧化还原电位（Eh）进行了地球化学研究。 ）、总氮、亚硝酸盐、硝酸盐、铵、总磷、有机磷和无机磷进行测量。 Eh值在季节之间和不同样带之间表现出显着差异（<0.05）。硫化氢的范围为 1.87 至 307.00 ppm。硫化氢在季节和深度之间差异不显着（>0.05），总磷、无机磷和有机磷含量分别为782.96~1335.79 ppm、639.66~1183.60 ppm、42.58~205.46 ppm。总氮显示样带之间存在显着差异（<0.05）。根据沉积物质量指南，大多数采样点都具备有机物警报条件，所有采样点均检测到磷污染。根据沉积 Eh，大多数地点都出现缺氧状况。