达里诺尔湖表层沉积物中腐殖质的分布特征

基于达里诺尔湖富营养化日趋严重的现实,开展了湖泊表层沉积物中腐殖质形态空间分布和污染特征研究。结果表明,表层沉积物中腐殖质形态水平分布均表现经向分异特征,胡敏素的分布特征主导了腐殖质的水平分布格局。达里诺尔表层沉积物中胡敏素是腐殖质中的主导形态,占总有机碳的74%~94%,占腐殖质的80%~90%。深水区表层沉积物中松结态胡敏酸和稳结态胡敏酸含量高于浅水区,揭示由水深导致的氧化还原条件是影响胡敏酸分布的因素之一。腐殖质本身矿化率很低,但它能促进其他有机质的矿化,腐殖质形态与总有机碳、有机氮显著相关。达里诺尔湖表层沉积物中有机指数基本为中清洁水平,湖区西南部有机污染较湖区东北部严重,湖区西部有机污染较湖区东部严重。

The Spatial Distribution of Humus Components and Species and the Pollution Characters of the Surface Sediments in the Dailinuoer Lake,China

On the basis of the eutrophication of the Dailinuoer Lake,the spatial distribution of humus components and species and the pollution characters of the surface sidiments in this lake were discussed in this work.The results showed that the content of total organic carbon（TOC） in the surface sediments varied from 7.25 g·kg-1 to 65.54 g·kg-1 with the average of 36.37 g·kg-1;the content of humin（HM） from 6.40 g·kg-1 to 58.16 g·kg-1 with average of 32.79 g·kg-1;The contents of humic acid（HA） and fulvic acid（FA） from 0.27 g·kg-1 to 3.5 g·kg-1 and 0.27 g·kg-1 to 4.26 g·kg-1 respectively;Then the content of organic nitrogen（ON） in the surface sediments from 0.30 g·kg-1 to 8.02 g·kg-1 with average of 3.28 g·kg-1.The horizontal distribution of humus species in surface sediments indicated different character with longitude variation.The spatial distribution patterns were dominated by the humus.In surface sediments from the Dalinuoer Lake,the dominant form of humus was HM which accounted for 74%~94% of TOC and 80%~90% of humus.In the surface sediments of deepwater area the content of LCHA and SCHA was higher than shallow water area,which indicated that redox conditions caused by water depth was one of the reasons affecting the humus distribution.The mineralization rate of humic substances was low,but it could promote other organic mineralization.The species of humus and TOC,ON significantly correlated.Organic index in surface sediments was rather cleanly.Organic pollution in the southwest area was more serious than the northeast and it was more serious in the west area than the east area of the lake.