南四湖沉积物营养盐释放特性

Nutrient release characteristics from the sediments in Nansi Lake

通过营养盐静态释放模拟试验,研究了南四湖沉积物NH4+-N、TP和有机质(OM)的释放能力;针对微山湖区(WS)沉积物氮含量较高、释放较强的特点,为明晰WS湖区的氮释放潜力,考察了该湖区16个点位沉积物对NH4+-N的等温吸附特性.静态释放试验表明,沉积物TP和OM释放能力较弱,对南四湖上覆水水质影响不明显;而WS湖区的NH4+-N释放能力较强.WS湖区沉积物的NH4+-N等温吸附试验表明,湖心区沉积物NH4+-N释放能力最强,吸附/解吸平衡浓度(CEAC)高于1 mg.L-1的区域面积约占微山湖的1/5,该区域沉积物NH4+-N释放将会对南水北调东线调水水质产生不利影响.

This paper aimed to study the release of NH+4-N,TP and organic matter(OM) from sediments in Nansi Lake.The adsorption characteristics of nitrogen onto the sediments from 16 sampling sites in Weishanhu area was also investigated in order to further evaluate the NH+4-N release potential.The experimental results showed that the potential of TP and OM release was not significant,and would not inluence the overlying water quality in Nansi Lake.Samples from Weishanhu area showed strong NH+4-N release potential from sediment,and about 1/5 of the whole Weishanhu area sediment might have adverse effect on South-to-North Water Diversion Project(east route).In these areas,the NH+4-N adsorption/desorption equilibrium concentration is more than 1 mg · L-1,which is the water quality standard for the South-to-North Water Diversion Project(east route).