太湖梅梁湾沉积物磷的垂直分布及环保疏浚深度的推算  

Vertical profiles of phosphorus in the sediments of Meiliang Bay of Taihu Lake in China and calculation of environmental dredging depth

作　　者：周小宁[1] 姜霞[2] 金相灿[2] 刘琨[1] 

机构地区：[1]广西大学化学化工学院,广西南宁530004 [2]中国环境科学研究院湖泊生态环境创新基地,北京100012

出　　处：《中国环境科学》2007年第4期445-449,共5页China Environmental Science

基　　金：国家自然科学基金资助项目(20507017);国家"973"项目(2002CB412304)

摘　　要：采集了太湖梅粱湾的柱状沉积物，分析和研究了沉积物中磷的形态、吸附动力学以及潜在的可交换性磷随深度的变化．结果表明，样品中各形态的磷含量随着深度增加总趋势为减小．不同深度的沉积物对磷的吸附过程具有相同的变化趋势，在前3h内。沉积物对磷的吸附速度较大；12h后，基本达到平衡．磷最大吸附量随深度的增加呈上升趋势，到达18cm后趋于平缓．样品中的潜在可交换性磷（q）的含量为2．48-17．40mmol／kg，其分配系数（Kp）为1．81～51．44m^3／kg，随深度的增加，qi和Kp均呈先增加后减小的趋势．根据疏浚后新形成的表层沉积物磷的净释放量（即表征磷释放的潜在可交换性磷与表征吸附的最大吸附量之差）的变化趋势，推算出该区域环境保护疏浚的最小深度为25cm．The core sediment columns collected from Meiliang Bay of Taihu Lake in China were used to study the contents of various phosphorous forms and adsorption kinetics and concentrations of potentially exchangeable phosphate with depths. The concentrations of various phosphorus forms in the sediment decreased with the depths in general. The P adsorption process was similar for the sediment in the different depth, whith adsorption rate was faster in the first 3h and the dynamic equilibrium achieved after 12h. The maximal P adsorption capacities increased with depths, but its rising rate became slowly at the depth of 18cm. The concentrations of potentially exchangeable phosphate （qi） for the sediments ranged from 2.48 to 17.40mmol/kg and the values of partition coefficient （Kp） varied from 1.81 to 51.44m^3/kg. The qi and Kp increasd firstly and then decrease with the depth increased. According to the variation of net concentrations of phosphorus release from the new surface layer formed by dredging, the environmental dredging depth for the studied area was 25cm.

关 键 词：磷形态 最大吸附量 潜在可交换性磷 磷净释放量 疏浚深度 

分 类 号：X522[环境科学与工程—环境工程]