摘要
采用平衡解吸法研究了沉积物不同有机矿质复合体对磷的解吸特征影响。结果表明,通过过氧化氢去除腐殖质后沉积物磷的解吸比例(Dr=0.65)大幅度增加,解吸迟滞性指数(TⅡ=0.01)显著降低,有机矿质复合体是影响磷在沉积物上固持特征的重要因素;磷在钙键和铁铝键有机矿质复体团聚结构微孔隙中引起的团聚体结构不可逆形变是导致磷解吸比例降低、解吸迟滞性指数增大的原因之一。铁铝键有机矿质复合体(Dr=0.17、TⅡ=0.32)对磷的固持能力强于钙键复合体(Dr=0.25、TⅡ=0.22),其因原因有二,三价的铁铝离子与二价的钙离子相比,更有利于复合结构的形成,铁铝键有机矿质复合体除对团聚体结构形成有重要影响外,还存在铁铝氧化物及水化氧化物对磷的配位吸附作用(相当于化学吸附),因而铁铝键有机矿质复合体对磷的固持能力比钙键复合体强得多;考查沉积物对磷的解吸特征不但要考虑腐殖质的含量,更要考虑腐殖质的复合形态,它也是影响沉积物磷解吸特征的重要因素,铁铝键有机矿质复合体、钙键有机矿质复合体携载的吸附态磷对上覆水体的释放通量可分别按其饱和吸附量17%和25%估算。
Effect of different organo-mineral complexes on desorption characteristic of phosphorus on sediment was investigated by batch experiment of equilibrium desorption. Results indicated that desorption ratio increased dramatically after humus was removed by H202 （Dr=0.65）, and desorption hysteresis index decreased simultaneously （Tn=0.01）. Organo-mineral complex was a main influencing factor in fixed and maintained characteristic of phosphorus on sediment. On the one hand, the irreversible transformation of aggregate structure on Fe/Al-bound or Ca-bound complex was fundamental cause of desorption ratio lower and hysteresis index higher. On the other hand, fixed and maintained capacity of Fe/Al-bound complex （Dry0.17, TH=0.32） was higher than Ca-bound complex （Dr=0.25, Tn =0.22）, （1）Trivalent iron ion was more favorable for complex structure formation than divalent calcium ion. （2）Besides Fe/Al-bound complex had a great effect upon aggregate structure formation, there was a Fe/A1 oxide or hydration oxide coordination sorption （chemical sorption） of phosphorus on sediment. Taking into account desorption characteristic was not only humus content, but also compound state of humus, as it was also an important factor. When regarded sorption capacity as a basic standard, releasing flux of adsorption state phosphorus on Ca-bound complex and Fe/Al-bound complex were also estimated in accordance with 25% and 17%.
出处
《生态环境学报》
CSCD
北大核心
2012年第12期1985-1991,共7页
Ecology and Environmental Sciences
基金
辽宁省教育厅科研项目(20060391)
关键词
沉积物
有机矿质复合体
磷
解吸分配系数
最大解吸量
解吸比例
解吸迟滞性指数
sediment
organo-mineral complexes
phosphorus
desorption partition coefficient
maximum desorption capacity
desorption ratio
desorption hysteresis index
