摘要
为了探索湖泊沉积物对上覆水中氮磷营养盐特别是磷(P)浓度的影响,研究了江苏西部10个湖泊沉积物P形态、吸附解吸作用和间隙水、上覆水之间扩散通量.对P形态的分级提取研究表明,各湖泊沉积物中P以无机磷为主,无机磷中生物可利用P占总磷(TP)比例较低.与苏北西部湖泊相比,苏南西部湖泊沉积物中Fe-P含量相对较高.江苏西部湖泊沉积物中氮主要以NH4+-N扩散为主,且大部分湖泊氨由上覆水向沉积物扩散,而洪泽湖、石臼湖和玄武湖NO3--N由沉积物向上覆水扩散.偏酸(pH<4)和偏碱(pH>10)条件下均有利于湖泊沉积物P的释放,除玄武湖外,其他湖泊在偏碱条件下P的释放量大于偏酸条件.沉积物对P吸附量随着温度的升高而增大,通过修正的Langmuir方程对湖泊沉积物磷吸附等温线进行拟合得到最大吸附量(Qm)、Langmuir吸附常数(k)与原有吸附态P(QNAP)参数,结果显示洪泽湖和玄武湖沉积物对P的最大吸附量较小,较易发生内源P释放.
To probe the effect of nitrogen and phosphorus(P) in sediment on aqueous nutrient concentrations,forms of phosphorus,sediment water interface diffusion fluxes and phosphorus release and adsorption of 10 lakes in the west Jiangsu province were studied.Sediments were sequentially extracted by the modified Ruttenberg’s method,and the result showed that inorganic phosphorus in sediments of the lakes was the major fraction of total phosphorus,but the proportion of bioavailable phosphorus was relatively low.Compared with the lakes in northern Jiangsu,the Fe-P was relatively high in sediments of lakes in southern Jiangsu.The diffusion fluxes of lakes were mainly based on NH+4-N diffusion in the west Jiangsu,and ions of most of lakes diffused from overlying water to sediment,NO-3-N diffused from sediment to overlying water in lakes except for Lake Hongze,Lake Shijiu and Lake Xuanwu.The condition leaning to acidic(pH〈4) or alkaline(pH〉10) was beneficial to phosphorus release,and except for Lake Xuanwu,the least amount of phosphorus released form sediment was higher in acidic condition than that in alkaline condition.The amount of phosphorus adsorption was increasing with temperature increase.Considering the phosphorus adsorption on native phosphorus polluted(NAP-polluted) sediments.All data of P adsorption on sediment samples collected from 7 lakes were fitted to the modified Langmuir model.And the values of the maximum adsorption capacity(Qm),phosphorus binding constant(k),native adsorbed exchangeable phosphorus(QNAP),were subsequently obtained.The results showed that the adsorption amount of P in Lake Hongze and Lake Xuanwu was relatively low,which were liable to release P from sediments.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2012年第9期3057-3063,共7页
Environmental Science
基金
国家水体污染控制与治理科技重大专项(2009ZX07106-001)
关键词
沉积物
磷形态
扩散通量
释放
吸附
sediment; phosphorus forms; diffusion fluxes; release; adsorption