Fe和Al对湖泊沉积物中磷赋存形态的影响

摘要

A sequential extraction method was used to investigate the sediment phosphorus characteristics of four eutrophic lakes in China's eastern plain region and the effects of iron and aluminum on the phosphorus fractions in the sediments. The results showed that, along with the increase of eutrophic level in the lake sediments, the amounts of TP (527.35-1,432.80 mg/kg) , Tfe (8,496.63-23,071.35 mg/kg) and Tal (6 ,219.20-14,164.46 mg/kg) increased. W( Fe) and w(Al) had different effects on the content and distribution of the different phosphorus fractions in the sediments; their effects on Fe-P and Al-P were greater. The contents of Fe-P, Al-P and BD-Fe were correlated, and were related to the absorption of phosphorus from the sediments by iron and aluminum. W(Fe) and w(Al) had little effects on the content and distribution of NH4 Cl-P. However, they greatly influenced the content and distribution of NaOII85-P. Refractory phosphorus had significant correlation with w{ NaOH85-Fe) and w(NaOH85-Al) ( P < 0. 01 ) , which may be related to the formation mechanism of w( NaOHM-P). The ratios of w(Tfe) to w(TP) , w(Tal) to w(TP) , Fe to P and Al to P may have some relationship with the eutrophication level of the lakes, with smaller ratios indicating heavier lake eutrophication.%利用连续提取法研究了东部平原4个富营养化湖泊沉积物中磷的赋存特征,探讨了Fe、Al对沉积物中磷形态的影响.结果表明,富营养化程度越重的湖泊,其w(TP)(527.35-1 432.80 mg/kg)较高,w(TFe)和w(TAl)(分别为8496.63～23071.35和6219.20 -14164.46 mg/kg)也较高.w(Fe)与w(Al)对各形态磷含量及分布的影响有所不同,其中对w(Fe-P)和w(Al-P)及其分布影响较大.w(Fe-P)、w(Al-P)和w(BD-Fe)之间存在相关关系,这主要与Fe、Al吸附部分沉积物释放的磷有关；w(Fe)与w(Al)对NH4CI-P的含量及分布影响较小,而对NaOH85-P的含量及分布影响较大,w(NaOH85-P)与w(NaOH85-Fe)和w(NaOH85-Al)显著相关(P＜0.01),这可能与NaOH85-P的形成机理有关.沉积物中w(TFe)/w(TP)、w(TAl)/w(TP)、Fe/P和Al/P等比值可能与湖泊富营养化程度有关,比值越小,湖泊富营养化程度越重.