海州湾表层沉积物磷的吸附容量及潜在释放风险

Adsorption capacity and potential release risk of surface sediments in Haizhou Bay

利用磷吸附指数(PSI)、磷吸附饱和度(DPS)和磷释放风险指数(ERI)研究了2016年10月和2017年5月海州湾表层沉积物的磷吸附容量及潜在释放风险.结果显示,2016年秋季PSI变化范围为99.58～199.39[mgP/(100g)]/[μmol/L],DPS变化范围为23.118%～34.289%;2017年夏季PSI变化范围是130.29～198.57[mgP/(100g)]/[μmol/L],DPS变化范围为25.545%～42.135%,两次调查中PSI和DPS均表现出相反的平面分布趋势.PSI和Al_(ox)、Fe_(ox)呈显著正相关,说明Fe_(ox)和Al_(ox)是影响海州湾表层沉积物吸附磷的主要因素,且Fe_(ox)占主导作用;DPS与Al_(ox)和Fe_(ox)分别表现出了显著负相关性和极显著负相关性,说明Al_(ox)和Fe_(ox)含量的增大会降低表层沉积物的磷吸附饱和度.2016年10月磷释放风险指数(ERI)的变化范围为11.59%～34.18%,2017年5月磷释放风险指数(ERI)的变化范围为12.86%～32.34%,从2次调查结果整体来看,海州湾表层沉积物的磷释放风险为中度风险.

Phosphorus adsorption index（PSI）, phosphorus adsorption saturation（DPS） and phosphorus release risk index（ERI） were used to study the phosphorus adsorption capacity and potential release risk in surface sediments of Haizhou Bay in 2016（October） and 2017（May）. The results showed PSI varied from 99.58 to 199.39 [mgP/（100 g）]/[μmol/L], DPS varied from 23.118% to 34.289% in 2016, while in 2017 PSI varied from 130.29 to 198.57 [mgP/（100 g）]/[μmol/L], DPS varied from 25.545% to 42.135%, which revealed PSI and DPS had opposite plane distribution trend. PSI had evidently positive correlation with Alox and Feox that indicated Alox, Feox were the main factors affecting the adsorption of phosphorus in surface sediments, and Feox played the Dominant role. DPS had remarkably negative correlation with Alox and extremely remarkably negative correlation with Feox, respectively, which illustrated the increasing of Alox and Feox could reduce the phosphorus adsorption saturation of surface sediments. ERI varied from 11.59% to 34.18% in 2016, and from 12.86% to 32.34% in 2017, respectively, that explained the risk of phosphorus release from surface sediments in Haizhou Bay was moderate as a whole.