地理研究 ›› 2006, Vol. 25 ›› Issue (1): 19-26.doi: 10.11821/yj2006010003

• 论文 • 上一篇    下一篇

湖泊沉积物对磷的吸附特征及其吸附热力学参数

王圣瑞, 金相灿, 庞燕   

  1. 中国环境科学研究院湖泊生态环境研究中心,北京100012
  • 收稿日期:2005-04-19 修回日期:2005-08-13 出版日期:2006-02-15 发布日期:2006-02-15
  • 通讯作者: 金相灿(1945-),男,浙江义乌人,研究员。主要从事湖泊富营养化研究。E-mail:Jinxiang@pub- lic.bt.a.net.cn E-mail:E-mail:Jinxiang@pub-lic.bt.a.net.cn
  • 作者简介:王圣瑞(1972-),男,内蒙古土左人,博士,副研究员。主要从事湖泊富营养化研究。E-mail:shen- gruiwang@sohu.com
  • 基金资助:

    国家重点基础研究发展规划项目“湖泊富营养化过程与蓝藻水华暴发机理研究”(2002CB412304)

The adsorption characteristics and adsorption thermodynamics parameter of phosphate on lake sediments

WANG Sheng-rui, JIN Xiang-can, PANG Yan   

  1. Research Center of Lake Eco-environment,ChineseResearch Academy of Environment Science,Beijing 100012,China
  • Received:2005-04-19 Revised:2005-08-13 Online:2006-02-15 Published:2006-02-15

摘要:

在模拟条件下研究了属于不同营养水平的3个沉积物吸附磷等温线、动力学和热力学参数,比较了不同沉积物吸附磷的差别。结论如下:(1)在本研究条件下,五里湖沉积物吸附磷的Qmax、K、NAP和EPC0均高于东太湖和贡湖沉积物,而m却较低。东太湖和贡湖沉积物与其上覆水间基本保持磷吸附-解吸动态平衡状态,五里湖沉积物有向上覆水释放磷的趋势;(2)沉积物吸附磷主要发生在00.5h之内,此时间段吸附速率为贡湖沉积物与东太湖沉积物相差不大,均高于五里湖沉积物;(3)温度对五里湖沉积物吸附磷影响相对较小,而对贡湖和东太湖沉积物影响较大。

关键词: 磷, 吸附等温线, 热力学参数, 吸附动力学, 吸附-解吸平衡浓度, 沉积物

Abstract:

The adsorption isotherms,kinetics and thermodynamics parameters of phosphate on three sediments that are in different trophic levels respectively were studied in simulated condition,and the differences of phosphate adsorption on different sediments were also compared.The conclusions are as follows. (1) The Qmax,K,m,NAP and EPC0 of phosphate adsorption on the sediments from the East Taihu and the Gonghu lakes were almost the same,and the Qmax,K,NAP and EPC0 of the two sediments were lower than that from the Wuli Lake,but m was higher.That means the Qmax and K of the sediment from the heavily polluted Wuli Lake were higher than that from the slightly polluted East Taihu and Gonghu lakes.At the same time NAP and EPC0 of the Wuli Lake were also higher,the risk of phosphorus release of the sediment from the lake was higher,and m was lower.So the polluted state of sediment has significant effect on its phosphate adsorption.For the sediments from the East Taihu and the Gonghu lakes,they maintained a phosphate adsorption-desorption equilibrium state between the sediments and the overlying water,and for the sediment from the Wuli Lake,it tended to release phosphate into the lake′s overlying water. (2) The phosphate adsorption rate of the lake sediment within 0.5 h was the highest,and was 10 times or 100 times higher than that sampled in other time intervals,so the majority of phosphate adsorption on sediment was completed within 0.5 h.The phosphate adsorption rate within 0.5 h of the sediments from the Gonghu Lake was almost the same as the sediment from the East Taihu Lake,and the rate of the two sediments was higher than that from the Wuli Lake.Phosphate adsorption on sediment mainly depends on its physical and chemical properties such as distribution of sediment grain size.In this study,the adsorption rate within 0.5 h had no strong positive correlation with its volume percentage of fine particles less than 63μm.This suggests that the phosphate adsorption on the sediments studied was not only affected by its volume percentage of the fine particles,but also by its other physical and chemical properties. (3) The adsorption isotherms of phosphate on the sediments from the Wuli,the Gonghu and the East Taihu lakes at 283 K,298 K and 308 K were studied.The results show that the adsorption process of phosphate on the sediments was the endothermic reaction as the phosphate adsorption rate increased along with the increase of temperature.ΔH0 of the sediments from the East Taihu,the Wuli and the Gonghu lakes were 7.84,15.49 and 8.59 kJ·mol-1,and ΔG0 were 8.50,5.95 and 8.07 kJ·mol-1,respectively.The effect of phosphate adsorption by temperature was lower for the sediment from the Wuli Lake,and higher for the sediments from the East Taihu and the Gonghu lakes in this study.

Key words: phosphate, adsorption isotherms, thermodynamics parameter, adsorption kinetics, adsorption-desorption equilibrium concentration, sediment