红枫湖沉积物和消落带土壤磷形态分布的研究

Distribution of Phosphorus Species in Sediment and Soils of Water-Level-Fluctuating Zone of Hongfeng Reservoir

应用SMT法对红枫湖水库库区沉积物与消落带土壤中总磷(TP)、无机磷(IP)、有机磷(OP)、铁/铝磷(Fe/Al-P)、钙磷(Ca-P)等5种形态磷进行测定,并分析其分布特征。结果表明,消落带土壤中TP含量在330.3 mg/kg^933.6 mg/kg之间,平均含量为559.5 mg/kg,而沉积物中TP含量在630.2 mg/kg^2 074.5 mg/kg之间,平均含量为1 380.4 mg/kg,远高于消落带样品总磷含量,表明进入水库水体中的污染物大部分经过迁移沉积于水库沉积物中。在沉积物与消落带土壤中,各种形态P表现出不同的分布特点:沉积物中IP/TP(约82.6%)高于消落带土壤(约67.7%);沉积物中IP主要为Fe/Al-P(约59.0%),Ca-P占IP比例为40.1%;消落带土壤Fe/Al-P占IP约63.0%,Ca-P占IP约33.4%;沉积物中活性磷(OP+Fe/Al-P)平均含量约923.8 mg/kg,占TP约67.4%,而消落带土壤活性磷组分(OP+Fe/Al-P)平均含量约421.8 mg/kg,占TP平均比例为75.6%。

Total phosphorus（TP）,inorganic-phosphorus（IP）,organic-phosphorus（OP）,Fe/Al-bound phosphorus（Fe/Al-P）and Ca-bound phosphorus（Ca-P）in sediments and soils of water-level-fluctuating zone of Hongfeng Reservoir were measured with the standard measurement and test procedure.Distribution of phosphorus species were analyzed.The results indicated that the TP content in soils of water-level-fluctuating zone varied 156.3 mg/kg-659.3 mg/kg with a average value of 559.5 mg/kg.In contrast,the TP content in sediments varied 630.2 mg/kg-2 074.5 mg/kg with a average value of 1 380.4 mg/kg,much higher that TP in the water-level-fluctuating zone.Therefore,it was demonstrated that the pollutants in the reservoir were transported and deposited in the reservoir sediments.Meanwhile,distribution characteristics of phosphorus species were different in the sediment and soil of water-level-fluctuating zones.The ratio of IP/TP in the sediments（average value of 82.6%）was higher than that in soils of water-level-fluctuating zone（average value of 67.7%）;the ratio of Fe/Al-P/IP was 59.0%,and the ratio of Ca-P/IP was 40.1%in the sediments,whereas they are 63.0%and33.4%respectively in the soils of water-level-fluctuating zone.The average content of active phosphorus（OP＋Fe/Al-P）in sediment was 923.8 mg/kg,the average ratio of active phosphorus in TP was 67.4%,whereas they are 421.8 mg/kg and 75.6%respectively in soils of water-level-fluctuating zone.